[Federal Register Volume 85, Number 29 (Wednesday, February 12, 2020)]
[Notices]
[Pages 7952-7977]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-02662]
[[Page 7952]]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XR078]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Marine Site Characterization
Surveys Off of Massachusetts, Rhode Island, Connecticut, and New York
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from Vineyard Wind, LLC (Vineyard
Wind) for authorization to take marine mammals incidental to marine
site characterization surveys of Massachusetts in the areas of the
Commercial Lease of Submerged Lands for Renewable Energy Development on
the Outer Continental Shelf (OCS-A 0501 and OCS-A 0522) and along
potential submarine cable routes to a landfall location in
Massachusetts, Rhode Island, Connecticut, and New York. Pursuant to the
Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its
proposal to issue an incidental harassment authorization (IHA) to
incidentally take marine mammals during the specified activities. NMFS
is also requesting comments on a possible one-year renewal that could
be issued under certain circumstances and if all requirements are met,
as described in Request for Public Comments at the end of this notice.
NMFS will consider public comments prior to making any final decision
on the issuance of the requested MMPA authorizations and agency
responses will be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than March
13, 2020.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Physical comments should be sent to
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments
should be sent to [email protected].
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments received electronically, including
all attachments, must not exceed a 25-megabyte file size. Attachments
to electronic comments will be accepted in Microsoft Word or Excel or
Adobe PDF file formats only. All comments received are a part of the
public record and will generally be posted online at
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable without change.
All personal identifying information (e.g., name, address) voluntarily
submitted by the commenter may be publicly accessible. Do not submit
confidential business information or otherwise sensitive or protected
information.
FOR FURTHER INFORMATION CONTACT: Robert Pauline, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the applications
and supporting documents, as well as a list of the references cited in
this document, may be obtained by visiting the internet at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. 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 such 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 such takings are set forth.
The definitions of all applicable MMPA statutory terms cited above
are included in the relevant sections below.
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 our proposed action (i.e., the promulgation of
regulations and subsequent issuance of incidental take authorization)
and alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 of the Companion Manual for NAO 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
preliminarily determined that the proposed action qualifies to be
categorically excluded from further NEPA review.
Information in Vineyard Wind's application and this notice
collectively provide the environmental information related to proposed
issuance of these regulations and subsequent incidental take
authorization for public review and comment. We will review all
comments submitted in response to this notice prior to concluding our
NEPA process or making a final decision on the request for incidental
take authorization.
Summary of Request
On October 24, 2019, NMFS received a request from Vineyard Wind for
an IHA to take marine mammals incidental to marine site
characterization surveys offshore of Massachusetts in the areas of the
Commercial Lease of Submerged Lands for Renewable Energy Development on
the Outer Continental Shelf (OCS-A 0501 and OCS-A 0522) and along
potential submarine offshore export cable corridors (OECC) to a
landfall locations in Massachusetts, Rhode Island, Connecticut, and New
York. NMFS deemed that request to be adequate and complete on January
7, 2020. Vineyard Wind's request is for the take of 14 marine mammal
species by Level B harassment that would occur over the course of up to
365 calendar
[[Page 7953]]
days. Neither Vineyard Wind nor NMFS expects serious injury or
mortality to result from this activity and the activity is expected to
last no more than one year, therefore, an IHA is appropriate.
Description of the Proposed Activity
Overview
Vineyard Wind proposes to conduct high-resolution geophysical (HRG)
surveys in support of offshore wind development projects in the areas
of Commercial Lease of Submerged Lands for Renewable Energy Development
on the Outer Continental Shelf (#OCS-A 0501 and #OCS-A 0522) (Lease
Areas) and along potential submarine cable routes to landfall locations
in Massachusetts, Rhode Island, Connecticut, and New York.
The purpose of the marine site characterization surveys is to
obtain a baseline assessment of seabed/sub-surface soil conditions in
the Lease Area and cable route corridors to support the siting of
potential future offshore wind projects. Underwater sound resulting
from Vineyard Wind's proposed site characterization surveys has the
potential to result in incidental take of marine mammals in the form of
behavioral harassment.
Dates and Duration
The estimated duration of the activity is expected to be up to 365
survey days between April 1, 2020 and March 31, 2021. This schedule is
based on 24-hour operations and includes potential down time due to
inclement weather. With up to eight survey vessels operating
concurrently, a maximum of 736 vessels days are anticipated.
Specific Geographic Region
Vineyard Wind's survey activities would occur in the Northwest
Atlantic Ocean within Federal waters. The area includes Lease Area OCS-
A 0501, located approximately 24 kilometers (km) (13 nautical miles
[nm]) from the southeast corner of Martha's Vineyard and Lease Area
OCS-A 0522, located approximately 46 km (25 nm) south of Nantucket.
Additionally, OECC routes may also be surveyed within the area depicted
in Figure 1.
Water depths across the lease areas range from approximately 35 to
63 meters (m) (115 to 207 feet [ft]); potential offshore export cable
corridor (OECC) routes in the Project Area will be evaluated and will
extend from the lease areas to shallow water areas near potential
landfall locations in Massachusetts, Rhode Island, Connecticut, and New
York as shown in Figure 1.
HRG survey activities south of Cape Cod are anticipated to begin on
April 1, 2020 and will last for up to one year. HRG survey activities
proposed for north and northeast of Cape Cod will be conducted
exclusively during the months of August and September when North
Atlantic right whales (NARWs; Eubalaena glacialis) are not anticipated
to be present (Roberts et al. 2018).
[GRAPHIC] [TIFF OMITTED] TN12FE20.001
[[Page 7954]]
Detailed Description of the Specified Activities
Vineyard Wind's proposed marine site characterization surveys
include high-resolution geophysical (HRG) survey activities. Water
depths in the Lease Areas range from 35 to 63 m (115 to 207 ft). Water
depths along the potential OECC routes range from 5 to greater than 200
m (16 to >656 ft). The OECC routes will extend from the lease areas to
shallow water areas near potential landfall locations in Massachusetts,
Rhode Island, Connecticut, and New York.
HRG equipment will be deployed from multiple vessels acquiring data
concurrently within the HRG Project Area (Figure 1). HRG survey
activities south of Cape Cod are anticipated to begin on April 1, 2020
and will last for up to 365 calendar days with a total of 736 vessel
days. HRG survey activities proposed for north and northeast of Cape
Cod will be conducted exclusively during the months of August and
September when North Atlantic right whales (NARWs; Eubalaena glacialis)
are not anticipated to be present (Nichols et al. 2008). For the
purpose of this IHA the Lease Areas and submarine cable corridor are
collectively termed the Project Area.
Geophysical survey activities are anticipated to include as many as
eight survey vessels which may be operating concurrently. Survey
vessels would maintain a speed of approximately 4 knots (kn) while
transiting survey lines and each vessel would cover approximately 100
km per day. The proposed HRG survey activities are described below.
Geophysical Survey Activities
Vineyard Wind has proposed that HRG survey operations would be
conducted continuously 24 hours per day. Based on 24-hour operations,
the estimated duration of the geophysical survey activities would be up
to 365 calendar days with a total of 736 total survey vessel days
(including estimated weather down time). As many as eight survey
vessels may be used concurrently during Vineyard Wind's proposed
surveys. The geophysical survey activities proposed by Vineyard Wind
would include the following:
Shallow Penetration Sub-bottom Profilers (SBP; Chirps) to
map the near-surface stratigraphy (top 0 to 5 m (0 to 16 ft) of
sediment below seabed). A chirp system emits sonar pulses that increase
in frequency over time. The pulse length frequency range can be
adjusted to meet project variables. Typically mounted on the hull of
the vessel or from a side pole.
Medium Penetration SBPs (Boomers) to map deeper subsurface
stratigraphy as needed. A boomer is a broad-band sound source operating
in the 3.5 Hz to 10 kHz frequency range. This system is typically
mounted on a sled and towed behind the vessel.
Medium Penetration SBPs (Sparkers) to map deeper
subsurface stratigraphy as needed. Sparkers create acoustic pulses from
50 Hz to 4 kHz omni-directionally from the source that can penetrate
several hundred meters into the seafloor. Typically towed behind the
vessel with adjacent hydrophone arrays to receive the return signals.
Parametric SBPs, also called sediment echosounders, for
providing high data density in sub-bottom profiles that are typically
required for cable routes, very shallow water, and archaeological
surveys. Typically mounted on the hull of the vessel or from a side
pole.
Multibeam Echosounders (MBESs) to determine water depths
and general bottom topography. MBES sonar systems project sonar pulses
in several angled beams from a transducer mounted to a ship's hull. The
beams radiate out from the transducer in a fan-shaped pattern
orthogonally to the ship's direction.
Ultra-Short Baseline (USBL) Positioning and Global
Acoustic Positioning System (GAPS) to provide high accuracy ranges by
measuring the time between the acoustic pulses transmitted by the
vessel transceiver and the equipment transponder necessary to produce
the acoustic profile. It is a two-component system with a hull or pole
mounted transceiver and one to several transponders either on the
seabed or on the equipment.
Side-scan Sonar (SSS) for seabed sediment classification
purposes and to identify natural and man-made acoustic targets on the
seafloor. The sonar device emits conical or fan-shaped pulses down
toward the seafloor in multiple beams at a wide angle, perpendicular to
the path of the sensor through the water. The acoustic return of the
pulses is recorded in a series of cross-track slices, which can be
joined to form an image of the sea bottom within the swath of the beam.
They are typically towed beside or behind the vessel or from an
autonomous vehicle.
Table 1 identifies the representative survey equipment that may be
used in support of proposed geophysical survey activities that operate
below 180 kilohertz (kHz) and have the potential to cause acoustic
harassment to marine species, including marine mammals, and therefore
require the establishment and monitoring of exclusion zones.
HRG surveys are expected to use several equipment types
concurrently in order to collect multiple aspects of geophysical data
along one transect. Selection of equipment combinations is based on
specific survey objectives.
Table 1--Summary of Geophysical Survey Equipment Proposed for Use by Vineyard Wind
--------------------------------------------------------------------------------------------------------------------------------------------------------
Operating Peak source Pulse
HRG equipment category Specific HRG equipment frequency Beam width Source level level (dB re duration Repetition
(kHz) ([deg]) (dB rms) 1 [mu]Pa m) (ms) rate (Hz)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shallow subbottom profiler.............. EdgeTech Chirp 216........ 2-10 65 178 182 2 3.75
Innomar SES 2000 Medium... 85-115 2 241 247 2 40
Deep seismic profiler................... Applied Acoustics AA251 0.2-15 180 205 212 0.9 2
Boomer.
GeoMarine Geo Spark 2000 0.25-5 180 206 214 2.8 1
(400 tip).
Underwater positioning (USBL)........... SonarDyne Scout Pro....... 35-50 180 188 191 Unknown Unknown
ixBlue Gaps............... 20-32 180 191 194 1 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
The deployment of HRG survey equipment, including the equipment
anticipated for use during Vineyard Wind's proposed activity, produces
sound in the marine environment that has the potential to result in
harassment of marine mammals. However, sound propagation in water is
dependent on several factors including operating mode, frequency and
beam direction of the HRG equipment; thus, potential impacts to marine
mammals from HRG
[[Page 7955]]
equipment are driven by the specification of individual HRG sources.
The specifications of the potential equipment proposed for use during
HRG survey activities (Table 1) were analyzed to determine which types
of equipment would have the potential to result in harassment of marine
mammals.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see ``Proposed
Mitigation'' and ``Proposed Monitoring and Reporting'').
Description of Marine Mammals in the Area of Specified Activity
Sections 3 and 4 of the IHA 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' Stock Assessment Reports (SARs;
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'
website (www.fisheries.noaa.gov/find-species).
Table 2 lists all species with expected potential for occurrence in
the Project Area 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 (2016). 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 Project Area.
NMFS' 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' U.S. Atlantic SARs. All values presented in Table 2 are the most
recent available at the time of publication and are available in either
the 2018 Atlantic and Gulf of Mexico Marine Mammal Stock Assessments
(Hayes et al., 2019a), available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region or and draft 2019 Atlantic and Gulf of Mexico Marine
Mammal Stock Assessments (Hayes et al. 2019b) available online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports.
Table 2--Marine Mammals Known To Occur in the Project Area That May Be Affected by Vineyard Wind's Proposed Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock Strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
North Atlantic Right whale...... Eubalaena glacialis.... Western North Atlantic E/D; Y 409 \4\ (0; 445; 2017) 0.9 5.56
(WNA).
Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeangliae. Gulf of Maine.......... -/-; N 1,396 (0; 1,380; See 22 12.15
SAR).
Fin whale....................... Balaenoptera physalus.. WNA.................... E/D; Y 7,418 (0.25; 6,029; 12 2.35
See SAR).
Sei whale....................... Balaenoptera borealis.. Nova Scotia............ E/D; Y 6,292 (1.015; 3,098; 6.2 1
See SAR)236.
Minke whale..................... Balaenoptera Canadian East Coast.... -/-; N 24,202 (0.3; 18,902; 1,189 8
acutorostrata. See SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
Sperm whale..................... Physeter macrocephalus. NA..................... E; Y 4,349 (0.28; 3,451; 6.9 0
See SAR).
Family Delphinidae:
Long-finned pilot whale......... Globicephala melas..... WNA.................... -/-; Y 5,636 (0.63; 3,464)... 35 38
Bottlenose dolphin.............. Tursiops spp........... WNA Offshore........... -/-; N 62,851 (0.23; 51,914; 591 28
Ses SAR).
Common dolphin.................. Delphinus delphis...... WNA.................... -/-; N 172,825 (0.21; 1,452 419
145,216; See SAR).
Atlantic white-sided dolphin.... Lagenorhynchus acutus.. WNA.................... -/-; N 92,233 (0.71; 54,433; 544 26
See SAR).
Risso's dolphin................. Grampus griseus........ WNA.................... -/-; N 35,493 (0.19; 30,289; 303 54.3
See SAR).
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Gulf of Maine/Bay of -/-; N 95,543 (0.31; 74,034; 851 217
Fundy. See SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Gray seal....................... Halichoerus grypus..... WNA.................... -/-; N 27,131 (0.19; 23,158). 1,389 5,688
Harbor seal..................... Phoca vitulina......... WNA.................... -/-; N 75,834 (0.15; 66,884). 345 333
--------------------------------------------------------------------------------------------------------------------------------------------------------
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-assessment-reports-region/. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
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.
