[Federal Register Volume 85, Number 148 (Friday, July 31, 2020)]
[Rules and Regulations]
[Pages 46302-46419]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-15651]
[[Page 46301]]
Vol. 85
Friday,
No. 148
July 31, 2020
Part III
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 218
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to the U.S. Navy Training and Testing Activities in the Mariana Islands
Training and Testing (MITT) Study Area; Final Rule
Federal Register / Vol. 85, No. 148 / Friday, July 31, 2020 / Rules
and Regulations
[[Page 46302]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
[Docket No. 200713-0188]
RIN 0648-BJ00
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to the U.S. Navy Training and Testing Activities in the
Mariana Islands Training and Testing (MITT) Study Area
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Final rule; notification of issuance of Letter of
Authorization.
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SUMMARY: NMFS, upon request from the U.S. Navy (Navy), issues these
regulations pursuant to the Marine Mammal Protection Act (MMPA) to
govern the taking of marine mammals incidental to the training and
testing activities conducted in the Mariana Islands Training and
Testing (MITT) Study Area. The Navy's activities qualify as military
readiness activities pursuant to the MMPA, as amended by the National
Defense Authorization Act for Fiscal Year 2004 (2004 NDAA). These
regulations, which allow for the issuance of a Letter of Authorization
(LOA) for the incidental take of marine mammals during the described
activities and timeframes, prescribe the permissible methods of taking
and other means of effecting the least practicable adverse impact on
marine mammal species and their habitat, and establish requirements
pertaining to the monitoring and reporting of such taking.
DATES: Effective from July 31, 2020, to July 30, 2027.
ADDRESSES: A copy of the Navy's application, NMFS' proposed and final
rules and subsequent LOA for the existing regulations, and other
supporting documents and documents cited herein may be obtained online
at: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. In case
of problems accessing these documents, please use the contact listed
here (see FOR FURTHER INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Stephanie Egger, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Purpose of Regulatory Action
These regulations, issued under the authority of the MMPA (16
U.S.C. 1361 et seq.), provide the framework for authorizing the take of
marine mammals incidental to the Navy's training and testing activities
(which qualify as military readiness activities) from the use of sonar
and other transducers and in-water detonations throughout the MITT
Study Area. The MITT Study Area includes the seas off the coasts of
Guam and the Commonwealth of the Northern Mariana Islands (CNMI), the
in-water areas around the Mariana Islands Range Complex (MIRC), the
transit corridor between the MIRC and the Hawaii Range Complex (HRC),
and select pierside and harbor locations. The transit corridor is
outside the geographic boundaries of the MIRC and represents a great
circle route across the high seas for Navy vessels transiting between
the MIRC and the HRC. The planned activities also include various
activities in Apra Harbor such as sonar maintenance alongside Navy
piers located in Inner Apra Harbor.
NMFS received an application from the Navy requesting seven-year
regulations and an authorization to incidentally take individuals of
multiple species of marine mammals (``Navy's rulemaking/LOA
application'' or ``Navy's application''). Take is anticipated to occur
by Level A and Level B harassment incidental to the Navy's training and
testing activities, with no serious injury or mortality expected or
authorized.
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
the Secretary of Commerce (as delegated to NMFS) to allow, upon
request, the incidental, but not intentional taking of small numbers of
marine mammals by U.S. citizens who engage in a specified activity
(other than commercial fishing) within a specified geographical region
if, after notice and public comment, the agency makes certain findings
and issues regulations that set forth permissible methods of taking
pursuant to that activity, as well as monitoring and reporting
requirements. Section 101(a)(5)(A) of the MMPA and the implementing
regulations at 50 CFR part 216, subpart I, provide the legal basis for
issuing this final rule and the subsequent LOAs. As directed by this
legal authority, this final rule contains mitigation, monitoring, and
reporting requirements.
Summary of Major Provisions Within the Final Rule
The following is a summary of the major provisions of this final
rule regarding the Navy's activities. Major provisions include, but are
not limited to:
The use of defined powerdown and shutdown zones (based on
activity);
Measures to eliminate the likelihood of ship strikes;
Activity limitations in certain areas and times that are
biologically important (i.e., for foraging, migration, reproduction)
for marine mammals; and
Implementation of a Notification and Reporting Plan (for
dead or live stranded marine mammals); and
Implementation of a robust monitoring plan to improve our
understanding of the environmental effects resulting from the Navy
training and testing activities.
Additionally, the rule includes an adaptive management component
that allows for timely modification of mitigation or monitoring
measures based on new information, when appropriate.
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA direct the
Secretary of Commerce (as delegated to NMFS) to allow, upon request,
the incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review and the opportunity to submit
comments.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stocks and will not have an unmitigable adverse impact on the
availability of the species or stocks for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other means of effecting the least practicable adverse
impact on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in this rule as
``mitigation measures''); and requirements pertaining to the monitoring
and reporting of such takings. The MMPA defines ``take'' to mean to
harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or
kill any marine mammal. The Analysis and Negligible
[[Page 46303]]
Impact Determination section below discusses the definition of
``negligible impact.''
The NDAA for Fiscal Year 2004 (2004 NDAA) (Pub. L. 108-136) amended
section 101(a)(5) of the MMPA to remove the ``small numbers'' and
``specified geographical region'' provisions indicated above and
amended the definition of ``harassment'' as applied to a ``military
readiness activity.'' The definition of harassment for military
readiness activities (section 3(18)(B) of the MMPA) is (i) Any act that
injures or has the significant potential to injure a marine mammal or
marine mammal stock in the wild (Level A Harassment); or (ii) Any act
that disturbs or is likely to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of natural behavioral patterns,
including, but not limited to, migration, surfacing, nursing, breeding,
feeding, or sheltering, to a point where such behavioral patterns are
abandoned or significantly altered (Level B harassment). In addition,
the 2004 NDAA amended the MMPA as it relates to military readiness
activities such that the least practicable adverse impact analysis
shall include consideration of personnel safety, practicality of
implementation, and impact on the effectiveness of the military
readiness activity.
More recently, section 316 of the NDAA for Fiscal Year 2019 (2019
NDAA) (Pub. L. 115-232), signed on August 13, 2018, amended the MMPA to
allow incidental take rules for military readiness activities under
section 101(a)(5)(A) to be issued for up to seven years. Prior to this
amendment, all incidental take rules under section 101(a)(5)(A) were
limited to five years.
Summary and Background of Request
On February 11, 2019, NMFS received an application from the Navy
for authorization to take marine mammals by Level A and Level B
harassment incidental to training and testing activities (categorized
as military readiness activities) from the use of sonar and other
transducers and in-water detonations in the MITT Study Area over a
seven-year period beginning when the current authorization expires. On
March 15, 2019, we published a notice of receipt of application (NOR)
in the Federal Register (84 FR 9495), requesting comments and
information related to the Navy's request for 30 days. On January 31,
2020, we published a notice of the proposed rulemaking (85 FR 5782) and
requested comments and information related to the Navy's request for 45
days. All comments received during the NOR and the proposed rulemaking
comment periods were considered in this final rule. Comments received
on the proposed rule are addressed in this final rule in the Comments
and Responses section. The following types of training and testing,
which are classified as military readiness activities pursuant to the
MMPA, as amended by the 2004 NDAA, will be covered under the
regulations and LOA: Amphibious warfare (in-water detonations), anti-
submarine warfare (sonar and other transducers, in-water detonations),
surface warfare (in-water detonations), and other testing and training
(sonar and other transducers). The activities will not include any pile
driving/removal or use of air guns.
This will be the third time NMFS has promulgated incidental take
regulations pursuant to the MMPA relating to similar military readiness
activities in the MITT Study Area, following those effective from
August 3, 2010, through August 3, 2015 (75 FR 45527; August 3, 2010)
and from August 3, 2015 through August 3, 2020 (80 FR 46112; August 3,
2015). For this third rulemaking, the Navy is proposing to conduct
similar activities as they have conducted over the past nine years
under the previous rulemakings.
The Navy's mission is to organize, train, equip, and maintain
combat-ready naval forces capable of winning wars, deterring
aggression, and maintaining freedom of the seas. This mission is
mandated by Federal law (10 U.S.C. 8062), which requires the readiness
of the naval forces of the United States. The Navy executes this
responsibility by training and testing at sea, often in designated
operating areas (OPAREA) and testing and training ranges. The Navy must
be able to access and utilize these areas and associated sea space and
air space in order to develop and maintain skills for conducting naval
operations. The Navy's testing activities ensure naval forces are
equipped with well-maintained systems that take advantage of the latest
technological advances. The Navy's research and acquisition community
conducts military readiness activities that involve testing. The Navy
tests ships, aircraft, weapons, combat systems, sensors, and related
equipment, and conducts scientific research activities to achieve and
maintain military readiness.
The tempo and types of training and testing activities fluctuate
because of the introduction of new technologies, the evolving nature of
international events, advances in warfighting doctrine and procedures,
and changes in force structure (e.g., organization of ships,
submarines, aircraft, weapons, and personnel). Such developments
influence the frequency, duration, intensity, and location of required
training and testing activities, but the basic nature of sonar and
explosive events conducted in the MITT Study Area has remained the
same.
The Navy's rulemaking/LOA application reflects the most up-to-date
compilation of training and testing activities deemed necessary to
accomplish military readiness requirements. The types and numbers of
activities included in the rule account for fluctuations in training
and testing in order to meet evolving or emergent military readiness
requirements. These regulations will cover training and testing
activities that will occur for a seven-year period following the
expiration of the current MMPA authorization for the MITT Study Area,
which expires on August 3, 2020.
Description of the Specified Activity
Additional detail regarding the specified activity was provided in
our Federal Register notice of proposed rulemaking (85 FR 5782; January
31, 2020); please see that notice of proposed rulemaking or the Navy's
application for more information. In addition, since publication of the
proposed rule, additional mitigation measures have been added, which
are discussed in detail in the Mitigation Measures section of this
rule. The Navy requested authorization to take marine mammals
incidental to conducting training and testing activities. The Navy has
determined that acoustic and explosive stressors are most likely to
result in impacts on marine mammals that could rise to the level of
harassment, and NMFS concurs with this determination. Descriptions of
these activities are provided in section 2 of the 2020 MITT Final
Supplemental Environmental Impact Statement (FSEIS)/Overseas EIS (OEIS)
(2020 MITT FSEIS/OEIS) (U.S. Department of the Navy, 2020) and in the
Navy's rule making/LOA application (https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities) and are summarized here.
Dates and Duration
The specified activities can occur at any time during the seven-
year period of validity of the regulations, with the exception of the
activity types and time periods for which limitations have explicitly
been identified (see Mitigation Measures section). The planned number
of training and testing activities are described in the Detailed
Description of the Specified Activities section (Table 3).
[[Page 46304]]
Geographical Region
The MITT Study Area is comprised of three components: (1) The MIRC,
(2) additional areas on the high seas, and (3) a transit corridor
between the MIRC and the HRC. The MIRC includes the waters south of
Guam to north of Pagan (CNMI), and from the Pacific Ocean east of the
Mariana Islands to the Philippine Sea to the west, encompassing 501,873
square nautical miles (nmi\2\) of open ocean. The additional areas of
the high seas include the area to the north of the MIRC that is within
the U.S. Exclusive Economic Zone (EEZ) of the CNMI and the areas to the
west of the MIRC. The transit corridor is outside the geographic
boundaries of the MIRC and represents a great circle route (i.e., the
shortest distance) across the high seas for Navy ships transiting
between the MIRC and the HRC. Although not part of any defined range
complex, the transit corridor is important to the Navy in that it
provides available air, sea, and undersea space where vessels and
aircraft conduct training and testing while in transit. While in
transit and along the corridor, vessels and aircraft will, at times,
conduct basic and routine unit-level activities such as gunnery and
sonar training. Ships also conduct sonar maintenance, which includes
active sonar transmissions.
Additionally, the MITT Study Area includes pierside locations in
the Apra Harbor Naval Complex where surface ship and submarine sonar
maintenance occur. Activities in Apra Harbor include channels and
routes to and from the Navy port in the Apra Harbor Naval Complex, and
associated wharves and facilities within the Navy port.
Primary Mission Areas
The Navy categorizes its at-sea activities into functional warfare
areas called primary mission areas. These activities generally fall
into the following eight primary mission areas: Air warfare; amphibious
warfare; anti-submarine warfare (ASW); electronic warfare;
expeditionary warfare; mine warfare (MIW); strike warfare; and surface
warfare (SUW). Most activities addressed in the MITT Study Area are
categorized under one of the primary mission areas. Activities that do
not fall within one of these areas are listed as ``other activities.''
Each warfare community (surface, subsurface, aviation, and
expeditionary warfare) may train in some or all of these primary
mission areas. The testing community also categorizes most, but not
all, of its testing activities under these primary mission areas. A
description of the sonar, munitions, targets, systems, and other
material used during training and testing activities within these
primary mission areas is provided in the 2020 MITT FSEIS/OEIS Appendix
A (Training and Testing Activities Descriptions).
The Navy describes and analyzes the effects of its activities
within the 2020 MITT FSEIS/OEIS. In its assessment, the Navy concluded
that sonar and other transducers and in-water detonations were the
stressors that would result in impacts on marine mammals that could
rise to the level of harassment as defined under the MMPA. Therefore,
the Navy's rulemaking/LOA application provides the Navy's assessment of
potential effects from these stressors in terms of the various warfare
mission areas in which they will be conducted. Those mission areas
include the following:
[ssquf] Amphibious warfare (underwater detonations)
[ssquf] ASW (sonar and other transducers, underwater detonations)
[ssquf] MIW (sonar and other transducers, underwater detonations)
[ssquf] SUW (underwater detonations)
[ssquf] Other training and testing activities (sonar and other
transducers)
The Navy's training and testing activities in air warfare,
electronic warfare, and expeditionary warfare do not involve sonar and
other transducers, underwater detonations, or any other stressors that
could result in harassment, serious injury, or mortality of marine
mammals. Therefore, the activities in air, electronic, and
expeditionary warfare areas are not discussed further in this rule, but
are analyzed fully in the 2020 MITT FSEIS/OEIS. Additional detail
regarding the primary mission areas was provided in our Federal
Register notice of proposed rulemaking (85 FR 5782; January 31, 2020);
please see that notice of proposed rulemaking or the Navy's application
for more information.
Overview of Major Training Activities and Exercises Within the MITT
Study Area
A major training exercise (MTE) for purposes of this rulemaking is
comprised of several unit-level activities conducted by several units
operating together, commanded and controlled by a single Commander, and
typically generating more than 100 hours of active sonar. These
exercises typically employ an exercise scenario developed to train and
evaluate the exercise participants in tactical and operational tasks.
In an MTE, most of the activities being directed and coordinated by the
Commander in charge of the exercise are identical in nature to the
activities conducted during individual, crew, and smaller unit-level
training events. In an MTE, however, these disparate training tasks are
conducted in concert, rather than in isolation.
Exercises may also be categorized as integrated or coordinated ASW
exercises. The distinction between integrated and coordinated ASW
exercises is how the units are being controlled. Integrated ASW
exercises are controlled by an existing command structure, and
generally occur during the Integrated Phase of the training cycle.
Coordinated exercises may have a command structure stood up solely for
the event; for example, the commanding officer of a ship may be placed
in tactical command of other ships for the duration of the exercise.
Not all integrated ASW exercises are considered MTEs, due to their
scale, number of participants, duration, and amount of active sonar.
The distinction between large, medium, and small integrated or
coordinated exercises is based on the scale of the exercise (i.e.,
number of ASW units participating), the length of the exercise, and the
total number of active sonar hours. NMFS considered the effects of all
training exercises, not just these major, integrated, and coordinated
training exercises in this rule.
Overview of Testing Activities Within the MITT Study Area
The Navy's research and acquisition community engages in a broad
spectrum of testing activities in support of the Fleet. These
activities include, but are not limited to, basic and applied
scientific research and technology development; testing, evaluation,
and maintenance of systems (missiles, radar, and sonar) and platforms
(surface ships, submarines, and aircraft); and acquisition of systems
and platforms. The individual commands within the research and
acquisition community include Naval Air Systems Command, Naval Sea
Systems Command, and Office of Naval Research.
Description of Stressors
The Navy uses a variety of sensors, platforms, weapons, and other
devices, including ones used to ensure the safety of Sailors and
Marines, to meet its mission. Training and testing with these systems
may introduce acoustic (sound) energy or shock waves from explosives
into the environment. The following subsections describe the acoustic
and explosive stressors for marine mammals and their habitat (including
prey species) within the MITT Study Area. Because of the complexity of
analyzing
[[Page 46305]]
sound propagation in the ocean environment, the Navy relied on acoustic
models in its environmental analyses and rulemaking/LOA application
that considered sound source characteristics and varying ocean
conditions across the MITT Study Area. Stressor/resource interactions
that were determined to have de minimis or no impacts (i.e., vessel,
aircraft, or weapons noise, and explosions in air) were not carried
forward for analysis in the Navy's rulemaking/LOA application. NMFS
reviewed the Navy's analysis and conclusions on de minimis sources and
finds them complete and supportable.
Acoustic stressors include acoustic signals emitted into the water
for a specific purpose, such as sonar and other transducers (devices
that convert energy from one form to another--in this case, into sound
waves), as well as incidental sources of broadband sound produced as a
byproduct of vessel movement and use of weapons or other deployed
objects. Explosives also produce broadband sound but are characterized
separately from other acoustic sources due to their unique hazardous
characteristics. Characteristics of each of these sound sources are
described in the following sections.
In order to better organize and facilitate the analysis of
approximately 300 sources of underwater sound used for training and
testing by the Navy, including sonar and other transducers and
explosives, a series of source classifications, or source bins, was
developed. The source classification bins do not include the broadband
sounds produced incidental to vessel or aircraft transits, weapons
firing, and bow shocks.
The use of source classification bins provides the following
benefits:
[ssquf] Provides the ability for new sensors or munitions to be
covered under existing authorizations, as long as those sources fall
within the parameters of a ``bin;''
[ssquf] Improves efficiency of source utilization data collection
and reporting requirements anticipated under the MMPA authorizations;
[ssquf] Ensures a conservative approach to all impact estimates, as
all sources within a given class are modeled as the most impactful
source (highest source level, longest duty cycle, or largest net
explosive weight) within that bin;
[ssquf] Allows analyses to be conducted in a more efficient manner,
without any compromise of analytical results; and
[ssquf] Provides a framework to support the reallocation of source
usage (hours/explosives) between different source bins, as long as the
total numbers of takes remain within the overall analyzed and
authorized limits. This flexibility is required to support evolving
Navy training and testing requirements, which are linked to real world
events.
Sonar and Other Transducers
Active sonar and other transducers emit non-impulsive sound waves
into the water to detect objects, navigate safely, and communicate.
Passive sonars differ from active sound sources in that they do not
emit acoustic signals; rather, they only receive acoustic information
about the environment, or listen. In this rule, the terms sonar and
other transducers will be used to indicate active sound sources unless
otherwise specified.
The Navy employs a variety of sonars and other transducers to
obtain and transmit information about the undersea environment. Some
examples are mid-frequency hull-mounted sonars used to find and track
enemy submarines; high-frequency small object detection sonars used to
detect mines; high-frequency underwater modems used to transfer data
over short ranges; and extremely high-frequency (greater than 200
kilohertz (kHz)) doppler sonars used for navigation, like those used on
commercial and private vessels. The characteristics of these sonars and
other transducers, such as source level, beam width, directivity, and
frequency, depend on the purpose of the source. Higher frequencies can
carry more information or provide more information about objects off
which they reflect, but attenuate more rapidly. Lower frequencies
attenuate less rapidly, so may detect objects over a longer distance,
but with less detail.
Additional detail regarding sound sources and platforms and
categories of acoustic stressors was provided in our Federal Register
notice of proposed rulemaking (85 FR 5782; January 31, 2020); please
see that notice of proposed rulemaking or the Navy's application for
more information.
Sonars and other transducers are grouped into classes that share an
attribute, such as frequency range or purpose of use. As detailed
below, classes are further sorted by bins based on the frequency or
bandwidth; source level; and, when warranted, the application in which
the source would be used. Unless stated otherwise, a reference distance
of 1 meter (m) is used for sonar and other transducers.
Frequency of the non-impulsive acoustic source;
[cir] Low-frequency sources operate below 1 kHz;
[cir] Mid-frequency sources operate at and above 1 kHz, up to and
including 10 kHz;
[cir] High-frequency sources operate above 10 kHz, up to and
including 100 kHz;
[cir] Very high-frequency sources operate above 100 kHz but below
200 kHz;
Sound pressure level of the non-impulsive source;
[cir] Greater than 160 decibels (dB) re 1 micro Pascal ([mu]Pa),
but less than 180 dB re 1 [mu]Pa;
[cir] Equal to 180 dB re 1 [mu]Pa and up to 200 dB re 1 [mu]Pa;
[cir] Greater than 200 dB re 1 [mu]Pa;
Application in which the source would be used;
[cir] Sources with similar functions that have similar
characteristics, such as pulse length (duration of each pulse), beam
pattern, and duty cycle.
The bins used for classifying active sonars and transducers that
are quantitatively analyzed in the MITT Study Area are shown in Table 1
below. While general parameters or source characteristics are shown in
the table, actual source parameters are classified.
Table 1--Sonar and Transducers Quantitatively Analyzed in the MITT Study
Area
------------------------------------------------------------------------
Source class category Bin Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources LF4............ LF sources equal to
that produce signals less than LF5............ 180 dB and up to 200
1 kHz. dB.
LF sources less than
180 dB.
Mid-Frequency (MF): Tactical MF1............ Hull-mounted surface
and non-tactical sources that ship sonars (e.g., AN/
produce signals between 1 and SQS-53C and AN/SQS-
10 kHz. 60).
MF1K........... Kingfisher mode
associated with MF1
sonars.
MF3............ Hull-mounted submarine
sonars (e.g., AN/BQQ-
10).
MF4............ Helicopter-deployed
dipping sonars (e.g.,
AN/AQS-22).
MF5............ Active acoustic
sonobuoys (e.g.,
DICASS).
MF6............ Underwater sound
signal devices (e.g.,
MK 84 SUS).
[[Page 46306]]
MF9............ Sources (equal to 180
dB and up to 200 dB)
not otherwise binned.
MF11........... Hull-mounted surface
ship sonars with an
active duty cycle
greater than 80
percent.
MF12........... Towed array surface
ship sonars with an
active duty cycle
greater than 80
percent.
High-Frequency (HF): Tactical HF1............ Hull-mounted submarine
and non-tactical sources that HF3............ sonars (e.g., AN/BQQ-
produce signals between 10 and 10).
100 kHz. Other hull-mounted
submarine sonars
(classified).
HF4............ Mine detection,
classification, and
neutralization sonar
(e.g., AN/SQS-20).
HF6............ Sources (equal to 180
dB and up to 200 dB)
not otherwise binned.
Anti-Submarine Warfare (ASW): ASW1........... MF systems operating
Tactical sources (e.g., active ASW2........... above 200 dB.
sonobuoys and acoustic MF Multistatic Active
countermeasures systems) used Coherent sonobuoy
during ASW training and (e.g., AN/SSQ-125).
testing activities.
ASW3........... MF towed active
acoustic
countermeasure
systems (e.g., AN/SLQ-
25).
ASW4........... MF expendable active
acoustic device
countermeasures
(e.g., MK 3).
ASW5........... MF sonobuoys with high
duty cycles.
Torpedoes (TORP): Active TORP1.......... Lightweight torpedo
acoustic signals produced by (e.g., MK 46, MK 54,
torpedoes. or Anti-Torpedo
Torpedo).
TORP2.......... Heavyweight torpedo
(e.g., MK 48).
TORP3.......... Heavyweight torpedo
(e.g., MK 48).
Forward Looking Sonar (FLS): FLS2........... HF sources with short
Forward or upward looking pulse lengths, narrow
object avoidance sonars used beam widths, and
for ship navigation and safety. focused beam
patterns.
Acoustic Modems (M): Sources M3............. MF acoustic modems
used to transmit data. (greater than 190
dB).
Synthetic Aperture Sonars SAS2........... HF SAS systems.
(SAS): Sonars used to form SAS4........... MF to HF broadband
high-resolution images of the mine countermeasure
seafloor. sonar.
------------------------------------------------------------------------
Explosives
This section describes the characteristics of explosions during
naval training and testing. The activities analyzed in the Navy's
rulemaking/LOA application that use explosives are described in
Appendix A (Training and Testing Activities Descriptions) of the 2020
MITT FSEIS/OEIS. Explanations of the terminology and metrics used when
describing explosives in the Navy's rule making/LOA application are
also in Appendix H (Acoustic and Explosive Concepts) of the 2020 MITT
FSEIS/OEIS.
The near-instantaneous rise from ambient to an extremely high peak
pressure is what makes an explosive shock wave potentially damaging.
Farther from an explosive, the peak pressures decay and the explosive
waves propagate as an impulsive, broadband sound. Several parameters
influence the effect of an explosive: The weight of the explosive in
the warhead, the type of explosive material, the boundaries and
characteristics of the propagation medium, and, in water, the
detonation depth and the depth of the receiver (i.e., marine mammal).
The net explosive weight, which is the explosive power of a charge
expressed as the equivalent weight of trinitrotoluene (TNT), accounts
for the first two parameters. The effects of these factors are
explained in Appendix H (Acoustic and Explosive Concepts) of the 2020
MITT FSEIS/OEIS.
Explosive detonations during training and testing activities are
associated with high-explosive munitions, including, but not limited
to, bombs, missiles, rockets, naval gun shells, torpedoes, mines,
demolition charges, and explosive sonobuoys. Explosive detonations
during training and testing involving the use of high-explosive
munitions (including bombs, missiles, and naval gun shells) could occur
in the air or at the water's surface. Explosive detonations associated
with torpedoes and explosive sonobuoys could occur in the water column;
mines and demolition charges could be detonated in the water column or
on the ocean bottom. Most detonations will occur in waters greater than
200 ft in depth, and greater than 3 nmi from shore, with the exception
of three existing mine warfare areas (Outer Apra Harbor, Piti, and Agat
Bay). Nearshore small explosive charges only occur at the three mine
warfare areas. Piti and Agat Bay, while nearshore, are in very deep
water and used for floating mine neutralization activities. In order to
better organize and facilitate the analysis of explosives used by the
Navy during training and testing that could detonate in water or at the
water surface, explosive classification bins were developed. The use of
explosive classification bins provides the same benefits as described
for acoustic source classification bins discussed above and in Section
1.4.1 (Acoustic Stressors) of the Navy's rulemaking/LOA application.
Explosives detonated in water are binned by net explosive weight.
The bins of explosives that are planned for use in the MITT Study Area
are shown in Table 2 below.
Table 2--Explosives Analyzed in the MITT Study Area
------------------------------------------------------------------------
Net explosive
Bin weight (lb) Example explosive source
------------------------------------------------------------------------
E1........ 0.1-0.25 Medium-caliber projectiles.
[[Page 46307]]
E2........ >0.25-0.5 Anti-swimmer grenade.
E3........ >0.5-2.5 57 mm projectile.
E4........ >2.5-5 Mine neutralization charge.
E5........ >5-10 5 in projectiles.
E6........ >10-20 Hellfire missile.
E8........ >60-100 250 lb bomb; Lightweight torpedo.
E9........ >100-250 500 lb bomb.
E10....... >250-500 1,000 lb bomb.
E11....... >500-650 Heavyweight torpedo.
E12....... >650-1,000 2,000 lb bomb.
------------------------------------------------------------------------
Notes: (1) Net Explosive Weight refers to the equivalent amount of TNT.
The actual weight of a munition may be larger due to other components;
(2) in = inch(es), lb = pound(s), ft = feet.
Propagation of explosive pressure waves in water is highly
dependent on environmental characteristics such as bathymetry, bottom
type, water depth, temperature, and salinity, which affect how the
pressure waves are reflected, refracted, or scattered; the potential
for reverberation; and interference due to multi-path propagation. In
addition, absorption greatly affects the distance over which higher-
frequency components of explosive broadband noise can propagate.
Appendix H (Acoustic and Explosive Concepts) of the 2020 MITT FSEIS/
OEIS explains the characteristics of explosive detonations and how the
above factors affect the propagation of explosive energy in the water.
Marine mammals could be exposed to fragments from underwater
explosions associated with the specified activities. When explosive
ordnance (e.g., bomb or missile) detonates, fragments of the weapon are
thrown at high-velocity from the detonation point, which can injure or
kill marine mammals if they are struck. These fragments may be of
variable size and are ejected at supersonic speed from the detonation.
The casing fragments will be ejected at velocities much greater than
debris from any target due to the proximity of the casing to the
explosive material. Risk of fragment injury reduces exponentially with
distance as the fragment density is reduced. Fragments underwater tend
to be larger than fragments produced by in-air explosions (Swisdak and
Montaro, 1992). Underwater, the friction of the water would quickly
slow these fragments to a point where they no longer pose a threat.
Opposingly, the blast wave from an explosive detonation moves
efficiently through the seawater. Because the ranges to mortality and
injury due to exposure to the blast wave are likely to far exceed the
zone where fragments could injure or kill an animal, the thresholds for
assessing the likelihood of harassment from a blast, which are also
used to inform mitigation zones, are assumed to encompass risk due to
fragmentation.
Detailed Description of the Specified Activities
Planned Training and Testing Activities
The Navy's Operational Commands and various System Commands have
identified activity levels that are needed in the MITT Study Area to
ensure naval forces have sufficient training, maintenance, and new
technology to meet Navy missions in the Pacific. Training prepares Navy
personnel to be proficient in safely operating and maintaining
equipment, weapons, and systems to conduct assigned missions. Navy
research develops new science and technology followed by concept
testing relevant to future Navy needs. Unlike other Navy range
complexes, training and testing in the MITT Study Area is more episodic
as transiting strike groups or individual units travel through on the
way to and from the Western Pacific, or forward deployed assets
temporarily travel to the MITT Study Area for individual or group
activities. This section analyzes a maximum number of activities that
could occur each year and then a maximum total of activities that could
occur over seven years. One activity, Torpedo (Explosive) Testing, does
not occur every year, but the maximum times it could occur over one
year and seven years was analyzed.
The training and testing activities that the Navy proposes to
conduct in the MITT Study Area are summarized in Table 3. The table is
organized according to primary mission areas and includes the activity
name, associated stressors, description of the activity, sound source
bin, the locations of those activities in the MITT Study Area, and the
number of activities. For further information regarding the primary
platform used (e.g., ship or aircraft type) see Appendix A (Training
and Testing Activities Descriptions) of the 2020 MITT FSEIS/OEIS.
Table 3--Training and Testing Activities Analyzed Annually and for a Seven-Year Period in the MITT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual 7-Year
Stressor category Activity Description Typical duration of Source bin 1 Location number of number of
event events events
--------------------------------------------------------------------------------------------------------------------------------------------------------
Major Training Event--Large Integrated Anti-Submarine Warfare Training (ASW)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Joint Multi-Strike Typically a 10-day Joint 10 days............ ASW2, ASW3, ASW4, Study Area; MIRC.. 1 7
Group Exercise. exercise, in which up ASW5, HF1, MF1,
to three carrier strike MF11, MF3, MF4,
groups would conduct MF5, MF12, TORP1.
training exercises
simultaneously.
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 46308]]
Major Training Event--Medium Integrated ASW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Joint Expeditionary Typically a 10-day 10 days............ ASW2, ASW3, MF1, Study Area; Apra 1 7
Exercise. exercise that could MF4, MF5, MF12. Harbor.
include a Carrier
Strike Group and
Expeditionary Strike
Group, Marine
Expeditionary Units,
Army Infantry Units,
and Air Force aircraft
together in a joint
environment that
includes planning and
execution efforts as
well as military
training activities at
sea, in the air, and
ashore.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Medium Coordinated ASW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Marine Air Ground Typically a 10-day 10 days............ ASW3, MF1, MF4, Study Area to 4 28
Task Force exercise that conducts MF12. nearshore; MIRC;
Exercise over the horizon, ship Tinian; Guam;
(Amphibious)--Batt to objective maneuver Rota; Saipan;
alion. for the elements of the Farallon De
Expeditionary Strike Medinilla.
Group and the
Amphibious Marine Air
Ground Task Force. The
exercise utilizes all
elements of the Marine
Air Ground Task Force
(Amphibious),
conducting training
activities ashore with
logistic support of the
Expeditionary Strike
Group and conducting
amphibious landings.
--------------------------------------------------------------------------------------------------------------------------------------------------------
ASW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Tracking Exercise-- Helicopter crews search 2-4 hours.......... MF4, MF5.......... Study Area >3 NM 10 70
Helicopter for, detect, and track from land;
(TRACKEX--Helo). submarines. Transit Corridor.
Acoustic.............. Torpedo Exercise-- Helicopter crews search 2-5 hours.......... MF4, MF5, TORP1... Study Area >3 NM 6 42
Helicopter for, detect, and track from land.
(TORPEX--Helo). submarines. Recoverable
air launched torpedoes
are employed against
submarine targets.
Acoustic.............. Tracking Exercise-- Maritime patrol aircraft 2-8 hours.......... MF5............... Study Area >3 NM 36 252
Maritime Patrol crews search for, from land.
Aircraft (TRACKEX-- detect, and track
Maritime Patrol submarines.
Aircraft).
Acoustic.............. Torpedo Exercise-- Maritime patrol aircraft 2-8 hours.......... MF5, TORP1........ Study Area >3 NM 6 42
Maritime Patrol crews search for, from land.
Aircraft (TORPEX-- detect, and track
Maritime Patrol submarines. Recoverable
Aircraft). air launched torpedoes
are employed against
submarine targets.
Acoustic.............. Tracking Exercise - Surface ship crews 2-4 hours.......... ASW1, ASW3, MF1, Study Area >3 NM 91 637
Surface (TRACKEX-- search for, detect, and MF11, MF12. from land*.
Surface). track submarines.
Acoustic.............. Torpedo Exercise-- Surface ship crews 2-5 hours.......... ASW3, MF1, MF5, Study Area >3 NM 6 42
Surface (TORPEX-- search for, detect, and TORP1. from land.
Surface). track submarines.
Exercise torpedoes are
used during this event.
Acoustic.............. Tracking Exercise-- Submarine crews search 8 hours............ ASW4, HF1, HF3, Study Area >3 NM 4 28
Submarine for, detect, and track MF3. from land;
(TRACKEX--Sub). submarines. Transit Corridor.
Acoustic.............. Torpedo Exercise-- Submarine crews search 8 hours............ ASW4, HF1, MF3, Study Area >3 NM 9 63
Submarine (TORPEX-- for, detect, and track TORP2. from land.
Sub). submarines. Recoverable
exercise torpedoes are
used during this event.
Acoustic.............. Small Combined Typically, a 5-day 5 days............. ASW2, ASW3, ASW4, Study Area >3 NM 38 56
Coordinated ASW exercise with multiple HF1, MF1, MF3, from land*.
exercise (Multi- ships, aircraft and MF4, MF5, MF11,
Sail/GUAMEX). submarines integrating MF12.
the use of their
sensors, including
sonobuoys, to search,
detect, and track
threat submarines.
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 46309]]
Mine Warfare
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Civilian Port Maritime security Multiple days...... HF4, SAS2......... MIRC, Mariana 1 7
Defense. personnel train to littorals, Inner
protect civilian ports and Outer Apra
and harbors against Harbor.
enemy efforts to
interfere with access
to those ports.
Explosive............. Mine Ship, small boat, and 1-4 hours.......... E4................ Study Area, 4 28
Neutralization--Re helicopter crews locate Mariana
motely Operated and disable mines using littorals, and
Vehicle Sonar (ASQ- remotely operated Outer Apra Harbor.
235 [AQS-20], SLQ- underwater vehicles.
48).
Acoustic.............. Mine Countermeasure Ship crews detect, 1-4 hours.......... HF4............... Study Area, Apra 4 28
Exercise--Surface locate, identify, and Harbor.
Ship Sonar (SQQ- avoid mines while
32, MCM). navigating restricted
areas or channels, such
as while entering or
leaving port.
Acoustic.............. Mine Countermeasure Surface ship crews 1-4 hours.......... HF4............... Study Area, Apra 4 28
Exercise--Towed detect and avoid mines Harbor.
Sonar (AQS-20). while navigating
restricted areas or
channels using towed
active sonar systems.
Explosive............. Mine Personnel disable threat Up to 4 hours...... E5, E6............ Agat Bay site, 20 140
Neutralization--Ex mines using explosive Piti, and Outer
plosive Ordnance charges. Apra Harbor.
Disposal.
Acoustic.............. Submarine Mine Submarine crews practice Varies............. HF1............... Study Area, 1 7
Exercise. detecting mines in a Mariana
designated area. Littorals, Inner/
Outer Apra Harbor.
Acoustic.............. Surface Ship Object Ship crews detect and 1-4 hours.......... MF1K.............. Study Area........ 6 42
Detection. avoid mines while
navigating restricted
areas or channels using
active sonar.
Explosive............. Underwater Navy divers conduct Varies............. E5, E6............ Agat Bay site, 45 315
Demolition various levels of Piti, and Outer
Qualification/ training and Apra Harbor.
Certification. certification in
placing underwater
demolition charges.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Surface Warfare (SUW)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Explosive............. Bombing Exercise Fixed-wing aircrews 1 hour............. E9, E10, E12...... Study Area, 37 259
(Air-to-Surface). deliver bombs against Special Use
stationary surface Airspace.
targets.
Explosive............. Gunnery Exercise Fixed-wing and 1 hour............. E1, E2............ Study Area >12 NM 120 840
(GUNEX) (Air-to- helicopter aircrews from land,
Surface)--Medium- fire medium-caliber Special Use
caliber. guns at surface targets. Airspace.
Explosive............. GUNEX (Surface-to- Small boat crews fire 1 hour............. E2................ Study Area >12 NM 20 140
Surface) Boat-- medium-caliber guns at from land,
Medium-caliber. surface targets. Special Use
Airspace.
Explosive............. GUNEX (Surface-to- Surface ship crews fire Up to 3 hours...... E5................ Study Area >12 NM 255 1,785
Surface) Ship-- large-caliber guns at from land,
Large-caliber. surface targets. Special Use
Airspace.
Explosive............. GUNEX (Surface-to- Surface ship crews fire 2-3 hours.......... E1................ Study Area >12 NM 234 1,638
Surface) Ship-- medium and small- from land,
Small- and Medium- caliber guns at surface Special Use
caliber. targets. Airspace.
Explosive............. Maritime Security Helicopter, surface Up to 3 hours...... E2................ Study Area; MIRC.. 40 280
Operations. ship, and small boat
crews conduct a suite
of maritime security
operations at sea, to
include visit, board,
search and seizure,
maritime interdiction
operations, force
protection, and anti-
piracy operations.
Explosive............. Missile Exercise Fixed-wing and 2 hours............ E6, E8, E10....... Study Area >12 NM 10 70
(Air-to-Surface) helicopter aircrews from land,
(MISSILEX [A-S]). fire air-to-surface Special Use
missiles at surface Airspace.
targets.
Explosive............. Missile Exercise Helicopter aircrews fire 1 hour............. E3................ Study Area >12 NM 110 770
(Air-to-Surface)-- both precision-guided from land,
Rocket (MISSILEX and unguided rockets at Special Use
[A-S]--Rocket). surface targets. Airspace.
[[Page 46310]]
Explosive............. Missile Exercise Surface ship crews 2-5 hours.......... E6, E10........... Study Area >50 NM 28 196
(Surface-to- defend against surface from land,
Surface). threats (ships or small Special Use
(MISSILEX [S-S])... boats) and engage them Airspace.
with missiles.
Explosive............. Sinking Exercise... Aircraft, ship, and 4-8 hours, possibly E5, E8, E10, E11, Study Area >50 NM 1 7
submarine crews over 1-2 days. E12, TORP2. from land and
deliberately sink a >1,000 fathoms
seaborne target, depth.
usually a
decommissioned ship
made environmentally
safe for sinking
according to U.S.
Environmental
Protection Agency
standards, with a
variety of ordnance.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Other Training Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Submarine Submarine crews operate Up to 2 hours...... HF1, MF3.......... Study Area, Apra 8 56
Navigation. sonar for navigation Harbor, and
and detection while Mariana littorals.
transiting into and out
of port during reduced
visibility.
Acoustic.............. Submarine Sonar Maintenance of submarine Up to 1 hour....... MF3............... Study Area; Apra 86 602
Maintenance. sonar and other system Harbor and
checks are conducted Mariana littorals.
pierside or at sea.
Acoustic.............. Surface Ship Sonar Maintenance of surface Up to 4 hours...... MF1............... Study Area; Apra 44 308
Maintenance. ship sonar and other Harbor and
system checks are Mariana littorals.
conducted pierside or
at sea.
Acoustic.............. Unmanned Underwater Units conduct training Up to 24 hours..... FLS2, M3, SAS2, MIRC; Apra Harbor 64 448
Vehicle Training. with unmanned SAS4. and Mariana
underwater vehicles littorals.
from a variety of
platforms, including
surface ships, small
boats, and submarines.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Testing Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ASW
Acoustic; Explosive... Anti-Submarine The test evaluates the 8 hours............ ASW2, ASW5, E1, Study Area >3 NM 26 182
Warfare Tracking sensors and systems E3, MF5, MF6. from land.
Test--Maritime used by maritime patrol
Patrol Aircraft aircraft to detect and
(Sonobuoys). track submarines and to
ensure that aircraft
systems used to deploy
the tracking systems
perform to
specifications and meet
operational
requirements.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Anti-Submarine This event is similar to 2-6 flight hours... MF5, TORP1........ Study Area >3 NM 20 140
Warfare Torpedo the training event from land.
Test. torpedo exercise. Test
evaluates anti-
submarine warfare
systems onboard rotary-
wing and fixed-wing
aircraft and the
ability to search for,
detect, classify,
localize, track, and
attack a submarine or
similar target.
Acoustic.............. Anti-Submarine Ships and their 1-2 weeks, with 4-8 ASW1, ASW2, ASW3, Mariana Island 100 700
Warfare Mission supporting platforms hours of active ASW5, MF12, MF4, Range Complex.
Package Testing. (e.g., helicopters and sonar use with MF5, TORP1.
unmanned aerial intervals of non-
systems) detect, activity in
localize, and prosecute between.
submarines.
Acoustic.............. At-Sea Sonar At-sea testing to ensure From 4 hours to 11 HF1, HF6, M3, MF3, Study Area........ 7 49
Testing. systems are fully days. MF9.
functional in an open
ocean environment.
Acoustic; Explosive... Torpedo (Explosive) Air, surface, or 1-2 days during ASW3, HF1, HF6, Mariana Island 3 9
Testing. submarine crews employ daylight hours. MF1, MF3, MF4, Range Complex.
explosive and non- MF5, MF6, TORP1,
explosive torpedoes TORP2, E8, E11.
against artificial
targets.
Acoustic.............. Torpedo (Non- Air, surface, or Up to 2 weeks...... ASW3, ASW4, HF1, Mariana Island 7 49
explosive) Testing. submarine crews employ HF6, LF4, MF1, Range Complex.
non-explosive torpedoes MF3, MF4, MF5,
against submarines or MF6, TORP1,
surface vessels. TORP2, TORP3.
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 46311]]
Mine Warfare
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic; Explosive... Mine Countermeasure Air, surface, and 1-10 days, with HF4, E4........... MIRC; nearshore 3 21
and Neutralization subsurface vessels intermittent use and littorals.
Testing. neutralize threat mines of countermeasure/
and mine-like objects. neutralization
systems during
this period.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Surface Warfare
--------------------------------------------------------------------------------------------------------------------------------------------------------
Explosive............. Air to Surface Fixed-wing and 2 hours............ E10............... Study Area >50 NM 4 28
Missile Test. helicopter aircrews from land.
fire air-to-surface
missiles at surface
targets.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vessel Evaluation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic.............. Undersea Warfare Ships demonstrate Up to 10 days...... HF4, MF1, MF4, MIRC.............. 1 7
Testing. capability of MF5, TORP1.
countermeasure systems
and underwater
surveillance, weapons
engagement, and
communications systems.
This tests ships'
ability to detect,
track, and engage
undersea targets.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Additional activities utilizing sources not listed in the Major Training Event and coordinated exercise bins above may occur during these exercises.
All acoustic sources which may be used during training and testing activities have been accounted for in the modeling and analysis presented in this
application and in the 2020 MITT FSEIS/OEIS.
* Includes limited occurrence within the Marpi Reef Geographic Mitigation Area and a portion of Chalan Kanoa Reef Geographic Mitigation Area outside of
3 nmi from land (see Figures 1 and 2).
Summary of Acoustic and Explosive Sources Analyzed for Training and
Testing
Tables 4 and 5 show the acoustic and explosive source classes,
bins, and quantities used in either hours or counts associated with the
Navy's training and testing activities over a seven-year period in the
MITT Study Area that were analyzed in the Navy's rulemaking/LOA
application. Table 4 describes the acoustic source classes (i.e., low-
frequency (LF), mid-frequency (MF), and high-frequency (HF)) that could
occur over seven years under the planned training and testing
activities. Acoustic source bin use in the planned activities will vary
annually. The seven-year totals for the planned training and testing
activities take into account that annual variability.
Table 4--Acoustic Source Classes Analyzed and Number Used for a Seven-Year Period for Training and Testing
activities in the MITT Study Area
----------------------------------------------------------------------------------------------------------------
7-year
Source class category Bin Description Unit Annual total
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF): Sources that LF4............... LF sources equal to H............. 1 7
produce signals less than 1 kHz. 180 dB and up to
200 dB.
LF5............... LF sources less H............. 10 65
than 180 dB.
Mid-Frequency (MF): Tactical and MF1............... Hull-mounted H............. 1,818 12,725
non-tactical sources that surface ship
produce signals between 1 and 10 sonars (e.g., AN/
kHz. SQS-53C and AN/SQS-
60).
MF1K.............. Kingfisher mode H............. 3 21
associated with
MF1 sonars.
MF3............... Hull-mounted H............. 227 1,586
submarine sonars
(e.g., AN/BQQ-10).
MF4............... Helicopter-deployed H............. 185 1,289
dipping sonars
(e.g., AN/AQS-22).
MF5............... Active acoustic C............. 2,094 14,623
sonobuoys (e.g.,
DICASS).
MF6............... Active underwater C............. 74 458
sound signal
devices (e.g., MK
84 SUS).
MF9............... Active sources H............. 29 202
(equal to 180 dB
and up to.
200 dB) not
otherwise binned.
MF11.............. Hull-mounted H............. 304 2.128
surface ship
sonars with an
active duty cycle
greater than 80%.
MF12.............. Towed array surface H............. 616 4,320
ship sonars with
an active duty
cycle greater than
80%.
High-Frequency (HF): Tactical and HF1............... Hull-mounted H............. 73 497
non-tactical sources that submarine sonars
produce signals between 10 and (e.g., AN/BQQ-10).
100 kHz.
HF3............... Other hull-mounted H............. 4 28
submarine sonars
(classified).
[[Page 46312]]
HF4............... Mine detection, H............. 1,472 10,304
classification,
and neutralization
sonar (e.g., AN/
SQS-20).
HF6............... Active sources H............. 309 2,128
(equal to 180 dB
and up to 200 dB)
not otherwise
binned.
Anti-Submarine Warfare (ASW): ASW1.............. MF systems H............. 192 1,360
Tactical sources (e.g., active operating above
sonobuoys and acoustic 200 dB.
countermeasures systems) used
during ASW training and testing
activities.
ASW2.............. MF Multistatic C............. 554 3,878
Active Coherent
sonobuoy (e.g., AN/
SSQ-125).
ASW3.............. MF towed active H............. 3,124 21,863
acoustic
countermeasure
systems (e.g., AN/
SLQ-25).
ASW4.............. MF expendable C............. 332 2,324
active acoustic
device
countermeasures
(e.g., MK 3).
ASW5.............. MF sonobuoys with H............. 50 350
high duty cycles.
Torpedoes (TORP): Source classes TORP1............. Lightweight torpedo C............. 71 485
associated with the active (e.g., MK 46, MK
acoustic signals produced by 54, or Anti-
torpedoes. Torpedo Torpedo).
TORP2............. Heavyweight torpedo C............. 62 398
(e.g., MK 48).
TORP3............. Heavyweight torpedo C............. 6 42
test (e.g., MK 48).
Forward Looking Sonar (FLS): FLS2.............. HF sources with H............. 4 28
Forward or upward looking object short pulse
avoidance sonars used for ship lengths, narrow
navigation and safety. beam widths, and
focused beam
patterns.
Acoustic Modems (M): Systems used M3................ MF acoustic modems H............. 31 216
to transmit data through the (greater than 190
water. dB).
Synthetic Aperture Sonars (SAS): SAS2.............. HF SAS systems..... H............. 449 3,140
Sonars in which active acoustic
signals are post-processed to
form high-resolution images of
the seafloor.
SAS4.............. MF to HF broadband H............. 6 42
mine
countermeasure
sonar.
----------------------------------------------------------------------------------------------------------------
Notes: H= hours; C = count.
Table 5 describes the number of in-water explosives that could be
used in any year under the planned training and testing activities.
Under the planned activities, bin use will vary annually, and the
seven-year totals for the planned training and testing activities take
into account that annual variability.
Table 5--Explosive Source Bins Analyzed and Number Used Annually and for
a Seven-Year Period for Training and Testing Activities Within the MITT
Study Area
------------------------------------------------------------------------
Net explosive Example Explosive 7-year
Bin weight (lb) Source Annual total
------------------------------------------------------------------------
E1............. 0.1-0.25 Medium-caliber 768 5,376
projectiles.
E2............. >0.25-0.5 Anti-swimmer 400 2,800
grenade.
E3............. >0.5-2.5 57 mm projectile. 683 4,591
E4............. >2.5-5 Mine 44 308
neutralization
charge.
E5............. >5-10 5 in projectiles. 1,221 8,547
E6............. >10-20 15 lb shaped 29 203
charge.
E8............. >60-100 250 lb bomb; 134 932
Light weight
torpedo.
E9............. >100-250 500 lb bomb...... 110 770
E10............ >250-500 1,000 lb bomb.... 78 546
E11............ >500-650 Heavy weight 5 17
torpedo.
E12............ >650-1,000 2,000 lb bomb.... 48 336
------------------------------------------------------------------------
Notes: (1) net explosive weight refers to the equivalent amount of TNT.
The actual weight of a munition may be larger due to other components.
(2) in = inch(es), lb = pound(s), ft = feet.
Vessel Movement
The only areas with projected high concentrations of Navy vessel
movement will be within Apra Harbor Guam and the coastal approaches to
and from Apra Harbor. Some amphibious training events use Tinian as a
landing area so amphibious ships could occur in the offshore waters off
that island. Most other activities are spread throughout the greater
MITT Study Area with a high degree of spatial and temporal separation
between activities. Additional detail on vessel movement was provided
in our Federal Register notice of proposed rulemaking (85 FR 5782;
January 31, 2020); please see that notice of proposed rulemaking or the
[[Page 46313]]
Navy's application for more information.
The Navy tabulated annual at-sea vessel steaming days for training
and testing activities projected for the MITT Study Area. Across all
warfare areas and activities, 493 days of Navy at-sea time will occur
annually for training and testing activities in the MITT Study Area
(Table 6). Amphibious Warfare activities account for 48 percent of
total surface ship days, MTEs account for 38 percent, ASW activities
account for 8 percent, and Air Warfare, ASW, and Other activities
(sonar maintenance, anchoring) account for 2 percent each (Table 6). In
comparison to the Hawaii-Southern California Training and Testing
(HSTT) Study Area, the estimated number of at-sea annual days for
training and testing activities in the MITT Study Area is approximately
ten times less than in the HSTT Study Area over the same time period.
Table 6--Annual Navy Surface Ship Days Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Percent by Annual days by Percent by
MITT events Annual days event warfare area warfare area
----------------------------------------------------------------------------------------------------------------
Air Warfare..................................... .............. .............. 9 1.9
GUNNEX (Lg)................................. 2 0.3
GUNNEX (Sm)................................. 3 0.6
MISSILEX.................................... 5 0.9
Amphibious Warfare.............................. .............. .............. 299 60.7
Fire Support (Land Target).................. 5 1.0
Amphibious Rehearsal........................ 144 29.2
Amphibious Assault.......................... 14 2.8
Amphibious Raid............................. 3 0.6
Marine Air Ground Task Force Exercise....... 40 8.1
Non-Combatant Evacuation Op................. 67 13.5
Humanitarian Assist/Disaster Relief Op...... 7 1.4
Special Purpose............................. 20 4.1
Marine Air Ground Task Force Exercise.......
Surface Warfare................................. .............. .............. 41 8.4
MISSILEX.................................... 2 0.4
GUNNEX (Lg)................................. 14 2.8
GUNNEX (Med)................................ 10 2.0
GUNNEX (Sm)................................. 6 1.3
SINKEX...................................... 7 1.4
Maritime Security Op........................ 3 0.5
Anti-Submarine Warfare.......................... .............. .............. 8 1.6
Tracking Exercise........................... 8 1.5
Torpedo Exercise............................ 1 0.1
Major Training Exercises........................ .............. .............. 125 24.5
Joint Expeditionary Exercise................ 63 12.9
Joint Multi-Strike Group Exercise........... 62 12.5
Other........................................... .............. .............. 10 2.1
Surface Ship Sonar Maintenance.............. 7 1.5%
Precision Anchoring......................... 3 0.6%
---------------------------------------------------------------
Total................................... 493
----------------------------------------------------------------------------------------------------------------
Additional details on Navy at-sea vessel movement are provided in
the 2020 MITT FSEIS/OEIS.
Standard Operating Procedures
For training and testing to be effective, personnel must be able to
safely use their sensors and weapon systems as they are intended to be
used in military missions and combat operations and to their optimum
capabilities. While standard operating procedures are designed for the
safety of personnel and equipment and to ensure the success of training
and testing activities, their implementation often yields additional
benefits on environmental, socioeconomic, public health and safety, and
cultural resources.
Because standard operating procedures are essential to safety and
mission success, the Navy considers them to be part of the planned
Specified Activities, and has included them in the environmental
analysis. Additional details on standard operating procedures were
provided in our Federal Register notice of proposed rulemaking (85 FR
5782; January 31, 2020); please see that notice of proposed rulemaking
or the Navy's application for more information.
Comments and Responses
We published the proposed rule in the Federal Register on January
31, 2020 (85 FR 5782), with a 45-day comment period. With that proposed
rule, we requested public input on our analyses, our preliminary
findings, and the proposed regulations, and requested that interested
persons submit relevant information and comments. During the 45-day
comment period, we received 16 comment letters in total. Of this total,
one submission was from another Federal agency, one was from the Marine
Mammal Commission, three letters were from organizations or individuals
acting in an official capacity (e.g., non-governmental organizations
(NGOs), and 11 submissions were from private citizens. NMFS has
reviewed and considered all public comments received on the proposed
rule and issuance of the LOA. General comments that did not provide
information pertinent to NMFS' decisions have been noted, but are not
addressed further. All substantive comments and our responses are
described below. We provide no response to specific comments that
addressed species or statutes not relevant to the rulemaking under
section 101(a)(5)(A) of the MMPA (e.g., comments related to sea
turtles). We organize our comment responses by major categories.
[[Page 46314]]
General Comments
Comment 1: The Navy must be required to submit a Habitat
Conservation Plan that will ensure the well being of those mammals to
the best extent possible.
Response: A Habitat Conservation Plan (HCP) is a planning document
for non-Federal agencies and persons to obtain an ESA incidental take
permit under section 10(a)(1)(B) of the Endangered Species Act (ESA).
The Navy is a Federal agency that consulted with NMFS under section 7
of the ESA, and therefore obtaining a separate ESA incidental take
permit is not required. The Navy will comply with the Reasonable and
Prudent Measures and Terms and Conditions that are part of their
Incidental Take Statement, which was issued as part of the consultation
process under section 7 of the ESA.
Impact Analysis and Thresholds
Comment 2: A commenter recommended that NMFS clarify whether and
how the Navy incorporated uncertainty in its density estimates for its
animat modeling specific to MITT and if uncertainty was not
incorporated, re-estimate the numbers of marine mammal takes based on
the uncertainty inherent in the density estimates provided in
Department of the Navy (2018b).
Response: Uncertainty was incorporated into the density estimates
used for modeling and estimating take for NMFS' rule. The commenter is
referred to the technical report titled ``Quantifying Acoustic Impacts
on Marine Mammals and Sea Turtles: Methods and Analytical Approach for
Phase III Training and Testing'' (U.S. Department of the Navy, 2018)
for clarification on the consideration of uncertainty in density
estimates. See specifically Section 4.2 (Marine Species Distribution
Builder) of the 2020 MITT FSEIS/OEIS where details are provided on how
statistical uncertainty surrounding density estimates was incorporated
into the modeling for the MITT Study Area, as has been done for all
other recent NMFS and Navy analyses of training and testing at sea. To
the Commenters more specific question, as with the 2018 HSTT final
rule, a lognormal distribution was used in the density regression
model. Uncertainty was incorporated into the take estimation through
the density estimates and it is not necessary to re-estimate the take
numbers for marine mammals.
Comment 3: A Commenter stated that NMFS has largely followed the
Navy in revising its hearing loss thresholds to reflect certain new
data and modeling approaches. The Commenter suggested they have
previously advised that the criteria that NMFS produced to estimate
temporary and permanent threshold shift in marine mammals are erroneous
and non-conservative. According to the Commenter, Wright (2015) has
identified several statistical and numerical faults in NMFS' approach,
such as pseudo-replication and inconsistent treatment of data, that
tend to bias the criteria towards an underestimation of effects. The
Commenter stated that similar and additional issues were raised by a
dozen scientists during the public comment period on the draft criteria
held by NMFS. The Commenter asserts that the issue is NMFS' broad
extrapolation from a small number of individual animals, mostly
bottlenose dolphins, without taking account of what Racca et al.
(2015b) have succinctly characterized as a ``non-linear accumulation of
uncertainty.'' The Commenter asserts that NMFS failed to address the
basic errors identified by these and other experts, nor did it perform
a sensitivity analysis to understand the potential magnitude of those
errors. The Commenter suggests that NMFS should not rely exclusively on
its auditory guidance in determining ``Level A'' take, but should, at
minimum, produce a conservative upper bound such as by retaining the
180 dB threshold, or by performing a sensitivity analysis.
Response: The Acoustic Technical Guidance updates the historical
180 dB rms injury threshold, which was based on professional judgement
(i.e., no data were available on the effects of noise on marine mammal
hearing at the time this original threshold was derived). NMFS
disagrees with any suggestion that the use of the Acoustic Technical
Guidance provides erroneous results. The 180 dB rms threshold is
plainly outdated, as the best available science indicates that rms SPL
is not even an appropriate metric by which to gauge potential auditory
injury. Further, NMFS disagrees with the suggestion that NMFS should
not rely exclusively on its Technical Guidance in determining take by
Level A harassment and should instead also produce an upper bound
(either by retaining the 180-dB threshold or performing a sensitivity
analysis). The Acoustic Technical Guidance represents the best
available science and provides thresholds and weighting functions that
allow us to predict when marine mammals are likely to incur permanent
threshold shift (PTS). As described in the Estimated Take of Marine
Mammals section, when the acoustic thresholds, the Navy model, and
other inputs into the take calculation are considered, the authorized
incidental takes represent the maximum number of instances in which
marine mammals are reasonably expected to be taken, which is
appropriate under the statute and there is no need or requirement for
NMFS to authorize a larger number.
Multiple studies from humans, terrestrial mammals, and marine
mammals have demonstrated less temporary threshold shift (TTS) from
intermittent exposures compared to continuous exposures with the same
total energy because hearing is known to experience some recovery in
between noise exposures, which means that the effects of intermittent
noise sources such as tactical sonars are likely overestimated. Marine
mammal TTS data have also shown that, for two exposures with equal
energy, the longer duration exposure tends to produce a larger amount
of TTS. Most marine mammal TTS data have been obtained using exposure
durations of tens of seconds up to an hour, much longer than the
durations of many tactical sources (much less the continuous time that
a marine mammal in the field would be exposed consecutively to those
levels), further suggesting that the use of these TTS data are likely
to overestimate the effects of sonars with shorter duration signals.
Regarding the suggestion of pseudoreplication and erroneous models,
since marine mammal hearing and noise-induced hearing loss data are
limited, both in the number of species and in the number of individuals
available, attempts to minimize pseudoreplication would further reduce
these already limited data sets. Specifically, with marine mammal
behaviorally derived temporary threshold shift studies, behaviorally
derived data are only available for two mid-frequency cetacean species
(bottlenose dolphin, beluga) and two phocids (in-water) pinniped
species (harbor seal and northern elephant seal), with otariid (in-
water) pinnipeds and high-frequency cetaceans only having behaviorally-
derived data from one species. Arguments from Wright (2015) regarding
pseudoreplication within the TTS data are therefore largely irrelevant
in a practical sense because there are so few data. Multiple data
points were not included for the same individual at a single frequency.
If multiple data existed at one frequency, the lowest TTS onset was
always used. There is only a single frequency where TTS onset data
exist for two individuals of the same species: 3 kHz for bottlenose
dolphins. Their TTS (unweighted) onset values
[[Page 46315]]
were 193 and 194 dB re 1 [mu]Pa2s. Thus, NMFS believes that the current
approach makes the best use of the given data. Appropriate means of
reducing pseudoreplication may be considered in the future, if more
data become available. Many other comments from Wright (2015) and the
comments from Racca et al. (2015b) appear to be erroneously based on
the idea that the shapes of the auditory weighting functions and TTS/
PTS exposure thresholds are directly related to the audiograms; i.e.,
that changes to the composite audiograms would directly influence the
TTS/PTS exposure functions (e.g., Wright (2015) describes weighting
functions as ``effectively the mirror image of an audiogram'' (p. 2)
and states, ``The underlying goal was to estimate how much a sound
level needs to be above hearing threshold to induce TTS.'' (p. 3)).
Both statements are incorrect and suggest a fundamental
misunderstanding of the criteria/threshold derivation. This would
require a constant (frequency-independent) relationship between hearing
threshold and TTS onset that is not reflected in the actual marine
mammal TTS data. Attempts to create a ``cautionary'' outcome by
artificially lowering the composite audiogram thresholds would not
necessarily result in lower TTS/PTS exposure levels, since the exposure
functions are to a large extent based on applying mathematical
functions to fit the existing TTS data.
Comment 4: A Commenter recommended that NMFS specify in the
preamble to the final rule whether the data regarding behavioral
audiograms (Branstetter et al. 2017, Kastelein et al. 2017b) and TTS
(Kastelein et al. 2017a and c, Popov et al. 2017, Kastelein et al.
2018a and 2019a and b) support the continued use of the current
weighting functions and PTS and TTS thresholds.
Response: Thus far, no new information has been published or
otherwise conveyed that would fundamentally change the assessment of
impacts or conclusions of this rule regarding current weighting
functions and PTS and TTS thresholds. Furthermore, the recent peer-
reviewed updated marine mammal noise exposure criteria by Southall et
al. (2019a) provide identical PTS and TTS thresholds to those provided
in NMFS' Acoustic Technical Guidance. NMFS' Revised Technical Guidance
for Assessing the Effects of Anthropogenic Sound on Marine Mammal
Hearing (NMFS 2018) (Acoustic Technical Guidance), which was used in
the assessment of effects for this rulemaking, compiled, interpreted,
and synthesized the best available scientific information for noise-
induced hearing effects for marine mammals to derive updated thresholds
for assessing the impacts of noise on marine mammal hearing, including
the articles that the Commenter referenced that were published
subsequent to the publication of the first version of the Acoustic
Technical Guidance in 2016. The new data included in those articles are
consistent with the thresholds and weighting functions included in the
current version of the Acoustic Technical Guidance (NMFS, 2018). NMFS
will continue to review and evaluate new relevant data as it becomes
available and consider the impacts of those studies on the Acoustic
Technical Guidance to determine what revisions/updates may be
appropriate.
Comment 5: Commenters recommended that NMFS refrain from using cut-
off distances in conjunction with the Bayesian Behavioral Response
Functions (BRFs) and re-estimate the numbers of marine mammal takes
based solely on the Bayesian BRFs as the use of cut-off distances could
be perceived as an attempt to reduce the numbers of takes.
Response: The consideration of proximity (cut-off distances) was
part of the criteria developed in consultation between the Navy and
NMFS, and is appropriate based on the best available science which
shows that marine mammal responses to sound vary based on both sound
level and distance. Therefore these cut-off distances were applied
within the Navy's acoustic effects model. The derivation of the
behavioral response functions and associated cut-off distances is
provided in the 2017 technical report titled ``Criteria and Thresholds
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)''. To
account for non-applicable contextual factors, all available data on
marine mammal reactions to actual Navy activities and other sound
sources (or other large scale activities such as seismic surveys when
information on proximity to sonar sources was not available for a given
species group) were reviewed to find the farthest distance to which
significant behavioral reactions were observed. These distances were
rounded up to the nearest 5 or 10 km interval, and for moderate to
large scale activities using multiple or louder sonar sources, these
distances were greatly increased--doubled in most cases. The Navy's
BRFs applied within these distances provide technically sound methods
reflective of the best available science to estimate the impact and
potential take for the actions analyzed within the 2020 MITT FSEIS/OEIS
and included in these regulations. NMFS has independently assessed the
Navy's behavioral harassment thresholds (i.e., their BRFs) and finds
that they appropriately apply the best available science and it is not
necessary to recalculate take estimates.
The Commenters also specifically expressed concern that distance
``cut-offs'' alleviate some of the exposures that would otherwise have
been counted if the received level alone were considered. It is unclear
why the Commenters find this inherently inappropriate, as this is what
the data show. As noted previously, there are multiple studies
illustrating that in situations where one would expect behavioral
disturbance of a certain degree because of the received levels at which
previous responses were observed, it has not occurred when the distance
from the source was larger than the distance of the first observed
response.
Comment 6: Regarding the behavioral harassment thresholds for
explosives, Commenters recommended that NMFS estimate and ultimately
authorize takes of marine mammals by Level B harassment in the form of
behavioral disturbance, as well as TTS, during all explosive
activities, including those that involve single detonations.
Response: The derivation of the explosive injury criteria is
provided in the 2017 technical report titled ``Criteria and Thresholds
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III),''
and NMFS has applied the general rule a commenter referenced to single
explosives for years, i.e., that marine mammals are unlikely to respond
to a single instantaneous detonation at received levels below the TTS
threshold in a manner that would rise to the level of a take. Neither
NMFS nor the Navy are aware of evidence to support the assertion that
animals will have significant behavioral reactions (i.e., those that
would rise to the level of a take) to temporally and spatially isolated
explosions at received levels below the TTS threshold.
Marine mammals may be exposed to isolated impulses in their natural
environment (e.g., lightning). There is no evidence to support that
animals have significant behavioral responses to temporally and
spatially isolated impulses (such as military explosions) that may rise
to the level of ``harassment'' under the MMPA for military readiness
activities. Still, the analysis conservatively assumes that any modeled
instance of temporally or spatially separated detonations occurring in
a single 24-hour period would result in harassment under the
[[Page 46316]]
MMPA for military readiness activities. The Navy has been monitoring
detonations since the 1990s and has not observed these types of
reactions. To be clear, this monitoring has occurred under the
monitoring plans developed specifically for shock trials, the
detonations with the largest net explosive weight conducted by the
Navy, and no shock trials are proposed in this study area.
Further, to clarify, the current take estimate framework does not
preclude the consideration of animals being behaviorally disturbed
during single explosions as they are counted as ``taken by Level B
harassment'' if they are exposed above the TTS threshold, which is only
5 dB higher than the behavioral harassment threshold. We acknowledge in
our analysis that individuals exposed above the TTS threshold may also
be behaviorally disturbed and those potential impacts are considered in
the negligible impact determination.
Comment 7: A Commenter stated that the behavioral response
functions rely on captive animal studies and the risk functions do not
incorporate a number of relevant studies on wild marine mammals
(specifically referencing a passive acoustic study on blue whales). The
Commenter asserts it is not clear from the proposed rule, or from the
Navy's recent technical report on acoustic ``criteria and thresholds,''
on which NMFS' approach here is based, exactly how each of the studies
that NMFS employed was applied in the analysis, or how the functions
were fitted to the data, but the available evidence on behavioral
response raises serious concerns that the functions are not
conservative for some species. For this reason and others, and given
the obvious importance of this analysis for future acoustic impact
analyses, the Commenter requests that NMFS make additional technical
information available, including from any expert elicitation and peer
review, and to re-open public comment on this issue.
Response: We refer the Commenter to the Criteria and Thresholds for
the U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)
Technical Report (U.S. Department of the Navy, 2017) for details on how
the Navy accounted for the differences in captive and wild animals in
the development of the behavioral response risk functions, which NMFS
has evaluated and deemed appropriate to incorporate into the analysis
in the rule. The appendices to this report detail the specific data
points used to generate the behavioral response functions. Data points
come from published data that is readily available and cited within the
technical report, and NMFS disagrees that it is necessary to re-open
public comment on this issue.
