[Federal Register Volume 85, Number 100 (Friday, May 22, 2020)]
[Notices]
[Pages 31146-31159]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-11116]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XA128]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Ward Cove Cruise Ship Dock Project,
Juneau, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
-----------------------------------------------------------------------
SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
Power Systems & Supplies of Alaska (PSSA) to incidentally harass, by
Level A and B harassment only, marine mammals during construction
activities associated with the Ward Cove Cruise Ship Dock Project near
Ketchikan, Alaska.
DATES: This authorization is effective for one year from the date of
issuance.
FOR FURTHER INFORMATION CONTACT: Dwayne Meadows, Ph.D., Office of
Protected Resources, NMFS, (301) 427-8401. Electronic copies of the
application and supporting documents, as well as a list of the
references cited in this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these
documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) 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 incidental take authorization may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) 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 the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth.
The definitions of all applicable MMPA statutory terms cited above
are included in the relevant sections below.
Summary of Request
On December 30, 2019, NMFS received a request from PSSA for an IHA
to take marine mammals incidental to Ward Cove Cruise Ship Dock Project
near Ketchikan, Alaska. The application was deemed adequate and
complete on February 5, 2020. PSSA's request is for take of four
species by Level B harassment and/or Level A harassment. Neither PSSA
nor NMFS expects serious injury or mortality to result from this
activity and, therefore, an IHA is appropriate.
Description of the Specified Activity
Overview
The project consists of the construction of a cruise ship dock for
two cruise ships in Ward Cove, approximately 8 kilometers (5 miles)
north of downtown Ketchikan, Alaska. PSSA would install a pile
supported 500-foot by 70-foot (152 by 21 m) floating pontoon dock,
mooring structures, and shore-access transfer span and trestle. The
project includes the following in-water components: Driving 102, 30-48
inch diameter steel pipe piles to support the structures and removal of
48 of these piles (all 30-inch diameter) that are being used solely as
templates to guide installation of larger permanent piles. It is
expected to take no more than 105 days of in-water work. Pile driving
would be by vibratory pile driving until resistance is too great and
driving would switch to an impact hammer. Removal of temporary piles
would use vibratory methods only. Forty larger 36- and 48-inch piles
would also be rock anchored into place using a down-the-hole (DTH)
hammer.
A detailed description of the planned project is provided in the
Federal
[[Page 31147]]
Register notice for the proposed IHA (85 FR 12523; March 3, 2020).
Since that time, no changes have been made to the planned activities.
Therefore, a detailed description is not provided here. Please refer to
that Federal Register notice for the full description of the specific
activity.
Mitigation, monitoring, and reporting measures are described in
detail later in this document (please see Mitigation and Monitoring and
Reporting).
Comments and Responses
A notice of NMFS's proposal to issue an IHA to PSSA was published
in the Federal Register on March 3, 2020 (85 FR 12523). That notice
described, in detail, PSSA's activity, the marine mammal species that
may be affected by the activity, and the anticipated effects on marine
mammals. During the 30-day public comment period, NMFS received public
comment from two individuals generally opposed to cruise ships, but
with no comments specific to the authorization. The U.S. Geological
Survey noted they have ``no comment to offer at this time''. Defenders
of Wildlife (Defenders) provided comments we address below. A comment
letter from the Marine Mammal Commission (Commission) was received
pursuant to the Commission's authority to recommend steps it deems
necessary or desirable to protect and conserve marine mammals (16
U.S.C. 1402.202(a)). We are obligated to respond to the Commission's
recommendations within 120 days, and we do so below.
Comment: Defenders requested we extend the comment period.
Response: In their comment letter Defenders provided specific
comments on the action. They did not note knowledge of any other
members of the public that would be providing public comments. We
received a larger than normal number of public comments on this action.
The project is already underway (with additional mitigation measures
that are intended to avoid marine mammal take). Thus there is no
evidence than any member of the public would be disadvantaged by not
being able to comment on this action and the current work does not
benefit from MMPA coverage until an authorization is issued; therefore
we decline to extend the comment period.
Comment: Defenders notes that the Army Corps of Engineers permit
and the ESA Section 7 Letter of Concurrence (LOC) provide different
dates for when activities will need to cease to protect ESA listed
species and that the IHA is unclear about these limits.
Response: The ESA LOC does state that in-water work will be
completed by May of each year and the Army Corps permit does state that
PSSA will follow the LOC, despite the conflicting language elsewhere.
Should in-water work extend beyond May, the LOC would no longer be
applicable, but that is not a requirement of this MMPA authorization.
However, in fact the LOC has been extended through September 30, 2020.
Comment: Defenders noted that Mexico DPS humpback whales may
increase in frequency as summer progresses. They suggested that we
should require in-water work to be completed by the end of May.
Response: PSSA chose not to request take of humpback whales and to
instead shutdown work should whales enter the shutdown zone in Tongass
Narrows (they are not likely to enter Ward Cove). Based on the first
two months of project reports submitted to NMFS Alaska Region Office in
response to the LOC, PSSA has observed two pods of humpback whales and
were successfully able to observe them and shut down the project
without take occurring. This justifies our initial determination that
the Protected Species Observers (PSOs) will see humpback before they
cross through the relatively discrete area of Tongass Narrows that
might be ensonified above the threshold. As noted above, the LOC has
been extended through September 30, 2020.
Comment: The Commission recommends that NMFS refrain from issuing
renewals for any authorization and instead use its abbreviated Federal
Register notice process. They further recommend that if NMFS uses
renewals, we (1) stipulate in all Federal Register notices and
authorizations that a renewal is a one-time opportunity and, (2) if
NMFS refuses to stipulate a renewal being a one-time opportunity,
explain why it will not do so.
Response: NMFS does not agree with the Commission and, therefore,
does not adopt the Commission's recommendation. NMFS will provide a
detailed explanation of its decision within 120 days, as required by
section 202(d) of the MMPA.
Comment: The Commission recommended that NMFS continue to include
in all draft and final IHAs the explicit requirements to cease
activities if a marine mammal is injured or killed during the proposed
activities until NMFS reviews the circumstances involving any injury or
death that has been attributed to the activities and determines what
additional measures are necessary to minimize additional injuries or
deaths.
Response: NMFS concurs with the Commission's recommendation as it
relates to this IHA, and construction IHAs in general, and has added
the referenced language to the Monitoring and Reporting section of this
notice and the Reporting section of the issued IHA. We will continue to
evaluate inclusion of this language in future IHAs.
Comment: The Commission again recommends that NMFS (1) have its
experts in underwater acoustics and bioacoustics review and finalize
its recommended proxy source levels for both impact and vibratory
installation of the various pile types and sizes and (2) make available
to action proponents the database of proxy source levels.
Response: NMFS appreciates the Commission's interest in this issue
and, as we have indicated previously, we are working on developing such
a product.