4 For the North Atlantic right whale the best available abundance estimate is derived from the 2018 North Atlantic Right Whale Consortium 2019 Annual
Report Card (Pettis et al., 2012).
As described below, 14 species (with 14 managed stocks) temporally
and spatially co-occur with the activity to the degree that take is
reasonably likely to occur, and we have proposed authorizing it.
The following subsections provide additional information on the
biology, habitat use, abundance, distribution, and the existing threats
to the non-ESA-listed and ESA-listed marine mammals that are both
common in the waters of the outer continental shelf (OCS) of Southern
New England and have the
[[Page 7956]]
likelihood of occurring, at least seasonally, in the Project Area.
North Atlantic Right Whale
The North Atlantic right whale ranges from the calving grounds in
the southeastern United States to feeding grounds in New England waters
and into Canadian waters (Waring et al., 2017). Surveys indicate that
there are seven areas where NARWs congregate seasonally: the coastal
waters of the southeastern U.S., the Great South Channel, Jordan Basin,
Georges Basin along the northeastern edge of Georges Bank, Cape Cod and
Massachusetts Bays, the Bay of Fundy, and the Roseway Basin on the
Scotian Shelf (Hayes et al. 2018). NOAA Fisheries has designated two
critical habitat areas for the NARW under the ESA: The Gulf of Maine/
Georges Bank region, and the southeast calving grounds from North
Carolina to Florida.
Aerial surveys indicated that right whales were consistently
detected in or near the Lease Areas and surrounding survey areas during
the winter and spring seasons. It appears that right whales begin to
arrive in this area in December and remain in the area through at least
April. Acoustic detections of right whales occurred during all months
of the year, although the highest number of detections typically
occurred between December and late May. Data indicate that right whales
occur at elevated densities in the Project Area south and southwest of
Martha's Vineyard in the spring (March-May) and south of Nantucket
during winter (December-February) (Roberts et al. 2018; Leiter et al.
2017; Kraus et al. 2016). Consistent aggregations of right whales
feeding and possibly mating within or close to these specific areas is
such that they have been considered right whale ``hotspots'' (Leiter et
al. 2017; Kraus et al. 2016). Additionally, numerous Dynamic Management
Areas (DMAs) have been established in these areas in recent years. As
of this writing a DMA has been established approximately 31 miles due
south of Nantucket. Although there is variability in right whale
distribution patterns among years, and some aggregations appear to be
ephemeral, an analysis of hot spots suggests that there is some
regularity in right whale use of the Lease Areas and surrounding
Project Area (Kraus et al. 2016).
NMFS' regulations at 50 CFR part 224.105 designated nearshore
waters of the Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal
Management Areas (SMA) for right whales in 2008. SMAs were developed to
reduce the threat of collisions between ships and right whales around
their migratory route and calving grounds. All vessels greater than
19.8 m (65 ft) in overall length must operate at speeds of 10 knots
(5.1 m/s) or less within these areas during specific time periods. The
Block Island Sound SMA overlaps with the southern portion of Lease Area
OCS-A 0501 and is active between November 1 and April 30 each year. The
Great South Channel SMA lies to the northeast of Lease Area OCS-A 0501
and is active April 1 to July 31. Potential OECC routes lie within the
Cape Cod Bay SMA, which is active between January 1 to May 15, and the
Off Race Point SMA, which is active from March 1 to April 30.
NOAA Fisheries may also establish DMAs when and where NARWs are
sighted outside SMAs. DMAs are generally in effect for two weeks.
During this time, vessels are encouraged to avoid these areas or reduce
speeds to 10 knots (5.1 m/s) or less while transiting through these
areas.
The lease areas included in the HRG Project Area are encompassed by
a right whale Biologically Important Area (BIA) for migration from
March to April and from November to December (LaBrecque et al. 2015).
Designated feeding BIAs occur in Cape Cod Bay from February to April
and northeast of the Lease areas from April to June. A map showing
designated BIAs is available at: https://cetsound.noaa.gov/biologically-important-area-map. Additionally, a small part of the
proposed Project Area northeast of Cape Cod includes designated right
whale critical habitat.
The western North Atlantic population demonstrated overall growth
of 2.8 percent per year from 1990 to 2010, despite a decline in 1993
and no growth between 1997 and 2000 (Pace et al. 2017). However, since
2010 the population has been in decline, with a 99.99 percent
probability of a decline of just under 1 percent per year (Pace et al.
2017). Between 1990 and 2015, calving rates varied substantially, with
low calving rates coinciding with all three periods of decline or no
growth (Pace et al. 2017). In 2018, no new North Atlantic right whale
calves were documented in their calving grounds; this represented the
first time since annual NOAA aerial surveys began in 1989 that no new
right whale calves were observed. However, in 2019 at least seven right
whale calves were identified while six calves have been recorded in
2020. Unfortunately, one of the calves was struck by a vessel and
suffered serious head injuries. It is not likely to survive. Data
indicates that the number of adult females fell from 200 in 2010 to 186
in 2015 while males fell from 283 to 272 in the same time frame (Pace
et al., 2017). In addition, elevated North Atlantic right whale
mortalities have occurred since June 7, 2017. A total of 30 confirmed
dead stranded whales (21 in Canada; 9 in the United States), have been
documented to date. This event has been declared an Unusual Mortality
Event (UME), with human interactions (i.e., fishery-related
entanglements and vessel strikes) identified as the most likely cause.
More information is available online at: https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2019-north-atlantic-right-whale-unusual-mortality-event (accessed January 9,
2020).
Humpback Whale
Humpback whales are found worldwide in all oceans. Humpback whales
were listed as endangered under the Endangered Species Conservation Act
(ESCA) in June 1970. In 1973, the ESA replaced the ESCA, and humpbacks
continued to be listed as endangered. NMFS recently evaluated the
status of the species, and on September 8, 2016, NMFS divided the
species into 14 distinct population segments (DPS), removed the current
species-level listing, and in its place listed four DPSs as endangered
and one DPS as threatened (81 FR 62259; September 8, 2016). The
remaining nine DPSs were not listed. The West Indies DPS, which is not
listed under the ESA, is the only DPS of humpback whale that is
expected to occur in the Project Area. The best estimate of population
abundance for the West Indies DPS is 12,312 individuals, as described
in the NMFS Status Review of the Humpback Whale under the Endangered
Species Act (Bettridge et al., 2015).
In New England waters, feeding is the principal activity of
humpback whales, and their distribution in this region has been largely
correlated to abundance of prey species, although behavior and
bathymetry are factors influencing foraging strategy (Payne et al.
1986, 1990). Humpback whales are frequently piscivorous when in New
England waters, feeding on herring (Clupea harengus), sand lance
(Ammodytes spp.), and other small fishes, as well as euphausiids in the
northern Gulf of Maine (Paquet et al. 1997). During winter, the
majority of humpback whales from North Atlantic feeding areas
(including the Gulf of Maine) mate and calve in the West Indies, where
spatial and genetic mixing among feeding groups occurs, though
significant numbers of animals are found in mid- and high-latitude
regions at this time and some individuals have
[[Page 7957]]
been sighted repeatedly within the same winter season, indicating that
not all humpback whales migrate south every winter (Waring et al.,
2017). Other sightings of note include 46 sightings of humpbacks in the
New York-New Jersey Harbor Estuary documented between 2011 and 2016
(Brown et al. 2017). Multiple humpbacks were observed feeding off Long
Island during July of 2016 (https://www.greateratlantic.fisheries.noaa.gov/mediacenter/2016/july/26_humpback_whales_visit_new_york.html, accessed 31 December, 2018) and
there were sightings during November-December 2016 near New York City
(https://www.greateratlantic.fisheries.noaa.gov/mediacenter/2016/december/09_humans_and_humpbacks_of_new_york_2.html, accessed 31
December 2018).
Kraus et al. (2016) observed humpback whales in the RI/MA & MA WEAs
and surrounding areas during all seasons. Humpback whales were observed
most often during spring and summer months, with a peak from April to
June. Calves were observed 10 times and feeding was observed 10 times
during the Kraus et al. (2016) study. That study also observed one
instance of courtship behavior. Although humpback whales were rarely
seen during fall and winter surveys, acoustic data indicate that this
species may be present within the MA WEA year-round, with the highest
rates of acoustic detections in winter and spring (Kraus et al. 2016).
Since January 2016, elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine through Florida. The event
has been declared a UME. Partial or full necropsy examinations have
been conducted on approximately half of the 111 known cases. A portion
of the whales have shown evidence of pre-mortem vessel strike; however,
this finding is not consistent across all of the whales examined so
more research is needed. NOAA is consulting with researchers that are
conducting studies on the humpback whale populations, and these efforts
may provide information on changes in whale distribution and habitat
use that could provide additional insight into how these vessel
interactions occurred. More detailed information is available at:
https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2019-humpback-whale-unusual-mortality-event-along-atlantic-coast (accessed
January 9, 2020). Three previous UMEs involving humpback whales have
occurred since 2000, in 2003, 2005, and 2006. A BIA for humpback whales
for feeding has been designated northeast of the lease areas from March
through December (LaBrecque et al. 2015).
Fin Whale
Fin whales are common in waters of the U.S. Atlantic Exclusive
Economic Zone (EEZ), principally from Cape Hatteras northward (Waring
et al., 2017). Fin whales are present north of 35-degree latitude in
every season and are broadly distributed throughout the western North
Atlantic for most of the year, though densities vary seasonally (Waring
et al., 2017). While fin whales typically feed in the Gulf of Maine and
the waters surrounding New England, their mating and calving (and
general wintering) areas are largely unknown (Hain et al. 1992, Hayes
et al. 2018). Acoustic detections of fin whale singers augment and
confirm these visual sighting conclusions for males. Recordings from
Massachusetts Bay, New York bight, and deep-ocean areas have detected
some level of fin whale singing from September through June (Watkins et
al. 1987, Clark and Gagnon 2002, Morano et al. 2012). These acoustic
observations from both coastal and deep-ocean regions support the
conclusion that male fin whales are broadly distributed throughout the
western North Atlantic for most of the year (Hayes et al. 2019).
Kraus et al. (2016) suggest that, compared to other baleen whale
species, fin whales have a high multi-seasonal relative abundance in
the Rhode Island/Massachusetts and Massachusetts Wind Energy Areas (RI/
MA & MA WEAs) and surrounding areas. Fin whales were observed in the
Massachusetts Wind Energy Area (MA WEA) in spring and summer. This
species was observed primarily in the offshore (southern) regions of
the RI/MA & MA WEAs during spring and was found closer to shore
(northern areas) during the summer months (Kraus et al. 2016). Calves
were observed three times and feeding was observed nine times during
the Kraus et al. (2016) study. Although fin whales were largely absent
from visual surveys in the RI/MA & MA WEAs in the fall and winter
months (Kraus et al. 2016), acoustic data indicated that this species
was present in the RI/MA & MA WEAs during all months of the year.
The main threats to fin whales are fishery interactions and vessel
collisions (Waring et al., 2017). New England waters represent a major
feeding ground for fin whales. The proposed Project Area would overlap
spatially and temporally with a feeding BIA for fin whales. The lease
areas are flanked by two Biologically Important Areas (BIAs) for
feeding fin whales-the area to the northeast is considered a BIA year-
round, while the area off the tip of Long Island to the southwest is a
BIA from March to October (LaBrecque et al. 2015).
Sei Whale
The Nova Scotia stock of sei whales can be found in deeper waters
of the continental shelf edge waters of the northeastern United States
and northeastward to south of Newfoundland. NOAA Fisheries considers
sei whales occurring from the U.S. East Coast to Cape Breton, Nova
Scotia, and east to 42[deg] W as the Nova Scotia stock of sei whales
(Waring et al. 2016; Hayes et al. 2018). In the Northwest Atlantic, it
is speculated that the whales migrate from south of Cape Cod along the
eastern Canadian coast in June and July, and return on a southward
migration again in September and October (Waring et al. 2014; 2017).
Spring is the period of greatest abundance in U.S. waters, with
sightings concentrated along the eastern margin of Georges Bank and
into the Northeast Channel area, and along the southwestern edge of
Georges Bank in the area of Hydrographer Canyon (Waring et al., 2015).
A BIA for feeding for sei whales occurs east of the lease areas from
May through November (LaBrecque et al. 2015).
Minke Whale
Minke whales can be found in temperate, tropical, and high-latitude
waters. The Canadian East Coast stock can be found in the area from the
western half of the Davis Strait (45 [deg]W) to the Gulf of Mexico
(Waring et al., 2017). This species generally occupies waters less than
100 m deep on the continental shelf. There appears to be a strong
seasonal component to minke whale distribution in which spring to fall
are times of relatively widespread and common occurrence, and when the
whales are most abundant in New England waters, while during winter the
species appears to be largely absent (Waring et al., 2017).
Kraus et al. (2016) observed minke whales in the RI/MA & MA WEAs
and surrounding areas primarily from May to June. This species
demonstrated a distinct seasonal habitat usage pattern that was
consistent throughout the study. Though minke whales were observed in
spring and summer months in the MA WEA, they were only observed in the
lease areas in the spring. Minke whales were not observed between
October and February, but acoustic data indicate the presence of this
species in the offshore proposed Project Area in winter months.
[[Page 7958]]
Since January 2017, elevated minke whale strandings have occurred
along the Atlantic coast from Maine through South Carolina, with
highest numbers in Massachusetts, Maine, and New York. Partial or full
necropsy examinations have been conducted on more than 60 percent of
the 79 known cases. Preliminary findings in several of the whales have
shown evidence of human interactions or infectious disease. These
findings are not consistent across all of the whales examined, so more
research is needed. More information is available at: https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2019-minke-whale-unusual-mortality-event-along-atlantic-coast (accessed January 9,
2020).
Sperm Whale
The distribution of the sperm whale in the U.S. EEZ occurs on the
continental shelf edge, over the continental slope, and into mid-ocean
regions (Waring et al. 2015). The basic social unit of the sperm whale
appears to be the mixed school of adult females plus their calves and
some juveniles of both sexes, normally numbering 20-40 animals in all.
