Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Phase 2 Construction of the Vineyard Wind 1 Offshore Wind Project Off Massachusetts, 31008-31064 [2024-08434]
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Federal Register / Vol. 89, No. 79 / Tuesday, April 23, 2024 / Notices
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
[RTID 0648–XD687]
Takes of Marine Mammals Incidental to
Specified Activities; Taking Marine
Mammals Incidental to Phase 2
Construction of the Vineyard Wind 1
Offshore Wind Project Off
Massachusetts
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice; proposed incidental
harassment authorization; request for
comments on proposed authorization.
AGENCY:
NMFS has received a request
from Vineyard Wind LLC (Vineyard
Wind) for authorization to take marine
mammals incidental to the completion
of the construction of a commercial
wind energy project offshore
Massachusetts in the northern portion of
Lease Area OCS–A 0501. 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; which
consists of a subset of activities for
which take was authorized previously,
but which Vineyard Wind did not
complete within the effective dates of
the previous IHA. NMFS will consider
public comments prior to making any
final decision on the issuance of the
requested MMPA authorization and
agency responses will be summarized in
the final notice of our decision. The IHA
would be valid for 1 year from date of
issuance.
DATES: Comments and information must
be received no later than May 23, 2024.
ADDRESSES: Comments should be
addressed to Jolie Harrison, Chief,
Permits and Conservation Division,
Office of Protected Resources (OPR),
NMFS and should be submitted via
email to ITP.taylor@noaa.gov. Electronic
copies of the application and supporting
documents, as well as a list of the
references cited in this document, may
be obtained online at: https://
www.fisheries.noaa.gov/national/
marine-mammal-protection/incidentaltake-authorizations-other-energyactivities-renewable. In case of problems
accessing these documents, please call
the contact listed below (see FOR
FURTHER INFORMATION CONTACT).
Instructions: NMFS is not responsible
for comments sent by any other method,
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SUMMARY:
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to any other address or individual, or
received after the end of the comment
period. Comments, including all
attachments, must not exceed a 25megabyte file size. All comments
received are a part of the public record
and will generally be posted online at
https://www.fisheries.noaa.gov/
national/marine-mammal-protection/
incidental-take-authorizations-otherenergy-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:
Jessica Taylor, OPR, NMFS, (301) 427–
8401.
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
proposed or, if the taking is limited to
harassment, a notice of a proposed IHA
is provided to the public for review.
Authorization for incidental takings
shall be granted if NMFS finds that the
taking will have a negligible impact on
the species or stock(s) and will not have
an unmitigable adverse impact on the
availability of the species or stock(s) for
taking for subsistence uses (where
relevant). Further, NMFS must prescribe
the permissible methods of taking and
other ‘‘means of effecting the least
practicable adverse impact’’ on the
affected species or stocks and their
habitat, paying particular attention to
rookeries, mating grounds, and areas of
similar significance, and on the
availability of the species or stocks for
taking for certain subsistence uses
(referred to in shorthand as
‘‘mitigation’’); and requirements
pertaining to the mitigation, monitoring
and reporting of the takings are set forth.
The definitions of all applicable MMPA
statutory terms cited above are included
in the relevant sections below.
National Environmental Policy Act
To comply with the National
Environmental Policy Act of 1969
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(NEPA; 42 U.S.C. 4321 et seq.) and
NOAA Administrative Order (NAO)
216–6A, NMFS must review our
proposed action (i.e., the issuance of an
IHA) with respect to potential impacts
on the human environment. NMFS
participated as a cooperating agency on
the Bureau of Ocean Energy
Management (BOEM) 2021
Environmental Impact Statement (EIS)
for the Vineyard Wind 1 Offshore Wind
Project.
NMFS’ proposal to issue Vineyard
Wind the requested IHA constitutes a
federal action subject to NEPA (42
U.S.C. 4321 et seq.). On May 10, 2021,
NMFS adopted the Bureau of Ocean
Energy Management’s (BOEM) Vineyard
Wind 1Final Environmental Impact
Statement (FEIS), published on March
12, 2021 and available at: https://
www.boem.gov/renewable-energy/stateactivities/vineyard-wind-1. NMFS is
currently evaluating if supplementation
of the Vineyard Wind 1 EIS is required
per 40 CFR 1502.9(d). We will review
all comments submitted in response to
this notice prior to concluding our
NEPA process or making a final
decision on the IHA request.
Summary of Request
On December 15, 2023, NMFS
received a request from Vineyard Wind
for an IHA to take marine mammals
incidental to Phase 2 construction of the
Vineyard Wind Offshore Wind Project
off Massachusetts, specifically wind
turbine generator (WTG) monopile
foundation installation, in the northern
portion of Lease Area OCS–A 0501.
Vineyard Wind completed installation
of 47 WTG monopiles and 1 electrical
service platform (ESP) jacket foundation
in 2023 under an IHA issued by NMFS
on June 25, 2021 (86 FR 33810) with
effective dates from May 1, 2023,
through April 30, 2024. Due to
unexpected delays, Vineyard Wind was
not able to complete pile driving
activities before the expiration date of
the current IHA (April 30, 2024); thus,
Vineyard Wind is requesting take of
marine mammals incidental to installing
the remaining 15 monopiles to complete
foundation installation for the Project.
In total, the Project will consist of 62
WTG monopiles and 1 offshore
substation.
Following NMFS’ review of the
December 2023 application, Vineyard
Wind submitted multiple revised
versions of the application, and it was
deemed adequate and complete on
March 13, 2024. Vineyard Wind’s
request is for take of 14 species of
marine mammals, by Level B
harassment and, for 6 of these species,
Level A harassment. Neither Vineyard
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Wind nor NMFS expect serious injury
or mortality to result from this activity
and, therefore, an IHA is appropriate.