Comment: The Commission made a number of comments with regard to
DTH hammering. The Commission recommends NMFS consider DTH hammering as
impulsive. They further recommend that NMFS (1) require action
proponents to provide the necessary operational information and
characteristics for DTH hammering in each relevant application
irrespective of what terminology is used, (2) encourage action
proponents to use consistent terminology regarding DTH hammering in all
relevant applications, and (3) use consistent terminology in all future
Federal Register notices and draft and final authorizations that
involve DTH hammering. Finally, the Commission recommends that NMFS re-
estimate the Level A harassment zones for DTH hammering based on source
levels provided either by Reyff and Heyvaert (2019) or Denes et al.
(2019) and increase the numbers of Level A harassment takes
accordingly.
Response: We agree with the Commission that as knowledge of the
variety of DTH methods and uses grows, more information from applicants
on operational information and characteristics of DTH, and more
consistent terminology, is beneficial.
NMFS acknowledges that DTH piling operations can include both
impulsive and continuous noise components. The limited available data
show that the specific acoustic characteristics of any particular DTH
piling operation can vary significantly, based on the extent of the
continuous non-pulse acoustic components of the drilling/pumping and
the impulsive acoustic components of the hammering, as well as the
nature of the environment (especially bottom characteristics).
Currently, given the potential variation in the acoustic output from
any specific operation and
[[Page 31148]]
the limited in situ measurements of DTH hammering available, NMFS is
taking a conservative approach until more data are available.
Specifically, we recommend estimating the potential impulsive
components (and using the associated thresholds) of the operations for
the purposes of predicting Level A harassment and estimating the
potential continuous components (and using the associated threshold)
for the purposes of predicting Level B harassment. Further, given the
strengths, weaknesses, and characteristics of the available data, until
additional measurements and analyses are available for consideration,
we recommend using the Denes et al. (2019) source levels as a proxy
source level for the purposes of the Level A harassment assessment and
the Denes et al. (2016) for the purposes of the Level B harassment
assessment.
We note that Denes et al. (2019) used a 42-inch drill bit to drill
much larger holes than the 33-inch drill bit and holes of this project.
The larger drill bits drill an area 38.2 percent larger, likely
creating louder sounds from the larger area of contact with rock, which
means that the Level A harassment zones may be overestimated to some
degree for this project. As a result of the increased size of the Level
A harassment zones we have added harbor and Dall's porpoises to the 200
m shutdown zone requirement and added 15 Level A harassment takes for
each species.
We note also that the Commission erroneously claimed PSSA was using
a top head drive system, but the application clearly notes the system
is a DTH system.
Comment: The Commission recommends that NMFS require all applicants
that propose to use a DTH hammer to install piles, including PSSA, to
conduct in-situ measurements, ensure that signal processing is
conducted appropriately, and adjust the Level A and B harassment zones
accordingly.
Response: As required by their ESA Section 7 concurrence letter,
PSSA is conducting in-situ sound monitoring of multiple piles. We will
evaluate the need to require such measures for future projects on a
case-by-case basis, though we acknowledge the general need for more
data on these sources.
Changes From the Proposed IHA to Final IHA
The sound source levels used to calculate impact pile driving
harassment ones were measured at 11 m from the source and we failed to
correct them to the standard 10 m source level distance criterion used
in calculations. As a result harassment zone sizes increased slightly
(see Estimated Take section below for full details). As a result of
these changes, and observations of Steller's sea lions in the project
area since the project started, we are adding take of Steller's sea
lions to the authorization at the request of the applicant (see
Estimated Take section below for full details).
As discussed above in the Comments and Responses section, we are
changing the approach to DTH hammering so that we estimate the
potential impulsive components (using the associated thresholds) of the
operations for the purposes of predicting Level A harassment and
estimate the potential continuous components (using the associated
threshold) for the purposes of predicting Level B harassment. We use
the Denes et al. (2019) source levels as a proxy source level for the
purposes of the Level A harassment assessment. As a result of the
increased size of the Level A harassment zones we have added harbor and
Dall's porpoises to the 200 m shutdown zone requirement and added 15
Level A harassment takes for each species. We add the explicit
requirements to cease activities if a marine mammal is injured or
killed during the proposed activities until NMFS reviews the
circumstances to the Monitoring and Reporting section of this notice
and the Reporting section of the issued IHA. Minor typographical errors
were also corrected.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history, of the potentially affected species.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (https://www.fisheries.noaa.gov/find-species).
Table 1 lists all species with expected potential for occurrence in
the project area near Ketchikan, Alaska and summarizes information
related to the population or stock, including regulatory status under
the MMPA and ESA and potential biological removal (PBR), where known.
For taxonomy, we follow Committee on Taxonomy (2019). PBR is defined by
the MMPA as the maximum number of animals, not including natural
mortalities, that may be removed from a marine mammal stock while
allowing that stock to reach or maintain its optimum sustainable
population (as described in NMFS's SARs). While no mortality is
anticipated or authorized here, PBR and annual serious injury and
mortality from anthropogenic sources are included here as gross
indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Alaska SARs (e.g., Muto et al. 2019). All values presented
in Table 1 are the most recent available at the time of publication and
are available in the 2019 draft SARs (Muto et al., 2019).
Table 1--Marine Mammals That Could Occur in the Proposed Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock abundance Nbest,
ESA/ MMPA status; (CV, Nmin, most recent Annual M/
Common name Scientific name MMPA stock strategic (Y/N) 1 abundance survey) 2 PBR SI 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray Whale...................... Eschrichtius robustus.. Eastern North Pacific.. -, -, N 26,960 (0.05, 25,849, 801 138
2016).
Family Balaenidae:
Humpback whale.................. Megaptera novaeangliae. Central North Pacific.. E, D,Y 10,103 (0.3; 7,891; 83 25
2006).
[[Page 31149]]
Minke whale..................... Balaenoptera Alaska................. -, N N.A................... N.A. N.A.
acutorostrata.
Fin whale....................... Balaenoptera physalus.. Northeast Pacific...... E, D, Y N.A................... 5.1 0.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer whale.................... Orcinus orca........... Alaska Resident........ -, N 2,347 (N.A.; 2,347; 24 1
2012).
West Coast Transient... -, N 243 (N.A, 243, 2009).. 2.4 0
Northern Resident...... -, N 302 (N.A.; 302, 2018). 2.2 0.2
Pacific white-sided dolphin..... Lagenorhynchus North Pacific.......... -,-; N 26,880 (N.A.; N.A.; N.A. 0
obliquidens. 1990).
Family Phocoenidae:
Harbor porpoise................. Phocoena phocoena...... Southeast Alaska....... -, Y 975 (0.10; 896; 2012). 8.95 34
Dall's porpoise................. Phocoenoides dalli..... Alaska................. -, N N.A................... N.A. 38
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Eastern U.S............ -,-, N 43,201 (N.A.; 43,201; 2,592 113
2017).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina Clarence Strait........ -, N 27,659 (N.A.; 24,854; 746 40
richardii. 2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
1 Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
2 NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N.A.).
3 These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
with estimated mortality due to commercial fisheries is presented in some cases.