The Navy uses the best available science in the analysis, which has
been reviewed by external scientists and approved by NMFS. The Navy
considered all data available at the time for the development of
updated criteria and thresholds, and limiting the data to the small
number of field studies would not provide enough data with which to
develop the new risk functions. In addition, the Navy accounts for the
fact that captive animals may be less sensitive, and the scale at which
a moderate-to-severe response was considered to have occurred is
different for captive animals than for wild animals, as the Navy
understands those responses will be different. The new risk functions
were developed in 2016, before several recent papers were published or
the data were available. The Navy and NMFS continue to evaluate the
information as new science is made available. The criteria have been
rigorously vetted within the Navy community, among scientists during
expert elicitation, and then reviewed by the public before being
applied. It is unreasonable to revise and update the criteria and risk
functions every time a new paper is published. NMFS concurs with the
Navy's evaluation and conclusion that there is no new information that
necessitates changing the acoustic thresholds at this time.
These new papers provide additional information, and the Navy is
considering them for updates to the criteria in the future, when the
next round of updated criteria will be developed. Regarding
consideration of research findings involving a passive acoustic study
on blue whale vocalizations and behavior, the Navy considered multiple
recent references, including but not limited to: Paniagua-Mendoza,
2017; Lesage, 2017; DeRuiter, 2017; Mate, 2016; Lomac-MacNair, 2016;
Friedlaender, 2016; Mate, 2015. Thus far, no new information has been
published or otherwise conveyed that would fundamentally change the
assessment of impacts or conclusions of this Supplemental EIS/OEIS. To
be included in the BRF, data sets needed to relate known or estimable
received levels to observations of individual or group behavior. Melcon
et al. (2012) does not relate observations of individual/group behavior
to known or estimable received levels at that individual/group. In
Melcon et al. (2012), received levels at the HARP buoy averaged over
many hours are related to probabilities of D-calls, but the received
level at the blue whale individuals/group are unknown.
Comment 8: A Commenter commented that dipping sonar, like hull-
mounted sonar, appears to be a significant predictor of deep-dive rates
in beaked whales, with the dive rate falling significantly (e.g., to 35
percent of that individual's control rate) during sonar exposure, and
likewise appears associated with habitat abandonment. According to the
Commenter, the data sources used to produce the Navy's behavioral
response functions (BRF) concern hull-mounted sonar, an R/V-deployed
sonar playback, or an in-pool source. The Navy's generic behavioral
response function for beaked whales does not incorporate their
heightened response to these sources, although such a response would be
presumed to shift its risk function ``leftward.'' Nor do the response
functions for other species account for this difference, although
unpredictability is known to exacerbate stress response in a diversity
of mammalian species and should conservatively be assumed, in this
case, to lead to a heightened response in marine mammal species other
than beaked whales.
Response: In consultation with NMFS, the Navy relied upon the best
science that was available to develop the behavioral response
functions. The current beaked whale BRF acknowledges and incorporates
the increased sensitivity observed in beaked whales during both
behavioral response studies and during actual Navy training events, as
well as the fact that dipping sonar can have greater effects than some
other sources with the same source level. Specifically, the distance
cut-off for beaked whales is 50 km, larger than any other group.
Moreover, although dipping sonar has a significantly lower source level
than hull-mounted sonar, it is included in the category of sources with
larger distance cut-offs, specifically in acknowledgement of its
unpredictability and association with observed effects. This means that
``takes'' are reflected at lower received levels that would have been
excluded because of the distance for other source types.
An article referenced by the Commenter (Associating patterns in
movement and diving behavior with sonar use during military training
exercises: A case study using satellite tag data from Cuvier's beaked
whales at the Southern California Anti-submarine Warfare Range (Falcone
et al., 2017)) was not available at the time the BRFs were developed.
However, NMFS and the Navy have reviewed the article and concur that
neither this article nor any
[[Page 46317]]
other new information that has been published or otherwise conveyed
since the proposed rule was published changes the assessment of impacts
or conclusions in the 2020 MITT FSEIS/OEIS or in this rulemaking.
Additionally, the Navy's current beaked whale BRF covers the responses
observed in this study since the beaked whale risk function is more
sensitive than the other risk functions at lower received levels. The
researchers involved with the study are still refining their analytical
approach and integrating additional statistical parameters for future
reporting. Nonetheless, the new information and data presented in the
article were thoroughly reviewed by the Navy and will be quantitatively
incorporated into future behavioral response functions, as appropriate,
when and if other new data that would meaningfully change the functions
would necessitate their revision.
Furthermore, ongoing Navy funded beaked whale monitoring at the
same site where the dipping sonar tests were conducted has not
documented habitat abandonment by beaked whales. Passive acoustic
detections of beaked whales have not significantly changed over ten
years of monitoring (DiMarzio et al., 2018, updated in 2020). From
visual surveys in the area since 2006 there have been repeated
sightings of: The same individual beaked whales, beaked whale mother-
calf pairs, and beaked whale mother-calf pairs with mothers on their
second calf (Schorr et al., 2018, 2020). Satellite tracking studies of
beaked whales documented high site fidelity to this area (Schorr et
al., 2018, updated in 2020).
Comment 9: A Commenter recommends that NMFS (1) explain why, if the
constants and exponents for onset mortality and onset slight lung
injury thresholds for the current phase of incidental take rulemaking
for the Navy (Phase III) have been amended to account for lung
compression with depth, they result in lower rather than higher
absolute thresholds when animals occur at depths greater than 8 m and
(2) specify what additional assumptions were made to explain this
counterintuitive result.
Response: The derivation of the explosive injury equations,
including any assumptions, is provided in the 2017 technical report
titled ``Criteria and Thresholds for U.S. Navy Acoustic and Explosive
Effects Analysis (Phase III).'' Specifically, the equations were
modified in Phase III to fully incorporate the injury model in Goertner
(1982), specifically to include lung compression with depth. NMFS
independently reviewed and concurred with this approach.
The impulse mortality/injury equations are depth dependent, with
thresholds increasing with depth due to increasing hydrostatic pressure
in the model for both the previous 2015-2020 phase of rulemaking (Phase
II) and Phase III. The underlying experimental data used in Phase II
and Phase III remain the same, and two aspects of the Phase III
revisions explain the relationships the Commenter notes:
(1) The numeric coefficients in the equations are computed by
inserting the Richmond et al. (1973) experimental data into the model
equations. Because the Phase III model equation accounts for lung
compression, the plugging of experimental exposure values into a
different model results in different coefficients. The numeric
coefficients are slightly larger in Phase III versus Phase II,
resulting in a slightly greater threshold near the surface.
(2) The rate of increase for the Phase II thresholds with depth is
greater than the rate of increase for Phase III thresholds with depth
because the Phase III equations take into account the corresponding
reduction in lung size with depth (making an animal more vulnerable to
injury per the Goertner model), as the Commenter notes.
Ranges to effect are based on these injury thresholds, in addition
to geometry of exposure (location of an animal relative to the
explosive charge, horizontally and vertically), propagation
environment, and the impulse integration duration.
Comment 10: A Commenter recommends that NMFS use onset mortality,
onset slight lung injury, and onset GI tract injury thresholds rather
than the 50-percent thresholds to estimate both the numbers of marine
mammal takes and the respective ranges to effect. If NMFS does not
implement the recommendation, the Commenter further recommends that
NMFS (1) specify why it is inconsistently basing its explosive
thresholds for Level A harassment on onset of PTS and Level B
harassment on onset of TTS and onset of behavioral response, while the
explosive thresholds for mortality and Level A harassment are based on
the 50-percent criteria for mortality, slight lung injury, and GI tract
injury, (2) provide scientific justification supporting that slight
lung and GI tract injuries are less severe than PTS and thus the 50-
percent rather than onset criteria are more appropriate for estimating
Level A harassment for those types of injuries, and (3) justify why the
number of estimated mortalities should be predicated on at least 50
percent rather than 1 percent of the animals dying.
Response: As appropriate, NMFS and the Navy have used a combination
of exposure thresholds and consideration of mitigation to inform the
take estimates. The Navy used the range to one percent risk of
mortality and injury (referred to as ``onset'' in the 2020 MITT FSEIS/
OEIS) to inform the development of mitigation zones for explosives.
Ranges to effect based on one percent risk criteria were examined to
ensure that explosive mitigation zones would encompass the range to any
potential mortality or non-auditory injury, affording actual protection
against these effects. In all cases, the mitigation zones for
explosives extend beyond the range to one percent risk of non-auditory
injury, even for a small animal (representative mass = 5 kg).
Given the implementation and expected effectiveness of this
mitigation, the application of the indicated threshold is appropriate
for the purposes of estimating take. Using the 1 percent non-auditory
injury risk criteria to estimate take would result in an over-estimate
of take, and would not afford extra protection to any animal.
Specifically, calculating take based on marine mammal density within
the area that an animal might be exposed above the 1 percent risk
criteria would over-predict effects because many of those exposures
will not happen because of the effective mitigation. The Navy, in
coordination with NMFS, has determined that the 50 percent incidence of
occurrence is a reasonable representation of a potential effect and
appropriate for take estimation, given the mitigation requirements at
the 1 percent threshold, and the area ensonified above this threshold
would capture the appropriate reduced number of likely injuries.
Although the commenter implies that the Navy did not use extensive
lung hemorrhage as indicative of mortality, that statement is
incorrect. Extensive lung hemorrhage is assumed to result in mortality,
and the explosive mortality criteria are based on extensive lung injury
data. See the 2017 technical report titled ``Criteria and Thresholds
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III).''
Comment 11: A Commenter stated that NMFS, following the Navy, has
applied a post-modeling adjustment to its estimate of lethal take that
substantially reduces the total number. That adjustment, in the case of
serious injury and mortality, purports to account for the effectiveness
of visual observers in detecting marine mammals within the blast zone
of an underwater
[[Page 46318]]
explosion (or within the radius of permanent acoustic injury), but
NMFS' borrowed methods here are non-transparent and misconceived. The
Navy's DSEIS/OEIS for the MITT Study Area starts with the species-
specific g(0) factors applied in professional marine mammal abundance
surveys (the probability that an object that is on the line is detected
using standard line-transect methods), then multiplies them by simple
factors to reflect the relative effectiveness of its Lookouts in
routine operating conditions. Yet the Navy's sighting effectiveness is
likely to be much poorer than that of experienced biologists dedicated
exclusively to marine mammal detection, operating under conditions that
maximize sightings. In any case, the public has no meaningful way to
further evaluate the agencies' adjustment since the proposed rule does
not provide the scores used to generate the effectiveness factor or the
agencies' pre-adjustment take numbers, nor does the Navy in the
ancillary report NMFS references. The Commenter suggests that ``[s]ince
the Navy has yet to determine the effectiveness of its mitigation
measures, it is premature to include any related assumptions to reduce
the numbers of marine mammal takes.'' Another Commenter recommends that
NMFS (1) specify the total numbers of model estimated Level A
harassment (PTS) and mortality takes rather than reduce the estimated
numbers of takes based on the Navy's post-model analyses and (2)
include the model-estimated Level A harassment and mortality takes in
its negligible impact determination analyses.
Response: The consideration of marine mammal avoidance and
mitigation effectiveness is integral to NMFS' and the Navy's overall
analysis of impacts from sonar and explosive sources. NMFS has
independently evaluated the method and agrees that it is appropriately
applied to augment the model in the prediction and authorization of
injury and mortality as described in the rule. Details of this analysis
are provided in the Navy's 2018 technical report titled ``Quantifying
Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and
Analytical Approach for Phase III Training and Testing.'' Additional
information on the mitigation analysis also was included in the
proposed rule and NMFS disagrees with the Commenter's suggestion that
there was not enough information by which to evaluate the Navy's post-
modeling calculations. Also, it should be noted that even before
consideration of mitigation effectiveness, there were no modeled
mortalities to any marine mammals.
Sound levels diminish quickly below levels that could cause PTS.
Specifically, behavioral response literature, including the recent 3S
and SOCAL BRS studies, indicate that multiple species from different
cetacean suborders do in fact avoid approaching sound sources by a few
hundred meters or more, which would reduce received sound levels for
individual marine mammals to levels below those that could cause PTS
(see Appendix B of the ``Criteria and Thresholds for U.S. Navy Acoustic
and Explosive Impacts to Marine Mammals and Sea Turtles Technical
Report'' (U.S. Department of the Navy, 2017) and Southall et al.
(2019a)). The ranges to PTS for most marine mammal groups are within a
few tens of meters and the ranges for the most sensitive group, the HF
cetaceans, average about 200 m, to a maximum of 270 m in limited cases.
For blue whales and other LF cetaceans, the range to PTS is 65 m for
MF1 30 sec duration exposure, which is well within the mitigation zones
for hull-mounted MFAS. Therefore, the anticipated avoidance to the
distances discussed would greatly reduce the likelihood of impacts to
hearing such as TTS and PTS. As discussed in the Navy's report, animats
in the Navy's acoustic effects model do not move horizontally or
``react'' to sound in any way. Accordingly, NMFS and the Navy's
analysis appropriately applies a quantitative adjustment to the
exposure results calculated by the model (which does not consider
avoidance or mitigation).
As discussed in the Navy's report, the Navy's acoustic effects
model does not consider procedural mitigations (i.e., power-down or
shut-down of sonars, or pausing explosive activities when animals are
detected in specific zones adjacent to the source), which necessitates
consideration of these factors in the Navy's overall acoustic analysis.
Credit taken for mitigation effectiveness is extremely conservative.
For example, if Lookouts can see the whole area, they get credit for it
in the calculation; if they can see more than half the area, they get
half credit; if they can see less than half the area, they get no
credit. Not considering animal avoidance and mitigation effectiveness
would lead to a great overestimate of injurious impacts. NMFS concurs
with the analytical approach used, i.e., we believe the estimated take
by Level A harassment numbers represent the maximum number of these
takes that are likely to occur and it would not be appropriate to
authorize a higher number or consider a higher number in the negligible
impact analysis.
The Navy assumes that Lookouts will not be 100 percent effective at
detecting all individual marine mammals within the mitigation zones for
each activity. This is due to the inherent limitations of observing
marine species and because the likelihood of sighting individual
animals is largely dependent on observation conditions (e.g., time of
day, sea state, mitigation zone size, observation platform) and animal
behavior (e.g., the amount of time an animal spends at the surface of
the water). The Navy quantitatively assessed the effectiveness of its
mitigation measures on a per-scenario basis for four factors: (1)
Species sightability, (2) a Lookout's ability to observe the range to
permanent threshold shift (for sonar and other transducers) and range
to mortality (for explosives), (3) the portion of time when mitigation
could potentially be conducted during periods of reduced daytime
visibility (to include inclement weather and high sea-state) and the
portion of time when mitigation could potentially be conducted at
night, and (4) the ability for sound sources to be positively
controlled (e.g., powered down). The Navy's report clearly describes
how these factors were considered, and it is not necessary to view the
many tables of numbers generated in the assessment to evaluate the
method.
The g(0) values used by the Navy for their mitigation effectiveness
adjustments take into account the differences in sightability with sea
state, and utilize averaged g(0) values for sea states of 1-4 and
weighted as suggested by Barlow (2015). Using g(0) values is an
appropriate and conservative approach (i.e., underestimates the
protection afforded by the Navy's mitigation measures) for the reasons
detailed in the technical report. For example, during line-transect
surveys, there are typically two primary observers searching for
animals. Each primary observer looks for marine species in the forward
90-degree quadrant on their side of the survey platform and scans the
water from the vessel out to the limit of the available optics (i.e.,
the horizon). Because Navy Lookouts focus their observations on
established mitigation zones, their area of observation is typically
much smaller than that observed during line-transect surveys. The
mitigation zone size and distance to the observation platform varies by
Navy activity. For example, during hull-mounted mid-frequency active
sonar activities, the mitigation zone extends 1,000 yd from the ship
[[Page 46319]]
hull. During the conduct of training and testing activities, there is
typically at least one, if not numerous, support personnel involved in
the activity (e.g., range support personnel aboard a torpedo retrieval
boat or support aircraft). In addition to the Lookout posted for the
purpose of mitigation, these additional personnel observe for and
disseminate marine species sighting information amongst the units
participating in the activity whenever possible as they conduct their
primary mission responsibilities. However, as a conservative approach
to assigning mitigation effectiveness factors, the Navy elected to
account only for the minimum number of required Lookouts used for each
activity; therefore, the mitigation effectiveness factors may
underestimate the likelihood that some marine mammals may be detected
during activities that are supported by additional personnel who may
also be observing the mitigation zone.
Although NAEMO predicted PTS, no mortality or non-auditory injury
were predicted by NAEMO. Of these two non-auditory effects (mortality
and non-auditory injury), only mortality would have been subject to
mitigation consideration in the quantitative analysis, if there had
been any. Also, as discussed in Comment 43, the Navy will be providing
NMFS with a report summarizing the status of and/or providing its final
assessment on the Navy's Lookout Effectiveness Study following the end
of CY 2021.
Comment 12: One Commenter asserted that NMFS and the Navy make
certain post-modeling adjustments to their estimates of non-lethal
injury, on flawed assumptions about animal avoidance and mitigation
effectiveness. A Commenter stated in regards to the method by which the
Navy's post-model calculation considers avoidance specifically (i.e.,
assuming animals present beyond the range of PTS for the first few
pings will be able to avoid it and incur only TTS, which results in a
95 percent reduction in the number of estimated PTS takes predicted by
the model), given that sound sources are moving, it may not be until
later in an exercise that the animal is close enough to experience PTS,
and it is those few close pings that contribute to the potential to
experience PTS. Marine mammals may remain in important habitat, and the
most vulnerable individuals may linger in an area, notwithstanding the
risk of harm; marine mammals cannot necessarily predict where an
exercise will travel. In addition, Navy vessels may move faster than
the ability of the animals to evacuate the area. The Commenter
expressed concern that this method underestimates the number of PTS
takes and that NMFS should not create an under-supported,
nonconservative adjustment for avoidance. The Commenter further
suggested that the Navy could query the dosimeters on the animats in
its model to test its assumption.
Response: The consideration of marine mammals avoiding the area
immediately around the sound source is provided in the Navy's 2018
technical report titled ``Quantitative Analysis for Estimating Acoustic
and Explosive Impacts to Marine Mammals and Sea Turtles.'' As the
Commenter correctly articulates: ``For avoidance, the Navy assumed that
animals present beyond the range to onset PTS for the first three to
four pings are assumed to avoid any additional exposures at levels that
could cause PTS. That equated to approximately 5 percent of the total
pings or 5 percent of the overall time active; therefore, 95 percent of
marine mammals predicted to experience PTS due to sonar and other
transducers were instead assumed to experience TTS.''
In regard to the comment about vessels moving faster than animals'
ability to get out of the way, as discussed in the Navy's 2018
technical report titled ``Quantitative Analysis for Estimating Acoustic
and Explosive Impacts to Marine Mammals and Sea Turtles,'' animats in
the Navy's acoustic effects model do not move horizontally or ``react''
to sound in any way, necessitating the additional step of considering
animal avoidance of close-in PTS zones. NMFS independently reviewed
these assumptions and this approach and concurs that they are fully
supported by the best available science. Based on a growing body of
behavioral response research, animals do in fact avoid the immediate
area around sound sources to a distance of a few hundred meters or more
depending upon the species. Avoidance to this distance greatly reduces
the likelihood of impacts to hearing such as TTS and PTS, respectively.
Specifically, the ranges to PTS for most marine mammal groups are
within a few tens of meters and the ranges for the most sensitive
group, the HF cetaceans, average about 200 m, to a maximum of 270 m in
limited cases. The Commenter's point about speed is not applicable to
the initially distant animals that are discounted by this method, most
of which would be able to avoid the source as there is more time
(because they are farther from the source) to do so. Further, the
Commenter ignores the corollary to their point, which is that given the
speed the Navy vessels operating sonar are typically traveling relative
to the speed and direction of marine mammals, the likelihood of
individuals remaining in close enough proximity to the source for a
duration that would result in TTS or PTS is lessened.
Querying the dosimeters of the animats would not produce useful
information since, as discussed previously, the animats do not move in
the horizontal and are not programmed to ``react'' to sound or any
other stimulus.
Humpback Whales
Comment 13: Commenters assert that the proposed reporting
requirement for MF1 MFAS (with the lack of any restriction on actual
sonar use) in the Chalan Kanoa Reef and Marpi Reef Geographic
Mitigation Areas would not protect humpback whales, and particularly
calves during this sensitive life stage. Further, the Commenters note
that because these areas have not been a high[hyphen]use area for the
Navy and ASW training events and are ``considered generally unsuitable
for training needs,'' (85 FR 48388), there is no justification for
failing to prohibit sonar use in this sensitive humpback whale habitat
off Saipan. One Commenter recommended that NMFS prohibit use of MF1
sonar in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
Areas during the months that humpbacks are present in the Marianas
while another suggested a year-round prohibition.
Response: Following extensive discussions with the Navy during
which more specific granular information about the Navy's likely
activity was provided and the practicability of additional restrictions
were considered, new information about humpback whale occurrence in the
mitigation areas emerged, and new analyses were conducted (see the
Estimated Take of Marine Mammals section), NMFS established a 20-hr
annual cap from December 1-April 30 on the use of hull-mounted MF1 MFAS
for these two Geographic Mitigation Areas (20 hrs total for both areas
combined) to minimize sonar exposure and reduce the amount and/or
severity of take by Level B harassment (behavioral disturbance and/or
TTS) of humpback whales in these important reproductive areas. It is
important to note that in the Navy's rulemaking/LOA application and
NMFS' associated analysis for the proposed rule, while high amounts of
sonar training may not have been expected, the amount of sonar use in
these areas had not been limited.
Our evaluation of potential mitigation measures includes
consideration of both
[[Page 46320]]
(1) the manner in which, and the degree to which, implementation of the
potential measure(s) is expected to reduce adverse impacts to marine
mammal species or stocks and their habitat and (2) the practicability
of the measures for applicant implementation, which in this case
includes the impact on the Navy's military readiness activities. While
we did consider completely restricting MF1 MFAS in the two Geographic
Mitigation Areas, we also considered the Navy's broader need for
flexibility as well as the specific need not to restrict these shallow-
water training areas entirely in the MITT Study Area given the
proximity to forward deployed operations and the higher likelihood of a
need to have the option to conduct training quickly to respond to
emergent national security threats. The Navy expects current and future
use of the two Geographic Mitigation Areas to remain low, but the 20-hr
cap will allow the Navy flexibility to engage in a small amount of
necessary training, most likely such as a Small Coordinated ASW
Exercise or TRACKEX event(s), which could occur up to five days, but no
more than four hours per day (or similar configuration totalling no
more than 20 hrs). Areas of shallow depths are limited in the Mariana
Archipelago, and NMFS determined (with the Navy's input) that it would
be impracticable to completely limit the use of sonar at the Chalan
Kanoa Reef and Marpi Reef due to the requirement to have access to such
bathymetry for training purposes in order to support mission
requirements as established by operational Commanders. The reduction in
potential exposure of humpback whales to sonar in these areas and at
this time (i.e., the short overall and daily exposure) would reduce the
likelihood of impacts that could affect reproduction or survival, by
minimizing impacts on calves during this sensitive life stage, avoiding
the additional energetic costs to mothers of avoiding the area and
minimizing the chances that important behaviors (e.g., cow-calf
communication, breeding behaviors) are interrupted to the point that
survivorship or reproduction are impacted. Therefore, we have
determined that the 20-hr cap on MF1 MFAS sonar in the two Geographic
Mitigation Areas will meaningfully reduce impacts on the affected
humpback whales and, further, be practicable for Navy implementation.
As an additional measure, the Navy will also now report all active
sonar use (all bins, by bin) in these areas between December 1 and
April 30 to NMFS in their annual reports. This will allow NMFS to
evaluate the sonar use in the two Geographic Mitigation Areas over the
seven-year period and to determine if further mitigation is warranted.
Comment 14: A Commenter recommended a prohibition on mid-frequency
air deployed dipping sonar, year-round in the Geographic Mitigation
Areas. The Commenter also commented that dipping sonar has been shown
to have disproportionate impacts on beaked whales and may impact other
species such as humpback whales in a similar manner, due to the
unpredictability of the signal.
Response: Regarding the applicability of the data the Commenter
cites to humpback whale responses, the research was focused exclusively
on beaked whales and, further, in regard to the data cited, certain
limitations are still under investigation such as the proximity of the
source and other factors. Behavioral responses of beaked whales from
dipping and other sonars cannot be universally applied to other marine
mammal species, especially since beaked whales are known to be more
sensitive to lower level sounds, which is reflected in our analysis
through a lower behavioral harassment threshold. For example, Navy-
funded behavioral response studies of blue whales to simulated surface
ship sonar have demonstrated there are distinct individual variations
as well as strong behavioral state considerations that influence any
response or lack of response. The majority of take by Level B
harassment results from MF1 sonar, which is practicable to limit in the
Chalan Kanoa Reef and Marpi Reef Geographic Mitigation Areas. Sonar
activities in this area have been limited historically, there is
insufficient evidence to suggest that MF4 sonar would have
disproportionately adverse effects, and further limitation of MF4
dipping sonar use in these areas would not be expected to meaningfully
reduce impacts to humpback whales.
With regards to beaked whales, water depths in the Chalan Kanoa
Reef and Marpi Reef Geographic Mitigation Areas are not suitable
habitats for beaked whales. There is no evidence to suggest that
prohibiting the use of mid-frequency dipping sonar in the Geographic
Mitigation Areas would have any benefit to beaked whales.
Comment 15: A Commenter recommended prohibiting use of low-
frequency active sonar from December through April in the Marpi Reef
and Chalan Kanoa Reef Geographic Mitigation Areas, because they assert
that baleen whales are vulnerable to the impacts of low-frequency
active sonar, particularly in calving areas where low-amplitude
communication calls between mothers and calves can be easily masked.
Response: Low-frequency sonar use in this rule has been
significantly scaled down from previous authorizations. The Navy is
only seeking authorization for 11 hrs or less per year of low-frequency
sonar use in the MITT Study Area, with most of these systems used
further offshore. Furthermore, the most used source at approximately 10
hrs (LF5) has source levels less than 180 dB and one hour of LF4 with
source levels greater than 180 dB and less than or equal to 200 dB,
with the associated harassment zones significantly smaller than for
MF1. Based on historical sonar use in the MITT Study Area, it is highly
unlikely that the few planned low-frequency sonar hours would occur in
the Geographic Mitigation Areas from December through April. Given
that, and the smaller impact zones, a prohibition would have very
limited or no potential benefit to humpback whales and other baleen
whales and would unnecessarily impose a restriction on training and
testing in the MITT Study Area.
Comment 16: A Commenter recommended extending the Marpi Reef
Geographic Mitigation Area boundaries to include a buffer that
encompasses the humpback whale sightings data beyond the 400-m depth
contour and the southernmost point of the proposed Marpi Reef
Geographic Mitigation Area.
Response: NMFS extended the boundary out to the 400-m isobath for
both Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas prior
to the publication of the proposed rule. NMFS and the Navy considered
using bathymetry to define the Marpi Reef Geographic Mitigation Area
when initially evaluating potential mitigation areas, but instead
relied on confirmed sightings of humpback whales to define the area.
After reviewing the detailed bathymetry of the reef coupled with marine
mammal sightings, NMFS and the Navy reevaluated how the Marpi Reef
Geographic Mitigation Area was bounded and redefined the area based on
the extent of the 400-m isobath. Given most sightings of humpback
whales were in waters less than 200 m in depth, this provides an
additional buffer between most sighting locations and the boundary for
the area. Seafloor areas extending beyond the reef are not necessarily
areas of potential biological importance (i.e., whales may have been
transiting to or from the reef when sighted). Scientists from NMFS'
Pacific Islands Fisheries Science Center, who have conducted numerous
humpback
[[Page 46321]]
whale surveys in Hawaii and the Mariana Islands, have observed that the
majority of humpback whale breeding activity (mother-calf pairs,
competitive behavior) happens in water depths of 200 m or less, with
more mother-calf pairs in water depths 50 m or less (Hill et al.,
2020). In addition, during a review of the Marpi Reef sightings and
bathymetry, the Navy found that the mitigation graphics in Appendix I
(Geographic Mitigation Assessment) of the 2020 MITT FSEIS/OEIS had
errors where bathymetric lines plotted were incorrectly shifted. This
issue was fixed using a more accurate small-scale bathymetric dataset.
Revised figures for the 2020 MITT FSEIS/OEIS show that all humpback
whale sightings near Marpi Reef where suspected reproductive behaviors
were observed (mother-calf pairs, competitive behavior) were shallower
than the 200-m isobath.
Comment 17: A Commenter recommends implementing vessel speed
restrictions from December through April in the Marpi Reef and Chalan
Kanoa Reef Geographic Mitigation Areas as they argue that ship strike
and vessel noise pose a serious risk to humpback whales, particularly
in calving and breeding areas. They say it is important that NMFS
prescribe vessel speed limits in this important breeding habitat and
that mandatory speed limits, such as those that NMFS has put in place
to protect North Atlantic right whales, have proven effective. NMFS has
no basis on which to determine that its ``notification message''
measure--which would depend on non-specialist, non-dedicated Navy
observers operating effectively in unfavorable sea states--would be as
effective, or effective at all. The Commenter states there is no reason
why NMFS cannot reasonably accommodate national security needs to
create exceptions to the rule if needed.
Response: To avoid physical disturbance and strike from vessel
movements, the Navy maneuvers to maintain a 500 yd mitigation zone from
whales and other marine mammals (except bow-riding dolphins). As
further described in Section 5.3.4.1 (Vessel Movement) of the 2020 MITT
FSEIS/OEIS implementing mitigation to limit vessel speeds in the MITT
Study Area would be incompatible with the Navy's criteria for safety,
sustainability, and mission requirements. For example, Navy vessel
operators need to train to proficiently operate vessels as they would
during military missions and combat operations, including being able to
react to changing tactical situations and evaluate system capabilities.
Navy studies from other range complexes demonstrated that median speeds
near coasts are already low, varying from 5 to 12 knots. Furthermore,
given that there have been no vessel strikes involving humpback whales
or other marine mammals while Navy vessels conducted training and
testing activities in the MITT Study Area, implementing vessel speed
restrictions in the Geographic Mitigation Areas or other locations in
the Study Area would not be an effective mitigation measure because it
would not result in discernible avoidance or reduction of impacts.
Given the lack of meaningful reduction in impacts combined with the
impracticability of ship speed restrictions, NMFS has found that this
measure is not warranted and it is not required in this rule.
Serious Injury and Mortality, Beaked Whales
Comment 18: Commenters stated that NMFS underestimated serious
injury and mortality for beaked whales around the Mariana Islands,
ignored the best available scientific information, and failed to make
any meaningful assessment and negligible impact determination of the
likelihood that Navy training and testing activities triggered
strandings in the MITT Study Area. A Commenter stated that NMFS has
failed to demonstrate a rational basis for its assumption that ``[n]o
mortality or Level A harassment [of beaked whales] is expected'' from
MITT activities, rendering NMFS's preliminary determination of
negligible impact arbitrary and capricious. Another Commenter noted
that in the Guam press, at least six beaked whale stranding events,
each involving as many as three animals, have been reported in the
archipelago since 2006, as compared with only a single stranding in the
previous 35 years. That number of recent stranding events was
subsequently corrected to eight, in a paper that appeared earlier this
year in a major, peer-reviewed journal. The Simonis et al. (2020)
paper, whose co-authors include several NMFS biologists, correlated
four of these events with Navy operations, a correlation that it
describes as ``highly significant.'' The Commenter argued that the best
available science shows that serious injuries and mortalities are
likely to far exceed the number of reported strandings. Numerous
studies along multiple lines of evidence, including post-stranding
pathology, laboratory study of organ tissue, and theoretical work on
dive physiology, in addition to expert reviews, indicate that
behaviorally-mediated injury and mortality is occurring through
maladaptive alteration of the dive pattern in response to Navy sonar
exposure--impacts that occur at sea, independent of a whale's
stranding. The Commenter argues that in light of the available
scientific evidence, this position is both arbitrary and irresponsible.
They state that NMFS' method in the proposed rule is to cast doubt on
an undefined subset of previous stranding events on the grounds that
the precise mechanism of harm could not be established, even while
describing in detail the abundance of pathological and forensic
evidence.
In a related comment, another Commenter asserted that although NMFS
does not expect injury or mortality of any of beaked whales to occur as
a result of the Navy's active sonar training exercises, NMFS's
justification for authorizing beaked whale mortalities under Phase I
and the previous Phase II regulations is still valid. The Commenter
argues that NMFS cannot ignore that there remains the potential for the
operation of MFAS to contribute to the mortality of beaked whales.
Given that the potential for beaked whale mortalities cannot be
obviated, the Commenter recommends that NMFS authorize at least 10
mortality takes of beaked whales associated with MFA sonar use in the
MITT Study Area in the final rule.
Response: In the final rule, NMFS has included additional
information and analysis and expanded the explanation of why the best
available science does not indicate that the Navy's activities are
likely to result in mortality of beaked whales through stranding.
Please see the Stranding subsection of the Potential Effects of
Specified Activities on Marine Mammals and Their Habitat section, which
addresses the issues raised by the Commenters; comments not addressed
in that section are addressed below. To specifically correct an
inaccuracy in the Comment, it should be noted, that of the eight events
the Commenter refers to, only three had Navy sonar use before. Four
events cited in the paper was an error the authors acknowledged.
In regard to the authorization of mortality in MMPA regulations for
Phase I and II of MITT training and testing activities, the Commenter
is in error. Mortality was authorized in the Phase I MITT final rule,
in an abundance of caution given the events, worldwide, in which there
was a causal link between naval sonar and strandings, and noting that
there could be a stranding that co-occurred with Navy sonar that was
not caused by it. However, the rule explicitly stated that
[[Page 46322]]
``Neither NMFS nor the Navy anticipates that marine mammal strandings
or mortality will result from the use of mid- or high-frequency sonar
during Navy exercises within the MIRC Study Area.'' However, no
mortality was authorized in the Phase II final rule for the MITT Study
Area. The Navy initially requested mortality takes of beaked whales,
however, after further discussion of the lack of incidents in which
strandings were causally associated with sonar in the Marianas, or a
perceived reasonable likelihood that they would be at the time, NMFS
and the Navy determined that authorization of mortality was not
appropriate. NMFS does not argue that there is no possibility for
mortality to occur as a result of Navy activities, rather, we reason
that consideration of all applicable information (the best available
science) does not indicate that such mortality is reasonably likely to
result from the Navy's activities within the seven-year span of the
rule.
Comment 19: A Commenter stated that in addition to documenting the
substantial risk of injury and mortality to beaked whales from MITT
activities, Simonis et al. (2020) confirmed the existence of
biologically important areas for beaked whales near Saipan and Tinian.
The study found that at least three species of beaked whales--Cuvier's,
Blainville's, and a third unidentified species that may be the
ginkgo[hyphen]toothed beaked whale--occur in the Mariana Archipelago
throughout the year, similar to other island[hyphen]associated
populations around the world. The Commenter argues that before
finalizing its MMPA take regulations and issuing an LOA, NMFS must
fully evaluate this new scientific information, which supports the
establishment of a geographic mitigation area in the waters around
Saipan and Tinian to protect vulnerable beaked whales from Navy sonar.
Response: NMFS has evaluated the new scientific information from
Simonis et al. (2020) as well as years of field surveys conducted under
interagency agreements between the Navy and NMFS Pacific Islands
Fisheries Science Center and Navy-funded beaked whale monitoring, and
there remains a lack of scientific information available on beaked
whale distribution in the Marianas Islands. Simonis et al. (2020)
confirm that the acoustic record from their HARPs indicates that the
habitats near the recording locations are used by Blainville's,
Cuvier's and an unidentified beaked whale, however, they only suggest
that the locations ``may be considered as potentially important beaked
whale habitat,'' given that beaked whales were present a large portion
of the time at each recording site. Specifically, they note that the
presence of beaked whale signals in a recording can be indicative of
relative occurrence and seasonal fluctuations, however, given there are
only two recorders, the relative occurrence may only be compared
between the two locations, and the authors do not compare the
recordings to any other locations, making it impossible to draw
conclusions regarding how any inferred occurrence rates might compare
to other parts of the MITT Study Area or the species' range. The
information presented in Simonis et al. (2020), while informative, does
not provide sufficient information to warrant the addition of
geographic mitigation measures beyond the procedural mitigation
measures put in place through this final rule to reduce the number and
severity of takes for all marine mammals.
Without sufficient scientific data on beaked whale habitat use,
bathymetry, and seasonality, NMFS is unable to develop mitigation
measures that will meaningfully further reduce impacts to beaked whales
and not be impracticable for the Navy. That said, NMFS and the Navy are
committed to further actions (see the Changes from the Proposed Rule to
the Final Rule section) to expand the science and inform future
management actions related to beaked whales in the MITT Study Area. For
example, the Navy will co-fund the Pacific Marine Assessment Program
for Protected Species (PACMAPPS) survey in spring-summer 2021 to help
document beaked whale occurrence, abundance, and distribution in the
Mariana Islands. This effort will include deployments of a towed array
as well as floating passive acoustic buoys. The Navy will monitor
future beaked whale occurrence within select portions of the MITT Study
Area starting in 2022. Additionally, the Navy will include Cuvier's
beaked whales as a priority species for analysis under a 2020-2023
Navy-funded research program entitled Marine Species Monitoring for
Potential Consequences of Disturbance (MSM4PCOD). Finally, the Navy
will fund and co-organize with NMFS an expert panel to provide
recommendations on scientific data gaps and uncertainties for further
protective measure consideration to minimize the impact of Navy
training and testing activities on beaked whales in the Mariana
Islands.
Comment 20: One Commenter made several recommendations related to
NMFS' assessment and mitigation of beaked whale impacts. The Commenter
recommended that given beaked whales infrequent exposure to active
sonar in the MITT Study Area, more conservative behavioral response
curves be used to predict behavioral disturbance. The Commenter also
challenged NMFS' assertion that suitable alternative foraging habitat
is available for beaked whales in the MITT Study Area. Noting the
scarcity of beaked whale data, the Commenter recommended that acoustic
monitoring be implemented as the preferred method for estimating
density of beaked whales, instead of using Hawaii data and, further,
recommended more broadly that acoustic monitoring of beaked whales be
conducted to better understand the impacts of Navy activities on beaked
whales. The Commenter recommended that the Navy be more transparent in
their monitoring in sharing data indicating the timing of Navy
activities in relation to strandings. The Commenter noted that
additional personnel and support for local stranding response and
records is needed in order to better investigate causes of strandings
that coincide with Navy activities in the MITT Study Area. Last, the
Commenter notes that in order to detect any trend in the population,
there is a strong need to conduct consistent surveys, with adequate
methods for the species under consideration, over multiple years.
Response: Regarding the recommendation to modify the behavioral
harassment thresholds (specifically, lower the received levels at which
they would be considered taken) based on the infrequent exposures of
beaked whales to sonar in the Marianas, we first note that although the
amount of activities in the MITT Study Area is below the amount in the
AFTT or HSTT study areas, active sonar has been in regular use in the
MITT Study Area since the 1960s, and it is unlikely that marine mammals
in the area are naive to sonar exposure. Further, while NMFS
acknowledges the importance of context and considers it in evaluating
behavioral responses, there is not sufficient data upon which to base a
quantitative modification of the behavioral harassment thresholds.
Further, the behavioral thresholds for beaked whales are already lower
than for other taxa to address their sensitivity and, as with other
taxa, take the form of a dose response curve, allowing for variation in
individual responses given different contexts.
Regarding the comment that NMFS claims that suitable alternative
habitat options exist if beaked whales are disturbed during feeding is
not credible, we first direct the Commenter to the discussion of the
impacts of noise
[[Page 46323]]
exposure during feeding behaviors described in the Odontocete
subsection of the Analysis and Negligible Impact Determination section,
which discusses the energetic impacts that interruption of feeding
bouts can have on feeding odontocetes if interruptions occur over
repeated sequential days. However, in the context of the MITT Study
Area, as predicted and discussed, the magnitude and severity of takes
is such that disturbance of low-moderate levels is expected to occur on
no more than a few non-sequential days for any individual beaked
whales, which would not result in the sort of energetic concerns that
the Commenter is raising. Further, the Commenter repeatedly references
concerns for small resident populations of beaked whales with high site
fidelity, but there are no data to confirm the population structure of
beaked whales in this area and, again, the magnitude and severity is
low such that, regardless, adverse energetic impacts would be unlikely
to result from Navy activities.
Regarding the recommendation that acoustic monitoring be
implemented in order to provide better density information for beaked
whales, and to better understand behavioral responses, as noted in the
Changes from the Proposed Rule section, the Navy will be co-funding the
Pacific Marine Assessment Program for Protected Species (PACMAPPS)
survey in spring-summer 2021 to help document beaked whale occurrence,
abundance, and distribution in the Mariana Islands. This effort will
include deployments of a towed acoustic array as well as floating
passive acoustic buoys. The Navy has further committed to monitoring
future beaked whale occurrence within select portions of the MITT Study
Area starting in 2022 (so as to not duplicate PACMAPPS efforts).
Regarding the recommendation that the Navy be more transparent in
their monitoring and sharing data indicating the timing of Navy
activities in relation to strandings, there is certain information that
the Navy is unable to share freely because it is classified. Specific
classified information is shared in the Navy's classified monitoring
reports, and the Navy has always cooperated to provide additional
detail in an unclassified format when needed. Further, though, the Navy
has specifically targeted, for monitoring pursuant to this rule,
increased analysis for any future beaked whale stranding in the Mariana
Islands to include detailed Navy review of available records of sonar
use.
Regarding the comment that additional personnel and support for
local stranding response and records is needed in order to better
investigate causes of strandings that coincide with Navy activities in
the MITT Study Area, as discussed in the rule the Navy has committed to
continuing to fund additional stranding response/necropsy analyses for
the Pacific Islands region. Further, the Navy is submitting a proposal
through the annual Federally Funded Research and Development Center
(FFRDC) call to fund the Center for Naval Analysis (CNA) to develop a
framework to improve the analysis of single and mass stranding events,
including the development of more advanced statistical methods to
better characterize the uncertainty associated with data parameters.
Last, the Commenter notes that in order to detect any trend in the
population, there is a strong need to conduct consistent surveys, with
adequate methods for the species under consideration, over multiple
years. NMFS and the Navy do not disagree with this recommendation and,
as noted, the Navy and NMFS are co-funding the PACMAPPS survey and the
Navy has committed to additional beaked whale surveys. However, the
ability to conduct consistent surveys is dependent upon the
availability of resources at both NMFS and the Navy, and surveys may
not always be conducted with the ideal regularity.
Comment 21: A Commenter recommends that the Navy conduct more
visual monitoring efforts, at sea and along coastlines, for stranded
cetaceans before, during, and after naval exercises.
Response: It is not practicable for the Navy to conduct additional
visual monitoring at sea and along the coastlines for stranded
cetaceans before, during, and after training and testing activities
beyond what will occur through the procedural mitigation requirements
under this rule. Pursuant to the mitigation, the Navy will be required
to conduct monitoring for marine mammals before, during, and after in-
water explosive exercises as described in the Mitigation Measures
section of this rule. During operations of hull-mounted mid-frequency
sonar and low frequency sonar above 200 dB, monitoring will be
conducted in support of mitigation requirements, and during all
operations of any sort the Navy will be required to report if any
injured or dead marine mammals are observed and follow established
incident reporting procedures. In addition, the Navy has been providing
funding to augment stranding response and necropsy examinations in
Hawaii and the Mariana Islands since 2018. Additional funding to
continue this support has been programmed and is pending issuance in
FY20.
Comment 22: A Commenter recommends that NMFS consider the full
range of options in determining the mitigation measures needed to meet
its responsibility under both the ``negligible impact'' and ``least
practicable adverse impact'' provisions of the MMPA for beaked whales.
Given the expertise needed to produce an optimal mitigation plan, the
Commenter strongly advises NMFS to assemble a group of subject-matter
experts, including experts on beaked whale distribution, monitoring,
and conservation from the Southwest Fisheries Science Center,
researchers from the Pacific Islands Fisheries Science Center who have
led the work on beaked whales in the archipelago, and outside experts
on the conservation biology of beaked whales.
Response: The procedural mitigation measures required by the final
rule provide protection for all species of marine mammals by reducing
the probability and severity of impacts from active sonar and
explosives. As noted, there is limited data available addressing the
distribution of marine mammals in the Marianas, and there is no
information supporting the existence of any known biologically
important areas that would warrant the development of a geographic
mitigation area for beaked whales. NMFS had thorough discussions with
the Navy about the possibility of crafting a mitigation measure to
minimize any potential risk that Navy activities could contribute in
any way to the potential stranding of beaked whales. These discussions
included consideration of all public comments that recommended beaked
whale mitigation measures. However, despite years of field surveys
conducted under interagency agreements between the Navy and NMFS' PIFSC
along with Navy funded beaked whale monitoring, there remains a lack of
scientific information available on beaked whale distribution and other
essential species information in the Mariana Islands. Without
sufficient scientific data on beaked whale habitat use, bathymetry, and
seasonality, and from that a better understanding of the circumstances
that could affect the likelihood of a stranding in the MITT Study Area,
NMFS is unable to develop mitigation measures that would meaningfully
reduce the likelihood of stranding and/or will not result in
unreasonable operational/practicability concerns.
Consequently, NMFS recommended to the Navy that the two agencies
convene a panel of experts, both from
[[Page 46324]]
the region, as well as beaked whale behavioral response experts from
other geographic areas, and Navy experts on biology, operations, and
mitigation to review the status of the science, identify data gaps, and
identify information applicable for consideration for future mitigation
through the Adaptive Management process. The Navy has agreed to fund
and co-organize this effort. Additional measures that the Navy has
agreed to conduct to increase understanding and decrease uncertainty
around beaked whales in the MITT Study Area are discussed in the
Monitoring section.
Comment 23: A Commenter recommends that the impact assessment
consider whether beaked whales would be startled by explosions or
active sonar causing them to rush from great depths to the surface at
dangerous speed causing injury from gas expansion in their blood and
whether repeated impacts causing TTS could lead to PTS.
Response: The proposed rule addressed the impacts the commenter
raises in the Potential Effects of Specified activities on Marine
Mammals and Their Habitat section (Acoustically Mediated Bubble Growth
and other Pressure-related Injury). Further, NMFS has expanded the
discussion and rationale describing why the Navy's activities are not
expected to result in the mortality of beaked whales in the Stranding
section of this final rule.
As described in the proposed rule, very prolonged or repeated
exposure to sound strong enough to elicit TTS, or shorter-term exposure
to sound levels well above the TTS threshold, can cause PTS, however,
circumstances that would be expected to lead to this are not present
for Navy activities in the MITT Study Area. For this rulemaking, the
Navy's modeling has considered the proximity of marine mammals to Navy
activities and the likelihood of exposure to levels above which TTS or
PTS might be incurred, throughout a full day (i.e., considering
potential repeated exposures within a day), and very few PTS takes are
expected (see the Estimated Take of Marine Mammals section). Further,
as discussed in the Analysis and Negligible Impact Determination
section, there is no information suggesting that any marine mammals
will be exposed to levels resulting in TTS across more than a few non-
sequential days, much less at a level or duration that is expected to
accrue to PTS across those days.
Also of note, ongoing research on beaked whale response to sonar
does not indicate a panic response and rush to the surface. Instead,
beaked whales move away from the source underwater and increase the
slope of their ascent glide to bring them further from the source
(Falcone et al. 2017).
Comment 24: A Commenter stated that similar to beaked whales, NMFS
has failed to analyze seriously whether melon[hyphen]headed whales and
other marine mammal species known to be vulnerable to harm from Navy
sonar and explosives are likely to suffer injury and/or death from MITT
activities.
Response: There have not been significant instances of stranding of
melon-headed whales or other blackfish species in the Mariana Islands.
Effects analyses concluding that strandings of these species are
unlikely to result from the Navy's activities are contained in the 2020
MITT FSEIS/OEIS. In review of NMFS' and Guam Department of
Agriculture's Division of Aquatic and Wildlife Resources stranding data
from 1962 through February 2019, only two instances of melon-headed
whale strandings were reported (1980 and 2015). Stranding data for
other species over the same time period include: false killer whale 3
(2000, 2003, 2007), dwarf sperm whale 4 (1970, 1974, 1993, 2002), pygmy
killer whale 1 (1974), pygmy sperm whale 3 (1989 (2), 1997), sperm
whale 6 (1962, 1993 (2), 2011, 2012, 2013), and short-finned pilot
whale 1 (1980). Given the low numbers of strandings of these species in
the Marianas and the absence of any evidence of association with active
sonar operation, the likelihood that Navy activities would result in
serious injury or mortality of these species is considered
discountable.
Comment 25: A Commenter stated that NMFS assumes, counter to the
available evidence, that beaked whales around the Mariana Archipelago
have no population structure and are part of large, cosmopolitan
populations. While limited information on population structure is
available, the best available science shows differences in the
echolocation signal frequency of Blainville's beaked whales between the
Northern Marianas Islands and other locations in the Pacific, Western
Atlantic, and Gulf of Mexico, indicative of a population specific to
the Northern Marianas Islands. This finding is consistent with studies
in other parts of the world, which have demonstrated remarkable site-
fidelity in beaked whale populations. Range-limited populations have
been found on the shelf break approximately 50 km east of Cape
Hatteras, as well as off Canada, in the Mediterranean, off Southern
California, in the Bahamas, and around the Hawaiian Islands.
Response: There is no satellite tag or photographic identification
data supporting the assertion that the populations around the Marianas
are resident populations, much less identifying what the size or shape
of those resident populations might be within the Mariana Islands
(i.e., abundance and range size). The Commenter points to data
differentiating vocalizations of Blainville's beaked whales in the
Mariana Islands versus other parts of the Pacific, and to the presence
of known resident populations of beaked whales in Hawaii and other
islands of the world. These points support the potential for resident
populations to exist in the Marianas, but do not provide any
information that would support analyzing impacts in a manner
differently than was done by the Navy and NMFS. Specifically, for
example, even if the beaked whales within the Marianas comprise a
separate population from those elsewhere in the Pacific, it would not
suggest that beaked whales should be analyzed differently than they
were within the MITT Study Area.
While NMFS cannot explicitly define the beaked whale population
structure at this time, the magnitude and severity of the estimated
take and the negligible impact analyses remain valid and applicable
based on the best available science regardless of whether the beaked
whales in the MITT Study Area are from a larger global population or a
Marianas Islands associated population. NMFS and the Navy are committed
to actions that will expand our understanding of beaked whales,
including their distribution in the MITT Study Area (see the Monitoring
and Adaptive Management sections below for detailed descriptions). For
example, the Navy will co-fund the Pacific Marine Assessment Program
for Protected Species (PACMAPPS) survey in spring-summer 2021 to help
document beaked whale occurrence, abundance, and distribution in the
Mariana Islands. This effort will include deployments of a towed array
as well as floating passive acoustic buoys. The Navy will monitor
future beaked whale occurrence within select portions of the MITT Study
Area starting in 2022. Additionally, the Navy will include Cuvier's
beaked whales as a priority species for analysis under a 2020-2023 Navy
research-funded program entitled Marine Species Monitoring for
Potential Consequences of Disturbance (MSM4PCOD). Finally, the Navy
will fund and co-organize with NMFS an expert panel to provide
recommendations on scientific data gaps and uncertainties.
[[Page 46325]]
Mitigation and Monitoring
Least Practicable Adverse Impact Determination
Comment 26: A Commenter cited two judicial decisions and commented
that the ``least practicable adverse impact'' standard has not been
met. The Commenter stated that contrary to the Pritzker Court decision,
NMFS, while clarifying that population-level impacts are mitigated
``through the application of mitigation measures that limit impacts to
individual animals,'' has again set population-level impact as the
basis for mitigation in the proposed rule. Because NMFS' mitigation
analysis is opaque, it is not clear what practical effect this position
may have on its rulemaking. The Commenter stated that the proposed rule
is also unclear in its application of the ``habitat'' emphasis in the
MMPA's mitigation standard, and that while NMFS' analysis is opaque,
its failure to incorporate or even, apparently, to consider viable
time-area measures suggests that the agency has not addressed this
aspect of the Pritzker decision. The Commenter argued that the MMPA
sets forth a ``stringent standard'' for mitigation that requires the
agency to minimize impacts to the lowest practicable level, and that
the agency must conduct its own analysis and clearly articulate it and
not just parrot what the Navy says. The baselessness of this approach
can be seen from the outcome of the Conservation Council decision,
where the parties were able to reach a settlement agreement
establishing time-area management measures, among other things, on the
Navy's Southern California and Hawaii Range Complexes notwithstanding
NMFS' finding, following the Navy, that all such management measures
would substantially affect military readiness and were not practicable.
Unfortunately, there is no indication in the proposed rule that NMFS
has, as yet, done anything different here.
Response: First, the Commenter's reference to mitigation measures
implemented pursuant to a prior settlement agreement is entirely
inapplicable to a discussion of NMFS' responsibility to ensure the
least practicable adverse impact under the MMPA. Specifically, for
those areas that were previously covered under the 2015 settlement
agreement for the HSTT Study Area, it is essential to understand that:
(1) The measures were developed pursuant to negotiations with the
plaintiffs and were specifically not selected and never evaluated based
on an examination of the best available science that NMFS otherwise
applies to a mitigation assessment and (2) the Navy's agreement to
restrictions on its activities as part of a relatively short-term
settlement (which did not extend beyond the expiration of the 2013
regulations) did not mean that those restrictions were practicable to
implement over the longer term.
Regarding the remainder of the comment, NMFS disagrees with much of
what the Commenter asserts. First, we have carefully explained our
interpretation of the least practicable adverse impact standard and how
it applies to both stocks and individuals, including in the context of
the Pritzker decision, in the Mitigation Measures section. Further, we
have applied the standard correctly in this rule in requiring measures
that reduce impacts to individual marine mammals in a manner that
reduces the probability and/or severity of population-level impacts.
When a suggested or recommended mitigation measure that would
reduce impacts is not practicable, NMFS has explored variations of that
mitigation to determine if a practicable form of related mitigation
exists. This is clearly illustrated in NMFS' independent mitigation
analysis process explained in the Mitigation Measures section of the
final rule. First, some types of mitigation required under this rule
are area-specific and vary by mitigation area, demonstrating that NMFS
has engaged in a site-specific analysis to ensure mitigation is
tailored when practicability demands, i.e., some forms of mitigation
were practicable in some areas but not others. For instance, while it
was not practicable for the Navy to restrict all use of the Chalan
Kanoa Reef and Marpi Reef Geographic Mitigation Areas, NMFS did expand
the seaward extent of the areas out to the 400-m isobath. Additionally,
while it was not practicable for the Navy to eliminate all training in
those two Geographic Mitigation Areas, restrictions in those areas have
been expanded such that the Navy will not use explosives year-round and
MF1 MFAS will be limited to 20 hours between December 1 and April 30
annually to minimize impacts from sonar on humpback whales during the
time when they are engaged in important reproductive behaviors.
Regarding the comment about mitigation of habitat impacts, marine
mammal habitat value is informed by marine mammal presence and use and,
in some cases, there may be overlap in measures for the species or
stock directly and for use of habitat. In this rule, we have required
time-area mitigations based on a combination of factors that include
higher densities and observations of specific important behaviors of
marine mammals themselves, but also that clearly reflect preferred
habitat (e.g., reproductive areas of Marpi and Chalan Kanoa Reefs,
resting habitat for spinner dolphins in Agat Bay). In addition to being
delineated based on physical features that drive habitat function
(e.g., bathymetric features), the high densities and concentration of
certain important behaviors (e.g., breeding, resting) in these
particular areas clearly indicate the presence of preferred habitat.
The Commenter seems to suggest that NMFS must always consider separate
measures aimed at marine mammal habitat; however, the MMPA does not
specify that effects to habitat must be mitigated in separate measures,
and NMFS has clearly identified measures that provide significant
reduction of impacts to both ``marine mammal species and stocks and
their habitat,'' as required by the statute.
NMFS agrees, however, that the agency must conduct its own
analysis, which it has done here, and not just accept what is provided
by the Navy. That does not mean, however, that NMFS cannot review the
Navy's analysis of effectiveness and practicability of its proposed
mitigation measures, which by regulation the Navy was required to
submit with its application, and concur with those aspects of the
Navy's analysis with which NMFS agrees. The Commenter seems to suggest
that NMFS must describe in the rule in detail the rationale for not
adopting every conceivable permutation of mitigation, which is neither
reasonable nor required by the MMPA. NMFS has described our well-
reasoned process for identifying the measures needed to meet the least
practicable adverse impact standard in the Mitigation Measures section
in this rule, and we have followed the approach described there when
analyzing potential mitigation for the Navy's activities in the MITT
Study Area. Responses to specific recommendations for mitigation
measures provided by the Commenter on the proposed rule are discussed
separately.
Comment 27: A Commenter noted that they have previously indicated
that, under the least practicable adverse impact requirement, and more
generally under the purposes and policies of the MMPA, Congress
embraced a policy that minimizes, whenever it is practicable, the risk
of killing or seriously injuring a marine mammal incidental to an
activity subject to section 101(a)(5)(A), including taking measures in
an authorization to eliminate or reduce the
[[Page 46326]]
likelihood of lethal taking. Accordingly, the Commenter had recommended
that NMFS address this point explicitly in its least practicable
adverse impact analysis and clarify whether it agrees that the
incidental serious injury or death of a marine mammal always should be
considered an adverse impact for purposes of applying the least
practicable adverse impact standard. In the preamble to the Atlantic
Fleet Training and Testing (AFTT) final rule, NMFS indicated that it
was unnecessary or unhelpful to address explicitly the point made by
the Commenter that an incidental death or serious injury of a marine
mammal should always be considered an adverse impact on the species or
stock (83 FR 57117). The Commenter disagrees. The Commenter does not
see how NMFS can meet the mandate of the MMPA to reduce adverse impacts
to the lowest level practicable if it does not first identify clearly
which impacts are adverse and may require mitigation under section
101(a)(5)(A)(i)(II)(aa). The Commenter appreciates NMFS' statement that
it has adopted a practice to mitigate mortality to the greatest degree
possible, but disagrees with the agency's conclusions that one
mortality does not affect the population in a quantifiable or
meaningful way. However, the MMPA requires NMFS to go beyond that and
reduce any adverse impacts to the greatest extent practicable, even
though population-level impacts are not significant.
Response: NMFS continues to disagree that it is necessary or
helpful to explicitly address the point the Commenter raises
specifically in the discussion on the least practicable adverse impact
standard. It is always NMFS' practice to mitigate serious injury and
mortality to the greatest degree possible, as death is the impact that
is most easily linked to reducing the probability of adverse impacts to
populations. However, we cannot agree that one mortality will always
decrease any population in a quantifiable or meaningful way. For
example, for very large populations, one mortality may fall well within
typical known annual variation and not have any effect on population
rates. Mortality is not anticipated or authorized in this rule.
Comment 28: A Commenter continues to recommend that NMFS clearly
separate its application of the least practicable adverse impact
requirement from its negligible impact determination. Once NMFS
determines that an applicant's proposed activities would have a
negligible impact, it still has a responsibility to determine whether
the activities would nevertheless have adverse impacts on marine mammal
species and stocks and their habitat. If so, NMFS must condition the
authorization to eliminate or reduce those impacts whenever, and to the
greatest extent, practicable. As the statute is written, it is
inappropriate to conflate the two standards, as NMFS seems to be doing.
Response: NMFS has made clear in this and other rules that the
agency separates its application of the least practicable adverse
impact requirement in the Mitigation Measures section from its
negligible impact analyses and determinations for each species or stock
in a separate section. Further, NMFS has made this separation clear in
practice for years by requiring mitigation measures to reduce impacts
to marine mammal species and stocks and their habitat for all projects,
even those for which the anticipated take would clearly not approach
the negligible impact threshold, even in the absence of mitigation.
Comment 29: A Commenter recommended that NMFS follow an analysis
consisting of three elements to (1) determine whether the impacts of
the proposed activities are negligible at the species/stock level, (2)
if so, determine whether some of those impacts nevertheless are adverse
either to marine mammal species or stocks or key marine mammal habitat,
and (3) if so, whether it is practicable for the applicant to reduce or
eliminate those impacts through modifying those activities or by other
means (e.g., requiring additional mitigation measures to be
implemented).
Response: In the Mitigation Measures section of the rule, NMFS has
explained in detail our interpretation of the least practicable adverse
impact standard, the rationale for our interpretation, and then how we
implement the standard. The method the agency is using addresses all of
the necessary components of the standard and produces effective
mitigation measures that result in the least practicable adverse impact
on both the species or stocks and their habitat. The Commenter has
failed to illustrate why NMFS' approach is inadequate or why the
Commenter's proposed approach would be better, and we therefore decline
to accept the recommendation.
Comment 30: Regarding the habitat component of the least
practicable adverse impact standard, a Commenter recommends that NMFS
(1) adopt a clear decision-making framework that recognizes the species
and stock component and the marine mammal habitat component of the
least practicable adverse impact provision and (2) always consider
whether there are potentially adverse impacts on marine mammal habitat
and whether it is practicable to minimize them. The MMPA requires that
NMFS address both types of impacts, not that there be no overlap
between the mitigation measures designed to reduce those impacts.
Response: NMFS' decision-making framework for applying the least
practicable adverse impact standard clearly recognizes the habitat
component of the provision (see Mitigation Measures section of the
rule). NMFS does always consider whether there are adverse impacts on
habitat and how they can be mitigated. Marine mammal habitat value is
informed by marine mammal presence and use and, in some cases, there
may be overlap in measures for the species or stock directly and for
use of habitat. In this rule, we have required time-area mitigation
measures based on a combination of factors that include higher
densities and observations of specific important behaviors of marine
mammal species themselves, but also that clearly reflect preferred
habitat (e.g., reproductive habitat off Marpi and Chalan Kanoa Reefs
and resting habitat in Agat Bay). In addition to being delineated based
on physical features that drive habitat function (e.g., bathymetric
features), the high densities and concentration of certain important
behaviors (e.g., reproduction, feeding, resting) in these particular
areas clearly indicate the presence of preferred habitat. The Commenter
seems to suggest that NMFS must include mitigation measures aimed at
marine mammal habitat that are wholly separate from addressing adverse
impacts directly on the species or stocks. However, the MMPA does not
specify that effects to habitat must be mitigated in separate measures,
and NMFS has clearly included measures that provide significant
reduction of impacts to both marine mammal species or stocks and their
habitat, as required by the statute.
Comment 31: A Commenter recommended that NMFS rework its evaluation
criteria for applying the least practicable adverse impact standard to
separate the factors used to determine whether a potential impact on
marine mammals or their habitat is adverse and whether possible
mitigation measures would be effective.
Response: In the Mitigation Measures section, NMFS has explained in
detail our interpretation and application of the least practicable
adverse impact standard. The Commenter has recommended an alternate way
of
[[Page 46327]]
interpreting and implementing the least practicable adverse impact
standard, in which NMFS would consider the effectiveness of a measure
in our evaluation of its practicability. The Commenter erroneously
asserts that NMFS currently considers the effectiveness of a measure in
a determination of whether the potential effects of an activity are
adverse, but the Commenter has misunderstood NMFS' practice--rather,
NMFS appropriately considers the effectiveness of a measure in the
evaluation of the degree to which a measure will reduce adverse impacts
on marine mammal species or stocks and their habitat, as a less
effective measure will less successfully reduce these impacts on marine
mammals. Further, the Commenter has not provided information that shows
that their proposed approach would more successfully evaluate
mitigation against the LAPI standard, and we decline to accept it.
Comment 32: A Commenter stated that although NMFS has written
extensively on the least practicable adverse impact standard, it
remains unclear exactly how each authorization's proposed ``mitigation
measures are sufficient to meet the statutory legal standard,'' or even
what standard NMFS is using. As such, the Commenter again recommends
that NMFS address these shortcomings by adopting a simple, two-step
analysis that more closely tracks the statutory provisions being
implemented. As the Commenter has stated previously, the first step
should be to identify impacts on marine mammal species or stocks or
their habitat that, although negligible, are nevertheless adverse. If
such impacts are identified, then NMFS must identify and require the
applicant to adopt measures to reduce those impacts to the lowest level
practicable. If NMFS is using some other legal standard to implement
the least practicable adverse impact requirements, the Commenter
further recommends that NMFS provide a clear and concise description of
that standard and explain why it believes it to be ``sufficient'' to
meet the statutory legal requirements.
Response: NMFS disagrees with the Commenter's assertion that
analysis of the rule's mitigation measures under the least practicable
adverse impact standard remains unclear or that the suggested
shortcomings exist. Further, the Commenter provides no rationale as to
why the two-step process they describe is better than the process that
NMFS uses to evaluate the least practicable adverse impact and,
therefore, we decline to accept the recommendation.
Comment 33: A Commenter stated that since NMFS has expounded on the
least practicable adverse impact standard at some length in a series of
proposed authorizations, it has been an evolutionary process that
varies depending on each specific situation. The Commenter continues to
recommend that NMFS adopt general regulations to govern the process and
set forth the basic steps and criteria that apply across least
practicable adverse impact determinations. Those standards should not
be shifting on a case by-case basis, as now appears to be the case.
Rather, the analytical framework and decision-making standards should
be consistent across authorizations. Variations between authorizations
should be based on the facts underlying each application, not the
criteria that underpin the least practicable adverse impact standard.
Response: The commenter misunderstands the agency's process.
Neither the least practicable adverse impact standard nor NMFS' process
for evaluating it shifts on a case-by-case basis. Rather, as the
Commenter suggests should be the case, the evaluation itself is case-
specific to the proposed activity, the predicted impacts, and the
mitigation under consideration.
Regarding the recommendation to adopt general regulations, we
appreciate the recommendation and may consider the recommended approach
in the future. However, providing directly relevant explanations of
programmatic approaches or interpretations related to the incidental
take provisions of the MMPA in a proposed incidental take authorization
is an effective and efficient way to provide information to and solicit
focused input from the public. Further, this approach affords the same
opportunities for public comment as a stand-alone rulemaking would.
Geographic Mitigation Measures
Comment 34: A Commenter cites the judicial decision in Pritzker,
and suggests that NMFS should adjust its approach to geographic
mitigation as follows: First, NMFS must not dismiss the existence of
persistent areas of primary productivity. Second, NMFS must not
conflate the lack of survey effort with an absence of biologically
important habitat. Third, NMFS, in following the Navy, overlooks
evidence of island-associated small or resident populations, and
relative risk to those populations. It is entirely remiss for NMFS to
ignore evidence of small and resident populations within the MITT Study
Area and afford them no additional protections.
Response: To support its argument that NMFS must not dismiss the
existence of persistent areas of primary productivity, the Commenter
cites to the 2019 MITT DSEIS/OEIS and its general discussion of the
West Marianas Ridge area and areas of productivity, and references some
general information about how certain features may be tied to
biodiversity hotspots. The West Marianas Trench is a huge area hundreds
of miles long. The commenter does not provide any information about
particular features or areas that are specifically known to be
important to marine mammals in the West Marianas Trench, much less
provide any specific recommendations about how geographic mitigation
might potentially provide a reduction in impacts that the Navy's
activities might be having on marine mammal species or stocks and their
habitat. As described in section I.4.1 of the 2020 MITT FSEIS/OEIS,
which NMFS reviewed and concurs with, the available data do not
indicate that the West Mariana Ridge or surrounding area is an area of
key biological importance for marine mammals or other marine species,
nor is it clear that limiting the use of sonar and explosives in the
area would result in an avoidance or reduction of impacts. Therefore,
the West Mariana Ridge area does not warrant geographic mitigation.
NMFS does not dismiss the existence of persistent areas of primary
productivity, however, NMFS is unaware of, and the Commenter has failed
to demonstrate the existence of, data supporting areas or habitat of
specific importance to marine mammals, nor has the Commenter
recommended any particular geographic mitigation measure. Additional
discussion of areas of primary productivity is included below in the
response to Comment 35.
Second, the commenter asserts that NMFS must not conflate the lack
of survey effort with an absence of biologically important habitat.
NMFS has not done this. In the final rule, we have clarified that there
are no known biologically important areas for most of the species in
the MITT Study Area. In addition, while both the Navy and NMFS have
discussed the paucity of survey data and habitat information in and
around the Marianas, and the limited amount of information indicating
specific important habitat for marine mammals, we have not suggested
that this lack of data indicates that no biologically important areas
exist. However, in the absence of data supporting a specific area in
which biologically important behaviors are known to be concentrated, or
important
[[Page 46328]]
habitat is otherwise located, and in which a reasonable argument can be
made that limitation of Navy activities would meaningfully reduce
impacts to marine mammal species or stocks and their habitat, it is not
reasonable to require geographic mitigation beyond the procedural
mitigation that is already in place to reduce impacts to all marine
mammals in all locations.