Sperm whales are somewhat migratory; however, their migrations are not
as specific as seen in most of the baleen whale species. In the North
Atlantic, there appears to be a general shift northward during the
summer, but there is no clear migration in some temperate areas (Rice
1989). In summer, the distribution of sperm whales includes the area
east and north of Georges Bank and into the Northeast Channel region,
as well as the continental shelf (inshore of the 100-m isobath) south
of New England. In the fall, sperm whale occurrence south of New
England on the continental shelf is at its highest level, and there
remains a continental shelf edge occurrence in the mid-Atlantic bight.
In winter, sperm whales are concentrated east and northeast of Cape
Hatteras. Their distribution is typically associated with waters over
the continental shelf break and the continental slope and into deeper
waters (Whitehead et al. 1991). Sperm whale concentrations near drop-
offs and areas with strong currents and steep topography are correlated
with high productivity. These whales occur almost exclusively found at
the shelf break, regardless of season.
Kraus et al. (2016) observed sperm whales four times in the RI/MA &
MA WEAs during the summer and fall from 2011 to 2015. Sperm whales,
traveling singly or in groups of three or four, were observed three
times in August and September of 2012, and once in June of 2015. One
Long-Finned Pilot Whale
Long-finned pilot whales are found from North Carolina and north to
Iceland, Greenland and the Barents Sea (Waring et al., 2016). They are
generally found along the edge of the continental shelf (a depth of 330
to 3,300 feet (100 to 1,000 meters)), choosing areas of high relief or
submerged banks in cold or temperate shoreline waters. In the western
North Atlantic, long-finned pilot whales are pelagic, occurring in
especially high densities in winter and spring over the continental
slope, then moving inshore and onto the shelf in summer and autumn
following squid and mackerel populations (Reeves et al. 2002). They
frequently travel into the central and northern Georges Bank, Great
South Channel, and Gulf of Maine areas during the late spring and
remain through early fall (May and October) (Payne and Heinemann 1993).
Note that long-finned and short-finned pilot whales overlap
spatially along the mid-Atlantic shelf break between New Jersey and the
southern flank of Georges Bank (Payne and Heinemann 1993, Hayes et al.
2017) Long-finned pilot whales have occasionally been observed stranded
as far south as South Carolina, and short-finned pilot whale have
stranded as far north as Massachusetts (Hayes et al. 2017). The
latitudinal ranges of the two species therefore remain uncertain.
However, south of Cape Hatteras, most pilot whale sightings are
expected to be short-finned pilot whales, while north of approximately
42[deg] N, most pilot whale sightings are expected to be long-finned
pilot whales (Hayes et al. 2017). Based on the distributions described
in Hayes et al. (2017), pilot whale sightings in OCS-A 0501 and OCS-A
0522 would most likely be long-finned pilot whales.
Kraus et al. (2016) observed pilot whales infrequently in the RI/MA
& MA WEAs and surrounding areas. Effort-weighted average sighting rates
for pilot whales could not be calculated. No pilot whales were observed
during the fall or winter, and these species were only observed 11
times in the spring and three times in the summer.
Atlantic White-Sided Dolphin
White-sided dolphins are found in temperate and sub-polar waters of
the North Atlantic, primarily in continental shelf waters to the 100-m
depth contour from central West Greenland to North Carolina (Waring et
al., 2017). The Gulf of Maine stock is most common in continental shelf
waters from Hudson Canyon to Georges Bank, and in the Gulf of Maine and
lower Bay of Fundy. Sighting data indicate seasonal shifts in
distribution (Northridge et al., 1997). During January to May, low
numbers of white-sided dolphins are found from Georges Bank to Jeffreys
Ledge (off New Hampshire), with even lower numbers south of Georges
Bank, as documented by a few strandings collected on beaches of
Virginia to South Carolina. From June through September, large numbers
of white-sided dolphins are found from Georges Bank to the lower Bay of
Fundy. From October to December, white-sided dolphins occur at
intermediate densities from southern Georges Bank to southern Gulf of
Maine (Payne and Heinemann 1990). Sightings south of Georges Bank,
particularly around Hudson Canyon, occur year round but at low
densities.
Kraus et al. (2016) suggest that Atlantic white-sided dolphins
occur infrequently in the RI/MA & MA WEAs and surrounding areas.
Effort-weighted average sighting rates for Atlantic white-sided
dolphins could not be calculated, because this species was only
observed on eight occasions throughout the duration of the study
(October 2011 to June 2015). No Atlantic white-sided dolphins were
observed during the winter months, and this species was only sighted
twice in the fall and three times in the spring and summer
Common Dolphin
The short-beaked common dolphin is found world-wide in temperate to
subtropical seas. In the North Atlantic, short-beaked common dolphins
are commonly found over the continental shelf between the 100-m and
2,000-m isobaths and over prominent underwater topography and east to
the mid-Atlantic Ridge (Waring et al., 2016). This species is found
between Cape Hatteras and Georges Bank from mid-January to May,
although they migrate onto the northeast edge of Georges Bank in the
fall where large aggregations occur (Kenney and Vigness-Raposa 2009),
where large aggregations occur on Georges Bank in fall (Waring et al.
2007). Kraus et al. (2016) suggested that short-beaked common dolphins
occur year-round in the RI/MA & MA WEAs and surrounding areas. Short-
beaked common dolphins were the most frequently observed small cetacean
species within the Kraus et al. (2016) study area. Short-beaked common
dolphins were observed in the RI/MA & MA WEAs in all seasons and
observed in the Lease Area OCS-A 0501 in spring, summer, and fall. Only
the western North Atlantic stock may be present in the Project Area.
[[Page 7959]]
Bottlenose Dolphin
There are two distinct bottlenose dolphin ecotypes in the western
North Atlantic: the coastal and offshore forms (Waring et al., 2015).
The migratory coastal morphotype resides in waters typically less than
65.6 ft (20 m) deep, along the inner continental shelf (within 7.5 km
(4.6 miles) of shore), around islands, and is continuously distributed
south of Long Island, New York into the Gulf of Mexico. This migratory
coastal population is subdivided into 7 stocks based largely upon
spatial distribution (Waring et al. 2015). Of these 7 coastal stocks,
the Western North Atlantic migratory coastal stock is common in the
coastal continental shelf waters off the coast of New Jersey (Waring et
al. 2017). Generally, the offshore migratory morphotype is found
exclusively seaward of 34 km (21 miles) and in waters deeper than 34 m
(111.5 feet). This morphotype is most expected in waters north of Long
Island, New York (Waring et al. 2017; Hayes et al. 2017; 2018). During
HRG surveys, the Northern Migratory Coastal stock may be encountered
while surveying potential OECC routes in the nearshore. Bottlenose
dolphins encountered in the HRG Project Area would likely belong to the
Western North Atlantic Offshore stock (Hayes et al. 2018). It is
possible that a few animals could be from the Northern Migratory
Coastal stock, but they generally do not range farther north than New
Jersey.
Kraus et al. (2016) observed common bottlenose dolphins during all
seasons within the RI/MA & MA WEAs. Common bottlenose dolphins were the
second most commonly observed small cetacean species and exhibited
little seasonal variability in abundance. They were observed in the MA
WEA in all seasons and observed in Lease Area OCS-A 0501 in the fall
and winter
Risso's Dolphins
Risso's dolphins are distributed worldwide in tropical and
temperate seas (Jefferson et al. 2008, 2014), and in the Northwest
Atlantic occur from Florida to eastern Newfoundland (Leatherwood et al.
1976; Baird and Stacey 1991). Off the northeastern U.S. coast, Risso's
dolphins are distributed along the continental shelf edge from Cape
Hatteras northward to Georges Bank during spring, summer, and autumn
(CETAP 1982; Payne et al. 1984). In winter, the range is in the mid-
Atlantic Bight and extends outward into oceanic waters (Payne et al.
1984). Kraus et al. (2016) results suggest that Risso's dolphins occur
infrequently in the RI/MA & MA WEAs and surrounding areas.
Harbor Porpoise
In the Project Area, only the Gulf of Maine/Bay of Fundy stock may
be present. This stock is found in U.S. and Canadian Atlantic waters
and is concentrated in the northern Gulf of Maine and southern Bay of
Fundy region, generally in waters less than 150 m deep (Waring et al.,
2017). During fall (October-December) and spring (April-June) harbor
porpoises are widely dispersed from New Jersey to Maine. During winter
(January to March), intermediate densities of harbor porpoises can be
found in waters off New Jersey to North Carolina, and lower densities
are found in waters off New York to New Brunswick, Canada. They are
seen from the coastline to deep waters (>1800 m; Westgate et al. 1998),
although the majority of the population is found over the continental
shelf (Waring et al., 2017).
Kraus et al. (2016) indicate that harbor porpoises occur within the
RI/MA & MA WEAs in fall, winter, and spring. Harbor porpoises were
observed in groups ranging in size from three to 15 individuals and
were primarily observed in the Kraus et al. (2016) study area from
November through May, with very few sightings during June through
September
Harbor Seal
Harbor seals are year-round inhabitants of the coastal waters of
eastern Canada and Maine (Katona et al. 1993), and occur seasonally
along the coasts from southern New England to New Jersey from September
through late May. While harbor seals occur year-round north of Cape
Cod, they only occur during winter migration, typically September
through May, south of Cape Cod (Southern New England to New Jersey)
(Waring et al. 2015; Kenney and Vigness-Raposa 2009). Gray Seal
There are three major populations of gray seals found in the world;
eastern Canada (western North Atlantic stock), northwestern Europe and
the Baltic Sea. Gray seals in the Project Area belong to the western
North Atlantic stock. The range for this stock is thought to be from
New Jersey to Labrador. Current population trends show that gray seal
abundance is likely increasing in the U.S. Atlantic EEZ (Waring et al.,
2017). Although the rate of increase is unknown, surveys conducted
since their arrival in the 1980s indicate a steady increase in
abundance in both Maine and Massachusetts (Waring et al., 2017). It is
believed that recolonization by Canadian gray seals is the source of
the U.S. population (Waring et al., 2017). Gray seals are expected to
occur year-round in at least some potential OECC routes, with seasonal
occurrence in the offshore areas from September to May (Hayes et al.
2018).
Since July 2018, elevated numbers of harbor seal and gray seal
mortalities have occurred across Maine, New Hampshire and
Massachusetts. This event has been declared a UME. Additionally, seals
showing clinical signs of stranding have occurred as far south as
Virginia, although not in elevated numbers. Therefore the UME
investigation now encompasses all seal strandings from Maine to
Virginia. Between July 1, 2018 and January 9, 2020, a total of 3,050
seal strandings have been recorded as part of this designated Northeast
Pinniped UME. Based on tests conducted so far, the main pathogen found
in the seals is phocine distemper virus. Additional testing to identify
other factors that may be involved in this UME are underway.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65 dB
threshold from the normalized composite audiograms, with the exception
for lower limits for low-frequency cetaceans where the lower bound was
deemed to be biologically implausible and the lower bound from Southall
et al. (2007) retained. Marine mammal hearing groups and their
associated hearing ranges are provided in Table 3.
[[Page 7960]]
Table 3--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans 7 Hz to 35 kHz.
(baleen whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Kastelein et al., 2009; Reichmuth and Holt, 2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Fourteen mammal species (12 cetacean and 2 pinniped (both phocid)
species) have the reasonable potential to co-occur with the proposed
survey activities. Of the cetacean species that may be present, six are
classified as low-frequency cetaceans (i.e., all mysticete species),
five are classified as mid-frequency cetaceans (i.e., all delphinid
species and the sperm whale), and one is classified as high-frequency
cetacean (i.e., harbor porpoise).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take section, and the Proposed Mitigation section, to draw
conclusions regarding the likely impacts of these activities on the
reproductive success or survivorship of individuals and how those
impacts on individuals are likely to impact marine mammal species or
stocks.
Description of Sound Sources
This section contains a brief technical background on sound, on the
characteristics of certain sound types, and on metrics used in this
proposal inasmuch as the information is relevant to the specified
activity and to a discussion of the potential effects of the specified
activity on marine mammals found later in this document. For general
information on sound and its interaction with the marine environment,
please see, e.g., Au and Hastings (2008); Richardson et al. (1995).
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in hertz (Hz) or cycles per second. Wavelength is the
distance between two peaks or corresponding points of a sound wave
(length of one cycle). Higher frequency sounds have shorter wavelengths
than lower frequency sounds, and typically attenuate (decrease) more
rapidly, except in certain cases in shallower water. Amplitude is the
height of the sound pressure wave or the ``loudness'' of a sound and is
typically described using the relative unit of the decibel (dB). A
sound pressure level (SPL) in dB is described as the ratio between a
measured pressure and a reference pressure (for underwater sound, this
is 1 microPascal ([mu]Pa)), and is a logarithmic unit that accounts for
large variations in amplitude; therefore, a relatively small change in
dB corresponds to large changes in sound pressure. The source level
(SL) represents the SPL referenced at a distance of 1 m from the source
(referenced to 1 [mu]Pa), while the received level is the SPL at the
listener's position (referenced to 1 [mu]Pa).
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Root mean square is calculated by squaring
all of the sound amplitudes, averaging the squares, and then taking the
square root of the average. Root mean square accounts for both positive
and negative values; squaring the pressures makes all values positive
so that they may be accounted for in the summation of pressure levels
(Hastings and Popper, 2005). This measurement is often used in the
context of discussing behavioral effects, in part because behavioral
effects, which often result from auditory cues, may be better expressed
through averaged units than by peak pressures.
Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s)
represents the total energy in a stated frequency band over a stated
time interval or event, and considers both intensity and duration of
exposure. The per-pulse SEL is calculated over the time window
containing the entire pulse (i.e., 100 percent of the acoustic energy).
SEL is a cumulative metric; it can be accumulated over a single pulse,
or calculated over periods containing multiple pulses. Cumulative SEL
represents the total energy accumulated by a receiver over a defined
time window or during an event. Peak sound pressure (also referred to
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous
sound pressure measurable in the water at a specified distance from the
source, and is represented in the same units as the rms sound pressure.
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in a
manner similar to ripples on the surface of a pond and may be either
directed in a beam or beams or may radiate in all directions
(omnidirectional sources). The compressions and decompressions
associated with sound waves are detected as changes in pressure by
aquatic life and man-made sound receptors such as hydrophones.