A detailed description of the of the species likely to be affected
by this project, including brief introductions to the species and
relevant stocks as well as available information regarding population
trends and threats, and information regarding local occurrence, were
provided in the Federal Register notice for the proposed IHA (85 FR
12523; March 3, 2020); since that time, we are not aware of any changes
in the status of these species and stocks; therefore, detailed
descriptions are not provided here. Please refer to that Federal
Register notice for these descriptions. As noted above however, we are
adding take of Steller's sea lions to the authorization at the request
of the applicant so a description of this species follows.
Steller's Sea Lion
Steller sea lions (Eumetopias jubatus) were listed as threatened
range-wide under the ESA on November 26, 1990 (55 FR 49204). Steller
sea lions were subsequently partitioned into the western and eastern
Distinct Population Segments (DPSs; western and eastern stocks) in 1997
(62 FR 24345, May 5, 1997). The eastern DPS was delisted in 2013. The
eastern DPS is the only population of Steller's sea lions thought to
occur in the project area. The current minimum abundance estimate for
the eastern DPS of Steller sea lions is 43,201 individuals (Muto et al.
2019).
The nearest known Steller sea lion haulout is located approximately
17 miles (27 km) west/northwest of Ketchikan on Grindall Island. Summer
counts of adult and juvenile sea lions at this haulout since 2000 have
averaged approximately 191 individuals, with a range from 6 in 2009 to
378 in 2008. No sea lion pups have been observed at this haulout.
No systematic studies of sea lion abundance or distribution have
occurred in Tongass Narrows. Anecdotal reports suggest that Steller sea
lions may be found in Tongass Narrows year-round, with an increase in
abundance from March to early May during the herring spawning season,
and another increase in late summer associated with salmon runs.
Overall sea lion presence in Tongass Narrows tends to be lower in
summer than in winter (FHWA 2017). During summer, Steller sea lions may
aggregate outside the project area, at rookery and haulout sites.
Monitoring during construction of the Ketchikan Ferry Terminal in
summer (July 16 through August 17, 2016) did not record any Steller sea
lions.
Sea lions are known to transit through Tongass Narrows while
pursuing prey. Steller sea lions are known to follow fishing vessels,
and may congregate in small numbers at seafood processing facilities
and hatcheries or at the mouths of rivers and creeks containing
hatcheries, where large numbers of salmon congregate in late summer.
Three seafood processing facilities are located east of the proposed
project location on Revilla Island, and two salmon hatcheries operated
by the Alaska Department of Fish & Game (ADF&G) are located east of the
project area. Steller sea lions may aggregate near the mouth of
Ketchikan Creek, where a hatchery upstream supports a summer salmon
run. The Creek mouth is more than 9 kilometers (5.5 miles) east of the
entrance to Ward Cove.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from PSSA's construction activities
have the potential to result in behavioral harassment of marine mammals
in the vicinity of the survey area. The notice of proposed IHA (85 FR
12523; March 3, 2020) included a discussion of the effects of
anthropogenic noise on marine mammals and the potential effects of
underwater noise from PSSA's survey activities on marine mammals and
their habitat. That information and analysis is incorporated by
reference into this final IHA determination and is not repeated
[[Page 31150]]
here; please refer to the notice of proposed IHA (85 FR 12523; March 3,
2020).
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through this IHA, which will inform both NMFS' consideration
of ``small numbers'' and the negligible impact determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic source (i.e., vibratory or impact pile driving or DTH)
has the potential to result in disruption of behavioral patterns for
individual marine mammals. There is also some potential for auditory
injury (Level A harassment) to result for pinnipeds because predicted
auditory injury zones are larger and harbor seals are the only animals
routinely seen in Ward Cove. The mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent
practicable.
As described previously, no mortality is anticipated or authorized
for this activity. Below we describe how the take is estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Due to the lack of marine
mammal density, NMFS relied on local occurrence data and group size to
estimate take. Below, we describe the factors considered here in more
detail and present the take estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur
Permanent Threshold Shift (PTS) of some degree (equated to Level A
harassment).
Level B Harassment for non-explosive sources--Though significantly
driven by received level, the onset of 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 (e.g., hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals are
likely to be behaviorally harassed in a manner we consider Level B
harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 microPascal ([mu]Pa) (root mean square
(rms)) for continuous (e.g., vibratory pile-driving, drilling) and
above 160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g.,
impact pile driving) or intermittent (e.g., scientific sonar) sources.
PSSA's proposed activity includes the use of continuous (vibratory
pile-driving, DTH) and impulsive (impact pile-driving) sources, and
therefore the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are
applicable.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0) (Technical Guidance, 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). PSSA's activity includes the use of
impulsive (impact pile-driving, as well as DTH hammering, which
includes impulsive components) and non-impulsive (vibratory pile
driving/removal and drilling) sources.
These thresholds are provided in Table 2. The references, analysis,
and methodology used in the development of the thresholds are described
in NMFS 2018 Technical Guidance, which may be accessed at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds \*\ (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
[[Page 31151]]
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected via sound generated by the
primary components of the project (i.e., impact pile driving, vibratory
pile driving, vibratory pile removal, and DTH).
Vibratory hammers produce constant sound when operating, and
produce vibrations that liquefy the sediment surrounding the pile,
allowing it to penetrate to the required seating depth. An impact
hammer would then generally be used to place the pile at its intended
depth through rock or harder substrates. The actual durations of each
installation method vary depending on the type and size of the pile. An
impact hammer is a steel device that works like a piston, producing a
series of independent strikes to drive the pile. Impact hammering
typically generates the loudest noise associated with pile
installation.
In order to calculate distances to the Level A harassment and Level
B harassment sound thresholds for piles of various sizes being used in
this project, NMFS used acoustic monitoring data from other locations
to develop source levels (see Table 3). Note that piles of differing
sizes have different sound source levels (SSLs).
Empirical data from recent Alaska Department of Transportation
(ADOT&PF) sound source verification (SSV) studies at Ketchikan were
used to estimate sound source levels for vibratory driving of 30-inch
steel pipe piles. Data from Ketchikan was used because of its proximity
to this project in Tongass. Data from Anchorage were used for vibratory
driving of 36 and 48-inch piles and for impact driving of 30, 36, and
48-inch piles (Austin et al. 2016). Source levels from 48-inch piles
were used as a proxy for the 30 and 36-inch piles for impact pile
driving and for the 36-inch piles for vibratory driving, making those
estimated source levels conservative.
For DTH for rock anchoring, source level data from a project in
Kodiak were used for the continuous characteristics of DTH (Denes et
al. 2016) and data from Denes et al. (2019) were used for the impulsive
characteristics. The reported median source value for DTH from Denes et
al. (2016) was 166.2 dB rms for all pile types (see Table 72).
Table 3--Estimates of Underwater Sound Levels Generated During Vibratory and Impact Pile Installation, Drilling,
and Vibratory Pile Removal
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Method and pile type Sound source level at 10 meters Literature source
----------------------------------------------------------------------------------------------------------------
Vibratory Hammer................ dB rms.