Third, the Commenter asserts that NMFS overlooks evidence of
island-associated small or resident populations, and relative risk to
those populations. NMFS and the Navy acknowledge the potential for
island-associated odontocete populations in the Marianas and, in fact,
the species that the Commenter focuses on in their comment (spinner
dolphins) is the driver for the Agat Bay Mitigation Area, which will
minimize impacts to spinner dolphins resting in a Bay on the west side
of Guam where they are known to concentrate. However, as discussed in
more detail in section I.4.2 of the 2020 MITT FSEIS/OEIS, which NMFS
reviewed and concurs with, while some of the species that have been
identified as island-associated residents in Hawaii have been detected
from nearshore small boat surveys in the Marianas, these same species
have been detected using offshore areas beyond the 3,500-m isobath in
offshore surveys or by satellite tags. There is no satellite tag or
photographic identification data supporting the assertion that the
populations around the Marianas are resident populations, much less
that their ranges are spatially limited in a manner that would support
the consideration of geographic mitigation measures.
Comment 35: A Commenter recommended that NMFS should consider the
guidelines for capturing biologically important marine mammal habitat
in data-poor areas, provided by NMFS' subject-matter experts and
addressed by the Ninth Circuit Court of Appeals in NRDC v. Pritzker 828
F.3d 1125 (9th Cir. 2016), as those guidelines are relevant to the
broader MITT Study Area, much of which is comprised of data-poor,
offshore areas. These ``White Paper'' guidelines call for: (1)
Designation as Offshore Biologically Important Areas (OBIAs) of all
continental shelf waters and waters 100 km seaward of the continental
slope as biologically important for marine mammals; (2) establishment
of OBIAs within 100 km of all islands and seamounts that rise within
500 m of the surface; and (3) nomination as OBIAs of high-productivity
regions that are not included in the continental shelf, continental
slope, seamount, and island ecosystems above as biologically important.
Response: In discussing OBIAs, the commenter references a process
and set of recommendations that were specifically developed in the
context of the Navy's SURTASS LFA sonar activities, in which five
vessels operated primarily in the Pacific Ocean use low frequency
active sonar only in deep offshore waters to train and search for enemy
submarines. The geographic area of the SURTASS LFA regulations includes
the western and central North Pacific Ocean and eastern Indian Ocean
outside of the territorial seas of foreign nations (generally 12 nmi
(22 km) from most foreign nations). By referencing designation as
OBIAs, we assume the Commenter is suggesting restricting active sonar
(at a minimum) in the areas identified. Below we discuss the
consideration of these areas for mitigation in the MITT Study Area.
Regarding recommendations (1) and (2), restricting the Navy's MITT
activities in these areas is impracticable, as many of the Navy's
activities specifically necessitate use of the varied bathymetry that
occurs between the continental slope and 100 km seaward or around
seamounts, and many can occur only within designated training or
testing areas that fall within this area.
The Navy has communicated to NMFS that the MITT Study Area includes
dedicated range assets, special use airspace, and other infrastructure
to support training and testing activities that would not be available
to the Navy should it have to conduct activities beyond the continental
shelf waters (including a 100 km buffer). Mid-frequency and high-
frequency sonar sources, which are the primary sources used in the MITT
training and testing activities, have a much smaller propagation range
than LF sources. Therefore, moving further and further offshore, from
seamounts, from islands, etc. would result in completely ineffective
training/testing because the sonar system would not be able to perform
in locations of the bathymetries required to meet proficiency with
standoff/buffer distances proposed. Shelf, slope, sea mount, and
shallow island associated waters are the type of complex training
environments required by the Navy since those are the types of
bathymetric conditions that deployed units to the Navy's 7th Fleet will
be most presented with when operating in the Philippine Sea, South
China Sea, etc. Therefore, it is impracticable to limit activities in
the locations recommended by the white paper.
Also, regarding the 100 km offshore of the slope limitation,
density data from other regions where more granular survey data is
available generally indicate that while some species may typically be
more concentrated in shelf and slope waters, certain mysticete species
and sperm whales often have higher densities outside of the mitigation
area the Commenter suggests (100 km beyond the Continental Slope), and
focusing activities in those areas would shift impacts from more
coastal species to more pelagic species, making any overall reduction
in impacts uncertain. Regarding seamounts, while data have shown higher
species diversity or aggregations of some species at some seamounts
during certain periods of time (Morato et al., 2008), they also suggest
that these aggregations are often specific to a seamount or time period
(i.e., not all seamounts exhibit these aggregations at all times) and,
further, that marine mammal species are more loosely associated with
seamounts than other taxa (Pitcher et al., 2007). When this information
is considered in combination with the fact that no more than a few
takes of any individual marine mammal are expected throughout the MITT
Study Area annually, any potential reduction in impacts would be
limited. For additional information regarding marine mammal use of
seamounts, see the White Paper Specific Recommendations section of
NMFS' Final Rule for SURTASS LFA Sonar (84 FR 40132, 40192, August 13,
2019). Given the lack of evidence supporting the likelihood that this
approach would provide meaningful reduction of impacts to marine mammal
species and their habitat in the MITT Study Area, combined with the
impracticability for Navy implementation, NMFS finds that these
measures are not warranted beyond the procedural mitigation measures
that reduce the likelihood of injury or more severe behavioral impacts
for all species in all areas.
Regarding restricting Navy activities in areas of high
productivity, we first refer the reader to our response immediately
above, which addresses the West Marianas Trench, and further note that
the Commenter does not identify, and nor is NMFS aware of, any other
known areas of high productivity within the MITT Study Area. More
generally, areas of the highest productivity tend to be found in areas
of high latitude (not found in the MITT Study Area) or near river
mouths (small boat surveys in the MITT Study Area have already allowed
for the identification of specifically important nearshore areas for
marine mammals, which have been designated as geographic mitigation
areas)
[[Page 46329]]
(Wolverton, 2009). More moderate areas of productivity tend to occupy
large, and often ephemeral, offshore areas that are difficult to
consistently define because of interannual spatial and temporal
variability. Regions of high productivity have the potential to provide
good foraging habitat for some species of marine mammals, however,
there is not sufficient data to support the designation of any specific
area. Further, the fact that no more than a few takes of any individual
marine mammal are expected throughout the MITT Study Area annually
suggests that any potential reduction in impacts would be limited. When
this limited benefit is balanced against the general impracticability
of restricting Navy training and testing in large portions of the MITT
Study Area, and given the lack of information to identify an
appropriate area, NMFS finds that this measure is not warranted beyond
the procedural mitigation measures that reduce the likelihood of injury
or more severe behavioral impacts for all species in all areas.
Comment 36: A Commenter recommends that NMFS determine whether the
Navy's implementation of geographic mitigation measures at the North
Guam, Ritidian Point, and Tumon Bay Offshore Areas would be practicable
and if so, include them as mitigation areas in the final rule. In
either case, all of the relevant information for North Guam, Ritidian
Point, and Tumon Bay Offshore Areas must be included in the preamble to
the final rule.
Response: NMFS has considered the best available information (which
for mitigation measures discussed here and below includes both best
available science and information on practicability) for these
suggested mitigation areas. The areas of North Guam, Ritidian Point,
and Tumon Bay Offshore Areas were reviewed as potential mitigation
areas. While sightings and transits of the area by some species were
noted in review of available scientific research, there is currently no
information on specific uses for biologically important life processes
beyond normal species broad-area occurrence (e.g., the areas are not
exclusive feeding areas, migration routes, or breeding locations).
Given this, there is no evidence that limiting operations in these
areas would reduce impacts on marine mammals, and accordingly, no
geographic mitigation is warranted, regardless of whether it would be
practicable.
Comment 37: A Commenter recommends that NMFS should establish
mitigation areas for spinner dolphin resting habitat at Bile Bay, Tumon
Bay, and Double Reef, Guam, and Tanapaq Bay, Saipan.
Response: NMFS has considered the best available information for
these suggested mitigation areas. Previously reported spinner dolphin
high-use areas nearshore at Guam include Bile Bay, Tumon Bay, Double
Reef, as well as north Agat Bay, and off Merizo (Cocos Lagoon area),
where these animals congregate during the day to rest (Amesbury et al.,
2001; Eldredge, 1991). More recently, high-use areas have included Agat
Bay; the Merizo channel, tucked into the several small remote bays
between Merizo and Facpi Point; Piti Bay; Hagatna; Tumon Bay; and Pugua
Point (Ligon et al., 2011). During the 2010-2018 small boat surveys in
the Mariana Islands, there were 157 encounters with pods of spinner
dolphins (Hill et al., 2019). The approximate distance from shore for
these encounters was 1 km, indicative of their preference for nearshore
habitat and prevalence in the MITT Study Area (Hill et al., 2017a; Hill
et al., 2018b; Hill et al., 2019). As described in Section I.3.3 (Agat
Bay Nearshore Geographic Mitigation Area) of the 2020 MITT FSEIS/OEIS,
the nearshore area of Agat Bay represents an area of biological
importance and is practicable for implementation, and has been included
in the final rule as a geographic mitigation area for spinner dolphin
resting behavior. The data suggesting numerous other locations around
Guam and other islands where resting behavior has been observed or has
the potential to occur (i.e., the habitat is suitable) indicates that
no single area is of particular concentration or biological importance.
See Section 3.4.1.32.2 (Geographic Range and Distribution) of the 2020
MITT FSEIS/OEIS for more information. Accordingly, specific geographic
mitigation for these areas, beyond the procedural mitigation measures
that reduce the likelihood of injury or more severe behavioral impacts
for spinner dolphins and all other species during all activities, is
not warranted.
Comment 38: A Commenter recommends extending the southern boundary
of the Agat Bay Nearshore Geographic Mitigation Area seaward to the 100
m depth contour and including a buffer area sufficient to accomplish
the goal of avoiding mass disruption of spinner dolphins, and expanding
the same restriction, at minimum, to dipping sonar.
Response: NMFS has considered the best available information for
this suggested mitigation area. The current western boundary of the
Agat Bay Nearshore Geographic Mitigation Area essentially follows the
100-m isobath except at the southern extent of the area. At its
northern extent, the area includes deeper waters beyond the 100-m
isobath to include an area with a cluster of sea turtle sightings. The
greater number of spinner dolphin sightings may indicate that the
northern or middle portion of the Agat Bay Nearshore Mitigation Area
may be of greater importance than the southern portion due to some
physical or biological features. The point of land at the southern end
of the Agat Bay Nearshore Mitigation Area is a convenient physical
feature for defining the area, and as with other sightings data, it is
reasonable to assume that animals just outside of the boundary of the
area may be transiting to (or from) the northern portion of the area
and that areas beyond the boundary do not constitute areas of any
particular biological significance. The expansion of the area to
include a buffer at the southern end would not be likely to
meaningfully further reduce impacts to spinner dolphins and is,
therefore, not warranted. Dipping sonar, as described in the Detailed
Description of the Specified Activities section, is used during ASW
exercises, which occur primarily more than 3 nmi from shore, and would
especially not occur in areas as shallow as Agat Bay and with a high
number of small tour boats. As also indicated previously, the vast
majority of the takes from sonar exposure are related to MF1 sonar, and
dipping sonar has a significantly lower source level and has not been
associated with any particular impacts of concern to dolphins. Given
this, there is no additional protective value to be gained by adding a
restriction on dipping sonar in this area and it is, therefore, not
warranted.
Comment 39: A Commenter recommends that NMFS should establish a
mitigation area for offshore Agat Bay encompassing the continental
shelf break and slope and extending out to the 2,000 m depth contour to
protect this potentially important calving and nursing area for
endangered sperm whales. Additionally the Commenter also recommends the
NMFS should establish a second mitigation area for sperm whale calving
and nursery habitat offshore of Apra Harbor, encompassing the
continental shelf break and slope and extending out to the 2,000 m
depth contour.
Response: NMFS has considered the best available information for
these suggested mitigation areas. While there were multiple sightings
of sperm whale calves (not in Agat Bay or concentrated in a particular
area) during the course of
[[Page 46330]]
the large boat surveys conducted around the Marianas in 2007, the
recommendation that NMFS should consider an area off Agat Bay as a
breeding and nursery area for sperm whales seems to be largely based on
two Associated Press File photographs, taken opportunistically by a
local photographer, showing a group of three adult sperm whales and a
calf during an encounter from a commercial dive boat on June 15, 2001,
``. . . about four miles off the coast of the Agat Marina in Guam''
(Bangs, 2001). During the 2010-2018 small boat surveys in the Mariana
Islands, a total of seven sperm whales were detected over four
encounters (in 2010, 2013, 2016, and 2018) in a median depth of
approximately 1,200 m and median distance from shore of approximately
12 km (Hill et al., 2017a; Hill et al., 2018c; Hill et al., 2018d; Hill
et al., 2019). Sightings and acoustic monitoring detections recorded
both before and since 2007 indicate that sperm whales range widely in
the MITT Study Area with no known areas of concentration in the Mariana
Islands. Sperm whales are highly nomadic, mobile predators, and the
available data do not support areas offshore of Agat Bay or Apra Harbor
as important reproductive areas for sperm whales in the MITT Study
Area. For instance, a sperm whale with a satellite tracking tag
attached traveled in deep offshore waters from west of Guam to west of
Saipan in less than 10 days (Hill et al. 2019). Accordingly, specific
geographic mitigation in these areas, beyond the procedural mitigation
measures that reduce the likelihood of injury or more severe behavioral
impacts for sperm whales and all other species during all activities,
is not warranted.
Comment 40: A Commenter recommended that NMFS should protect Cocos
Lagoon and the continental shelf and slope waters west of Cocos Island
seaward to the 2,000 m depth contour as an important habitat area for
multiple species, particularly breeding habitat for a possibly resident
pygmy killer whale population and resting habitat for spinner dolphin
at Cocos Island and Lagoon, Guam.
Response: NMFS has considered the best available information for
this suggested mitigation area. Like similar deep-water and deep-diving
species, pygmy killer whales are likely highly mobile in the marine
environment with no known concentration areas in the Mariana Islands.
There was only one pygmy killer whale sighting of a group of six
animals during the 2007 systematic survey of the MITT Study Area
(Fulling et al., 2011). The sighting occurred near the Mariana Trench,
south of Guam, where the bottom depth was over 4,413 m. This is
consistent with the known habitat preference of this species for deep,
oceanic waters. However, in the Mariana Islands, pygmy killer whale
sightings close to shore are not unexpected due to deep bathymetry
surrounding most islands. There is no information on population range
of pygmy killer whales off Guam (Hill et al., 2019), or any information
suggesting that the area recommended by the Commenter is of specific
biological importance such that mitigation measures would result in a
reduction of impacts. Therefore, consideration of geographic
mitigation, beyond the procedural mitigation measures that reduce the
likelihood of injury or more severe behavioral impacts for pygmy killer
whales and all other species during all activities, is not warranted.
See Section 3.4.1.26.1 (Geographic Range and Distribution) of the 2020
MITT FSEIS/OEIS for more information.
For spinner dolphin habitat, there are numerous other locations
around Guam and other islands where resting behavior has been observed
or has the potential to occur (i.e., the habitat is suitable), however,
the data suggest that no single area, including the area recommended by
the Commenter, is of particular biological importance (i.e., with the
predictable regular recurrence of larger pods of resting dolphins seen
at Agat Bay). See Section 3.4.1.32.2 (Geographic Range and
Distribution) of the 2020 MITT FSEIS/OEIS for more information. As
such, a mitigation area here is not likely to meaningfully reduce
impacts to spinner dolphins and, therefore, consideration of geographic
mitigation, beyond the procedural mitigation measures that reduce the
likelihood of injury or more severe behavioral impacts for spinner
dolphins and all other species during all activities, is not warranted.
Comment 41: A Commenter recommended that NMFS should designate a
mitigation area to protect, at minimum, the ten percent ``highest use
area'' for short-finned pilot whales in core use areas, west of Guam
and Rota.
Response: NMFS has considered the best available information for
this suggested mitigation area. During the 2010-2018 small boat surveys
in the Mariana Islands, short-finned pilot whale groups were
encountered on 23 occasions in a median depth of approximately 720 m
and median distance from shore of approximately 5 km, including one pod
of 35 individuals off Marpi Reef north of Saipan (Hill et al., 2014;
Hill et al., 2017a; Hill et al., 2018b; Hill et al., 2018d; Hill et
al., 2019). Satellite tags deployed on 17 individuals between 2013 and
2018 suggest multiple areas are used frequently by short-finned pilot
whales in the Marianas, including but not limited to areas west of Guam
and Rota (Hill et al., 2018d; Hill et al., 2019). Satellite tags on
short-finned pilot whales lasting from approximately 9-128 days showed
that individuals ranged from south at Tumon Bay off Guam to as far
north as the waters west of Anatahan (Hill et al., 2019). The Commenter
uses tag data from the movement of eleven individuals to suggest
probability density contours centered northwest of Guam, however,
multiple locations of eleven animals are not necessarily representative
of the distribution of all of the animals in the population.
Altogether, tag locations and visual detections suggest multiple areas
of frequent use by short-finned pilot whales in the Mariana Islands and
do not support that the areas west of Guam and Rota are key areas of
biological importance for short-finned pilot whales. Accordingly,
specific geographic mitigation measures, beyond the procedural measures
that reduce the likelihood of injury or more severe behavioral impacts
for short-finned pilot whales during all activities, is not warranted.
Comment 42: A Commenter recommended that NMFS should establish a
mitigation area to protect important habitat for multiple species of
marine mammals at Rota Bank, particularly as important habitat for
spinner and bottlenose dolphins and potential feeding habitat for
Bryde's whales.
Response: NMFS has considered the best available information for
this suggested mitigation area. As discussed in Appendix I (Geographic
Mitigation Assessment) of the 2020 MITT FSEIS/OEIS, there is
insufficient evidence to identify Rota Bank as an important area for
spinner dolphins or bottlenose dolphins and therefore additional
mitigation beyond the procedural measures that reduce impacts for all
species is not warranted. The Commenter notes the potentially higher
relative abundance of spinner dolphins in the area, as well as the
potential for a genetically distinct population of bottlenose dolphins.
However, spinner dolphins have also been sighted at multiple other
locations around the Marianas, including important resting habitat in
Agat Bay where NMFS has developed a geographic mitigation area, and the
Commenter includes no information to support why the identification of
a genetically distinct population of bottlenose dolphins in the
Marianas would support the
[[Page 46331]]
identification of a mitigation area at Rota Bank. Further, the single
sighting of a Bryde's whale feeding approximately five years ago does
not indicate the presence of an established feeding area for the
species.
During nine years of surveys from 2010-2018, spinner dolphins were
only sighted at Rota Bank on two years, 2011 and 2012 (Hill et al.,
2019). More sightings across all years occurred in shallow water less
than 100 m and within 1 km of land. Bottlenose dolphins, similar to
spinner dolphins, were only sighted at Rota Bank in 2011 and 2012.
Tracking of six bottlenose dolphins with attached satellite tags showed
wide variations in tag locations between northern Guam and Rota (tag
duration only 3.7-20.5 days). Only four Bryde's whale sightings in 2015
near Guam or Rota were reported based on small boat surveys from 2010-
2018. Only one of these four sightings was near, although not on, Rota
Bank. There were no other Bryde's whale sightings near Rota Bank in any
other year. Accordingly, specific geographic mitigation, beyond the
procedural measures that reduce the likelihood of injury or more severe
behavioral impacts for dolphins and all species during all activities,
is not warranted.
Other Mitigation and Monitoring
Comment 43: Based on the fact that the Commenter did not see
reference to the Navy's ongoing Lookout effectiveness study in the 2020
MITT FSEIS/OEIS and was concerned that the results of this 10-year
study would not be made available, they recommended that NMFS require
the Navy to (1) allocate additional resources to the Lookout
effectiveness study, (2) consult with the University of St. Andrews to
determine how much additional data is necessary to analyze the data in
a statistically significant manner, and (3) plan future Lookout
effectiveness cruises to maximize the potential number of sightings so
that the study can be completed by the end of 2022.
Response: NMFS has ensured that the results of the Lookout
effectiveness study will be made available by including a Term and
Condition in the ESA Incidental Take Statement associated with this
rule that requires the Navy to provide a report summarizing the status
of and/or providing a final assessment on the Navy's Lookout
Effectiveness Study following the end of Calendar Year (CY) 2021. The
report must be submitted no later than 90 days after the end of CY2021.
The report will provide a statistical assessment of the data available
to date characterizing the effectiveness of Navy Lookouts relative to
trained marine mammal observers for the purposes of implementing the
mitigation measures.
Comment 44: A Commenter recommends that NMFS require the Navy to
use passive and active acoustic monitoring (such as instrumented
ranges), whenever practicable, to supplement visual monitoring during
the implementation of its mitigation measures for all activities that
could cause injury or mortality beyond those explosive activities for
which passive acoustic monitoring already was proposed. At the very
least, the sonobuoys, active sources, and hydrophones used during an
activity should be monitored for marine mammals.
Response: The Navy does employ passive acoustic monitoring to
supplement visual monitoring when practicable to do so (i.e., when
assets that have passive acoustic monitoring capabilities are already
participating in the activity). We note, however, that sonobuoys have a
narrow band that does not overlap with the vocalizations of all marine
mammals, and there is no bearing or distance on detections based on the
number and type of devices typically used; therefore it is not possible
to use these to implement mitigation shutdown procedures. For explosive
events in which there are no platforms participating that have passive
acoustic monitoring capabilities, adding passive acoustic monitoring
capability, either by adding a passive acoustic monitoring device
(e.g., hydrophone) to a platform already participating in the activity
or by adding a platform with integrated passive acoustic monitoring
capabilities to the activity (such as a sonobuoy), for mitigation is
not practicable. As discussed in Section 5.6.3 (Active and Passive
Acoustic Monitoring Devices) of the 2020 MITT FSEIS/OEIS, which NMFS
reviewed and concurs accurately assesses the practicability of
utilizing additional passive or active acoustic systems for mitigation
monitoring, there are significant manpower and logistical constraints
that make constructing and maintaining additional passive acoustic
monitoring systems or platforms for each training and testing activity
impracticable. Additionally, diverting platforms that have passive
acoustic monitoring capability would impact their ability to meet their
Title 10 requirements and reduce the service life of those systems.
Regarding the use of instrumented ranges for real-time mitigation,
the Commenter is correct that the Navy continues to develop the
technology and capabilities on its Ranges for use in marine mammal
monitoring, which can be effectively compared to operational
information after the fact to gain information regarding marine mammal
response. There is no instrumented range in the MITT Study Area to use.
Further, the Navy's instrumented ranges were not developed for the
purpose of mitigation. The manpower and logistical complexity involved
in detecting and localizing marine mammals in relation to multiple
fast-moving sound source platforms in order to implement real-time
mitigation is significant. Although the Navy is continuing to improve
its capabilities to use range instrumentation to aid in the passive
acoustic detection of marine mammals, at this time it would not be
effective or practicable for the Navy to monitor instrumented ranges
for the purpose of real-time mitigation for the reasons discussed in
Section 5.6.3 (Active and Passive Acoustic Monitoring Devices) of the
2020 MITT FSEIS/OEIS.
Regarding the use of active sonar for mitigation, we note that
during Surveillance Towed Array Sensor System low-frequency active
sonar (which is not part of this rulemaking, and uses a high-powered
low frequency source), the Navy uses a specially designed adjunct high-
frequency marine mammal monitoring active sonar known as ``HF/M3'' to
mitigate potential impacts. HF/M3 can only be towed at slow speeds
(significantly slower than those used for ASW and the other training
and testing uses contemplated for the MITT activities) and operates
like a fish finder used by commercial and recreational fishermen.
Installing the HF/M3 adjunct system on the tactical sonar ships used
during activities in this rule would have implications for safety and
mission requirements due to impacts on speed and maneuverability.
Furthermore, installing the system would significantly increase costs
associated with designing, building, installing, maintaining, and
manning the equipment. For these reasons, installation of the HF/M3
system or other adjunct marine mammal monitoring devices as mitigation
under the rule would be wholly impracticable. Further, NMFS does not
generally recommend the use of active sonar for mitigation, except in
certain cases where there is a high likelihood of injury or mortality
(e.g., gear entanglement) and other mitigations are expected to be less
effective in mitigating those effects. Active sonar generates
additional noise with the potential to disrupt marine mammal
[[Page 46332]]
behavior, and is operated continuously during the activity that it is
intended to mitigate. On the whole, adding this additional stressor is
not beneficial unless it is expected to offset, in consideration of
other mitigations already being implemented, a high likelihood or
amount of injury or mortality. For the Navy's MITT activities,
mortality is not anticipated, injury is of a small amount of low-level
PTS, and the mitigation is expected to be effective at minimizing
impacts. Further, the species most likely to incur a small degree of
PTS from the Navy's activities are also the species with high frequency
sensitivity that would be more likely to be behaviorally disturbed by
the operation of the high frequency active source. For all of these
reasons, NMFS does not recommend the use of active sonar to mitigate
the Navy's training and testing activities in the MITT Study Area.
Comment 45: A Commenter asserted that given the apparent effect of
the post-model analysis on the agency's mortality estimates--accounting
perhaps for the drop in expected deaths from 150 (during the previous
five-year period) to virtually zero--NMFS should have made the Navy's
approach transparent and explained the rationale for its acceptance of
that approach. NMFS' failure to do so has prevented the public from
effectively commenting on NMFS' approach to this issue, in
contravention of the Administrative Procedure Act, on a matter of
obvious significance to the agency's core negligible impact findings.
Response: The Commenter is mistaken, there were no mortalities
modeled or authorized in the Phase II rulemaking (2015-2020) for the
MITT Study Area. Please see 80 FR 46112 (Aug. 3, 2015).
Comment 46: A Commenter recommended that NMFS consider additional
measures to address mitigation for explosive events at night and during
periods of low-visibility, either by enhancing the observation
platforms to include aerial and/or passive acoustic monitoring (such as
glider use), as has been done here with sinking exercises, or by
restricting events to particular Beaufort sea states (depending on
likely species presence and practicability). Another Commenter
complains that NMFS has not required aerial or passive acoustic
monitoring as mandatory mitigation, appears unwilling to restrict
operations in low-visibility conditions, and has set safety-zone bounds
that are inadequate to protect high-frequency cetaceans even from PTS.
Response: As described in Section 5.6.2 (Explosives) of the 2020
MITT FSEIS/OEIS, when assessing and developing mitigation, NMFS and the
Navy considered reducing the number and size of explosives and limiting
the locations and time of day of explosive training and testing in the
MITT Study Area. The locations and timing of the training and testing
activities that use explosives vary throughout the MITT Study Area
based on range scheduling, mission requirements, testing program
requirements, and standard operating procedures for safety and mission
success. Although activities using explosives typically occur during
daytime for safety reasons, it is impractical for the Navy to prohibit
every type of explosive activity at night or during low visibility
conditions or during different Beaufort sea states. Doing so would
diminish activity realism, which would impede the ability for Navy
Sailors to train and become proficient in using explosive weapons
systems (which would result in a significant risk to personnel safety
during military missions and combat operations), and would impede the
Navy's ability to certify forces to deploy to meet national security
needs.
Passive acoustic devices, whether vessel-deployed or using research
sensors on gliders or other devices, can serve as queuing information
that vocalizing marine mammals could be in the vicinity. Passive
acoustic detection does not account for individuals not vocalizing.
Navy surface ships train to localize submarines, not marine mammals.
Some aviation assets deploying ordnance do not have concurrent passive
acoustic sensors. Furthermore, Navy funded civilian passive acoustic
sensors do not report in real-time. Instead, a glider is set on a
certain path or floating/bottom-mounted sensor deployed. The sensor has
to then be retrieved often many months after deployment (1-8 months),
data is sent back to the laboratory, and then subsequently analyzed.
Combined with lack of localization, gliders with passive acoustic
sensors are therefore not suitable for mitigation. Further, a SINKEX is
a highly scripted event that due to its complexity has additional
assets involved that are not practicable to bring to bear in all the
smaller types of training and testing scenarios.
The Navy does employ passive acoustic monitoring when practicable
to do so (i.e., when assets that have passive acoustic monitoring
capabilities are already participating in the activity) and several of
the procedural mitigation measures reflect this, but many platforms do
not have passive acoustic monitoring capabilities. Adding a passive
acoustic monitoring capability (either by adding a passive acoustic
monitoring device (e.g., hydrophone) to a platform already
participating in the activity, or by adding a platform with integrated
passive acoustic monitoring capabilities to the activity, such as a
sonobuoy) for mitigation is not practicable. As discussed in Section
5.6.3 (Active and Passive Acoustic Monitoring Devices) of the 2020 MITT
FSEIS/OEIS, there are significant manpower and logistical constraints
that make constructing and maintaining additional passive acoustic
monitoring systems or platforms for each training and testing activity
impracticable. The Navy is required to implement pre-event observation
mitigation, as well as post-event observation when practical, for all
in-water explosive events. If there are other platforms participating
in these events and in the vicinity of the detonation area, they will
also visually observe this area as part of the mitigation team.
The Mitigation Section (Section 5) of the 2020 MITT FSEIS/OEIS
includes a full analysis discussion of the mitigation measures that the
Navy will implement, as well as those that have been considered but
eliminated, including potential measures that have been raised by NMFS
or the public in the past. The Navy has explained that training and
testing in both good visibility (e.g., daylight, favorable weather
conditions) and low visibility (e.g., nighttime, inclement weather
conditions) is vital because environmental differences between day and
night and varying weather conditions affect sound propagation and the
detection capabilities of sonar. Temperature layers that move up and
down in the water column and ambient noise levels can vary
significantly between night and day. This affects sound propagation and
could affect how sonar systems function and are operated. While some
small reduction in the probability or severity of impacts could result
from the implementation of this measure, it would not be practicable
for the Navy to restrict operations in low visibility and the measure
is not, therefore, warranted.
Regarding the safety zones for high frequency specialists, as the
Commenter notes, for some sources the zone in which PTS could be
accrued is larger than the mitigation zones. Because of the lower
injury thresholds for high frequency specialists, the zones within
which these species may incur PTS are significantly larger than other
groups, and for some of the louder or more powerful sources, the injury
zones are larger than can be effectively monitored
[[Page 46333]]
or practicably mitigated at distances beyond the established shutdown
zones. In all cases, the required exclusion zones will prevent injury
in the area closer to the source, thus alleviating some Level A
harassment and preventing more intense or longer duration exposures
that would be likely to have more severe impacts, and the small number
remaining of anticipated PTS has been evaluated in the negligible
impact analysis and appropriately authorized. In addition to the fact
that observance and implementation of larger mitigation zones is
impracticable, we also note that Navy Lookouts do not differentiate
species and therefore it would not be possible to effectively implement
a larger shutdown zone that only applied to the two high frequency
specialists (dwarf and pygmy sperm whales), especially at the distances
at which this differential mitigation would need to apply (beyond the
standard zones).
Comment 47: A Commenter recommended that sonar signals might be
modified to reduce the level of impact at the source. Mitigating active
sonar impacts might be achieved by employing down-sweeps with harmonics
or by reducing the level of side bands (or harmonics). The Commenter
strongly recommended that NMFS require and set a timeline for this
research within the context of the present rulemaking.
Response: The Commenter notes that NOAA's Ocean Noise Strategy
Roadmap puts an emphasis on source modification and habitat
modification as an important means for reducing impacts, however, where
the modification of sources is discussed, the focus of the Roadmap is
on modifying technologies for activities in which low frequency,
broadband sound (which contribute far more significantly to increased
chronic noise levels) is incidental to the activity (e.g., maritime
traffic). As described in the 2020 MITT FSEIS/OEIS, at this time, the
science on the differences in potential impacts of up or down sweeps of
the sonar signal (e.g., different behavioral reactions) is extremely
limited and requires further development before a determination of
potential mitigation effectiveness can be made. There is data on
behavioral responses of a few captive harbor porpoises to varying
signals. Although this very limited data set suggests up or down sweeps
of the sonar signal may result in different reactions by harbor
porpoises in certain circumstances, the author of those studies
highlights the fact that different species respond to signals with
varying characteristics in a number of ways. In fact, the same signals
cited here were also played to harbor seals, and their responses were
different from the harbor porpoises. Furthermore, harmonics in a signal
result from a high-intensity signal being detected in close proximity;
they could be artificially removed for a captive study, but cannot be
whitened in the open ocean. Active sonar signals are designed
explicitly to provide optimum performance at detecting underwater
objects (e.g., submarines) in a variety of acoustic environments. If
future studies indicate that modifying active sonar signals could be an
effective mitigation approach, then NMFS with the Navy will investigate
if and how the mitigation would affect the sonar's performance and how
that mitigation may be applied in future authorizations, but currently
NMFS does not have a set timeline for this research and how it may be
applied to future rulemakings.
Comment 48: A Commenter recommends that NMFS should consider
requiring the Navy to employ thermal detection in optimal conditions,
or, alternatively, require the establishment of a pilot program for
thermal detection, with annual review under the adaptive management
system. According to the 2019 MITT DSEIS/OEIS, the Navy ``plans to
continue researching thermal detection technology to determine their
effectiveness and compatibility with Navy applications.''
Response: Thermal detection systems are more useful for detecting
marine mammals in some marine environments than others. Current
technologies have limitations regarding water temperature and survey
conditions (e.g., rain, fog, sea state, glare, ambient brightness), for
which further effectiveness studies are required. Thermal detection
systems are generally thought to be most effective in cold
environments, which have a large temperature differential between an
animal's temperature and the environment. Current thermal detection
systems have proven more effective at detecting large whale blows than
the bodies of small animals, particularly at a distance. The
effectiveness of current technologies has not been demonstrated for
small marine mammals. Research to better understand, and improve,
thermal technology continues, as described below.
The Navy has been investigating the use of thermal detection
systems with automated marine mammal detection algorithms for future
mitigation during training and testing, including on autonomous
platforms. Thermal detection technology being researched by the Navy,
which is largely based on existing foreign military grade hardware, is
designed to allow observers and eventually automated software to detect
the difference in temperature between a surfaced marine mammal (i.e.,
the body or blow of a whale) and the environment (i.e., the water and
air). Although thermal detection may be reliable in some applications
and environments, the current technologies are limited by their: (1)
Low sensor resolution and a narrow fields of view, (2) reduced
performance in certain environmental conditions, (3) inability to
detect certain animal characteristics and behaviors, and (4) high cost
and uncertain long-term reliability.
Thermal detection systems for military applications are deployed on
various Department of Defense (DoD) platforms. These systems were
initially developed for night time targeting and object detection
(e.g., a boat, vehicle, or people). Existing specialized DoD infrared/
thermal capabilities on Navy aircraft and surface ships are designed
for fine-scale targeting. Viewing arcs of these thermal systems are
narrow and focused on a target area. Furthermore, sensors are typically
used only in select training events, not optimized for marine mammal
detection, and have a limited lifespan before requiring expensive
replacement. Some sensor elements can cost upward of $300,000 to
$500,000 per device, so their use is predicated on a distinct military
need.
One example of trying to use existing DoD thermal systems is being
proposed by the U.S. Air Force. The Air Force agreed to attempt to use
specialized U.S. Air Force aircraft with military thermal detection
systems for marine mammal detection and mitigation during a limited at-
sea testing event. It should be noted, however, these systems are
specifically designed for and integrated into a small number of U.S.
Air Force aircraft and cannot be added or effectively transferred
universally to Navy aircraft. The effectiveness remains unknown in
using a standard DoD thermal system for the detection of marine mammals
without the addition of customized system-specific computer software to
provide critical reliability (enhanced detection, cueing for an
operator, reduced false positive, etc.)
Current DoD thermal sensors are not always optimized for marine
mammal detections versus object detection, nor do these systems have
the automated marine mammal detection algorithms the Navy is testing
via its ongoing research program. The combination of thermal technology
and automated algorithms are still undergoing demonstration and
validation under Navy funding.
[[Page 46334]]
Thermal detection systems specifically for marine mammal detection
have not been sufficiently studied both in terms of their effectiveness
within the environmental conditions found in the MITT Study Area and
their compatibility with Navy training and testing (i.e., polar waters
vs. temperate waters). The effectiveness of even the most advanced
thermal detection systems with technological designs specific to marine
mammal surveys is highly dependent on environmental conditions, animal
characteristics, and animal behaviors. At this time, thermal detection
systems have not been proven to be more effective than, or equally
effective as, traditional techniques currently employed by the Navy to
observe for marine mammals (i.e., naked-eye scanning, hand-held
binoculars, high-powered binoculars mounted on a ship deck). The use of
thermal detection systems instead of traditional techniques would
compromise the Navy's ability to observe for marine mammals within its
mitigation zones in the range of environmental conditions found
throughout the MITT Study Area. Furthermore, thermal detection systems
are designed to detect marine mammals and do not have the capability to
detect other resources for which the Navy is required to implement
mitigation, including sea turtles. Focusing on thermal detection
systems could also provide a distraction from and compromise the Navy's
ability to implement its established observation and mitigation
requirements. The mitigation measures discussed in the Mitigation
Measures section include the maximum number of Lookouts the Navy can
assign to each activity based on available manpower and resources;
therefore, it would be impractical to add personnel to serve as
additional Lookouts. For example, the Navy does not have available
manpower to add Lookouts to use thermal detection systems in tandem
with existing Lookouts who are using traditional observation
techniques.
The Defense Advanced Research Projects Agency funded six initial
studies to test and evaluate infrared-based thermal detection
technologies and algorithms to automatically detect marine mammals on
an unmanned surface vehicle. Based on the outcome of these initial
studies, the Navy is pursuing additional follow-on research efforts.
Additional studies are currently being planned for 2020+ but additional
information on the exact timing and scope of these studies is not
currently available (still in the development stage).
The Office of Naval Research Marine Mammals and Biology program
also funded a project (2013-2019) to test the thermal limits of
infrared-based automatic whale detection technology. That project
focused on capturing whale spouts at two different locations featuring
subtropical and tropical water temperatures, optimizing detector/
classifier performance on the collected data, and testing system
performance by comparing system detections with concurrent visual
observations. Results indicated that thermal detection systems in
subtropical and tropical waters can be a valuable addition to marine
mammal surveys within a certain distance from the observation platform
(e.g., during seismic surveys, vessel movements), but have challenges
associated with false positive detections of waves and birds (Boebel,
2017). While Zitterbart et al. (2020) reported on the results of land-
based thermal imaging of passing whales, their conclusion was that
thermal technology under the right conditions and from land can detect
a whale within 3 km although there could also be lots of false
positives, especially if there are birds, boats, and breaking waves at
sea. Thermal detection systems exhibit varying degrees of false
positive detections (i.e., incorrect notifications) due in part to
their low sensor resolution and reduced performance in certain
environmental conditions. False positive detections may incorrectly
identify other features (e.g., birds, waves, boats) as marine mammals.
In one study, a false positive rate approaching one incorrect
notification per 4 min of observation was noted.
The Navy plans to continue researching thermal detection systems
for marine mammal detection to determine their effectiveness and
compatibility with Navy applications. If the technology matures to the
state where thermal detection is determined to be an effective
mitigation tool during training and testing, NMFS and the Navy will
assess the practicability of using the technology during training and
testing events and retrofitting the Navy's observation platforms with
thermal detection devices. The assessment will include an evaluation of
the budget and acquisition process (including costs associated with
designing, building, installing, maintaining, and manning the
equipment); logistical and physical considerations for device
installment, repair, and replacement (e.g., conducting engineering
studies to ensure there is no electronic or power interference with
existing shipboard systems); manpower and resource considerations for
training personnel to effectively operate the equipment; and
considerations of potential security and classification issues. New
system integration on Navy assets can entail up to 5 to 10 years of
effort to account for acquisition, engineering studies, and development
and execution of systems training. The Navy will provide information to
NMFS about the status and findings of Navy-funded thermal detection
studies and any associated practicability assessments at the annual
adaptive management meetings.
Evidence regarding the current state of this technology does not
support the assertion that the addition of these devices would
meaningfully increase detection of marine mammals beyond the current
rate (especially given the narrow field of view of this equipment and
the fact that a Lookout cannot use standard equipment when using the
thermal detection equipment) and, further, modification of standard
Navy equipment, training, and protocols would be required to integrate
the use of any such new equipment, which would incur significant cost.
At this time, requiring thermal equipment is not warranted given the
prohibitive cost and the uncertain benefit (i.e., reduction of impacts)
to marine mammals. Likewise requiring the establishment of a pilot
program is not appropriate. However, as noted above, the Navy continues
to support research and technology development to improve this
technology for potential future use.
Comment 49: A Commenter stated that the proposed rule does not
contain any indication that a practicability analysis was conducted,
nor does it prescribe any speed reduction measure. They ask that NMFS
conduct a practicability analysis and implement vessel speed reduction
in (at minimum) the Marpi Reef and Chalan Kanoa Reef Mitigation Areas
and other areas of importance to humpback whales, as was done for the
North Atlantic right whale in the AFTT Study Area. They further
recommended that the agency require the Navy to collect and report data
on ship speed to allow for objective evaluation by NMFS of ship-strike
risk, of harassment resulting from vessel activity, and of the
potential benefit of additional speed-focused mitigation measures.
Response: NMFS discussed its evaluation of requiring vessel speed
restrictions in Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
Areas in Comment 17 above. NMFS and the Navy conducted an operational
analysis of potential mitigation areas throughout
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the entire MITT Study Area to consider a wide range of mitigation
options, including but not limited to vessel speed restrictions. Navy
ships transit at speeds that are optimal for fuel conservation or to
meet operational requirements. In our assessment of potential
mitigation, NMFS and the Navy have considered implementing vessel speed
restrictions. However, as described in Section 5 (Mitigation), Section
5.3.4.1 (Vessel Movement) of the 2020 MITT FSEIS/OEIS, including vessel
speed restrictions would be impracticable due to implications for
safety (the ability to avoid potential hazards), sustainability
(maintain readiness), and the Navy's ability to continue meeting its
Title 10 requirements to successfully accomplish military readiness
objectives. Any vessel speed restrictions would prevent vessel
operators from gaining skill proficiency, would prevent the Navy from
properly testing vessel capabilities, and/or would increase the time on
station during training or testing activities as required to achieve
skill proficiency or properly test vessel capabilities, which would
significantly increase fuel consumption. NMFS thoroughly reviewed and
considered the information and analysis in the 2020 MITT FSEIS/OEIS,
and concurred with the Navy's determination that vessel speed
restrictions are impracticable. As discussed in the Mitigation Measures
section of this rule, the Navy will implement mitigation to avoid
vessel strikes throughout the Study Area. Given the impracticability of
vessel speed restrictions combined with the fact that vessel strike is
not anticipated in the MITT Study Area and that the required mitigation
for vessel movement will already minimize any potential for ship
strike, NMFS finds vessel speed reductions are not warranted.
As required through the Navy's Notification and Reporting Plan
(Vessel Strike section), Navy vessels are required to report extensive
information, including ship speed, pursuant to any marine mammal vessel
strikes. Therefore, the data required for ship strike analysis
discussed in the comment is already being collected. Any additional
data collection requirement would create an unnecessary burden on the
Navy.
Regarding vessel noise from Navy ships, Navy vessels are
intentionally designed to be quieter than civilian vessels, and given
that adverse impacts from vessel noise are not anticipated to result
from Navy activities (see the Potential Effects of Specified Activities
on Marine Mammals and Their Habitat section in the proposed rule),
there is no anticipated harassment caused by vessel activity and
therefore no need to collect and report data on ship speed for this
purpose.
Comment 50: A Commenter recommended that NMFS should consider a
compensatory mitigation scheme to help improve the conservation status
or habitat of affected populations. NMFS should consider requiring
compensatory mitigation for the adverse impacts of the Navy's activity
on marine mammals and their habitat that cannot be prevented or
mitigated.
Response: Compensatory mitigation is not required under the MMPA.
Instead, authorizations include means of effecting the least
practicable adverse impact from the activities on the affected species
or stocks and their habitat, which this rule has done through the
required procedural and geographic area mitigation measures.
For years, the Navy has implemented a broad and comprehensive range
of measures in the MITT Study Area to mitigate potential impacts to
marine mammals from its training and testing activities. In addition,
from 2010 and ongoing, the Navy has funded extensive marine mammal
occurrence studies within the Mariana Islands. As described in this
rule, NMFS and the Navy have expanded these measures further where
practicable. In addition to the mitigation and monitoring measures
required under this rule and past MMPA incidental take authorizations,
the Navy engages in an extensive spectrum of other activities that
greatly benefit marine species in a more general manner that is not
necessarily tied to just military readiness activities. As noted in
Section 3, Section 3.0.1.1 (Marine Species Monitoring and Research
Programs) of the 2020 MITT FSEIS/OEIS, the Navy provides extensive
investment for research programs in basic and applied research. The
Navy is one of the largest sources of funding for marine mammal
research in the world, which has greatly enhanced the scientific
community's understanding of marine species more generally. The Navy's
support of marine mammal research includes: Marine mammal detection,
including the development and testing of new autonomous hardware
platforms and signal processing algorithms for detection,
classification, and localization of marine mammals; improvements in
density information and development of abundance models of marine
mammals; and advancements in the understanding and characterization of
the behavioral, physiological (hearing and stress response), and
potentially population-level consequences of sound exposure on marine
life. Importantly, the Commenter did not recommend any specific
measures, rendering it impossible to consider its recommendation at a
broader level.
Comment 51: A Commenter recommends that NMFS require that the Navy
continue to conduct long-term monitoring and prioritize Navy research
projects that aim to quantify the impact of training and testing
activities at the individual, and ultimately, population-level. The
Commenter recommended individual-level behavioral-response studies,
such as focal follows and tagging using DTAGs, carried out before,
during, and after Navy operations, that can provide important insights
for these species and stocks. The Commenter recommended studies be
prioritized that further characterize the suite of vocalizations
related to social interaction, such as studies using DTAGs that further
characterize social communications between individuals of a species or
stock, including between mothers and calves. The Commenter recommends
the use of unmanned aerial vehicles for surveying marine species and to
provide a less invasive approach to undertaking focal follows. Imagery
from unmanned aerial vehicles can also be used to assess body condition
and, in some cases, health of individuals. The Commenter recommended
that NMFS require the Navy to use these technologies for assessing
marine mammal behavior (e.g., swim speed and direction, group cohesion)
before, during, and after Navy training and testing. Additionally, the
Commenter recommended that the Navy support studies to explore how
these technologies can be used to assess body condition, as this can
provide an important indication of energy budget and health, which can
inform the assessment of population-level impacts.
Response: First, the Navy is pursuing many of the topics that the
Commenter identifies, either through the monitoring required under the
MMPA or monitoring under the ESA, or through other Navy-funded research
programs (ONR and LMR). We are confident that the monitoring conducted
by the Navy satisfies the requirements of the MMPA. A list of the
monitoring studies that the Navy will be conducting under this rule is
at the end of the Monitoring section of this final rule.
Broadly speaking, in order to ensure that the monitoring the Navy
conducts satisfies the requirements of the MMPA, NMFS works closely
with the Navy in the identification of monitoring priorities and the
selection of projects to
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conduct, continue, modify, and/or stop through the Adaptive Management
process, which includes annual review and debriefs by all scientists
conducting studies pursuant to the MMPA authorization. The process NMFS
and the Navy have developed allows for comprehensive and timely input
from NMFS, the Navy, the Marine Mammal Commission, and researchers
conducting monitoring under the Navy rule, which is based on rigorous
reporting out from the Navy and the researchers doing the work.
With extensive input from NMFS, the Navy established the Strategic
Planning Process for Marine Species Monitoring to help structure the
evaluation and prioritization of projects for funding. The Monitoring
section of this rule provides an overview of this Strategic Planning
Process. More detail, including the current intermediate scientific
objectives, is available in section 5 (Mitigation), Section 5.1.2.2.1.3
(Strategic Planning Process) of the 2020 MITT FSEIS/OEIS and on the
monitoring portal as well as in the Strategic Planning Process report.
The Navy's evaluation and prioritization process is driven largely by a
standard set of criteria that help the internal steering committee
evaluate how well a potential project would address the primary
objectives of the monitoring program. Given that the Navy's Monitoring
Program applies to all of the Navy's major Training and Testing
activities and, thereby, spans multiple regions and Study Areas to
encompass consideration of the entire U.S. EEZ and beyond, one of the
key components of the prioritization process is to focus monitoring in
a manner that fills regionally-specific data gaps, where possible
(e.g., more limited basic marine mammal distribution data in the MITT
Study Area), and also takes advantage of regionally-available assets
(e.g., instrumented ranges in the HSTT Study Area). NMFS has
opportunities to provide input regarding the Navy's intermediate
scientific objectives as well as to provide feedback on individual
projects through the annual program review meeting and annual report.
For additional information, please visit: https://www.navymarinespeciesmonitoring.us/about/strategic-planning-process/.
Details on the Navy's involvement with future research will
continue to be developed and refined by the Navy and NMFS through the
consultation and adaptive management processes, which regularly
consider and evaluate the development and use of new science and
technologies for Navy applications. Further, the Navy also works with
NMFS to target and prioritize data needs that are more appropriately
addressed through Navy research programs, such as the Office of Naval
Research and Living Marine Resources programs. The Navy has indicated
that it will continue to be a leader in funding of research to better
understand the potential impacts of Navy training and testing
activities and to operate with the least possible impacts while meeting
training and testing requirements. Some of the efforts the Navy is
leading or has recently completed are described below.
(1) Individual-level behavioral-response studies--There are no ONR
or LMR behavioral response studies in the MITT Study Area. The Mariana
Islands are too remote for many of the mainland U.S. and international
researchers. There is also insufficient background information or
infrastructure to support something as specific as a behavioral
response study. For example, Navy instrumented ranges in the HSTT Study
Area and the Bahamas are critical in providing consistent beaked whale
detections which allow researchers in small boats to more efficiently
locate detected whales to apply satellite tracking tags. However, many
of the studies on species-specific reactions are likely to be
applicable across geographic boundaries (e.g., Cuvier's beaked whale
studies in the HSTT Study Area).
(2) Tags and other detection technologies to characterize social
communication between individuals of a species or stock, including
mothers and calves--DTAGs are just one example of animal movement and
acoustics tag. From the Navy's Office of Naval Research and Living
Marine Resource programs, Navy funding is being used to improve a suite
of marine mammal tags to increase attachment times, improve data being
collected, and improve data satellite transmission. The Navy has funded
a variety of projects that are collecting data that can be used to
study social interactions amongst individuals. For example, as of July
2020 the following studies are currently being funded:
Assessing performance and effects of new integrated
transdermal large whale satellite tags 2018-2021 (Organization: Marine
Ecology and Telemetry Research)
Autonomous Floating Acoustic Array and Tags for Cue Rate
Estimation 2019-2020 (Organization: Texas A&M University Galveston)
Development of the next generation automatic surface whale
detection system for marine mammal mitigation and distribution
estimation 2019-2021 (Organization: Woods Hole Oceanographic
Institution)
High Fidelity Acoustic and Fine-scale Movement Tags 2016-2020
(Organization: University of Michigan)
Improved Tag Attachment System for Remotely-deployed Medium-
term Cetacean Tags 2019-2023 (Organization: Marine Ecology and
Telemetry Research)
Next generation sound and movement tags for behavioral studies
on whales 2016-2020 (Organization: University of St. Andrews)
On-board calculation and telemetry of the body condition of
individual marine mammals 2017-2021 (Organization: University of St.
Andrews, Sea Mammal Research Unit)
The wide-band detection and classification system 2018-2020
(Organization: Woods Hole Oceanographic Institution)
(3) Unmanned Aerial Vehicles to assess marine mammal behavior
(e.g., swim speed and direction, group cohesion) before, during, and
after Navy training and testing activities--Studies that use unmanned
aerial vehicles to assess marine mammal behaviors and body condition
are being funded by the Office of Naval Research Marine Mammals and
Biology program. Although the technology shows promise (as reviewed by
Verfuss et al., 2019), the field limitations associated with the use of
this technology have hindered its useful application in behavioral
response studies in association with Navy training and testing events.
For safety, research vessels cannot remain in close proximity to Navy
vessels during Navy training or testing events, so battery life of the
unmanned aerial vehicles has been an issue. However, as the technology
improves, the Navy will continue to assess the applicability of this
technology for the Navy's research and monitoring programs. An example
project that the Navy already addressed is integrating remote sensing
methods to measure baseline behavior and responses of social delphinids
to Navy sonar 2016-2019 (Organization: Southall Environmental
Associates Inc.).
(4) Modeling methods that could provide indicators of population-
level effects--NMFS asked the Navy to expand funding to explore the
utility of other, simpler modeling methods that could provide at least
an indicator of population-level effects, even if each of the
behavioral and physiological mechanisms are not fully characterized.
The Office of Naval Research Marine Mammals and Biology program has
invested in the Population
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Consequences of Disturbance (PCoD) model, which provides a theoretical
framework and the types of data that would be needed to assess
population level impacts. Although the process is complicated and many
species are data poor, this work has provided a foundation for the type
of data that is needed. Therefore, in the future, the relevant data
pieces that are needed for improving the analytical approaches for
population level consequences resulting from disturbances will be
collected during projects funded by the Navy's marine species
monitoring program. However, currently, PCoD models are dependent on
too many unknown factors to produce a reliable answer for most species
and activity types, and further work is needed (and underway) to
develop a more broadly applicable generalized construct that can be
used in an impact assessment.
As discussed in the Monitoring section of the final rule, the
Navy's marine species monitoring program typically supports 10-15
projects in the Pacific at any given time. Current projects cover a
range of species and topics from collecting baseline data on occurrence
and distribution, to tracking whales, to conducting behavioral response
studies on beaked whales and pilot whales. The Navy's marine species
monitoring web portal provides details on past and current monitoring
projects, including technical reports, publications, presentations, and
access to available data and can be found at: https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/.
In summary, NMFS and the Navy work closely together to prioritize,
review, and adaptively manage the extensive suite of monitoring that
the Navy conducts in order to ensure that it satisfies the MMPA
requirements. NMFS has laid out a broad set of goals that are
appropriate for any entity authorized under the MMPA to pursue, and
then we have worked with the Navy to manage their projects to best
target the most appropriate goals given their activities, impacts, and
assets in the MITT Study Area. Given the scale of the MITT Study Area
and the variety of activities conducted, there are many possible
combinations of projects that could satisfy the MMPA standard for the
rule. The Commenter has recommended more and/or different monitoring
than NMFS is requiring and the Navy is conducting or currently plans to
conduct, but has in no way demonstrated that the monitoring currently
being conducted does not satisfy the MMPA standard. NMFS appreciates
the Commenter's input, and will consider it, as appropriate, in the
context of our adaptive management process, but is not recommending any
changes at this time.
Comment 52: A Commenter recommended that the Navy conduct research
and documentation of the residency of populations of spinner dolphins
on Guam and impacts of the training to them. The Commenter states that
these populations may particularly be impacted by the mine explosion
training in areas at Agat and Asan. The Commenter recommends that the
Navy provide better information on the impacts of the explosions on
these populations before implementing the training at those sites. The
Commenter recognizes and supports that an area frequented by the Agat
spinner dolphins is identified as a mitigation area (mostly in National
Park Service managed waters) because of their presence.
Response: The Navy has been funding the majority of marine species
research and surveys in the Mariana Islands. Over a nine year period
from 2010-2018 during the Navy-funded small boat surveys in the Mariana
Islands, 22,488 km of on-effort surveys were conducted with 157
encounters with pods of spinner dolphins (Hill et al., 2019). The
approximate distance from shore for these encounters was 1 km,
indicative of their preference for nearshore habitat and prevalence in
the MITT Study Area (Hill et al., 2017a; Hill et al., 2018b; Hill et
al., 2019). In addition to visual sightings, a photo-identification
catalog for spinner dolphins was developed as well as biopsies taken
for genetic analysis (Hill et al., 2019). The Navy has also contributed
significant funding for NMFS' Pacific Marine Assessment Program for
Protected Species (PACMAPPS) program. PACMAPPS is a partnership among
Federal agencies to conduct surveys to assess the abundance of multiple
species and their ecosystems (NOAA Fisheries, U.S. Navy, Bureau of
Ocean Energy Management, U.S. Fish and Wildlife Service). With Navy
funding, NMFS will conduct a 60-day marine mammal survey within the
Mariana Island EEZ in the spring and summer of 2021. Future Mariana
Islands marine mammal surveys after PACMAPPs will be funded by NMFS'
Pacific Islands Fisheries Science Center. For an extensive discussion
of spinner dolphin sightings near Agat Bay, see Section I.3.3.1.1.1 of
the 2020 MITT FSEIS/OEIS.
Regarding the impacts of explosives, activities, including mine
countermeasure activities at the Agat Bay and Apra Harbor sites, were
modeled to estimate impacts on marine mammals from explosives. No
mortalities of any marine mammals are predicted. Asan is not identified
as an underwater detonation area. Further, although called Agat Bay
Mine Neutralization Site, the actual detonation site is in waters
deeper than 1,000 m and over 8 km west of the shallow water Agat Bay
Nearshore Geographic Mitigation Area (see Figure 3 of this rule) and
therefore there is not a potential for overlap of explosive activities
at the Agat Bay Mine Neutralization Site with spinner dolphin resting.
Additionally, the Navy uses the Agat Bay Mine Neutralization Site for
smaller charge weight mine neutralization activities that are episodic
with large temporal variation between successive events. In
consideration of the mine neutralization mitigations established for
all marine mammals (see the Procedural Mitigation subsection in the
Mitigation Measures section of the rule) and the distance between the
actual detonation site and the shallow water spinner dolphin habitat in
Agat Bay, the effects to spinner dolphins will be minimal.
Negligible Impact Determination
Comment 53: A Commenter asserts that most of NMFS' discussion
consists, once again, of generalized statements meant to suggest why
the estimated levels of take will not result in greater than negligible
impacts on marine mammals. For example, NMFS discounts the potential
for population-level impacts by asserting that based on the nature of
the Navy activities and the movement patterns of marine mammals, it is
unlikely any particular subset would be taken over more than a few
sequential days 85 FR 5875. Yet NMFS presents no details of the Navy's
operations in support of this position. Further a Commenter says that
the proposed rule makes no attempt to apply any of the methods used by
the marine mammal research community to assess population-level harm.
Such methods, involving quantitative or detailed qualitative
assessment, include but are not limited to the use of reasonable
proxies for population-level impact; models of masking effects;
energetic models, such as on foraging success; or quantitative
assessments of chronic noise or stress. The Commenter asserts that the
agency does not consider the effects of these more frequent exposures
on individual and population fitness, nor, again, does NMFS provide
more than general statements discounting the significance of the
expected take.
Response: NMFS fully considered the potential for aggregate effects
from all Navy activities and the Commenter
[[Page 46338]]
offers no evidence to support the assertion that any individual marine
mammals, of any species, would be subject to ``frequent exposures.''
NMFS has explained in detail in the proposed rule and again in this
final rule how the estimated takes were calculated for marine mammals,
and then how the large size of the Study Area across which activities
may be distributed (and the ASW activities utilizing MF1 sonar, which
account for the majority of the takes may occur anywhere in the Study
Area and predominantly more than 3 nmi from shore) combined with the
comparatively small number of takes as compared to the abundance of any
species in the area does not support that any individuals would likely
be taken over more than a few non-sequential days. We also consider
UMEs (where applicable) and previous environmental impacts, where
appropriate, to inform the baseline levels of both individual health
and susceptibility to additional stressors, as well as stock status.
Further, the species-specific assessments in the Analysis and
Negligible Impact Determination section pull together and address the
combined injury, behavioral disturbance, and other effects of the
aggregate MITT activities (and in consideration of applicable
mitigation) as well as other information that supports our
determinations that the Navy activities will not adversely affect any
species via impacts on rates of recruitment or survival. We refer the
reader to the Analysis and Negligible Impact Determination section for
this analysis. NMFS has described and applied a reasoned and
comprehensive approach to evaluating the effects of the Navy activities
on marine mammal species and their habitat. The Commenter cites various
articles in which one analytical approach or another was used to
evaluate particular scenarios or impacts, with no explanation of why
those methods are more appropriate or applicable.
Regarding the assertion that NMFS does not adequately consider
stress responses in its analysis, NMFS does not assume that the impacts
are insignificant. However, there is currently neither adequate data
nor a mechanism by which the impacts of stress from acoustic exposure
can be reliably and independently quantified. Stress effects that
result from noise exposure likely often occur concurrently with Level B
harassment (behavioral disturbance) and many are likely captured and
considered in the quantification of other takes by harassment that
occur when individuals come within a certain distance of a sound source
(behavioral disturbance, PTS, and TTS). The effects of these takes were
fully evaluated in the Analysis and Negligible Impact Determination
section.
Comment 54: A Commenter asserted that counter to NMFS' assertion
that no evidence of population-level consequences exists, an apparent
beaked whale population sink is observed on the AUTEC range (in the
Bahamas), attributed to the high levels of cumulative noise exposure at
the site. They further assert that similar concerns have focused
attention on resident beaked whale populations on the Navy's SOCAL
range, which exhibit strenuous responses to mid-frequency sonar
notwithstanding their repeated exposure.
Response: It is incorrect to conclude that there is a ``population
sink'' on the Navy's AUTEC range. In the citation provided (Claridge,
2013), that statement is merely a hypothesis, yet to be demonstrated.
When considering the portion of the beaked whale population within the
SOCAL portion of the HSTT Study Area and as presented in the 2018 HSTT
final rule and the 2018 HSTT FEIS/OEIS, multiple studies have
documented continued high abundance of beaked whales and the long-term
residency of documented individual beaked whales, specifically where
the Navy has been training and testing for decades (see for example
Debich et al., 2015a, 2015b; Dimarzio et al., 2018, 2020; Falcone and
Schorr, 2012, 2014, 2018, 2020; Hildebrand et al., 2009; Moretti, 2016;
[Scaron]irovi[cacute] et al., 2016; Smultea and Jefferson, 2014). There
is no evidence that there have been any population-level impacts to
beaked whales resulting from Navy training and testing in the SOCAL
portion of the HSTT Study Area. Importantly, no resident beaked whale
populations have been identified in the MITT Study Area, and both the
level of activities and the magnitude and severity of associated
impacts on beaked whales are lower than in the HSTT Study Area.
Comment 55: A Commenter stated that NMFS has not apparently
considered the impact of Navy activities on a population basis for many
of the marine mammal populations within the MITT Study Area. Instead,
it has lodged discussion for many populations within broader
categories, most prominently mysticetes and odontocetes, that in some
cases correspond to general taxonomic groups. Such grouping of stocks
elides important differences in abundance, demography, distribution,
and other population-specific factors, making it difficult to assume
``that the effects of an activity on the different stock populations''
are identical. Conservation Council, 97 F.Supp.3d at 1223. That is
particularly true where small, resident populations are concerned, and
differences in population abundance, habitat use, and distribution
relative to Navy activities can be profoundly significant.
Response: The Commenter erroneously suggests that NMFS makes
findings specific only to the level of Odontocetes and Mysticetes or
other general taxonomic groups, which is clearly inaccurate. NMFS first
provides information regarding broader groups (such as Mysticetes or
Odontocetes) in order to avoid repeating information that is applicable
across multiple species (or stocks if applicable), but analyses have
been conducted and determinations made specific to each species. Thus
we avoid repeating information applicable to a broader taxonomic group
or number of species (or stocks where applicable), while also
presenting and integrating all information needed to support the
negligible impact determination for a particular species (where no
stock information is available). We note that in the MITT Study Area,
species have not been assigned to stocks and there is little or no
information at the stock level. Please refer to the Analysis and
Negligible Impact Determination section of this final rule.
Comment 56: A Commenter asserted that NMFS assumes that all of the
Navy's estimated impacts would not affect individuals or populations
through repeated activity--even though the takes anticipated each year
would affect the same populations and, indeed, would admittedly involve
extensive use of some of the same biogeographic areas. And, the
Commenter asserts, while NMFS states that behavioral harassment (aside
from that caused by masking effects) involves a stress response that
may contribute to an animal's allostatic load, it assumes without
further analysis that any such impacts would be insignificant. The
Commenter further asserts that both statements are factually
insupportable given the lack of any substantial population analysis or
quantitative assessment of long-term effects in the proposed rule, in
addition to the numerous deficiencies in the thresholds and modeling
that NMFS has adopted from the Navy.
Response: As previously discussed, Navy activities are spread out
in the offshore waters around these islands, most activities are unit
level events which have relatively small footprints of tens of
kilometers resulting in small percentages of overall habitat affected
at
[[Page 46339]]
any one time, activities that use sonar or explosives are not conducted
every day of the year (active sonar use has traditionally been used on
20 percent of days or less, as reported through the CNA analysis of
beaked whale strandings), and even within a day sonar use during an
activity is intermittent (1 ping every 50 seconds) and often for short
duration periods (minutes to up to a few hours at a time). The impacts
of stress have been considered in NMFS' assessment (see the Potential
Effects of Specified Activities on Marine Mammals and Their Habitat
section of the proposed rule) and are also addressed in the response to
Comment 53 above. Regarding the take of marine mammals across the
multiple years of the rule, NMFS has found that in each of the seven
years of the rule (in which no individuals of any species are expected
to be taken on more than a few non-sequential days), the authorized
take is not expected to affect the reproductive success or survivorship
of any individual marine mammal. Given the lack of any impacts on the
reproduction or survival of any affected individuals, there will be no
effects on any species' annual rates of recruitment or survival in any
year, and therefore no basis to suggest that impacts would accrue over
the seven years of the rule in a manner that would have a non-
negligible impact on an affected species.
Comment 57: A Commenter stated that NMFS does not consider the
potential for acute synergistic effects from multiple activities taking
place at one time, as happens during major exercises or from Navy
activities in combination with other actions. For example, the agency
does not consider the greater susceptibility to vessel strike of
animals that have been temporarily harassed or disoriented, nor does
NMFS consider (for example) the synergistic effects of noise with other
stressors in producing or magnifying a stress response. This lack of
analysis is not supportable under the MMPA. Without an accurate
assessment of existing threats to marine mammals, NMFS lacks a
sufficient environmental baseline to determine whether the Navy's
action will have more than a negligible impact on marine mammal species
and stocks.
Response: NMFS did analyze the potential for aggregate effects from
mortality, injury, masking, habitat effects, energetic costs, stress,
hearing loss, and behavioral disturbance from the Navy's activities in
reaching the negligible impact determinations. The modeling for MTEs
and all activities includes the accumulated energy of all sonar sources
and stressors. Outside of MTEs or some or the larger coordinated
events, it is unlikely for several unit level activities to be
conducted in the same day in the same location/time to produce
aggregate effects on an individual. Further, we have explicitly
discussed the potential interaction of an individual being impacted by
TTS and behavioral disturbance simultaneously. We refer the reader to
the Analysis and Negligible Impact Determination section of the final
rule for the discussion on the potential for aggregate effects of the
Navy's activities on individuals as well as how these effects on
individuals relate to potential effects on annual rates of recruitment
and survival for each species.
In addition, NMFS fully considers the potential for aggregate/
synergistic effects from all Navy activities. We also consider UMEs
(when applicable) and previous environmental impacts, where
appropriate, to inform the baseline levels of both individual health
and susceptibility to additional stressors, as well as species/stock
status. Further, the species assessments in the Analysis and Negligible
Impact Determination section (which have been updated and expanded for
some species, i.e., humpback whales and beaked whales) pull together
and address the combined potential mortality, injury, behavioral
disturbance, and other effects of the aggregate MITT activities (and in
consideration of applicable mitigation measures) as well as additional
information from the Potential Effects of Specified Activities on
Marine Mammals and Their Habitat and Estimated Take of Marine Mammals
sections to support our determinations that the Navy activities will
not adversely affect any species via impacts on rates of recruitment or
survival. We refer the reader to the Analysis and Negligible Impact
Determination section for this analysis.
Widespread, extensive monitoring since 2006 on Navy ranges that
have been used for training and testing for decades has demonstrated no
evidence of population-level impacts. Based on the best available
science, including research by NMFS and the Navy's marine mammal
studies, there is no evidence that ``population-level harm'' to marine
mammals is occurring in the MITT Study Area. Through the process
described in the rule and regulations, NMFS will work with the Navy to
assure that the aggregate or cumulative impacts remain at the
negligible impact level.
Regarding the consideration of stress responses, NMFS does not
assume that the impacts are insignificant. There is currently neither
adequate data nor a mechanism by which the impacts of stress from
acoustic exposure can be reliably and independently quantified.
However, stress effects that result from noise exposure likely often
occur concurrently with behavioral disturbance and many are likely
captured and considered in the quantification of other takes by
harassment that occur when individuals come within a certain distance
of a sound source (behavioral disturbance, PTS, and TTS). Further, the
Commenter provides no support for the speculative assertion that
animals that are harassed would have greater susceptibility to vessel
strike, but regardless, the agency's analysis of the likelihood of
vessel strikes considers all available and applicable information (see
the Potential Effects of Vessel Strike subsection of the Potential
Effects of Specified Activities on Marine Mammals and Their Habitat
section of the proposed rule).
NEPA
Comment 58: A Commenter stated that the Navy (and thereby NMFS,
since the agency has adopted the 2020 MITT FSEIS/OEIS to satisfy its
NEPA obligations for the MMPA rulemaking and subsequent issuance of the
Letter of Authorization) failed its NEPA requirements: (1) To inform
the public as to its intentions and the potential impacts of those
intentions in relation to their continued weapons testing in the MITT
Study Area and (2) To consider all available scientific evidence that
their activities are resulting in wider take of marine mammals than
previously known.