Even in the absence of sound from the specified activity, the
underwater environment is typically loud due to ambient sound, which is
defined as environmental background sound levels
[[Page 7961]]
lacking a single source or point (Richardson et al., 1995). The sound
level of a region is defined by the total acoustical energy being
generated by known and unknown sources. These sources may include
physical (e.g., wind and waves, earthquakes, ice, atmospheric sound),
biological (e.g., sounds produced by marine mammals, fish, and
invertebrates), and anthropogenic (e.g., vessels, dredging,
construction) sound. A number of sources contribute to ambient sound,
including wind and waves, which are a main source of naturally
occurring ambient sound for frequencies between 200 hertz (Hz) and 50
kilohertz (kHz) (Mitson, 1995). In general, ambient sound levels tend
to increase with increasing wind speed and wave height. Precipitation
can become an important component of total sound at frequencies above
500 Hz, and possibly down to 100 Hz during quiet times. Marine mammals
can contribute significantly to ambient sound levels, as can some fish
and snapping shrimp. The frequency band for biological contributions is
from approximately 12 Hz to over 100 kHz. Sources of ambient sound
related to human activity include transportation (surface vessels),
dredging and construction, oil and gas drilling and production,
geophysical surveys, sonar, and explosions. Vessel noise typically
dominates the total ambient sound for frequencies between 20 and 300
Hz. In general, the frequencies of anthropogenic sounds are below 1 kHz
and, if higher frequency sound levels are created, they attenuate
rapidly.
The sum of the various natural and anthropogenic sound sources that
comprise ambient sound at any given location and time depends not only
on the source levels (as determined by current weather conditions and
levels of biological and human activity) but also on the ability of
sound to propagate through the environment. In turn, sound propagation
is dependent on the spatially and temporally varying properties of the
water column and sea floor, and is frequency-dependent. As a result of
the dependence on a large number of varying factors, ambient sound
levels can be expected to vary widely over both coarse and fine spatial
and temporal scales. Sound levels at a given frequency and location can
vary by 10-20 decibels (dB) from day to day (Richardson et al., 1995).
The result is that, depending on the source type and its intensity,
sound from the specified activity may be a negligible addition to the
local environment or could form a distinctive signal that may affect
marine mammals.
Sounds are often considered to fall into one of two general types:
Pulsed and non-pulsed. The distinction between these two sound types is
important because they have differing potential to cause physical
effects, particularly with regard to hearing (e.g., Ward, 1997 in
Southall et al., 2007). Please see Southall et al. (2007) for an in-
depth discussion of these concepts. The distinction between these two
sound types is not always obvious, as certain signals share properties
of both pulsed and non-pulsed sounds. A signal near a source could be
categorized as a pulse, but due to propagation effects as it moves
farther from the source, the signal duration becomes longer (e.g.,
Greene and Richardson, 1988).
Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic
booms, impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur
either as isolated events or repeated in some succession. Pulsed sounds
are all characterized by a relatively rapid rise from ambient pressure
to a maximal pressure value followed by a rapid decay period that may
include a period of diminishing, oscillating maximal and minimal
pressures, and generally have an increased capacity to induce physical
injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband, or broadband, brief or
prolonged, and may be either continuous or intermittent (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems. The
duration of such sounds, as received at a distance, can be greatly
extended in a highly reverberant environment.
Potential Effects of Underwater Sound
For study-specific citations, please see that work. Anthropogenic
sounds cover a broad range of frequencies and sound levels and can have
a range of highly variable impacts on marine life, from none or minor
to potentially severe responses, depending on received levels, duration
of exposure, behavioral context, and various other factors. The
potential effects of underwater sound from active acoustic sources can
potentially result in one or more of the following: Temporary or
permanent hearing impairment, non-auditory physical or physiological
effects, behavioral disturbance, stress, and masking (Richardson et
al., 1995; Gordon et al., 2004; Nowacek et al., 2007; Southall et al.,
2007; G[ouml]tz et al., 2009). The degree of effect is intrinsically
related to the signal characteristics, received level, distance from
the source, and duration of the sound exposure. In general, sudden,
high level sounds can cause hearing loss, as can longer exposures to
lower level sounds. Temporary or permanent loss of hearing will occur
almost exclusively for noise within an animal's hearing range.
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur, in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First is the area within which the acoustic signal would be
audible (potentially perceived) to the animal but not strong enough to
elicit any overt behavioral or physiological response. The next zone
corresponds with the area where the signal is audible to the animal and
of sufficient intensity to elicit behavioral or physiological
responsiveness. Third is a zone within which, for signals of high
intensity, the received level is sufficient to potentially cause
discomfort or tissue damage to auditory or other systems. Overlaying
these zones to a certain extent is the area within which masking (i.e.,
when a sound interferes with or masks the ability of an animal to
detect a signal of interest that is above the absolute hearing
threshold) may occur; the masking zone may be highly variable in size.
We describe the more severe effects (i.e., certain non-auditory
physical or physiological effects) only briefly as we do not expect
that there is a reasonable likelihood that HRG surveys may result in
such effects (see below for further discussion). Potential effects from
impulsive sound sources can range in severity from effects such as
behavioral disturbance or tactile perception to physical discomfort,
slight injury of the internal organs and the auditory system, or
mortality (Yelverton et al., 1973). Non-auditory physiological effects
or injuries that theoretically might occur in marine mammals exposed to
high level underwater sound or as a secondary effect of extreme
behavioral reactions (e.g., change in dive profile as a result of an
avoidance reaction) caused by exposure to sound include neurological
effects, bubble formation, resonance effects, and other types of organ
or tissue damage (Cox et al., 2006; Southall
[[Page 7962]]
et al., 2007; Zimmer and Tyack, 2007; Tal et al., 2015). The activities
considered here do not involve the use of devices such as explosives or
mid-frequency tactical sonar that are associated with these types of
effects.
Threshold Shift--Note that, in the following discussion, we refer
in many cases to a review article concerning studies of noise-induced
hearing loss conducted from 1996-2015 (i.e., Finneran, 2015). Marine
mammals exposed to high-intensity sound, or to lower-intensity sound
for prolonged periods, can experience hearing threshold shift (TS),
which is the loss of hearing sensitivity at certain frequency ranges
(Finneran, 2015). TS can be permanent (PTS), in which case the loss of
hearing sensitivity is not fully recoverable, or temporary (TTS), in
which case the animal's hearing threshold would recover over time
(Southall et al., 2007). Repeated sound exposure that leads to TTS
could cause PTS. In severe cases of PTS, there can be total or partial
deafness, while in most cases the animal has an impaired ability to
hear sounds in specific frequency ranges (Kryter, 1985).
When PTS occurs, there is physical damage to the sound receptors in
the ear (i.e., tissue damage), whereas TTS represents primarily tissue
fatigue and is reversible (Southall et al., 2007). In addition, other
investigators have suggested that TTS is within the normal bounds of
physiological variability and tolerance and does not represent physical
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to
constitute auditory injury.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals, and there is no PTS data for cetaceans, but such
relationships are assumed to be similar to those in humans and other
terrestrial mammals. PTS typically occurs at exposure levels at least
several decibels above (a 40-dB threshold shift approximates PTS onset;
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB
threshold shift approximates TTS onset; e.g., Southall et al. 2007).
Based on data from terrestrial mammals, a precautionary assumption is
that the PTS thresholds for impulse sounds (such as impact pile driving
pulses as received close to the source) are at least 6 dB higher than
the TTS threshold on a peak-pressure basis and PTS cumulative sound
exposure level thresholds are 15 to 20 dB higher than TTS cumulative
sound exposure level thresholds (Southall et al., 2007). Given the
higher level of sound or longer exposure duration necessary to cause
PTS as compared with TTS, it is considerably less likely that PTS could
occur.
TTS is the mildest form of hearing impairment that can occur during
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing
threshold rises, and a sound must be at a higher level in order to be
heard. In terrestrial and marine mammals, TTS can last from minutes or
hours to days (in cases of strong TTS). In many cases, hearing
sensitivity recovers rapidly after exposure to the sound ends. Few data
on sound levels and durations necessary to elicit mild TTS have been
obtained for marine mammals.
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS, and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to
serious. For example, a marine mammal may be able to readily compensate
for a brief, relatively small amount of TTS in a non-critical frequency
range that occurs during a time where ambient noise is lower and there
are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis))
and three species of pinnipeds (northern elephant seal (Mirounga
angustirostris), harbor seal, and California sea lion (Zalophus
californianus)) exposed to a limited number of sound sources (i.e.,
mostly tones and octave-band noise) in laboratory settings (Finneran,
2015). TTS was not observed in trained spotted (Phoca largha) and
ringed (Pusa hispida) seals exposed to impulsive noise at levels
matching previous predictions of TTS onset (Reichmuth et al., 2016). In
general, harbor seals and harbor porpoises have a lower TTS onset than
other measured pinniped or cetacean species (Finneran, 2015).
Additionally, the existing marine mammal TTS data come from a limited
number of individuals within these species. There are no data available
on noise-induced hearing loss for mysticetes. For summaries of data on
TTS in marine mammals or for further discussion of TTS onset
thresholds, please see Southall et al. (2007), Finneran and Jenkins
(2012), Finneran (2015), and NMFS (2018).
Animals in the Project Area during the proposed survey are unlikely
to incur TTS due to the characteristics of the sound sources, which
include relatively low source levels and generally very short pulses
and duration of the sound. Even for high-frequency cetacean species
(e.g., harbor porpoises), which may have increased sensitivity to TTS
(Lucke et al., 2009; Kastelein et al., 2012b), individuals would have
to make a very close approach and also remain very close to vessels
operating these sources in order to receive multiple exposures at
relatively high levels, as would be necessary to cause TTS.
Intermittent exposures--as would occur due to the brief, transient
signals produced by these sources--require a higher cumulative SEL to
induce TTS than would continuous exposures of the same duration (i.e.,
intermittent exposure results in lower levels of TTS) (Mooney et al.,
2009a; Finneran et al., 2010). Moreover, most marine mammals would more
likely avoid a loud sound source rather than swim in such close
proximity as to result in TTS. Kremser et al. (2005) noted that the
probability of a cetacean swimming through the area of exposure when a
sub-bottom profiler emits a pulse is small--because if the animal was
in the area, it would have to pass the transducer at close range in
order to be subjected to sound levels that could cause TTS and would
likely exhibit avoidance behavior to the area near the transducer
rather than swim through at such a close range. Further, the restricted
beam shape of the majority of the geophysical survey equipment proposed
for use makes it unlikely that an animal would be exposed more than
briefly during the passage of the vessel.
Behavioral Effects--Behavioral disturbance may include a variety of
effects, including subtle changes in behavior (e.g., minor or brief
avoidance of an area or changes in vocalizations), more conspicuous
changes in similar behavioral activities, and more sustained and/or
potentially severe reactions, such as displacement from or abandonment
of high-quality habitat. Behavioral responses to sound are highly
variable and context-specific and any reactions depend on numerous
intrinsic and extrinsic factors (e.g., species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
time of day), as well as the interplay between factors (e.g.,
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007;
Weilgart, 2007; Archer et al., 2010). Behavioral
[[Page 7963]]
reactions can vary not only among individuals but also within an
individual, depending on previous experience with a sound source,
context, and numerous other factors (Ellison et al., 2012), and can
vary depending on characteristics associated with the sound source
(e.g., whether it is moving or stationary, number of sources, distance
from the source). Please see Appendices B-C of Southall et al. (2007)
for a review of studies involving marine mammal behavioral responses to
sound.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. It is important to note that
habituation is appropriately considered as a ``progressive reduction in
response to stimuli that are perceived as neither aversive nor
beneficial,'' rather than as, more generally, moderation in response to
human disturbance (Bejder et al., 2009). The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure. As noted, behavioral state may affect the type of response.
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.,
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with
captive marine mammals have showed pronounced behavioral reactions,
including avoidance of loud sound sources (Ridgway et al., 1997;
Finneran et al., 2003). Observed responses of wild marine mammals to
loud pulsed sound sources (typically airguns or acoustic harassment
devices) have been varied but often consist of avoidance behavior or
other behavioral changes suggesting discomfort (Morton and Symonds,
2002; see also Richardson et al., 1995; Nowacek et al., 2007). However,
many delphinids approach low-frequency airgun source vessels with no
apparent discomfort or obvious behavioral change (e.g., Barkaszi et
al., 2012), indicating the importance of frequency output in relation
to the species' hearing sensitivity.
Available studies show wide variation in response to underwater
sound; therefore, it is difficult to predict specifically how any given
sound in a particular instance might affect marine mammals perceiving
the signal. If a marine mammal does react briefly to an underwater
sound by changing its behavior or moving a small distance, the impacts
of the change are unlikely to be significant to the individual, let
alone the stock or population. However, if a sound source displaces
marine mammals from an important feeding or breeding area for a
prolonged period, impacts on individuals and populations could be
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC,
2005). However, there are broad categories of potential response, which
we describe in greater detail here, that include alteration of dive
behavior, alteration of foraging behavior, effects to breathing,
interference with or alteration of vocalization, avoidance, and flight.
Changes in dive behavior can vary widely and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et
al.; 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior
may reflect interruptions in biologically significant activities (e.g.,
foraging) or they may be of little biological significance. The impact
of an alteration to dive behavior resulting from an acoustic exposure
depends on what the animal is doing at the time of the exposure and the
type and magnitude of the response.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Variations in respiration naturally vary with different behaviors
and alterations to breathing rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Various studies have shown that respiration rates may
either be unaffected or could increase, depending on the species and
signal characteristics, again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et
al., 2007; Gailey et al., 2016).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007). In some cases, animals may cease sound
production during production of aversive signals (Bowles et al., 1994).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
are known to change direction--deflecting from customary migratory
paths--in order to avoid noise from airgun surveys (Malme et al.,
1984). Avoidance may be short-term, with animals returning to the area
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996;
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006).