30-inch steel piles............. 161.9. Denes et al. 2016,
Table 72.
36-inch steel piles............. 168.2. Austin et al.
2016, Table 16.
48-inch steel piles............. 168.2. Austin et al.
2016, Table 16.
DTH Rock Anchors (Continuous)... dB rms.
All pile diameters.............. 166.2. Denes et al. 2016,
Table 72.
----------------------------------------------------------------------------------------------------------------
DTH Rock Anchors (Impulsive).... dB peak........... db RMS............ dB SS SEL.........
All pile diameters.............. 190............... 180............... 164............... Denes et al. 2019.
Impact Hammer................... dB peak........... .................. dB SS SEL.........
All pile diameters.............. 212.5............. .................. 186.7............. Austin et al.
2016, Tables 7,
9.
----------------------------------------------------------------------------------------------------------------
Note: It is assumed that noise levels during pile installation and removal are similar. Use of an impact hammer
will be limited to 5-10 minutes per pile, if necessary. It is assumed that drilling produces the same SSL for
both pile diameters. SS SEL = single strike sound exposure level; dB peak = peak sound level; rms = root mean
square.
Level B Harassment Zones
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
where:
TL = B * Log10 (R1/R2),
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled sound pressure level (SPL) from the
driven pile, and
R2 = the distance from the driven pile of the initial measurement
The recommended TL coefficient for most nearshore environments is
the, practical spreading value of 15. This value results in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions, which is the most appropriate
assumption for PSSA's proposed activity.
Using the practical spreading model, PSSA determined underwater
noise would fall below the behavioral effects threshold of 120 dB rms
for marine mammals at a maximum radial distance of 16,343 m for
vibratory pile driving the 36 and 48-inch diameter piles. This distance
determines the maximum Level B harassment zone for the project. Other
activities, including rock anchoring (DTH) and impact pile driving,
have smaller Level B harassment zones. All Level B harassment isopleths
are reported in Table 4 below and visualized in Figure 6 and Table 5 in
the IHA application. It should be noted that based on the geography of
Ward Cove, Tongass Narrows and the surrounding
[[Page 31152]]
islands, sound will not reach the full distance of the Level B
harassment isopleth. Generally, due to interaction with land, only a
thin slice of the possible area is ensonified and the maximum distance
before reaching land barriers is 3,645 m.
Table 4--Calculated Distances to Level B Harassment Isopleths During
Pile Installation and Removal
------------------------------------------------------------------------
Level B
Pile size isopleth
(m)
------------------------------------------------------------------------
Vibratory Pile Driving/Removal:
30-inch piles............................................. 6,213
36-inch piles............................................. 16,343
48-inch piles............................................. 16,343
Impact Pile Driving:
30-inch piles............................................. 3,744
36-inch piles............................................. 3,744
48-inch piles............................................. 3,744
Rock Anchoring (DTH):
36-inch piles............................................. 12,023
48-inch piles............................................. 12,023
------------------------------------------------------------------------
Level A Harassment Zones
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, we developed a User Spreadsheet that includes tools
to help predict a simple isopleth that can be used in conjunction with
marine mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced are typically going
to be overestimates of some degree, which may result in some degree of
overestimate of take by Level A harassment. However, these tools offer
the best way to predict appropriate isopleths when more sophisticated
3D modeling methods are not available, and NMFS continues to develop
ways to quantitatively refine these tools, and will qualitatively
address the output where appropriate. For stationary sources such as
impact/vibratory pile driving or drilling, NMFS User Spreadsheet
predicts the closest distance at which, if a marine mammal remained at
that distance the whole duration of the activity, it would not incur
PTS.
Inputs used in the User Spreadsheet (Table 5), and the resulting
isopleths are reported below (Table 6). Level A harassment thresholds
for impulsive sound sources (impact pile driving) are defined for both
SELcum (cumulative sound exposure levels) and Peak SPL, with the
threshold that results in the largest modeled isopleth for each marine
mammal hearing group used to establish the Level A harassment isopleth.
In this project, Level A harassment isopleths based on SELcum were
always larger than those based on Peak SPL.
Table 5--Parameters of Pile Driving and Drilling Activity Used in User Spreadsheet
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile Vibratory pile
driver driver Impact pile driver Impact pile driver Rock anchor (DTH) Rock anchor (DTH) Rock anchor (DTH) Rock anchor (DTH)
Equipment type (installation/ (installation of (30-inch steel (36 and 48-inch (36-inch steel (36-inch steel (48-inch steel (48-inch steel
removal of 30-inch 36 and 48-inch piles) steel piles) piles) piles) piles) piles)
steel piles) steel piles)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............ Non-impulsive, Non-impulsive, Impulsive, Non- Impulsive, Non- Continuous........ Impulsive......... Continuous........ Impulsive.
continuous. continuous. continuous. continuous.
Source Level.................... 161.9 SPL......... 168.2 SPL......... 186.7 SS * SEL.... 186.7 SS * SEL.... 166.2 SPL......... 164 SS * SEL...... 166.2 SPL......... 164 SS * SEL.
Weighting Factor Adjustment 2.5............... 2.5............... 2................. 2................. 2.5............... 2................. 2.5............... 2.
(kHz).
(a) Activity duration (time) (a) 0:40 (10 mins (a) 1:00 (30 mins (b) 40............ (b) 100........... (a) 8:00 (240 mins .................. (a) 5:00 (300 mins ..................
within 24 hours. * 4). * 2). * 2). * 1).
(b) Number of strikes per pile .................. .................. .................. .................. .................. (b)............... .................. (b).
(impact).
(c) Number of piles per day..... (c) 4............. (c) 2............. (c) 2............. (c) 2............. (c) 2............. (c) 2............. (c) 1............. (c) 1.
Propagation (xLogR)............. 15................ 15................ 15................ 15................ 15................ 15................ 15................ 15.
Distance of source level 10................ 10................ 11................ 11................ 10................ 10................ 10................ 10.
measurement (meters).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Data for all equipment types were for Propagation (xLogR) = 15 and distance of source level measurements was 10 meters.
* Largest isopleth distances for impact pile driving and DTH were all found when using SS SEL (see application for details) and SEL is the preferred metric.
The above input scenarios lead to a PTS isopleth distance (Level A
threshold) of 1.8 to 793 meters, depending on the marine mammal group
and scenario (Table 6).
Table 6--Calculated Distances to Level A Harassment Isopleths (m) During Pile Installation and Removal for Each
Hearing Group
----------------------------------------------------------------------------------------------------------------
Pile size Low frequency Mid frequency High frequency Phocid Otariid
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal:
30-inch piles............... 6 0.5 8.8 3.6 0.3
36-inch piles............... 20.6 1.8 30.5 12.5 0.9
48-inch piles............... 20.6 1.8 30.5 12.5 0.9
Impact Pile Driving:
30-inch piles............... 359.9 12.8 428.7 192.6 14
[[Page 31153]]
36-inch piles............... 663 23.6 789.7 354.8 25.8
48-inch piles............... 663 23.6 789.7 354.8 25.8
Rock Anchoring (DTH):
36-inch piles............... 665 24 793 356 26
48-inch piles............... 486 17 579 260 19
----------------------------------------------------------------------------------------------------------------
Note: A 10-meter shutdown zone will be implemented for all species and activity types to prevent direct injury
of marine mammals.