Response: NMFS disagrees that the Navy and NMFS failed to satisfy
any NEPA requirements. The Navy prepared, with NMFS participating as a
cooperating agency, and made available for public review and comment
the 2019 MITT DSEIS/OEIS, which fully analyzed the Navy's and NMFS'
proposed actions. To better accommodate stakeholders and the public,
the Navy provided 75 days to review and comment on the 2019 MITT DSEIS/
OEIS. The comment period for the DSEIS/OEIS was from February 1, 2019
to April 17, 2019, which is 30 days longer than the minimum required
time for review (40 CFR 6.203(c)(3)(v)).
The Navy held four open house public meetings, one each on Tinian
(March 14, 2019), Rota (March 15, 2019), Saipan (March 18, 2019), and
Guam (March 19, 2019). The public meetings were an ideal opportunity
for the public to ask questions of Navy team members (and specific
subject matter experts on Saipan and Guam) about the analysis
documented in the 2020 MITT FSEIS/OEIS. The Navy encouraged the
[[Page 46340]]
public to attend these meetings and broadly notified the public through
the media, including paid newspaper advertisements and news releases,
and direct mail, including letters, postcards, and emails.
Further, the 2020 MITT FSEIS/OEIS includes the best available
information regarding the impacts of the Navy's activities on the human
environment, including marine mammals.
Comment 59: A Commenter says that NMFS cannot rely on the EIS to
fulfill its obligations under NEPA. Without significant revision, the
2019 MITT DSEIS/OEIS cannot meet NMFS' NEPA obligations. The Commenter
urges NMFS to recognize that the alternatives and mitigation set forth
in the 2019 MITT DSEIS/OEIS are inadequate and to supplement the
document accordingly.
Response: Consistent with the regulations published by the Council
on Environmental Quality (CEQ), it is common and sound NEPA practice
for NOAA to participate as a cooperating agency and adopt a lead
agency's NEPA analysis when, after independent review, NOAA determines
the document to be sufficient in accordance with 40 CFR 1506.3.
Specifically here, NOAA is satisfied that the 2020 MITT FEIS/OEIS
adequately addresses the impacts of issuing the MMPA incidental take
authorization and that NOAA's comments and concerns have been
adequately addressed. NMFS' early participation in the NEPA process and
role in shaping and informing analyses using its special expertise
ensured that the analysis in the 2020 MITT FSEIS/OEIS is sufficient for
purposes of NMFS' own NEPA obligations related to its issuance of
incidental take authorization under the MMPA.
Regarding the alternatives and mitigation, NMFS' early involvement
in development of the 2020 MITT FSEIS/OEIS and role in evaluating the
effects of incidental take under the MMPA ensured that the 2020 MITT
FSEIS/OEIS would include adequate analysis of a reasonable range of
alternatives. The 2020 MITT FSEIS/OEIS includes a No Action Alternative
specifically to address what could happen if NMFS did not issue an MMPA
authorization. The other two Alternatives address two action options
that the Navy could potentially pursue while also meeting their
mandated Title 10 training and testing responsibilities. More
importantly, these alternatives fully analyze a comprehensive variety
of mitigation measures. This mitigation analysis supported NMFS'
evaluation of our mitigation options in potentially issuing an MMPA
authorization, which, if the authorization can be issued under the
negligible impact standard, primarily revolves around the appropriate
mitigation to prescribe. This approach to evaluating a reasonable range
of alternatives is consistent with NMFS policy and practice for issuing
MMPA incidental take authorizations. NOAA has independently reviewed
and evaluated the 2020 MITT FSEIS/OEIS, including the range of
alternatives, and determined that the 2020 MITT FSEIS/OEIS fully
satisfies NMFS' NEPA obligations related to its decision to issue the
MMPA final rule and associated LOA, and we have adopted it.
Comment 60: To satisfy NEPA's mandate to take a hard look at
environmental impacts, NMFS and the Navy must incorporate new
information (Simonis et al., 2020) into their analysis of the impacts
of MITT activities on marine mammals. Moreover, the agencies must
evaluate alternatives that prohibit the use of harmful sonar in the
biologically important areas for beaked whales around Saipan and Tinian
identified in Simonis et al. (2020).
Response: NMFS has considered Simonis et al. (2020) in the
development of this final rule and directs the reader to the Stranding
section of the rule, as well as the response to Comment 19, in which we
address the areas around Saipan and Tinian referenced in Simonis et al.
(2020). Likewise the Navy has considered this new information from
Simonis et al. (2020) in the 2020 MITT FSEIS/OEIS.
Other Comments
Comment 61: The Commenter argued that an analysis based on reported
strikes by Navy vessels alone does not account for the additional risk
of undetected under-reported whale strikes. In assessing ship-strike
risk, NMFS and the Navy should include offsets to account for
potentially undetected and unreported collisions.
Response: First, it is important to note that NMFS' assessment of
whether ship strike is likely does not rely wholly on whether or not
there have been reported strikes by the Navy in the past, but also
considers the seasonal occurrence and density of large whales, the
stranding record (which could note strikes by other entities), and the
relative percentage of Navy vessel traffic. Regarding the likelihood of
undetected Navy strikes, under Navy-wide policy Navy ships are mandated
to report any Navy ship strike to marine mammals. To date, there have
been none in the MITT Study Area from Navy ships. While NMFS agrees
that broadly speaking the number of total ship strikes from all sources
may be underestimated due to incomplete information from other sectors
(shipping, etc.), NMFS is confident that any whales struck by Navy
vessels are detected and reported (as has occurred in other Navy study
areas), and therefore relying on the history of Navy vessel strikes is
appropriate and supported. Navy ships have multiple Lookouts, including
on the forward part of the ship that can visually detect a struck whale
(which has occasionally occurred elsewhere), in the unlikely event ship
personnel do not feel the strike. The Navy's strict internal procedures
and mitigation requirements in this and previous rules include
reporting of any vessel strikes of marine mammals, and the Navy's
discipline, extensive training (not only for detecting marine mammals,
but for detecting and reporting any potential navigational
obstruction), and strict chain of command give NMFS a high level of
confidence that all strikes actually get reported. For more discussion
of the specific circumstances that make it less likely that Navy
vessels will strike a marine mammal, see the Potential Effects of
Specified Activities on Marine Mammals and Their Habitat section in the
proposed rule. Accordingly, NMFS is confident that the information used
to support the vessel-strike analysis is accurate and complete, and
there is no need to include offsets to account for potentially
undetected and unreported collisions allegedly associated with the
Navy's training and testing activities.
Separately, there is no evidence that Navy training and testing
activities (including acoustic activities) increase the risk of nearby
non-Navy vessels (or other nearby Navy vessels not involved in the
training or testing activities) striking marine mammals.
Changes From the Proposed Rule to the Final Rule
Between the proposed rule and the final rule, mitigation,
monitoring, reporting, and adaptive management measures have been
added, augmented, and clarified, and the negligible impact analysis for
humpback whales around Saipan has been modified.
Specifically regarding the humpback whale assessment, since
publication of the proposed rule, additional information and analysis
have been used to refine the assessment for the impacts of sonar
training and testing on humpback whales around Saipan, resulting in an
increase in the total take numbers for humpback whales. A subsection
describing this additional analysis and how it changes the take numbers
(Humpback Whales Around
[[Page 46341]]
Saipan) has been added to the Estimated Take of Marine Mammals section
and the total take numbers for humpback whales have been changed in
Table 28 and Table 47.
Regarding the changes to mitigation measures, in the Marpi Reef and
Chalan Kanoa Reef Geographic Mitigation Areas, where there was
previously a limitation on the use of explosives but no limitation on
the use of active sonar, there is now a 20-hr annual cap between
December 1 and April 30 on the use of hull-mounted MF1 mid-frequency
active sonar for these areas (20 hrs total for both areas combined), as
well as a requirement that the Navy report all active sonar use (all
bins, by bin) in these areas between December 1 and April 30. These
changes are discussed in greater detail in the Mitigation Measures
section of this rule.
In addition, the Navy has committed to the following actions, which
will expand the science and inform future adaptive management actions
related to beaked whales, specifically, as well as other species in the
MITT Study Area:
1. Co-funding the Pacific Marine Assessment Program for Protected
Species (PACMAPPS) survey in spring-summer 2021 to help document beaked
whale occurrence, abundance, and distribution in the Mariana Islands.
This effort will include deployments of a towed array as well as
floating passive acoustic buoys.
2. Continuing to fund additional stranding response/necropsy
analyses for the Pacific Islands region.
3. Submitting a proposal through the annual Federally Funded
Research and Development Center (FFRDC) call to fund Center for Naval
Analysis (CNA) to develop a framework to improve the analysis of single
and mass stranding events, including the development of more advanced
statistical methods to better characterize the uncertainty associated
with data parameters.
4. Increasing analysis for any future beaked whale stranding in the
Mariana Islands to include detailed Navy review of available records of
sonar use.
5. Monitoring future beaked whale occurrence within select portions
of the MITT Study Area starting in 2022 (so as to not duplicate efforts
from item number 1 above).
6. Including Cuvier's beaked whales as a priority species for
analysis under a 2020-2023 Navy research-funded program entitled Marine
Species Monitoring for Potential Consequences of Disturbance
(MSM4PCOD).
7. Funding and co-organizing with NMFS an expert panel to provide
recommendations on scientific data gaps and uncertainties for further
protective measure consideration to minimize the impact of Navy
training and testing activities on beaked whales in the Mariana
Islands.
These changes are discussed in greater detail in the Monitoring and
Adaptive Management sections of this rule.
Description of Marine Mammals and Their Habitat in the Area of the
Specified Activities
Marine mammal species that have the potential to occur in the MITT
Study Area are presented in Table 7. The Navy anticipates the take of
individuals of 26 marine mammal species by Level A and Level B
harassment incidental to training and testing activities from the use
of sonar and other transducers, and in-water detonations. There are no
areas of critical habitat designated under the Endangered Species Act
(ESA), National Marine Sanctuaries, or unusual mortality events (UMEs)
for marine mammals in the MITT Study Area. However, there are areas
known to be important for humpback whale breeding and calving which are
described below.
The proposed rule included additional information about the species
in this rule, all of which remains valid and applicable but has not
been reprinted in this final rule, including a subsection entitled
Marine Mammal Hearing that described the importance of sound to marine
mammals and characterized the different groups of marine mammals based
on their hearing sensitivity. Therefore, we refer the reader to our
Federal Register notice of proposed rulemaking (85 FR 5782; January 31,
2020) for more information.
Information on the status, distribution, abundance, population
trends, habitat, and ecology of marine mammals in the MITT Study Area
also may be found in Section 4 of the Navy's rulemaking/LOA
application. NMFS reviewed this information and found it to be accurate
and complete. Additional information on the general biology and ecology
of marine mammals is included in the 2020 MITT FSEIS/OEIS. The marine
mammal populations in the MITT Study Area have not been assigned to
stocks and there are no associated SARs. There is only one species,
humpback whales for which stock information exists for species that
occur in the MITT Study Area. Table 7 incorporates the best available
science, including data from the U.S. Pacific and the Alaska Marine
Mammal Stock Assessments Reports (SARs) (Carretta et al., 2019, Muto et
al., 2019), as well as monitoring data from the Navy's marine mammal
research efforts. NMFS also has reviewed the most recent 2019 draft
SARs (which can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports)
and new scientific literature, and determined that none of these nor
any other new information changes our determination of which species
have the potential to be affected by the Navy's activities or the
pertinent information in this final rulemaking.
Table 7--Marine Mammal Occurrence Within the MITT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Status Occurrence *
Common name Scientific name ----------------------------------------------------------------------------------------------
MMPA ESA Mariana Islands Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale........................ Balaenoptera musculus D..................... E..................... Seasonal.............. Seasonal.
Bryde's whale..................... Balaenoptera edeni... ...................... n/a................... Regular............... Regular.
Fin whale......................... Balaenoptera physalus D..................... E..................... Rare.................. Rare.
Humpback whale.................... Megaptera (\1\)................. E..................... Seasonal.............. Seasonal.
novaeangliae.
Minke whale....................... Balaenoptera ...................... n/a................... Seasonal.............. Seasonal.
acutorostrata.
Omura's whale..................... Balaenoptera omurai.. ...................... n/a................... Rare.................. Rare.
Sei whale......................... Balaenoptera borealis D..................... E..................... Seasonal.............. Seasonal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontocetes:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale......... Mesoplodon ...................... n/a................... Regular............... Regular.
densirostris.
[[Page 46342]]
Common bottlenose dolphin......... Tursiops truncatus... ...................... n/a................... Regular............... Regular.
Cuvier's beaked whale............. Ziphius cavirostris.. ...................... n/a................... Regular............... Regular.
Dwarf sperm whale................. Kogia sima........... ...................... n/a................... Regular............... Regular.
False killer whale................ Pseudorca crassidens. ...................... n/a................... Regular............... Regular.
Fraser's dolphin.................. Lagenodelphis hosei.. ...................... n/a................... Regular............... Regular.
Ginkgo-toothed beaked whale....... Mesoplodon ginkgodens ...................... n/a................... Regular............... Regular.
Killer whale...................... Orcinus orca......... ...................... n/a................... Regular............... Regular.
Longman's beaked whale............ Indopacetus pacificus ...................... n/a................... Regular............... Regular.
Melon-headed whale................ Peponocephala electra ...................... n/a................... Regular............... Regular.
Pantropical spotted dolphin....... Stenella attenuata... ...................... n/a................... Regular............... Regular.
Pygmy killer whale................ Feresa attenuata..... ...................... n/a................... Regular............... Regular.
Pygmy sperm whale................. Kogia breviceps...... ...................... n/a................... Regular............... Regular.
Risso's dolphin................... Grampus griseus...... ...................... n/a................... Regular............... Regular.
Rough-toothed dolphin............. Steno bredanensis.... ...................... n/a................... Regular............... Regular.
Short-finned pilot whale.......... Globicephala ...................... n/a................... Regular............... Regular.
macrorhynchus.
Sperm whale....................... Physeter D..................... E..................... Regular............... Regular.
macrocephalus.
Spinner dolphin................... Stenella longirostris ...................... n/a................... Regular............... Regular.
Striped dolphin................... Stenella coeruleoalba ...................... n/a................... Regular............... Regular.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Humpback whales in the Mariana Islands have not been assigned a stock by NMFS in the Alaska or Pacific Stock Assessment Reports given they are not
recognized in those reports as being present in U.S. territorial waters (Carretta et al., 2017c; Carretta et al., 2018; Caretta et al., 2019; Muto et
al., 2017b; Muto et al., 2018, Muto et al., 2019), but because individuals from the Western North Pacific Distinct Population Segment have been
photographically identified in the MITT Study Area, humpback whales in the Mariana Islands are assumed to be part of the Western North Pacific Stock.
Note: Status MMPA, D = depleted; ESA, E = endangered.
* Species occur in both the Mariana Islands and in the Transit Corridor, both of which are included in the overall MITT Study Area. The transit corridor
is outside the geographic boundaries of the MIRC, but is a route across the high seas for Navy ships transiting between the MIRC and the HRC. Although
not part of a defined range complex, vessels and aircraft would at times conduct basic and routine unit-level activities such as gunnery and sonar
training while in transit in the corridor as long as the training would not interfere with the primary objective of reaching their intended
destination. Ships also conduct sonar maintenance, which includes active sonar transmissions.
Humpback Reproductive Areas
The humpback whales in the MITT Study Area are indirectly addressed
in the Alaska SAR, given that the historic range of humpbacks in the
``Asia wintering area'' includes the Mariana Islands. The observed
presence of humpback whales in the Mariana Islands (Hill et al., 2016a;
Hill et al., 2017a; Hill et al., 2018; Hill et al., 2020a; Klinck et
al., 2016a; Munger et al., 2014; NMFS, 2018; Oleson et al., 2015;
Uyeyama, 2014) is consistent with the MITT Study Area as a plausible
migratory destination for humpback whales from Alaska (Muto et al.,
2017a). It was considered likely that humpback whales in the Mariana
Islands are part of the endangered Western North Pacific (WNP) Distinct
Population Segment (DPS) based on the best available science (Bettridge
et al., 2015; Calambokidis et al., 2008; Calambokidis et al., 2010;
Carretta et al., 2017b; Hill et al., 2017b; Hill et al., 2020a; Muto et
al., 2017a; NMFS, 2016a; NOAA, 2015b; Wade et al., 2016) although the
breeding range of the humpback whale WNP DPS is not fully resolved.
Individual photo-identification data for whales sampled off Saipan
within the Mariana Archipelago in February-March 2015 to 2018, suggest
that these whales belong to the WNP DPS (Hill et al., 2020a).
Specifically, comparisons with existing WNP humpback whale photo-
identification catalogs showed that 11 of 41 (27 percent) whales within
the Mariana Archipelago humpback whale catalog were previously sighted
in Western North Pacific humpback whale breeding areas (Japan and
Philippines) and/or in a Western North Pacific humpback whale feeding
area off Russia (Hill et al., 2020a). Hill et al. (2020a) completed DNA
profiling of 28 biopsy samples that identified 24 individuals (14
females, 10 males) representing seven mitochondrial DNA haplotypes. The
haplotype frequencies from the Mariana Archipelago showed the greatest
identity with the Ogasawara breeding ground and Commander Islands
feeding ground in the Western North Pacific. This study establishes the
Mariana Archipelago as a breeding area for the endangered WNP DPS of
humpback whales (Hill et al., 2020a). No ESA critical habitat has been
proposed for the WNP DPS of humpback whales in the MITT Study Area,
although critical habitat has been proposed in Alaska (84 FR 54534;
October 9, 2019).
Humpback whale breeding and calving have been documented in the
MITT Study Area and particularly in the shallow waters (mostly within
the 200-m isobath) offshore of Saipan at Marpi Reef and Chalan Kanoa
Reef. Based on surveys conducted by NMFS' Pacific Islands Fisheries
Science Center (PIFSC) during the winter months (January to March)
2015-2019, there were 22 encounters with mother/calf pairs with a total
of 14 mother/calf pairs and all calves were considered born within the
current season and one neotate (Hill et al., 2020a). Additionally,
competitive groups were observed in 2017 and 2018 (Hill et al., 2020a).
Surveys and passive acoustic hydrophone recordings in the Mariana
Islands has confirmed the presence of mother-calf pairs, non-calf
whales, and singing males in the MITT Study Area (Fulling et al., 2011;
Hill et al., 2016a; Hill et al., 2018; Munger et al., 2014; Munger et
al., 2015; Norris et al., 2012; Oleson and Hill, 2010a; Oleson et al.,
2015; U.S. Department of the Navy, 2007; Uyeyama et al., 2012). Future
surveys are needed to determine the full extent of the humpback whale
breeding habitat throughout the Mariana Archipelago; however, the
available data confirms the shallow waters surrounding Marpi Reef and
Chalan Kanoa Reef are important to breeding and calving humpback
whales.
Species Not Included in the Analysis
Consistent with the analysis provided in the 2015 MITT FEIS/OEIS
and the
[[Page 46343]]
previous Phase II rulemaking for the MITT Study Area, the species
carried forward for analysis and in the Navy's rulemaking/LOA
application are those likely to be found in the MITT Study Area based
on the most recent sighting, survey, and habitat modeling data
available. The analysis does not include species that may have once
inhabited or transited the area, but have not been sighted in recent
years (e.g., species that no longer occur in the area due to factors
such as 19th-century commercial exploitation). These species include
the North Pacific right whale (Eubalaena japonica), the western
subpopulation of gray whale (Eschrichtius robustus), short-beaked
common dolphin (Delphinus delphis), Indo-Pacific bottlenose dolphin
(Tursiops aduncus), northern elephant seal (Mirounga angustirostris),
and dugong (Dugong dugon). The reasons for not including each of these
species was explained in detail in the proposed rulemaking (85 FR 5782;
January 31, 2020) and NMFS agrees these species are unlikely to occur
in the MITT Study Area.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
We provided a detailed discussion of the potential effects of the
specified activity on marine mammals and their habitat in our Federal
Register notice of proposed rulemaking (85 FR 5782; January 31, 2020).
In the Potential Effects of Specified Activities on Marine Mammals and
Their Habitat section of the proposed rule, NMFS provided a description
of the ways marine mammals may be affected by these activities in the
form of, among other things, serious injury or mortality, physical
trauma, sensory impairment (permanent and temporary threshold shift and
acoustic masking), physiological responses (particularly stress
responses), behavioral disturbance, or habitat effects. All of this
information remains valid and applicable. Therefore, we do not reprint
the information here but refer the reader to that document.
NMFS has also reviewed new relevant information from the scientific
literature since publication of the proposed rule. Summaries of the new
key scientific literature since publication of the proposed rule are
presented below.
Accomando et al. (2020) examined the directional dependence of
hearing thresholds for 2, 10, 20, and 30 kHz in two adult bottlenose
dolphins. They observed that source direction (i.e., the relative angle
between the sound source location and the dolphin) impacted hearing
thresholds for these frequencies. Sounds projected from directly behind
the dolphins resulted in frequency-dependent increases in hearing
thresholds of up to 18.5 dB when compared to sounds projected from in
front of the dolphins. Sounds projected directly above the dolphins
resulted in thresholds that were approximately 8 dB higher than those
obtained when sounds were projected below the dolphins. These findings
suggest that dolphins may receive lower source levels when they are
oriented 180 degrees away from the sound source, and dolphins are less
sensitive to sound projected from above (leading to some spatial
release from masking). Directional or spatial hearing also allows
animals to locate sound sources. This study indicates dolphins can
detect source direction at lower frequencies than previously thought,
allowing them to successfully avoid or approach biologically
significant or anthropogenic sound sources at these frequencies.
Houser et al. (2020) measured cortisol, aldosterone, and
epinephrine levels in the blood samples of 30 bottlenose dolphins
before and after exposure to simulated U.S. Navy mid-frequency sonar
from 115-185 dB re: 1 [mu]Pa. They collected blood samples
approximately one week prior to, immediately following, and
approximately one week after exposures and analyzed for hormones via
radioimmunoassay. Aldosterone levels were below the detection limits in
all samples. While the observed severity of behavioral responses scaled
(increased) with SPL, levels of cortisol and epinephrine did not show
consistent relationships with received SPL. The authors note that it is
still unclear whether intermittent, high-level acoustic stimuli elicit
endocrine responses consistent with a stress response, and that
additional research is needed to determine the relationship between
behavioral responses and physiological responses.
In an effort to compare behavioral responses to continuous active
sonar (CAS) and pulsed (intermittent) active sonar (PAS), Isojunno et
al. (2020) conducted at-sea experiments on 16 sperm whales equipped
with animal-attached sound- and movement-recording tags in Norway. They
examined changes in foraging effort and proxies for foraging success
and cost during sonar and control exposures after accounting for
baseline variation. They observed no reduction in time spent foraging
during exposures to medium-level PAS transmitted at the same peak
amplitude as CAS, however they observed similar reductions in foraging
during CAS and PAS when they were received at similar energy levels
(SELs). The authors note that these results support the hypothesis that
sound energy (SEL) is the main cause of behavioral responses rather
than sound amplitude (SPL), and that exposure context and measurements
of cumulative sound energy are important considerations for future
research and noise impact assessments.
Frankel and Stein (2020) used shoreline theodolite tracking to
examine potential behavioral responses of southbound migrating eastern
gray whales to a high-frequency active sonar system transmitted by a
vessel located off the coast of California. The sonar transducer
deployed from the vessel transmitted 21-25 kHz sweeps for half of each
day (experimental period), and no sound the other half of the day
(control period). In contrast to low-frequency active sonar tests
conducted in the same area (Clark et al., 1999; Tyack and Clark, 1998),
no overt behavioral responses or deflections were observed in field or
visual data. However, statistical analysis of the tracking data
indicated that during experimental periods at received levels of
approximately 148 dB re: 1 [mu]Pa\2\ (134 dB re: 1 [mu]Pa\2\s) and less
than 2 km from the transmitting vessel, gray whales deflected their
migration paths inshore from the vessel. The authors indicate that
these data suggest the functional hearing sensitivity of gray whales
extends to at least 21 kHz. These findings agree with the predicted
mysticete hearing curve and behavioral response functions used in the
analysis to estimate take by Level A harassment (PTS) and Level B
harassment (behavioral response) for this rule (see the Technical
Report ``Criteria and Thresholds for U.S. Navy Acoustic and Explosive
Effects Analysis (Phase III)'').
Having considered the new information, along with information
provided in public comments on the proposed rule, we have determined
that there is no new information that substantively affects our
analysis of potential impacts on marine mammals and their habitat that
appeared in the proposed rule, all of which remains applicable and
valid for our assessment of the effects of the Navy's activities during
the seven-year period of this rule.
Vessel Strike
NMFS also considered the chance that a vessel utilized in training
or testing activities could strike a marine mammal. Vessel strikes have
the potential to result in incidental take from serious injury and/or
mortality. Vessel strikes are not specific to any particular training
or testing activity,
[[Page 46344]]
but rather are a limited, sporadic, and incidental result of Navy
vessel movement within a study area. NMFS' detailed analysis of the
likelihood of vessel strike was provided in the Potential Effects of
Vessel Strike section of our Federal Register notice of proposed
rulemaking (85 FR 5782; January 31, 2020); please see that notice of
proposed rulemaking or the Navy's application for more information. No
additional information has been received since publication of the
proposed rule that substantively changes the agency's analysis or
conclusions. Therefore the information and analysis included in the
proposed rule supports NMFS' concurrence with the Navy's conclusion and
our final determination that vessel strikes of marine mammals, and
associated serious injury or mortality, are not likely to result from
the Navy's activities included in this seven-year rule, and vessel
strikes are not discussed further.
Stranding
In the proposed rule, NMFS discussed the potential mechanisms that
could lead from acoustic exposure to marine mammal strandings and
described the small number of global events in which strandings
(predominantly of beaked whales) have been causally associated with
exposure to active sonar in certain circumstances. Given the available
information, NMFS did not anticipate or propose to authorize mortality
of beaked whales resulting from the Navy activities covered under the
rule. Public commenters questioned this preliminary determination and
additional information has become available since the proposed rule was
published. Therefore an updated and expanded rationale, in addition to
what was included in the proposed rule, describing why NMFS continues
to conclude that mortality is not reasonably likely to result from
these activities following careful and thorough review of all available
information is included here.
In February 2020, a study (Simonis et al., 2020) was published
titled ``Co-occurrence of beaked whale strandings and naval sonar in
the Mariana Islands, Western Pacific.'' In summary, the authors
compiled the publicly available information regarding Navy training
exercises from 2006-2019 (from press releases, etc.), as well as the
passive acoustic monitoring data indicating sonar use that they
collected at two specific locations on HARP recorders over a shorter
amount of time, and compared it to the dates of beaked whale
strandings. Using this data, they reported that six of the 10 Cuvier's
beaked whales, from four of eight events, stranded during or within six
days of a naval ASW exercise using sonar. In a Note to the article, the
authors acknowledged additional information provided by the Navy while
the article was in press that one of the strandings occurred a day
prior to sonar transmissions and so should not be considered coincident
with sonar. The authors' analysis examined the probability that the now
three of eight random days would fall during, or within six days after,
a naval event (utilizing the Navy training events and sonar detections
of which the authors were aware). Their test results indicated that the
probability that three of eight stranding events were randomly
associated with naval sonar was one percent.
The authors did not have access to the Navy's classified data (in
the Note added to the article, Simonis et al. noted that the Navy was
working with NMFS to make the broader classified dataset available for
further statistical analysis). Later reporting by the Navy indicated
there were more than three times as many sonar days in the Marianas
during the designated time period than Simonis et al. (2020) reported.
Primarily for this reason, the Navy tasked the Center for Naval
Analysis (CNA) with repeating the statistical examination of Simonis et
al. using the full classified sonar record, including ship movement
information to document the precise times and locations of Navy sonar
use throughout the time period of consideration (2007-2019).
CNA re-evaluated the relationship between the strandings and sonar
activities using the entire classified data set in two ways. First,
from their sonar database, CNA tabulated the number of ``sonar days''
for use in their analysis. The total number of sonar days from the
classified database was 923 days (or approximately 19.5 percent of all
days in the study timeframe). In comparison, the Simonis et al. (2020)
analysis assumed only 293 days of sonar (or approximately 6.1 percent
of all days in the study timeframe). CNA conducted re-constructions for
each stranding event to determine/confirm if Navy sonar use coincided
in time and space with each stranding location. The Navy extended the
analysis through the entire year of 2019 to capture both sonar use and
stranding events. As a result, the CNA analysis included consideration
of the November 2019 stranding of a single beaked whale on Rota, which
was not addressed in the Simonis et al. (2020) paper.
A distance of 80 nmi is used in NMFS' incidental take regulations
to evaluate strandings in the context of major training events (MTE),
although of note none of the Marianas stranding events occurred during
an MTE. All strandings reported to have been coincident with sonar use
in Simonis et al., as well as the additional stranding that occurred
while Simonis et al. was in press, were confirmed to be coincident by
the CNA analysis (i.e., within 80 nmi) and, for the first analysis, CNA
examined the four strandings in relation to the total sonar days
(throughout the MITT Study Area) recorded in the classified data set.
Based on the calculations conducted by CNA, when the analysis is
conducted consistent with the Simonis et al. (2020) assumptions (i.e.,
without considering proximity of sonar to strandings in counting
``sonar days''), but with consideration of the accurate number of sonar
days from the classified record and the additional stranding at Rota,
the analysis suggests that the probability that four of nine stranding
events were randomly associated with naval events is 10 percent, which
the Navy interpreted as insufficient evidence, at P<0.10 threshold
level, to claim a relationship between sonar use and stranding in the
Mariana Islands.
For the second CNA analysis, the same four coincident strandings
were considered, but only sonar use within a maximum distance of 80 nmi
from a stranding location would be considered as possibly influencing a
potential stranding event and, therefore, included in the ``sonar
days'' for this analysis. This analysis resulted in the calculations
being performed separately for Guam, Rota, and Saipan.
When the analysis was conducted specifically for Guam including
only those sonar days within 80 nmi, the results suggested that the
probability that the strandings are randomly associated with sonar was
notably higher, at 26 percent (p=0.26). This is notable because this
location had the highest number of overall stranding events (n=7),
coincident stranding events (n=2), and sonar days (n=681) of all the
locations within the Mariana Islands. The calculations for Saipan and
Rota (p=0.06 and 0.14, respectively) should be viewed with caution
given that statistical analyses considering single data points (i.e.,
one stranding each) have low power and high uncertainty and, similarly,
the Navy reported insufficient evidence to claim a relationship (at
P<0. 05 and 0.10 levels, respectively) between sonar use and
strandings. NMFS has evaluated the Navy's analysis and results along
with the analysis and results of Simonis et al. (2020), and has
determined that both
[[Page 46345]]
analyses are appropriate to consider in NMFS' assessment of whether
beaked whale mortality is reasonably likely to occur as a result of the
Navy's activities described in this seven-year rule.
Standard statistical significance thresholds of 0.05 and 0.1 are
often used in the interpretation of the results of statistical tests,
and the Navy stated that their results show that the data showing the
relationship between sonar and stranding is not statistically
significant, and does not allow one to rule out a null hypothesis that
there is no relationship. NMFS consulted guidance from the American
Statistical Association, which cautions against strict interpretations
of p-values and notes that ``researchers should bring many contextual
factors into play to derive scientific inferences, including the design
of a study, the quality of the measurements, the external evidence for
the phenomenon under study, and the validity of assumptions that
underlie the data analysis. Pragmatic considerations often require
binary, ``yes-no'' decisions, but this does not mean that p-values
alone can ensure that a decision is correct or incorrect.'' Separately,
we also note that the Navy strove to use identical methods as the
Simonis et al. (2020) paper to conduct their analysis. A
miscommunication resulted in the Navy initially using a Poisson
distribution, while Simonis et al. used a permutation test, however,
additional tests were run to ensure an apples-to-apples comparison. The
tests were consistent and the results are reflected in the discussion
above. Last, and importantly, we note that correlation does not equate
to causation.
In addition to examining the correlation (or lack thereof) of
activities with strandings, necropsies of stranded animals can provide
insight into the potential cause of death. The number of strandings
that can be thoroughly investigated through necropsy, sample
collection, and advanced diagnostics is limited to animals that are not
returned to the sea and those that are found and accessible prior to
extensive decomposition. In the case of beaked whale strandings that
occurred in the MITT Study Area during this time period, necropsy
examinations were performed and high quality tissue samples were
collected from three live stranded or fresh dead individuals: one of
the whales from the August 2011 Saipan stranding, the single whale from
the March 2015 Guam stranding, and the single whale from the January
2019 Guam stranding. For the stranding events for which necropsies and
histopathology analyses were conducted, only the 2011 and 2015 events
were coincident with the use of Navy sonar.
None of the three beaked whales from the Mariana Islands had
evidence of gas bubble formation in the organs examined grossly and
histologically. Stranding response staff from the University of Hawaii
conducted the examinations and compared the results to the diagnostic
features of gas and fat embolic syndrome described by Bernaldo de
Quiros et al. (2019). Bernaldo de Quiros et al. (2019) established that
to date, strandings which have a confirmed association with naval
exercise have exhibited all seven of the following diagnostic features:
1. Individual or multiple animals stranded within hours or a few
days of an exercise in good body condition;
2. Food remnants in the first gastric compartment ranging from
undigested food to squid beaks;
3. Abundant gas bubbles widely distributed in veins (subcutaneous,
mesenteric, portal, coronary, subarachnoid veins, etc.) composed
primarily of N2 in fresh carcasses;
4. Gross subarachnoid and/or acoustic fat hemorrhages;
5. Microscopic multi-organ gas and fat emboli associated with
bronchopulmonary shock;
6. Diffuse, mild to moderate, acute, monophasic myonecrosis
(hyaline degeneration) with ``disintegration'' of the interstitial
connective tissue and related structures, including fat deposits, and
their replacement by amorphous hyaline material (degraded material) in
fresh and well preserved carcasses; and
7. Multi-organ microscopic hemorrhages of varying severity in
lipid-rich tissues such as the central nervous system, spinal cord, and
the coronary and kidney fat when present.
Results from the necropsies for the 2011 and 2015 stranded animals
indicate that they only exhibited one to three of the diagnostic
features, but not all seven. Additionally, the necropsy results from
both animals indicated severe parasite infestations. The 2015 specimen
also had indication of myocardial fibrosis which could have impacted
cardiac function. Results for the 2019 animal, which was a stranding
that was not coincident with sonar, indicated that it exhibited up to
3\1\ of the 7 diagnostic features. Overall, the results of these
necropsies appear to align with evidence from single beaked whale
strandings in the Canary Islands between 2002 and 2015 (n=45) which
stranded with no known correlation in space or time with active sonar.
These individuals had one or more diagnostic features of gas and fat
embolic syndrome for beaked whales stranded in association with MFAS
exercises, but not all seven (Bernaldo de Quiros et al. 2019). NMFS
acknowledges that situations could potentially occur in which beaked
whales might strand as a result of sonar exposure and not exhibit all
seven of the features of gas and fat embolic syndrome described above,
however, taken as a whole, these necropsy and histopathology results do
not support a conclusion that the 2011 and 2015 strandings resulted
from exposure to naval sonar. Furthermore, the role of natural
stressors or other non-Navy factors as they affect beaked whale
strandings is not understood. The majority of strandings in the MITT
Study Area occurred without the presence of Navy sonar.
---------------------------------------------------------------------------
\1\ One of the diagnostic features is ``individual or multiple
animals stranded within hours or a few days of an exercise in good
body condition,'' however, Bernaldo de Quiros et al. (2019) does not
specify if the stranding had to occur after an exercise in which
sonar use occurred. One would presume it does since it investigated
sonar's ability to cause strandings. The 2019 animal stranded close
in time to the outset of a Navy training event, however, sonar use
did not occur until the day after the stranding. Therefore, this
event is not considered coincident, but due to the ambiguity in the
description of this diagnostic factor, the 2019 stranding is
conservatively assumed to be positive for this factor.
---------------------------------------------------------------------------
As noted previously, NMFS has acknowledged that it is possible for
naval activities using hull-mounted tactical sonar to contribute to the
death of marine mammals in certain circumstances via strandings
resulting from behaviorally mediated physiological impacts or other
gas-related injuries. In the proposed rule, NMFS discussed these
potential causes and outlined the few cases where active naval sonar
(in the United States or, largely, elsewhere) had either potentially
contributed to or (as with the Bahamas example) been more definitively
causally linked with marine mammal mass strandings (more than two
animals). There have been no documented mass strandings of beaked
whales in the Marianas since stranding data was collected, and the
first beaked whale stranding was documented in 2007, while the Navy has
been using sonar in the Marianas since the 1960s. As also noted
previously, there are a suite of factors that have been associated with
the specific cases of strandings directly causally associated with
sonar (steep bathymetry, multiple hull-mounted platforms using sonar
simultaneously, constricted channels, strong surface ducts, etc.) that
are not present together in the MITT Study Area
[[Page 46346]]
and during the specified activities (and which the Navy takes care
across the world not to operate under without additional monitoring).
Further none of the documented strandings in the MITT Study Area have
coincided with MTEs.
While the results of the Simonis et al. (2020) paper and the fuller
CNA analysis both suggest (the latter to a notably lesser degree) that
it is more probable than not that there was some form of non-random
relationship between sonar days and strandings in the Marianas during
this period of time, the results of the Navy analysis (using the full
dataset) allow, statistically, that the strandings and sonar use may
not be related. Given the uncertainties and assumptions inherent in
these correlation analyses, the small sample size (in terms of the
strandings), and the fact that correlation does not equate to
causation--these results, alone, do not indicate a reasonable
likelihood that the Navy's activities under this rule will result in
serious injury or mortality of beaked whales. Further, the necropsies
of the two animals stranded in the MITT Study Area in 2011 and 2015 do
not support a conclusion that the 2011 and 2015 strandings resulted
from exposure to naval sonar. When this information is considered in
combination with the absence of mass beaked whale strandings in the
MITT Study Area and the absence of beaked whale strandings coinciding
with any MTEs, despite Navy sonar training activity in the area since
the 1960s, NMFS has concluded that serious injury or mortality of
beaked whales is unlikely to result from the Navy activities covered
under this seven-year rule.
While we have found that serious injury or mortality are not likely
to result from the activities covered by this rule, we note the number
of beaked whale strandings in the MITT Study Area (acknowledging the
comparatively lower carcass recovery rate for offshore species), the
paucity of beaked whale data in the region, and the Simonis et al. and
Navy analysis results, all of which highlight the need for additional
data-gathering and future analysis. Accordingly, as part of the
monitoring and adaptive management requirements of the final rule (as
described elsewhere), in addition to continuing to fund stranding
investigations in the Marianas and other monitoring measures, the Navy
will fund and co-organize with NMFS an expert panel to provide
recommendations addressing scientific data gaps and uncertainties to
further inform consideration of future protective measures to minimize
the impact of Navy training and testing activities on beaked whales in
the Mariana Islands.
Estimated Take of Marine Mammals
This section indicates the number of takes that NMFS is
authorizing, which are based on the maximum amount of take that NMFS
anticipates is likely to occur. NMFS coordinated closely with the Navy
in the development of their incidental take application, and agrees
that the methods the Navy put forth to estimate take (including the
model, thresholds, and density estimates), and the resulting numbers
are based on the best available science and appropriate for
authorization. Nonetheless, since publication of the proposed rule,
additional information and analysis have been used to refine the
assessment for the impacts of sonar training and testing on humpback
whales around Saipan, resulting in a change in the total take numbers
for humpback whales. A subsection describing this additional analysis
and how it changes the take numbers (Humpback Whales Around Saipan) is
included below and the total take numbers for humpback whales has
increased in Table 28 and 47.
Takes are in the form of harassment only. For military readiness
activities, the MMPA defines ``harassment'' as (i) Any act that injures
or has the significant potential to injure a marine mammal or marine
mammal stock in the wild (Level A harassment); or (ii) Any act that
disturbs or is likely to disturb a marine mammal or marine mammal stock
in the wild by causing disruption of natural behavioral patterns,
including, but not limited to, migration, surfacing, nursing, breeding,
feeding, or sheltering, to a point where such behavioral patterns are
abandoned or significantly altered (Level B harassment).
Authorized takes will primarily be in the form of Level B
harassment, as use of the acoustic and explosive sources (i.e., sonar
and explosives) is more likely to result in behavioral disruption
(rising to the level of a take as described above) or temporary
threshold shift (TTS) for marine mammals than other forms of take.
There is also the potential for Level A harassment, however, in the
form of auditory injury and/or tissue damage (the latter from
explosives only) to result from exposure to the sound sources utilized
in training and testing activities.
Generally speaking, for acoustic impacts NMFS estimates the amount
and type of harassment by considering: (1) Acoustic thresholds above
which NMFS believes the best available science indicates marine mammals
will be taken by Level B harassment (in this case, as defined in the
military readiness definition of Level B harassment included above) or
incur some degree of temporary or permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day or event; (3) the density or occurrence of marine mammals within
these ensonified areas; and (4) the number of days of activities or
events. Below, we describe these components in more detail and present
the take estimates.
Acoustic Thresholds
Using the best available science, NMFS, in coordination with the
Navy, has established acoustic thresholds that identify the most
appropriate received level of underwater sound above which marine
mammals exposed to these sound sources could be reasonably expected to
experience a disruption in behavior patterns to a point where they are
abandoned or significantly altered, or to incur TTS (equated to Level B
harassment) or PTS of some degree (equated to Level A harassment).
Thresholds have also been developed to identify the pressure levels
above which animals may incur non-auditory injury from exposure to
pressure waves from explosive detonation.
Despite the quickly evolving science, there are still challenges in
quantifying expected behavioral responses that qualify as take by Level
B harassment, especially where the goal is to use one or two
predictable indicators (e.g., received level and distance) to predict
responses that are also driven by additional factors that cannot be
easily incorporated into the thresholds (e.g., context). So, while the
behavioral harassment thresholds have been refined here to better
consider the best available science (e.g., incorporating both received
level and distance), they also still have some built-in conservative
factors to address the challenge noted. For example, while duration of
observed responses in the data are now considered in the thresholds,
some of the responses that are informing take thresholds are of a very
short duration, such that it is possible some of these responses might
not always rise to the level of disrupting behavior patterns to a point
where they are abandoned or significantly altered. We describe the
application of this behavioral harassment threshold as identifying the
maximum number of instances in which marine mammals could be reasonably
expected to experience a disruption in behavior patterns to a point
where they are abandoned or significantly altered. In summary, we
believe these behavioral
[[Page 46347]]
harassment thresholds are the most appropriate method for predicting
Level B harassment by behavioral disturbance given the best available
science and the associated uncertainty.
Hearing Impairment (TTS/PTS), Tissues Damage, and Mortality
NMFS' Acoustic Technical Guidance (NMFS, 2018) identifies dual
criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). The Acoustic Technical Guidance also
identifies criteria to predict TTS, which is not considered injury and
falls into the Level B harassment category. The Navy's planned activity
includes the use of non-impulsive (sonar) and impulsive (explosives)
sources. These thresholds (Tables 8 and 9) were developed by compiling
and synthesizing the best available science and soliciting input
multiple times from both the public and peer reviewers. The references,
analysis, and methodology used in the development of the thresholds are
described in Acoustic Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 8--Acoustic Thresholds Identifying the Onset of TTS and PTS for
Non-Impulsive Sound Sources by Functional Hearing Groups
------------------------------------------------------------------------
Non-impulsive
-------------------------------
Functional hearing group TTS Threshold PTS threshold
SEL (weighted) SEL (weighted)
------------------------------------------------------------------------
Low-Frequency Cetaceans................. 179 199
Mid-Frequency Cetaceans................. 178 198
High-Frequency Cetaceans................ 153 173
------------------------------------------------------------------------
Note: SEL thresholds in dB re 1 [mu]Pa\2\s.
Based on the best available science, the Navy (in coordination with
NMFS) used the acoustic and pressure thresholds indicated in Table 9 to
predict the onset of TTS, PTS, tissue damage, and mortality for
explosives (impulsive) and other impulsive sound sources.
Table 9--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mean onset slight Mean onset slight Mean onset
Functional hearing group Species Onset TTS Onset PTS GI tract injury lung injury mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans......... All mysticetes.... 168 dB SEL 183 dB SEL 237 dB Peak SPL... Equation 1........ Equation 2.
(weighted) or 213 (weighted). or
dB Peak SPL. 219 dB Peak SPL.
Mid-frequency cetaceans......... Most delphinids, 170 dB SEL 185 dB SEL 237 dB Peak SPL...
medium and large (weighted) or 224 (weighted) or 230
toothed whales. dB Peak SPL. dB Peak SPL.
High-frequency cetaceans........ Porpoises and 140 dB SEL 155 dB SEL 237 dB Peak SPL...
Kogia spp.. (weighted) or 196 (weighted) or 202
dB Peak SPL. dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
Equation 1: 47.5M\1/3\ (1+[D\Rm\/10.1])\1/6\ Pa-sec.
Equation 2: 103M\1/3\ (1+[D\Rm\/10.1])\1/6\ Pa-sec.
M = mass of the animals in kg.
D\Rm\ = depth of the receiver (animal) in meters.
SPL = sound pressure level.
The criteria used to assess the onset of TTS and PTS due to
exposure to sonars (non-impulsive, see Table 8 above) are discussed
further in the Navy's rulemaking/LOA application (see Hearing Loss from
Sonar and Other Transducers in Section 6, Section 6.4.2.1, Methods for
Analyzing Impacts from Sonars and Other Transducers). Refer to the
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects
Analysis (Phase III) report (U.S. Department of the Navy, 2017c) for
detailed information on how the criteria and thresholds were derived.
Non-auditory injury (i.e., other than PTS) and mortality from sonar and
other transducers is so unlikely as to be discountable under normal
conditions for the reasons explained in the proposed rule under the
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat section--Acoustically Mediated Bubble Growth and other
Pressure-related Injury, and is therefore not considered further in
this analysis. As noted previously, additional information and analysis
has been added to the Potential Effects of Specified Activities on
Marine Mammals and Their Habitat section of this final rule
specifically addressing and ruling out the likelihood of mortality of
beaked whales through strandings associated with sonar exposure.
The mitigation measures associated with explosives are expected to
be effective in preventing tissue damage to
[[Page 46348]]
any potentially affected species, and when considered in combination
with the modeled exposure results, no species are anticipated to incur
tissue damage during the period of this rule. Tables 26 indicate the
range to effects for tissue damage for different explosive types. The
Navy will implement mitigation measures (described in the Mitigation
Measures section) during explosive activities, including delaying
detonations when a marine mammal is observed in the mitigation zone.
Nearly all explosive events will occur during daylight hours to improve
the sightability of marine mammals and thereby improve mitigation
effectiveness. Observing for marine mammals during the explosive
activities will include visual and passive acoustic detection methods
(when they are available and part of the activity) before the activity
begins, in order to cover the mitigation zones that can range from 200
yds (183 m) to 2,500 yds (2,286 m) depending on the source (e.g.,
explosive sonobuoy, explosive torpedo, explosive bombs), and 2.5 nmi
for sinking exercise (see Tables 34-39).
Level B Harassment by Behavioral Disturbance
Though significantly driven by received level, the onset of Level B
harassment by behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source (e.g., frequency, predictability, duty cycle), the environment
(e.g., bathymetry), and the receiving animals (hearing, motivation,
experience, demography, behavioral context) and can be difficult to
predict (Ellison et al., 2011; Southall et al., 2007). Based on what
the available science indicates and the practical need to use
thresholds based on a factor, or factors, that are both predictable and
measurable for most activities, NMFS uses generalized acoustic
thresholds based primarily on received level (and distance in some
cases) to estimate the onset of Level B harassment by behavioral
disturbance.
Sonar--As noted above, the Navy coordinated with NMFS to develop,
and propose for use in this rule, behavioral harassment thresholds
specific to their military readiness activities utilizing active sonar.
These behavioral harassment thresholds consist of behavioral response
functions (BRFs) and associated cutoff distances, and are also referred
to, together, as ``the criteria.'' These criteria are used to estimate
the number of animals that may exhibit a behavioral response that rises
to the level of a take when exposed to sonar and other transducers. The
way the criteria were derived is discussed in detail in the Criteria
and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis
(Phase III) report (U.S. Department of the Navy, 2017c). Developing
these behavioral harassment thresholds involved multiple steps. All
peer-reviewed published behavioral response studies conducted both in
the field and on captive animals were examined in order to understand
the breadth of behavioral responses of marine mammals to sonar and
other transducers. NMFS has carefully reviewed the Navy's criteria,
i.e., BRFs and cutoff distances for the species, and agrees that they
are the best available science and the appropriate method to use at
this time for determining impacts to marine mammals from sonar and
other transducers and for calculating take and to support the
determinations made in this rule. The Navy and NMFS will continue to
evaluate the information as new science becomes available. The criteria
have been rigorously vetted within the Navy community, among scientists
during expert elicitation, and then reviewed by the public before being
applied. It is not necessary or possible to revise and update the
criteria and risk functions every time a new paper is published. The
Navy is considering new information as it becomes available for updates
to the criteria in the future, when the next round of updated criteria
will be developed. Thus far, no new information has been published or
otherwise conveyed that would fundamentally change the assessment of
impacts or conclusions of the 2020 MITT FSEIS/OEIS or this rule.
As discussed above, marine mammal responses to sound (some of which
are considered disturbances that rise to the level of a take) are
highly variable and context specific, i.e., they are affected by
differences in acoustic conditions; differences between species and
populations; differences in gender, age, reproductive status, or social
behavior; or other prior experience of the individuals. This means that
there is support for considering alternative approaches for estimating
Level B harassment by behavioral disturbance. Although the statutory
definition of Level B harassment for military readiness activities
states that a natural behavior pattern of a marine mammal is
significantly altered or abandoned, the current state of science for
determining those thresholds is somewhat unsettled.
In its analysis of impacts associated with sonar acoustic sources
(which was coordinated with NMFS), the Navy used an updated
conservative approach that likely overestimates the number of takes by
Level B harassment due to behavioral disturbance and response. Many of
the behavioral responses identified using the Navy's quantitative
analysis are most likely to be of moderate severity as described in the
Southall et al. (2007) behavioral response severity scale. These
``moderate'' severity responses were considered significant if they
were sustained for the duration of the exposure or longer. Within the
Navy's quantitative analysis, many reactions are predicted from
exposure to sound that may exceed an animal's threshold for Level B
harassment by behavioral disturbance for only a single exposure (a few
seconds) to several minutes, and it is likely that some of the
resulting estimated behavioral responses that are counted as Level B
harassment would not constitute significant alteration or abandonment
of the natural behavioral patterns. The Navy and NMFS have used the
best available science to address the challenging differentiation
between significant and non-significant behavioral reactions (i.e.,
whether the behavior has been abandoned or significantly altered such
that it qualifies as harassment), but have erred on the cautious side
where uncertainty exists (e.g., counting these lower duration reactions
as take), which likely results in some degree of overestimation of
Level B harassment by behavioral disturbance. We consider application
of these behavioral harassment thresholds, therefore, as identifying
the maximum number of instances in which marine mammals could be
reasonably expected to experience a disruption in behavior patterns to
a point where they are abandoned or significantly altered (i.e., Level
B harassment). Because this is the most appropriate method for
estimating Level B harassment given the best available science and
uncertainty on the topic, it is these numbers of Level B harassment by
behavioral disturbance that are analyzed in the Analysis and Negligible
Impact Determination section and are authorized.
In the Navy's acoustic impact analyses during Phase II (the
previous phase of Navy testing and training, 2015-2020; see also Navy's
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects
Analysis Technical Report, 2012), the likelihood of Level B harassment
by behavioral disturbance in response to sonar and other transducers
was based on a probabilistic function (BRF) that related the likelihood
(i.e., probability) of a behavioral response (at the level of a Level B
harassment) to the received SPL. The BRF was used to estimate the
percentage of an exposed population that is likely to exhibit Level
[[Page 46349]]
B harassment due to altered behaviors or behavioral disturbance at a
given received SPL. This BRF relied on the assumption that sound poses
a negligible risk to marine mammals if they are exposed to SPL below a
certain ``basement'' value. Above the basement exposure SPL, the
probability of a response increased with increasing SPL. Two BRFs were
used in Navy acoustic impact analyses: BRF1 for mysticetes and BRF2 for
other species. BRFs were not used for beaked whales during Phase II
analyses. Instead, a step function at an SPL of 140 dB re 1 [mu]Pa was
used for beaked whales as the threshold to predict Level B harassment
by behavioral disturbance.
Developing the criteria for Level B harassment by behavioral
disturbance for Phase III (the current phase of Navy training and
testing activities) involved multiple steps: all available behavioral
response studies conducted both in the field and on captive animals
were examined to understand the breadth of behavioral responses of
marine mammals to sonar and other transducers (see also Navy's Criteria
and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis
(Phase III) Technical Report, 2017). Six behavioral response field
studies with observations of 14 different marine mammal species
reactions to sonar or sonar-like signals and 6 captive animal
behavioral studies with observations of 8 different species reactions
to sonar or sonar-like signals were used to provide a robust data set
for the derivation of the Navy's Phase III marine mammal behavioral
response criteria. All behavioral response research that has been
published since the derivation of the Navy's Phase III criteria (c.a.
December 2016) has been examined and is consistent with the current
behavioral response functions. Marine mammal species were placed into
behavioral criteria groups based on their known or suspected behavioral
sensitivities to sound. In most cases these divisions were driven by
taxonomic classifications (e.g., mysticetes, pinnipeds). The data from
the behavioral studies were analyzed by looking for significant
responses, or lack thereof, for each experimental session. The
resulting four Bayesian Biphasic Dose Response Functions (referred to
as the BRFs) that were developed for odontocetes, pinnipeds,
mysticetes, and beaked whales predict the probability of a behavioral
response qualifying as Level B harassment given exposure to certain
received levels of sound. These BRFs are then used in combination with
the cutoff distances described below to estimate the number of takes by
Level B harassment.
The Navy used cutoff distances beyond which the potential of
significant behavioral responses (and therefore Level B harassment) is
considered to be unlikely (see Table 10 below). This was determined by
examining all available published field observations of behavioral
reactions to sonar or sonar-like signals that included the distance
between the sound source and the marine mammal. The longest distance,
rounded up to the nearest 5-km increment, was chosen as the cutoff
distance for each behavioral criteria group (i.e., odontocetes,
mysticetes, and beaked whales). For animals within the cutoff distance,
a behavioral response function based on a received SPL as presented in
Section 3, Section 3.1.0 of the Navy's rulemaking/LOA application was
used to predict the probability of a potential significant behavioral
response. For training and testing events that contain multiple
platforms or tactical sonar sources that exceed 215 dB re 1 [micro]Pa
@1 m, this cutoff distance is substantially increased (i.e., doubled)
from values derived from the literature. The use of multiple platforms
and intense sound sources (high source level) are factors that probably
increase responsiveness in marine mammals overall (however, we note
that helicopter dipping sonars were considered in the intense sound
source group, despite lower source levels, because of data indicating
that marine mammals are sometimes more responsive to the less
predictable employment of this source). There are currently few
behavioral observations under these circumstances; therefore, the Navy
conservatively predicted significant behavioral responses that will
rise to Level B harassment at farther ranges as shown in Table 10,
versus less intense events.
Table 10--Cutoff Distances for Moderate Source Level, Single Platform
Training and Testing Events and for all Other Events With Multiple
Platforms or Sonar With Source Levels at or Exceeding 215 dB re 1
[micro]Pa @1 m
------------------------------------------------------------------------
Moderate SL/
single High SL/ multi-
Criteria group platform platform
cutoff cutoff
distance (km) distance (km)
------------------------------------------------------------------------
Odontocetes............................. 10 20
Mysticetes.............................. 10 20
Beaked Whales........................... 25 50
------------------------------------------------------------------------
Note: dB re 1 [micro]Pa @1 m = decibels referenced to 1 micropascal at 1
meter; km = kilometer; SL = source level.
The range to received sound levels in 6-dB steps from five
representative sonar bins and the percentage of animals that may be
taken by Level B harassment at the received level and distance
indicated under each behavioral response function are shown in Table 11
through Table 15. Cells are shaded if the mean range value for the
specified received level exceeds the distance cutoff range for a
particular hearing group and therefore are not included in the
estimated take. See Section 6, Section 6.4.2.1.1 (Methods for Analyzing
Impacts from Sonars and Other Transducers) of the Navy's rulemaking/LOA
application for further details on the derivation and use of the
behavioral response functions, thresholds, and the cutoff distances to
identify takes by Level B harassment, which were coordinated with NMFS.
Table 11 illustrates the maximum likely percentage of exposed
individuals taken at the indicated received level and associated range
(in which marine mammals would be reasonably expected to experience a
disruption in behavior patterns to a point where they are abandoned or
significantly altered) for LFAS. As noted previously, NMFS carefully
reviewed, and contributed to, the Navy's behavioral harassment
thresholds (i.e., the BRFs and the cutoff distances) for the species,
and agrees that these methods represent the best available science at
this time for determining impacts to marine mammals from sonar and
other transducers.
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Tables 12 through 15 identify the maximum likely percentage of
exposed individuals taken at the indicated received level and
associated range for MFAS.
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Table 15--Ranges to Estimated Level B Harassment by Behavioral Disturbance for Sonar Bin HF4 Over a
Representative Range of Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Probability of level B harassment by
Average range (m) with behavioral disturbance for sonar bin HF4
Received level (dB re 1 [mu]Pa) minimum and maximum values in -----------------------------------------------
parenthesis Odontocetes Mysticetes
(percent) (percent) Beaked whales
----------------------------------------------------------------------------------------------------------------
196.............................. 3 (2-4)...................... 100 100 100
190.............................. 8 (6-10)..................... 100 98 100
184.............................. 16 (12-20)................... 99 88 100
178.............................. 32 (24-40)................... 97 59 100
172.............................. 63 (45-80)................... 91 30 99
166.............................. 120 (75-160)................. 78 20 97
160.............................. 225 (120-310)................ 58 18 93
154.............................. 392 (180-550)................ 40 17 83
148.............................. 642 (280-1,275).............. 29 16 66
142.............................. 916 (420-1,775).............. 25 13 45
136.............................. 1,359 (625-2,525)............ 23 9 28
130.............................. 1,821 (950-3,275)............ 20 5 18
124.............................. 2,567 (1,275-5,025).......... 17 2 14
118.............................. 3,457 (1,775-6,025).......... 12 1 12
112.............................. 4,269 (2,275-7,025).......... 6 0 11
106.............................. 5,300 (3,025-8,025).......... 3 0 11
100.............................. 6,254 (3,775-9,275).......... 1 0 8
----------------------------------------------------------------------------------------------------------------
Notes: dB re 1 [mu]Pa = decibels referenced to 1 micropascal, m = meters.
Explosives--Phase III explosive thresholds for Level B harassment
by behavioral disturbance for marine mammals is the hearing groups' TTS
threshold minus 5 dB (see Table 16 below and Table 9 for the TTS
thresholds for explosives) for events that contain multiple impulses
from explosives underwater. This was the same approach as taken in
Phase II for explosive analysis. See the Criteria and Thresholds for
U.S. Navy Acoustic and Explosive Effects Analysis (Phase III) report
(U.S. Department of the Navy, 2017c) for detailed information on how
the criteria and thresholds were derived. NMFS continues to concur that
this approach represents the best available science for determining
impacts to marine mammals from explosives.
Table 16--Thresholds for Level B Harassment by Behavioral Disturbance
for Explosives for Marine Mammals
------------------------------------------------------------------------
Functional hearing
Medium group SEL (weighted)
------------------------------------------------------------------------
Underwater...................... LF 163
Underwater...................... MF 165
Underwater...................... HF 135
------------------------------------------------------------------------
Note: Weighted SEL thresholds in dB re 1 [mu]Pa\2\s underwater.
[[Page 46358]]
Navy's Acoustic Effects Model
The Navy's Acoustic Effects Model calculates sound energy
propagation from sonar and other transducers and explosives during
naval activities and the sound received by animat dosimeters. Animat
dosimeters are virtual representations of marine mammals distributed in
the area around the modeled naval activity and each dosimeter records
its individual sound ``dose.'' The model bases the distribution of
animats over the MITT Study Area on the density values in the Navy
Marine Species Density Database and distributes animats in the water
column proportional to the known time that species spend at varying
depths.
The model accounts for environmental variability of sound
propagation in both distance and depth when computing the received
sound level received by the animats. The model conducts a statistical
analysis based on multiple model runs to compute the estimated effects
on animals. The number of animats that exceed the thresholds for
effects is tallied to provide an estimate of the number of marine
mammals that could be affected.
Assumptions in the Navy model intentionally err on the side of
overestimation when there are unknowns. Naval activities are modeled as
though they would occur regardless of proximity to marine mammals,
meaning that no mitigation is considered (i.e., no power down or shut
down modeled) and without any avoidance of the activity by the animal.
The final step of the quantitative analysis of acoustic effects is to
consider the implementation of mitigation and the possibility that
marine mammals would avoid continued or repeated sound exposures. For
more information on this process, see the discussion in the Take
Estimation subsection below. Many explosions from ordnance such as
bombs and missiles actually occur upon impact with above-water targets.
However, for this analysis, sources such as these were modeled as
exploding underwater, which overestimates the amount of explosive and
acoustic energy entering the water.
The model estimates the impacts caused by individual training and
testing exercises. During any individual modeled event, impacts to
individual animats are considered over 24-hour periods. The animats do
not represent actual animals, but rather they represent a distribution
of animals based on density and abundance data, which allows for a
statistical analysis of the number of instances that marine mammals may
be exposed to sound levels resulting in an effect. Therefore, the model
estimates the number of instances in which an effect threshold was
exceeded over the course of a year, but does not estimate the number of
individual marine mammals that may be impacted over a year (i.e., some
marine mammals could be impacted several times, while others would not
experience any impact). A detailed explanation of the Navy's Acoustic
Effects Model is provided in the technical report Quantifying Acoustic
Impacts on Marine Mammals and Sea Turtles: Methods and Analytical
Approach for Phase III Training and Testing report (U.S. Department of
the Navy, 2018).
Range to Effects
The following section provides range to effects for sonar and other
active acoustic sources, as well as explosives, to specific acoustic
thresholds determined using the Navy Acoustic Effects Model. Marine
mammals exposed within these ranges for the shown duration are
predicted to experience the associated effect. Range to effects is
important information in not only predicting acoustic impacts, but also
in verifying the accuracy of model results against real-world
situations and determining adequate mitigation ranges to avoid higher
level effects, especially physiological effects to marine mammals.
Sonar
The range to received sound levels in 6-dB steps from five
representative sonar bins and the percentage of the total number of
animals that may exhibit a significant behavioral response (and
therefore Level B harassment) under each behavioral response function
are shown in Table 11 through Table 15 above, respectively. See Section
6, Section 6.4.2.1 (Methods for Analyzing Impacts from Sonars and Other
Transducers) of the Navy's rulemaking/LOA application for additional
details on the derivation and use of the behavioral response functions,
thresholds, and the cutoff distances that are used to identify Level B
harassment by behavioral disturbance. NMFS has reviewed the range
distance to effect data provided by the Navy and concurs with the
analysis.
The ranges to PTS for five representative sonar systems for an
exposure of 30 seconds is shown in Table 17 relative to the marine
mammal's functional hearing group. This period (30 seconds) was chosen
based on examining the maximum amount of time a marine mammal would
realistically be exposed to levels that could cause the onset of PTS
based on platform (e.g., ship) speed and a nominal animal swim speed of
approximately 1.5 m per second. The ranges provided in the table
include the average range to PTS, as well as the range from the minimum
to the maximum distance at which PTS is possible for each hearing
group.
Table 17--Range to Permanent Threshold Shift (Meters) for Five Representative Sonar Systems
----------------------------------------------------------------------------------------------------------------
Approximate range in meters for PTS from 30 second exposure \1\
Hearing group -------------------------------------------------------------------------------
Sonar bin HF4 Sonar bin LF4 Sonar bin MF1 Sonar bin MF4 Sonar bin MF5
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........ 29 (22-35) 0 (0-0) 181 (180-190) 30 (30-30) 9 (8-10)
Low-frequency cetaceans......... 0 (0-0) 0 (0-0) 65 (65-65) 15 (15-15) 0 (0-0)
Mid-frequency cetaceans......... 1 (0-1) 0 (0-0) 16 (16-16) 3 (3-3) 0 (0-0)
----------------------------------------------------------------------------------------------------------------
\1\ PTS ranges extend from the sonar or other active acoustic sound source to the indicated distance. The
average range to PTS is provided as well as the range from the estimated minimum to the maximum range to PTS
in parenthesis.
The tables below illustrate the range to TTS for 1, 30, 60, and 120
seconds from five representative sonar systems (see Table 18 through
Table 22).
[[Page 46359]]
Table 18--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin LF4 Over a Representative Range of
Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
---------------------------------------------------------------
Hearing group Sonar bin LF4
---------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........................ 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0)
Low-frequency cetaceans......................... 3 (3-3) 4 (4-4) 6 (6-6) 9 (9-9)
Mid-frequency cetaceans......................... 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
in parentheses.
Table 19--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin MF1 Over a Representative Range of
Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
-----------------------------------------------------------------------------------
Hearing group Sonar Bin MF1
-----------------------------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans.... 3,181 (2,025-5,025) 3,181 (2,025-5,025) 5,298 (2,275-7,775) 6,436 (2,525-9,775)
Low-frequency cetaceans..... 898 (850-1,025) 898 (850-1,025) 1,271 (1,025-1,525) 1,867 (1,275-3,025)
Mid-frequency cetaceans..... 210 (200-210) 210 (200-210) 302 (300-310) 377 (370-390)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
in parentheses.
Note: Ranges for 1-second and 30-second periods are identical for Bin MF1 because this system nominally pings
every 50 seconds; therefore, these periods encompass only a single ping.
Table 20--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin MF4 Over a Representative Range of
Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
-----------------------------------------------------------------
Hearing group Sonar bin MF4
-----------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans...................... 232 (220-260) 454 (420-600) 601 (575-875) 878 (800-1,525)
Low-frequency cetaceans....................... 85 (85-90) 161 (160-170) 229 (220-250) 352 (330-410)
Mid-frequency cetaceans....................... 22 (22-22) 35 (35-35) 50 (45-50) 70 (70-70)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
in parentheses.
Table 21--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin MF5 Over a Representative Range of
Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
---------------------------------------------------------------
Hearing group Sonar bin MF5
---------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........................ 114 (110-130) 114 (110-130) 168 (150-200) 249 (210-290)
Low-frequency cetaceans......................... 11 (10-12) 11 (10-12) 16 (16-17) 23 (23-24)
Mid-frequency cetaceans......................... 5 (0-9) 5 (0-9) 12 (11-13) 18 (17-18)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
in parentheses.
[[Page 46360]]
Table 22--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin HF4 Over a Representative Range of
Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
---------------------------------------------------------------
Hearing group Sonar bin HF4
---------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........................ 155 (110-210) 259 (180-350) 344 (240-480) 445 (300-600)
Low-frequency cetaceans......................... 1 (0-2) 2 (1-3) 4 (3-5) 7 (5-8)
Mid-frequency cetaceans......................... 10 (7-12) 17 (12-21) 24 (17-30) 33 (25-40)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
in parentheses.
Explosives
The following section provides the range (distance) over which
specific physiological or behavioral effects are expected to occur
based on the explosive criteria (see Section 6, Section 6.5.2.1.1 of
the Navy's rulemaking/LOA application and the Criteria and Thresholds
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)
report (U.S. Department of the Navy, 2017c)) and the explosive
propagation calculations from the Navy Acoustic Effects Model (see
Section 6, Section 6.5.2.1.3, Navy Acoustic Effects Model of the Navy's
rulemaking/LOA application). The range to effects are shown for a range
of explosive bins, from E1 (up to 0.25 lb net explosive weight) to E12
(up to 1,000 lb net explosive weight) (Tables 23 through 27). Ranges
are determined by modeling the distance that noise from an explosion
would need to propagate to reach exposure level thresholds specific to
a hearing group that would cause behavioral response (to the degree of
Level B harassment), TTS, PTS, and non-auditory injury. Ranges are
provided for a representative source depth and cluster size for each
bin. For events with multiple explosions, sound from successive
explosions can be expected to accumulate and increase the range to the
onset of an impact based on SEL thresholds. Ranges to non-auditory
injury and mortality are shown in Tables 26 and 27, respectively. NMFS
has reviewed the range distance to effect data provided by the Navy and
concurs with the analysis. For additional information on how ranges to
impacts from explosions were estimated, see the technical report
Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods
and Analytical Approach for Phase III Training and Testing (U.S. Navy,
2018).
Table 23 shows the minimum, average, and maximum ranges to onset of
auditory and likely behavioral effects that rise to the level of Level
B harassment for high-frequency cetaceans based on the developed
thresholds.