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement,
[[Page 7964]]
rate of travel). Relatively little information on flight responses of
marine mammals to anthropogenic signals exist, although observations of
flight responses to the presence of predators have occurred (Connor and
Heithaus, 1996). The result of a flight response could range from
brief, temporary exertion and displacement from the area where the
signal provokes flight to, in extreme cases, marine mammal strandings
(Evans and England, 2001). However, it should be noted that response to
a perceived predator does not necessarily invoke flight (Ford and
Reeves, 2008), and whether individuals are solitary or in groups may
influence the response.
Behavioral disturbance can also impact marine mammals in more
subtle ways. Increased vigilance may result in costs related to
diversion of focus and attention (i.e., when a response consists of
increased vigilance, it may come at the cost of decreased attention to
other critical behaviors such as foraging or resting). These effects
have generally not been demonstrated for marine mammals, but studies
involving fish and terrestrial animals have shown that increased
vigilance may substantially reduce feeding rates (e.g., Beauchamp and
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In
addition, chronic disturbance can cause population declines through
reduction of fitness (e.g., decline in body condition) and subsequent
reduction in reproductive success, survival, or both (e.g., Harrington
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However,
Ridgway et al. (2006) reported that increased vigilance in bottlenose
dolphins exposed to sound over a five-day period did not cause any
sleep deprivation or stress effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than one day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive behavioral reactions and multi-day anthropogenic
activities. For example, just because an activity lasts for multiple
days does not necessarily mean that individual animals are either
exposed to activity-related stressors for multiple days or, further,
exposed in a manner resulting in sustained multi-day substantive
behavioral responses.
We expect that some marine mammals may exhibit behavioral responses
to the HRG survey activities in the form of avoidance of the area
during the activity, especially the naturally shy harbor porpoise,
while others such as delphinids might be attracted to the survey
activities out of curiosity. However, because the HRG survey equipment
operates from a moving vessel, and the maximum radius to the Level B
harassment threshold is relatively small, the area and time that this
equipment would be affecting a given location is very small. Further,
once an area has been surveyed, it is not likely that it will be
surveyed again, thereby reducing the likelihood of repeated impacts
within the Project Area.
We have also considered the potential for severe behavioral
responses such as stranding and associated indirect injury or mortality
from Vineyard Wind's use of HRG survey equipment. Previous commenters
have referenced a 2008 mass stranding of approximately 100 melon-headed
whales in a Madagascar lagoon system. An investigation of the event
indicated that use of a high-frequency mapping system (12-kHz multibeam
echosounder) was the most plausible and likely initial behavioral
trigger of the event, while providing the caveat that there is no
unequivocal and easily identifiable single cause (Southall et al.,
2013). The investigatory panel's conclusion was based on (1) very close
temporal and spatial association and directed movement of the survey
with the stranding event; (2) the unusual nature of such an event
coupled with previously documented apparent behavioral sensitivity of
the species to other sound types (Southall et al., 2006; Brownell et
al., 2009); and (3) the fact that all other possible factors considered
were determined to be unlikely causes. Specifically, regarding survey
patterns prior to the event and in relation to bathymetry, the vessel
transited in a north-south direction on the shelf break parallel to the
shore, ensonifying large areas of deep-water habitat prior to operating
intermittently in a concentrated area offshore from the stranding site;
this may have trapped the animals between the sound source and the
shore, thus driving them towards the lagoon system. The investigatory
panel systematically excluded or deemed highly unlikely nearly all
potential reasons for these animals leaving their typical pelagic
habitat for an area extremely atypical for the species (i.e., a shallow
lagoon system). Notably, this was the first time that such a system has
been associated with a stranding event. The panel also noted several
site- and situation-specific secondary factors that may have
contributed to the avoidance responses that led to the eventual
entrapment and mortality of the whales. Specifically, shoreward-
directed surface currents and elevated chlorophyll levels in the area
preceding the event may have played a role (Southall et al., 2013). The
report also notes that prior use of a similar system in the general
area may have sensitized the animals and also concluded that, for
odontocete cetaceans that hear well in higher frequency ranges where
ambient noise is typically quite low, high-power active sonars
operating in this range may be more easily audible and have potential
effects over larger areas than low frequency systems that have more
typically been considered in terms of anthropogenic noise impacts. It
is, however, important to note that the relatively lower output
frequency, higher output power, and complex nature of the system
implicated in this event, in context of the other factors noted here,
likely produced a fairly unusual set of circumstances that indicate
that such events would likely remain rare and are not necessarily
relevant to use of lower-power, higher-frequency systems more commonly
used for HRG survey applications. The risk of similar events recurring
is likely very low, given the extensive use of active acoustic systems
used for scientific and navigational purposes worldwide on a daily
basis and the lack of direct evidence of such responses previously
reported.
Stress Responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle, 1950;
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary
[[Page 7965]]
hormones. Stress-induced changes in the secretion of pituitary hormones
have been implicated in failed reproduction, altered metabolism,
reduced immune competence, and behavioral disturbance (e.g., Moberg,
1987; Blecha, 2000). Increases in the circulation of glucocorticoids
are also equated with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found
that noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003).
NMFS does not expect that the generally short-term, intermittent,
and transitory HRG activities would create conditions of long-term,
continuous noise and chronic acoustic exposure leading to long-term
physiological stress responses in marine mammals.
Auditory Masking--Sound can disrupt behavior through masking, or
interfering with, an animal's ability to detect, recognize, or
discriminate between acoustic signals of interest (e.g., those used for
intraspecific communication and social interactions, prey detection,
predator avoidance, navigation) (Richardson et al., 1995; Erbe et al.,
2016). Masking occurs when the receipt of a sound is interfered with by
another coincident sound at similar frequencies and at similar or
higher intensity, and may occur whether the sound is natural (e.g.,
snapping shrimp, wind, waves, precipitation) or anthropogenic (e.g.,
shipping, sonar, seismic exploration) in origin. The ability of a noise
source to mask biologically important sounds depends on the
characteristics of both the noise source and the signal of interest
(e.g., signal-to-noise ratio, temporal variability, direction), in
relation to each other and to an animal's hearing abilities (e.g.,
sensitivity, frequency range, critical ratios, frequency
discrimination, directional discrimination, age or TTS hearing loss),
and existing ambient noise and propagation conditions.
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is man-made, it may be considered harassment
if disrupting behavioral patterns. It is important to distinguish TTS
and PTS, which persist after the sound exposure, from masking, which
occurs during the sound exposure. Because masking (without resulting in
TS) is not associated with abnormal physiological function, it is not
considered a physiological effect, but rather a potential behavioral
effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009) and may result in energetic or other costs as
animals change their vocalization behavior (e.g., Miller et al., 2000;
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt
et al., 2009). Masking can be reduced in situations where the signal
and noise come from different directions (Richardson et al., 1995),
through amplitude modulation of the signal, or through other
compensatory behaviors (Houser and Moore, 2014). Masking can be tested
directly in captive species (e.g., Erbe, 2008), but in wild populations
it must be either modeled or inferred from evidence of masking
compensation. There are few studies addressing real-world masking
sounds likely to be experienced by marine mammals in the wild (e.g.,
Branstetter et al., 2013).
Masking affects both senders and receivers of acoustic signals and
can potentially have long-term chronic effects on marine mammals at the
population level as well as at the individual level. Low-frequency
ambient sound levels have increased by as much as 20 dB (more than
three times in terms of SPL) in the world's ocean from pre-industrial
periods, with most of the increase from distant commercial shipping
(Hildebrand, 2009). All anthropogenic sound sources, but especially
chronic and lower-frequency signals (e.g., from vessel traffic),
contribute to elevated ambient sound levels, thus intensifying masking.
Marine mammal communications would not likely be masked appreciably
by the HRG equipment given the directionality of the signals (for most
geophysical survey equipment types proposed for use (Table 1) and the
brief period when an individual mammal is likely to be within its beam.
Vessel Strike
Vessel strikes of marine mammals can cause significant wounds,
which may lead to the death of the animal. An animal at the surface
could be struck directly by a vessel, a surfacing animal could hit the
bottom of a vessel, or a vessel's propeller could injure an animal just
below the surface. The severity of injuries typically depends on the
size and speed of the vessel (Knowlton and Kraus 2001; Laist et al.,
2001; Vanderlaan and Taggart 2007).
The most vulnerable marine mammals are those that spend extended
periods of time at the surface in order to restore oxygen levels within
their tissues after deep dives (e.g., the sperm whale). In addition,
some baleen whales, such as the North Atlantic right whale, seem
generally unresponsive to vessel sound, making them more susceptible to
vessel collisions (Nowacek et al., 2004). These species are primarily
large, slow moving whales. Smaller marine mammals (e.g., bottlenose
dolphin) move quickly through the water column and are often seen
riding the bow wave of large ships. Marine mammal responses to vessels
may include avoidance and changes in dive pattern (NRC 2003).
[[Page 7966]]
An examination of all known ship strikes from all shipping sources
(civilian and military) indicates vessel speed is a principal factor in
whether a vessel strike results in death (Knowlton and Kraus 2001;
Laist et al., 2001; Jensen and Silber 2003; Vanderlaan and Taggart
2007). In assessing records with known vessel speeds, Laist et al.
(2001) found a direct relationship between the occurrence of a whale
strike and the speed of the vessel involved in the collision. The
authors concluded that most deaths occurred when a vessel was traveling
in excess of 24.1 km/h (14.9 mph; 13 kn). Given the slow vessel speeds
and predictable course necessary for data acquisition, ship strike is
unlikely to occur during the geophysical surveys. Marine mammals would
be able to easily avoid the survey vessel due to the slow vessel speed.
Further, Vineyard Winds would implement measures (e.g., protected
species monitoring, vessel speed restrictions and separation distances;
see Proposed Mitigation) set forth in the BOEM lease to reduce the risk
of a vessel strike to marine mammal species in the Project Area.
Anticipated Effects on Marine Mammal Habitat
The proposed activities would not result in permanent impacts to
habitats used directly by marine mammals, but may have potential minor
and short-term impacts to food sources such as forage fish. The
proposed activities could affect acoustic habitat (see masking
discussion above), but meaningful impacts are unlikely. There are no
feeding areas, rookeries, or mating grounds known to be biologically
important to marine mammals within the proposed project area with the
exception of feeding BIAs for right, humpback, fin, and sei whales and
a migratory BIA for right whales which were described previously. There
is also designated critical habitat for right whales. The HRG survey
equipment will not contact the substrate and does not represent a
source of pollution. Impacts to substrate or from pollution are
therefore not discussed further.
Effects to Prey--Sound may affect marine mammals through impacts on
the abundance, behavior, or distribution of prey species (e.g.,
crustaceans, cephalopods, fish, zooplankton). Marine mammal prey varies
by species, season, and location and, for some, is not well documented.
Here, we describe studies regarding the effects of noise on known
marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Several studies
have demonstrated that impulse sounds might affect the distribution and
behavior of some fishes, potentially impacting foraging opportunities
or increasing energetic costs (e.g., Fewtrell and McCauley, 2012;
Pearson et al., 1992; Skalski et al., 1992; Santulli et al., 1999;
Paxton et al., 2017). However, some studies have shown no or slight
reaction to impulse sounds (e.g., Pena et al., 2013; Wardle et al.,
2001; Jorgenson and Gyselman, 2009; Cott et al., 2012). More commonly,
though, the impacts of noise on fish are temporary.
We are not aware of any available literature on impacts to marine
mammal prey from sound produced by HRG survey equipment. However, as
the HRG survey equipment introduces noise to the marine environment,
there is the potential for it to result in avoidance of the area around
the HRG survey activities on the part of marine mammal prey. The
duration of fish avoidance of an area after HRG surveys depart the area
is unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated. In general, impacts to marine mammal prey
species are expected to be minor and temporary due to the expected
short daily duration of the proposed HRG survey, the fact that the
proposed survey is mobile rather than stationary, and the relatively
small areas potentially affected. The areas likely impacted by the
proposed activities are relatively small compared to the available
habitat in the Atlantic Ocean. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large areas of fish and
marine mammal foraging habitat in the nearby vicinity. Based on the
information discussed herein, we conclude that impacts of the specified
activity are not likely to have more than short-term adverse effects on
any prey habitat or populations of prey species. Because of the
temporary nature of the disturbance, and the availability of similar
habitat and resources (e.g., prey species) in the surrounding area, any
impacts to marine mammal habitat are not expected to result in
significant or long-term consequences for individual marine mammals, or
to contribute to adverse impacts on their populations. Effects to
habitat will not be discussed further in this document.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization 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 be by Level B harassment only in the form of
disruption of behavioral patterns for individual marine mammals
resulting from exposure to HRG sources. Based on the nature of the
activity and the anticipated effectiveness of the mitigation measures
(i.e., exclusion zones and shutdown measures), discussed in detail
below in Proposed Mitigation section, Level A harassment is neither
anticipated nor proposed to be authorized.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds
[[Page 7967]]
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). Below, we describe the factors
considered here in more detail and present the proposed 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 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 (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 160 dB re 1 [mu]Pa (rms) for impulsive and/or
intermittent sources (e.g., impact pile driving) and 120 dB rms for
continuous sources (e.g., vibratory driving). Vineyard Wind's proposed
activity includes the use of impulsive sources (geophysical survey
equipment), and therefore use of the 160 dB re 1 [mu]Pa (rms) threshold
is 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 (cumulative sound exposure level (SELcum) and peak sound
pressure level metrics) 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 components of Vineyard Wind's
proposed activity includes the use of impulsive sources.
Predicted distances to Level A harassment isopleths, which vary
based on marine mammal functional hearing groups were calculated. The
updated acoustic thresholds for impulsive sounds (such as HRG survey
equipment) contained in the Technical Guidance (NMFS, 2018) were
presented as dual metric acoustic thresholds using both using both
SELcum and peak sound pressure level metrics. As dual
metrics, NMFS considers onset of PTS (Level A harassment) to have
occurred when either one of the two metrics is exceeded (i.e., metric
resulting in the largest isopleth). The SELcum metric
considers both level and duration of exposure, as well as auditory
weighting functions by marine mammal hearing group.
These thresholds are provided in Table 4 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 4--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.