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of harbor seals, Dall's porpoise, and harbor
porpoises that will inform the take calculations. There is no density
data for any of the species near Ward Cove.
Harbor Seal
As discussed above anecdotal evidence suggests maximum group size
is up to three individuals in Ward Cove at one time. They are known to
occur year-round in the area with little seasonal variation in
abundance (Freitag (2017) as cited in 83 FR 37473, August 1, 2018) and
local experts estimate that there are about one to three harbor seals
in Tongass Narrows every day. To be conservative we will assume a group
size of five individuals in the project area each day.
Dall's Porpoise
Dall's porpoises are expected to only occur in the action area a
few times per year. Their relative rarity is supported by Jefferson et
al.'s (2019) presentation of historical survey data showing very few
sightings in the Ketchikan area and conclusion that Dall's porpoise
generally are rare in narrow waterways, like the Tongass Narrows. This
species is non-migratory; therefore, our occurrence estimates are not
dependent on season. We anticipate that one large Dall's porpoise pod
(15 individuals) (Freitag (2017), as cited in 83 FR37473, August 1,
2018) may be present in the project area once each month during
construction.
Harbor Porpoise
Harbor porpoises are non-migratory; therefore, our occurrence
estimates are not dependent on season. Freitag ((2017) as cited in 83
FR 37473, August 1, 2018) observed harbor porpoises in Tongass Narrows
zero to one time per month. Harbor porpoises observed in the project
vicinity typically occur in groups of one to five animals with an
estimated maximum group size of eight animals (83 FR 37473, August 1,
2018, Solstice 2018). For our impact analysis, we are considering a
group to consist of five animals, a value on the high end of the
typical group size. Based on Freitag (2017), and supported by the
reports of knowledgeable locals as described in the application for IHA
for Tongass Narrows (https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-department-transportation-ferry-berth-improvements), it is estimated that a maximum two groups (10) of harbor
porpoises would enter Tongass Narrows and potentially be exposed to
project related noise each of the four months of the project.
Steller's Sea Lion
Steller sea lion abundance in the Tongass Narrows area is not well
known. No systematic studies of Steller sea lions have been conducted
in or near the Tongass Narrows area. Steller sea lions are known to
occur year-round and local residents report observing Steller sea lions
about once or twice per week (Tongass Narrows IHA, 2019). Abundance
appears to increase during herring runs (March to May) and salmon runs
(July to September). Group sizes are generally 6 to 10 individuals
(Freitag (2017) as cited in 83 FR 37473, August 1, 2018) but have been
reported to reach 80 animals (HDR 2003). Tongass Narrows represents an
area of high anthropogenic activity that sea lions would normally
avoid, but at least three seafood processing plants and two fish
hatcheries may be attractants. Sea lions are generally unafraid of
humans when food sources are available. For these reasons, as we did
for the Tongass Narrows IHA (2019), we conservatively estimate that one
group of 10 Steller sea lions may be present in the project area each
day, but this occurrence rate may as much as double (20 Steller sea
lions per day) during periods of increased abundance associated with
the herring and salmon runs (March to May and July to September).
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate. As noted above, the
applicant only requested take of harbor seals, but we believe the
cryptic nature, small size, and dive duration of Dall's porpoise and
harbor porpoise, and abundance of Steller's sea lions, make it possible
that these three species could also be taken by entering the Level A or
Level B harassment zones before shutdown can occur (see below). We
describe how we estimated their take below and summarize it in Table 7.
It is important to note that PSSA proposes to implement a shutdown
of pile driving activity if any marine mammal other than these four
species is observed within the Level B harassment zone (see
Mitigation). Therefore, the take authorization is intended to provide
insurance against the event that marine mammals occur within Level A or
Level B harassment zones that cannot be fully observed by monitors. As
a result of this mitigation, we do not believe that Level A harassment
is a likely outcome for these three species. While the calculated Level
A harassment zone is as large as 793 m for DTH of 36-in steel piles
(ranging from 429 m for other impact driving scenarios), this requires
that an animal be present at that range for the full assumed duration
of pile strikes (expected to require multiple hours). Given the PSSA's
commitment to shut down upon observation of other marine mammals, and
the rarity of these animals inside Ward Cove where the Level A
harassment zones will be, we do not expect that any of these other
species would be present within a Level A harassment zone for
sufficient duration to actually experience PTS.
Harbor Seals
The take calculation was estimated based on the conservative group
size from above (five) multiplied by the number of expected groups per
day multiplied by the number of days of pile driving. Based on the
anecdotal
[[Page 31154]]
observations, it is conservatively estimated that two groups of five
harbor seals may occur within the Level B harassment zone every day
that pile driving may occur. Thus we estimate 5 animals in a group x 2
groups per day x 105 days = 1,050 times animals would occur within the
Level B harassment zone. The Level B harassment zones areas for trestle
construction and mooring dolphin construction differ in size because
more sound is expected to leak out of the cove into Tongass Narrows
when construction on the dolphins is toward the middle of the cove (see
Figure 6 of application). Nevertheless, it is expected that most of the
take will occur within Ward Cove (not Tongass Narrows) where the action
areas for trestle and dolphin construction overlap and are identical in
size, so take is not reduced despite the smaller area of trestle
effects.
The Level A harassment zone for harbor seals for impact pile
driving of 30-inch piles is 193 meters, for impact driving of 36 and
48-inch piles, the zone is 355 meters, and for the DTH scenarios it is
260-356 meters. For other pile driving activities the zones are much
smaller. Impact pile driving and DTH hammering would be shut down
before a harbor seal enters within 200 meters during these activities;
however, take by Level A harassment of harbor seals is requested
outside the 200 m shutdown zone for larger piles with zones exceeding
200 m. Impact driving would occur for no more than 10 minutes per day
on 20 days of construction and DTH would occur for no more than 48
minutes per day on 20 days of construction. As above we use group size
of five individuals and expect one group per day to be exposed in the
Level A harassment zone. Although mere ``exposure'' within the Level A
harassment zone is not indicative of an animal incurring auditory
injury due to the fact that injury results from accumulation of energy
over an assumed duration of exposure, we conservatively authorize 100
Level A harassment takes of harbor seal (5 animals in a group x 1
groups per day x 20 days = 100 animals). Because these animals exposed
in the Level A harassment zone duplicate those exposed in the Level B
zone, the authorized Level B harassment take is the number of Level B
harassment zone exposures minus the Level A take or 950 animals (1,050
- 100).