Table 23--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance for High-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives bin: high-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source Depth
Bin (m) Cluster Size PTS TTS Behavioral disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................... 0.1 1 353 (340-370) 1,303 (1,275-1,775) 2,139 (2,025-4,275)
.............. 18 1,031 (1,025-1,275) 3,409 (2,525-8,025) 4,208 (3,025-11,525)
E2........................................... 0.1 1 431 (410-700) 1,691 (1,525-2,775) 2,550 (2,025-4,525)
.............. 5 819 (775-1,275) 2,896 (2,275-6,775) 3,627 (2,525-10,275)
E3........................................... 0.1 1 649 (625-700) 2,439 (2,025-4,525) 3,329 (2,525-7,525)
.............. 12 1,682 (1,525-2,275) 4,196 (3,025-11,525) 5,388 (4,525-16,275)
18.25 1 720 (675-775) 4,214 (2,275-6,275) 7,126 (3,525-8,775)
.............. 12 1,798 (1,525-2,775) 10,872 (4,525-13,775) 14,553 (5,525-17,775)
E4........................................... 10 2 1,365 (1,025-2,775) 7,097 (4,275-10,025) 9,939 (5,025-15,275)
60 2 1,056 (875-2,275) 3,746 (2,775-5,775) 5,262 (3,025-7,775)
E5........................................... 0.1 20 2,926 (1,525-6,275) 6,741 (4,525-16,025) 9,161 (4,775-20,025)
30 20 4,199 (3,025-6,275) 13,783 (8,775-17,775) 17,360 (10,525-22,775)
E6........................................... 0.1 1 1,031 (1,025-1,275) 3,693 (2,025-8,025) 4,659 (3,025-12,775)
30 1 1,268 (1,025-1,275) 7,277 (3,775-8,775) 10,688 (5,275-12,525)
E8........................................... 0.1 1 1,790 (1,775-3,025) 4,581 (4,025-10,775) 6,028 (4,525-15,775)
45.75 1 1,842 (1,525-2,025) 9,040 (4,525-12,775) 12,729 (5,025-18,525)
E9........................................... 0.1 1 2,343 (2,275-4,525) 5,212 (4,025-13,275) 7,573 (5,025-17,025)
E10.......................................... 0.1 1 2,758 (2,275-5,025) 6,209 (4,275-16,525) 8,578 (5,275-19,775)
E11.......................................... 45.75 1 3,005 (2,525-3,775) 11,648 (5,025-18,775) 14,912 (6,525-24,775)
91.4 1 3,234 (2,525-4,525) 5,772 (4,775-11,775) 7,197 (5,775-14,025)
E12.......................................... 0.1 1 3,172 (3,025-6,525) 7,058 (5,025-17,025) 9,262 (6,025-21,775)
.............. 4 4,209 (3,775-10,025) 9,817 (6,275-22,025) 12,432 (7,525-27,775)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral disturbance thresholds are depicted above the minimum and maximum distances which are in
parentheses. Values depict the range produced by SEL hearing threshold criteria levels.
Table 24 shows the minimum, average, and maximum ranges to onset of
auditory and likely behavioral effects that rise to the level of Level
B harassment for mid-frequency cetaceans based on the developed
thresholds.
[[Page 46361]]
Table 24--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance for Mid-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives bin: mid-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source depth
Bin (m) Cluster size PTS TTS Behavioral disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................... 0.1 1 25 (25-25) 116 (110-120) 199 (190-210)
18 94 (90-100) 415 (390-440) 646 (525-700)
E2........................................... 0.1 1 30 (30-35) 146 (140-170) 248 (230-370)
5 63 (60-70) 301 (280-410) 481 (430-675)
E3........................................... 0.1 1 50 (50-50) 233 (220-250) 381 (360-400)
12 155 (150-160) 642 (525-700) 977 (700-1,025)
18.25 1 40 (40-40) 202 (190-220) 332 (320-350)
12 126 (120-130) 729 (675-775) 1,025 (1,025-1,025)
E4........................................... 10 2 76 (70-90) 464 (410-550) 783 (650-975)
60 2 60 (60-60) 347 (310-675) 575 (525-900)
E5........................................... 0.1 20 290 (280-300) 1,001 (750-1,275) 1,613 (925-3,275)
30 20 297 (240-420) 1,608 (1,275-2,775) 2,307 (2,025-2,775)
E6........................................... 0.1 1 98 (95-100) 430 (400-450) 669 (550-725)
30 1 78 (75-80) 389 (370-410) 619 (600-650)
E8........................................... 0.1 1 162 (150-170) 665 (550-700) 982 (725-1,025)
45.75 1 127 (120-130) 611 (600-625) 985 (950-1,025)
E9........................................... 0.1 1 215 (210-220) 866 (625-1,000) 1,218 (800-1,525)
E10.......................................... 0.1 1 270 (250-280) 985 (700-1,275) 1,506 (875-2,525)
E11.......................................... 45.75 1 241 (230-250) 1,059 (1,000-1,275) 1,874 (1,525-2,025)
91.4 1 237 (230-270) 1,123 (900-2,025) 1,731 (1,275-2,775)
E12.......................................... 0.1 1 332 (320-370) 1,196 (825-1,525) 1,766 (1,025-3,525)
4 572 (500-600) 1,932 (1,025-4,025) 2,708 (1,275-6,775)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral disturbance thresholds are depicted above the minimum and maximum distances which are in
parentheses. Values depict the range produced by SEL hearing threshold criteria levels.
Table 25 shows the minimum, average, and maximum ranges to onset of
auditory and likely behavioral effects that rise to the level of Level
B harassment for low-frequency cetaceans based on the developed
thresholds.
Table 25--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance for Low-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives bin: low-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source depth
Bin (m) Cluster size PTS TTS Behavioral disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................... 0.1 1 51 (50-55) 231 (200-250) 378 (280-410)
18 183 (170-190) 691 (450-775) 934 (575-1,275)
E2........................................... 0.1 1 66 (65-70) 291 (220-320) 463 (330-500)
5 134 (110-140) 543 (370-600) 769 (490-950)
E3........................................... 0.1 1 113 (110-120) 477 (330-525) 689 (440-825)
12 327 (250-370) 952 (600-1,525) 1,240 (775-4,025)
18.25 1 200 (200-200) 955 (925-1,000) 1,534 (1,275-1,775)
12 625 (600-625) 5,517 (2,275-7,775) 10,299 (3,775-13,025)
E4........................................... 10 2 429 (370-600) 2,108 (1,775-2,775) 4,663 (3,025-6,025)
60 2 367 (340-470) 1,595 (1,025-2,025) 2,468 (1,525-4,275)
E5........................................... 0.1 20 702 (380-1,275) 1,667 (850-11,025) 2,998 (1,025-19,775)
30 20 1,794 (1,275-2,775) 8,341 (3,775-11,525) 13,946 (4,025-22,275)
E6........................................... 0.1 1 250 (190-410) 882 (480-1,775) 1,089 (625-6,525)
30 1 495 (490-500) 2,315 (2,025-2,525) 5,446 (3,275-6,025)
E8........................................... 0.1 1 415 (270-725) 1,193 (625-4,275) 1,818 (825-8,525)
45.75 1 952 (900-975) 6,294 (3,025-9,525) 12,263 (4,275-20,025)
E9........................................... 0.1 1 573 (320-1,025) 1,516 (725-7,275) 2,411 (950-14,275)
E10.......................................... 0.1 1 715 (370-1,525) 2,088 (825-28,275) 4,378 (1,025-32,275)
E11.......................................... 45.75 1 1,881 (1,525-2,275) 12,425 (4,275-27,275) 23,054 (7,025-65,275)
91.4 1 1,634 (1,275-2,525) 5,686 (3,775-11,275) 11,618 (5,525-64,275)
E12.......................................... 0.1 1 790 (420-2,775) 2,698 (925-25,275) 6,032 (1,025-31,275)
4 1,196 (575-6,025) 6,876 (1,525-31,275) 13,073 (3,775-64,275)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral disturbance thresholds are depicted above the minimum and maximum distances which are in
parentheses. Values depict the range produced by SEL hearing threshold criteria levels.
Table 26 shows the minimum, average, and maximum ranges due to
varying propagation conditions to non-auditory injury as a function of
animal mass and explosive bin (i.e., net explosive weight). Ranges to
gastrointestinal tract injury typically exceed ranges to slight lung
injury; therefore, the maximum range to effect
[[Page 46362]]
is not mass-dependent. Animals within these water volumes would be
expected to receive minor injuries at the outer ranges, increasing to
more substantial injuries, and finally mortality as an animal
approaches the detonation point.
Table 26--Ranges \1\ to 50 Percent Non-Auditory Injury Risk for All
Marine Mammal Hearing Groups
------------------------------------------------------------------------
Range (m) (min-
Bin max)
------------------------------------------------------------------------
1....................................................... 12 (11-13)
E2...................................................... 16 (15-16)
E3...................................................... 25 (25-25)
E4...................................................... 30 (30-35)
E5...................................................... 40 (40-65)
E6...................................................... 52 (50-60)
E8...................................................... 98 (90-150)
E9...................................................... 123 (120-270)
E10..................................................... 155 (150-430)
E11..................................................... 418 (410-420)
E12..................................................... 195 (180-675)
------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum
and maximum distances due to varying propagation environments in
parentheses.
Note: All ranges to non-auditory injury within this table are driven by
gastrointestinal tract injury thresholds regardless of animal mass.
Ranges to mortality, based on animal mass, are shown in Table 27
below.
Table 27--Ranges \1\ to 50 Percent Mortality Risk for All Marine Mammal Hearing Groups as a Function of Animal Mass
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to mortality (meters) for various animal mass intervals (kg) \1\
Bin -----------------------------------------------------------------------------------------------
10 250 1,000 5,000 25,000 72,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1...................................................... 3 (3-3) 1 (0-2) 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0)
E2...................................................... 4 (3-4) 2 (1-3) 1 (0-1) 0 (0-0) 0 (0-0) 0 (0-0)
E3...................................................... 9 (7-10) 4 (2-8) 2 (1-2) 1 (0-1) 0 (0-0) 0 (0-0)
E4...................................................... 13 (12-15) 7 (4-12) 3 (3-4) 2 (1-3) 1 (1-1) 1 (0-1)
E5...................................................... 13 (12-30) 7 (4-25) 3 (2-7) 2 (1-5) 1 (1-2) 1 (0-2)
E6...................................................... 16 (15-25) 9 (5-23) 4 (3-8) 3 (2-6) 1 (1-2) 1 (1-2)
E8...................................................... 42 (25-65) 22 (9-50) 11 (6-19) 8 (4-13) 4 (2-6) 3 (1-5)
E9...................................................... 33 (30-35) 20 (13-30) 10 (9-12) 7 (5-9) 4 (3-4) 3 (2-3)
E10..................................................... 55 (40-170) 24 (16-35) 13 (11-15) 9 (7-11) 5 (4-5) 4 (3-4)
E11..................................................... 206 (200-210) 98 (55-170) 44 (35-50) 30 (25-35) 16 (14-18) 12 (10-15)
E12..................................................... 86 (50-270) 35 (20-210) 16 (13-19) 11 (9-13) 6 (5-6) 5 (4-5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to mortality is depicted above the minimum and maximum distances, which are in parentheses.
Marine Mammal Density
A quantitative analysis of impacts on a species or stock requires
data on their abundance and distribution that may be affected by
anthropogenic activities in the potentially impacted area. The most
appropriate metric for this type of analysis is density, which is the
number of animals present per unit area. Marine species density
estimation requires a significant amount of effort to both collect and
analyze data to produce a reasonable estimate. Unlike surveys for
terrestrial wildlife, many marine species spend much of their time
submerged, and are not easily observed. In order to collect enough
sighting data to make reasonable density estimates, multiple
observations are required, often in areas that are not easily
accessible (e.g., far offshore). Ideally, marine mammal species
sighting data would be collected for the specific area and time period
(e.g., season) of interest and density estimates derived accordingly.
However, in many places, poor weather conditions and high sea states
prohibit the completion of comprehensive visual surveys.
For most cetacean species, abundance is estimated using line-
transect surveys or mark-recapture studies (e.g., Barlow, 2010; Barlow
and Forney, 2007; Calambokidis et al., 2008). The result provides one
single density estimate value for each species across broad geographic
areas. This is the general approach applied in estimating cetacean
abundance in NMFS' SARs. Although the single value provides a good
average estimate of abundance (total number of individuals) for a
specified area, it does not provide information on the species
distribution or concentrations within that area, and it does not
estimate density for other timeframes or seasons that were not
surveyed. More recently, spatial habitat modeling developed by NMFS'
Southwest Fisheries Science Center has been used to estimate cetacean
densities (Barlow et al., 2009; Becker et al., 2010, 2012a, b, c, 2014,
2016; Ferguson et al., 2006a; Forney et al., 2012, 2015; Redfern et
al., 2006). These models estimate cetacean density as a continuous
function of habitat variables (e.g., sea surface temperature, seafloor
depth, etc.) and thus allow predictions of cetacean densities on finer
spatial scales than traditional line-transect or mark recapture
analyses and for areas that have not been surveyed. Within the
geographic area that was modeled, densities can be predicted wherever
these habitat variables can be measured or estimated.
Ideally, density data would be available for all species throughout
the study area year-round, in order to best estimate the impacts of
Navy activities on marine species. However, in many places, ship
availability, lack of funding, inclement weather conditions, and high
sea states prevent the completion of comprehensive year-round surveys.
Even with surveys that are completed, poor conditions may result in
lower sighting rates for species that would typically be sighted with
greater frequency under favorable conditions. Lower sighting rates
preclude having an acceptably low uncertainty in the density estimates.
A high level of uncertainty, indicating a low level of confidence in
the density estimate, is typical for species that are rare or difficult
to sight. In areas where survey data are limited or non-existent, known
or inferred associations between marine
[[Page 46363]]
habitat features and the likely presence of specific species are
sometimes used to predict densities in the absence of actual animal
sightings. Consequently, there is no single source of density data for
every area, species, and season because of the fiscal costs, resources,
and effort involved in providing enough survey coverage to consistently
estimate density.
To characterize marine species density for large oceanic regions,
the Navy reviews, critically assesses, and prioritizes existing density
estimates from multiple sources, requiring the development of a
systematic method for selecting the most appropriate density estimate
for each combination of species, area, and season. The selection and
compilation of the best available marine species density data resulted
in the Navy Marine Species Density Database (NMSDD). The Navy vetted
all cetacean densities with NMFS prior to use in the Navy's acoustic
analysis for this MITT rulemaking.
A variety of density data and density models are needed in order to
develop a density database that encompasses the entirety of the MITT
Study Area. Because this data is collected using different methods with
varying amounts of accuracy and uncertainty, the Navy has developed a
hierarchy to ensure the most accurate data is used when available. The
technical report titled U.S. Navy Marine Species Density Database Phase
III for the Mariana Islands Training and Testing Study Area (U.S.
Department of the Navy, 2018), hereafter referred to as the Density
Technical Report, describes these models in detail and provides
detailed explanations of the models applied to each species density
estimate. The list below describes models in order of preference.
1. Spatial density models are preferred and used when available
because they provide an estimate with the least amount of uncertainty
by deriving estimates for divided segments of the sampling area. These
models (see Becker et al., 2016; Forney et al., 2015) predict spatial
variability of animal presence as a function of habitat variables
(e.g., sea surface temperature, seafloor depth, etc.). This model is
developed for areas, species, and, when available, specific timeframes
(months or seasons) with sufficient survey data; therefore, this model
cannot be used for species with low numbers of sightings.
2. Stratified design-based density estimates use line-transect
survey data with the sampling area divided (stratified) into sub-
regions, and a density is predicted for each sub-region (see Barlow,
2016; Becker et al., 2016; Bradford et al., 2017; Campbell et al.,
2014; Jefferson et al., 2014). While geographically stratified density
estimates provide a better indication of a species' distribution within
the study area, the uncertainty is typically high because each sub-
region estimate is based on a smaller stratified segment of the overall
survey effort.
3. Design-based density estimations use line-transect survey data
from land and aerial surveys designed to cover a specific geographic
area (see Carretta et al., 2015). These estimates use the same survey
data as stratified design-based estimates, but are not segmented into
sub-regions and instead provide one estimate for a large surveyed area.
Although relative environmental suitability (RES) models provide
estimates for areas of the oceans that have not been surveyed using
information on species occurrence and inferred habitat associations and
have been used in past density databases, these models were not used in
the current quantitative analysis.
Below we describe how densities were determined for the species in
the MITT Study Area. In the MITT Study Area there is a paucity of line-
transect survey data, and little is known about the stock structure of
the majority of marine mammal species in the region. The only habitat
model available for the MITT Study Area was developed for sperm whales
based on acoustic data collected during a 2007 line-transect survey
(Yack et al., 2016). For other species, the Navy conducted the first
comprehensive marine mammal survey of waters off Guam and the
Commonwealth of the Northern Mariana Islands in 2007, and data from
this survey were used to derive line-transect abundance estimates for
12 cetacean species (Fulling et al., 2011). There has not been a
subsequent systematic survey of the MITT Study Area at this scale, so
these data still provide the best available density estimates for this
region for these species.
In the absence of study-area-specific density data, line-transect
estimates derived for Hawaiian waters were used to provide conservative
density estimates for the remaining species in the MITT Study Area. For
Phase II, these estimates were based on systematic surveys conducted by
NMFS' Southwest Fisheries Science Center (SWFSC) within the EEZ of the
Hawaiian Islands (2010) and Palmyra Atoll/Kingman Reef (2011-2012)
allowed NMFS' PIFSC to update the line-transect density estimates that
included new sea-state-specific estimates of trackline detection
probability (Bradford et al., 2017) and represent improvements to the
estimates used for Phase II. In addition, an updated density estimate
for minke whale was available for Phase III based on line-transect
analyses of acoustic data collected from a towed hydrophone during the
2007 systematic survey (Norris et al., 2017).
The Navy developed a protocol and database to select the best
available data sources based on species, area, and time (season). The
resulting Geographic Information System database, used in the NMSDD,
includes seasonal density values for every marine mammal species
present within the MITT Study Area. This database is described in the
Density Technical Report.
The Navy describes some of the challenges of interpreting the
results of the quantitative analysis summarized above and described in
the Density Technical Report: ``It is important to consider that even
the best estimate of marine species density is really a model
representation of the values of concentration where these animals might
occur. Each model is limited to the variables and assumptions
considered by the original data source provider. No mathematical model
representation of any biological population is perfect, and with
regards to marine mammal biodiversity, any single model method will not
completely explain the actual distribution and abundance of marine
mammal species. It is expected that there would be anomalies in the
results that need to be evaluated, with independent information for
each case, to support if we might accept or reject a model or portions
of the model (U.S. Department of the Navy, 2017a).''
NMFS coordinated with the Navy in the development of its take
estimates and concurs that the Navy's approach for density
appropriately utilizes the best available science. Later, in the
Analysis and Negligible Impact Determination section, we assess how the
estimated take numbers compare to abundance in order to better
understand the potential number of individuals impacted.
Take Estimation
The 2020 MITT FSEIS/OEIS considered all training and testing
activities planned to occur in the MITT Study Area that have the
potential to result in the MMPA-defined take of marine mammals. The
Navy determined that the two stressors below could result in the
incidental taking of marine mammals. NMFS has reviewed the Navy's data
and analysis and determined that it is complete and accurate and agrees
that the following
[[Page 46364]]
stressors have the potential to result in takes by harassment of marine
mammals from the Navy's planned activities.
[ssquf] Acoustics (sonar and other transducers);
[ssquf] Explosives (explosive shock wave and sound, assumed to
encompass the risk due to fragmentation).
The quantitative analysis process used for the 2020 MITT FSEIS/OEIS
and the Navy's take request in the rulemaking/LOA application to
estimate potential exposures to marine mammals resulting from acoustic
and explosive stressors is detailed in the technical report titled
Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods
and Analytical Approach for Phase III Training and Testing (U.S.
Department of the Navy, 2018). The Navy Acoustic Effects Model (NAEMO)
brings together scenario simulations of the Navy's activities, sound
propagation modeling, and marine mammal distribution (based on density
and group size) by species to model and quantify the exposure of marine
mammals above identified thresholds for behavioral harassment, TTS,
PTS, non-auditory injury, and mortality.
NAEMO estimates acoustic and explosive effects without taking
mitigation into account; therefore, the model overestimates predicted
impacts on marine mammals within mitigation zones. To account for
mitigation for marine species in the take estimates, the Navy conducts
a quantitative assessment of mitigation. The Navy conservatively
quantifies the manner in which procedural mitigation is expected to
reduce the risk for model-estimated PTS for exposures to sonars and for
model-estimated mortality for exposures to explosives, based on species
sightability, observation area, visibility, and the ability to exercise
positive control over the sound source. See the proposed rule (85 FR
5782; January 31, 2020) for a description of the process for assessing
the effectiveness of procedural mitigation measures, along with the
process for assessing the potential for animal avoidance. Where the
analysis indicates mitigation would effectively reduce risk, the model-
estimated PTS takes are considered reduced to TTS and the model-
estimated mortalities are considered reduced to injury. For a complete
explanation of the process for assessing the effects of procedural
mitigation, see the Navy's rulemaking/LOA application (Section 6: Take
Estimates for Marine Mammals, and Section 11: Mitigation Measures) and
the technical report titled Quantifying Acoustic Impacts on Marine
Mammals and Sea Turtles: Methods and Analytical Approach for Phase III
Training and Testing (U.S. Department of the Navy, 2018). The extent to
which the mitigation areas reduce impacts on the affected species is
addressed qualitatively separately in the Analysis and Negligible
Impact Determination section.
NMFS coordinated with the Navy in the development of this
quantitative method to address the effects of procedural mitigation on
acoustic and explosive exposures and takes, and NMFS independently
reviewed and concurs with the Navy that it is appropriate to
incorporate the quantitative assessment of mitigation into the take
estimates based on the best available science.
As a general matter, NMFS does not prescribe the methods for
estimating take for any applicant, but we review and ensure that
applicants use the best available science, and methodologies that are
logical and technically sound. Applicants may use different methods of
calculating take (especially when using models) and still get to a
result that is representative of the best available science and that
allows for a rigorous and accurate evaluation of the effects on the
affected populations. There are multiple pieces of the Navy take
estimation methods--propagation models, animat movement models, and
behavioral thresholds, for example. NMFS evaluates the acceptability of
these pieces as they evolve and are used in different rules and impact
analyses. Some of the pieces of the Navy's take estimation process have
been used in Navy incidental take rules since 2009 and undergone
multiple public comment processes, all of them have undergone extensive
internal Navy review, and all of them have undergone comprehensive
review by NMFS, which has sometimes resulted in modifications to
methods or models.
The Navy uses rigorous review processes (verification, validation,
and accreditation processes, peer and public review) to ensure the data
and methodology it uses represent the best available science. For
instance, the NAEMO model is the result of a NMFS-led Center for
Independent Experts (CIE) review of the components used in earlier
models. The acoustic propagation component of the NAEMO model (CASS/
GRAB) is accredited by the Oceanographic and Atmospheric Master Library
(OAML), and many of the environmental variables used in the NAEMO model
come from approved OAML databases and are based on in-situ data
collection. The animal density components of the NAEMO model are base
products of the NMSDD, which includes animal density components that
have been validated and reviewed by a variety of scientists from NMFS
Science Centers and academic institutions. Several components of the
model, for example the Duke University habitat-based density models,
have been published in peer reviewed literature. Others like the
Atlantic Marine Assessment Program for Protected Species, which was
conducted by NMFS Science Centers, have undergone quality assurance and
quality control (QA/QC) processes. Finally the NAEMO model simulation
components underwent QA/QC review and validation for model parts such
as the scenario builder, acoustic builder, scenario simulator, etc.,
conducted by qualified statisticians and modelers to ensure accuracy.
Other models and methodologies have gone through similar review
processes.
In summary, we believe the Navy's methods, including the underlying
NAEMO modeling and the method for incorporating mitigation and
avoidance, are the most appropriate methods for predicting non-auditory
injury, PTS, TTS, and behavioral disturbance. But even with the
consideration of mitigation and avoidance, given some of the more
conservative components of the methodology (e.g., the thresholds do not
consider ear recovery between pulses), we would describe the
application of these methods as identifying the maximum number of
instances in which marine mammals would be reasonably expected to be
taken through non-auditory injury, PTS, TTS, or behavioral disturbance.
Humpback Whales Around Saipan
As noted above, since publication of the proposed rule, additional
information and analysis have been used to refine the assessment for
the impacts of sonar training and testing on humpback whales around
Saipan, resulting in an increase in the total take numbers for humpback
whales. Below, we present updated information describing both the
Navy's activities and expected humpback whale occurrence in the
specific area, as well as the additional analysis of this information
to estimate take of humpback whales in this subset of the MITT Study
Area. This information was then used to refine the total take numbers
for humpback whales and the change is reflected in Table 28 and Table
47.
Given concern for impacts to humpback whales, including cow-calf
pairs, in the Chalan Kanoa Reef and Marpi Reef Geographic Mitigation
Areas, more specific information regarding Navy activities, and the
[[Page 46365]]
availability of more detailed occurrence data for humpback whales in
these areas, and in coordination with NMFS' Interagency Cooperation
Division, NMFS has updated and refined the analysis of humpback whale
impacts in these areas since publication of the proposed rule. The
analysis considers the new annual 20-hour cap on MF1 hull-mounted sonar
in both mitigation areas and, specifically, estimates potential take of
humpback whales should the Navy conduct the full 20 hours of sonar
training and testing in these areas, most likely in the form of a Small
Coordinated ASW Exercises or TRACKEX events (or a combination of these
two activities).
At the request of NMFS, subsequent to the publication of the
proposed rule, the Navy provided refined estimates of the number of
humpback whales estimated to be taken as prorated from the NAEMO model.
These new estimates were based on 20 hours of MF1 MFAS occurring in the
Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas (outside
of 3 nmi and waters deeper than 60 m) during December through April.
The analysis assumed takes could occur in either of the two geographic
mitigation areas. The resulting take estimates provided by the Navy
were 2.12 takes by behavioral disturbance and 11.08 takes by TTS (a
total of 13.20 takes by Level B harassment). These take estimates
represent five ASW TRACKEX events with each event using four hours of
MF1 sonar. While other configurations of the 20 hours could occur, NMFS
and the Navy concur that five 4-hour exercises on five different days
best represents the likely scenario that allows for the most
appropriate take estimate. A single 4-hr TRACKEX event was expected to
result in 0.42 takes by behavioral disturbance and 2.2 takes by TTS (a
total of 2.62 takes by Level B harassment). However, the approach used
to calculate these take estimates did not adequately consider the
concentration of humpback whales found within these established
breeding and calving grounds from December through April.
NMFS conducted its own analysis of the take by Level A harassment
(by PTS) and Level B harassment (both TTS and behavioral disruption)
that could occur in the Chalan Kanoa Reef and Marpi Reef Geographic
Mitigation Areas under the 20-hr cap, for the purposes of both better
understanding the impacts to adults and calves in this important area
and modifying the total take numbers for humpback whales given more
granular survey data now being considered in this area. Our exposure
analysis is focused on the whales within the areas around Saipan
covered by the surveys conducted by the PIFSC and reported in the Hill
et al. (2020a) paper and the Hill et al. (2020b) abundance and density
report. We believe this approach more accurately estimates potential
exposures and takes of whales as a result of MF1 MFAS in these two
Geographic Mitigation Areas. More extensive mark/recapture data in this
smaller area provide a more granular and robust estimate of potential
abundance and density for this specific area than the density estimate
used by the Navy for the broader MITT Study Area. Estimates provided by
the PIFSC (Hill et al., 2020b) are preliminary, represent ``snapshots''
of abundance for that survey period based on the timing of the survey,
and may change--but these estimates represent the best available
scientific data for two reasons: (1) Estimates are area specific; and
(2) estimates are far more robust than a non-model approach (e.g.,
sightings per unit of effort approach).
We used an approach based on the annual abundance estimates from
the PIFSC report (Hill et al., 2020b) to derive estimates of animals
that may be exposed to MF1 MFAS within these two Geographic Mitigation
Areas. Preliminary annual (2015-2019) estimates of abundance, including
standard errors (SE), 95 percent confidence intervals (CI), and
densities of humpback whales in the PIFSC's study area were calculated
using mark-recapture analyses (Table 3 in Hill et al., 2020b).
Densities (whales/km\2\) are reported for the full survey area (839
km\2\) and the truncated survey area where most of the effort and all
of the humpback whale encounters occurred (384 km\2\) areas off the
west side of Saipan to Chalan Kanoa Reef and north to Marpi Reef. The
error associated with the average non-calf and total abundance was
obtained by summing the variances of the annual estimates even though
these estimates are not independent, as using a bootstrap or other
approach to estimate uncertainty was beyond the scope of this
preliminary analysis. The average non-calf abundance from 2015-2019 was
44 animals (Table 3 in Hill et al., 2020b). PIFSC provided estimates of
calf abundance in their annual abundance estimates by increasing the
average annual abundance of whales (non-calf) by the proportion of
calves seen in the four years of surveys where calves were seen (2015-
2018). The proportion of calves ranges from 0.5 to 0.2. This increased
the average number of animals (non-calf) from 44 to 61 (total abundance
(44) and 17 calves; with a 95 percent CI of 41-91) animals. Therefore,
we are conservatively estimating that 61 animals a day could be taken
on 5 days in which the exercise occurs for a total of 305 humpback
whales taken by Level B harassment annually in the two Geographic
Mitigation Areas combined (assuming 20 hrs of MF1 MFAS occurred). The
Navy provided updated NAEMO-based calculations (as described above)
that estimated 13 takes by Level B harassment during 20 hours of MF1
sonar. Subtracting these 13 takes from our estimate of 305 exposures
(takes) results in 292 animals based on the new abundance information.
Using the proportions of these takes as presented by the Navy estimated
take (12 percent behavioral and 88 percent TTS) results in an
additional 35 takes by behavioral disturbance and 257 takes by TTS
annually.
This is a greater number of takes and a more conservative approach
than the Navy's estimate and increases the total take by Level B
harassment, but also provides a more accurate representation of how
many takes by Level B harassment could occur during the breeding season
in the two Geographic Mitigation Areas. The maximum number of animals
(61) that could be taken in a day is a very conservative, worst-case
scenario estimate based on the best available abundance data for
humpback whales. We do not know how humpback whales move between the
two Geographic Mitigation Areas or if more whales may be present in one
Geographic Mitigation Area versus the other when the Navy is conducting
their activity. We also assume the Navy could engage in exercises that
only occur in one of two Geographic Mitigation Areas or it could be
split between the two areas and involve multiple ships. We also
acknowledge takes of humpback whales would certainly be less if the
Navy's MF1 MFAS use occurs at the beginning or toward the end of the
breeding season in the Geographic Mitigation Areas.
There is a very low likelihood that a humpback whale would
accumulate enough exposure to result in PTS in the two Geographic
Mitigation Areas. However, the Navy's approach to accounting for
avoidance does not address possible differences in avoidance capability
based on an animal's life-stage or particular life function at the time
of exposure. Mother-calf pairs on the calving grounds may be less
capable of avoiding additional exposures at levels that could cause
PTS, as compared to individual adult males or females without calves.
The age of the calf may also be a factor in the avoidance capability of
a mother-
[[Page 46366]]
calf pair (e.g., neonates may be particularly vulnerable). Mother-calf
pairs may respond differently to MF1 MFAS at close range. Other
potential stressors (e.g., presence of breeding males, other nearby
vessel activity, or potential predators) may influence how humpback
whales (including cow-calf pairs) respond to acoustic stressors.
Therefore, we estimate that up to one mother-calf pair of humpback
whales could be taken by Level A harassment by PTS over the total
seven-year period of the rule.
Additional mitigation by the Navy will include reporting of all
active sonar use (all bins, by bin) in the Marpi Reef and Chalan Kanoa
Geographic Mitigation Areas from December 1 through April 30. This will
provide NMFS with more specific data in order to evaluate sonar use
with current mitigation measures in the Geographic Mitigation Areas and
to determine if any changes are needed through Adaptive Management.
Summary of Estimated Take From Training and Testing Activities
Based on the methods discussed in the previous sections and the
Navy's model and quantitative assessment of mitigation, the Navy
provided its take estimate and request for authorization of takes
incidental to the use of acoustic and explosive sources for training
and testing activities both annually (based on the maximum number of
activities that could occur per 12-month period) and over the seven-
year period covered by the Navy's rulemaking/LOA application. NMFS has
reviewed the Navy's data, methodology, and analysis and determined that
it is complete and accurate. NMFS agrees that the estimates for
incidental takes by harassment from all sources requested for
authorization are the maximum number of instances in which marine
mammals are reasonably expected to be taken.
For training and testing activities, Table 28 summarizes the Navy's
take estimate and request and includes the maximum amount of Level A
harassment and Level B harassment annually and for the seven-year
period that NMFS concurs is reasonably likely to occur by species. Note
that take by Level B harassment includes both behavioral disturbance
and TTS. Tables 6.4-13 through 6.4-38 in Section 6 of the Navy's
rulemaking/LOA application provide the comparative amounts of TTS and
behavioral disturbance for each species annually, noting that if a
modeled marine mammal was ``taken'' through exposure to both TTS and
behavioral disruption in the model, it was recorded as a TTS.
Table 28--Annual and Seven-Year Total Species-Specific Take Estimates Authorized From Acoustic and Explosive
Sound Source Effects for All Training and Testing Activities in the MITT Study Area
----------------------------------------------------------------------------------------------------------------
Annual 7-Year total \1\
---------------------------------------------------------------
Species Level B Level A Level B Level A
harassment harassment harassment harassment
----------------------------------------------------------------------------------------------------------------
Mysticetes
Blue whale *................................ 24 0 169 0
Bryde's whale............................... 298 0 2,078 0
Fin whale *................................. 25 0 173 0
Humpback whale *............................ 771 0 3,348 ** 1
Minke whale................................. 95 0 665 0
Omura's whale............................... 29 0 199 0
Sei whale*.................................. 155 0 1,083 0
Odontocetes
Blainville's beaked whale................... 1,718 0 12,033 0
Bottlenose dolphin.......................... 137 0 961 0
Cuvier's beaked whale....................... 646 0 4,529 0
Dwarf sperm whale........................... 8,499 50 59,459 341
False killer whale.......................... 762 0 5,331 0
Fraser's dolphin............................ 13,278 1 92,931 8
Ginkgo-toothed beaked whale................. 3,726 0 26,088 0
Killer whale................................ 44 0 309 0
Longman's beaked whale...................... 6,066 0 42,487 0
Melon-headed whale.......................... 2,815 0 19,691 0
Pantropical spotted dolphin................. 14,896 1 104,242 7
Pygmy killer whale.......................... 104 0 726 0
Pygmy sperm whale........................... 3,410 19 23,853 136
Risso's dolphin............................. 3,170 0 22,179 0
Rough-toothed dolphin....................... 197 0 1,379 0
Short-finned pilot whale.................... 1,163 0 8,140 0
Sperm whale *............................... 203 0 1,420 0
Spinner dolphin............................. 1,414 1 9,896 4
Striped dolphin............................. 4,007 0 28,038 0
----------------------------------------------------------------------------------------------------------------
* ESA-listed species within the MITT Study Area.
** There is one mother-calf pair of humpback whales estimated to be taken by Level A harassment by PTS over the
period of the rule. See the Estimated Take of Marine Mammals section for further details.
\1\ The 7-year totals may be less than the annual totals times seven, given that not all activities occur every
year, some activities occur multiple times within a year, and some activities only occur a few times over the
course of a 7-year period.
Mitigation Measures
Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the
permissible methods of taking pursuant to the activity, and other means
of effecting the least practicable adverse impact on the species or
stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance, and on the
availability of the species or stocks for subsistence uses (``least
practicable
[[Page 46367]]
adverse impact''). NMFS does not have a regulatory definition for least
practicable adverse impact. The 2004 NDAA amended the MMPA as it
relates to military readiness activities and the incidental take
authorization process such that a determination of ``least practicable
adverse impact'' shall include consideration of personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity.
In Conservation Council for Hawaii v. National Marine Fisheries
Service, 97 F. Supp.3d 1210, 1229 (D. Haw. 2015), the Court stated that
NMFS ``appear[s] to think [it] satisf[ies] the statutory `least
practicable adverse impact' requirement with a `negligible impact'
finding.'' More recently, expressing similar concerns in a challenge to
a U.S. Navy Surveillance Towed Array Sensor System Low Frequency Active
Sonar (SURTASS LFA) incidental take rule (77 FR 50290), the Ninth
Circuit Court of Appeals in Natural Resources Defense Council (NRDC) v.
Pritzker, 828 F.3d 1125, 1134 (9th Cir. 2016), stated, ``[c]ompliance
with the `negligible impact' requirement does not mean there [is]
compliance with the `least practicable adverse impact' standard.'' As
the Ninth Circuit noted in its opinion, however, the Court was
interpreting the statute without the benefit of NMFS' formal
interpretation. We state here explicitly that NMFS is in full agreement
that the ``negligible impact'' and ``least practicable adverse impact''
requirements are distinct, even though both statutory standards refer
to species and stocks. With that in mind, we provide further
explanation of our interpretation of least practicable adverse impact,
and explain what distinguishes it from the negligible impact standard.
This discussion is consistent with previous rules we have issued, such
as the Navy's HSTT rule (83 FR 66846; December 27, 2018), Atlantic
Fleet Training and Testing rule (84 FR 70712; December 23, 2019), and
the Northwest Training and Testing (NWTT) proposed rule (0648-BJ30;
June 02, 2020).
Before NMFS can issue incidental take regulations under section
101(a)(5)(A) of the MMPA, it must make a finding that the total taking
will have a ``negligible impact'' on the affected ``species or stocks''
of marine mammals. NMFS' and U.S. Fish and Wildlife Service's
implementing regulations for section 101(a)(5) both define ``negligible
impact'' as an impact resulting from the specified activity that cannot
be reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival (50 CFR 216.103 and 50 CFR 18.27(c)).
Recruitment (i.e., reproduction) and survival rates are used to
determine population growth rates \2\ and therefore are considered in
evaluating population level impacts.
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\2\ A growth rate can be positive, negative, or flat.
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As stated in the preamble to the proposed rule for the MMPA
incidental take implementing regulations, not every population-level
impact violates the negligible impact requirement. The negligible
impact standard does not require a finding that the anticipated take
will have ``no effect'' on population numbers or growth rates: The
statutory standard does not require that the same recovery rate be
maintained, rather that no significant effect on annual rates of
recruitment or survival occurs. The key factor is the significance of
the level of impact on rates of recruitment or survival. (54 FR 40338,
40341-42; September 29, 1989).
While some level of impact on population numbers or growth rates of
a species or stock may occur and still satisfy the negligible impact
requirement--even without consideration of mitigation--the least
practicable adverse impact provision separately requires NMFS to
prescribe means of effecting the least practicable adverse impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, 50 CFR
216.102(b), which are typically identified as mitigation measures.\3\
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\3\ For purposes of this discussion, we omit reference to the
language in the standard for least practicable adverse impact that
says we also must mitigate for subsistence impacts because they are
not at issue in this rule.
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The negligible impact and least practicable adverse impact
standards in the MMPA both call for evaluation at the level of the
``species or stock.'' The MMPA does not define the term ``species.''
However, Merriam-Webster Dictionary defines ``species'' to include
``related organisms or populations potentially capable of
interbreeding.'' See www.merriam-webster.com/dictionary/species
(emphasis added). Section 3(11) of the MMPA defines ``stock'' as a
group of marine mammals of the same species or smaller taxa in a common
spatial arrangement that interbreed when mature. The definition of
``population'' is a group of interbreeding organisms that represents
the level of organization at which speciation begins. www.merriam-webster.com/dictionary/population. The definition of ``population'' is
strikingly similar to the MMPA's definition of ``stock,'' with both
definitions involving groups of individuals that belong to the same
species and that are located in a manner that allows for interbreeding.
In fact under MMPA section 3(11), the term ``stock'' in the MMPA is
interchangeable with the statutory term ``population stock.'' Both the
negligible impact standard and the least practicable adverse impact
standard call for evaluation at the level of the species or stock, and
the terms ``species'' and ``stock'' both relate to populations;
therefore, it is appropriate to view both the negligible impact
standard and the least practicable adverse impact standard as having a
population-level focus.
This interpretation is consistent with Congress' statutory findings
for enacting the MMPA, nearly all of which are most applicable at the
species or stock (i.e., population) level. See MMPA section 2 (finding
that it is species and population stocks that are or may be in danger
of extinction or depletion; that it is species and population stocks
that should not diminish beyond being significant functioning elements
of their ecosystems; and that it is species and population stocks that
should not be permitted to diminish below their optimum sustainable
population level). Annual rates of recruitment (i.e., reproduction) and
survival are the key biological metrics used in the evaluation of
population-level impacts, and accordingly these same metrics are also
used in the evaluation of population level impacts for the least
practicable adverse impact standard.
Recognizing this common focus of the least practicable adverse
impact and negligible impact provisions on the ``species or stock''
does not mean we conflate the two standards; despite some common
statutory language, we recognize the two provisions are different and
have different functions. First, a negligible impact finding is
required before NMFS can issue an incidental take authorization.
Although it is acceptable to use the mitigation measures to reach a
negligible impact finding (see 50 CFR 216.104(c)), no amount of
mitigation can enable NMFS to issue an incidental take authorization
for an activity that still would not meet the negligible impact
standard. Moreover, even where NMFS can reach a negligible impact
finding--which we emphasize does allow for the possibility of some
``negligible'' population-level impact--the agency must still prescribe
measures that will effect the least practicable amount of adverse
impact upon the affected species or stock.
Section 101(a)(5)(A)(i)(II) requires NMFS to issue, in conjunction
with its authorization, binding--and
[[Page 46368]]
enforceable--restrictions (in the form of regulations) setting forth
how the activity must be conducted, thus ensuring the activity has the
``least practicable adverse impact'' on the affected species or stocks.
In situations where mitigation is specifically needed to reach a
negligible impact determination, section 101(a)(5)(A)(i)(II) also
provides a mechanism for ensuring compliance with the ``negligible
impact'' requirement. Finally, the least practicable adverse impact
standard also requires consideration of measures for marine mammal
habitat, with particular attention to rookeries, mating grounds, and
other areas of similar significance, and for subsistence impacts,
whereas the negligible impact standard is concerned solely with
conclusions about the impact of an activity on annual rates of
recruitment and survival.\4\ In NRDC v. Pritzker, the Court stated,
``[t]he statute is properly read to mean that even if population levels
are not threatened significantly, still the agency must adopt
mitigation measures aimed at protecting marine mammals to the greatest
extent practicable in light of military readiness needs.'' Pritzker at
1134 (emphases added). This statement is consistent with our
understanding stated above that even when the effects of an action
satisfy the negligible impact standard (i.e., in the Court's words,
``population levels are not threatened significantly''), still the
agency must prescribe mitigation under the least practicable adverse
impact standard. However, as the statute indicates, the focus of both
standards is ultimately the impact on the affected ``species or
stock,'' and not solely focused on or directed at the impact on
individual marine mammals.
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\4\ Outside of the military readiness context, mitigation may
also be appropriate to ensure compliance with the ``small numbers''
language in MMPA sections 101(a)(5)(A) and (D).
---------------------------------------------------------------------------
We have carefully reviewed and considered the Ninth Circuit's
opinion in NRDC v. Pritzker in its entirety. While the Court's
reference to ``marine mammals'' rather than ``marine mammal species or
stocks'' in the italicized language above might be construed as a
holding that the least practicable adverse impact standard applies at
the individual ``marine mammal'' level, i.e., that NMFS must require
mitigation to minimize impacts to each individual marine mammal unless
impracticable, we believe such an interpretation reflects an incomplete
appreciation of the Court's holding. In our view, the opinion as a
whole turned on the Court's determination that NMFS had not given
separate and independent meaning to the least practicable adverse
impact standard apart from the negligible impact standard, and further,
that the Court's use of the term ``marine mammals'' was not addressing
the question of whether the standard applies to individual animals as
opposed to the species or stock as a whole. We recognize that while
consideration of mitigation can play a role in a negligible impact
determination, consideration of mitigation measures extends beyond that
analysis. In evaluating what mitigation measures are appropriate, NMFS
considers the potential impacts of the Specified Activities, the
availability of measures to minimize those potential impacts, and the
practicability of implementing those measures, as we describe below.
Implementation of Least Practicable Adverse Impact Standard
Given the NRDC v. Pritzker decision, we discuss here how we
determine whether a measure or set of measures meets the ``least
practicable adverse impact'' standard. Our separate analysis of whether
the take anticipated to result from the Navy's activities meets the
``negligible impact'' standard appears in the Analysis and Negligible
Impact Determination section below.
Our evaluation of potential mitigation measures includes
consideration of two primary factors:
(1) The manner in which, and the degree to which, implementation of
the potential measure(s) is expected to reduce adverse impacts to
marine mammal species or stocks, their habitat, and their availability
for subsistence uses (where relevant). This analysis considers such
things as the nature of the potential adverse impact (such as
likelihood, scope, and range), the likelihood that the measure will be
effective if implemented, and the likelihood of successful
implementation; and
(2) The practicability of the measures for applicant
implementation. Practicability of implementation may consider such
things as cost, impact on activities, and, in the case of a military
readiness activity, specifically considers personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity.
While the language of the least practicable adverse impact standard
calls for minimizing impacts to affected species or stocks, we
recognize that the reduction of impacts to those species or stocks
accrues through the application of mitigation measures that limit
impacts to individual animals. Accordingly, NMFS' analysis focuses on
measures that are designed to avoid or minimize impacts on individual
marine mammals that are likely to increase the probability or severity
of population-level effects.
While direct evidence of impacts to species or stocks from a
specified activity is rarely available, and additional study is still
needed to understand how specific disturbance events affect the fitness
of individuals of certain species, there have been improvements in
understanding the process by which disturbance effects are translated
to the population. With recent scientific advancements (both marine
mammal energetic research and the development of energetic frameworks),
the relative likelihood or degree of impacts on species or stocks may
often be inferred given a detailed understanding of the activity, the
environment, and the affected species or stocks--and the best available
science has been used here. This same information is used in the
development of mitigation measures and helps us understand how
mitigation measures contribute to lessening effects (or the risk
thereof) to species or stocks. We also acknowledge that there is always
the potential that new information, or a new recommendation could
become available in the future and necessitate reevaluation of
mitigation measures (which may be addressed through adaptive
management) to see if further reductions of population impacts are
possible and practicable.
In the evaluation of specific measures, the details of the
specified activity will necessarily inform each of the two primary
factors discussed above (expected reduction of impacts and
practicability), and are carefully considered to determine the types of
mitigation that are appropriate under the least practicable adverse
impact standard. Analysis of how a potential mitigation measure may
reduce adverse impacts on a marine mammal stock or species,
consideration of personnel safety, practicality of implementation, and
consideration of the impact on effectiveness of military readiness
activities are not issues that can be meaningfully evaluated through a
yes/no lens. The manner in which, and the degree to which,
implementation of a measure is expected to reduce impacts, as well as
its practicability in terms of these considerations, can vary widely.
For example, a time/area restriction could be of very high value for
decreasing population-level impacts (e.g., avoiding disturbance of
feeding females in an area of established biological importance) or it
could be of
[[Page 46369]]
lower value (e.g., decreased disturbance in an area of high
productivity but of less biological importance). Regarding
practicability, a measure might involve restrictions in an area or time
that impedes the Navy's ability to certify a strike group (higher
impact on mission effectiveness and national security), or it could
mean delaying a small in-port training event by 30 minutes to avoid
exposure of a marine mammal to injurious levels of sound (lower
impact). A responsible evaluation of ``least practicable adverse
impact'' will consider the factors along these realistic scales.
Accordingly, the greater the likelihood that a measure will contribute
to reducing the probability or severity of adverse impacts to the
species or stock or its habitat, the greater the weight that measure is
given when considered in combination with practicability to determine
the appropriateness of the mitigation measure, and vice versa. We
discuss consideration of these factors in greater detail below.
1. Reduction of adverse impacts to marine mammal species or stocks
and their habitat.\5\ The emphasis given to a measure's ability to
reduce the impacts on a species or stock considers the degree,
likelihood, and context of the anticipated reduction of impacts to
individuals (and how many individuals) as well as the status of the
species or stock.
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\5\ We recognize the least practicable adverse impact standard
requires consideration of measures that will address minimizing
impacts on the availability of the species or stocks for subsistence
uses where relevant. Because subsistence uses are not implicated for
this action, we do not discuss them. However, a similar framework
would apply for evaluating those measures, taking into account the
MMPA's directive that we make a finding of no unmitigable adverse
impact on the availability of the species or stocks for taking for
subsistence, and the relevant implementing regulations.
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The ultimate impact on any individual from a disturbance event
(which informs the likelihood of adverse species- or stock-level
effects) is dependent on the circumstances and associated contextual
factors, such as duration of exposure to stressors. Though any proposed
mitigation needs to be evaluated in the context of the specific
activity and the species or stocks affected, measures with the
following types of effects have greater value in reducing the
likelihood or severity of adverse species- or stock-level impacts:
Avoiding or minimizing injury or mortality; limiting interruption of
known feeding, breeding, mother/young, or resting behaviors; minimizing
the abandonment of important habitat (temporally and spatially);
minimizing the number of individuals subjected to these types of
disruptions; and limiting degradation of habitat. Mitigating these
types of effects is intended to reduce the likelihood that the activity
will result in energetic or other types of impacts that are more likely
to result in reduced reproductive success or survivorship. It is also
important to consider the degree of impacts that are expected in the
absence of mitigation in order to assess the added value of any
potential measures. Finally, because the least practicable adverse
impact standard gives NMFS discretion to weigh a variety of factors
when determining appropriate mitigation measures and because the focus
of the standard is on reducing impacts at the species or stock level,
the least practicable adverse impact standard does not compel
mitigation for every kind of take, or every individual taken, if that
mitigation is unlikely to meaningfully contribute to the reduction of
adverse impacts on the species or stock and its habitat, even when
practicable for implementation by the applicant.
The status of the species or stock is also relevant in evaluating
the appropriateness of potential mitigation measures in the context of
least practicable adverse impact. The following are examples of factors
that may (either alone, or in combination) result in greater emphasis
on the importance of a mitigation measure in reducing impacts on a
species or stock: The stock is known to be decreasing or status is
unknown, but believed to be declining; the known annual mortality (from
any source) is approaching or exceeding the potential biological
removal (PBR) level (as defined in MMPA section 3(20)); the affected
species or stock is a small, resident population; or the stock is
involved in a UME or has other known vulnerabilities, such as
recovering from an oil spill.
Habitat mitigation, particularly as it relates to rookeries, mating
grounds, and areas of similar significance, is also relevant to
achieving the standard and can include measures such as reducing
impacts of the activity on known prey utilized in the activity area or
reducing impacts on physical habitat. As with species- or stock-related
mitigation, the emphasis given to a measure's ability to reduce impacts
on a species or stock's habitat considers the degree, likelihood, and
context of the anticipated reduction of impacts to habitat. Because
habitat value is informed by marine mammal presence and use, in some
cases there may be overlap in measures for the species or stock and for
use of habitat.
We consider available information indicating the likelihood of any
measure to accomplish its objective. If evidence shows that a measure
has not typically been effective nor successful, then either that
measure should be modified or the potential value of the measure to
reduce effects should be lowered.
2. Practicability. Factors considered may include cost, impact on
activities, and, in the case of a military readiness activity, will
include personnel safety, practicality of implementation, and impact on
the effectiveness of the military readiness activity (see MMPA section
101(a)(5)(A)(ii)).
Assessment of Mitigation Measures for the MITT Study Area
Section 216.104(a)(11) of NMFS' implementing regulations requires
an applicant for incidental take authorization to include in its
request, among other things, ``the availability and feasibility
(economic and technological) of equipment, methods, and manner of
conducting such activity or other means of effecting the least
practicable adverse impact upon the affected species or stocks, their
habitat, and [where applicable] on their availability for subsistence
uses, paying particular attention to rookeries, mating grounds, and
areas of similar significance.'' Thus NMFS' analysis of the sufficiency
and appropriateness of an applicant's measures under the least
practicable adverse impact standard will always begin with evaluation
of the mitigation measures presented in the application.
NMFS has fully reviewed the specified activities and the mitigation
measures included in the Navy's rulemaking/LOA application and the 2020
MITT FSEIS/OEIS to determine if the mitigation measures would result in
the least practicable adverse impact on marine mammals and their
habitat. NMFS worked with the Navy in the development of the Navy's
initially proposed measures, which were informed by years of
implementation and monitoring. A complete discussion of the Navy's
evaluation process used to develop, assess, and select mitigation
measures, which was informed by input from NMFS, can be found in
Section 5 (Mitigation) and Appendix I (Geographic Mitigation
Assessment) of the 2020 MITT FSEIS/OEIS. The process described in
Section 5 (Mitigation) and Appendix I (Geographic Mitigation
Assessment) of the 2020 MITT FSEIS/OEIS robustly supported NMFS'
independent evaluation of whether the mitigation measures meet the
least practicable adverse impact standard.
As a general matter, where an applicant proposes measures that are
likely to reduce impacts to marine
[[Page 46370]]
mammals, the fact that they are included in the application indicates
that the measures are practicable, and it is not necessary for NMFS to
conduct a detailed analysis of the measures the applicant proposed
(rather, they are simply included). We note that in their application,
the Navy added three geographic mitigation areas with accompanying
mitigation measures that are new since the 2015-2020 MITT incidental
take regulations: (1) Marpi Reef Geographic Mitigation Area--to avoid
potential impacts from explosives on marine mammals and report hours of
MFAS-MF1 within the mitigation area, which contains a seasonal presence
of humpback whales (2) Chalan Kanoa Reef Geographic Mitigation Area--to
avoid potential impacts from explosives on marine mammals and report
hours of MFAS-MF1 within the mitigation area, which contains a seasonal
presence of humpback whales, and (3) Agat Bay Nearshore Geographic
Mitigation Area--to avoid potential impacts from explosives and MFAS-
MF1 on spinner dolphins.
However, it is still necessary for NMFS to consider whether there
are additional practicable measures that would meaningfully reduce the
probability or severity of impacts that could affect reproductive
success or survivorship. In the case of this rule, we worked with the
Navy after it submitted its 2019 rulemaking/LOA application but prior
to the development of the proposed rule to expand the mitigation areas
for Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas to
more fully encompass the 400-m isobaths based on the available data
indicating the presence of humpback whale mother/calf pairs (seasonal
breeding area), which is expected to further avoid impacts from
explosives that would be more likely to affect reproduction or survival
of individuals and could adversely impact the species. The Navy will
also implement the Marpi Reef and Chalan Kanoa Reef Awareness
Notification Message Area, which require Navy personnel to broadcast
the seasonal presence of humpback whales, further minimizing any
potential impacts from vessel strikes during training and testing
activities as these areas contain important seasonal breeding habitat
for this species.
In addition, since publication of the proposed rule, and in
consideration of public comments received, NMFS and the Navy have
agreed to include additional mitigation requirements that will further
reduce the likelihood and/or severity of adverse impacts on marine
mammal species and their habitat and are practicable for
implementation. Below we describe the added measures that the Navy will
implement and explain the manner in which they are expected to reduce
the likelihood or severity of adverse impacts on humpback whales and
their habitat.
1. Cap on MF1 mid-frequency active sonar use in the Chalan Kanoa
and Marpi Reef Geographic Mitigation Areas. The Navy will implement an
annual 20-hour cap from December 1 through April 30 on surface ship
hull-mounted MF1 mid-frequency active sonar within the Chalan Kanoa
Reef and Marpi Reef Geographic Mitigation Areas to reduce impacts to
humpback whales while allowing the Navy to retain critical shallow
water training flexibility within the MITT Study Area. This cap on
activities (MF1 sonar) in these areas with higher concentrations of
humpback whales engaged in important reproductive behaviors is expected
to reduce the probability or severity of impacts on humpback whales
that would be more likely to adversely affect the reproduction or
survival of any individual, which in turn reduces the likelihood that
any impacts would translate to adverse impacts on the species.
2. Additional reporting of sonar sources in the Chalan Kanoa and
Marpi Reef Geographic Mitigation Areas. In addition to the reporting of
the total hours of surface ship hull-mounted MF1 mid-frequency active
sonar, the Navy will also report all sonar sources used (all bins, by
bin) within the Chalan Kanoa and Marpi Reef Geographic Mitigation Areas
from December 1 to April 30 in the annual MITT classified Exercise
Reports. This will allow NMFS to evaluate sonar use specifically in
these areas with higher concentrations of humpback whales and determine
if further mitigation is needed through Adaptive Management.
Overall the Navy has agreed to procedural mitigation measures that
will reduce the probability and/or severity of impacts expected to
result from acute exposure to acoustic sources and explosives, ship
strike, and impacts to marine mammal habitat. Specifically, the Navy
will use a combination of delayed starts, powerdowns, and shutdowns to
avoid mortality or serious injury, minimize the likelihood or severity
of PTS or other injury, and reduce instances of TTS or more severe
behavioral disruption caused by acoustic sources or explosives. The
Navy will also implement multiple time/area restrictions that will
reduce take of marine mammals in areas or at times where they are known
to engage in important behaviors, such as calving, where the disruption
of those behaviors would have a higher probability of resulting in
impacts on reproduction or survival of individuals that could lead to
population-level impacts.
The Navy assessed the practicability of these measures in the
context of personnel safety, practicality of implementation, and their
impacts on the Navy's ability to meet their Title 10 requirements and
found that the measures are supportable. As described in more detail
below, NMFS has independently evaluated the measures the Navy proposed
in the manner described earlier in this section (i.e., in consideration
of their ability to reduce adverse impacts on marine mammal species and
their habitat and their practicability for implementation). We have
determined that the measures will significantly and adequately reduce
impacts on the affected marine mammal species and their habitat and,
further, be practicable for Navy implementation. Therefore, the
mitigation measures assure that Navy's activities will have the least
practicable adverse impact on the species and their habitat.
Measures Evaluated But Not Included
The Navy also evaluated numerous measures in the 2020 MITT FSEIS/
OEIS that were not included in the Navy's rulemaking/LOA application,
and NMFS independently reviewed and concurs with the Navy's analysis
that their inclusion was not appropriate under the least practicable
adverse impact standard based on our assessment. The Navy considered
these additional potential mitigation measures in two groups. First,
Section 5 (Mitigation) of the 2020 MITT FSEIS/OEIS, in the Measures
Considered but Eliminated section, includes an analysis of an array of
different types of mitigation that have been recommended over the years
by non-governmental organizations or the public, through scoping or
public comment on environmental compliance documents. Appendix I
(Geographic Mitigation Assessment) of the 2020 MITT FSEIS/OEIS includes
an in-depth analysis of time/area restrictions that have been
recommended over time. As described in Section 5 (Mitigation) of the
2020 MITT FSEIS/OEIS, commenters sometimes recommend that the Navy
reduce its overall amount of training and testing, reduce explosive
use, modify its sound sources, completely replace live training and
testing with computer simulation, or include time of day restrictions.
Many of these mitigation measures could potentially reduce the number
of marine mammals taken, via direct reduction of the
[[Page 46371]]
activities or amount of sound energy put in the water. However, as
described in Section 5 (Mitigation) of the 2020 MITT FSEIS/OEIS, the
Navy needs to train and test in the conditions in which it fights--and
these types of modifications fundamentally change the activity in a
manner that will not support the purpose and need for the training and
testing (i.e., are entirely impracticable) and therefore are not
considered further. NMFS finds the Navy's explanation for why adoption
of these recommendations will unacceptably undermine the purpose of the
testing and training persuasive. After independent review, NMFS finds
Navy's judgment on the impacts of these potential mitigation measures
to personnel safety, practicality of implementation, and the
effectiveness of training and testing within the MITT Study Area
persuasive, and for these reasons, NMFS finds that these measures do
not meet the least practicable adverse impact standard because they are
not practicable.
Second, in Section 5 (Mitigation) of the 2020 MITT FSEIS/OEIS, the
Navy evaluated additional potential procedural mitigation measures,
including increased mitigation zones, ramp-up measures, additional
passive acoustic and visual monitoring, and decreased vessel speeds.
Some of these measures have the potential to incrementally reduce take
to some degree in certain circumstances, though the degree to which
this would occur is typically low or uncertain. However, as described
in the Navy's analysis, the measures would have significant direct
negative effects on mission effectiveness and are impracticable (see
Section 5 Mitigation of 2020 MITT FSEIS/OEIS). NMFS independently
reviewed the Navy's evaluation and concurs with this assessment, which
supports NMFS' findings that the impracticability of this additional
mitigation would greatly outweigh any potential minor reduction in
marine mammal impacts that might result; therefore, these additional
mitigation measures are not warranted.
Last, Appendix I (Geographic Mitigation Assessment) of the 2020
MITT FSEIS/OEIS describes a comprehensive method for analyzing
potential geographic mitigation that includes consideration of both a
biological assessment of how the potential time/area limitation would
benefit the species and its habitat (e.g., is a key area of biological
importance or would result in avoidance or reduction of impacts) in the
context of the stressors of concern in the specific area and an
operational assessment of the practicability of implementation
(including an assessment of the specific importance of that area for
training, considering proximity to training ranges and emergency
landing fields and other issues). For most of the areas that were
considered in the 2020 MITT FSEIS/OEIS but not included as mitigation
in this rule, the Navy found that the mitigation was not warranted
because the anticipated reduction of adverse impacts on marine mammal
species and their habitat was not sufficient to offset the
impracticability of implementation. In some cases, potential benefits
to marine mammals were non-existent, while in others the consequences
on mission effectiveness were too great.
NMFS has reviewed the analysis in Section 5 (Mitigation) and
Appendix I (Geographic Mitigation Assessment) of the 2020 MITT FSEIS/
OEIS, which considers the same factors that NMFS considers under the
MMPA to satisfy the least practicable adverse impact standard, and
concurs with the analysis and conclusions. Therefore, NMFS is not
including any of the measures that the Navy ruled out in the 2020 MITT
FSEIS/OEIS.
Below, we describe additional measures that were considered but
eliminated during the development of the final rule: (1) A full
restriction on MF1 sonar use in the Marpi Reef and Chalan Kanoa Reef
Geographic Mitigation Areas (versus the 20-hour annual cap between
December 1 and April 30) and (2) measures to further minimize any
potential risk that beaked whales would strand as a result of Navy
training and testing activities.
Regarding the consideration of a full restriction on MF1 sonar use
in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas,
areas of shallow depths, which are important for certain types of
training, are limited in the Mariana Archipelago, and the Navy
determined it would be impractical to completely limit the use of sonar
at Chalan Kanoa Reef and Marpi Reef. The Navy provided additional
analysis to NMFS that these two Geographic Mitigation Areas account for
up to 14.3 percent of all shallow water areas less than 200 m and
outside of 3 nmi in the MITT Study Area (generally surrounding land),
and up to 22 percent of all shallow water areas less than 200 m and
outside of 3 nmi (generally surrounding land) and south (not inclusive)
of Farallon De Medinilla in the MITT Study Area. NMFS agreed with these
calculations. The Navy has stressed the broader need for flexibility as
well as the specific need not to restrict training areas entirely in
this part of the MITT Study Area given the proximity to forward
deployed operations (i.e., U.S. 7th fleet's continuous presence in the
Indo-Pacific region, which is a National Defense Strategy priority
theater of operations) and the need to have the option to conduct
training quickly and to respond to emergent national security threats.
Given the reductions in potential impacts already provided by the full
restriction on explosive use and the 20-hour annual cap on MF1 sonar in
the areas between December 1 and April 30, combined with the
impracticability for the Navy, NMFS found that this measure was not
warranted.
In addition, NMFS had thorough discussions with the Navy about the
possibility of crafting a mitigation measure to minimize the potential
risk that Navy activities could contribute in any way to the potential
stranding of beaked whales. These discussions included consideration of
all public comments which recommended beaked whale mitigation measures.
However, despite years of field surveys conducted under interagency
agreements between the Navy and NMFS' PIFSC along with Navy-funded
beaked whale monitoring, there remains a lack of scientific information
available on beaked whale distribution and other essential species
information in the Mariana Islands. Without sufficient scientific data
on beaked whale habitat use, bathymetry, and seasonality, and from that
a better understanding of the circumstances that could affect the
likelihood of a stranding in the MITT Study Area, NMFS is unable to
develop mitigation measures that would meaningfully reduce the
likelihood of stranding and/or will not result in unreasonable
operational/practicability concerns. Consequently, NMFS recommended to
the Navy that the two agencies convene a panel of experts, both from
the region, as well as beaked whale behavioral response experts from
other geographic areas, and Navy experts on biology, operations, and
mitigation to review the status of the science, identify data gaps, and
identify information applicable for consideration for future mitigation
through the Adaptive Management process. The Navy has agreed to fund
and co-organize this effort. Additional measures that the Navy has
agreed to conduct to increase understanding and decrease uncertainty
around beaked whales in the MITT Study Area are discussed in the
Monitoring section.
The following sections describe the mitigation measures that will
be implemented in association with the training and testing activities
analyzed in this document. These are the mitigation measures that NMFS
has determined will ensure the least
[[Page 46372]]
practicable adverse impact on all affected species and their habitat,
including the specific considerations for military readiness
activities. The mitigation measures are organized into two categories:
Procedural mitigation and mitigation areas.
Procedural Mitigation
Procedural mitigation is mitigation that the Navy will implement
whenever and wherever an applicable training or testing activity takes
place within the MITT Study Area. The Navy customizes procedural
mitigation for each applicable activity category or stressor.
Procedural mitigation generally involves: (1) The use of one or more
trained Lookouts to diligently observe for specific biological
resources (including marine mammals) within a mitigation zone, (2)
requirements for Lookouts to immediately communicate sightings of
specific biological resources to the appropriate watch station for
information dissemination, and (3) requirements for the watch station
to implement mitigation (e.g., halt an activity) until certain
recommencement conditions have been met. The first procedural
mitigation measures (Table 29) are designed to train Lookouts and other
applicable Navy personnel in their observation, environmental
compliance, and reporting responsibilities. The remainder of the
procedural mitigation measures (Tables 30 through 46) are organized by
stressor type and activity category and includes acoustic stressors
(i.e., active sonar, weapons firing noise), explosive stressors (i.e.,
sonobuoys, torpedoes, medium-caliber and large-caliber projectiles,
missiles and rockets, bombs, sinking exercises, mines, anti-swimmer
grenades), and physical disturbance and strike stressors (i.e., vessel
movement; towed in-water devices; small-, medium-, and large-caliber
non-explosive practice munitions; non-explosive missiles and rockets,
non-explosive bombs and mine shapes). Note that the procedural
mitigation measures for other incidental take regulations in Navy study
areas, such as AFTT and HSTT, require that Lookouts observe for
floating vegetation in addition to marine mammals because floating
vegetation has high ecological protection value (e.g., habitat for
juvenile/hatchling sea turtles, potential foraging habitat for marine
mammals). The term ``floating vegetation'' in those regulations
referred specifically to floating concentrations of detached kelp
paddies (off the U.S. West Coast) and sargassum mats (off the U.S. East
Coast). However, in the MITT Study Area there are no floating
vegetation concentrations so that was not included in the procedural
mitigation measures in this rule.
Table 29--Procedural Mitigation for Environmental Awareness and
Education
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
All training and testing activities, as applicable.
Mitigation Requirements:
Appropriate Navy personnel (including civilian personnel) involved
in mitigation and training or testing activity reporting under the
specified activities will complete one or more modules of the U.S.
Navy Afloat Environmental Compliance Training Series, as identified
in their career path training plan. Modules include:
--Introduction to the U.S. Navy Afloat Environmental Compliance
Training Series. The introductory module provides information
on environmental laws (e.g., Endangered Species Act, Marine
Mammal Protection Act) and the corresponding responsibilities
that are relevant to Navy training and testing activities. The
material explains why environmental compliance is important in
supporting the Navy's commitment to environmental stewardship.
--Marine Species Awareness Training. All bridge watch personnel,
Commanding Officers, Executive Officers, maritime patrol
aircraft aircrews, anti[hyphen]submarine warfare and mine
warfare rotary-wing aircrews, Lookouts, and equivalent civilian
personnel must successfully complete the Marine Species
Awareness Training prior to standing watch or serving as a
Lookout. The Marine Species Awareness Training provides
information on sighting cues, visual observation tools and
techniques, and sighting notification procedures. Navy
biologists developed Marine Species Awareness Training to
improve the effectiveness of visual observations for biological
resources, focusing on marine mammals and sea turtles, and
including floating vegetation, jellyfish aggregations, and
flocks of seabirds.
--U.S. Navy Protective Measures Assessment Protocol. This module
provides the necessary instruction for accessing mitigation
requirements during the event planning phase using the
Protective Measures Assessment Protocol software tool.
--U.S. Navy Sonar Positional Reporting System and Marine Mammal
Incident Reporting. This module provides instruction on the
procedures and activity reporting requirements for the Sonar
Positional Reporting System and marine mammal incident
reporting.