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 proposed survey would entail the use of HRG equipment. The
distance to the isopleths corresponding to both Level A and Level B
harassment was calculated for all HRG equipment with the potential to
result in harassment of marine mammals. In their application, Vineyard
Wind employed a new model for determining the horizontal distance to
Level A harassment isopleths (See Appendix A). This new model was
developed by the applicant since the optional User Spreadsheet devised
by NMFS to calculate PTS isopleths is not
[[Page 7968]]
specifically designed for HRG surveys and does not take into account
seawater absorption or fully consider beam patterns, both of which can
influence received sound levels. To account for seawater absorption the
model calculated an appropriate absorption coefficient using the lowest
frequency employed by a specific device. To account for beam pattern,
an out-of-beam source correction factor was derived and used to
establish the out-of-beam source level as shown in Table 5. Separate
impact ranges were calculated using the in-beam source level at the
angle corresponding to the -3 dB half-width and the out-of-beam source
level in the horizontal direction. The higher of the two sound levels
was then selected for assessing impact distance. Dual metric acoustic
thresholds using both cumulative sound exposure level (SELcum) and peak
sound pressure level metrics were calculated. For all equipment
categories, use of the SELcum resulted in larger Level A harassment
isopleths.
As part of this model, sources that operate with a repetition rate
greater than 10 Hz were assessed with the non-impulsive source criteria
while sources with a repetition rate equal to or less than 10 Hz were
assessed with the impulsive source criteria. Under this system all HRG
sources would be classified as impulsive. NMFS does not agree with the
classification of all HRG sources as impulsive. The use of the 10 Hz
repetition rate would be precedent-setting and NMFS believes that this
issue requires further evaluation. However, NMFS opted to include the
modeled Level A distances in the proposed IHA, since classification of
all HRG sources as impulsive results in more conservative Level A
harassment isopleths.
NMFS considers the data provided by Crocker and Fratantonio (2016)
to represent the best available information on source levels associated
with HRG equipment and therefore recommends that source levels provided
by Crocker and Fratantonio (2016) be incorporated in the method
described above to estimate isopleth distances to the Level B
harassment threshold. In cases when the source level for a specific
type of HRG equipment is not provided in Crocker and Fratantonio
(2016), NMFS recommends that either the source levels provided by the
manufacturer be used, or, in instances where source levels provided by
the manufacturer are unavailable or unreliable, a proxy from Crocker
and Fratantonio (2016) be used instead. Table 1 shows the HRG equipment
types that may be used during the proposed surveys and the sound levels
associated with those HRG equipment types. Table A-3 in Appendix A of
the IHA application shows the literature sources for the sound source
levels that were incorporated into the model.
Table 5--Derived Out-of-Beam Source Levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
Description In-beam Out-of-beam
--------------------------------------------------------------------------------------------------------- -------------------------------
Source level Peak source Correction Source level Peak source
Equipment type System (dB re 1 level (dB re (dB) (dB re 1 level (dB re
[mu]Pa m) 1 [mu]Pa m) [mu]Pa m) 1 [mu]Pa m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shallow subbottom profilers............... EdgeTech Chirp 216.......... 178 182 -8.1 169.9 173.9
Shallow subbottom profilers............... Innomar SES 2000 Medium..... 241 247 -36.3 204.7 210.7
Deep seismic profilers.................... Applied Acoustics AA251 205 212 0.0 205 212
Boomer.
Deep seismic profilers.................... GeoMarine Geo Spark 2000 206 214 0.0 206 214
(400 tip).
Underwater positioning (USBL)............. SonarDyne Scout Pro......... 188 191 0.0 188 191
Underwater positioning (USBL)............. ixBlue Gaps................. 191 194 0.0 191 194
--------------------------------------------------------------------------------------------------------------------------------------------------------
NMFS has developed an interim methodology for determining the rms
sound pressure level (SPLrms) at the 160-dB isopleth for the purposes
of estimating take by Level B harassment resulting from exposure to HRG
survey equipment (NOAA 19 Sep 2019). Vineyard Wind used this
methodology with additional modifications that provide a more accurate
seawater absorption formula and account for energy emitted outside of
the primary beam of the source. This approach is described in detail in
Appendix B.
Note that Vineyard Wind initially proposed to use a blanket 100-ms
integration time to adjust the source level for all HRG sound sources
and all species to estimate Level B harassment distances. However, it
is known that integration time varies and depends on a multitude of
factors, including frequency, repetition rate, bandwidth, and species.
NMFS agrees that integration time is an important factor for
consideration, but using a single number to encompass all sound sources
and species seems like a potential oversimplification. Therefore, NMFS
used pulse duration only to estimate Level B harassment isopleths.
Calculated results using both pulse duration and a 100-ms integration
time are shown in Appendix B for comparative purposes.
Results of modeling described above indicated that sound produced
by the GeoMarine Geo Spark 2000 would propagate furthest to the Level B
harassment threshold; therefore, for the purposes of the exposure
analysis, it was assumed the GeoMarine Geo Spark 2000 would be active
during the entirety of the survey. The distance to the isopleth
corresponding to the threshold for Level B harassment for the GeoMarine
Geo Spark 2000 (estimated at 195 m; Table 6) was used as the basis of
the take calculation for all marine mammals. Note that this likely
provides a conservative estimate of the total ensonified area resulting
from the proposed activities. Vineyard Wind may not operate the
GeoMarine Geo Spark 2000 during the entirety of the proposed survey,
and for any survey segments in which it is not used the distance to the
Level B harassment threshold would be less than 195 m and the
corresponding ensonified area would also decrease. The model also
assumed that the sparker (GeoMarine Geo Spark 2000) is omnidirectional.
This assumption, which is made because the beam pattern is unknown,
results in precautionary estimates of received levels generally, and in
particular is likely to overestimate both SPL and PK. This
overestimation of the SPL likely results in an overestimation of the
number of takes by Level B harassment for this type of equipment.
[[Page 7969]]
Table 6--Modeled Radial Distances from HRG Survey Equipment to Isopleths Corresponding to Level A Harassment and Level B Harassment Thresholds \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
HRG survey equipment Level A harassment horizontal impact distance (m) Level B
----------------------------------------------------------------------------------------------------------------------------------------- harassment
horizontal
impact
Low frequency Mid frequency High frequency Phocid distance (m)
cetaceans cetaceans cetaceans pinnipeds ---------------
All
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shallow subbottom profilers............... EdgeTech Chirp 216.......... <1 <1 <1 <1 4
Shallow subbottom profilers............... Innomar SES 2000 Medium..... <1 <1 60 <1 116
Deep seismic profilers.................... Applied Acoustics AA251 <1 <1 60 <1 178
Boomer.
Deep seismic profilers.................... GeoMarine Geo Spark 2000 <1 <1 6 <1 195
(400 tip).
Underwater positioning (USBL)............. SonarDyne Scout Pro......... * * * * 24
Underwater positioning (USBL)............. ixBlue Gaps................. <1 m <1 m 55 <1 m 35
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note that SELcum was greater than peak SPL in all instances.
Due to the small estimated distances to Level A harassment
thresholds for all marine mammal functional hearing groups (less than 1
m for all hearing groups including all equipment types and no more than
60 m for high frequency cetaceans including all equipment types), and
in consideration of the proposed mitigation measures (see the Proposed
Mitigation section for more detail), NMFS has determined that the
likelihood of take of marine mammals in the form of Level A harassment
occurring as a result of the proposed survey is so low as to be
discountable, and we therefore do not propose to authorize the take by
Level A harassment of any marine mammals.
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
The habitat-based density models produced by the Duke University
Marine Geospatial Ecology Laboratory (Roberts et al., 2016, 2017, 2018)
represent the best available information regarding marine mammal
densities in the proposed Project Area. The density data presented by
Roberts et al. (2016, 2017, 2018) incorporates aerial and shipboard
line-transect survey data from NMFS and other organizations and
incorporates data from 8 physiographic and 16 dynamic oceanographic and
biological covariates, and controls for the influence of sea state,
group size, availability bias, and perception bias on the probability
of making a sighting. These density models were originally developed
for all cetacean taxa in the U.S. Atlantic (Roberts et al., 2016). In
subsequent years, certain models have been updated on the basis of
additional data as well as certain methodological improvements.
Although these updated models (and a newly developed seal density
model) are not currently publicly available, our evaluation of the
changes leads to a conclusion that these represent the best scientific
evidence available. More information, including the model results and
supplementary information for each model, is available online at
seamap.env.duke.edu/models/Duke-EC-GOM-2015/. Marine mammal density
estimates in the project area (animals/km \2\) were obtained using
these model results (Roberts et al., 2016, 2017, 2018). The updated
models incorporate additional sighting data, including sightings from
the NOAA Atlantic Marine Assessment Program for Protected Species
(AMAPPS) surveys from 2010-2014 (NEFSC & SEFSC, 2011, 2012, 2014a,
2014b, 2015, 2016).
For purposes of the exposure analysis, density data from Roberts et
al. (2016, 2017, 2018) were mapped using a geographic information
system (GIS). The density coverages that included any portion of the
proposed project area were selected for all survey months. Monthly
density data for each species were then averaged over the year to come
up with a mean annual density value for each species. The mean annual
density values used to estimate take numbers are shown in Table 7
below.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
In order to estimate the number of marine mammals predicted to be
exposed to sound levels that would result in harassment, radial
distances to predicted isopleths corresponding to harassment thresholds
are calculated, as described above. Those distances are then used to
calculate the area(s) around the HRG survey equipment predicted to be
ensonified to sound levels that exceed harassment thresholds. The area
estimated to be ensonified to relevant thresholds in a single day is
then calculated, based on areas predicted to be ensonified around the
HRG survey equipment and the estimated trackline distance traveled per
day by the survey vessel. Vineyard Wind estimates that proposed survey
vessels will achieve a maximum daily track line distance of 100 km per
day during proposed HRG surveys. This distance accounts for the vessel
traveling at roughly 4 knots and accounts for non-active survey
periods. Based on the maximum estimated distance to the Level B
harassment threshold of 195 m (Table 6) and the maximum estimated daily
track line distance of 100 km, an area of 39.12 km\2\ would be
ensonified to the Level B harassment threshold per day during Vineyard
Wind's proposed HRG surveys. As described above, this is a conservative
estimate as it assumes the HRG sources that result in the greatest
isopleth distances to the Level B harassment threshold would be
operated at all times during the all 736 vessel days.
The number of marine mammals expected to be incidentally taken per
day is then calculated by estimating the number of each species
predicted to occur within the daily ensonified area (animals/km\2\) by
incorporating the estimated marine mammal densities as described above.
Estimated numbers of each species taken per day are then multiplied by
the total number of vessel days (i.e., 736). The product is then
rounded, to generate an estimate of the total number of instances of
harassment expected for each species over the duration of the survey. A
summary of this method is illustrated in the following formula:
Estimated Take = D x ZOI x # of days
Where:
D = average species density (per km\2\) and ZOI = maximum daily
ensonified area to relevant thresholds.
Using this method to calculate take, Vineyard wind estimated that
there would be takes of several species by Level A harassment including
Atlantic White-sided dolphin, bottlenose
[[Page 7970]]
dolphin, short-beaked common dolphin, harbor porpoise, gray seal, and
harbor seal in the absence of mitigation (see Table 10 in the IHA
application for the estimated number of Level A takes for all potential
HRG equipment types). However, as described above, due to the very
small estimated distances to Level A harassment thresholds (Table 6),
and in consideration of the proposed mitigation measures, the
likelihood of the proposed survey resulting in take in the form of
Level A harassment is considered so low as to be discountable;
therefore, we do not propose to authorize take of any marine mammals by
Level A harassment. Proposed take numbers by Level B harassment are
shown in Table 7.
Table 7--Total Numbers of Potential Incidental Take of Marine Mammals Proposed for Authorization and Proposed
Takes as a Percentage of Population
----------------------------------------------------------------------------------------------------------------
Estimated
Annual density Level B Proposed takes Percent
Species mean (km-2) harassment by Level B population \1\
takes harassment
----------------------------------------------------------------------------------------------------------------
Fin whale....................................... 0.0023 67.28 67 0.91
Humpback whale.................................. 0.0016 45.73 46 3.28
Minke whale..................................... 0.001 41.20 41 0.17
North Atlantic right whale...................... 0.001 30.32 10 7.41
Sei whale....................................... 0.000 3.23 3.23 0.05
Atlantic white sided dolphin.................... 0.0351 1,011.19 1,011 1.10
Bottlenose dolphin.............................. 0.0283 814.91 815 1.30
Pilot whales \2\................................ 0.0049 1,41.98 142 2.52
Risso's dolphin \3\............................. 0.000 5.74 30 <0.08
Common dolphin.................................. 0.071 2,035.87 2,036 1.18
Sperm whale..................................... 0.000 3.82 4 0.09
Harbor porpoise................................. 0.0363 1,044.87 1,045 1.09
Gray seal....................................... 0.1404 4,043.67 4,044 14.90
Harbor seal..................................... 0.1404 4,043.67 4,044 5.33
----------------------------------------------------------------------------------------------------------------
\1\ Calculations of percentage of stock taken are based on the best available abundance estimate as shown in
Table 2. In most cases the best available abundance estimate is provided by Roberts et al. (2016, 2017, 2018),
when available, to maintain consistency with density estimates derived from Roberts et al. (2016, 2017, 2018).
For North Atlantic right whales the best available abundance estimate is derived from the 2018 North Atlantic
Right Whale Consortium 2019 Annual Report Card (Pettis et al., 2020).
\2\ Long- and short-finned pilot whales are grouped together as a guild.
\3\ Mean group sizes for species derived from Kenney and Vigness-Raposa (2010).
\4\ Exclusion zone exceeds Level B isopleth; take adjusted to 10 given duration of survey.
Proposed 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 such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). 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 such
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.
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.
Proposed Mitigation Measures
NMFS proposes the following mitigation measures be implemented
during Vineyard Wind's proposed marine site characterization surveys.