Dall's Porpoise
As discussed above we assume a single group of 15 individuals in
the project area each month. The take calculation was estimated based
on the conservative group size from above (15) multiplied by the number
of expected groups per month (1) multiplied by the number of months of
pile driving for the project (4). Thus we estimate a total of 60
individuals (15 x 1 x 4) may enter the Level B harassment zone. The
Level A harassment zones for Dall's porpoises for impact pile driving
of 30-inch piles is 429 meters, for impact driving of 36 and 48-inch
piles, the zone is 790 meters, and for the DTH scenarios it is 579-793
meters. Impact pile driving and DTH hammering would be shut down before
a Dall's porpoise enters within 200 meters during these activities;
however, take by Level A harassment of Dall's porpoises is requested
for outside the 200 m shutdown zone for those activities with zones
exceeding 200 m. We conservatively estimate that 15 individuals could
be exposed to levels above the Level A harassment threshold,
potentially in the form of one group entering and remaining in the
Level A harassment zone long enough to be exposed above the threshold,
or in the form of some smaller number being exposed in the same manner
on multiple days. Thus, we authorize 15 Level A harassment takes of
Dall's porpoise. Because these animals exposed in the Level A
harassment zone are assumed to be a subset of those predicted to be
exposed in the Level B zone, the authorized Level B harassment take is
the number of Level B harassment zone exposures minus the Level A take
or 45 animals (60 - 15).
Harbor Porpoise
As discussed above we assume a conservative group size of five
individuals occurring no more than twice in the project area each
month. The take calculation was estimated based on the group size from
above (5) multiplied by the number of expected groups per month (2)
multiplied by the number of months of pile driving for the project (4).
Thus we estimate a total of 40 individuals (5 x 2 x 4) may enter the
Level B harassment zone. The Level A harassment zones for harbor
porpoises for impact pile driving of 30-inch piles is 429 meters, for
impact driving of 36 and 48-inch piles, the zone is 790 meters, and for
the DTH scenarios it is 579-793 meters. Impact pile driving and DTH
hammering would be shut down before a harbor porpoise enters within 200
meters during these activities; however, take by Level A harassment of
harbor porpoises is requested for outside the 200 m shutdown zone for
those activities with zones exceeding 200 m. We conservatively estimate
three groups of five individuals could be exposed in the Level A
harassment zone. Thus, we authorize 15 Level A harassment takes of
harbor porpoises. Because these animals exposed in the Level A
harassment zone duplicate those exposed in the Level B zone, the
authorized Level B harassment take is the number of Level B harassment
zone exposures minus the Level A take or 25 animals (40 - 15).
Steller's Sea Lions
As described above, we anticipate that one large group (10
individuals) may be present in the Level B harassment zone once per
day. However, as discussed above, we anticipate that exposure may be as
much as twice this rate during March, April, May, July, August, and
September, due to the increased presence of prey. Therefore, we
anticipate that two large groups (20 individuals) may be present in the
Level B harassment zone each day during these months. We anticipate 25
days of activity during June when there are 10 Level B harassment zone
incursions per day and the rest of the project will be completed during
the months when there are 20 incursions per day. Therefore, we estimate
a total of 1,850 potential takes of Steller sea lions by Level B
harassment (i.e., 10 sea lions per day for 25 days (250) + 20 sea lions
per day for 80 days (1,600) = 1,850 sea lions).
Table 7--Authorized Amount of Taking, by Level A Harassment and Level B Harassment, by Species and Stock and
Percent of Stock Taken
----------------------------------------------------------------------------------------------------------------
Authorized take
-----------------------------------------------
Species Percent of
Level B Level A stock
----------------------------------------------------------------------------------------------------------------
Dall's porpoise (Phocoenoides dalli) Alaska Stock............... 45 15 <1
Harbor porpoise (Phocoena phocoena) Southeast Alaska Stock...... 25 15 4.1
[[Page 31155]]
Harbor seal (Phoca vitulina) Clarence Strait Stock.............. 950 100 3.8
Steller sea lion (Eumpetopia jubatus) Eastern DPS Stock......... 1,850 0 4.3
----------------------------------------------------------------------------------------------------------------
Effects of Specified Activities on Subsistence Uses of Marine Mammals
The availability of the affected marine mammal stocks or species
for subsistence uses may be impacted by this activity. The subsistence
uses that may be affected and the potential impacts of the activity on
those uses are described below. The information from this section is
analyzed to determine whether the necessary findings may be made in the
Unmitigable Adverse Impact Analysis and Determination section.
Subsistence harvest of harbor seals by Alaska Natives is not
prohibited by the MMPA. Since surveys of harbor seal subsistence
harvest in Alaska began in 1992, there have been declines in the number
of households hunting and harvesting seals in Southeast Alaska (Wolf et
al. 2013). Subsistence harvest data for the Clarence Strait stock
indicates an average annual harvest in the years 2004-2008 of 164
harbor seals (80 near Ketchikan) and an average annual harvest in the
years 2011-2012 of 40 harbor seals (summarized in Muto et al. 2016a
from Wolf et al. 2013). In 2008, two Steller sea lions were harvested
by Ketchikan-based subsistence hunters, but this is the only record of
sea lion harvest by residents of Ketchikan. In 2012, the community of
Ketchikan had an estimated subsistence take of 22 harbor seals (Wolf et
al. 2013). This is the most recent data for Ketchikan. The ADF&G has
not recorded harvest of cetaceans in the area (ADF&G 2018). Hunting
usually occurs in October and November (ADF&G 2009), but there are also
records of relatively high harvest in May (Wolfe et al. 2013).
In June 2019, attempts were made by PSSA to contact the Alaska
Harbor Seal Commission, the Alaska Sea Otter and Steller Sea Lion
Commission, and the Ketchikan Indian Community (KIC, Federal-recognized
Tribe) to discuss this project. The Alaska Harbor Seal Commission is
currently not operational. Comments were not received from the Alaska
Sea Otter and Steller Sea Lion Commission. PSSA met with KIC and KIC
submitted comments for the Army Corps of Engineers permit for this
project. They did not express concerns about subsistence hunting.
Construction activities at the project site would be expected to
cause only short term, non-lethal disturbance of marine mammals.
Construction activities are localized and temporary in the previously
developed Ward Cove, mitigation measures will be implemented to
minimize disturbance of marine mammals in the action area, and, the
project will not result in significant changes to availability of
subsistence resources. Impacts on the abundance or availability of
either species to subsistence hunters in the region are thus not
anticipated.