------------------------------------------------------------------------
Table 30--Procedural Mitigation for Active Sonar
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Low-frequency active sonar, mid-frequency active sonar,
high-frequency active sonar:
--For vessel-based active sonar activities, mitigation applies
only to sources that are positively controlled and deployed
from manned surface vessels (e.g., sonar sources towed from
manned surface platforms).
--For aircraft-based active sonar activities, mitigation applies
only to sources that are positively controlled and deployed
from manned aircraft that do not operate at high altitudes
(e.g., rotary-wing aircraft). Mitigation does not apply to
active sonar sources deployed from unmanned aircraft or
aircraft operating at high altitudes (e.g., maritime patrol
aircraft).
Number of Lookouts and Observation Platform:
Hull-mounted sources:
--1 Lookout: Platforms with space or manning restrictions while
underway (at the forward part of a small boat or ship) and
platforms using active sonar while moored or at anchor
(including pierside).
--2 Lookouts: Platforms without space or manning restrictions
while underway (at the forward part of the ship).
Sources that are not hull-mounted:
--1 Lookout on the ship or aircraft conducting the activity.
Mitigation Requirements:
Mitigation zones:
--Refer to During the activity below.
[[Page 46373]]
Prior to the initial start of the activity (e.g., when
maneuvering on station):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of active sonar transmission.
During the activity:
--Low-frequency active sonar at or above 200 dB or more, and
hull-mounted mid-frequency active sonar: Navy personnel must
observe the mitigation zone for marine mammals; Navy personnel
will power down active sonar transmission by 6 dB if marine
mammals are observed within 1,000 yd of the sonar source; Navy
personnel will power down an additional 4 dB (for a total of 10
dB total) within 500 yd; Navy personnel must cease transmission
within 200 yd of the sonar source.
--Low-frequency active sonar below 200 dB, mid-frequency active
sonar sources that are not hull-mounted, and high-frequency
active sonar: Navy personnel must observe the mitigation zone
for marine mammals; Navy personnel will cease active sonar
transmission if observed within 200 yd of the sonar source.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
or powering up active sonar transmission) until one of the
following conditions has been met: (1) The animal is observed
exiting the mitigation zone; (2) the animal is thought to have
exited the mitigation zone based on a determination of its
course, speed, and movement relative to the sonar source; (3)
the mitigation zone has been clear from any additional
sightings for 10 min. for aircraft-deployed sonar sources or 30
min for vessel-deployed sonar sources; (4) for mobile
activities, the active sonar source has transited a distance
equal to double that of the mitigation zone size beyond the
location of the last sighting; or (5) for activities using hull-
mounted sonar, the ship concludes that dolphins are
deliberately closing in on the ship to ride the ship's bow
wave, and are therefore out of the main transmission axis of
the sonar (and there are no other marine mammal sightings
within the mitigation zone).
------------------------------------------------------------------------
Table 31--Procedural Mitigation for Weapons Firing Noise
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Weapons firing noise associated with large-caliber gunnery
activities.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the ship conducting the firing.
Depending on the activity, the Lookout could be the same as
the one described in Procedural Mitigation for Explosive Medium-
and Large-Caliber Projectiles (Table 34) or Procedural Mitigation
for Small-, Medium-, and Large-Caliber Non-Explosive Practice
Munitions (Table 43).
Mitigation Requirements:
Mitigation Zone:
--30[deg] on either side of the firing line out to 70 yd from
the muzzle of the weapon being fired.
Prior to the initial start of the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if observed, Navy personnel will relocate or delay the
start of weapons firing.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease weapons firing.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
weapons firing) until one of the following conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the firing ship; (3) the mitigation zone has been
clear from any additional sightings for 30 min; or (4) for
mobile activities, the firing ship has transited a distance
equal to double that of the mitigation zone size beyond the
location of the last sighting.
------------------------------------------------------------------------
Table 32--Procedural Mitigation for Explosive Sonobuoys
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive sonobuoys.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft or on a small boat.
If additional platforms are participating in the activity,
Navy personnel positioned in those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation Zone:
--600 yd around an explosive sonobuoy.
Prior to the initial start of the activity (e.g., during
deployment of a sonobuoy pattern, which typically lasts 20-30
minutes):
--Navy personnel will conduct passive acoustic monitoring for
marine mammals; Navy personnel will use information from
detections to assist visual observations.
--Navy personnel will visually observe the mitigation zone for
marine mammals; if marine mammals are observed, Navy personnel
will relocate or delay the start of sonobuoy or source/receiver
pair detonations.
During the activity:
[[Page 46374]]
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, cease sonobuoy or
source/receiver pair detonations.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
detonations) until one of the following conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the sonobuoy; or (3) the mitigation zone has been
clear from any additional sightings for 10 min when the
activity involves aircraft that have fuel constraints, or 30
min when the activity involves aircraft that are not typically
fuel constrained.
After completion of the activity (e.g., prior to
maneuvering off station):
--When practical (e.g., when platforms are not constrained by
fuel restrictions or mission-essential follow-on commitments),
Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 33--Procedural Mitigation for Explosive Torpedoes
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive Torpedoes.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation Zone:
--2,100 yd around the intended impact location.
Prior to the initial start of the activity (e.g., during
deployment of the target):
--Navy personnel will conduct passive acoustic monitoring for
marine mammals; Navy personnel will use information from
detections to assist visual observations.
--Navy personnel will visually observe the mitigation zone for
marine mammals; if marine mammals are observed, Navy personnel
will relocate or delay the start of firing.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease firing.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
firing) until one of the following conditions has been met: (1)
The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the intended impact location; or (3) the mitigation zone has
been clear from any additional sightings for 10 min when the
activity involves aircraft that have fuel constraints, or 30
min when the activity involves aircraft that are not typically
fuel constrained.
After completion of the activity (e.g., prior to
maneuvering off station):
--When practical (e.g., when platforms are not constrained by
fuel restrictions or mission-essential follow-on commitments),
Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 34--Procedural Mitigation for Explosive Medium-Caliber and Large-
Caliber Projectiles
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Gunnery activities using explosive medium-caliber and large-
caliber projectiles.
--Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout on the vessel or aircraft conducting the
activity.
--For activities using explosive large-caliber projectiles,
depending on the activity, the Lookout could be the same as the
one described in Weapons Firing Noise (Table 31).
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation zones:
--200 yd around the intended impact location for air-to-surface
activities using explosive medium-caliber projectiles.
--600 yd around the intended impact location for surface-to-
surface activities using explosive medium-caliber projectiles.
[[Page 46375]]
--1,000 yd around the intended impact location for surface-to-
surface activities using explosive large-caliber projectiles.
Prior to the initial start of the activity (e.g., when
maneuvering on station):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of firing.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease firing.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
firing) until one of the following conditions has been met: (1)
The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the intended impact location; (3) the mitigation zone has been
clear from any additional sightings for 10 min for aircraft-
based firing or 30 min for vessel-based firing; or (4) for
activities using mobile targets, the intended impact location
has transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting.
After completion of the activity (e.g., prior to
maneuvering off station):
--When practical (e.g., when platforms are not constrained by
fuel restrictions or mission-essential follow-on commitments),
Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 35--Procedural Mitigation for Explosive Missiles and Rockets
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Aircraft-deployed explosive missiles and rockets.
--Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation zones:
--900 yd around the intended impact location for missiles or
rockets with 0.6-20 lb net explosive weight.
--2,000 yd around the intended impact location for missiles with
21-500 lb net explosive weight.
Prior to the initial start of the activity (e.g., during a
fly-over of the mitigation zone):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of firing.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease firing.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
firing) until one of the following conditions has been met: (1)
The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the intended impact location; or (3) the mitigation zone has
been clear from any additional sightings for 10 min when the
activity involves aircraft that have fuel constraints, or 30
min when the activity involves aircraft that are not typically
fuel constrained.
After completion of the activity (e.g., prior to
maneuvering off station):
--When practical (e.g., when platforms are not constrained by
fuel restrictions or mission-essential follow-on commitments),
Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 36--Procedural Mitigation for Explosive Bombs
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive bombs.
Number of Lookouts and Observation Platform:
1 Lookout positioned in the aircraft conducting the
activity.
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation zone:
[[Page 46376]]
--2,500 yd around the intended target.
Prior to the initial start of the activity (e.g., when
arriving on station):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of bomb deployment.
During the activity (e.g., during target approach):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease bomb deployment.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
bomb deployment) until one of the following conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the intended target; (3) the mitigation zone has
been clear from any additional sightings for 10 min; or (4) for
activities using mobile targets, the intended target has
transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting.
After completion of the activity (e.g., prior to
maneuvering off station):
--When practical (e.g., when platforms are not constrained by
fuel restrictions or mission-essential follow-on commitments),
Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 37--Procedural Mitigation for Sinking Exercises
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Sinking exercises.
Number of Lookouts and Observation Platform:
2 Lookouts (one positioned in an aircraft and one on a
vessel).
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation Zone:
--2.5 nmi around the target ship hulk.
Prior to the initial start of the activity (90 min prior to
the first firing):
--Navy personnel will conduct aerial observations of the
mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel will delay the start of firing.
During the activity:
--Navy personnel will conduct passive acoustic monitoring for
marine mammals; Navy personnel will use information from
detections to assist visual observations.
--Navy personnel will visually observe the mitigation zone for
marine mammals from the vessel; if marine mammals are observed,
Navy personnel must cease firing.
--Immediately after any planned or unplanned breaks in weapons
firing of longer than 2 hours, Navy personnel will observe the
mitigation zone for marine mammals from the aircraft and
vessel; if marine mammals are observed, Navy personnel must
delay recommencement of firing.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
firing) until one of the following conditions has been met: (1)
The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the target ship hulk; or (3) the mitigation zone has been clear
from any additional sightings for 30 min.
After completion of the activity (for 2 hours after sinking
the vessel or until sunset, whichever comes first):
--Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 38--Procedural Mitigation for Explosive Mine Countermeasure and
Neutralization Activities
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive mine countermeasure and neutralization
activities.
Number of Lookouts and Observation Platform:
1 Lookout positioned on a vessel or in an aircraft.
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
[[Page 46377]]
Mitigation Zone:
--600 yd around the detonation site.
Prior to the initial start of the activity (e.g., when
maneuvering on station; typically, 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel
constrained):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of detonations.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease detonations.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
detonations) until one of the following conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to detonation site; or (3) the mitigation zone has
been clear from any additional sightings for 10 min when the
activity involves aircraft that have fuel constraints, or 30
min. when the activity involves aircraft that are not typically
fuel constrained.
After completion of the activity (typically 10 min when the
activity involves aircraft that have fuel constraints, or 30 min
when the activity involves aircraft that are not typically fuel
constrained):
--Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 39--Procedural Mitigation for Explosive Mine Neutralization
Activities Involving Navy Divers
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive mine neutralization activities involving Navy
divers.
Number of Lookouts and Observation Platforms:
2 Lookouts (two small boats with one Lookout each, or one
Lookout on a small boat and one in a rotary-wing aircraft) when
implementing the smaller mitigation zone.
4 Lookouts (two small boats with two Lookouts each), and a
pilot or member of an aircrew will serve as an additional Lookout
if aircraft are used during the activity, when implementing the
larger mitigation zone.
All divers placing the charges on mines will support the
Lookouts while performing their regular duties and will report
applicable sightings to their supporting small boat or Range Safety
Officer.
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation Zones:
--For Lookouts on small boats or aircraft: 500 yd around the
detonation site during activities under positive control.
--For Lookouts on small boats or aircraft: 1,000 yd around the
detonation site during activities using time-delay fuses.
--For divers: The underwater detonation location, which is
defined as the sea space within the divers' range of visibility
but no further than the mitigation zone specified for Lookouts
on small boats or aircraft (500 yd or 1,000 yd depending on the
charge type).
Prior to the initial start of the activity (when
maneuvering on station for activities under positive control; 30
min for activities using time-delay firing devices):
--Lookouts on small boats or aircraft will observe the
mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel will relocate or delay the start of
detonations or fuse initiation.
During the activity:
--Lookouts on small boats or aircraft will observe the
mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel will cease detonations or fuse
initiation.
--While performing their normal duties, during the activity.
divers will observe the underwater detonation location for
marine mammals. Divers will notify their supporting small boat
or Range Safety Officer of marine mammal sightings at the
underwater detonation location; if observed, Navy personnel
will cease detonations or fuse initiation.
--To the maximum extent practical depending on mission
requirements, safety, and environmental conditions, boats will
position themselves near the mid-point of the mitigation zone
radius (but outside of the detonation plume and human safety
zone), will position themselves on opposite sides of the
detonation location (when two boats are used), and will travel
in a circular pattern around the detonation location with one
Lookout observing inward toward the detonation site and the
other observing outward toward the perimeter of the mitigation
zone.
--If used, aircraft will travel in a circular pattern around the
detonation location to the maximum extent practicable.
--Navy personnel will not set time-delay firing devices to
exceed 10 min.
Commencement/recommencement conditions after a marine
mammal before or during the activity:
[[Page 46378]]
--Navy personnel will allow a sighted marine mammal to leave the
underwater detonation location or mitigation zone (as
applicable) prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
detonations or fuse initiation) until one of the following
conditions has been met: (1) The animal is observed exiting the
500 yd or 1,000 yd mitigation zone; (2) the animal is thought
to have exited the 500 yd or 1,000 yd mitigation zone based on
a determination of its course, speed, and movement relative to
the detonation site; or (3) the 500 yd or 1,000 yd mitigation
zone ((for Lookouts on small boats or aircraft) and the
underwater detonation location (for divers)) has been clear
from any additional sightings for 10 min during activities
under positive control with aircraft that have fuel
constraints, or 30 min during activities under positive control
with aircraft that are not typically fuel constrained and
during activities using time-delay firing devices.
After completion of an activity (for 30 min):
--Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 40--Procedural Mitigation for Maritime Security Operations--Anti-
Swimmer Grenades
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Maritime Security Operations--Anti-Swimmer Grenades.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the small boat conducting the
activity.
If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) will support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
Mitigation Requirements:
Mitigation zone:
--200 yd around the intended detonation location.
Prior to the initial start of the activity (e.g., when
maneuvering on station):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of detonations.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease detonations.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
detonations) until one of the following conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the intended detonation location; (3) the
mitigation zone has been clear from any additional sightings
for 30 min; or (4) the intended detonation location has
transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting.
After completion of the activity (e.g., prior to
maneuvering off station):
--When practical (e.g., when platforms are not constrained by
fuel restrictions or mission-essential follow-on commitments),
Navy personnel will observe the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed,
Navy personnel will follow established incident reporting
procedures.
--If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel positioned on these
assets will assist in the visual observation of the area where
detonations occurred.
------------------------------------------------------------------------
Table 41--Procedural Mitigation for Vessel Movement
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Vessel movement:
--The mitigation will not be applied if (1) the vessel's safety
is threatened, (2) the vessel is restricted in its ability to
maneuver (e.g., during launching and recovery of aircraft or
landing craft, during towing activities, when mooring, etc.),
(3) the vessel is submerged or operated autonomously, or (4)
when impractical based on mission requirements (e.g., during
Amphibious Assault and Amphibious Raid exercises).
Number of Lookouts and Observation Platform:
1 Lookout on the vessel that is underway.
Mitigation Requirements:
Mitigation Zones:
--500 yd around whales.
--200 yd around other marine mammals (except bow-riding
dolphins).
During the activity:
--When underway, Navy personnel will observe the mitigation zone
for marine mammals; if marine mammals are observed, Navy
personnel will maneuver to maintain distance.
[[Page 46379]]
Additional requirements:
--If a marine mammal vessel strike occurs, Navy personnel will
follow the established incident reporting procedures.
------------------------------------------------------------------------
Table 42--Procedural Mitigation for Towed In-Water Devices
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Towed in-water devices:
--Mitigation applies to devices that are towed from a manned
surface platform or manned aircraft.
--The mitigation will not be applied if the safety of the towing
platform or in-water device is threatened.
Number of Lookouts and Observation Platform:
1 Lookout positioned on a manned towing platform.
Mitigation Requirements:
Mitigation Zones:
--250 yd. around marine mammals.
During the activity (i.e., when towing an in-water device):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
maneuver to maintain distance.
------------------------------------------------------------------------
Table 43--Procedural Mitigation for Small-, Medium-, and Large-Caliber
Non-Explosive Practice Munitions
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Gunnery activities using small-, medium-, and large-caliber
non-explosive practice munitions.
--Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the platform conducting the
activity.
Depending on the activity, the Lookout could be the same as
the one described in Procedural Mitigation for Weapons Firing Noise
(Table 31).
Mitigation Requirements:
Mitigation Zone:
--200 yd around the intended impact location.
Prior to the initial start of the activity (e.g., when
maneuvering on station):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of firing.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease firing.
Commencement/recommencement conditions after a marine
mammal sighting before or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
firing) until one of the following conditions has been met: (1)
The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the intended impact location; (3) the mitigation zone has been
clear from any additional sightings for 10 min for aircraft-
based firing or 30 min for vessel-based firing; or (4) for
activities using a mobile target, the intended impact location
has transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting.
------------------------------------------------------------------------
Table 44--Procedural Mitigation for Non-Explosive Missiles and Rockets
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Aircraft-deployed non-explosive missiles and rockets.
Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
Mitigation Requirements:
Mitigation Zone:
--900 yd around the intended impact location.
Prior to the initial start of the activity (e.g., during a
fly-over of the mitigation zone):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of firing.
During the activity:
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease firing.
Commencement/recommencement conditions after a marine
mammal sighting prior to or during the activity:
[[Page 46380]]
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
firing) until one of the following conditions has been met: (1)
The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the intended impact location; or (3) the mitigation zone has
been clear from any additional sightings for 10 min when the
activity involves aircraft that have fuel constraints, or 30
min when the activity involves aircraft that are not typically
fuel constrained.
------------------------------------------------------------------------
Table 45--Procedural Mitigation for Non-Explosive Bombs and Mine Shapes
------------------------------------------------------------------------
Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
Non-explosive bombs.
Non-explosive mine shapes during mine laying activities.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
Mitigation Requirements:
Mitigation Zone:
--1,000 yd around the intended target.
Prior to the initial start of the activity (e.g., when
arriving on station):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
relocate or delay the start of bomb deployment or mine laying.
During the activity (e.g., during approach of the target or
intended minefield location):
--Navy personnel will observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel will
cease bomb deployment or mine laying.
Commencement/recommencement conditions after a marine
mammal sighting prior to or during the activity:
--Navy personnel will allow a sighted marine mammal to leave the
mitigation zone prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing
bomb deployment or mine laying) until one of the following
conditions has been met: (1) The animal is observed exiting the
mitigation zone; (2) the animal is thought to have exited the
mitigation zone based on a determination of its course, speed,
and movement relative to the intended target or minefield
location; (3) the mitigation zone has been clear from any
additional sightings for 10 min; or (4) for activities using
mobile targets, the intended target has transited a distance
equal to double that of the mitigation zone size beyond the
location of the last sighting.
------------------------------------------------------------------------
Mitigation Areas
In addition to procedural mitigation, the Navy will implement
mitigation measures within mitigation areas to avoid or minimize
potential impacts on marine mammals. A full technical analysis (for
which the methods were discussed above) of the mitigation areas that
the Navy considered for marine mammals is provided in Appendix I
(Geographic Mitigation Assessment) of the 2020 MITT FSEIS/OEIS. NMFS
and the Navy took into account public comments received on the 2019
MITT DSEIS/OEIS and the 2019 MITT proposed rule, best available
science, and the practicability of implementing additional mitigation
measures and has enhanced the mitigation areas and mitigation measures,
beyond the 2015-2020 regulations, to further reduce impacts to marine
mammals.
Information on the mitigation measures that the Navy will implement
within mitigation areas is provided in Table 46 (see below). The
mitigation applies year-round unless specified otherwise in the table.
NMFS conducted an independent analysis of the mitigation areas that
the Navy will implement and that are included in this rule, which are
described below, in Table 46. NMFS' analysis indicates that the
measures in these mitigation areas will reduce the likelihood or
severity of adverse impacts to marine mammal species or their habitat
in the manner described in this rule and are practicable for the Navy.
NMFS is heavily reliant on the Navy's description of operational
practicability, since the Navy is best equipped to describe the degree
to which a given mitigation measure affects personnel safety or mission
effectiveness, and is practical to implement. The Navy considers the
measures in this rule to be practicable, and NMFS concurs. We further
discuss the manner in which the Geographic Mitigation Areas in the rule
will reduce the likelihood or severity of adverse impacts to marine
mammal species or their habitat below.
Table 46--Geographic Mitigation Areas for Marine Mammals in the MITT
Study Area
------------------------------------------------------------------------
Mitigation Area Description
-------------------------------------------------------------------------
Stressor or Activity:
Sonar.
In-water Explosives.
Mitigation Requirements:
Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
Areas (Figures 1 and 2):
--Navy personnel will conduct a maximum annual total of 20 hours
of surface ship hull-mounted MF1 mid-frequency active sonar
from December 1 through April 30 within the Marpi Reef and
Chalan Kanoa Reef Geographic Mitigation Areas combined (20
hours total for both areas).
--Navy personnel will report the total hours of active sonar
(all bins, by bin) used in the Marpi Reef and Chalan Kanoa Reef
Geographic Mitigation Areas from December 1 through April 30 in
the annual training and testing exercise report submitted to
NMFS.
--Navy personnel will not use in-water explosives in the Marpi
Reef and Chalan Kanoa Reef Geographic Mitigation Areas year-
round.
[[Page 46381]]
--Navy personnel will issue an annual seasonal awareness
notification message to alert Navy ships and aircraft operating
in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
Areas to the possible presence of increased concentrations of
humpback whales from December 1 through April 30. To maintain
safety of navigation and to avoid interactions with large
whales during transits, Navy personnel will instruct vessels to
remain vigilant to the presence of humpback whales, that when
concentrated seasonally, may become vulnerable to vessel
strikes. Navy personnel will use the information from the
awareness notification messages to assist their visual
observation of applicable mitigation zones during training and
testing activities and to aid in the implementation of
procedural mitigation.
--Should national security present a requirement to conduct
training or testing prohibited by the mitigation requirements
specified in this table, Navy personnel will obtain permission
from the appropriate designated Command authority prior to
commencement of the activity. Navy personnel will provide NMFS
with advance notification and include relevant information
(e.g., sonar hours, explosives use) in its annual activity
reports submitted to NMFS.
Agat Bay Nearshore Geographic Mitigation Area (Figure 3):
--Navy personnel will not use surface ship hull-mounted MF1 mid-
frequency active sonar in the Agat Bay Nearshore Geographic
Mitigation Area year-round.
--Navy personnel will not use in-water explosives in the Agat
Bay Nearshore Mitigation Area year-round.
--Should national security require the use of MF1 surface ship
hull-mounted mid-frequency active sonar or explosives
prohibited by the mitigation requirements, Navy personnel will
obtain permission from the appropriate designated Command
authority prior to commencement of the activity. Navy personnel
will provide NMFS with advance notification and include
relevant information (e.g., sonar hours, explosives use) in the
annual activity reports submitted to NMFS.
------------------------------------------------------------------------
Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas
The proposed rule included a restriction on the use of explosives
in these two mitigation areas, but no limitation on the use of active
sonar. The final rule includes a 20-hour annual cap from December 1
through April 30 on the use of hull-mounted MF1 mid-frequency active
sonar during training and testing activities within the Marpi Reef and
Chalan Kanoa Reef Geographic Mitigation Areas (20 hours for both areas
combined). In addition to the reporting of the total hours of surface
ship hull-mounted MF1 mid-frequency active sonar, the Navy will now
also report all sonar sources used (all bins, by bin) within the Chalan
Kanoa and Marpi Reef Geographic Mitigation Areas from December 1 to
April 30 in the annual MITT classified Exercise Reports. This will
provide NMFS with more specific data in order to evaluate sonar use
with current mitigation measures in the geographic mitigation areas and
to determine if any changes are needed through Adaptive Management.
While the shallower water within the Chalan Kanoa Reef and Marpi
Reef Geographic Mitigation Areas has not been a high-use area for Navy
MTEs and ASW training events as the area is considered generally less
suitable (Navy training is more typically conducted beyond 3 nmi from
shore and in waters greater than 200-m depth, with MTEs typically far
offshore), the Navy has stressed the broader need for flexibility as
well as the specific need not to restrict training areas entirely in
this part of the MITT Study Area given the proximity to forward
deployed operations (i.e., U.S. 7th fleet's continuous presence in the
Indo-Pacific region, which is a National Defense Strategy priority
theater of operation) and the need to have the option to conduct
training quickly and to respond to emergent national security threats.
Following extensive discussions with the Navy through which more
specific information about the Navy's likely activity in the Chalan
Kanoa Reef and Marpi Reef Geographic Mitigation Areas was provided, new
information about humpback whale occurrence in the two Geographic
Mitigation Areas emerged, and new analyses were conducted (see the
Estimated Take of Marine Mammals section). NMFS has included a
requirement for the Navy to implement the annual 20-hr cap from
December 1 through April 30 on hull-mounted MF1 MFAS within the two
Geographic Mitigation Areas to minimize sonar exposure and reduce take
by Level B harassment of humpback whales in this important reproductive
area.
To determine the extent of the Marpi Reef and Chalan Kanoa Reef
Geographic Mitigation Areas, the Navy obtained all humpback whale
sighting data from 2015-2019 in the Marianas from NMFS' PIFSC (Figures
1 and 2). As described in the Description of Marine Mammals and Their
Habitat in the Area of the Specified Activities section of the rule,
humpback whales, including mother-calf pairs, have been seasonally
present in shallow waters (out to the 400-m isobath) and the science
indicates the areas may be of biological importance to humpback whales
for biologically important life processes associated with reproduction
(e.g., breeding, birthing, and nursing) during the winter months,
generally December through April.
Calves are considered more sensitive and susceptible to adverse
impacts from Navy stressors than adults (especially given their lesser
weight and the association between weight and explosive impacts), as
well as being especially reliant upon mother-calf communication for
protection and guidance. Both gestation and lactation increase energy
demands for mothers. Breeding activities typically involve
vocalizations and complex social interactions that can include violent
interactions between males. Reducing exposure of humpback whales to
explosive detonations and sonar use in the Marpi Reef and Chalan Kanoa
Reef Geographic Mitigation Areas during the months of December through
April is expected to reduce the likelihood of impacts that could affect
reproduction or survival of individual animals, by minimizing impacts
on calves during this sensitive life stage, avoiding or minimizing the
additional energetic costs to mothers of avoiding or leaving the area
during explosives exercises and sonar use, and minimizing the chances
that important breeding behaviors are interrupted to the point that
reproduction is inhibited or abandoned for the year, or otherwise
interfered with.
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[[Page 46383]]
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[[Page 46384]]
Agat Bay Nearshore Geographic Mitigation Area
The Agat Bay Nearshore Geographic Mitigation Area encompasses the
shoreline between Tipalao, Dadi Beach, and Agat on the west coast of
Guam, with a boundary across the bay enclosing an area of approximately
5 km\2\ in relatively shallow waters (less than 100 m). The boundaries
of the Agat Bay Nearshore Geographic Mitigation Area (Figure 3) were
defined by Navy scientists based on spinner dolphin sightings
documented during small boat surveys from 2010 through 2014. Spinner
dolphins have been the most frequently encountered species during small
boat reconnaissance surveys conducted in the Mariana Islands since
2010. Consistent with more intensive studies completed for the species
in the Hawaiian Islands, island-associated spinner dolphins are
expected to occur in shallow water resting areas (about 50 m deep or
less) in the morning and throughout the middle of the day, moving into
deep waters offshore during the night to feed (Heenehan et al., 2016b;
Heenehan et al., 2017a; Hill et al., 2010; Norris and Dohl, 1980). The
best available science, as described above, indicates that Agat Bay is
important resting habitat for spinner dolphins.
Behavioral disruptions during resting periods can adversely impact
health and energetic budgets by not allowing spinner dolphins to get
the needed rest and/or by creating the need to travel and expend
additional energy to find other suitable resting areas. Avoiding sonar
and explosives in this geographic mitigation area year-round reduces
the likelihood of energetic impacts that could accrue and affect
reproduction or survival of these individuals.
[[Page 46385]]
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Mitigation Conclusions
NMFS has carefully evaluated the Navy's mitigation measures--many
of which were developed with NMFS' input during the previous phases of
Navy training and testing authorizations but several of which are new
since implementation of the 2015 to 2020 regulations--and considered a
broad range of other measures (i.e., the measures considered but
eliminated in the 2020 MITT FSEIS/OEIS, which reflect many of the
comments that have arisen via NMFS or public input in past years) in
the context of ensuring that NMFS prescribes the means of effecting the
least practicable adverse impact on the affected marine mammal species
and their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: The
manner in which, and the degree to which, the successful implementation
of the mitigation measures is expected to reduce the likelihood and/or
magnitude of adverse impacts to marine mammal species and their
habitat; the proven or likely efficacy of the measures; and the
practicability of the measures for applicant implementation, including
consideration of personnel safety, practicality of implementation, and
[[Page 46386]]
impact on the effectiveness of the military readiness activity.
Based on our evaluation of the Navy's measures, as well as other
measures considered by the Navy and NMFS, NMFS has determined that the
mitigation measures included in this final rule are the appropriate
means of effecting the least practicable adverse impact on the marine
mammal species and their habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and
considering specifically personnel safety, practicality of
implementation, and impact on the effectiveness of the military
readiness activity. Additionally, an adaptive management provision
ensures that mitigation is regularly assessed and provides a mechanism
to improve the mitigation, based on the factors above, through
modification as appropriate. Thus, NMFS concludes that the mitigation
measures outlined in this final rule satisfy the statutory standard and
that any adverse impacts that remain cannot practicably be further
mitigated.
Monitoring
Section 101(a)(5)(A) of the MMPA states that in order to authorize
incidental take for an activity, NMFS must set forth requirements
pertaining to the monitoring and reporting of such taking. The MMPA
implementing regulations at 50 CFR 216.104(a)(13) indicate that
requests for incidental take authorizations must include the suggested
means of accomplishing the necessary monitoring and reporting that will
result in increased knowledge of the species and of the level of taking
or impacts on populations of marine mammals that are expected to be
present.
Although the Navy has been conducting research and monitoring in
the MITT Study Area for over 20 years, it developed a formal marine
species monitoring program in support of the MMPA and ESA
authorizations in 2009. This robust program has resulted in hundreds of
technical reports and publications on marine mammals that have informed
Navy and NMFS analyses in environmental planning documents, rules, and
ESA Biological Opinions. The reports are made available to the public
on the Navy's marine species monitoring website
(www.navymarinespeciesmonitoring.us) and the data on the Ocean
Biogeographic Information System Spatial Ecological Analysis of
Megavertebrate Populations (OBIS-SEAMAP) (http://seamap.env.duke .edu/
).
The Navy will continue collecting monitoring data to inform our
understanding of the occurrence of marine mammals in the MITT Study
Area; the likely exposure of marine mammals to stressors of concern in
the MITT Study Area; the response of marine mammals to exposures to
stressors; the consequences of a particular marine mammal response to
their individual fitness and, ultimately, populations; and the
effectiveness of implemented mitigation measures. Taken together,
mitigation and monitoring comprise the Navy's integrated approach for
reducing environmental impacts from the specified activities. The
Navy's overall monitoring approach seeks to leverage and build on
existing research efforts whenever possible.
As agreed upon between the Navy and NMFS, the monitoring measures
presented here, as well as the mitigation measures described above,
focus on the protection and management of potentially affected marine
mammals. A well-designed monitoring program can provide important
feedback for validating assumptions made in analyses and allow for
adaptive management of marine resources. Monitoring is required under
the MMPA, and details of the monitoring program for the specified
activities have been developed through coordination between NMFS and
the Navy through the regulatory process for previous Navy at-sea
training and testing activities.
Integrated Comprehensive Monitoring Program (ICMP)
The Navy's ICMP is intended to coordinate marine species monitoring
efforts across all regions and to allocate the most appropriate level
and type of effort for each range complex based on a set of
standardized objectives, and in acknowledgement of regional expertise
and resource availability. The ICMP is designed to be flexible,
scalable, and adaptable through the adaptive management and strategic
planning processes to periodically assess progress and reevaluate
objectives. This process includes conducting an annual adaptive
management review meeting, at which the Navy and NMFS jointly consider
the prior-year goals, monitoring results, and related scientific
advances to determine if monitoring plan modifications are warranted to
more effectively address program goals. Although the ICMP does not
specify actual monitoring field work or individual projects, it does
establish a matrix of goals and objectives that have been developed in
coordination with NMFS. As the ICMP is implemented through the
Strategic Planning Process, detailed and specific studies are developed
which support the Navy's and NMFS' top-level monitoring goals. In
essence, the ICMP directs that monitoring activities relating to the
effects of Navy training and testing activities on marine species
should be designed to contribute towards one or more of the following
top-level goals:
An increase in our understanding of the likely occurrence
of marine mammals and/or ESA-listed marine species in the vicinity of
the action (i.e., presence, abundance, distribution, and/or density of
species);
An increase in our understanding of the nature, scope, or
context of the likely exposure of marine mammals and/or ESA-listed
species to any of the potential stressor(s) associated with the action
(e.g., sound, explosive detonation, or military expended materials)
through better understanding of the following: (1) The action and the
environment in which it occurs (e.g., sound source characterization,
propagation, and ambient noise levels); (2) the affected species (e.g.,
life history or dive patterns); (3) the likely co-occurrence of marine
mammals and/or ESA-listed marine species with the action (in whole or
part); and/or (4) the likely biological or behavioral context of
exposure to the stressor for the marine mammal and/or ESA-listed marine
species (e.g., age class of exposed animals or known pupping, calving
or feeding areas);
An increase in our understanding of how individual marine
mammals or ESA-listed marine species respond (behaviorally or
physiologically) to the specific stressors associated with the action
(in specific contexts, where possible, e.g., at what distance or
received level);
An increase in our understanding of how anticipated
individual responses, to individual stressors or anticipated
combinations of stressors, may impact either: (1) The long-term fitness
and survival of an individual or (2) the population, species, or stock
(e.g., through effects on annual rates of recruitment or survival);
An increase in our understanding of the effectiveness of
mitigation and monitoring measures;
A better understanding and record of the manner in which
the Navy complies with the incidental take regulations and LOAs and the
ESA Incidental Take Statement;
An increase in the probability of detecting marine mammals
(through improved technology or methods), both specifically within the
mitigation zone (thus allowing for more effective
[[Page 46387]]
implementation of the mitigation) and in general, to better achieve the
above goals; and
Ensuring that adverse impact of activities remains at the
least practicable level.
Strategic Planning Process for Marine Species Monitoring
The Navy also developed the Strategic Planning Process for Marine
Species Monitoring, which establishes the guidelines and processes
necessary to develop, evaluate, and fund individual projects based on
objective scientific study questions. The process uses an underlying
framework designed around intermediate scientific objectives and a
conceptual framework incorporating a progression of knowledge spanning
occurrence, exposure, response, and consequence. The Strategic Planning
Process for Marine Species Monitoring is used to set overarching
intermediate scientific objectives; develop individual monitoring
project concepts; identify potential species of interest at a regional
scale; evaluate, prioritize and select specific monitoring projects to
fund or continue supporting for a given fiscal year; execute and manage
selected monitoring projects; and report and evaluate progress and
results. This process addresses relative investments to different range
complexes based on goals across all range complexes, and monitoring
will leverage multiple techniques for data acquisition and analysis
whenever possible. The Strategic Planning Process for Marine Species
Monitoring is also available online (http://www.navymarinespeciesmonitoring.us/).
Past and Current Monitoring in the MITT Study Area
The monitoring program has undergone significant changes since the
first rule was issued for the MITT Study Area in 2009, which highlights
the monitoring program's evolution through the process of adaptive
management. The monitoring program developed for the first cycle of
environmental compliance documents (e.g., U.S. Department of the Navy,
2008) utilized effort-based compliance metrics that were somewhat
limiting. Through adaptive management discussions, the Navy designed
and conducted monitoring studies according to scientific objectives,
thereby eliminating basing requirements upon metrics of level-of-
effort. Furthermore, refinements of scientific objective have continued
through the latest authorization cycle.
Progress has also been made on the conceptual framework categories
from the Scientific Advisory Group for Navy Marine Species Monitoring
(U.S. Department of the Navy, 2011c), ranging from occurrence of
animals, to their exposure, response, and population consequences. The
Navy continues to manage the Atlantic and Pacific program as a whole,
with monitoring in each range complex taking a slightly different but
complementary approach. The Navy has continued to use the approach of
layering multiple simultaneous components in many of the range
complexes to leverage an increase in return of the progress toward
answering scientific monitoring questions. This includes, in the
Marianas for example, (a) glider deployment in offshore areas, (b)
analysis of existing passive acoustic monitoring datasets, (c) small
boat surveys using visual, biopsy, and satellite tagging and (d)
seasonal, humpback whale specific surveys.
Specific monitoring under the 2015-2020 regulations includes:
[ssquf] Review of the available data and analyses in the MITT Study
Area 2010 through February 2018 (2019a).
[ssquf] The continuation of annual small vessel nearshore surveys,
sightings, satellite tagging, biopsy and genetic analysis, photo-
identification, and opportunistic acoustic recording off Guam, Saipan,
Tinian, Rota, and Aguigan in partnership with NMFS (Hill et al., 2015;
Hill et al., 2016b; Hill et al., 2017a; Hill et al., 2018, Hill et al.,
2019b). The satellite tagging and genetic analyses have resulted in the
first information discovered on the movement patterns, habitat
preference, and population structure of multiple odontocete species in
the MITT Study Area.
[ssquf] Since 2015, the addition of a series of small vessel
surveys in the winter season dedicated to humpback whales has provided
new information relating to the occurrence, calving behavior, and
population identity of this species (Hill et al., 2016a; Hill et al.,
2017b), which had not previously been sighted during the small vessel
surveys in the summer or winter. This work has included sighting data,
photo ID matches of individuals to other areas demonstrating migration
as well as re-sights within the Marianas across different years, and
the collection of biopsy samples for genetic analyses of populations.
[ssquf] The continued deployment of passive acoustic monitoring
devices and analysis of acoustic data obtained using bottom-moored
acoustic recording devices deployed by NMFS has provided information on
the presence and seasonal occurrence of mysticetes, as well as the
occurrence of cryptic odontocetes typically found offshore, including
beaked whales and Kogia spp. (Hill et al., 2015; Hill et al., 2016a;
Hill et al., 2016b; Hill et al., 2017a; Munger et al., 2015; Norris et
al., 2017; Oleson et al., 2015; Yack et al., 2016).
[ssquf] Acoustic surveys using autonomous gliders were used to
characterize the occurrence of odontocetes and mysticetes in abyssal
offshore waters near Guam and CNMI, including species not seen in the
small vessel visual survey series such as killer whales and Risso's
dolphins. Analysis of collected data also provided new information on
the seasonality of baleen whales, patterns of beaked whale occurrence
and potential call variability, and identification of a new unknown
marine mammal call (Klinck et al., 2016b; Nieukirk et al., 2016).
[ssquf] Visual surveys were conducted from a shore-station at high
elevation on the north shore of Guam to document the nearshore
occurrence of marine mammals in waters where small vessel visual
surveys are challenging due to regularly high sea states (Deakos &
Richlen, 2015; Deakos et al., 2016).
[ssquf] Analysis of archive data that included marine mammal
sightings during Guam Department of Agriculture Division of Aquatic and
Wildlife Resources aerial surveys undertaken between 1963 and 2012
(Martin et al., 2016).
[ssquf] Analysis of archived acoustic towed-array data for an
assessment of the abundance and density of minke whales (Norris et al.,
2017), abundance and density of sperm whales (Yack et al., 2016), and
the characterization of sei and humpback whale vocalizations (Norris et
al., 2014).
Numerous publications, dissertations, and conference presentations
have resulted from research conducted under the Navy's marine species
monitoring program (https://www.navymarinespeciesmonitoring.us/reading-room/publications/), resulting in a significant contribution to the
body of marine mammal science. Publications on occurrence,
distribution, and density have fed the modeling input, and publications
on exposure and response have informed Navy and NMFS analyses of
behavioral response and consideration of mitigation measures.
Furthermore, collaboration between the monitoring program and the
Navy's research and development (e.g., the Office of Naval Research)
and demonstration-validation (e.g., Living Marine Resources) programs
has been strengthened, leading to research tools and products that have
already transitioned to the monitoring program. These include Marine
Mammal Monitoring on Ranges (M3R), controlled
[[Page 46388]]
exposure experiment behavioral response studies (CEE BRS), acoustic sea
glider surveys, and global positioning system-enabled satellite tags.
Recent progress has been made with better integration of monitoring
across all Navy at-sea study areas, including study areas in the
Pacific and the Atlantic Oceans, and various testing ranges.
Publications from the Living Marine Resources and the Office of Naval
Research programs have also resulted in significant contributions to
information on hearing ranges and acoustic criteria used in effects
modeling, exposure, and response, as well as developing tools to assess
biological significance (e.g., population-level consequences).
NMFS and the Navy also consider data collected during procedural
mitigations as monitoring. Data are collected by shipboard personnel on
hours spent training, hours of observation, hours of sonar, and marine
mammals observed within the mitigation zones when mitigations are
implemented. These data are provided to NMFS in both classified and
unclassified annual exercise reports, which will continue under this
rule.
NMFS has received multiple years' worth of annual exercise and
monitoring reports addressing active sonar use and explosive
detonations within the MITT Study Area and other Navy range complexes.
The data and information contained in these reports have been
considered in developing mitigation and monitoring measures for the
training and testing activities within the MITT Study Area. The Navy's
annual exercise and monitoring reports may be viewed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and http://www.navymarinespeciesmonitoring.us.
Prior to Phase I monitoring, the information on marine mammal
presence and occurrence in the MIRC was largely absent and limited to
anecdotal information from incidental sightings and stranding events
(U.S. Department of the Navy, 2005). In 2007, the Navy funded the
Mariana Islands Sea Turtle and Cetacean Survey (MISTCS) (U.S.
Department of the Navy, 2007) to proactively support the baseline data
feeding the MIRC EIS (U.S. Department of the Navy, 2010b). The MISTCS
research effort was the first systematic marine survey in these waters.
This survey provided the first empirically-based density estimates for
marine mammals (Fulling et al., 2011). In cooperation with NMFS, the
Phase I monitoring program beginning in 2010 was designed to address
basic occurrence-level questions in the MIRC, whereas monitoring the
impacts of Navy training such as exposure to mid-frequency active sonar
was planned for other Navy range complexes where marine mammal
occurrence was already better characterized.
This emphasis on studying occurrence continued through Phase I and
II monitoring in the MIRC, and combined various complementary
methodologies. Small vessel visual surveys collected occurrence
information, and began building the first individual identification
catalog for multiple species (Hill et al., 2014). During these visual
surveys, biopsies were collected for genetic analysis and satellite
tags were also applied, resulting in a progressively improving picture
of the habitat use and population structure of various species. Deep
water passive acoustic deployments, including autonomous gliders with
passive acoustic recorders, added complementary information on species
groups such as baleen whales and beaked whales that were rarely sighted
on the vessel surveys (Klinck et al., 2015; Munger et al., 2014; Munger
et al., 2015; Nieukirk et al., 2016; Norris et al., 2015). Other
methodologies were also explored to fill other gaps in waters generally
inaccessible to the small boat surveys including a shore-station to
survey waters on the windward side of Guam (Deakos et al., 2016). When
available, platforms of opportunity on large vessels were utilized for
visual survey and tagging (Oleson and Hill, 2010b).
At the close of Phase II monitoring, establishing the fundamentals
of marine mammal occurrence in the MITT Study Area had been
significantly advanced. The various visual and acoustic platforms have
encountered nearly all of the species that are expected to occur in the
MITT Study Area. The photographic catalogs have progressively grown to
the point that abundance analyses may be attempted for the most
commonly-encountered species. Beyond occurrence, questions related to
exposure to Navy training have been addressed, such as utilizing
satellite tag telemetry to evaluate overlap of habitat use with
underwater detonation training sites. Also during Phase II monitoring,
a pilot study to investigate reports of humpback whales occasionally
occurring off Saipan has proven fruitful, yielding confirmation of this
species there, photographic matches of individuals to other waters in
the Pacific Ocean, as well as genetics data that provide clues as to
the population identity of these animals (Hill et al., 2016a; Hill et
al., 2017b). Importantly, the compiled data were also used to inform
proposals for new mitigation areas for this rule and associated
consultations.
The ongoing regional species-specific study questions and results
from recent efforts are publicly available on the Navy's Monitoring
Program website. With basic occurrence information now well-
established, the primary goal of monitoring in the MITT Study Area
under this rule will be to close out these studies with final analyses.
As the collection and analysis of basic occurrence data across Navy
ranges (including MITT) is completed, the focus of monitoring across
all Navy range complexes will progressively move toward addressing the
important questions of exposure and response to mid-frequency active
sonar and other Navy training, as well as the consequences of those
exposures, where appropriate. The Navy's hydrophone-instrumented ranges
have proven to be a powerful tool towards this end and because of the
lack of such an instrumented range in the MITT Study Area, monitoring
investments are expected to begin shifting to other Navy range
complexes as the currently ongoing research efforts in the Mariana
Islands are completed. Any future monitoring results for the MITT Study
Area will continue to be published on the Navy's Monitoring Program
website, as well as discussed during annual adaptive management
meetings between NMFS and the Navy.
The Navy's marine species monitoring program typically supports
several monitoring projects in the MITT Study Area at any given time.
Additional details on the scientific objectives for each project can be
found at https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/. Projects can be either major multi-year efforts, or
one to two-year special studies. The monitoring projects going into
2020 include:
Co-fund (with NMFS' Pacific Island Fisheries Science
Center) the Pacific Marine Assessment Program for Protected Species
(PACMAPPS) Mariana Islands large vessel visual and acoustic survey in
spring-summer 2021 to help document marine mammal (including beaked
whale) occurrence, abundance, and distribution in the Mariana Islands.
This effort will include deployments of a towed array as well as
floating passive acoustic buoy;
Humpback whale visual survey at Farallon De Medinilla;
Continued coordination with NMFS' PIFSC for small boat
humpback
[[Page 46389]]
whale surveys at other Mariana Islands (e.g., Saipan);
Analysis of previously deployed passive acoustic sensors
for detection of humpback whale vocalizations at other islands (e.g.,
Pagan);
Conduct additional occurrence surveys for beaked whales
within the Mariana Islands beginning in fall 2021 or winter-spring 2022
(this allows assessment of PACMAPPs beaked whale analysis to inform
decision on deployment locations). This is a new monitoring project
since publication of the proposed rule; and
Funding to researchers with PIFSC for detailed necropsy
support for select stranded marine mammals in Hawaii and the Mariana
Islands.
Since publication of the proposed rule, the decision has been made
that the Navy will not be able to fund support for long-term satellite
tag tracking of humpback whales.
The Navy has also committed to a set of actions under the terms of
this rule specifically to assist in improving the science on beaked
whales (some of which will also benefit other species) and facilitate
potential adaptive management actions (e.g., modification of mitigation
or monitoring measures) relative to beaked whales in the MITT Study
Area:
Continue to fund additional stranding response/necropsy
analyses for the Pacific Islands region. In 2018, the Navy funded the
University of Hawaii for two years of additional necropsy support in
the MITT Study Area and Hawaii and planned another funding cycle in
Fiscal Year 2020. Complementing this, the Navy provided funding for
additional stranding data analysis for all species in the MITT Study
Area and HRC.
Fund research on a framework to improve the analysis of
single and mass stranding events, including the development of more
advanced statistical methods to better characterize the uncertainty
associated with data parameters. In addition, the Navy is exploring
whether additional funding is available for the Center for Naval
Analysis to research improvements to statistical analysis. As of July
2020, the status of this request was still pending.
Increased analysis for any future beaked whale stranding
in the Mariana Islands to include detailed Navy review of available
records of sonar use. In the previous regulations (2015-2020), reports
included time and location of a stranding. For these regulations, the
Navy will provide detailed record reviews including participating
units/commands to gain a better idea of what sonar was used and when,
For example in the previous regulations, the Navy's report would
include if active sonobuoys were deployed, but not information on
whether any active pings were transmitted.
Monitor beaked whale occurrence within select portions of
the MITT Study Area starting in 2022, so as to not duplicate efforts
from item number 1 above.
Include Cuvier's beaked whales as a priority species for
analysis under a 2020-2023 Navy research-funded program entitled Marine
Species Monitoring for Potential Consequences of Disturbance
(MSM4PCOD). MSM4PCOD will explore how Navy funded monitoring priorities
can be adjusted to provide the best scientific information supporting
Population Consequence of Disturbance analysis. The Navy (Living Marine
Resources Program) has already funded this program for Fiscal Years
2018-2022 and more information is available here https://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/Environmental/lmr/LMRFactSheet_Project43.pdf. The prioritization for beaked whales was
the result of a virtual conference in May 2020. Cuvier's beaked whales
in Southern California and Blainville's beaked whales in the Hawaii
Range Complex have among the most robust population and exposure
studies to date in the Pacific. Given likely similarities between
Cuvier's beaked whales across the Pacific, this program will help
identify the best way forward for monitoring for Cuvier's beaked whales
in the Mariana Islands.
Adaptive Management
The regulations governing the take of marine mammals incidental to
Navy training and testing activities in the MITT Study Area contain an
adaptive management component. Our understanding of the effects of Navy
training and testing activities (e.g., acoustic and explosive
stressors) on marine mammals continues to evolve, which makes the
inclusion of an adaptive management component both valuable and
necessary within the context of seven-year regulations.
The reporting requirements associated with this rule are designed
to provide NMFS with monitoring data from the previous year to allow
NMFS to consider whether any changes to existing mitigation and
monitoring requirements are appropriate. The use of adaptive management
allows NMFS to consider new information from different sources to
determine (with input from the Navy regarding practicability) on an
annual or biennial basis if mitigation or monitoring measures should be
modified (including additions or deletions). Mitigation measures could
be modified if new data suggests that such modifications will have a
reasonable likelihood of more effectively accomplishing the goals of
the mitigation and monitoring and if the measures are practicable. If
the modifications to the mitigation, monitoring, or reporting measures
are substantial, NMFS will publish a notice of the planned LOA in the
Federal Register and solicit public comment.
The following are some of the possible sources of applicable data
to be considered through the adaptive management process: (1) Results
from monitoring and exercises reports, as required by MMPA
authorizations; (2) results from specific stranding investigations; (3)
results from general marine mammal and sound research; and (4) any
information which reveals that marine mammals may have been taken in a
manner, extent, or number not authorized by these regulations or
subsequent LOA. The results from monitoring reports and other studies
may be viewed at https://www.navymarinespeciesmonitoring.us.
Beaked Whale Expert Panel
As noted in the discussion of beaked whale mortality in the
Comments and Responses section, as well as the Monitoring section
above, both NMFS and the Navy acknowledge the need for more data and
continuing discussion on the topic of beaked whales, mitigation, and
monitoring. Accordingly, as recommended by public commenters, the Navy
has agreed to fund and co-organize with NMFS an expert panel to provide
recommendations on scientific data gaps and uncertainties for further
protective measure consideration to minimize the impact of Navy
training and testing activities on beaked whales in the Mariana
Islands. Two years of additional data will be collected for beaked
whales in the MITT Study Area prior to the expert panel meeting.
Reporting
In order to issue incidental take authorization for an activity,
section 101(a)(5)(A) of the MMPA states that NMFS must set forth
requirements pertaining to the monitoring and reporting of such taking.
Effective reporting is critical both to compliance as well as ensuring
that the most value is obtained from the required monitoring. Reports
from individual monitoring events, results of analyses, publications,
and periodic progress reports for specific monitoring projects
[[Page 46390]]
will be posted to the Navy's Marine Species Monitoring web portal:
http://www.navymarinespeciesmonitoring.us.
Currently, there are several different reporting requirements
pursuant to the 2015-2020 regulations. All of these reporting
requirements will continue under this rule for the seven-year period.
Notification of Injured, Live Stranded or Dead Marine Mammals
The Navy will consult the Notification and Reporting Plan, which
sets out notification, reporting, and other requirements when injured,
live stranded, or dead marine mammals are detected. The Notification
and Reporting Plan is available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
Annual MITT Monitoring Report
The Navy will submit an annual report to NMFS of the MITT Study
Area monitoring which will be included in a Pacific-wide monitoring
report including results specific to the MITT Study Area describing the
implementation and results from the previous calendar year. Data
collection methods will be standardized across Pacific Range Complexes
including the MITT, HSTT, NWTT, and Gulf of Alaska (GOA) Study Areas to
the best extent practicable, to allow for comparison in different
geographic locations. The report must be submitted to the Director,
Office of Protected Resources, NMFS, either within three months after
the end of the calendar year, or within three months after the
conclusion of the monitoring year, to be determined by the Adaptive
Management process. NMFS will submit comments or questions on the draft
monitoring report, if any, within three months of receipt. The report
will be considered final after the Navy has addressed NMFS' comments,
or three months after the submittal of the draft if NMFS does not
provide comments on the draft report. Such a report describes progress
of knowledge made with respect to monitoring study questions across
multiple Navy ranges associated with the ICMP. Similar study questions
will be treated together so that progress on each topic is summarized
across multiple Navy ranges. The report need not include analyses and
content that does not provide direct assessment of cumulative progress
on the monitoring study question. This will allow the Navy to provide a
cohesive monitoring report covering multiple ranges (as per ICMP
goals), rather than entirely separate reports for the MITT, HSTT, NWTT,
and GOA Study Areas.
Annual MITT Training and Testing Exercise Report
Each year, the Navy will submit a preliminary report (Quick Look
Report) to NMFS detailing the status of authorized sound sources within
21 days after the anniversary of the date of issuance of the LOA. The
Navy will also submit a detailed report (MITT Annual Training and
Testing Exercise Report) to NMFS within three months after the one-year
anniversary of the date of issuance of the LOA. If desired, the Navy
may elect to consolidate the MITT Annual Training and Testing Exercise
Report with other exercise reports from other range complexes in the
Pacific Ocean for a single Pacific Exercise Report. NMFS will submit
comments or questions on the report, if any, within one month of
receipt. The report will be considered final after the Navy has
addressed NMFS' comments, or one month after submittal of the draft if
NMFS does not provide comments on the draft report. The annual report
will contain information on MTEs, Sinking Exercise (SINKEX) events, and
a summary of all sound sources used (total hours or quantity of each
bin of sonar or other non-impulsive source; total annual number of each
type of explosive exercises; and total annual expended/detonated rounds
(missiles, bombs, sonobuoys, etc.) for each explosive bin). The annual
report will also specifically include information on sound sources used
(i.e., total hours of operation of all active sonar (all bins, by bin))
used in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
Areas from December 1 to April 30. The annual report will also contain
both current year's sonar and explosive use data as well as cumulative
sonar and explosive use quantity from previous years' reports
Additionally, if there were any changes to the sound source allowance
in the reporting year, or cumulatively, the report will include a
discussion of why the change was made and include analysis to support
how the change did or did not affect the analysis in the 2020 MITT
FSEIS/OEIS and MMPA final rule. See the regulations below for more
detail on the content of the annual report.
The final annual/close-out report at the conclusion of the
authorization period (year seven) will also serve as the comprehensive
close-out report and include both the final year annual use compared to
annual authorization as well as a cumulative seven-year annual use
compared to seven-year authorization. NMFS must submit comments on the
draft close-out report, if any, within three months of receipt. The
report will be considered final after the Navy has addressed NMFS'
comments, or three months after the submittal of the draft if NMFS does
not provide comments.
Information included in the annual reports may be used to inform
future adaptive management of activities within the MITT Study Area.
Specific sub-reporting in these annual reports will include:
Sonar Exercise Notification: The Navy will submit an
electronic report to NMFS within fifteen calendar days after the
completion of any major training exercise indicating: Location of the
exercise; beginning and end dates of the exercise; and type of
exercise.
Other Reporting and Coordination
The Navy will continue to report and coordinate with NMFS for the
following:
Annual marine species monitoring technical review meetings
that also include researchers and the Marine Mammal Commission
(currently, every two years a joint Pacific-Atlantic meeting is held);
and
Annual Adaptive Management meetings that also include the
Marine Mammal Commission (recently modified to occur in conjunction
with the annual monitoring technical review meeting).
Analysis and Negligible Impact Determination
General Negligible Impact Analysis
Introduction
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In considering
how Level A harassment or Level B harassment (as presented in Table 28)
factor into the negligible impact analysis, in addition to considering
the number of estimated takes, NMFS considers other factors, such as
the likely nature of any responses (e.g., intensity, duration), the
context of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely
[[Page 46391]]
effectiveness of the mitigation. We also assess the number, intensity,
and context of estimated takes by evaluating this information relative
to population status. Consistent with the 1989 preamble for NMFS'
implementing regulations (54 FR 40338; September 29, 1989), the impacts
from other past and ongoing anthropogenic activities are incorporated
into this analysis via their impacts on the baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known).
In the Estimated Take of Marine Mammals section, we identified the
subset of potential effects that are expected to rise to the level of
takes both annually and over the seven-year period covered by this
rule, and then identified the maximum number of harassment takes that
are reasonably expected to occur based on the methods described. The
impact that any given take will have on an individual, and ultimately
the species or stock, is dependent on many case-specific factors that
need to be considered in the negligible impact analysis (e.g., the
context of behavioral exposures such as duration or intensity of a
disturbance, the health of impacted animals, the status of a species
that incurs fitness-level impacts to individuals, etc.). For this rule
we evaluated the likely impacts of the enumerated maximum number of
harassment takes reasonably expected to occur, and also authorized, in
the context of the specific circumstances surrounding these predicted
takes. Last, we collectively evaluated this information, as well as
other more taxa-specific information and mitigation measure
effectiveness, in group-specific assessments that support our
negligible impact conclusions for each species. Because the marine
mammal populations in the MITT Study Area have not been assigned to
stocks, all negligible impact analysis and determinations are at the
species level.
As explained in the Estimated Take of Marine Mammals section, no
take by serious injury or mortality is authorized or anticipated to
occur.
The Specified Activities reflect representative levels of training
and testing activities. The Description of the Specified Activity
section describes annual activities. There may be some flexibility in
the exact number of hours, items, or detonations that may vary from
year to year, but take totals will not exceed the seven-year totals
indicated in Table 28. We base our analysis and negligible impact
determination on the maximum number of takes that are reasonably
expected to occur and are authorized, although, as stated before, the
number of takes are only a part of the analysis, which includes
extensive qualitative consideration of other contextual factors that
influence the degree of impact of the takes on the affected
individuals. To avoid repetition, we provide some general analysis in
this General Negligible Impact Analysis section that applies to all the
species listed in Table 28, given that some of the anticipated effects
of the Navy's training and testing activities on marine mammals are
expected to be relatively similar in nature. Then, in the Group and
Species-Specific Analyses section, we subdivide into discussions of
Mysticetes and Odontocetes, as there are broad life history traits that
support an overarching discussion of some factors considered within the
analysis for those groups (e.g., high-level differences in feeding
strategies). Last, we break our analysis into species, or groups of
species where relevant similarities exist, to provide more specific
information related to the anticipated effects on individuals of that
species or where there is information about the status or structure of
any species that would lead to a differing assessment of the effects on
the species. Organizing our analysis by grouping species that share
common traits or that will respond similarly to effects of the Navy's
activities and then providing species-specific information allows us to
avoid duplication while assuring that we have analyzed the effects of
the specified activities on each affected species.
Harassment
The Navy's harassment take request is based on its model, as well
as the quantitative assessment of mitigation, which NMFS reviewed and
concurs appropriately predict the maximum amount of harassment that is
likely to occur. The model calculates sound energy propagation from
sonar, other active acoustic sources, and explosives during naval
activities; the sound or impulse received by animat dosimeters
representing marine mammals distributed in the area around the modeled
activity; and whether the sound or impulse energy received by a marine
mammal exceeds the thresholds for effects. Assumptions in the Navy
model intentionally err on the side of overestimation when there are
unknowns. Naval activities are modeled as though they would occur
regardless of proximity to marine mammals, meaning that no mitigation
is considered (e.g., no power down or shut down) and without any
avoidance of the activity by the animal. The final step of the
quantitative analysis of acoustic effects, which occurs after the
modeling, is to consider the implementation of mitigation and the
possibility that marine mammals would avoid continued or repeated sound
exposures. NMFS provided input to, independently reviewed, and
concurred with the Navy on this process and the Navy's analysis, which
is described in detail in Section 6 of the Navy's rulemaking/LOA
application, and was used to quantify harassment takes for this rule.
Generally speaking, the Navy and NMFS anticipate more severe
effects from takes resulting from exposure to higher received levels
(though this is in no way a strictly linear relationship for behavioral
effects throughout species, individuals, or circumstances) and less
severe effects from takes resulting from exposure to lower received
levels. However, there is also growing evidence of the importance of
distance in predicting marine mammal behavioral response to sound--
i.e., sounds of a similar level emanating from a more distant source
have been shown to be less likely to evoke a response of equal
magnitude (DeRuiter 2012, Falcone et al. 2017). The estimated number of
Level A harassment and Level B harassment takes does not equate to the
number of individual animals the Navy expects to harass (which is
lower), but rather to the instances of take (i.e., exposures above the
Level A harassment and Level B harassment threshold) that are
anticipated to occur annually and over the seven-year period. These
instances may represent either brief exposures (seconds or minutes) or,
in some cases, longer durations of exposure within a day. Some
individuals may experience multiple instances of take (meaning over
multiple days) over the course of the year, which means that the number
of individuals taken is smaller than the total estimated takes.
Generally speaking, the higher the number of takes as compared to the
population abundance, the more repeated takes of individuals are
likely, and the higher the actual percentage of individuals in the
population that are likely taken at least once in a year. We look at
this comparative metric to give us a relative sense of where a larger
portion of a species is being taken by Navy activities, where there is
a higher likelihood that the same individuals are being taken across
multiple days, and where that number of days might be higher or more
likely sequential. Where the number of instances of take is 100 percent
or less of the abundance and there is no information to specifically
suggest that a small subset of animals will be repeatedly taken over a
high
[[Page 46392]]
number of sequential days, the overall magnitude is generally
considered relatively low, as it could on one extreme mean that every
individual taken will be taken on no more than one day (a very minimal
impact) or, more likely, that some smaller portion of individuals are
taken on one day annually, some are taken on a few not likely
sequential days annually, and some are not taken at all.
In the ocean, the use of sonar and other active acoustic sources is
often transient and is unlikely to repeatedly expose the same
individual animals within a short period, for example within one
specific exercise. However, for some individuals of some species
repeated exposures across different activities could occur over the
year, especially where events occur in generally the same area with
more resident species. In short, for some species we expect that the
total anticipated takes represent exposures of a smaller number of
individuals of which some will be exposed multiple times, but based on
the nature of the Navy activities and the movement patterns of marine
mammals, it is unlikely that individuals from most species will be
taken over more than a few non-sequential days. This means that even
where repeated takes of individuals may occur, they are more likely to
result from non-sequential exposures from different activities. As
described elsewhere, the nature of the majority of the exposures is
expected to be of a less severe nature and based on the numbers it is
likely that any individual exposed multiple times is still only taken
on a small percentage of the days of the year.
Physiological Stress Response
Some of the lower level physiological stress responses (e.g.,
orientation or startle response, change in respiration, change in heart
rate) discussed in the proposed rule would likely co-occur with the
predicted harassments, although these responses are more difficult to
detect and fewer data exist relating these responses to specific
received levels of sound. Takes by Level B harassment, then, may have a
stress-related physiological component as well; however, we would not
expect the Navy's generally short-term, intermittent, and (typically in
the case of sonar) transitory activities to create conditions of long-
term, continuous noise leading to long-term physiological stress
responses in marine mammals that could affect reproduction or survival.
Behavioral Response
The estimates calculated using the behavioral response function do
not differentiate between the different types of behavioral responses
that rise to the level of take by Level B harassment. As described in
the Navy's application, the Navy identified (with NMFS' input) the
types of behaviors that would be considered a take (moderate behavioral
responses as characterized in Southall et al. (2007) (e.g., altered
migration paths or dive profiles, interrupted nursing, breeding or
feeding, or avoidance) that also would be expected to continue for the
duration of an exposure). The Navy then compiled the available data
indicating at what received levels and distances those responses have
occurred, and used the indicated literature to build biphasic
behavioral response curves and cutoff distances that are used to
predict how many instances of Level B harassment by behavioral
disturbance occur in a day. Take estimates alone do not provide
information regarding the potential fitness or other biological
consequences of the reactions on the affected individuals. We therefore
consider the available activity-specific, environmental, and species-
specific information to determine the likely nature of the modeled
behavioral responses and the potential fitness consequences for
affected individuals.
Use of sonar and other transducers will typically be transient and
temporary. The majority of acoustic effects to individual animals from
sonar and other active sound sources during testing and training
activities will be primarily from ASW events. It is important to note
that although ASW is one of the warfare areas of focus during MTEs,
there are significant periods when active ASW sonars are not in use.
Nevertheless, behavioral reactions are assumed more likely to be
significant during MTEs than during other ASW activities due to the
duration (i.e., multiple days), scale (i.e., multiple sonar platforms),
and use of high-power hull-mounted sonar in the MTEs. In other words,
in the range of potential behavioral effects that might be expected to
be part of a response that qualifies as an instance of Level B
harassment by behavioral disturbance (which by nature of the way it is
modeled/counted, occurs within one day), the less severe end might
include exposure to comparatively lower levels of a sound, at a
detectably greater distance from the animal, for a few or several
minutes. A less severe exposure of this nature could result in a
behavioral response such as avoiding an area that an animal would
otherwise have chosen to move through or feed in for some amount of
time or breaking off one or a few feeding bouts. More severe effects
could occur when the animal gets close enough to the source to receive
a comparatively higher level, is exposed continuously to one source for
a longer time, or is exposed intermittently to different sources
throughout a day. Such effects might result in an animal having a more
severe flight response and leaving a larger area for a day or more or
potentially losing feeding opportunities for a day. However, such
severe behavioral effects are expected to occur infrequently.
To help assess this, for sonar (LFAS/MFAS/HFAS) used in the MITT
Study Area, the Navy provided information estimating the percentage of
animals that may be taken by Level B harassment under each behavioral
response function that would occur within 6-dB increments (percentages
discussed below in the Group and Species-Specific Analyses section). As
mentioned above, all else being equal, an animal's exposure to a higher
received level is more likely to result in a behavioral response that
is more likely to lead to adverse effects, which could more likely
accumulate to impacts on reproductive success or survivorship of the
animal, but other contextual factors (such as distance) are important
also. The majority of Level B harassment takes are expected to be in
the form of milder responses (i.e., lower-level exposures that still
rise to the level of take) of a generally shorter duration. We
anticipate more severe effects from takes when animals are exposed to
higher received levels or at closer proximity to the source. However,
depending on the context of an exposure (e.g., depth, distance, if an
animal is engaged in important behavior such as feeding), a behavioral
response can vary between species and individuals within a species.
Specifically, given a range of behavioral responses that may be
classified as Level B harassment, to the degree that higher received
levels are expected to result in more severe behavioral responses, only
a smaller percentage of the anticipated Level B harassment from Navy
activities might necessarily be expected to potentially result in more
severe responses (see the Group and Species-Specific Analyses section
below for more detailed information). To fully understand the likely
impacts of the predicted/authorized take on an individual (i.e., what
is the likelihood or degree of fitness impacts), one must look closely
at the available contextual information,
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such as the duration of likely exposures and the likely severity of the
exposures (e.g., whether they will occur for a longer duration over
sequential days or the comparative sound level that will be received).
Ellison et al. (2012) and Moore and Barlow (2013), among others,
emphasize the importance of context (e.g., behavioral state of the
animals, distance from the sound source) in evaluating behavioral
responses of marine mammals to acoustic sources.
Diel Cycle
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing on a diel cycle (24-hour cycle). Behavioral
reactions to noise exposure, when taking place in a biologically
important context, such as disruption of critical life functions,
displacement, or avoidance of important habitat, are more likely to be
significant if they last more than one diel cycle or recur on
subsequent days (Southall et al., 2007). Henderson et al. (2016) found
that ongoing smaller scale events had little to no impact on foraging
dives for Blainville's beaked whale, while multi-day training events
may decrease foraging behavior for Blainville's beaked whale (Manzano-
Roth et al., 2016). Consequently, a behavioral response lasting less
than one day and not recurring on subsequent days is not considered
severe unless it could directly affect reproduction or survival
(Southall et al., 2007). Note that there is a difference between
multiple-day substantive behavioral reactions and multiple-day
anthropogenic activities. For example, just because an at-sea exercise
lasts for multiple days does not necessarily mean that individual
animals are exposed to those exercises for multiple days or, further,
exposed in a manner resulting in a sustained multiple day substantive
behavioral response. Large multi-day Navy exercises such as ASW
activities, typically include vessels that are continuously moving at
speeds typically 10-15 kn, or higher, and likely cover large areas that
are relatively far from shore (typically more than 3 nmi from shore)
and in waters greater than 600 ft deep. Additionally marine mammals are
moving as well, which will make it unlikely that the same animal could
remain in the immediate vicinity of the ship for the entire duration of
the exercise. Further, the Navy does not necessarily operate active
sonar the entire time during an exercise. While it is certainly
possible that these sorts of exercises could overlap with individual
marine mammals multiple days in a row at levels above those anticipated
to result in a take, because of the factors mentioned above, it is
considered unlikely for the majority of takes. However, it is also
worth noting that the Navy conducts many different types of noise-
producing activities over the course of the year and it is likely that
some marine mammals will be exposed to more than one and taken on
multiple days, even if they are not sequential.