Marine Mammal Exclusion Zones, Buffer Zone and Monitoring Zone
Marine mammal exclusion zones (EZ) would be established around the
HRG survey equipment and monitored by protected species observers (PSO)
during HRG surveys as follows:
A 500-m EZ would be required for North Atlantic right whales
A 100-m EZ would be required for all other marine mammals
(with the exception of certain small dolphin species specified below)
If a marine mammal is detected approaching or entering the EZs
during the proposed survey, the vessel operator would adhere to the
shutdown procedures described below. In addition to the EZs described
above, PSOs would visually monitor a 200-m Buffer Zone. During use of
acoustic sources with the potential to result in marine mammal
harassment (i.e., anytime the acoustic source is active, including
ramp-up), occurrences of marine mammals within the Buffer Zone (but
outside the EZs) would be communicated to the vessel operator to
prepare for potential shutdown of the acoustic source. The Buffer Zone
is not applicable when the EZ is greater than 100 meters. PSOs would
also be required to observe a 500-m Monitoring Zone and record the
presence of all marine mammals within this zone. In addition, any
marine mammals observed within 195 m of the active HRG equipment
operating at or
[[Page 7971]]
below 180 kHz would be documented by PSOs as taken by Level B
harassment. The zones described above would be based upon the radial
distance from the active equipment (rather than being based on distance
from the vessel itself).
Visual Monitoring
NMFS only requires a single PSO to be on duty during daylight hours
and 30 minutes prior to and during nighttime ramp-ups for HRG surveys.
Vineyard Wind has voluntarily proposed that a minimum of two (2) NMFS-
approved PSOs must be on duty and conducting visual observations on all
survey vessels at all times when HRG equipment is in use (i.e. daylight
and nighttime operations). PSOs must be on duty 30 minutes prior to and
during nighttime ramp-ups of HRG equipment. Visual monitoring would
begin no less than 30 minutes prior to ramp-up of HRG equipment and
would continue until 30 minutes after use of the acoustic source. PSOs
would establish and monitor the applicable EZs, Buffer Zone and
Monitoring Zone as described above. Visual PSOs would coordinate to
ensure 360[deg] visual coverage around the vessel from the most
appropriate observation posts, and would conduct visual observations
using binoculars and the naked eye while free from distractions and in
a consistent, systematic, and diligent manner. PSOs would estimate
distances to marine mammals located in proximity to the vessel and/or
relevant using range finders. It would be the responsibility of the
Lead PSO on duty to communicate the presence of marine mammals as well
as to communicate and enforce the action(s) that are necessary to
ensure mitigation and monitoring requirements are implemented as
appropriate. Position data would be recorded using hand-held or vessel
global positioning system (GPS) units for each confirmed marine mammal
sighting.
Pre-Clearance of the Exclusion Zones
Prior to initiating HRG survey activities, Vineyard Wind would
implement a 30-minute pre-clearance period. During pre-clearance
monitoring (i.e., before ramp-up of HRG equipment begins), the Buffer
Zone would also act as an extension of the 100-m EZ in that
observations of marine mammals within the 200-m Buffer Zone would also
preclude HRG operations from beginning. During this period, PSOs would
ensure that no marine mammals are observed within 200 m of the survey
equipment (500 m in the case of North Atlantic right whales). HRG
equipment would not start up until this 200-m zone (or, 500-m zone in
the case of North Atlantic right whales) is clear of marine mammals for
at least 30 minutes. The vessel operator would notify a designated PSO
of the proposed start of HRG survey equipment as agreed upon with the
lead PSO; the notification time should not be less than 30 minutes
prior to the planned initiation of HRG equipment order to allow the
PSOs time to monitor the EZs and Buffer Zone for the 30 minutes of pre-
clearance. A PSO conducting pre-clearance observations would be
notified again immediately prior to initiating active HRG sources.
If a marine mammal were observed within the relevant EZs or Buffer
Zone during the pre-clearance period, initiation of HRG survey
equipment would not begin until the animal(s) has been observed exiting
the respective EZ or Buffer Zone, or, until an additional time period
has elapsed with no further sighting (i.e., minimum 15 minutes for
small odontocetes and seals, and 30 minutes for all other species). The
pre-clearance requirement would include small delphinoids that approach
the vessel (e.g., bow ride). PSOs would also continue to monitor the
zone for 30 minutes after survey equipment is shut down or survey
activity has concluded.
Ramp-Up of Survey Equipment
When technically feasible, a ramp-up procedure would be used for
geophysical survey equipment capable of adjusting energy levels at the
start or re-start of survey activities. The ramp-up procedure would be
used at the beginning of HRG survey activities in order to provide
additional protection to marine mammals near the Project Area by
allowing them to detect the presence of the survey and vacate the area
prior to the commencement of survey equipment operation at full power.
Ramp-up of the survey equipment would not begin until the relevant EZs
and Buffer Zone has been cleared by the PSOs, as described above. HRG
equipment would be initiated at their lowest power output and would be
incrementally increased to full power. If any marine mammals are
detected within the EZs or Buffer Zone prior to or during ramp-up, the
HRG equipment would be shut down (as described below).
Shutdown Procedures
If an HRG source is active and a marine mammal is observed within
or entering a relevant EZ (as described above) an immediate shutdown of
the HRG survey equipment would be required. When shutdown is called for
by a PSO, the acoustic source would be immediately deactivated and any
dispute resolved only following deactivation. Any PSO on duty would
have the authority to delay the start of survey operations or to call
for shutdown of the acoustic source if a marine mammal is detected
within the applicable EZ. The vessel operator would establish and
maintain clear lines of communication directly between PSOs on duty and
crew controlling the HRG source(s) to ensure that shutdown commands are
conveyed swiftly while allowing PSOs to maintain watch. Subsequent
restart of the HRG equipment would only occur after the marine mammal
has either been observed exiting the relevant EZ, or, until an
additional time period has elapsed with no further sighting of the
animal within the relevant EZ (i.e., 15 minutes for small odontocetes
and seals, and 30 minutes for large whales).
Upon implementation of shutdown, the HRG source may be reactivated
after the marine mammal that triggered the shutdown has been observed
exiting the applicable EZ (i.e., the animal is not required to fully
exit the Buffer Zone where applicable) or, following a clearance period
of 15 minutes for small odontocetes and seals and 30 minutes for all
other species with no further observation of the marine mammal(s)
within the relevant EZ. If the HRG equipment shuts down for brief
periods (i.e., less than 30 minutes) for reasons other than mitigation
(e.g., mechanical or electronic failure) the equipment may be re-
activated as soon as is practicable at full operational level, without
30 minutes of pre-clearance, only if PSOs have maintained constant
visual observation during the shutdown and no visual detections of
marine mammals occurred within the applicable EZs and Buffer Zone
during that time. For a shutdown of 30 minutes or longer, or if visual
observation was not continued diligently during the pause, pre-
clearance observation is required, as described above.
The shutdown requirement would be waived for certain genera of
small delphinids (i.e., Delphinus, Lagenorhynchus, and Tursiops) under
certain circumstances. If a delphinid(s) from these genera is visually
detected approaching the vessel (i.e., to bow ride) or towed survey
equipment, shutdown would not be required. If there is uncertainty
regarding identification of a marine mammal species (i.e., whether the
observed marine mammal(s) belongs to one of the delphinid genera for
which shutdown is waived), PSOs would use best professional judgment in
making the decision to call for a shutdown.
If a species for which authorization has not been granted, or, a
species for
[[Page 7972]]
which authorization has been granted but the authorized number of takes
have been met, approaches or is observed within the area encompassing
the Level B harassment isopleth (195 m), shutdown would occur.
Vessel Strike Avoidance
Vessel strike avoidance measures would include, but would not be
limited to, the following, except under circumstances when complying
with these requirements would put the safety of the vessel or crew at
risk:
All vessel operators and crew will maintain vigilant watch
for cetaceans and pinnipeds, and slow down or stop their vessel to
avoid striking these protected species;
All survey vessels, regardless of size, must observe a 10-
knot speed restriction in specific areas designated by NMFS for the
protection of North Atlantic right whales from vessel strikes: Any DMAs
when in effect, and the Block Island Seasonal Management Area (SMA)
(from November 1 through April 30), Cape Cod Bay SMA (from January 1
through May 15), Off Race Point SMA (from March 1 through April 30) and
Great South Channel SMA (from April 1 through July 31). Note that this
requirement includes vessels, regardless of size, to adhere to a 10
knot speed limit in SMAs and DMAs, not just vessels 65 ft or greater in
length.
All vessel operators will reduce vessel speed to 10 knots
(18.5 km/hr) or less when any large whale, any mother/calf pairs, large
assemblages of non-delphinoid cetaceans are observed near (within 100 m
(330 ft)) an underway vessel;
All vessels will maintain a separation distance of 500 m
(1640 ft) or greater from any sighted North Atlantic right whale;
If underway, vessels must steer a course away from any
sighted North Atlantic right whale at 10 knots (18.5 km/hr) or less
until the 500-m (1640 ft) minimum separation distance has been
established. If a North Atlantic right whale is sighted in a vessel's
path, or within 100 m (330 ft) to an underway vessel, the underway
vessel must reduce speed and shift the engine to neutral. Engines will
not be engaged until the North Atlantic right whale has moved outside
of the vessel's path and beyond 100 m. If stationary, the vessel must
not engage engines until the North Atlantic right whale has moved
beyond 100 m;
All vessels will maintain a separation distance of 100 m
(330 ft) or greater from any sighted non-delphinoid cetacean. If
sighted, the vessel underway must reduce speed and shift the engine to
neutral, and must not engage the engines until the non-delphinoid
cetacean has moved outside of the vessel's path and beyond 100 m. If a
survey vessel is stationary, the vessel will not engage engines until
the non-delphinoid cetacean has moved out of the vessel's path and
beyond 100 m;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted delphinoid cetacean. Any vessel
underway remain parallel to a sighted delphinoid cetacean's course
whenever possible, and avoid excessive speed or abrupt changes in
direction. Any vessel underway reduces vessel speed to 10 knots (18.5
km/hr) or less when pods (including mother/calf pairs) or large
assemblages of delphinoid cetaceans are observed. Vessels may not
adjust course and speed until the delphinoid cetaceans have moved
beyond 50 m and/or the abeam of the underway vessel;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted pinniped; and
All vessels underway will not divert or alter course in
order to approach any whale, delphinoid cetacean, or pinniped. Any
vessel underway will avoid excessive speed or abrupt changes in
direction to avoid injury to the sighted cetacean or pinniped.
Project-specific training will be conducted for all vessel crew
prior to the start of survey activities. Confirmation of the training
and understanding of the requirements will be documented on a training
course log sheet. Signing the log sheet will certify that the crew
members understand and will comply with the necessary requirements
throughout the survey activities.
Seasonal Operating Requirements
Vineyard Wind will conduct HRG survey activities in the Cape Cod
Bay SMA and Off Race Point SMA only during the months of August and
September to ensure sufficient buffer between the SMA restrictions
(January to May 15) and known seasonal occurrence of the NARW north and
northeast of Cape Cod (fall, winter, and spring). Vineyard Wind will
also limit to three the number survey vessels that will operate
concurrently from March through June within the lease areas (OCS-A 0501
and 0487) and OECC areas north of the lease areas up to, but not
including, coastal and bay waters. The boundaries of this area are
delineated by a polygon with the following vertices: 40.746 N 70.748 W;
40.953 N 71.284 W; 41.188 N 71.284 W; ~41.348 N 70.835 W; 41.35 N
70.455 W; 41.097 N 70.372 W; and 41.021 N 70.37 W. This area is
delineated by the dashed line shown in Figure 2. Another seasonal
restriction area south of Nantucket will be in effect from December to
February in the area delineated by the current DMA (Effective from
January 31, 2020 through February 15, 2020). The winter seasonal
restriction area is delineated by latitudes and longitudes of 41.1838
N; 40.3666 N; 69.5333 W; and 70.6166 W. This area is delineated by the
solid line in Figure 2.
[[Page 7973]]
[GRAPHIC] [TIFF OMITTED] TN12FE20.002
Vineyard Wind would operate either a single vessel, two vessels
concurrently or, for short periods, no more than three survey vessels
concurrently in the areas described above during the December-February
and March-June timeframes when right whale densities are greatest. The
seasonal restrictions described above will help to reduce both the
number and intensity of right whale takes.
Vineyard Wind would also employ passive acoustic monitoring (PAM)
to support monitoring during night time operations to provide for
acquisition of species detections at night. While PAM is not typically
required by NMFS for HRG surveys, it may a provide additional benefit
as a mitigation and monitoring measure to further limit potential
exposure to underwater sound at levels that could result in injury or
behavioral harassment.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, NMFS has preliminarily
determined that the proposed 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.
Proposed 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).
Mitigation and monitoring effectiveness.
[[Page 7974]]
Proposed Monitoring Measures
As described above, visual monitoring would be performed by
qualified and NMFS-approved PSOs. Vineyard Wind would use independent,
dedicated, trained PSOs, meaning that the PSOs must be employed by a
third-party observer provider, must have no tasks other than to conduct
observational effort, collect data, and communicate with and instruct
relevant vessel crew with regard to the presence of marine mammals and
mitigation requirements (including brief alerts regarding maritime
hazards), and must have successfully completed an approved PSO training
course appropriate for their designated task. Vineyard Wind would
provide resumes of all proposed PSOs (including alternates) to NMFS for
review and approval prior to the start of survey operations.
During survey operations (e.g., any day on which use of an HRG
source is planned to occur), a minimum of two PSOs must be on duty and
conducting visual observations at all times on all active survey
vessels when HRG equipment is operating, including both daytime and
nighttime operations. Visual monitoring would begin no less than 30
minutes prior to initiation of HRG survey equipment and would continue
until one hour after use of the acoustic source ceases. PSOs would
coordinate to ensure 360[deg] visual coverage around the vessel from
the most appropriate observation posts, and would conduct visual
observations using binoculars and the naked eye while free from
distractions and in a consistent, systematic, and diligent manner. PSOs
may be on watch for a maximum of four consecutive hours followed by a
break of at least two hours between watches and may conduct a maximum
of 12 hours of observation per 24-hour period. In cases where multiple
vessels are surveying concurrently, any observations of marine mammals
would be communicated to PSOs on all survey vessels.
PSOs would be equipped with binoculars and have the ability to
estimate distances to marine mammals located in proximity to the vessel
and/or exclusion zone using range finders. Reticulated binoculars will
also be available to PSOs for use as appropriate based on conditions
and visibility to support the monitoring of marine mammals. Position
data would be recorded using hand-held or vessel GPS units for each
sighting. Observations would take place from the highest available
vantage point on the survey vessel. General 360-degree scanning would
occur during the monitoring periods, and target scanning by the PSO
would occur when alerted of a marine mammal presence.