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses. NMFS regulations require applicants for incidental
take authorizations to include information about the availability and
feasibility (economic and technological) of equipment, methods, and
manner of conducting the activity or other means of effecting the least
practicable adverse impact upon the affected species or stocks and
their habitat (50 CFR 216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat, as
well as subsistence uses. This considers the nature of the potential
adverse impact being mitigated (likelihood, scope, range). It further
considers the likelihood that the measure will be effective if
implemented (probability of accomplishing the mitigating result if
implemented as planned), the likelihood of effective implementation
(probability implemented as planned), and;
(2) the practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
The following mitigation measures are in the IHA:
Schedule: Pile driving or removal must occur during
daylight hours. If poor environmental conditions restrict visibility
(e.g., from excessive wind or fog, high Beaufort state), pile
installation would be delayed;
Pile Driving Delay/Shut-Down: For use of in-water heavy
machinery/vessel (e.g., dredge), PSSA must implement a minimum shutdown
zone of 10 m radius around the pile/vessel. For vessels, PSSA must
cease operations and reduce vessel speed to the minimum required to
maintain steerage and safe working conditions. In addition, if an
animal comes within the shutdown zone (see Table 8) of a pile being
driven or removed, PSSA would shut down. The shutdown zone would only
be reopened if they observe the animal exiting the zone or when a
marine mammal has not been observed within the shutdown zone for a 15-
minute period. If DTH or pile driving is stopped, pile installation
would not commence if any marine mammals are observed anywhere within
the Level A harassment zone. Pile driving activities must only be
conducted during daylight hours when it is possible to visually monitor
for marine mammals. If a species for which authorization has not been
granted, or if a species for which authorization has been granted but
the authorized takes are met, PSSA must delay or shut-down pile driving
if the marine mammal approaches or is
[[Page 31156]]
observed within the Level A and/or B harassment zones.
Table 8--Shutdown and Monitoring Zones for Each Activity Type and Stock
----------------------------------------------------------------------------------------------------------------
Harbor
Harbor seal porpoise, Steller sea Other marine Level B
Pile size shutdown Dall's porpoise lion shutdown mammal monitoring
distance (m) shutdown distance (m) shutdown zone (m)
distance (m) distance (m)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal:
30-inch piles.............. 10 10 10 3,645 3,645
36-inch piles.............. 15 40 10 3,645 3,645
48-inch piles.............. 15 40 10 3,645 3,645
Impact Pile Driving:
30-inch piles.............. 200 200 20 3,645 3,645
36-inch piles.............. 200 200 30 3,645 3,645
48-inch piles.............. 200 200 30 3,645 3,645
Rock Anchoring (DTH):
36-inch piles.............. 200 200 30 3,645 3,645
48-inch piles.............. 200 200 20 3,645 3,645
All Other Activities:
Any activity............... 10 10 10 N/A N/A
----------------------------------------------------------------------------------------------------------------
Note: A Level A monitoring zone is implemented for DTH and impact pile driving of 30 to 48-inch diameter piles
out to the extent of the Level A harassment zone (793 m). Level B monitoring zone (for the four species with
authorized take) and other marine mammal shutdown distance of 3,645 m reflects the farthest distance before
sound is inhibited by land.
Soft-start: For all impact pile driving, a ``soft start''
technique must be used at the beginning of each pile installation day,
or if pile driving has ceased for more than 30 minutes, to allow any
marine mammal that may be in the immediate area to leave before
hammering at full energy. The soft start requires PSSA to provide an
initial set of three strikes from the impact hammer at reduced energy,
followed by a 30 second waiting period, then two subsequent three-
strike sets. If any marine mammal is sighted within the Level A
shutdown zone prior to pile-driving, or during the soft start, PSSA
must delay pile-driving until the animal is confirmed to have moved
outside and is on a path away from the Level A harassment zone or if 15
minutes have elapsed since the last sighting;
Sediment control: All material that comes out of the top
of the pile during pile driving (drill cutting discharge) must be
collected on a barge and transported to a permitted upland location for
disposal. Pile driving, temporary pile removal, and collection of
excavated material operations must be surrounded by a 50-feet (15 m)
deep silt curtain; and
Other best management practices: PSSA will drive all piles
with a vibratory hammer to the maximum extent possible (i.e., until a
desired depth is achieved or to refusal) prior to using an impact
hammer. PSSA will also use the minimum hammer energy needed to safely
install the piles.
Based on our evaluation of the applicant's proposed measures, NMFS
has determined that the mitigation measures provide the means effecting
the least practicable 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 stock for subsistence uses.
Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that 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
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 in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Visual Monitoring
Monitoring must be conducted 30 minutes before, during, and 30
minutes after pile driving and removal activities. In addition,
observers shall record all incidents of marine mammal occurrence,
regardless of distance from activity, and shall document any behavioral
reactions in concert with distance from piles being driven or removed.
Pile driving activities include the time to install a single pile or
series
[[Page 31157]]
of piles, as long as the time elapsed between uses of the pile driving
equipment is no more than 30 minutes.
Four PSO's will be used to monitor the project and their locations
are shown in Figure 12 of the monitoring plan. A primary PSO must be
placed near the project site in Ward Cove where pile driving would
occur. The primary purpose of this observer is to monitor and implement
the Level A shutdown and monitoring zones. Three additional PSOs must
be positioned in order to focus on monitoring the Level B harassment
and other species shutdown zone. PSOs would scan the waters using
binoculars, and/or spotting scopes, and would use a handheld GPS or
range-finder device to verify the distance to each sighting from the
project site. All PSOs would be trained in marine mammal identification
and behaviors and are required to have no other project-related tasks
while conducting monitoring. The following measures also apply to
visual monitoring:
(1) Monitoring must be conducted by NMFS-approved qualified
observers, who will be placed at the best vantage point(s) practicable
to monitor for marine mammals and implement shutdown/delay procedures
when applicable by calling for the shutdown to the hammer operator.
Qualified observers are trained biologists, with the following minimum
qualifications:
(a) Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
(b) Advanced education in biological science or related field
(undergraduate degree or higher required);
(c) Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience);
(d) Experience or training in the field identification of marine
mammals, including the identification of behaviors;
(e) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
(f) Writing skills sufficient to prepare a report of observations
including but not limited to the number and species of marine mammals
observed; dates and times when in-water construction activities were
conducted; dates and times when in-water construction activities were
suspended to avoid potential incidental injury from construction sound
of marine mammals observed within a defined shutdown zone; and marine
mammal behavior; and
(g) Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary; and
(2) PSSA shall submit observer Curriculum vitae for approval by
NMFS.
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities, or 60 days prior to a requested date of issuance of any
future IHAs for projects at the same location, whichever comes first.