That said, the MITT Study Area is different than other Navy ranges
where there can be a significant number of Navy surface ships with
hull-mounted sonar homeported. In the MITT Study Area, there are no
homeported surface ships with hull-mounted sonars permanently assigned.
There is no local unit level training in the MITT Study Area for
homeported ships such as the case for other ranges. Instead, Navy
activities from visiting and transiting vessels are much more episodic
in the MITT Study Area. Therefore, there could be long gaps between
activities (i.e., weeks, months) in the MITT Study Area.
Durations of Navy activities utilizing tactical sonar sources and
explosives vary and are fully described in Appendix A (Training and
Testing Activity Descriptions) of the 2020 MITT FSEIS/OEIS. Sonar used
during ASW will impart the greatest amount of acoustic energy of any
category of sonar and other transducers analyzed in the Navy's
rulemaking/LOA application and include hull-mounted, towed, line array,
sonobuoy, helicopter dipping, and torpedo sonars. Most ASW sonars are
MFAS (1-10 kHz); however, some sources may use higher or lower
frequencies. ASW training activities using hull-mounted sonar planned
for the MITT Study Area generally last for only a few hours (see Table
3). Some ASW training and testing can generally last for 2-10 days, or
a 10-day exercise is typical for an MTE-Large Integrated ASW (see Table
3). For these multi-day exercises there will typically be extended
intervals of non-activity in between active sonar periods. Because of
the need to train in a large variety of situations, the Navy does not
typically conduct successive ASW exercises in the same locations. Given
the average length of ASW exercises (times of sonar use) and typical
vessel speed, combined with the fact that the majority of the cetaceans
would not likely remain in proximity to the sound source, it is
unlikely that an animal would be exposed to LFAS/MFAS/HFAS at levels or
durations likely to result in a substantive response that would then be
carried on for more than one day or on successive days.
Most planned explosive events are scheduled to occur over a short
duration (1-8 hours); however, the explosive component of the activity
only lasts for minutes (see Table 3). Although explosive exercises may
sometimes be conducted in the same general areas repeatedly, because of
their short duration and the fact that they are in the open ocean and
animals can easily move away, it is similarly unlikely that animals
would be exposed for long, continuous amounts of time, or demonstrate
sustained behavioral responses. Although SINKEXs may last for up to 48
hrs (4-8 hrs, possibly 1-2 days), they are almost always completed in a
single day and only one event is planned annually for the MITT training
activities. They are stationary and conducted in deep, open water where
fewer marine mammals would typically be expected to be encountered.
They also have shutdown procedures and rigorous monitoring, i.e.,
during the activity, the Navy conducts passive acoustic monitoring and
visually observes for marine mammals 90 min prior to the first firing,
during the event, and 2 hrs after sinking the vessel. All of these
factors make it unlikely that individuals would be exposed to the
exercise for extended periods or on consecutive days.
Assessing the Number of Individuals Taken and the Likelihood of
Repeated Takes
As described previously, Navy modeling uses the best available
science to predict the instances of exposure above certain acoustic
thresholds, which are equated, as appropriate, to harassment takes
(and, for PTS, further corrected to account for mitigation and
avoidance). As further noted, for active acoustics it is more
challenging to parse out the number of individuals taken by Level B
harassment and the number of times those individuals are taken from
this larger number of instances. One method that NMFS can use to help
better understand the overall scope of the impacts is to compare these
total instances of take against the abundance of that species (or stock
if applicable). For example, if there are 100 estimated harassment
takes in a population of 100, one can assume either that every
individual will be exposed above acoustic thresholds in no more than
one day, or that some smaller number will be exposed in one day but a
few individuals will be exposed multiple days within a year and a few
not exposed at all. Where the number of instances of take exceed the
abundance of the population (i.e., are over 100 percent), multiple
takes of some individuals are predicted and expected to occur within a
year. Generally
[[Page 46394]]
speaking, the higher the number of takes as compared to the population
abundance, the more multiple takes of individuals are likely, and the
higher the actual percentage of individuals in the population that are
likely taken at least once in a year. We look at this comparative
metric to give us a relative sense of where larger portions of the
species or stocks are being taken by Navy activities and where there is
a higher likelihood that the same individuals may be taken across
multiple days and where that number of days might be higher. It also
provides a relative picture of the scale of impacts to each species.
In the ocean, unlike a modeling simulation with static animals, the
use of sonar and other active acoustic sources is often transient, and
is unlikely to repeatedly expose the same individual animals within a
short period, for example within one specific exercise. However, some
repeated exposures across different activities could occur over the
year with more resident species. Nonetheless, the episodic nature of
Navy activities in the MITT Study Area would mean less frequent
exposures as compared to some other ranges. While select offshore areas
in the MITT Study Area are used more frequently for ASW and other
activities, these are generally further offshore than where most island
associated resident populations would occur and instead would be in
areas with more transitory species. In short, we expect that the total
anticipated takes represent exposures of a smaller number of
individuals of which some could be exposed multiple times, but based on
the nature of the Navy's activities and the movement patterns of marine
mammals, it is unlikely that any particular subset would be taken over
more than a few non-sequential days.
In using the relationship between predicted instances of take and
the population abundance to help estimate the proportion of a
population likely taken and the number of days over which some
individuals may be taken, it is important to choose an appropriate
population estimate against which to make the comparison. The SARs,
where available, provide the official population estimate for a given
species or stock in U.S. waters in a given year (and are typically
based solely on the most recent survey data). When the stock is known
to range outside of U.S. EEZ boundaries, population estimates based on
surveys conducted only within the U.S. EEZ are known to be
underestimates. The marine mammal populations in the MITT Study Area
have not been assigned to specific stocks and there are no associated
SARs. There is also no information on trends for any of these species.
Nonetheless, the information used to estimate take included the best
available survey abundance data to model density layers. Further, in
calculating the percentage of takes versus abundance for each species
in order to assist in understanding both the percentage of the species
affected, as well as how many days across a year individuals could be
taken, we used the data most appropriate for the situation. The survey
data used to calculate abundance in the MITT Study Area is described in
the report Navy Marine Species Density Database Phase III for the
Mariana Islands Training and Testing Study Area (Navy 2018).
Temporary Threshold Shift
NMFS and the Navy have estimated that all species of marine mammals
may sustain some level of TTS from active sonar. As discussed in the
proposed rule in the Potential Effects of Specified Activities on
Marine Mammals and Their Habitat, in general, TTS can last from a few
minutes to days, be of varying degree, and occur across various
frequency bandwidths, all of which determine the severity of the
impacts on the affected individual, which can range from minor to more
severe. Tables 49-53 indicate the number of takes by TTS that may be
incurred by different species from exposure to active sonar and
explosives. The TTS sustained by an animal is primarily classified by
three characteristics:
1. Frequency--Available data (of mid-frequency hearing specialists
exposed to mid- or high-frequency sounds; Southall et al., 2007)
suggest that most TTS occurs in the frequency range of the source up to
one octave higher than the source (with the maximum TTS at \1/2\ octave
above). The Navy's MF sources, which are the highest power and most
numerous sources and the ones that cause the most take, utilize the 1-
10 kHz frequency band, which suggests that if TTS were to be induced by
any of these MF sources it would be in a frequency band somewhere
between approximately 2 and 20 kHz, which is in the range of
communication calls for many odontocetes, but below the range of the
echolocation signals used for foraging. There are fewer hours of HF
source use and the sounds would attenuate more quickly, plus they have
lower source levels, but if an animal were to incur TTS from these
sources, it would cover a higher frequency range (sources are between
10 and 100 kHz, which means that TTS could range up to 200 kHz), which
could overlap with the range in which some odontocetes communicate or
echolocate. However, HF systems are typically used less frequently and
for shorter time periods than surface ship and aircraft MF systems, so
TTS from these sources is unlikely. There are fewer LF sources and the
majority are used in the more readily mitigated testing environment,
but TTS from LF sources would most likely occur below 2 kHz, which is
in the range where many mysticetes communicate and also where other
non-communication auditory cues are located (waves, snapping shrimp,
fish prey). Also of note, the majority of sonar sources from which TTS
may be incurred occupy a narrow frequency band, which means that the
TTS incurred would also be across a narrower band (i.e., not affecting
the majority of an animal's hearing range). This frequency provides
information about the cues to which a marine mammal may be temporarily
less sensitive, but not the degree or duration of sensitivity loss. TTS
from explosives would be broadband.
2. Degree of the shift (i.e., by how many dB the sensitivity of the
hearing is reduced)--Generally, both the degree of TTS and the duration
of TTS will be greater if the marine mammal is exposed to a higher
level of energy (which would occur when the peak dB level is higher or
the duration is longer). The threshold for the onset of TTS was
discussed previously in this rule. An animal would have to approach
closer to the source or remain in the vicinity of the sound source
appreciably longer to increase the received SEL, which would be
difficult considering the Lookouts and the nominal speed of an active
sonar vessel (10-15 kn) and the relative motion between the sonar
vessel and the animal. In the TTS studies discussed in the Potential
Effects of Specified Activities on Marine Mammals and Their Habitat
section of the proposed rule, some using exposures of almost an hour in
duration or up to 217 SEL, most of the TTS induced was 15 dB or less,
though Finneran et al. (2007) induced 43 dB of TTS with a 64-second
exposure to a 20 kHz source. However, since any hull-mounted sonar,
such as the SQS-53, engaged in anti-submarine warfare training would be
moving at between 10 and 15 knots and nominally pinging every 50
seconds, the vessel will have traveled a minimum distance of
approximately 257 m during the time between those pings and, therefore,
incurring those levels of TTS is highly unlikely. A scenario could
occur where an animal does not leave the vicinity of a ship or travels
a course parallel to the ship, however, the close distances
[[Page 46395]]
required make TTS exposure unlikely. For a Navy vessel moving at a
nominal 10 knots, it is unlikely a marine mammal could maintain speed
parallel to the ship and receive adequate energy over successive pings
to suffer TTS.
In short, given the anticipated duration and levels of sound
exposure, we would not expect marine mammals to incur more than
relatively low levels of TTS (i.e., single digits of sensitivity loss).
To add context to this degree of TTS, individual marine mammals may
regularly experience variations of 6 dB differences in hearing
sensitivity across time (Finneran et al., 2000, 2002; Schlundt et al.,
2000).
3. Duration of TTS (recovery time)--In the TTS laboratory studies
(as discussed in the Potential Effects of Specified Activities on
Marine Mammals and Their Habitat section of the proposed rule), some
using exposures of almost an hour in duration or up to 217 SEL, almost
all individuals recovered within 1 day (or less, often in minutes),
although in one study (Finneran et al., 2007), recovery took 4 days.
Based on the range of degree and duration of TTS reportedly induced
by exposures to non-pulse sounds of energy higher than that to which
free-swimming marine mammals in the field are likely to be exposed
during LFAS/MFAS/HFAS training and testing exercises in the MITT Study
Area, it is unlikely that marine mammals would ever sustain a TTS from
MFAS that alters their sensitivity by more than 20 dB for more than a
few hours--and any incident of TTS would likely be far less severe due
to the short duration of the majority of the events and the speed of a
typical vessel, especially given the fact that the higher power sources
resulting in TTS are predominantly intermittent, which have been shown
to result in shorter durations of TTS. Also, for the same reasons
discussed in the Analysis and Negligible Impact Determination--Diel
Cycle section, and because of the short distance within which animals
would need to approach the sound source, it is unlikely that animals
would be exposed to the levels necessary to induce TTS in subsequent
time periods such that their recovery is impeded. Additionally, though
the frequency range of TTS that marine mammals might sustain would
overlap with some of the frequency ranges of their vocalization types,
the frequency range of TTS from MFAS would not usually span the entire
frequency range of one vocalization type, much less span all types of
vocalizations or other critical auditory cues for any given species.
Tables 47-51 indicate the number of incidental takes by TTS for
each species that are likely to result from the Navy's activities. As a
general point, the majority of these TTS takes are the result of
exposure to hull-mounted MFAS (MF narrower band sources), with fewer
from explosives (broad-band lower frequency sources), and even fewer
from LFAS or HFAS sources (narrower band). As described above, we
expect the majority of these takes to be in the form of mild (single-
digit), short-term (minutes to hours), narrower band (only affecting a
portion of the animal's hearing range) TTS. This means that for one to
several times per year, for several minutes to maybe a few hours (high
end) each, a taken individual will have slightly diminished hearing
sensitivity (slightly more than natural variation, but nowhere near
total deafness). More often than not, such an exposure would occur
within a narrower mid- to higher frequency band that may overlap part
(but not all) of a communication, echolocation, or predator range, but
sometimes across a lower or broader bandwidth. The significance of TTS
is also related to the auditory cues that are germane within the time
period that the animal incurs the TTS. For example, if an odontocete
has TTS at echolocation frequencies, but incurs it at night when it is
resting and not feeding, for example, it is not impactful. In short,
the expected results of any one of these small number of mild TTS
occurrences could be that (1) it does not overlap signals that are
pertinent to that animal in the given time period, (2) it overlaps
parts of signals that are important to the animal, but not in a manner
that impairs interpretation, or (3) it reduces detectability of an
important signal to a small degree for a short amount of time--in which
case the animal may be aware and be able to compensate (but there may
be slight energetic cost), or the animal may have some reduced
opportunities (e.g., to detect prey) or reduced capabilities to react
with maximum effectiveness (e.g., to detect a predator or navigate
optimally). However, given the small number of times that any
individual might incur TTS, the low degree of TTS and the short
anticipated duration, and the low likelihood that one of these
instances would occur in a time period in which the specific TTS
overlapped the entirety of a critical signal, it is unlikely that TTS
of the nature expected to result from the Navy activities would result
in behavioral changes or other impacts that would impact any
individual's (of any hearing sensitivity) reproduction or survival.
Auditory Masking or Communication Impairment
The ultimate potential impacts of masking on an individual (if it
were to occur) are similar to those discussed for TTS, but an important
difference is that masking only occurs during the time of the signal,
versus TTS, which continues beyond the duration of the signal.
Fundamentally, masking is referred to as a chronic effect because one
of the key potential harmful components of masking is its duration--the
fact that an animal would have reduced ability to hear or interpret
critical cues becomes much more likely to cause a problem the longer it
is occurring. Also inherent in the concept of masking is the fact that
the potential for the effect is only present during the times that the
animal and the source are in close enough proximity for the effect to
occur (and further, this time period would need to coincide with a time
that the animal was utilizing sounds at the masked frequency). As our
analysis has indicated, because of the relative movement of vessels and
the sound sources primarily involved in this rule, we do not expect the
exposures with the potential for masking to be of a long duration.
Masking is fundamentally more of a concern at lower frequencies,
because low frequency signals propagate significantly further than
higher frequencies and because they are more likely to overlap both the
narrower LF calls of mysticetes, as well as many non-communication cues
such as fish and invertebrate prey, and geologic sounds that inform
navigation. It should be noted that the Navy is only proposing
authorization for a small subset of more narrow frequency LF sources
and for less than 11 hours cumulatively annually. Masking is also more
of a concern from continuous sources (versus intermittent sonar
signals) where there is no quiet time between pulses within which
auditory signals can be detected and interpreted. For these reasons,
dense aggregations of, and long exposure to, continuous LF activity are
much more of a concern for masking, whereas comparatively short-term
exposure to the predominantly intermittent pulses of often narrow
frequency range MFAS or HFAS, or explosions are not expected to result
in a meaningful amount of masking. While the Navy occasionally uses LF
and more continuous sources, it is not in the contemporaneous aggregate
amounts that would accrue to a masking concern. Specifically, the
nature of the activities and sound sources used by the Navy do
[[Page 46396]]
not support the likelihood of a level of masking accruing that would
have the potential to affect reproductive success or survival.
Additional detail is provided below.
Standard hull-mounted MFAS typically pings every 50 seconds. Some
hull-mounted anti-submarine sonars can also be used in an object
detection mode known as ``Kingfisher'' mode (e.g., used on vessels when
transiting to and from port) where pulse length is shorter but pings
are much closer together in both time and space since the vessel goes
slower when operating in this mode. Kingfisher mode is typically
operated for relatively shorter durations. For the majority of other
sources, the pulse length is significantly shorter than hull-mounted
active sonar, on the order of several microseconds to tens of
milliseconds. Some of the vocalizations that many marine mammals make
are less than one second long, so, for example with hull-mounted sonar,
there would be a 1 in 50 chance (only if the source was in close enough
proximity for the sound to exceed the signal that is being detected)
that a single vocalization might be masked by a ping. However, when
vocalizations (or series of vocalizations) are longer than the one-
second pulse of hull-mounted sonar, or when the pulses are only several
microseconds long, the majority of most animals' vocalizations would
not be masked.
Most ASW sonars and countermeasures use MF frequencies and a few
use LF and HF frequencies. Most of these sonar signals are limited in
the temporal, frequency, and spatial domains. The duration of most
individual sounds is short, lasting up to a few seconds each. A few
systems operate with higher duty cycles or nearly continuously, but
they typically use lower power, which means that an animal would have
to be closer, or in the vicinity for a longer time, to be masked to the
same degree as by a higher level source. Nevertheless, masking could
occasionally occur at closer ranges to these high-duty cycle and
continuous active sonar systems, but as described previously, it would
be expected to be of a short duration when the source and animal are in
close proximity. While data are limited on behavioral responses of
marine mammals to continuously active sonars, mysticete species are
known to be able to habituate to novel and continuous sounds (Nowacek
et al., 2004), suggesting that they are likely to have similar
responses to high-duty cycle sonars. Furthermore, most of these systems
are hull-mounted on surface ships and ships are moving at least 10 kn,
and it is unlikely that the ship and the marine mammal would continue
to move in the same direction and the marine mammal subjected to the
same exposure due to that movement. Most ASW activities are
geographically dispersed and last for only a few hours, often with
intermittent sonar use even within this period. Most ASW sonars also
have a narrow frequency band (typically less than one-third octave).
These factors reduce the likelihood of sources causing significant
masking. HF signals (above 10 kHz) attenuate more rapidly in the water
due to absorption than do lower frequency signals, thus producing only
a very small zone of potential masking. If masking or communication
impairment were to occur briefly, it would more likely be in the
frequency range of MFAS (the more powerful source), which overlaps with
some odontocete vocalizations (but few mysticete vocalizations);
however, it would likely not mask the entirety of any particular
vocalization, communication series, or other critical auditory cue,
because the signal length, frequency, and duty cycle of the MFAS/HFAS
signal does not perfectly resemble the characteristics of any single
marine mammal species' vocalizations.
Other sources used in Navy training and testing that are not
explicitly addressed above, many of either higher frequencies (meaning
that the sounds generated attenuate even closer to the source) or lower
amounts of operation, are similarly not expected to result in masking.
For the reasons described here, any limited masking that could
potentially occur would be minor and short-term.
In conclusion, masking is more likely to occur in the presence of
broadband, relatively continuous noise sources such as from vessels,
however, the duration of temporal and spatial overlap with any
individual animal and the spatially separated sources that the Navy
uses would not be expected to result in more than short-term, low
impact masking that would not affect reproduction or survival.
Injury (Permanent Threshold Shift)
Tables 47 through 51 indicate the number of individuals of each
species for which Level A harassment in the form of PTS resulting from
exposure to active sonar and/or explosives is estimated to occur. The
number of individuals to potentially incur PTS annually (from sonar and
explosives) for each species ranges from 0 to 50 (50 is for Dwarf sperm
whale), but is more typically 0 or 1. As described previously, no
species are expected to incur tissue damage from explosives.
Data suggest that many marine mammals will deliberately avoid
exposing themselves to the received levels of active sonar necessary to
induce injury by moving away from or at least modifying their path to
avoid a close approach. Additionally, in the unlikely event that an
animal approaches the sonar-emitting vessel at a close distance, NMFS
has determined that the mitigation measures (i.e., shutdown/powerdown
zones for active sonar) would typically ensure that animals would not
be exposed to injurious levels of sound. As discussed previously, the
Navy utilizes both aerial (when available) and passive acoustic
monitoring (during ASW exercises, passive acoustic detections are used
as a cue for Lookouts' visual observations when passive acoustic assets
are already participating in an activity) in addition to Lookouts on
vessels to detect marine mammals for mitigation implementation. As
discussed previously, these Level A harassment take numbers represent
the maximum number of instances in which marine mammals would be
reasonably expected to incur PTS, and we have analyzed them
accordingly.
If a marine mammal is able to approach a surface vessel within the
distance necessary to incur PTS in spite of the mitigation measures,
the likely speed of the vessel (nominally 10-15 kn) and relative motion
of the vessel would make it very difficult for the animal to remain in
range long enough to accumulate enough energy to result in more than a
mild case of PTS. As discussed previously in relation to TTS, the
likely consequences to the health of an individual that incurs PTS can
range from mild to more serious depending upon the degree of PTS and
the frequency band it is in. The majority of any PTS incurred as a
result of exposure to Navy sources would be expected to be in the 2-20
kHz range (resulting from the most powerful hull-mounted sonar) and
could overlap a small portion of the communication frequency range of
many odontocetes, whereas other marine mammal groups have communication
calls at lower frequencies. Regardless of the frequency band though,
the more important point in this case is that any PTS accrued as a
result of exposure to Navy activities would be expected to be of a
small amount (single digits). Permanent loss of some degree of hearing
is a normal occurrence for older animals, and many animals are able to
compensate for the shift, both in old age or at younger ages as the
result of stressor exposure. While a small loss of hearing sensitivity
may
[[Page 46397]]
include some degree of energetic costs for compensating or may mean
some small loss of opportunities or detection capabilities, at the
expected scale it would be unlikely to impact behaviors, opportunities,
or detection capabilities to a degree that would interfere with
reproductive success or survival.
Group and Species-Specific Analyses
In this section, we build on the general analysis that applies to
all marine mammals in the MITT Study Area and Transit Corridor from the
previous section, and include first information and analysis that
applies to mysticetes or, separately, odontocetes, and then within
those two sections, more specific information that applies to smaller
groups, where applicable, and the affected species. The specific
authorized take numbers are also included in the analyses below, and so
here we provide some additional context and discussion regarding how we
consider the authorized take numbers in those analyses.
The maximum amount and type of incidental take of marine mammals
reasonably likely to occur from exposures to sonar and other active
acoustic sources and explosions and therefore authorized during the
seven-year training and testing period are shown in Table 28. The vast
majority of predicted exposures (greater than 99 percent) are expected
to be Level B harassment (TTS and behavioral reactions) from acoustic
and explosive sources during training and testing activities at
relatively low received levels.
In the discussions below, the estimated takes by Level B harassment
represent instances of take, not the number of individuals taken (the
much lower and less frequent takes by Level A harassment are far more
likely to be associated with separate individuals), and in some cases
individuals may be taken more than one time. Below, we compare the
total take numbers (including PTS, TTS, and behavioral disturbance) for
species to their associated abundance estimates to evaluate the
magnitude of impacts across the species and to individuals. Generally,
when an abundance percentage comparison is below 100, it suggests the
following: (1) That not all of the individuals will be taken; (2) that,
barring specific circumstances suggesting repeated takes of individuals
(such as in circumstances where all activities resulting in take are
focused in one area and time where the same individual marine mammals
are known to congregate, such as pinnipeds at a pupping beach), the
average or expected number of days taken for those individuals taken is
one per year; and (3) that we would not expect any individuals to be
taken more than a few times in a year, or for those days to be
sequential. There are no cases in this rule where the percentage of
takes as compared to abundance is greater than 100, the highest being
93 percent (for fin whales) and the remaining species at 55 percent or
less (most are 20 percent or under).
To assist in understanding what this analysis means, we clarify a
few issues related to estimated takes and the analysis here. An
individual that incurs a PTS or TTS take may sometimes, for example,
also be subject to behavioral disturbance at the same time. As
described above in this section, the degree of PTS, and the degree and
duration of TTS, expected to be incurred from the Navy's activities are
not expected to impact marine mammals such that their reproduction or
survival could be affected. Similarly, data do not suggest that a
single instance in which an animal incurs PTS or TTS and is also
subject to behavioral disturbance would result in impacts to
reproduction or survival. Alternately, we recognize that if an
individual is subjected to behavioral disturbance repeatedly for a
longer duration and on consecutive days, effects could accrue to the
point that reproductive success is jeopardized, although those sorts of
impacts are not expected to result from these activities. Accordingly,
in analyzing the number of takes and the likelihood of repeated and
sequential takes, we consider the total takes, not just the Level B
harassment takes by behavioral disruption, so that individuals
potentially exposed to both threshold shift and behavioral disruption
are appropriately considered. The number of Level A harassment takes by
PTS are so low (and zero in most cases) compared to abundance numbers
that it is considered highly unlikely that any individual would be
taken at those levels more than once.
Use of sonar and other transducers will typically be transient and
temporary. The majority of acoustic effects to mysticetes from sonar
and other active sound sources during testing and training activities
will be primarily from ASW events. It is important to note that
although ASW is one of the warfare areas of focus during MTEs, there
are significant periods when active ASW sonars are not in use.
Nevertheless, behavioral reactions are assumed more likely to be
significant during MTEs than during other ASW activities due to the
duration (i.e., multiple days) and scale (i.e., multiple sonar
platforms) of the MTEs. On the less severe end, exposure to
comparatively lower levels of sound at a detectably greater distance
from the animal, for a few or several minutes, could result in a
behavioral response such as avoiding an area that an animal would
otherwise have moved through or fed in, or breaking off one or a few
feeding bouts. More severe behavioral effects could occur when an
animal gets close enough to the source to receive a comparatively
higher level of sound, is exposed continuously to one source for a
longer time, or is exposed intermittently to different sources
throughout a day. Such effects might result in an animal having a more
severe flight response and leaving a larger area for a day or more, or
potentially losing feeding opportunities for a day. However, such
severe behavioral effects are expected to occur infrequently.
Occasional, milder behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations, and even if
some smaller subset of the takes are in the form of a longer (several
hours or a day) and more severe responses, if they are not expected to
be repeated over sequential days, impacts to individual fitness are not
anticipated. Nearly all studies and experts agree that infrequent
exposures of a single day or less are unlikely to impact an
individual's overall energy budget (Farmer et al., 2018; Harris et al.,
2017; King et al., 2015; NAS 2017; New et al., 2014; Southall et al.,
2007; Villegas-Amtmann et al., 2015).
If impacts to individuals are of a magnitude or severity such that
either repeated and sequential higher severity impacts occur (the
probability of this goes up for an individual the higher total number
of takes it has) or the total number of moderate to more severe impacts
occurs across sequential days, then it becomes more likely that the
aggregate effects could potentially interfere with feeding enough to
reduce energy budgets in a manner that could impact reproductive
success via longer cow-calf intervals, terminated pregnancies, or calf
mortality. It is important to note that if these impacts occurred they
would only accrue to females, which only comprise a portion of the
population (typically approximately 50 percent). Based on energetic
models, it takes energetic impacts of a significantly greater magnitude
to cause the death of an adult marine mammal, and females will always
terminate a pregnancy or stop lactating before allowing their health to
deteriorate. Also, the death of an adult female has significantly more
impact on population growth rates than reductions
[[Page 46398]]
in reproductive success, while the death of an adult male has very
little effect on population growth rates. However, as will be explained
further in the sections below, the severity and magnitude of takes
expected to result from the MITT activities are such that energetic
impacts of a scale that might affect reproductive success are not
expected to occur at all.
The analyses below in some cases address species collectively if
they occupy the same functional hearing group (i.e., low, mid, and
high-frequency cetaceans), share similar life history strategies, and/
or are known to behaviorally respond similarly to acoustic stressors.
Because some of these groups or species share characteristics that
inform the impact analysis similarly, it would be duplicative to repeat
the same analysis for each species. In addition, similar species
typically have the same hearing capabilities and behaviorally respond
in the same manner.
Thus, our analysis below considers the effects of the Navy's
activities on each affected species even where discussion is organized
by functional hearing group and/or information is evaluated at the
group level. Where there are meaningful differences between species
that would further differentiate the analysis, they are either
described within the section or the discussion for those species is
included as a separate subsection. Specifically below, we first give
broad descriptions of the mysticete and odontocete groups and then
differentiate into further groups and species as appropriate.
Mysticetes
This section builds on the broader discussion above and brings
together the discussion of the different types and amounts of take that
different species are likely to incur, the applicable mitigation, and
the status of the species to support the negligible impact
determinations for each species. We have described (above in the
General Negligible Impact Analysis section) the unlikelihood of any
masking having effects that would impact the reproduction or survival
of any of the individual marine mammals affected by the Navy's
activities. We also described in the Potential Effects of Specified
Activities on Marine Mammals and Their Habitat section of the proposed
rule the unlikelihood of any habitat impacts having effects that would
impact the reproduction or survival of any of the individual marine
mammals affected by the Navy's activities. No new information has been
received that affects that analysis and conclusion. There is no
predicted tissue damage from explosives for any species, and one
mother-calf pair of humpback whales could be taken by PTS by sonar
exposure over the course of the seven-year rule. Much of the discussion
below focuses on the behavioral effects and the mitigation measures
that reduce the probability or severity of effects. Because there are
species-specific considerations, at the end of the section we break out
our findings on a species-specific basis.
In Table 47 below for mysticetes, we indicate for each species the
total annual numbers of take by Level A and Level B harassment, and a
number indicating the instances of total take as a percentage of
abundance in the MITT Study Area alone, as well as the MITT Study Area
plus the Transit Corridor, which was calculated separately. While the
density used to calculate take is the same for these two areas, the
takes were calculated separately for the two areas for all species in
this rule, not just mysticetes, because the activity levels are higher
in the MITT Study Area and it is helpful to understand the comparative
impacts in the two areas. Note also that for mysticetes, the abundance
within the MITT Study Area and Transit Corridor represents only a
portion of the species abundance.
Table 47--Annual Estimated Takes by Level B Harassment and Level A Harassment for Mysticetes and Number Indicating the Instances of Total Take as a
Percentage of Abundance Within the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Abundance Instances of total
takes represent separate individuals, especially for ---------------------- take as percentage
disturbance) of abundance
------------------------------------------------------------- ---------------------
Level B harassment Level A Total takes MITT
Species --------------------------- harassment ---------------------- MITT study MITT
------------ MITT study area + MITT study
MITT study area transit study area +
Behavioral TTS study area + corridor area transit
disturbance PTS area transit corridor
corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale..................................... 4 20 0 24 24 134 150 18 16
Bryde's whale.................................. 40 258 0 296 298 1,470 1,596 20 19
Fin whale...................................... 5 20 0 25 25 27 46 93 54
Humpback whale................................. 92 679 * 2 768 771 2,393 2,673 20 32 18 29
Minke whale.................................... 10 85 0 95 95 403 450 23 21
Omura's whale.................................. 4 25 0 28 29 143 160 20 18
Sei whale...................................... 19 136 0 154 155 780 821 20 19
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
number in the Estimated Take of Marine Mammals section.
* There is one mother-calf pair of humpback whales estimated to be taken by Level A Harassment by PTS over the period of the rule. See the Estimated
Take of Marine Mammals section for further details.
The majority of takes by harassment of mysticetes in the MITT Study
Area will be caused by sources from the MF1 MFAS active sonar bin
(which includes hull-mounted sonar) because they are high level,
narrowband sources in the 1-10 kHz range, which intersect what is
estimated to be the most sensitive area of hearing for mysticetes. They
also are used in a large portion of exercises (see Tables 3 and 4).
Most of the takes (66 percent) from the MF1 bin in the MITT Study Area
would result from received levels between 154 and 172 dB SPL, while
another 33 percent would result from exposure between 172 and 178 dB
SPL. For the remaining active sonar bin types, the percentages are as
follows: LF4 = 97 percent between 124 and 136 dB SPL, MF4 = 99 percent
between 136 and 154 dB SPL, MF5 = 98 percent between 118 and 142 dB
SPL, and HF4 = 98 percent between 100 and 148 dB SPL. For explosives,
no blue whales or
[[Page 46399]]
fin whales will be taken by Level B harassment or Level A harassment
(PTS). For other mysticetes, exposure to explosives will result in
small numbers of take: 1-6 takes by Level B harassment by behavioral
disturbance per species, and 0-3 TTS takes per species (0 for Omura's
whales). Based on this information, the majority of the Level B
harassment by behavioral disturbance is expected to be of low to
sometimes moderate severity and of a relatively shorter duration. No
tissue damage from training and testing activities is anticipated or
authorized for any species.
Research and observations show that if mysticetes are exposed to
sonar or other active acoustic sources they may react in a number of
ways depending on the characteristics of the sound source, their
experience with the sound source, and whether they are migrating or on
seasonal feeding or breeding grounds. Behavioral reactions may include
alerting, breaking off feeding dives and surfacing, diving or swimming
away, or no response at all (DOD, 2017; Nowacek, 2007; Richardson,
1995; Southall et al., 2007). Overall, mysticetes have been observed to
be more reactive to acoustic disturbance when a noise source is located
directly on their migration route. Mysticetes disturbed while migrating
could pause their migration or route around the disturbance, while
males en route to breeding grounds have been shown to be less
responsive to disturbances. Although some may pause temporarily, they
will resume migration shortly after the exposure ends. Animals
disturbed while engaged in other activities such as feeding or
reproductive behaviors may be more likely to ignore or tolerate the
disturbance and continue their natural behavior patterns.
Alternately, adult female mysticetes with calves may be more
responsive to stressors. An increase in the disturbance level from
noise-generating human activities (such as, for example, sonar or
vessel traffic) may increase the risk of mother-calf pair separation
(reducing the time available for suckling) or require that louder
contact calls are made which, in turn increases the possibility of
detection. In either case, increased ambient noise could have negative
consequences for calf fitness (Cartwright and Sullivan 2009; Craig et
al., 2014).
Lactating humpback whale females mainly rest while stationary at
shallow depths within reach of the hull of commercial ships (although
not expected from Navy vessels for the reasons discussed in the
proposed rule and due to the effectiveness of mitigation measures),
increasing the potential for ship strike collisions; and even moderate
increases of noise from vessels can decrease the communication range
(Bejder et al., 2019). Videsen et al. (2017) reported that
vocalizations between humpback whale mothers and calves, which included
very weak tonal and grunting sounds, were produced more frequently
during active dives than suckling dives, suggesting that mechanical
stimuli rather than acoustic cues are used to initiate nursing. Their
study suggests that the use of mechanical cues for initiating suckling
and low level vocalizations with an active space of less than 100 m
indicate a strong selection pressure for acoustic crypsis. Furthermore,
such inconspicuous behavior likely reduces the risk of exposure to
eavesdropping predators and male humpback whale escorts that may
disrupt the high proportion of time spent nursing and resting, and
hence ultimately compromise calf fitness. Parks et al. (2019) explored
the potential for acoustic crypsis in North Atlantic right whale
mother-calf pairs. Their results show that right whale mother-calf
pairs have a strong shift in repertoire usage, significantly reducing
the number of higher amplitude, long-distance communication signals
they produced when compared with juvenile and pregnant whales in the
same habitat. Similarly, Nielsen et al. (2019) concluded that acoustic
crypsis in southern right whales and other baleen whales decreases the
risk of alerting potential predators and hence jeopardizing a
substantial energetic investment by the mother. These studies (i.e.,
Videsen et al., 2017; Parks et al., 2019; and Nielsen et al., 2019)
suggest that the small active space of the weak calls between baleen
whale mothers and calves is very sensitive to increases in ambient
noise from human encroachment, thereby increasing the risk of mother-
calf separation.
Few behavioral response studies have specifically looked at mother-
calf pairs; most studies have targeted adult animals. In the few
behavioral response studies where mothers with calves were targeted,
their responses were not different from those in groups without calves.
For example, humpback whales in a behavioral response experiment in
Australia responded to a 2 kHz tone stimulus by changing their course
during migration to move more offshore and surfaced more frequently,
but otherwise did not respond (Dunlop et al., 2013; Noad et al. 2013).
Mother-calf pairs, either alone or with escorts, did not respond any
differently to the tonal stimulus than groups without calves. Several
humpback whales on breeding grounds have been observed during aerial or
visual surveys during Navy training events involving sonar; no
avoidance or other behavioral responses were ever noted, even when the
whales were observed within 5 km of a vessel with active (or possibly
active) sonar and maximum received levels were estimated to be between
135 and 161 dB re 1 [micro]Pa (Smultea et al., 2009; Mobley et al.
2009; Mobley and Milette 2010; Mobley 2011; Mobley and Pacini 2012;
Mobley et al., 201; Smultea et al., 2012).
As noted in the Potential Effects of Specified Activities on Marine
Mammals and Their Habitat section of the proposed rule, while there are
multiple examples from behavioral response studies of odontocetes
ceasing their feeding dives when exposed to sonar pulses at certain
levels, alternately blue whales (mysticetes) were less likely to show a
visible response to sonar exposures at certain levels when feeding than
when traveling. However, Goldbogen et al. (2013) indicated some
horizontal displacement of deep foraging blue whales in response to
simulated MFAS. Southall et al. (2019b) observed that after exposure to
simulated and operational mid-frequency active sonar, more than 50
percent of blue whales in deep-diving states responded to the sonar,
while no behavioral response was observed in shallow-feeding blue
whales. Southall et al. (2019b) noted that the behavioral responses
they observed were generally brief, of low to moderate severity, and
highly dependent on exposure context (behavioral state, source-to-whale
horizontal range, and prey availability). Most Level B harassment by
behavioral disturbance of mysticetes is likely to be short-term and of
low to sometimes moderate severity, with no anticipated effect on
reproduction or survival.
Richardson et al. (1995) noted that avoidance (temporary
displacement of an individual from an area) reactions are the most
obvious manifestations of disturbance in marine mammals. Avoidance is
qualitatively different from the startle or flight response, but also
differs in the magnitude of the response (i.e., directed movement, rate
of travel, etc.). Oftentimes avoidance is temporary, and animals return
to the area once the noise has ceased. Some mysticetes may avoid larger
activities such as a MTE as they move through an area, although these
activities do not typically use the same training locations day-after-
day during multi-day activities, except periodically in instrumented
ranges, which do not occur within the MITT Study Area.
[[Page 46400]]
Therefore, displaced animals could return quickly after a large
activity or MTE is completed. Due to the limited number and geographic
scope of MTEs, it is unlikely that most mysticetes would encounter an
MTE more than once per year and additionally, total hull-mounted sonar
hours would be limited in several areas that are important to
mysticetes (described below). In the ocean, the use of Navy sonar and
other active acoustic sources is transient and is unlikely to expose
the same population of animals repeatedly over a short period of time,
especially given the broader-scale movements of mysticetes.
The implementation of procedural mitigation and the sightability of
mysticetes (especially given their large size) further reduces the
potential for a significant behavioral reaction or a threshold shift to
occur (i.e., shutdowns are expected to be successfully implemented),
which is reflected in the amount and type of incidental take that is
anticipated to occur and authorized.
As noted previously, when an animal incurs a threshold shift, it
occurs in the frequency from that of the source up to one octave above.
This means that the vast majority of threshold shifts caused by Navy
sonar sources will typically occur in the range of 2-20 kHz (from the
1-10 kHz MF1 bin, though in a specific narrow band within this range as
the sources are narrowband), and if resulting from hull-mounted sonar,
will be in the range of 3.5-7 kHz. The majority of mysticete
vocalizations occur in frequencies below 1 kHz, which means that TTS
incurred by mysticetes will not interfere with conspecific
communication. Additionally, many of the other critical sounds that
serve as cues for navigation and prey (e.g., waves, fish,
invertebrates) occur below a few kHz, which means that detection of
these signals will not be inhibited by most threshold shift either.
When we look in ocean areas where the Navy has been intensively
training and testing with sonar and other active acoustic sources for
decades, there is no data suggesting any long-term consequences to
reproduction or survival rates of mysticetes from exposure to sonar and
other active acoustic sources.
All the mysticete species discussed in this section will benefit
from the procedural mitigation measures described earlier in the
Mitigation Measures section. Additionally, the Navy will limit
activities and employ other measures in mitigation areas that will
avoid or reduce impacts to humpback whales (discussed in detail below).
Below we compile and summarize the information that supports our
determination that the Navy's activities will not adversely affect any
species through effects on annual rates of recruitment or survival for
any of the affected mysticete species.
Humpback whale--As noted in the Description of Marine Mammals and
Their Habitat in the Area of the Specified Activities section, humpback
whales in the Mariana Islands are considered most likely part of the
ESA-endangered WNP DPS and the Mariana Archipelago is an established
breeding ground. No ESA Critical Habitat has been proposed in the MITT
Study Area. However, the areas of Marpi and Chalan Kanoa Reefs (out to
the 400-m isobath) are known specifically to be used by mother/calf
pairs of humpback whales (Hill et al., 2016, 2017, 2018, 2020).
Currently, no other areas have been identified for mother/calf pairs of
humpback whales in the Mariana Islands. The current population trend
for the WPN DPS of humpback whales show the SPLASH abundance estimate
for Asia represents a 6.7 percent annual rate of increase over the 1991
to 1993 abundance estimate (Calambokidis et al., 2008). However, the
1991 to 1993 estimate was for Ogasawara and Okinawa only, whereas the
SPLASH estimate includes the Philippines, so the annual rate of
increase is unknown. The population trend for WNP DPS of humpback is
unknown (NMFS 2019).
Regarding the consideration of how Navy activities may affect
humpback whales in these important areas with calves, as described
previously, this final rule includes the Chalan Kanoa Reef and Marpi
Reef Geographic Mitigation Areas, which encompass the area of observed
calf detections and include water depths of 400 m or less, with
significant parts of the mitigation areas less than 200 m, which is
where most humpback whale sightings have been made. The Navy will not
use explosives in the Marpi Reef and Chalan Kanoa Reef Geographic
Mitigation Areas year-round. These two geographic mitigation areas also
will require a 20-hour annual cap (for both areas combined) from
December 1 through April 30 on MF1 MFAS use to minimize sonar exposure
and reduce take by Level B harassment of humpback whales in these
important reproductive areas.
The Navy expects current and future use of these two Geographic
Mitigation Areas to remain low, but the 20-hour cap allows for the Navy
to engage in a small amount of necessary training, most likely such as
a Small Coordinated ASW Exercise or TRACKEX event(s), which could, for
example, occur up to five days, but no more than four hours per day (or
similar configuration totaling no more than 20 hours annually). As
described in the Humpback Whales Around Saipan subsection of the
Estimated Take of Marine Mammals section, our updated analysis
indicates that given the maximum of 20 hrs of MF1 MFAS, a maximum
annual total of 305 instances of Level B harassment may be incurred by
61 humpback whales, including 17 calves, in these areas during these
months in the Geographic Mitigation Areas. One mother-calf pair of
humpback whales may be taken by Level A harassment in the form of PTS
over the course of the seven years of activities in these areas.
Because of the higher density of humpback whales in this area, these
individuals could potentially be taken on up to five, most likely non-
sequential days. However, the reduction in exposure of humpback whales
to sonar and explosive detonations in the Geographic Mitigation Areas
and at this time (i.e., the short overall and daily exposure) will
reduce the likelihood of impacts that could affect reproduction or
survival, by minimizing impacts on calves during this sensitive life
stage, avoiding the additional energetic costs to mothers of avoiding
the area during explosive exercises, and minimizing the chances that
important breeding behaviors are interrupted to the point that
reproduction is inhibited or abandoned for the year, or otherwise
interfered with. Finally, the Navy will also implement the Marpi Reef
and Chalan Kanoa Reef Awareness Notification Message Area that will
help alert Navy vessels operating in these areas to the possible
presence of increased concentrations of humpback whales from December 1
through April 30 to avoid interactions with large whales that may be
vulnerable to vessel strikes.
To be clear about the temporal and spatial distribution of the
estimated take, all take of humpback whales is expected to occur from
December through April (the months when humpback whales are located in
the MITT Study Area), with the number noted in the previous paragraph
occurring in the two mitigation areas, and the remainder occurring
throughout the MITT Study Area and Transit Corridor. Regarding the
magnitude of takes by Level B harassment (TTS and behavioral
disruption), the number of estimated total instances of take compared
to the abundance (measured against both the MITT Study Area abundance
and the MITT Study Area plus the transit corridor abundance
[[Page 46401]]
combined) is 32 and 29 percent, respectively (Table 47). Regarding the
severity of those individual takes by Level B harassment by behavioral
disturbance, we have explained that the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 172 dB with a portion up to 178
dB (i.e., of a moderate or lower level, less likely to evoke a severe
response). While impacts to cow-calf pairs are of particular concern,
we have also explained how the restrictions and limitations on
explosive and sonar use in the geographic mitigation areas will
minimize impacts. Regarding the severity of takes by TTS, they are
expected to be low-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with communication
or other important low-frequency cues. Therefore the associated lost
opportunities and capabilities are not at a level that will impact
reproduction or survival.
Altogether, the WNP DPS of humpback whales is endangered and while
there is not enough information to identify a population trend, the
Mariana Archipelago has been identified as a breeding area for the WNP
DPS of humpback whales. In consideration of the MITT Study Area as a
whole, only a small portion of the total individuals within the MITT
Study Area will be taken and disturbed at a low-moderate level, with
most of those individuals likely not disturbed on more than a few non-
sequential days in a year. As described above for the mitigation areas
specifically, if the Navy conducts the maximum five 4-hour exercises in
these areas, cow-calf pairs could be taken on up to five likely non-
sequential days. However, takes in these mitigation areas would be as a
result of brief exposure to one shorter-duration exercise (as discussed
earlier, the duration of an exercise does not indicate the duration of
exposure to the exercises, which would be significantly shorter given
the speed of Navy vessels), and the impacts would not be expected to
accrue to the degree that would interfere with important mother-calf
communications in a manner leading to cow-calf separation, interfere
with social communications in a manner that would impede breeding, or
impact humpback cow behaviors in a manner that would have adverse
impacts on their energy budget and lactation success. One mother-calf
pair could be taken by a small amount of PTS over the course of these
seven-year regulations, of likely low severity as described previously.
A small permanent loss of hearing sensitivity (PTS) may include some
degree of energetic costs for compensating or may mean some small loss
of opportunities or detection capabilities for the individual. However,
given the smaller degree of PTS, and higher frequency of the hearing
loss anticipated to result from MF1 sonar exposure (which is above the
frequencies used to communicate with conspecifics and, specifically,
calves), the PTS incurred by one mother-calf pair of humpback whales in
a given year is unlikely to impact its behaviors, opportunities, or
detection capabilities to a degree that will interfere with
reproductive success or survival of the individual, let alone affect
annual rates of recruitment or survival.
Even considering the potential impacts to cow-calf pairs, given the
historic low use in the shallow waters of Marpi and Chalan Kanoa Reefs
for Navy's activities as well as the restriction on explosive use and a
20-hr cap on MFAS, as well as the low magnitude and severity of
anticipated harassment effects, the authorized takes are not expected
to result in impacts on the reproduction or survival of any
individuals, let alone have impacts on annual rates of recruitment or
survival. Therefore, the total take will not adversely affect this
species through impacts on annual rates of recruitment or survival. No
mortality is anticipated or authorized. For these reasons, we have
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take will have a negligible
impact on humpback whales.
Blue whale--Blue whales are listed as endangered under the ESA
throughout their range, with no ESA-designated critical habitat or
known biologically important areas identified for this species in the
MITT Study Area. There have been no stock(s) specified for the blue
whales found in the MITT Study Area and Transit Corridor, and there is
no associated SAR. There is also no information on trends for this
species within the MITT Study Area. Blue whales are however considered
stable generally throughout their range (NMFS 2019). Blue whales would
be most likely to occur in the MITT Study Area during the winter and
are expected to be few in number. There are no recent sighting records
for blue whales in the MITT Study Area (Fulling et al., 2011; Hill et
al., 2017a; Uyeyama, 2014). However, some acoustic detections from
passive monitoring devices deployed at Saipan and Tinian have recorded
the presence of blue whales over short periods of time (a few days)
(Oleson et al., 2015). Since blue whale calls can travel very long
distances (up to 621 mi (1,000 km)), it is unknown whether the animals
were within the MITT Study Area.
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disruption), the number of estimated total instances of take
compared to the abundance (measured against both the MITT Study Area
abundance and the MITT Study Area plus the transit corridor combined)
is 18 and 16 percent, respectively (Table 47). Regarding the severity
of those individual takes by Level B harassment by behavioral
disturbance, we have explained that the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 172 dB with a portion up to 178
dB (i.e., of a moderate or lower level, less likely to evoke a severe
response). Regarding the severity of TTS takes, they are expected to be
low-level, of short duration, and mostly not in a frequency band that
would be expected to interfere with communication or other important
low-frequency cues. Therefore the associated lost opportunities and
capabilities are not at a level that will impact reproduction or
survival.
Altogether, blue whales are listed as endangered, there are no
known population trends, and blue whales have a very large range and a
low abundance in the MITT Study Area. Our analysis suggests that a
small portion of the individuals in the MITT Study Area and Transit
Corridor (which represent only a small portion of the total abundance
of the species) will be taken and disturbed at a low-moderate level,
with those individuals disturbed on likely one day within a year. No
mortality or Level A harassment is anticipated or authorized. This low
magnitude and severity of harassment effects is not expected to result
in impacts on the reproduction or survival of any individuals and,
therefore, the total take will not adversely affect this species
through impacts on annual rates of recruitment or survival, let alone
have impacts on annual rates of recruitment or survival. For these
reasons, we have determined, in consideration of all of the effects of
the Navy's activities combined, that the authorized take will have a
negligible impact on blue whales.
Fin whale--Fin whales are listed as endangered under the ESA
throughout their range, with no ESA designated critical habitat or
known biologically important areas identified for this species in the
MITT Study Area. There have been no stock(s) specified for fin
[[Page 46402]]
whales found in the MITT Study Area and Transit Corridor, and there is
no associated SAR. There is also no information on trends for this
species within the MITT Study Area or in other parts of their range
(NMFS 2019). There are no sighting records for fin whales in the MITT
Study Area (Fulling et al., 2011; Hill et al., 2017a; Oleson et al.,
2015; Uyeyama, 2014). However, based on acoustic detections, fin whales
are expected to be present in the MITT Study Area, although few in
number.
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disruption), the number of estimated total instances of take
compared to the abundance (measured against both the MITT Study Area
abundance and the MITT Study Area plus the transit corridor combined)
is 93 and 54 percent, respectively (Table 47). Regarding the severity
of those individual takes by Level B harassment by behavioral
disturbance, we have explained that the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 172 dB with a portion up to 178
dB (i.e., of a moderate or lower level, less likely to evoke a severe
response). Regarding the severity of TTS takes, they are expected to be
low-level, of short duration, and mostly not in a frequency band that
would be expected to interfere with communication or other important
low-frequency cues. Therefore, the associated lost opportunities and
capabilities are not at a level that will impact reproduction or
survival.
Altogether, fin whales are listed as endangered, there are no known
population trends, and they have a low abundance in the MITT Study
Area. Our analysis suggests that up to half or more of the individuals
in the MITT Study Area and Transit Corridor (which represent a small
portion of the species abundance) will be taken and disturbed at a low-
moderate level, with those individuals likely not disturbed on more
than a few non-sequential days a year. No mortality or Level A
harassment is anticipated or authorized. This low magnitude and
severity of harassment effects is not expected to result in impacts on
the reproduction or survival of any individuals, let alone have impacts
on annual rates of recruitment or survival, and therefore the total
take will not adversely affect this species through impacts on annual
rates of recruitment or survival. For these reasons, we have
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take will have a negligible
impact on fin whales.
Sei whale--Sei whales are listed as endangered under the ESA
throughout their range, with no ESA-designated critical habitat or
known biologically important areas identified for this species in the
MITT Study Area. There have been no stock(s) specified for sei whales
found in the MITT Study Area and Transit Corridor, and there are no
associated SARs. There is also no information on population trends for
this species within the MITT Study Area or in other parts of their
range (NMFS 2019).
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disruption), the number of estimated total instances of take
compared to the abundance (measured against both the MITT Study Area
abundance and the MITT Study Area plus the transit corridor combined)
is 20 and 19 percent, respectively (Table 47). Regarding the severity
of those individual takes by Level B harassment by behavioral
disturbance, we have explained that the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 172 dB with a portion up to 178
dB (i.e., of a moderate or lower level, less likely to evoke a severe
response). Regarding the severity of TTS takes, they are expected to be
low-level, of short duration, and mostly not in a frequency band that
would be expected to interfere with communication or other important
low-frequency cues. Therefore the associated lost opportunities and
capabilities are not at a level that will impact reproduction or
survival.
Altogether sei whales are listed as endangered, there are no known
population trends. Our analysis suggests that a small portion of
individuals within the MITT Study Area and Transit Corridor (which is a
small portion of the species abundance) will be taken and disturbed at
a low-moderate level, with those individuals disturbed on likely one
day within a year. No mortality or Level A harassment is anticipated or
authorized. This low magnitude and severity of harassment effects is
not expected to result in impacts on the reproduction or survival of
any individuals, let alone have impacts on annual rates of recruitment
or survival. Therefore, the total take will not adversely affect this
species through impacts on annual rates of recruitment or survival. For
these reasons, we have determined, in consideration of all of the
effects of the Navy's activities combined, that the authorized take
will have a negligible impact on sei whales.
Bryde's whale, Minke whale, and Omura's whale--None of these
species of whales are listed as endangered or threatened under the ESA
and there are no known biologically important areas identified for
these species in the MITT Study Area. There have been no specific
stock(s) specified for these populations found in the MITT Study Area
and Transit Corridor, and there are no associated SARs. There is also
no information on population trends for these species within the MITT
Study Area.
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the MITT Study
Area abundance and the MITT Study Area plus the transit corridor
combined) is 20 and 19 percent (Bryde's whale), 23 and 21 percent
(Minke whale), and 20 and 18 (Omura's whale) percent, respectively
(Table 47). Regarding the severity of those individual takes by Level B
harassment by behavioral disturbance, we have explained that the
duration of any exposure is expected to be between minutes and hours
(i.e., relatively short) and the received sound levels largely below
172 dB with a portion up to 178 dB (i.e., of a moderate or lower level,
less likely to evoke a severe response). Regarding the severity of TTS
takes, they are expected to be low-level, of short duration, and mostly
not in a frequency band that would be expected to interfere with
communication or other important low-frequency cues. Therefore, the
associated lost opportunities and capabilities are not at a level that
will impact reproduction or survival.
Altogether, these three species of whales are not listed under the
ESA and there are no known population trends. The abundance of Bryde's
whales, minke whales, and Omura's whales in the MITT Study Area is
thought to be low, and our analysis suggests that a small portion of
individuals within the MITT Study Area and Transit Corridor will be
taken and disturbed at a low-moderate level, with those individuals
disturbed only once. No mortality or Level A harassment is anticipated
or authorized. This low magnitude and severity of harassment effects is
not expected to result in impacts on the reproduction or survival of
any individuals, let alone have impacts on annual rates of recruitment
or survival. Therefore, the total take will not adversely affect these
species through impacts on annual rates of recruitment
[[Page 46403]]
or survival. For these reasons, we have determined, in consideration of
all of the effects of the Navy's activities combined, that the
authorized take will have a negligible impact on Bryde's whales, minke
whales, and Omura's whales.
Odontocetes
This section builds on the broader discussion above and brings
together the discussion of the different types and amounts of take that
different species are likely to incur, the applicable mitigation for
each species, and the status of the species to support the negligible
impact determinations for each species. We have described (above in the
General Negligible Impact Analysis section) the unlikelihood of any
masking having effects that would impact the reproduction or survival
of any of the individual marine mammals affected by the Navy's
activities. We also described in the Potential Effects of Specified
Activities on Marine Mammals and Their Habitat section of the proposed
rule the unlikelihood of any habitat impacts having effects that would
impact the reproduction or survival of any of the individual marine
mammals affected by the Navy's activities. No new information has been
received that affects the analysis and conclusion. There is no
predicted PTS from sonar or explosives for most odontocetes, with the
exception of a few species which is discussed below. There is no
predicted tissue damage from explosives for any species. Much of the
discussion below focuses on the behavioral effects and the mitigation
measures that reduce the probability or severity of effects. Here, we
include information that applies to all of the odontocete species,
which are then further divided and discussed in more detail in the
following subsections: Dwarf sperm whales and pygmy sperm whales; sperm
whales; beaked whales; and dolphins and small whales. These subsections
include more specific information about the groups, as well as
conclusions for each species represented.
The majority of takes by harassment of odontocetes in the MITT
Study Area will be caused by sources from the MFAS bin (which includes
hull-mounted sonar) because they are high level, typically narrowband
sources at a frequency (in the 1-10 kHz range) that overlaps a more
sensitive portion (though not the most sensitive) of the MF hearing
range and they are used in a large portion of exercises (see Table 3).
For odontocetes other than beaked whales (for which these percentages
are indicated separately in that section), most of the takes (98
percent) from the MF1 bin in the MITT Study Area would result from
received levels between 154 and 172 dB SPL. For the remaining active
sonar bin types, the percentages are as follows: LF4 = 97 percent
between 124 and 136 dB SPL, MF4 = 99 percent between 136 and 160 dB
SPL, MF5 = 97 percent between 118 and 142 dB SPL, and HF4 = 88.6
percent between 100 and 130 dB SPL. Based on this information, the
majority of the takes by Level B harassment by behavioral disturbance
are expected to be low to sometimes moderate in nature, but still of a
generally shorter duration.
For all odontocetes, takes from explosives (Level B harassment by
behavioral disturbance or TTS, or PTS) comprise a very small fraction
(and low number) of those caused by exposure to active sonar. For the
following odontocetes, zero takes from explosives are expected to
occur: Blainville's beaked whales, Cuvier's beaked whales, bottlenose
dolphins, false killer whales, killer whales, sperm whales, rough-
toothed dolphins, and pygmy killer whales. For Level B harassment by
behavioral disturbance from explosives, 1 to 4 takes are expected to
occur for all but two of the remaining odontocetes, 25 and 64 takes for
pygmy and dwarf sperm whales, respectively. Similarly, the instances of
PTS and TTS from explosives are expected to be low. The instances of
TTS expected to occur from explosives are 0 to 5 per species and the
instances of PTS expected to occur from explosives are 0 to 1 per
species, except for pygmy and dwarf sperm whales. Because of the lower
TTS and PTS thresholds for HF odontocetes, pygmy and dwarf sperm whales
are expected to have 25 and 64 takes by Level B harassment disturbance
and 37 and 100 takes by TTS, and 8 and 21 takes by PTS from explosives,
respectively.
Because the majority of harassment takes of odontocetes result from
the sources in the MFAS bin, the vast majority of threshold shift would
occur at a single frequency within the 1-10 kHz range and, therefore,
the vast majority of threshold shift caused by Navy sonar sources would
be at a single frequency within the range of 2-20 kHz. The frequency
range within which any of the anticipated narrowband threshold shift
would occur would fall directly within the range of most odontocete
vocalizations (2-20 kHz). For example, the most commonly used hull-
mounted sonar has a frequency around 3.5 kHz, and any associated
threshold shift would be expected to be at around 7 kHz. However,
individual odontocete vocalizations typically span a much wider range
than this, and alternately, threshold shift from active sonar will
often be in a narrower band (reflecting the narrower band source that
caused it), which means that TTS incurred by odontocetes would
typically only interfere with communication within a portion of their
range (if it occurred during a time when communication with
conspecifics was occurring) and, as discussed earlier, it would only be
expected to be of a short duration and relatively small degree.
Odontocete echolocation occurs predominantly at frequencies
significantly higher than 20 kHz, though there may be some small
overlap at the lower part of their echolocating range for some species,
which means that there is little likelihood that threshold shift,
either temporary or permanent would interfere with feeding behaviors.
Many of the other critical sounds that serve as cues for navigation and
prey (e.g., waves, fish, invertebrates) occur below a few kHz, which
means that detection of these signals will not be inhibited by most
threshold shift either. The low number of takes by threshold shift that
might be incurred by individuals exposed to explosives would likely be
lower frequency (5 kHz or less) and spanning a wider frequency range,
which could slightly lower an individual's sensitivity to navigational
or prey cues, or a small portion of communication calls, for several
minutes to hours (if temporary) or permanently. There is no reason to
think that any of the individual odontocetes taken by TTS would incur
these types of takes over more than one day, or over a few days at
most, and therefore they are unlikely to incur impacts on reproduction
or survival. The number of PTS takes from these activities are very low
(0 annually for most, 1 for a few species, and 19 and 50 for pygmy and
dwarf sperm whales, respectively), and as discussed previously because
of the low degree of PTS (i.e., low amount of hearing sensitivity
loss), as well as the narrower frequency range in which the majority of
the PTS would occur, it is unlikely to affect reproduction or survival
of any individuals..
The range of potential behavioral effects of sound exposure on
marine mammals generally, and odontocetes specifically, has been
discussed in detail previously. There are behavioral patterns that
differentiate the likely impacts on odontocetes as compared to
mysticetes. First, odontocetes echolocate to find prey, which means
that they actively send out sounds to detect their prey. While there
are many strategies for hunting, one common
[[Page 46404]]
pattern, especially for deeper diving species, is many repeated deep
dives within a bout, and multiple bouts within a day, to find and catch
prey. As discussed above, studies demonstrate that odontocetes may
cease their foraging dives in response to sound exposure. If enough
foraging interruptions occur over multiple sequential days, and the
individual either does not take in the necessary food, or must exert
significant effort to find necessary food elsewhere, energy budget
deficits can occur that could potentially result in impacts to
reproductive success, such as increased cow/calf intervals (the time
between successive calving). Second, while many mysticetes rely on
seasonal migratory patterns that position them in a geographic location
at a specific time of the year to take advantage of ephemeral large
abundances of prey (i.e., invertebrates or small fish, which they eat
by the thousands), odontocetes forage more homogeneously on one fish or
squid at a time. Therefore, if odontocetes are interrupted while
feeding, it is often possible to find more prey relatively nearby.
Dwarf Sperm Whales and Pygmy Sperm Whales (Kogia species)--This
section builds on the broader odontocete discussion above and brings
together the discussion of the different types and amounts of take that
these two species are likely to incur, the applicable mitigation, and
the status of the species to support the negligible impact
determinations for each species. Some Level A harassment by PTS is
anticipated annually (50 and 19 takes for Dwarf and pygmy whale,
respectively, see Table 48).
In Table 48 below for dwarf sperm whales and pygmy sperm whales, we
indicate for each species the total annual numbers of take by Level A
and Level B harassment, and a number indicating the instances of total
take as a percentage of the abundance within the MITT Study Area alone,
as well as the MITT Study Area plus the Transit Corridor, which was
calculated separately. While the density used to calculate take is the
same for these two areas, the takes were calculated separately for the
two areas for dwarf and pygmy sperm whales because the activity levels
are higher in the MITT Study Area and it is helpful to understand the
comparative impacts in the two areas. Note also that for dwarf and
pygmy sperm whales (and all odontocetes), the abundance within the MITT
Study Area and Transit Corridor represents only a portion of the
species abundance.
Table 48--Annual Estimated Takes by Level B Harassment and Level A Harassment for Dwarf Sperm Whales and Pygmy Sperm Whales and Number Indicating the
Instances of Total Take as a Percentage of Abundance Within the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Abundance Instances of total
takes represent separate individuals, especially for ---------------------- take as percentage
disturbance) of abundance
------------------------------------------------------------- ---------------------
Level B harassment Level A Total takes MITT
Species --------------------------- harassment ---------------------- MITT study MITT
------------ MITT study area + MITT study
MITT study area transit study area +
Behavioral TTS study area + corridor area transit
disturbance PTS area transit corridor
corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dwarf sperm whale.............................. 1,353 7,146 50 8,502 8,549 25,594 27,395 33 31
Pygmy sperm whale.............................. 533 2,877 19 3,412 3,429 10,431 11,168 33 31
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
number in the Estimated Take of Marine Mammals section.
As discussed above, the majority of takes by Level B harassment by
behavioral disturbance of odontocetes, and thereby dwarf and pygmy
sperm whales, is expected to be in the form of low to occasionally
moderate severity of a generally shorter duration. As discussed earlier
in this section, we anticipate more severe effects from takes when
animals are exposed to higher received levels or for longer durations.
Occasional milder Level B harassment by behavioral disturbance, as is
expected here, is unlikely to cause long-term consequences for either
individual animals or populations, even if some smaller subset of the
takes are in the form of a longer (several hours or a day) and more
moderate response.
We note that dwarf and pygmy sperm whales, as HF-sensitive species,
have a lower PTS threshold than all other groups and therefore are
generally likely to experience larger amounts of TTS and PTS, and NMFS
accordingly has evaluated and authorized higher numbers. Also, however,
regarding PTS from sonar exposure, Kogia whales are still likely to
avoid sound levels that would cause higher levels of TTS (greater than
20 dB) or PTS. Therefore, even though the number of TTS and PTS takes
are higher than for other odontocetes, any PTS is expected to be at a
lower level and for all of the reasons described above, TTS and PTS
takes are not expected to impact reproduction or survival of any
individual.
Neither pygmy sperm whales nor dwarf sperm whales are listed under
the ESA, and there are no known biologically important areas identified
for these species in the MITT Study Area and Transit Corridor. There
have been no stock(s) specified for pygmy sperm whales and dwarf sperm
whales found in the MITT Study Area and Transit Corridor, and there is
no associated SAR. There is also no information on trends for these
species within the MITT Study Area. Both pygmy and dwarf sperm whales
will benefit from the procedural mitigation measures described earlier
in the Mitigation Measures section.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disruption), the number of estimated total instances of take
compared to the abundance is 33 percent for both dwarf and pygmy sperm
whales in the MITT Study Area and 31 percent in the MITT Study Area and
the transit corridor combined (Table 48). Regarding the severity of
those individual Level B harassment takes by behavioral disruption, we
have explained that the duration of any exposure is expected to be
between minutes and hours (i.e., relatively short) and the received
sound levels largely below 172 dB (i.e., of a lower, to occasionally
moderate, level
[[Page 46405]]
and less likely to evoke a severe response). Regarding the severity of
TTS takes, they are expected to be low-level, of short duration, and
mostly not in a frequency band that would be expected to interfere with
dwarf or pygmy sperm whale communication or other important low-
frequency cues. Therefore, the associated lost opportunities and
capabilities are not at a level that will impact reproduction or
survival. Dwarf sperm whales and pygmy sperm whales could be taken by a
small amount of PTS annually, of likely low severity as described
previously. A small permanent loss of hearing sensitivity (PTS) may
include some degree of energetic costs for compensating or may mean
some small loss of opportunities or detection capabilities, but at the
expected degree the estimated takes by Level A harassment takes by PTS
for dwarf sperm whales and pygmy sperm whales are unlikely to impact
behaviors, opportunities, or detection capabilities to a degree that
will interfere with reproductive success or survival of any
individuals, let alone affect annual rates of recruitment or survival.
Altogether, dwarf and pygmy sperm whales are not listed under the
ESA and there are no known population trends. Our analysis suggests
that fewer than half of the individuals in the MITT Study Area and
Transit Corridor will be taken, and disturbed at a low-moderate level,
with those individuals likely not disturbed on more than a few non-
sequential days a year. No mortality is anticipated or authorized. The
low magnitude and severity of harassment effects is not expected to
result in impacts on the reproduction or survival of any individuals,
let alone have impacts on annual rates of recruitment or survival,
therefore, the total take will not adversely affect this species
through impacts on annual rates of recruitment or survival. Some
individuals are estimated to be taken by PTS of likely low severity. A
small permanent loss of hearing sensitivity (PTS) may include some
degree of energetic costs for compensating or may mean some small loss
of opportunities or detection capabilities, but at the expected scale
the estimated takes by Level A harassment by PTS are unlikely to impact
behaviors, opportunities, or detection capabilities to a degree that
would interfere with reproductive success or survival of any
individuals, let alone affect annual rates of recruitment or survival.
For these reasons, we have determined, in consideration of all of the
effects of the Navy's activities combined, that the authorized take
will have a negligible impact on both dwarf and pygmy sperm whales.
Sperm whale--This section brings together the broader discussion
above with the discussion of the different types and amounts of take
that sperm whales could potentially incur, the applicable mitigation,
and the status of the species to support the negligible impact
determination.