During good conditions (e.g., daylight hours; Beaufort sea state
(BSS) 3 or less), to the maximum extent practicable, PSOs would conduct
observations when the acoustic source is not operating for comparison
of sighting rates and behavior with and without use of the acoustic
source and between acquisition periods. Any observations of marine
mammals by crew members aboard any vessel associated with the survey
would be relayed to the PSO team.
Data on all PSO observations would be recorded based on standard
PSO collection requirements. This would include dates, times, and
locations of survey operations; dates and times of observations,
location and weather; details of marine mammal sightings (e.g.,
species, numbers, behavior); and details of any observed marine mammal
take that occurs (e.g., noted behavioral disturbances).
Proposed Reporting Measures
Within 90 days after completion of survey activities, a final
technical report will be provided to NMFS that fully documents the
methods and monitoring protocols, summarizes the data recorded during
monitoring, summarizes the number of marine mammals estimated to have
been taken during survey activities (by species, when known),
summarizes the mitigation actions taken during surveys (including what
type of mitigation and the species and number of animals that prompted
the mitigation action, when known), and provides an interpretation of
the results and effectiveness of all mitigation and monitoring. Any
recommendations made by NMFS must be addressed in the final report
prior to acceptance by NMFS.
In the event that Vineyard Wind personnel discover an injured or
dead marine mammal, Vineyard Wind shall report the incident to the
Office of Protected Resources (OPR), NMFS and to the New England/Mid-
Atlantic Regional Stranding Coordinator as soon as feasible. 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.
In the event of a ship strike of a marine mammal by any vessel
involved in the activities covered by the authorization, the IHA-holder
shall report the incident to OPR, NMFS and to the New England/Mid-
Atlantic Regional Stranding Coordinator as soon as feasible. The report
must include the following information:
Time, date, and location (latitude/longitude) of the
incident;
Species identification (if known) or description of the
animal(s) involved;
Vessel's speed during and leading up to the incident;
Vessel's course/heading and what operations were being
conducted (if applicable);
Status of all sound sources in use;
Description of avoidance measures/requirements that were
in place at the time of the strike and what additional measures were
taken, if any, to avoid strike;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, visibility) immediately preceding the
strike;
Estimated size and length of animal that was struck;
Description of the behavior of the marine mammal
immediately preceding and following the strike;
If available, description of the presence and behavior of
any other marine mammals immediately preceding the strike;
Estimated fate of the animal (e.g., dead, injured but
alive, injured and moving, blood or tissue observed in the water,
status unknown, disappeared); and
To the extent practicable, photographs or video footage of
the animal(s).
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-
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''
[[Page 7975]]
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).
To avoid repetition, our analysis applies to all the species listed
in Table 2, given that NMFS expects the anticipated effects of the
proposed survey to be similar in nature. As discussed in the
``Potential Effects of the Specified Activity on Marine Mammals and
Their Habitat'' section, PTS, masking, non-auditory physical effects,
and vessel strike are not expected to occur.
The majority of impacts to marine mammals are expected to be short-
term disruption of behavioral patterns, primarily in the form of
avoidance or potential interruption of foraging. Marine mammal feeding
behavior is not likely to be significantly impacted.
Regarding impacts to marine mammal habitat, prey species are
mobile, and are broadly distributed throughout the Project Area and the
footprint of the activity is small; therefore, marine mammals that may
be temporarily displaced during survey activities are expected to be
able to resume foraging once they have moved away from areas with
disturbing levels of underwater noise. Because of the availability of
similar habitat and resources in the surrounding area the impacts to
marine mammals and the food sources that they utilize are not expected
to cause significant or long-term consequences for individual marine
mammals or their populations. The HRG survey equipment itself will not
result in physical habitat disturbance. Avoidance of the area around
the HRG survey activities by marine mammal prey species is possible.
However, any avoidance by prey species would be expected to be short
term and temporary.
ESA-listed species for which takes are authorized are right, fin,
sei, and sperm whales, and these effects are anticipated to be limited
to lower level behavioral effects. NMFS does not anticipate that
serious injury or mortality would occur to ESA-listed species, even in
the absence of mitigation and no serious injury or mortality is
authorized. As discussed in the Potential Effects section, non-auditory
physical effects and vessel strike are not expected to occur. We expect
that most potential takes would be in the form of short-term Level B
behavioral harassment in the form of temporary avoidance of the area or
decreased foraging (if such activity were occurring), reactions that
are considered to be of low severity and with no lasting biological
consequences (e.g., Southall et al., 2007). The proposed survey is not
anticipated to affect the fitness or reproductive success of individual
animals. Since impacts to individual survivorship and fecundity are
unlikely, the proposed survey is not expected to result in population-
level effects for any ESA-listed species or alter current population
trends of any ESA-listed species.
The status of the North Atlantic right whale population is of
heightened concern and, therefore, merits additional analysis. NMFS has
rigorously assessed potential impacts to right whales from this survey.
We have established a 500-m shutdown zone for right whales which is
precautionary considering the Level B harassment isopleth for the
largest source utilized (i.e. GeoMarine Geo Spark 2000 (400 tip) is
estimated to be 195 m.
NMFS is also requiring Vineyard Wind to limit the number of survey
vessels operating concurrently to no more than three in specified areas
during periods when right whale densities are likely to be elevated.
This includes a specified area approximately 31 miles due south of
Nantucket including Lease Area OCS-A 0522 from December to February as
well as Lease Area OCS-A 0501 and surrounding Project Areas south and
southwest of Martha's Vineyard from March to June. Numerous right whale
aggregations have been reported in these areas during the winter and
spring. Furthermore, surveys in right whale critical habitat area will
be limited to August and September when the whales are unlikely to be
present. Due to the length of the survey and continuous night
operations, it is conceivable that a limited number of right whales
could enter into the Level B harassment zone without being observed.
Any potential impacts to right whales would consist of, at most, low-
level, short-term behavioral harassment in a limited number of animals.
The proposed Project Area encompasses or is in close proximity to
feeding BIAs for right whales (February-April), humpback whales (March-
December), fin whales (March-October), and sei whales (May-November) as
well as a migratory BIA or right whales (March-April and November-
December. Most of these feeding BIAs are extensive and sufficiently
large (705 km\2\ and 3,149 km\2\ for right whales; 47,701 km\2\ for
humpback whales; 2,933 km\2\ for fin whales; and 56,609 km\2\ for sei
whales), and the acoustic footprint of the proposed survey is
sufficiently small that feeding opportunities for these whales would
not be reduced appreciably. Any whales temporarily displaced from the
proposed Project Area would be expected to have sufficient remaining
feeding habitat available to them, and would not be prevented from
feeding in other areas within the biologically important feeding
habitat. In addition, any displacement of whales from the BIA or
interruption of foraging bouts would be expected to be temporary in
nature. Therefore, we do not expect whales with feeding BIAs to be
negatively impacted by the proposed survey.
A migratory BIA for North Atlantic right whales (effective March-
April and November-December) extends from Massachusetts to Florida
(LaBrecque, et al., 2015). Off the south coast of Massachusetts and
Rhode Island, this BIA extends from the coast to beyond the shelf
break. The fact that the spatial acoustic footprint of the proposed
survey is very small relative to the spatial extent of the available
migratory habitat means that right whale migration is not expected to
be impacted by the proposed survey. Required vessel strike avoidance
measures will also decrease risk of ship strike during migration. NMFS
is expanding the standard avoidance measures by requiring that all
vessels, regardless of size, adhere to a 10 knot speed limit in SMAs
and DMA. Additionally, limited take by Level B harassment of North
Atlantic right whales has been authorized as HRG survey operations are
required to shut down at 500 m to minimize the potential for behavioral
harassment of this species.
As noted previously, elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine through Florida since
January 2016. Of the cases examined, approximately half had evidence of
human interaction (ship strike or entanglement). The UME does not yet
provide cause for concern regarding population-level impacts. Despite
the UME, the relevant population of
[[Page 7976]]
humpback whales (the West Indies breeding population, or distinct
population segment (DPS)) remains healthy. Beginning in January 2017,
elevated minke whale strandings have occurred along the Atlantic coast
from Maine through South Carolina, with highest numbers in
Massachusetts, Maine, and New York. This event does not provide cause
for concern regarding population level impacts, as the likely
population abundance is greater than 20,000 whales. Elevated North
Atlantic right whale mortalities began in June 2017, primarily in
Canada. Overall, preliminary findings support human interactions,
specifically vessel strikes or rope entanglements, as the cause of
death for the majority of the right whales. Elevated numbers of harbor
seal and gray seal mortalities were first observed in July, 2018 and
have occurred across Maine, New Hampshire and Massachusetts. Based on
tests conducted so far, the main pathogen found in the seals is phocine
distemper virus although additional testing to identify other factors
that may be involved in this UME are underway. The UME does not yet
provide cause for concern regarding population-level impacts to any of
these stocks. For harbor seals, the population abundance is over 75,000
and annual M/SI (345) is well below PBR (2,006) (Hayes et al., 2018).
For gray seals, the population abundance in the United States is over
27,000, with an estimated abundance including seals in Canada of
approximately 505,000, and abundance is likely increasing in the U.S.
Atlantic EEZ as well as in Canada (Hayes et al., 2018).
Direct physical interactions (ship strikes and entanglements)
appear to be responsible for many of the UME humpback and right whale
mortalities recorded. The proposed HRG survey will require ship strike
avoidance measures which would minimize the risk of ship strikes while
fishing gear and in-water lines will not be employed as part of the
survey. Furthermore, the proposed activities are not expected to
promote the transmission of infectious disease among marine mammals.
The survey is not expected to result in the deaths of any marine
mammals or combine with the effects of the ongoing UMEs to result in
any additional impacts not analyzed here. Accordingly, Vineyard Wind
did not request, and NMFS is not proposing to authorize, take of marine
mammals by serious injury, or mortality.
The required mitigation measures are expected to reduce the number
and/or severity of takes by giving animals the opportunity to move away
from the sound source before HRG survey equipment reaches full energy
and preventing animals from being exposed to sound levels that have the
potential to cause injury (Level A harassment) and more severe Level B
harassment during HRG survey activities, even in the biologically
important areas described above. No Level A harassment is anticipated
or authorized.
NMFS expects that most takes would primarily be in the form of
short-term Level B behavioral harassment in the form of brief startling
reaction and/or temporary vacating of the area, or decreased foraging
(if such activity were occurring)--reactions that (at the scale and
intensity anticipated here) are considered to be of low severity and
with no lasting biological consequences. Since both the source and the
marine mammals are mobile, only a smaller area would be ensonified by
sound levels that could result in take for only a short period.
Additionally, required mitigation measures would reduce exposure to
sound that could result in more severe behavioral harassment.
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 mortality or serious injury is anticipated or
authorized;
No Level A harassment (PTS) is anticipated;
Any foraging interruptions are expected to be short term
and unlikely to be cause significantly impacts;
Impacts on marine mammal habitat and species that serve as
prey species for marine mammals are expected to be minimal and the
alternate areas of similar habitat value for marine mammals are readily
available;
Take is anticipated to be primarily Level B behavioral
harassment consisting of brief startling reactions and/or temporary
avoidance of the Project Area;
Survey activities would occur in such a comparatively
small portion of the biologically important areas for north Atlantic
right whale migration, including a small area of designated critical
habitat, that any avoidance of the Project Area due to activities would
not affect migration. In addition, mitigation measures to shut down at
500 m to minimize potential for Level B behavioral harassment would
limit both the number and severity of take of the species.
Similarly, due to the relatively small footprint of the
survey activities in relation to the size of a biologically important
areas for right, humpback, fin, and sei whales foraging, the survey
activities would not affect foraging behavior of this species; and
Proposed mitigation measures, including visual monitoring
and shutdowns, are expected to minimize the intensity of potential
impacts to marine mammals.
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 required monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
Vineyard Wind's proposed HRG survey activities will have a negligible
impact on the affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Sections 101(a)(5)(A) and (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 numbers of marine mammals that we propose for authorization to
be taken, for all species and stocks, would be considered small
relative to the relevant stocks or populations (less than 15 percent
for all species and stocks) as shown in Table 7. 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 preliminarily 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
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
[[Page 7977]]
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (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 NMFS Greater Atlantic
Regional Fisheries Office (GARFO), whenever we propose to authorize
take for endangered or threatened species.
The NMFS Office of Protected Resources Permits and Conservation
Division is proposing to authorize the incidental take of four species
of marine mammals which are listed under the ESA: The North Atlantic
right, fin, sei, and sperm whale. The Permits and Conservation Division
has requested initiation of Section 7 consultation with NMFS GARFO for
the issuance of this IHA. NMFS will conclude the ESA section 7
consultation prior to reaching a determination regarding the proposed
issuance of the authorization.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to Vineyard Wind for conducting marine site
characterization surveys offshore of Massachusetts in the areas of the
Commercial Lease of Submerged Lands for Renewable Energy Development on
the Outer Continental Shelf (OCS-A 0501 and OCS-A 0522) and along
potential submarine cable routes to a landfall location in
Massachusetts, Rhode Island, Connecticut, and New York, from April 1,
2020 through March 31, 2021, provided the previously mentioned
mitigation, monitoring, and reporting requirements are incorporated. A
draft of the proposed IHA can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this Notice of Proposed IHA for the proposed HRG
survey. We also request at this time comment on the potential Renewal
of this proposed IHA as described in the paragraph below. Please
include with your comments any supporting data or literature citations
to help inform decisions on the request for this IHA or a subsequent
Renewal IHA.
On a case-by-case basis, NMFS may issue a one-year Renewal IHA
following notice to the public providing an additional 15 days for
public comments when (1) up to another year of identical or nearly
identical, or nearly identical, activities as described in the
Specified Activities section of this notice is planned or (2) the
activities as described in the Specified Activities section of this
notice would not be completed by the time the IHA expires and a Renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
A request for renewal is received no later than 60 days
prior to the needed Renewal IHA effective date (recognizing that the
Renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA).
The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested Renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for Renewal, the status of the
affected species or stocks, and any other pertinent information, NMFS
determines that there are no more than minor changes in the activities,
the mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: February 5, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2020-02662 Filed 2-11-20; 8:45 am]
BILLING CODE 3510-22-P