It will include an overall description of work completed, a narrative
regarding marine mammal sightings, and associated marine mammal
observation data sheets. Specifically, the report must include:
Dates and times (begin and end) of all marine mammal
monitoring;
Construction activities occurring during each daily
observation period, including how many and what type of piles were
driven or removed and by what method (i.e., impact or vibratory);
Weather parameters and water conditions during each
monitoring period (e.g., wind speed, percent cover, visibility, sea
state);
The number of marine mammals observed, by species,
relative to the pile location and if pile driving or removal was
occurring at time of sighting;
Age and sex class, if possible, of all marine mammals
observed;
PSO locations during marine mammal monitoring;
Distances and bearings of each marine mammal observed to
the pile being driven or removed for each sighting (if pile driving or
removal was occurring at time of sighting);
Description of any marine mammal behavior patterns during
observation, including direction of travel and estimated time spent
within the Level A and Level B harassment zones while the source was
active;
Number of individuals of each species (differentiated by
month as appropriate) detected within the monitoring zone, and
estimates of number of marine mammals taken, by species (a correction
factor may be applied to total take numbers, as appropriate);
Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting behavior of the animal, if
any;
Description of attempts to distinguish between the number
of individual animals taken and the number of incidences of take, such
as ability to track groups or individuals; and
An extrapolation of the estimated takes by Level B
harassment based on the number of observed exposures within the Level B
harassment zone and the percentage of the Level B harassment zone that
was not visible, when applicable.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, PSSA shall report the
incident to the Office of Protected Resources (OPR), NMFS and to the
regional stranding coordinator as soon as feasible. If the death or
injury was clearly caused by the specified activity, the IHA-holder
must immediately cease the specified activities until NMFS is able to
review the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of the IHA. The IHA-holder must not resume their activities until
notified by NMFS. The report must include the following information:
Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
Species identification (if known) or description of the
animal(s) involved;
Condition of the animal(s) (including carcass condition if
the animal is dead);
Observed behaviors of the animal(s), if alive;
If available, photographs or video footage of the
animal(s); and
General circumstances under which the animal was
discovered.
Negligible Impact Analysis and Determination
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-
[[Page 31158]]
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, 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 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's 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 environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
Pile driving and drilling activities have the potential to disturb
or displace marine mammals and, infrequently, cause low levels of
permanent hearing impairment. Specifically, the project activities may
result in take, in the form of Level A harassment and Level B
harassment from underwater sounds generated from pile driving and
removal and DTH. Potential takes could occur if individuals are present
in the ensonified zone when these activities are underway.
The takes from Level A and Level B harassment will be due to
potential behavioral disturbance, TTS, and PTS. No mortality is
anticipated given the nature of the activity and measures designed to
minimize the possibility of injury to marine mammals. The potential for
harassment is minimized through the construction method and the
implementation of the planned mitigation measures (see Mitigation
section).
The Level A harassment zones identified in Table 8 are based upon
an animal exposed to impact pile driving multiple piles per day.
Considering duration of impact driving each pile (up to 3 minutes) and
breaks between pile installations (to reset equipment and move pile
into place), this means an animal would have to remain within the area
estimated to be ensonified above the Level A harassment threshold for
multiple hours. This is highly unlikely given marine mammal movement
throughout the area. If an animal was exposed to accumulated sound
energy, the resulting PTS would likely be small (e.g., PTS onset) at
lower frequencies where pile driving energy is concentrated.
Behavioral responses of marine mammals to pile driving at the
project site, if any, are expected to be mild and temporary. Marine
mammals within the Level B harassment zone may not show any visual cues
they are disturbed by activities (as noted during modification to the
Kodiak Ferry Dock) or could become alert, avoid the area, leave the
area, or display other mild responses that are not observable such as
changes in vocalization patterns. Given the short duration of noise-
generating activities per day and that pile driving and removal will
occur across 4-5 months, any harassment would be temporary. There are
no other areas or times of known biological importance for any of the
affected species.
In addition, it is unlikely that minor noise effects in a small,
localized area of habitat would have any effect on the stocks' ability
to recover. In combination, we believe that these factors, as well as
the available body of evidence from other similar activities,
demonstrate that the potential effects of the specified activities will
have only minor, short-term effects on individuals that would not
impact the fitness of any individuals. The specified activities are not
expected to impact rates of recruitment or survival and will therefore
not result in population-level impacts.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect the species or stock through
effects on annual rates of recruitment or survival:
No serious injury or mortality is anticipated or
authorized;
Authorized Level A harassment will be small amounts and of
low degree;
PSSA will implement mitigation measures such as vibratory
driving piles to the maximum extent practicable, soft-starts, silt
curtains, removal of potentially contaminated sediments, and shut
downs; and
Monitoring reports from similar work in Alaska have
documented little to no effect on individuals of the same species
impacted by the specified activities.
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 proposed monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
the proposed activity will have a negligible impact on all affected
marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Section 101(a)(5)(D) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers and so, in practice, where estimated numbers are
available, NMFS compares the number of individuals taken to the most
appropriate estimation of abundance of the relevant species or stock in
our determination of whether an authorization is limited to small
numbers of marine mammals. Additionally, other qualitative factors may
be considered in the analysis, such as the temporal or spatial scale of
the activities.
The amount of take NMFS proposes to authorize is less than one
third for all stocks (in fact, less than 5 percent for harbor seals,
Steller sea lions, and harbor porpoises). The Alaska stock of Dall's
porpoise has no official NMFS abundance estimate as the most recent
estimate is greater than eight years old. Nevertheless, the most recent
estimate was 83,400 animals and it is highly unlikely this number has
drastically declined. Therefore, the 60 authorized takes of this stock
clearly represent small numbers of this stock. These are all likely
conservative estimates because they assume all takes are of different
individual animals which is likely not the case. Some individuals may
return across multiple days but have been included as separate
instances of take in our estimates.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS finds that small numbers of
marine mammals will be taken relative to the population size of the
affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
In order to issue an IHA, NMFS must find that the specified
activity will not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
That is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid
[[Page 31159]]
hunting areas; (ii) Directly displacing subsistence users; or (iii)
Placing physical barriers between the marine mammals and the
subsistence hunters; and (2) That cannot be sufficiently mitigated by
other measures to increase the availability of marine mammals to allow
subsistence needs to be met.
As discussed above in the Effects of Specified Activities on
Subsistence Uses of Marine Mammals section, subsistence harvest of
harbor seals and other marine mammals is rare in the area and local
subsistence users have not expressed concern about this project. All
project activities will take place within the industrial area of
Tongass Narrows and Ward Cove immediately adjacent to Ketchikan where
subsistence activities do not generally occur. The project also will
not have an adverse impact on the availability of marine mammals for
subsistence use at locations farther away, where these construction
activities are not expected to take place. Some minor, short-term
harassment of the harbor seals could occur, but any effects on
subsistence harvest activities in the region will be minimal, and not
have an adverse impact.
Based on the effects and location of the specified activity, and
the mitigation and monitoring measures, NMFS has determined that there
will not be an unmitigable adverse impact on subsistence uses from
PSSA's planned activities.
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 review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment. This action
is consistent with categories of activities identified in Categorical
Exclusion B4 (IHAs with no anticipated serious injury or mortality) of
the Companion Manual for NOAA Administrative Order 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has determined that the
issuance of the IHA qualifies to be categorically excluded from further
NEPA review.
Endangered Species Act (ESA)
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally, in this case with the Alaska Region Protected
Resources Division Office, whenever we propose to authorize take for
endangered or threatened species.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Authorization
NMFS has issued an IHA to PSSA for the potential harassment of
small numbers of three marine mammal species incidental to the Ward
Cove Cruise Ship Dock project near Ketchikan, Alaska, provided the
previously mentioned mitigation, monitoring and reporting requirements
are incorporated.
Dated: May 18, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2020-11116 Filed 5-21-20; 8:45 am]
BILLING CODE 3510-22-P