In Table 49 below for sperm whales, we indicate the total annual
numbers of take by Level A and Level B harassment, and a number
indicating the instances of total take as a percentage of the abundance
within the MITT Study Area alone, as well as the MITT Study Area plus
the Transit Corridor, which was calculated separately. While the
density used to calculate take is the same for these two areas, the
takes were calculated separately for the two areas for sperm whales,
because the activity levels are higher in the MITT Study Area and it is
helpful to understand the comparative impacts in the two areas. Note
also that for sperm whales, the abundance within the MITT Study Area
and Transit Corridor represents only a portion of the species
abundance.
Table 49--Annual Estimated Takes by Level B Harassment and Level A Harassment for Sperm Whales and Number Indicating the Instances of Total Take as a
Percentage of Abundance Within the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Abundance Instances of total
takes represent separate individuals, especially for ---------------------- take as percentage
disturbance) of abundance
------------------------------------------------------------- ---------------------
Level B harassment Level A Total takes MITT
Species --------------------------- harassment ---------------------- MITT study MITT
------------ MITT study area + MITT study
MITT study area transit study area +
Behavioral TTS study area + corridor area transit
disturbance PTS area transit corridor
corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale.................................... 192 11 0 189 203 4,216 5,146 4 4
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
Study Area = Abundance in the MITT Study. Not that the total annual takes described here may be off by a digit due to rounding. This occurred here as
the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
number in the Estimated Take of Marine Mammals section.
As discussed above, the majority of takes by Level B harassment by
behavioral disturbance of odontocetes, and thereby sperm whales, is
expected to be in the form of low to moderate severity of a generally
shorter duration. As mentioned earlier in this section, we anticipate
more severe effects from takes when animals are exposed to higher
received levels or for longer durations. Occasional milder Level B
harassment by behavioral disturbance, as is expected here, is unlikely
to cause long-term consequences for either individual animals or
populations.
Sperm whales are listed as endangered under the ESA throughout
their range, but there is no ESA designated critical habitat, or known
biologically important areas identified for this species within the
MITT Study Area. There have been no stock(s) specified for sperm whales
found in the MITT Study Area and Transit Corridor, and there is no
associated SAR. There is also no information on trends for this species
within the MITT Study Area or in other parts of their range (NMFS
2019).
Sperm whales have been routinely sighted in the MITT Study Area and
detected in acoustic monitoring records. Sperm whales will benefit from
the procedural mitigation measures described earlier in the Mitigation
Measures section.
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disruption), the number of estimated total instances of take
compared to the abundance is 4 percent in the MITT Study Area and 4
percent in the MITT Study Area and transit corridor combined (Table
49). Regarding the severity of those individual takes by Level B
harassment by behavioral disturbance, we have explained that the
[[Page 46406]]
duration of any exposure is expected to be between minutes and hours
(i.e., relatively short) and the received sound levels largely below
172 dB (i.e., of a lower, to occasionally moderate level and less
likely to evoke a severe response). Regarding the severity of TTS
takes, they are expected to be low-level, of short duration, and mostly
not in a frequency band that would be expected to interfere with
important low-frequency cues. While the narrowband/single frequency
threshold shift incurred may overlap with parts of the frequency range
that sperm whales use for communication, any associated lost
opportunities and capabilities would not be at a level that will impact
reproduction or survival.
Altogether, sperm whales are listed as endangered under the ESA and
there are no known population trends. Our analysis suggests that a very
small portion of the individuals within the MITT Study Area and Transit
Corridor will be taken and disturbed at a low-moderate level, with
those individuals disturbed on likely one day within a year. No
mortality or Level A harassment is anticipated or authorized. This low
magnitude and severity of harassment effects is not expected to result
in impacts on the reproduction or survival of any individuals, let
alone have impacts on annual rates of recruitment or survival, and
therefore the total take will not adversely affect this species through
impacts on annual rates of recruitment or survival. For these reasons,
we have determined, in consideration of all of the effects of the
Navy's activities combined, that the authorized take will have a
negligible impact on sperm whales.
Beaked Whales--This section builds on the broader odontocete
discussion above (i.e., that information applies to beaked whales as
well), except where we offer alternative information about the received
levels for beaked whale for Level B harassment by behavioral
disturbance, and brings together the discussion of the different types
and amounts of take that different beaked whale species will incur, the
applicable mitigation, and the status of each species to support the
negligible impact determination for each species. For beaked whales,
there is no Level A harassment or mortality anticipated or authorized.
In Table 50 below for beaked whales, we indicate the total annual
numbers of take by Level A and Level B harassment for the four species,
and a number indicating the instances of total take as a percentage of
the abundance in the MITT Study Area alone, as well as the MITT Study
Area plus the Transit Corridor, which was calculated separately. While
the density used to calculate take is the same for these two areas, the
takes were calculated separately for the two areas for beaked whales,
because the activity levels are higher in the MITT Study Area and it is
helpful to understand the comparative impacts in the two areas. Note
also that for beaked whales, the abundance within the MITT Study Area
and Transit Corridor represents only a portion of the species
abundance.
Table 50--Annual Estimated Takes by Level B Harassment and Level A Harassment for Beaked Whales and Number Indicating the Instances of Total Take as a
Percentage of Abundance in the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Abundance Instances of total
takes represent separate individuals, especially for ---------------------- take as percentage
disturbance) of abundance
------------------------------------------------------------- ---------------------
Level B harassment Level A Total takes MITT
Species --------------------------- harassment ---------------------- MITT study MITT
------------ MITT study area + MITT study
MITT study area transit study area +
Behavioral TTS study area + corridor area transit
disturbance PTS area transit corridor
corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale...................... 1,691 27 0 1,698 1,718 3,083 3,376 55 51
Cuvier's beaked whale.......................... 642 4 0 534 646 1,075 2,642 50 24
Ginkgo-toothed beaked whale.................... 3,660 66 0 3,662 3,726 6,775 7,567 54 49
Longman's beaked whale......................... 5,959 107 0 6,056 6,066 11,148 11,253 54 54
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
number in the Estimated Take of Marine Mammals section.
As discussed above, the majority of takes by Level B harassment by
behavioral disturbance of odontocetes, and thereby beaked whales, is
expected to be in the form of low to moderate severity of a generally
shorter duration. The majority of takes by harassment of beaked whales
in the MITT Study Area are caused by sources from the MFAS active sonar
bin (which includes hull-mounted sonar) because they are high level
narrowband sources that fall within the 1-10 kHz range, which overlap a
more sensitive portion (though not the most sensitive) of the MF
hearing range. Also, of the sources expected to result in take, they
are used in a large portion of exercises (see Table 3). Most of the
takes (96 percent) from the MF1 bin in the MITT Study Area would result
from received levels between 148 and 160 dB SPL. For the remaining
active sonar bin types, the percentages are as follows: LF4 = 99
percent between 124 and 136 dB SPL, MF4 = 98 percent between 130 and
148 dB SPL, MF5 = 97 percent between 100 and 142 dB SPL, and HF4 = 95
percent between 100 and 148 dB SPL. Given the levels they are exposed
to and their sensitivity, some responses would be of a lower severity,
but many would likely be considered moderate.
Research has shown that beaked whales are especially sensitive to
the presence of human activity (Pirotta et al., 2012; Tyack et al.,
2011) and therefore have been assigned a lower harassment threshold,
with lower received levels resulting in a higher percentage of
individuals being harassed and a more distant distance cutoff (50 km
for high source level, 25 km for moderate source level). Beaked whales
have also been found to respond to naval sonar, in certain
circumstances, in a manner that can lead to stranding and in a few
cases, globally, beaked whale strandings have been causally associated
with active sonar operation. However, as discussed in the Stranding
section of the Potential Effects of Specified Activities on Marine
Mammals and Their Habitat section,
[[Page 46407]]
NMFS has determined that the activities included in this 7-year rule
are not reasonably likely to result in the mortality of beaked whales.
Beaked whales have been documented to exhibit avoidance of human
activity or respond to vessel presence (Pirotta et al., 2012). Beaked
whales were observed to react negatively to survey vessels or low
altitude aircraft by quick diving and other avoidance maneuvers, and
none were observed to approach vessels (Wursig et al., 1998). Research
and observations show that if beaked whales are exposed to sonar or
other active acoustic sources, they may startle, break off feeding
dives, and avoid the area of the sound source to levels of 157 dB re 1
[micro]Pa, or below (McCarthy et al., 2011). Acoustic monitoring during
actual sonar exercises revealed some beaked whales continuing to forage
at levels up to 157 dB re 1 [micro]Pa (Tyack et al., 2011). Stimpert et
al. (2014) tagged a Baird's beaked whale, which was subsequently
exposed to simulated MFAS. Changes in the animal's dive behavior and
locomotion were observed when received level reached 127 dB re 1
[micro]Pa. However, Manzano-Roth et al. (2013) found that for beaked
whale dives that continued to occur during MFAS activity, differences
from normal dive profiles and click rates were not detected with
estimated received levels up to 137 dB re 1 [micro]Pa while the animals
were at depth during their dives. In research done at the Navy's fixed
tracking range in the Bahamas, animals were observed to leave the
immediate area of the anti-submarine warfare training exercise
(avoiding the sonar acoustic footprint at a distance where the received
level was ``around 140 dB SPL'', according to Tyack et al. (2011)), but
return within a few days after the event ended (Claridge and Durban,
2009; McCarthy et al., 2011; Moretti et al., 2009, 2010; Tyack et al.,
2010, 2011). Tyack et al. (2011) report that, in reaction to sonar
playbacks, most beaked whales stopped echolocating, made long slow
ascent to the surface, and moved away from the sound. A similar
behavioral response study conducted in Southern California waters
during the 2010-2011 field season found that Cuvier's beaked whales
exposed to MFAS displayed behavior ranging from initial orientation
changes to avoidance responses characterized by energetic fluking and
swimming away from the source (DeRuiter et al., 2013b). However, the
authors did not detect similar responses to incidental exposure to
distant naval sonar exercises at comparable received levels, indicating
that context of the exposures (e.g., source proximity, controlled
source ramp-up) may have been a significant factor. The study itself
found the results inconclusive and meriting further investigation.
Cuvier's beaked whale responses suggested particular sensitivity to
sound exposure consistent with results for Blainville's beaked whale.
Populations of beaked whales and other odontocetes in the Bahamas
and other Navy fixed ranges that have been operating for decades appear
to be stable. Behavioral reactions (avoidance of the area of Navy
activity) seem likely in most cases if beaked whales are exposed to
anti-submarine sonar within a few tens of kilometers, especially for
prolonged periods (a few hours or more) since this is one of the most
sensitive marine mammal groups to anthropogenic sound of any species or
group studied to date and research indicates beaked whales will leave
an area where anthropogenic sound is present (De Ruiter et al., 2013;
Manzano-Roth et al., 2013; Moretti et al., 2014; Tyack et al., 2011).
Research involving tagged Cuvier's beaked whales in the SOCAL Range
Complex reported on by Falcone and Schorr (2012, 2014) indicates year-
round prolonged use of the Navy's training and testing area by these
beaked whales and has documented movements in excess of hundreds of
kilometers by some of those animals. Given that some of these animals
may routinely move hundreds of kilometers as part of their normal
pattern, leaving an area where sonar or other anthropogenic sound is
present may have little, if any, cost to such an animal. Photo
identification studies in the SOCAL Range Complex, a Navy range that is
utilized for training and testing, have identified approximately 100
Cuvier's beaked whale individuals with 40 percent having been seen in
one or more prior years, with re-sightings up to seven years apart
(Falcone and Schorr, 2014). These results indicate long-term residency
by individuals in an intensively used Navy training and testing area,
which may also suggest a lack of long-term consequences as a result of
exposure to Navy training and testing activities. More than eight years
of passive acoustic monitoring on the Navy's instrumented range west of
San Clemente Island documented no significant changes in annual and
monthly beaked whale echolocation clicks, with the exception of
repeated fall declines likely driven by natural beaked whale life
history functions (DiMarzio et al., 2018). Finally, results from
passive acoustic monitoring estimated that regional Cuvier's beaked
whale densities were higher than indicated by NMFS' broad scale visual
surveys for the U.S. West Coast (Hildebrand and McDonald, 2009).
These beaked whale species are not listed as endangered or
threatened species under the ESA, and there are no known biologically
important areas identified for these species in the MITT Study Area.
There have been no stock(s) specified for beaked whales found in the
MITT Study Area and Transit Corridor, and there are no associated SARs.
There is also no information on trends for these species within the
MITT Study Area. All of the beaked whales species discussed in this
section will benefit from the procedural mitigation measures described
earlier in the Mitigation Measures section.
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disturbance), the number of estimated instances of take
compared to the abundance is 50 to 55 percent in the MITT Study Area
and 24 to 54 percent in the MITT Study Area and transit corridor
combined (Table 50). Regarding the severity of those individual takes
by Level B harassment by behavioral disturbance, we have explained that
the duration of any exposure is expected to be between minutes and
hours (i.e., relatively short) and the received sound levels largely
below 160 dB, though with beaked whales, which are considered somewhat
more sensitive, this could mean that some individuals will leave
preferred habitat for a day (i.e., moderate level takes). However,
while interrupted feeding bouts are a known response and concern for
odontocetes, we also know that there are often viable alternative
habitat options nearby. Regarding the severity of takes by TTS, they
are expected to be low-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with beaked whale
communication or other important low-frequency cues. Therefore, the
associated lost opportunities and capabilities are not at a level that
will impact reproduction or survival. As mentioned earlier in the
odontocete overview, we anticipate more severe effects from takes when
animals are exposed to higher received levels or sequential days of
impacts.
Altogether, none of the four beaked whale species are listed under
the ESA and there are no known population trends. Our analysis suggests
that fewer than half of the individuals of each species in the MITT
Study Area and Transit Corridor will be taken and disturbed at a low or
moderate level, with those individuals likely not
[[Page 46408]]
disturbed on more than a few non-sequential days a year. No mortality
or Level A harassment is anticipated or authorized. This low magnitude
and low to moderate severity of harassment effects is not expected to
result in impacts on individual reproduction or survival, let alone
have impacts on annual rates of recruitment or survival and, therefore,
the total take will not adversely affect this species through impacts
on annual rates of recruitment or survival. For these reasons, we have
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take will have a negligible
impact on these four beaked whale species.
Small Whales and Dolphins--This section builds on the broader
discussion above and brings together the discussion of the different
types and amounts of take that different small whale and dolphin
species are likely to incur, the applicable mitigation, and the status
of the species to support the negligible impact determinations for each
species.
In Table 51 below for dolphins and small whales, we indicate for
each species the total annual numbers of take by Level A and Level B
harassment, and a number indicating the instances of total take as a
percentage of abundance in the MITT Study Area alone, as well as the
MITT Study Area plus the Transit Corridor, which was calculated
separately. While the density used to calculate take is the same for
these two areas, the takes were calculated separately for the two areas
for dolphins and small whales, because the activity levels are higher
in the MITT Study Area and it is helpful to understand the comparative
impacts in the two areas. Note also that for dolphins and small whales,
the abundance within the MITT Study Area and Transit Corridor
represents only a portion of the species abundance.
Table 51--Annual Estimated Takes by Level B Harassment and Level A Harassment for Dolphins and Small Whales and Number Indicating the Instances of Total
Take as a Percentage of Abundance in the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Abundance Instances of total
takes represent separate individuals, especially for ---------------------- take as percentage
disturbance) of abundance
------------------------------------------------------------- ---------------------
Level B harassment Level A Total takes MITT
Species --------------------------- harassment ---------------------- MITT study MITT
------------ MITT study area + MITT study
MITT study area transit study area +
Behavioral TTS study area + corridor area transit
disturbance PTS area transit corridor
corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin............................. 116 21 0 132 137 753 1,076 17 13
False killer whale............................. 641 121 0 759 762 3,979 4,218 19 18
Fraser's dolphin............................... 11,326 1,952 1 13,261 13,279 75,420 76,476 18 17
Killer whale................................... 36 8 0 44 44 215 253 20 17
Melon-headed whale............................. 2,306 509 0 2,798 2,815 15,432 16,551 18 17
Pantropical spotted dolphin.................... 12,078 2,818 1 14,820 14,897 81,013 85,755 18 17
Pygmy killer whale............................. 87 17 0 103 104 502 527 21 20
Risso's dolphin................................ 2,650 520 0 3,166 3,170 16,991 17,184 19 18
Rough-toothed dolphin.......................... 161 36 0 185 197 1,040 1,815 18 11
Short-finned pilot whale....................... 987 176 0 1,150 1,163 5,700 6,583 20 18
Spinner dolphin................................ 1,185 229 1 1,404 1,415 4,449 5,232 32 27
Striped dolphin................................ 3,256 751 0 3,956 4,007 22,081 24,528 18 16
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
number in the Estimated Take of Marine Mammals section.
As discussed above, the majority of takes by Level B harassment by
behavioral disturbance of odontocetes, and thereby dolphins and small
whales, from hull-mounted sonar (MFAS) in the MITT Study Area would
result from received levels between 154 and 172 dB SPL. Therefore, the
majority of takes by Level B harassment are expected to be in the form
of low to occasionally moderate severity of a generally shorter
duration. As mentioned earlier in this section, we anticipate more
severe effects from takes when animals are exposed to higher received
levels or for longer durations. Occasional milder Level B harassment by
behavioral disturbance, as is expected here, is unlikely to cause long-
term consequences for either individual animals or populations that
have any effect on reproduction or survival. One Level A harassment is
anticipated and authorized for three species (Fraser's dolphin,
pantropical spotted dolphin, and spinner dolphin).
Research and observations show that if delphinids are exposed to
sonar or other active acoustic sources they may react in a number of
ways depending on their experience with the sound source and what
activity they are engaged in at the time of the acoustic exposure.
Delphinids may not react at all until the sound source is approaching
within a few hundred meters to within a few kilometers depending on the
environmental conditions and species. Some dolphin species (the more
surface-dwelling taxa--typically those with ``dolphin'' in the common
name, such as bottlenose dolphins, spotted dolphins, spinner dolphins,
rough-toothed dolphins, etc., but not Risso's dolphin), especially
those residing in more industrialized or busy areas, have demonstrated
more tolerance for disturbance and loud sounds and many of these
species are known to approach vessels to bow-ride. These species are
often considered generally less sensitive to disturbance. Dolphins and
small whales that reside in deeper waters and generally have fewer
interactions with human activities are more likely to demonstrate more
typical avoidance reactions and foraging interruptions as described
above in the odontocete overview.
All the dolphin and small whale species discussed in this section
will benefit from the procedural mitigation measures described earlier
in the Mitigation Measures section. Additionally, the Agat Bay
Nearshore Geographic Mitigation Area will provide protection for
spinner dolphins as the Navy will not use in-water explosives or
[[Page 46409]]
MF1 ship hull-mounted mid-frequency active sonar in this area. High use
areas for spinner dolphins including Agat Bay are where animals
congregate during the day to rest (Amesbury et al., 2001; Eldredge,
1991). Behavioral disruptions during resting periods can adversely
impact health and energetic budgets by not allowing animals to get the
needed rest and/or by creating the need to travel and expend additional
energy to find other suitable resting areas. Avoiding sonar and
explosives in this area reduces the likelihood of impacts that would
affect reproduction and survival.
None of the small whale and dolphin species are listed as
endangered or threatened species under the ESA. As noted above, an
important resting area has been identified for spinner dolphins, and
mitigation has been included to reduce impacts in the area. There have
been no stock(s) specified for small whales and dolphins found in the
MITT Study Area and Transit Corridor, and there are no associated SARs.
There is also no information on trends for these species within the
MITT Study Area.
Regarding the magnitude of takes by Level B harassment (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance is 32 percent for spinner dolphins and
17 to 21 percent for the remaining dolphins and small whales in the
MITT Study Area. The number of estimated total instances of take
compared to the abundance is 27 percent for spinner dolphins and 20
percent or less for the remaining dolphins and small whales in the MITT
Study and transit corridor combined (Table 51).
Regarding the severity of those individual takes by Level B
harassment by behavioral disturbance, we have explained the duration of
any exposure is expected to be between minutes and hours (i.e.,
relatively short) and the received sound levels largely below 172 dB
(i.e., of a lower, to occasionally moderate, level and less likely to
evoke a severe response). Regarding the severity of takes by TTS, they
are expected to be low-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with communication
or other important low-frequency cues. The associated lost
opportunities and capabilities are not at a level that will impact
reproduction or survival. One individual each of three species (spinner
dolphin, Fraser's dolphin, and pantropical spotted dolphin) is
estimated to be taken by one PTS annually, of likely low severity as
described previously. A small permanent loss of hearing sensitivity
(PTS) may include some degree of energetic costs for compensating or
may mean some small loss of opportunities or detection capabilities,
but at the expected scale the estimated takes by Level A harassment by
PTS for spinner dolphin, Fraser's dolphin, and pantropical spotted
dolphin are unlikely to impact behaviors, opportunities, or detection
capabilities to a degree that will interfere with reproductive success
or survival of any individuals, let alone affect annual rates of
recruitment or survival.
Altogether, none of the small whale or dolphin species are listed
under the ESA and there are no known population trends. Our analysis
suggests that only a small portion of the individuals of any of these
species in the MITT Study Area or Transit Corridor will be taken and
disturbed at a low-moderate level, with those individuals likely
disturbed no more than a few non-sequential days a year. One take by
PTS for three dolphin species is anticipated and authorized, but at the
expected scale the estimated take by Level A harassment by PTS is
unlikely to impact behaviors, opportunities, or detection capabilities
to a degree that would interfere with reproductive success or survival
of any individuals, let alone annual rates of recruitment or survival.
This low magnitude and severity of harassment effects is not expected
to result in impacts on the reproduction or survival of any
individuals, let alone have impacts on annual rates of recruitment or
survival and, therefore, the total take will not adversely affect these
species through impacts on annual rates of recruitment or survival. For
these reasons, we have determined, in consideration of all of the
effects of the Navy's activities combined, that the authorized take
will have a negligible impact on all twelve of these species of small
whales and dolphins.
Determination
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
Specified Activities will have a negligible impact on all affected
marine mammal species.
Subsistence Harvest of Marine Mammals
There are no subsistence uses or harvest of marine mammals in the
geographic area affected by the specified activities. Therefore, NMFS
has determined that the total taking affecting species will not have an
unmitigable adverse impact on the availability of the species for
taking for subsistence purposes.
Classification
Endangered Species Act
There are five marine mammal species under NMFS jurisdiction that
are listed as endangered or threatened under the ESA with confirmed or
possible occurrence in the MITT Study Area: Blue whale, fin whale,
humpback whale, sei whale, and sperm whale. There is no ESA-designated
critical habitat for any species in the MITT Study Area. The Navy
consulted with NMFS pursuant to section 7 of the ESA for MITT
activities, and NMFS also consulted internally on the issuance of these
regulations and LOA under section 101(a)(5)(A) of the MMPA. NMFS issued
a Biological Opinion concluding that the issuance of the rule and
subsequent LOA is not likely to jeopardize the continued existence of
the threatened and endangered species under NMFS' jurisdiction and is
not likely to result in the destruction or adverse modification of
critical habitat in the MITT Study Area. The Biological Opinion for
this action is available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
National Marine Sanctuaries Act
There are no national marine sanctuaries in the MITT Study Area.
Therefore, no consultation under the National Marine Sanctuaries Act is
required.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate its proposed actions and alternatives with respect
to potential impacts on the human environment. NMFS participated as a
cooperating agency on the 2020 MITT FSEIS/OEIS, which was published on
June 5, 2020, and is available at http://www.MITT-eis.com. In
accordance with 40 CFR 1506.3, NMFS independently reviewed and
evaluated the 2020 MITT FSEIS/OEIS and determined that it is adequate
and sufficient to meet our responsibilities under NEPA for the issuance
of this rule and associated LOA. NOAA therefore adopted the 2020 MITT
FSEIS/OEIS. NMFS has prepared a separate Record of Decision. NMFS'
Record of Decision for adoption of the 2020 MITT FSEIS/OEIS
[[Page 46410]]
and issuance of this final rule and subsequent LOA can be found at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
Executive Order 12866
The Office of Management and Budget has determined that this rule
is not significant for purposes of Executive Order 12866.
Regulatory Flexibility Act
Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel
for Regulation of the Department of Commerce certified to the Chief
Counsel for Advocacy of the Small Business Administration during the
proposed rule stage that this action would not have a significant
economic impact on a substantial number of small entities. The factual
basis for the certification was published in the proposed rule and is
not repeated here. No comments were received regarding this
certification. As a result, a regulatory flexibility analysis was not
required and none was prepared.
Waiver of Delay in Effective Date
NMFS has determined that there is good cause under the
Administrative Procedure Act (5 U.S.C. 553(d)(3)) to waive the 30-day
delay in the effective date of this final rule. No individual or entity
other than the Navy is affected by the provisions of these regulations.
The Navy has requested that this final rule take effect on or before
July 31, 2020, to accommodate the Navy's LOA expiring on August 3,
2020, so as to not cause a disruption in training and testing
activities. NMFS was unable to accommodate the 30-day delay of
effectiveness period due to the need to consider new information that
became available in June 2020, as well as a revised humpback whale
analysis that arose through the ESA section 7 consultation. The waiver
of the 30-day delay of the effective date of the final rule will ensure
that the MMPA final rule and LOA are in place by the time the previous
authorizations expire. Any delay in finalizing the rule would result in
either: (1) A suspension of planned naval training and testing, which
would disrupt vital training and testing essential to national
security; or (2) the Navy's procedural non-compliance with the MMPA
(should the Navy conduct training and testing without an LOA), thereby
resulting in the potential for unauthorized takes of marine mammals.
Moreover, the Navy is ready to implement the regulations immediately.
For these reasons, NMFS finds good cause to waive the 30-day delay in
the effective date. In addition, the rule authorizes incidental take of
marine mammals that would otherwise be prohibited under the statute.
Therefore, by granting an exception to the Navy, the rule will relieve
restrictions under the MMPA, which provides a separate basis for
waiving the 30-day effective date for the rule.
List of Subjects in 50 CFR Part 218
Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine
mammals, Navy, Penalties, Reporting and recordkeeping requirements,
Seafood, Sonar, Transportation.
Dated: July 15, 2020.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For reasons set forth in the preamble, 50 CFR part 218 is amended
as follows:
PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
0
1. The authority citation for part 218 continues to read as follows:
Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.
0
2. Revise subpart J to read as follows:
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Mariana
Islands Training and Testing (MITT)
Sec.
218.90 Specified activity and geographical region.
218.91 Effective dates.
218.92 Permissible methods of taking.
218.93 Prohibitions.
218.94 Mitigation requirements.
218.95 Requirements for monitoring and reporting.
218.96 Letters of Authorization.
218.97 Renewals and modifications of Letters of Authorization.
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Mariana
Islands Training and Testing (MITT)
Sec. 218.90 Specified activity and geographical region.
(a) Regulations in this subpart apply only to the U.S. Navy for the
taking of marine mammals that occurs in the area described in paragraph
(b) of this section and that occurs incidental to the activities listed
in paragraph (c) of this section.
(b) The taking of marine mammals by the Navy under this subpart may
be authorized in a Letter of Authorization (LOA) only if it occurs
within the Mariana Islands Training and Testing (MITT) Study Area. The
MITT Study Area is comprised of three components: The Mariana Islands
Range Complex (MIRC), additional areas on the high seas, and a transit
corridor between the MIRC and the Hawaii Range Complex (HRC). The MIRC
includes the waters south of Guam to north of Pagan (Commonwealth of
the Northern Mariana Islands (CNMI)), and from the Pacific Ocean east
of the Mariana Islands to the Philippine Sea to the west, encompassing
501,873 square nautical miles (nmi\2\) of open ocean. The additional
areas of the high seas include the area to the north of the MIRC that
is within the U.S. Exclusive Economic Zone (EEZ) of the CNMI and the
areas to the west of the MIRC. The transit corridor is outside the
geographic boundaries of the MIRC and represents a great circle route
(i.e., the shortest distance) across the high seas for Navy ships
transiting between the MIRC and the HRC. Additionally, the MITT Study
Area includes pierside locations in the Apra Harbor Naval Complex.
(c) The taking of marine mammals by the Navy is only authorized if
it occurs incidental to the Navy conducting training and testing
activities, including:
(1) Training. (i) Amphibious warfare;
(ii) Anti-submarine warfare;
(iii) Mine warfare;
(vi) Surface warfare; and
(vii) Other training activities.
(2) Testing. (i) Naval Air Systems Command Testing Activities;
(ii) Naval Sea Systems Command Testing Activities; and
(iii) Office of Naval Research Testing Activities.
Sec. 218.91 Effective dates.
Regulations in this subpart are effective from July 31, 2020, to
July 30, 2027.
Sec. 218.92 Permissible methods of taking.
(a) Under an LOA issued pursuant to Sec. Sec. 216.106 of this
section and 218.96, the Holder of the LOA (hereinafter ``Navy'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 218.90(b) by Level A harassment and Level B
harassment associated with the use of active sonar and other acoustic
sources and explosives, provided the activity is in compliance with all
terms, conditions, and requirements of the regulations in this subpart
and the applicable LOA.
(b) The incidental take of marine mammals by the activities listed
in Sec. 218.90(c) is limited to the species listed in Table 1 of this
section.
[[Page 46411]]
Table 1 to Sec. 218.92(b)
------------------------------------------------------------------------
Species Scientific name
------------------------------------------------------------------------
Blue whale................................ Balaenoptera musculus.
Bryde's whale............................. Balaenoptera edeni.
Fin whale................................. Balaenoptera physalus.
Humpback whale............................ Megaptera novaeangliae.
Minke whale............................... Balaenoptera acutorostrata.
Omura's whale............................. Balaenoptera omurai.
Sei whale................................. Balaenoptera borealis.
Blainville's beaked whale................. Mesoplodon densirostris.
Common bottlenose dolphin................. Tursiops truncatus.
Cuvier's beaked whale..................... Ziphius cavirostris.
Dwarf sperm whale......................... Kogia sima.
False killer whale........................ Pseudorca crassidens.
Fraser's dolphin.......................... Lagenodelphis hosei.
Ginkgo-toothed beaked whale............... Mesoplodon ginkgodens.
Killer whale.............................. Orcinus orca.
Longman's beaked whale.................... Indopacetus pacificus.
Melon-headed whale........................ Peponocephala electra.
Pantropical spotted dolphin............... Stenella attenuata.
Pygmy killer whale........................ Feresa attenuata.
Pygmy sperm whale......................... Kogia breviceps.
Risso's dolphin........................... Grampus griseus.
Rough-toothed dolphin..................... Steno bredanensis.
Short-finned pilot whale.................. Globicephala macrorhynchus.
Sperm whale............................... Physeter macrocephalus.
Spinner dolphin........................... Stenella longirostris.
Striped dolphin........................... Stenella coeruleoalba.
------------------------------------------------------------------------
Sec. 218.93 Prohibitions.
Notwithstanding incidental takings contemplated in Sec. 218.92(a)
and authorized by an LOA issued under Sec. Sec. 216.106 of this
section and 218.96, no person in connection with the activities listed
in Sec. 218.90(c) may:
(a) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or an LOA issued under Sec. Sec. 216.106
of this section and 218.96;
(b) Take any marine mammal not specified in Sec. 218.92(b);
(c) Take any marine mammal specified in Sec. 218.92(b) in any
manner other than as specified in the LOA issued under Sec. Sec.
216.106 of this chapter and 218.96; or
(d) Take a marine mammal specified in Sec. 218.92(b) if NMFS
determines such taking results in more than a negligible impact on the
species of such marine mammal.
Sec. 218.94 Mitigation requirements.
When conducting the activities identified in Sec. 218.90(c), the
mitigation measures contained in any LOA issued under Sec. Sec.
216.106 of this section and 218.96 must be implemented. These
mitigation measures include, but are not limited to:
(a) Procedural mitigation. Procedural mitigation is mitigation that
the Navy must implement whenever and wherever an applicable training or
testing activity takes place within the MITT Study Area for each
applicable activity category or stressor category and includes acoustic
stressors (i.e., active sonar and other transducers, weapons firing
noise), explosive stressors (i.e., sonobuoys, torpedoes, medium-caliber
and large-caliber projectiles, missiles and rockets, bombs, sinking
exercises, mines, anti-swimmer grenades), and physical disturbance and
strike stressors (i.e., vessel movement; towed in-water devices; small-
, medium-, and large-caliber non-explosive practice munitions; non-
explosive missiles and rockets; and non-explosive bombs and mine
shapes).
(1) Environmental awareness and education. Appropriate Navy
personnel (including civilian personnel) involved in mitigation and
training or testing reporting under the specified activities will
complete one or more modules of the U.S. Navy Afloat Environmental
Compliance Training Series, as identified in their career path training
plan. Modules include: Introduction to the U.S. Navy Afloat
Environmental Compliance Training Series, Marine Species Awareness
Training; U.S. Navy Protective Measures Assessment Protocol; and U.S.
Navy Sonar Positional Reporting System and Marine Mammal Incident
Reporting.
(2) Active sonar. Active sonar includes low-frequency active sonar,
mid-frequency active sonar, and high-frequency active sonar. For
vessel-based activities, mitigation applies only to sources that are
positively controlled and deployed from manned surface vessels (e.g.,
sonar sources towed from manned surface platforms). For aircraft-based
activities, mitigation applies only to sources that are positively
controlled and deployed from manned aircraft that do not operate at
high altitudes (e.g., rotary-wing aircraft). Mitigation does not apply
to active sonar sources deployed from unmanned aircraft or aircraft
operating at high altitudes (e.g., maritime patrol aircraft).
(i) Number of Lookouts and observation platform--(A) Hull-mounted
sources. One Lookout must be positioned for platforms with space or
manning restrictions while underway (at the forward part of a small
boat or ship) and platforms using active sonar while moored or at
anchor (including pierside); and two Lookouts must be positioned for
platforms without space or manning restrictions while underway (at the
forward part of the ship).
(B) Sources that are not hull-mounted sources. One Lookout must be
positioned on the ship or aircraft conducting the activity.
(ii) Mitigation zone and requirements. The mitigation zones must be
the zones as described in paragraphs (a)(2)(ii)(B) and (C) of this
section.
(A) Prior to the initial start of the activity (e.g., when
maneuvering on station), Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must relocate or delay the start of active sonar transmission.
(B) During the activity for low-frequency active sonar at or above
200 dB and hull-mounted mid-frequency active sonar, Navy personnel must
observe the mitigation zone for marine mammals and power down active
sonar transmission by 6 dB if marine mammals are observed within 1,000
yd of the sonar source; power down by an additional 4 dB (for a total
of 10 dB) if marine mammals are observed within 500 yd of the sonar
source; and cease transmission if marine mammals are observed within
200 yd of the sonar source.
(C) During the activity for low-frequency active sonar below 200
dB, mid-frequency active sonar sources that are not hull mounted, and
high-frequency active sonar, Navy personnel must observe the mitigation
zone for marine mammals and cease active sonar transmission if marine
mammals are observed within 200 yd of the sonar source.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing or powering up active sonar transmission) until
one of the following conditions has been met: The animal is observed
exiting the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the sonar source; the mitigation zone has been
clear from any additional sightings for 10 minutes (min) for aircraft-
deployed sonar sources or 30 min for vessel-deployed sonar sources; for
mobile activities, the active sonar
[[Page 46412]]
source has transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting; or for activities
using hull-mounted sonar where a dolphin(s) is observed in the
mitigation zone, the Lookout concludes that the dolphin(s) is
deliberately closing in on the ship to ride the ship's bow wave, and is
therefore out of the main transmission axis of the sonar (and there are
no other marine mammal sightings within the mitigation zone).
(3) Weapons firing noise. Weapons firing noise associated with
large-caliber gunnery activities.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned on the ship conducting the firing. Depending on the
activity, the Lookout could be the same as the one provided for under
``Explosive medium-caliber and large-caliber projectiles'' or under
``Small-, medium-, and large-caliber non-explosive practice munitions''
in paragraphs (a)(6)(i) and (a)(15)(i) of this section.
(ii) Mitigation zone and requirements. The mitigation zone must be
thirty degrees on either side of the firing line out to 70 yd from the
muzzle of the weapon being fired.
(A) Prior to the initial start of the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must relocate or delay the start of weapons
firing.
(B) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease weapons firing.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing weapons firing) until one of the following
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
firing ship; the mitigation zone has been clear from any additional
sightings for 30 min; or for mobile activities, the firing ship has
transited a distance equal to double that of the mitigation zone size
beyond the location of the last sighting.
(4) Explosive sonobuoys--(i) Number of Lookouts and observation
platform. One Lookout must be positioned in an aircraft or on a small
boat. If additional platforms are participating in the activity, Navy
personnel positioned on those assets (e.g., safety observers,
evaluators) must support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 600 yd around an explosive sonobuoy.
(B) Prior to the initial start of the activity (e.g., during
deployment of a sonobuoy pattern, which typically lasts 20-30 min),
Navy personnel must conduct passive acoustic monitoring for marine
mammals and use information from detections to assist visual
observations. Navy personnel also must visually observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must relocate or delay the start of sonobuoy or source/receiver pair
detonations.
(C) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease sonobuoy or source/receiver pair detonations.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing detonations) until one of the following conditions
has been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
sonobuoy; or the mitigation zone has been clear from any additional
sightings for 10 min when the activity involves aircraft that have fuel
constraints (e.g., helicopter), or 30 min when the activity involves
aircraft that are not typically fuel constrained.
(E) After completion of the activity (e.g., prior to maneuvering
off station), when practical (e.g., when platforms are not constrained
by fuel restrictions or mission-essential follow-on commitments), Navy
personnel must observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel on these assets must assist
in the visual observation of the area where detonations occurred.
(5) Explosive torpedoes--(i) Number of Lookouts and observation
platform. One Lookout must be positioned in an aircraft. If additional
platforms are participating in the activity, Navy personnel positioned
on those assets (e.g., safety observers, evaluators) must support
observing the mitigation zone for marine mammals and other applicable
biological resources while performing their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 2,100 yd around the intended impact location.
(B) Prior to the initial start of the activity (e.g., during
deployment of the target), Navy personnel must conduct passive acoustic
monitoring for marine mammals and use the information from detections
to assist visual observations. Navy personnel also must visually
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must relocate or delay the start of firing.
(C) During the activity, Navy personnel must observe the mitigation
zone for marine mammals. If marine mammals are observed, Navy personnel
must cease firing.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
intended impact location; or the mitigation zone has been clear from
any additional sightings for 10 min when the activity involves aircraft
that have fuel constraints, or 30 min when the activity involves
aircraft that are not typically fuel constrained.
(E) After completion of the activity (e.g., prior to maneuvering
off station), Navy personnel must when practical (e.g., when platforms
are not constrained by fuel restrictions or mission-essential follow-on
commitments), observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel on these assets must assist
in the visual observation of the area where detonations occurred.
[[Page 46413]]
(6) Explosive medium-caliber and large-caliber projectiles. Gunnery
activities using explosive medium-caliber and large-caliber
projectiles. Mitigation applies to activities using a surface target.
(i) Number of Lookouts and observation platform. One Lookout must
be on the vessel or aircraft conducting the activity. For activities
using explosive large-caliber projectiles, depending on the activity,
the Lookout could be the same as the one described in ``Weapons firing
noise'' in paragraph (a)(3)(i) of this section. If additional platforms
are participating in the activity, Navy personnel positioned on those
assets (e.g., safety observers, evaluators) must support observing the
mitigation zone for marine mammals and other applicable biological
resources while performing their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 200 yd around the intended impact location for air-to-surface
activities using explosive medium-caliber projectiles.
(B) The mitigation zone must be 600 yd around the intended impact
location for surface-to-surface activities using explosive medium-
caliber projectiles.
(C) The mitigation zone must be 1,000 yd around the intended impact
location for surface-to-surface activities using explosive large-
caliber projectiles.
(D) Prior to the initial start of the activity (e.g., when
maneuvering on station), Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must relocate or delay the start of firing.
(E) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease firing.
(F) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
intended impact location; the mitigation zone has been clear from any
additional sightings for 10 min for aircraft-based firing or 30 min for
vessel-based firing; or for activities using mobile targets, the
intended impact location has transited a distance equal to double that
of the mitigation zone size beyond the location of the last sighting.
(G) After completion of the activity (e.g., prior to maneuvering
off station), Navy personnel must, when practical (e.g., when platforms
are not constrained by fuel restrictions or mission-essential follow-on
commitments), observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel on these assets must assist
in the visual observation of the area where detonations occurred.
(7) Explosive missiles and rockets. Aircraft-deployed explosive
missiles and rockets. Mitigation applies to activities using a surface
target.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned in an aircraft. If additional platforms are participating
in the activity, Navy personnel positioned on those assets (e.g.,
safety observers, evaluators) must support observing the mitigation
zone for marine mammals and other applicable biological resources while
performing their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 900 yd around the intended impact location for missiles or rockets
with 0.6-20 lb net explosive weight.
(B) 2,000 yd around the intended impact location for missiles with
21-500 lb net explosive weight.
(C) Prior to the initial start of the activity (e.g., during a fly-
over of the mitigation zone), Navy personnel must observe the
mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must relocate or delay the start of firing.
(D) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease firing.
(E) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
intended impact location; or the mitigation zone has been clear from
any additional sightings for 10 min when the activity involves aircraft
that have fuel constraints, or 30 min when the activity involves
aircraft that are not typically fuel constrained.
(F) After completion of the activity (e.g., prior to maneuvering
off station), Navy personnel must, when practical (e.g., when platforms
are not constrained by fuel restrictions or mission-essential follow-on
commitments), observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel on these assets will assist
in the visual observation of the area where detonations occurred.
(8) Explosive bombs--(i) Number of Lookouts and observation
platform. One Lookout must be positioned in an aircraft conducting the
activity. If additional platforms are participating in the activity,
Navy personnel positioned on those assets (e.g., safety observers,
evaluators) must support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 2,500 yd around the intended target.
(B) Prior to the initial start of the activity (e.g., when arriving
on station), Navy personnel must observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel must relocate
or delay the start of bomb deployment.
(C) During the activity (e.g., during target approach), Navy
personnel must observe the mitigation zone for marine mammals; if
marine mammals are observed, Navy personnel must cease bomb deployment.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing bomb deployment) until one of the following
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
intended target; the mitigation zone has been
[[Page 46414]]
clear from any additional sightings for 10 min; or for activities using
mobile targets, the intended target has transited a distance equal to
double that of the mitigation zone size beyond the location of the last
sighting.
(E) After completion of the activity (e.g., prior to maneuvering
off station), Navy personnel must, when practical (e.g., when platforms
are not constrained by fuel restrictions or mission-essential follow-on
commitments), observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel on these assets must assist
in the visual observation of the area where detonations occurred.
(9) Sinking exercises--(i) Number of Lookouts and observation
platform. Two Lookouts (one must be positioned in an aircraft and one
must be positioned on a vessel). If additional platforms are
participating in the activity, Navy personnel positioned on those
assets (e.g., safety observers, evaluators) must support observing the
mitigation zone for marine mammals and other applicable biological
resources while performing their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 2.5 nmi around the target ship hulk.
(B) Prior to the initial start of the activity (90 min prior to the
first firing), Navy personnel must conduct aerial observations of the
mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must delay the start of firing.
(C) During the activity, Navy personnel must conduct passive
acoustic monitoring for marine mammals and use the information from
detections to assist visual observations. Navy personnel must visually
observe the mitigation zone for marine mammals from the vessel; if
marine mammals are observed, Navy personnel must cease firing.
Immediately after any planned or unplanned breaks in weapons firing of
longer than two hours, Navy personnel must observe the mitigation zone
for marine mammals from the aircraft and vessel; if marine mammals are
observed, Navy personnel must delay recommencement of firing.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the target
ship hulk; or the mitigation zone has been clear from any additional
sightings for 30 min.
(E) After completion of the activity (for two hours after sinking
the vessel or until sunset, whichever comes first), Navy personnel must
observe for marine mammals in the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed, Navy
personnel must follow established incident reporting procedures. If
additional platforms are supporting this activity (e.g., providing
range clearance), Navy personnel on these assets will assist in the
visual observation of the area where detonations occurred.
(10) Explosive mine countermeasure and neutralization activities--
(i) Number of Lookouts and observation platform. (A) One Lookout must
be positioned on a vessel or in an aircraft.
(B) If additional platforms are participating in the activity, Navy
personnel positioned on those assets (e.g., safety observers,
evaluators) must support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 600 yd around the detonation site.
(B) Prior to the initial start of the activity (e.g., when
maneuvering on station; typically 10 min when the activity involves
aircraft that have fuel constraints, or 30 min when the activity
involves aircraft that are not typically fuel constrained), Navy
personnel must observe the mitigation zone for marine mammals; if
marine mammals are observed, Navy personnel must relocate or delay the
start of detonations.
(C) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease detonations.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing detonations) until one of the following conditions
has been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to detonation
site; or the mitigation zone has been clear from any additional
sightings for 10 min when the activity involves aircraft that have fuel
constraints, or 30 min when the activity involves aircraft that are not
typically fuel constrained.
(F) After completion of the activity (typically 10 min when the
activity involves aircraft that have fuel constraints, or 30 min when
the activity involves aircraft that are not typically fuel
constrained), Navy personnel must observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), Navy personnel on these
assets must assist in the visual observation of the area where
detonations occurred.
(11) Explosive mine neutralization activities involving Navy
divers--(i) Number of Lookouts and observation platform. (A) Two
Lookouts (two small boats with one Lookout each, or one Lookout must be
on a small boat and one must be in a rotary-wing aircraft) when
implementing the smaller mitigation zone.
(B) Four Lookouts (two small boats with two Lookouts each), and a
pilot or member of an aircrew which must serve as an additional Lookout
if aircraft are used during the activity, must be used when
implementing the larger mitigation zone.
(C) All divers placing the charges on mines will support the
Lookouts while performing their regular duties and will report
applicable sightings to their supporting small boat or Range Safety
Officer.
(D) If additional platforms are participating in the activity, Navy
personnel positioned on those assets (e.g., safety observers,
evaluators) must support observing the mitigation zone for marine
mammals and other applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements. (A) For Lookouts on small
boats or aircraft, the mitigation zone must be 500 yd around the
detonation site under positive control.
(B) For Lookouts on small boats or aircraft, the mitigation zone
must be 1,000 yd around the detonation site during all activities using
time-delay fuses.
(C) For divers, the mitigation zone must be the underwater
detonation
[[Page 46415]]
location, which is defined as the sea space within the divers' range of
visibility but no further than the mitigation zone specified for
Lookouts on small boats or aircraft (500 yd or 1,000 yd depending on
the charge type).
(D) Prior to the initial start of the activity (when maneuvering on
station for activities under positive control; 30 min for activities
using time-delay firing devices), Navy Lookouts on small boats or
aircraft, must observe the mitigation zone for marine mammals; if
marine mammals are observed, Navy personnel must relocate or delay the
start of detonations or fuse initiation.
(E) During the activity, Navy Lookouts on small boats or aircraft,
must observe the mitigation zone for marine mammals; if marine mammals
are observed, Navy personnel must cease detonations or fuse initiation.
While performing their normal duties during the activity, divers must
observe the underwater detonation location for marine mammals. Divers
must notify their supporting small boat or Range Safety Officer of
marine mammal sightings at the underwater detonation location; if
observed, the Navy must cease detonations or fuse initiation. To the
maximum extent practicable depending on mission requirements, safety,
and environmental conditions, Navy personnel must position boats near
the mid-point of the mitigation zone radius (but outside of the
detonation plume and human safety zone), must position themselves on
opposite sides of the detonation location (when two boats are used),
and must travel in a circular pattern around the detonation location
with one Lookout observing inward toward the detonation site and the
other observing outward toward the perimeter of the mitigation zone. If
used, Navy aircraft must travel in a circular pattern around the
detonation location to the maximum extent practicable. Navy personnel
must not set time-delay firing devices to exceed 10 min.
(F) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the underwater detonation location or
mitigation zone (as applicable) prior to the initial start of the
activity (by delaying the start) or during the activity (by not
recommencing detonations or fuse initiation) until one of the following
conditions has been met: The animal is observed exiting the 500 yd or
1,000 yd mitigation zone; the animal is thought to have exited the 500
yd or 1,000 yd mitigation zone based on a determination of its course,
speed, and movement relative to the detonation site; or the 500 yd or
1,000 yd mitigation zones (for Lookouts on small boats or aircraft) and
the underwater detonation location (for divers) has been clear from any
additional sightings for 10 min during activities under positive
control with aircraft that have fuel constraints, or 30 min during
activities under positive control with aircraft that are not typically
fuel constrained and during activities using time-delay firing devices.
(G) After completion of an activity, the Navy must observe for
marine mammals for 30 min. Navy personnel must observe for marine
mammals in the vicinity of where detonations occurred; if any injured
or dead marine mammals are observed, Navy personnel must follow
established incident reporting procedures. If additional platforms are
supporting this activity (e.g., providing range clearance), Navy
personnel on these assets must assist in the visual observation of the
area where detonations occurred.
(12) Maritime security operations--anti-swimmer grenades--(i)
Number of Lookouts and observation platform. One Lookout must be
positioned on the small boat conducting the activity. If additional
platforms are participating in the activity, Navy personnel positioned
on those assets (e.g., safety observers, evaluators) must support
observing the mitigation zone for marine mammals and other applicable
biological resources while performing their regular duties.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 200 yd around the intended detonation location.
(B) Prior to the initial start of the activity (e.g., when
maneuvering on station), Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must relocate or delay the start of detonations.
(C) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease detonations.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing detonations) until one of the following conditions
has been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
intended detonation location; the mitigation zone has been clear from
any additional sightings for 30 min; or the intended detonation
location has transited a distance equal to double that of the
mitigation zone size beyond the location of the last sighting.
(E) After completion of the activity (e.g., prior to maneuvering
off station), Navy personnel must, when practical (e.g., when platforms
are not constrained by fuel restrictions or mission-essential follow-on
commitments), observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), Navy personnel on these assets will assist
in the visual observation of the area where detonations occurred.
(13) Vessel movement. The mitigation will not be applied if: The
vessel's safety is threatened; the vessel is restricted in its ability
to maneuver (e.g., during launching and recovery of aircraft or landing
craft, during towing activities, when mooring); the vessel is submerged
or operated autonomously; or if impracticable based on mission
requirements (e.g., during Amphibious Assault and Amphibious Raid
exercises).
(i) Number of Lookouts and observation platform. One Lookout must
be on the vessel that is underway.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 500 yd around whales.
(B) The mitigation zone must be 200 yd around all other marine
mammals (except bow-riding dolphins).
(C) During the activity. When underway Navy personnel must observe
the mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must maneuver to maintain distance.
(iii) Reporting. If a marine mammal vessel strike occurs, Navy
personnel must follow the established incident reporting procedures.
(14) Towed in-water devices. Mitigation applies to devices that are
towed from a manned surface platform or manned aircraft. The mitigation
will not be applied if the safety of the towing platform or in-water
device is threatened.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned on a manned towing platform.
[[Page 46416]]
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 250 yd around marine mammals.
(B) During the activity (i.e., when towing an in-water device),
Navy personnel must observe the mitigation zone for marine mammals; if
marine mammals are observed, Navy personnel must maneuver to maintain
distance.
(15) Small-, medium-, and large-caliber non-explosive practice
munitions. Mitigation applies to activities using a surface target.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned on the platform conducting the activity. Depending on the
activity, the Lookout could be the same as the one described for
``Weapons firing noise'' in paragraph (a)(3)(i) of this section.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 200 yd around the intended impact location.
(B) Prior to the initial start of the activity (e.g., when
maneuvering on station), Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must relocate or delay the start of firing.
(C) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease firing.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
intended impact location; the mitigation zone has been clear from any
additional sightings for 10 min for aircraft-based firing or 30 min for
vessel-based firing; or for activities using a mobile target, the
intended impact location has transited a distance equal to double that
of the mitigation zone size beyond the location of the last sighting.
(16) Non-explosive missiles and rockets. Aircraft-deployed non-
explosive missiles and rockets. Mitigation applies to activities using
a surface target.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned in an aircraft.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 900 yd around the intended impact location.
(B) Prior to the initial start of the activity (e.g., during a fly-
over of the mitigation zone), Navy personnel must observe the
mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must relocate or delay the start of firing.
(C) During the activity, Navy personnel must observe the mitigation
zone for marine mammals; if marine mammals are observed, Navy personnel
must cease firing.
(D) Commencement/recommencement conditions after a marine mammal
sighting prior to or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met: The animal is observed exiting the mitigation zone; the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to the
intended impact location; or the mitigation zone has been clear from
any additional sightings for 10 min when the activity involves aircraft
that have fuel constraints, or 30 min when the activity involves
aircraft that are not typically fuel constrained.
(17) Non-explosive bombs and mine shapes. Non-explosive bombs and
non-explosive mine shapes during mine laying activities.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned in an aircraft.
(ii) Mitigation zone and requirements. (A) The mitigation zone must
be 1,000 yd around the intended target.
(B) Prior to the initial start of the activity (e.g., when arriving
on station), Navy personnel must observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel must relocate
or delay the start of bomb deployment or mine laying.
(C) During the activity (e.g., during approach of the target or
intended minefield location), Navy personnel must observe the
mitigation zone for marine mammals and, if marine mammals are observed,
Navy personnel must cease bomb deployment or mine laying.
(D) Commencement/recommencement conditions after a marine mammal
sighting prior to or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing bomb deployment or mine laying) until one of the
following conditions has been met: The animal is observed exiting the
mitigation zone; the animal is thought to have exited the mitigation
zone based on a determination of its course, speed, and movement
relative to the intended target or minefield location; the mitigation
zone has been clear from any additional sightings for 10 min; or for
activities using mobile targets, the intended target has transited a
distance equal to double that of the mitigation zone size beyond the
location of the last sighting.
(b) Mitigation areas. In addition to procedural mitigation, Navy
personnel must implement mitigation measures within mitigation areas to
avoid or reduce potential impacts on marine mammals.
(1) Mitigation areas for marine mammals off Saipan in MITT Study
Area for sonar, explosives, and vessel strikes--(i) Mitigation area
requirements--(A) Marpi Reef and Chalan Kanoa Reef Geographic
Mitigation Areas. (1) Navy personnel will conduct a maximum combined
total of 20 hours annually from December 1 through April 30 of surface
ship hull-mounted MF1 mid-frequency active sonar during training and
testing within the Marpi Reef and Chalan Kanoa Reef Geographic
Mitigation Areas.
(2) Navy personnel will not use in-water explosives.
(3) Navy personnel must report the total hours of all active sonar
use (all bins, by bin) from December 1 through April 30 in these
geographic mitigation areas in the annual training and testing exercise
report submitted to NMFS.
(4) Should national security present a requirement to conduct
training or testing prohibited by the mitigation requirements in this
paragraph (b)(1)(i)(A), Navy personnel must obtain permission from the
appropriate designated Command authority prior to commencement of the
activity. Navy personnel must provide NMFS with advance notification
and include relevant information (e.g., sonar hours, explosives use) in
its annual activity reports submitted to NMFS.
(B) Marpi Reef and Chalan Kanoa Reef Awareness Notification Message
Area. (1) Navy personnel must issue a seasonal awareness notification
message to alert Navy ships and aircraft operating in the Marpi Reef
and Chalan Kanoa Reef Geographic Mitigation Areas to the possible
presence of increased concentrations of humpback whales from December 1
through April 30.
[[Page 46417]]
(2) To maintain safety of navigation and to avoid interactions with
large whales during transits, Navy personnel must instruct vessels to
remain vigilant to the presence of humpback whales that when
concentrated seasonally, may become vulnerable to vessel strikes.
(3) Navy personnel must use the information from the awareness
notification message to assist their visual observation of applicable
geographic mitigation zones during training and testing activities and
to aid in the implementation of procedural mitigation.
(ii) [Reserved]
(2) Mitigation areas for marine mammals off Guam of the MITT Study
Area for sonar and explosives--(i) Mitigation area requirements--(A)
Agat Bay Nearshore Geographic Mitigation Area. (1) Navy personnel will
not conduct MF1 surface ship hull-mounted mid-frequency active sonar
year-round.
(2) Navy personnel will not use in-water explosives year-round.
(3) Should national security require the use of MF1 surface ship
hull-mounted mid-frequency active sonar or explosives within the Agat
Bay Nearshore Geographic Mitigation Area, Navy personnel must obtain
permission from the appropriate designated Command authority prior to
commencement of the activity. Navy personnel must provide NMFS with
advance notification and include the information (e.g., sonar hours,
explosives usage) in its annual activity reports submitted to NMFS.
(B) [Reserved]
Sec. 218.95 Requirements for monitoring and reporting.
(a) Unauthorized take. Navy personnel must notify NMFS immediately
(or as soon as operational security considerations allow) if the
specified activity identified in Sec. 218.90 is thought to have
resulted in the serious injury or mortality of any marine mammals, or
in any Level A harassment or Level B harassment of marine mammals not
identified in this subpart.
(b) Monitoring and reporting under the LOA. The Navy must conduct
all monitoring and reporting required under the LOA, including abiding
by the U.S. Navy's Marine Species Monitoring Program for the MITT Study
Area. Details on program goals, objectives, project selection process,
and current projects are available at
www.navymarinespeciesmonitoring.us.
(c) Notification of injured, live stranded, or dead marine mammals.
Navy personnel must consult the Notification and Reporting Plan, which
sets out notification, reporting, and other requirements when dead,
injured, or live stranded marine mammals are detected. The Notification
and Reporting Plan is available at https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-mariana-islands-training-and-testing-mitt.
(d) Annual MITT Study Area marine species monitoring report. The
Navy must submit an annual report to NMFS of the MITT Study Area
monitoring which will be included in a Pacific-wide monitoring report
including results specific to the MITT Study Area describing the
implementation and results from the previous calendar year. Data
collection methods will be standardized across Pacific Range Complexes
including the MITT, HSTT, NWTT, and Gulf of Alaska (GOA) Study Areas to
the best extent practicable, to allow for comparison in different
geographic locations. The report must be submitted to the Director,
Office of Protected Resources, NMFS, either within three months after
the end of the calendar year, or within three months after the
conclusion of the monitoring year, to be determined by the Adaptive
Management process. NMFS will submit comments or questions on the draft
monitoring report, if any, within three months of receipt. The report
will be considered final after the Navy has addressed NMFS' comments,
or three months after the submittal of the draft if NMFS does not
provide comments on the draft report. Such a report will describe
progress of knowledge made with respect to monitoring study questions
across multiple Navy ranges associated with the ICMP. Similar study
questions must be treated together so that progress on each topic can
be summarized across multiple Navy ranges. The report need not include
analyses and content that does not provide direct assessment of
cumulative progress on the monitoring study question. This will
continue to allow the Navy to provide a cohesive monitoring report
covering multiple ranges (as per ICMP goals), rather than entirely
separate reports for the MITT, Hawaii-Southern California, Gulf of
Alaska, and Northwest Training and Testing Study Areas.
(e) Annual MITT Study Area Training and Testing Exercise Report.
Each year, the Navy must submit a preliminary report (Quick Look
Report) detailing the status of authorized sound sources within 21 days
after the anniversary of the date of issuance of the LOA to the
Director, Office of Protected Resources, NMFS. The Navy must also
submit a detailed report (MITT Annual Training and Testing Exercise
Report) to the Director, Office of Protected Resources, NMFS, within
three months after the one-year anniversary of the date of issuance of
the LOA. The MITT Annual Training and Testing Exercise Report can be
consolidated with other exercise reports from other range complexes in
the Pacific Ocean for a single Pacific Exercise Report, if desired.
NMFS will submit comments or questions on the report, if any, within
one month of receipt. The report will be considered final after the
Navy has addressed NMFS' comments, or one month after submittal of the
draft if NMFS does not provide comments on the draft report. The annual
will contain information on major training exercises (MTEs), Sinking
Exercise (SINKEX) events, and a summary of all sound sources used
(total hours or quantity of each bin of sonar or other non-impulsive
source; total annual number of each type of explosive exercises; and
total annual expended/detonated rounds (missiles, bombs, sonobuoys,
etc.) for each explosive bin). The annual report will also contain
information on sound sources used including within specific mitigation
reporting areas as described in paragraph (e)(4) of this section. The
annual report will also contain both the current year's data as well as
cumulative sonar and explosive use quantity from previous years'
reports. Additionally, if there were any changes to the sound source
allowance in a given year, or cumulatively, the report will include a
discussion of why the change was made and include analysis to support
how the change did or did not affect the analysis in the 2020 MITT
FSEIS/OEIS and MMPA final rule. The annual report will also include the
details regarding specific requirements associated with specific
mitigation areas. The final annual/close-out report at the conclusion
of the authorization period (year seven) will serve as the
comprehensive close-out report and include both the final year annual
use compared to annual authorization as well as a cumulative seven-year
annual use compared to seven-year authorization. The detailed reports
must contain the information identified in paragraphs (e)(1) through
(6) of this section.
(1) MTEs. This section of the report must contain the following
information for MTEs conducted in the MITT Study Area.
(i) Exercise information for each MTE.
(A) Exercise designator.
(B) Date that exercise began and ended.
(C) Location.
(D) Number and types of active sonar sources used in exercise.
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(E) Number and types of passive acoustic sources used in exercise.
(F) Number and types of vessels, aircraft, and other platforms
participating in exercise.
(G) Total hours of all active sonar source operation.
(H) Total hours of each active sonar source bin.
(I) Wave height (high, low, and average) during exercise.
(ii) Individual marine mammal sighting information for each
sighting in each exercise where mitigation was implemented.
(A) Date/Time/Location of sighting.
(B) Species (if not possible, indication of whale or dolphin).
(C) Number of individuals.
(D) Initial Detection Sensor (e.g., sonar, Lookout).
(E) Indication of specific type of platform observation was made
from (including, for example, what type of surface vessel or testing
platform).
(F) Length of time observers maintained visual contact with marine
mammal.
(G) Sea state.
(H) Visibility.
(I) Sound source in use at the time of sighting.
(J) Indication of whether the animal was less than 200 yd, 200 to
500 yd, 500 to 1,000 yd, 1,000 to 2,000 yd, or greater than 2,000 yd
from sonar source.
(K) Whether operation of sonar sensor was delayed, or sonar was
powered or shut down, and how long the delay.
(L) If source in use was hull-mounted, true bearing of animal from
the vessel, true direction of vessel's travel, and estimation of
animal's motion relative to vessel (opening, closing, parallel).
(M) Lookouts must report, in plain language and without trying to
categorize in any way, the observed behavior of the animal(s) (such as
animal closing to bow ride, paralleling course/speed, floating on
surface and not swimming, etc.) and if any calves were present.
(iii) An evaluation (based on data gathered during all of the MTEs)
of the effectiveness of mitigation measures designed to minimize the
received level to which marine mammals may be exposed. This evaluation
must identify the specific observations that support any conclusions
the Navy reaches about the effectiveness of the mitigation.
(2) SINKEXs. This section of the report must include the following
information for each SINKEX completed that year.
(i) Exercise information gathered for each SINKEX.
(A) Location.
(B) Date and time exercise began and ended.
(C) Total hours of observation by Lookouts before, during, and
after exercise.
(D) Total number and types of explosive source bins detonated.
(E) Number and types of passive acoustic sources used in exercise.
(F) Total hours of passive acoustic search time.
(G) Number and types of vessels, aircraft, and other platforms,
participating in exercise.
(H) Wave height in feet (high, low, and average) during exercise.
(I) Narrative description of sensors and platforms utilized for
marine mammal detection and timeline illustrating how marine mammal
detection was conducted.
(ii) Individual marine mammal observation (by Navy Lookouts)
information for each sighting where mitigation was implemented.
(A) Date/Time/Location of sighting.
(B) Species (if not possible, indicate whale or dolphin).
(C) Number of individuals.
(D) Initial detection sensor (e.g., sonar or Lookout).
(E) Length of time observers maintained visual contact with marine
mammal.
(F) Sea state.
(G) Visibility.
(H) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after.
(I) Distance of marine mammal from actual detonations (or target
spot if not yet detonated): Less than 200 yd, 200 to 500 yd, 500 to
1,000 yd, 1,000 to 2,000 yd, or greater than 2,000 yd.
(J) Lookouts must report, in plain language and without trying to
categorize in any way, the observed behavior of the animal(s) (such as
animal closing to bow ride, paralleling course/speed, floating on
surface and not swimming etc.), including speed and direction and if
any calves were present.
(K) The report must indicate whether explosive detonations were
delayed, ceased, modified, or not modified due to marine mammal
presence and for how long.
(L) If observation occurred while explosives were detonating in the
water, indicate munition type in use at time of marine mammal
detection.
(3) Summary of sources used. This section of the report must
include the following information summarized from the authorized sound
sources used in all training and testing events:
(i) Total annual hours or quantity (per the LOA) of each bin of
sonar or other transducers; and
(ii) Total annual expended/detonated ordnance (missiles, bombs,
sonobuoys, etc.) for each explosive bin.
(4) Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas.
The Navy must report any active sonar use (all bins, by bin) between
December 1 and April 30 that occurred as specifically described in
these areas. Information included in the classified annual reports may
be used to inform future adaptive management within the MITT Study
Area.
(5) Geographic information presentation. The reports must present
an annual (and seasonal, where practical) depiction of training and
testing bin usage geographically across the MITT Study Area.
(6) Sonar exercise notification. The Navy must submit to NMFS
(contact as specified in the LOA) an electronic report within fifteen
calendar days after the completion of any MTE indicating:
(i) Location of the exercise;
(ii) Beginning and end dates of the exercise; and
(iii) Type of exercise.
(f) Final Close-Out Report. The final (year seven) draft annual/
close-out report must be submitted within three months after the
expiration of this subpart to the Director, Office of Protected
Resources, NMFS. NMFS must submit comments on the draft close-out
report, if any, within three months of receipt. The report will be
considered final after the Navy has addressed NMFS' comments, or three
months after the submittal of the draft if NMFS does not provide
comments.
Sec. 218.96 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to the regulations
in this subpart, the Navy must apply for and obtain an LOA in
accordance with Sec. 216.106 of this section.
(b) An LOA, unless suspended or revoked, may be effective for a
period of time not to exceed July 30, 2027.
(c) If an LOA expires prior to July 30, 2027, the Navy may apply
for and obtain a renewal of the LOA.
(d) In the event of projected changes to the activity or to
mitigation, monitoring, or reporting (excluding changes made pursuant
to the adaptive management provision of Sec. 218.97(c)(1)) required by
an LOA issued under this subpart, the Navy must apply for and obtain a
modification of the LOA as described in Sec. 218.97.
(e) Each LOA will set forth:
(1) Permissible methods of incidental taking;
(2) Geographic areas for incidental taking;
(3) Means of effecting the least practicable adverse impact (i.e.,
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mitigation) on the species of marine mammals and their habitat; and
(4) Requirements for monitoring and reporting.
(f) Issuance of the LOA(s) must be based on a determination that
the level of taking is consistent with the findings made for the total
taking allowable under the regulations in this subpart.
(g) Notice of issuance or denial of the LOA(s) will be published in
the Federal Register within 30 days of a determination.
Sec. 218.97 Renewals and modifications of Letters of Authorization.
(a) An LOA issued under Sec. Sec. 216.106 of this section and
218.96 for the activity identified in Sec. 218.90(c) may be renewed or
modified upon request by the applicant, provided that:
(1) The planned specified activity and mitigation, monitoring, and
reporting measures, as well as the anticipated impacts, are the same as
those described and analyzed for the regulations in this subpart
(excluding changes made pursuant to the adaptive management provision
in paragraph (c)(1) of this section); and
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOA(s) were implemented.
(b) For LOA modification or renewal requests by the applicant that
include changes to the activity or to the mitigation, monitoring, or
reporting measures (excluding changes made pursuant to the adaptive
management provision in paragraph (c)(1) of this section) that do not
change the findings made for the regulations or result in no more than
a minor change in the total estimated number of takes (or distribution
by species or years), NMFS may publish a notice of planned LOA in the
Federal Register, including the associated analysis of the change, and
solicit public comment before issuing the LOA.
(c) An LOA issued under Sec. Sec. 216.106 of this section and
218.96 may be modified by NMFS under the following circumstances:
(1) Adaptive management. After consulting with the Navy regarding
the practicability of the modifications, NMFS may modify (including
adding or removing measures) the existing mitigation, monitoring, or
reporting measures if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of the mitigation and monitoring.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA
include:
(A) Results from the Navy's annual monitoring report and annual
exercise report from the previous year(s);
(B) Results from other marine mammal and/or sound research or
studies;
(C) Results from specific stranding investigations; or
(D) Any information that reveals marine mammals may have been taken
in a manner, extent, or number not authorized by the regulations in
this subpart or subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
will publish a notice of planned LOA in the Federal Register and
solicit public comment.
(2) Emergencies. If NMFS determines that an emergency exists that
poses a significant risk to the well-being of the species of marine
mammals specified in LOAs issued pursuant to Sec. Sec. 216.106 of this
section and 218.96, an LOA may be modified without prior notice or
opportunity for public comment. Notice will be published in the Federal
Register within thirty days of the action.
[FR Doc. 2020-15651 Filed 7-30-20; 8:45 am]
BILLING CODE 3510-22-P