Vineyard Wind previously conducted
high resolution geophysical (HRG) site
characterization surveys within the
Lease Area and associated export cable
corridor in 2016, 2018–2021, and June–
December 2023 (ESS Group Inc., 2016;
Vineyard Wind 2018, 2019; EPI Group,
2021; RPS, 2022; Vineyard Wind 2023a–
f). During the 2023 construction season,
NMFS coordinated closely with
Vineyard Wind to ensure compliance
with their IHA. In a few instances,
NMFS raised concerns with Vineyard
Wind regarding their implementation of
certain required measures. NMFS
worked closely with Vineyard Wind
throughout the construction season to
course correct, where needed, and
ensure compliance with the
requirements (e.g., mitigation,
monitoring, and reporting) of the
previous IHA, and information
regarding their monitoring results may
be found in the Estimated Take of
Marine Mammals section.
Description of Proposed Activity
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Overview
Vineyard Wind proposes to construct
and operate an 800-megawatt (MW)
wind energy facility, the Project, in the
Atlantic Ocean in Lease area OCS–A
0501, offshore of Massachusetts. The
project would consist of up to 62
offshore wind turbine generators
(WTGs), 1 electrical service platform
(ESP), an onshore substation, offshore
and onshore cabling, and onshore
operations and maintenance facilities.
The onshore substation and ESP are
now complete. Installation of 47
monopile foundations was completed
under a current IHA (86 FR 33810, June
25, 2021), effective from May 1, 2023,
through April 30, 2024. However, due to
unexpected, Vineyard Wind will not be
able to complete pile driving activities
before the expiration date of the current
IHA (April 30, 2024). Take of marine
mammals, in the form of behavioral
harassment and limited instances of
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auditory injury, may occur incidental to
the installation of the remaining 15
WTG monopile foundations due to inwater noise exposure resulting from
impact pile driving. The remaining 15
monopile foundations would occur
within a Limited Installation Area (LIA)
(64.3 square kilometers (km2; 15,888.9
acres)) within the Lease Area (264.4 km2
(65,322.4 acres)). Installation of the
remaining 15 monopile foundations is
expected to occur in 2024.
Dates and Duration
The proposed pile driving activities
are planned to occur in 2024 after the
IHA is issued and, while not planned,
may occur in June or July in 2025. Pile
driving activities are estimated to
require approximately 15
nonconsecutive days (30
nonconsecutive hours of pile driving).
Given vessel availability, weather delay,
and logistical constraints, these 15 days
for installation of the remaining
monopile foundations could occur close
in time or spread out over months.
Although installation of a single
monopile may last for several hours,
active pile driving for installation of a
single monopile is expected to last for
a maximum of 2 hours. Up to 1
monopile may be installed per day,
based upon the average pile driving
time (up to 2 hours) for the installation
of the currently installed 47 monopiles.
Monopile foundations would be
installed in batches of three to six
monopiles at a time as this represents
the maximum batch size that the
installation vessel can carry to the LIA.
After installation of a batch of three to
six monopiles, there would be a 4 to 7
day pause in monopile installation to
allow time for the installation vessel to
return with a new batch of monopiles.
No concurrent monopile installation is
proposed. Vineyard Wind has proposed,
and NMFS would require, that pile
driving activities be prohibited from
January 1 through May 31 due to the
increased presence of North Atlantic
right whales (NARWs) in the LIA and
the timing of the project (i.e., pile
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31009
driving in May is not practicable).
NMFS is also proposing to restrict pile
driving in December to the maximum
extent practicable.
Specific Geographic Region
Vineyard Wind’s would construct the
Project in within Federal waters off
Massachusetts, in the northern portion
of the Vineyard Wind Lease Area OCS–
A 0501 (figure 1). This area is also
referred to as the Wind Development
Area (WDA). The 15 remaining
monopiles would be installed in a LIA
within a portion of the southwest corner
of the WDA. The LIA is approximately
70.5 km2 (17,420.9 acres) in size, as
compared to the overall size of the Lease
Area (264.4 km2 (63,322.4 acres)). At its
nearest point, the LIA is approximately
29 kilometers (km; 18.1 miles (mi)) from
the southeast corner of Martha’s
Vineyard and a similar distance from
Nantucket. Water depths in the WDA
range from approximately 37 to 49.5
meters (m; 121–162 feet (ft)). Water
depth and bottom habitat are similar
throughout the Lease Area (Pyc et al.,
2018).
Vineyard Wind’s specified activities
would occur in the Northeast U.S.
Continental Shelf Large Marine
Ecosystem (NES LME), an area of
approximately 260,000 km2 from Cape
Hatteras in the south to the Gulf of
Maine in the north. Specifically, the LIA
is located within the Mid-Atlantic Bight
subarea of the NES LME, which extends
between Cape Hatteras, North Carolina,
and Martha’s Vineyard, Massachusetts,
extending westward into the Atlantic to
the 100-m isobath. The specific
geographic region includes the LIA as
well as the crew transfer vessel transit
corridors (see Proposed Mitigation
section) and cable laying routes. The
installation vessel and support vessels
would conduct approximately three
trips to Canada during the period of the
IHA, transiting from New Bedford and
nearby ports. Figure 1 shows the LIA
and planned locations for the remaining
15 monopiles to be installed.
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70"36'W
70"30'W
70"24'W
BOEM lease Area
0
Scale: 1:115,000
5km
2.5
NAD83 UTM Zone 19N (2011)
2NM
Date: 2024-FE&-29
·~·V
VINEYARD WIND1
·. 70"30'W.
Detailed Description of the Specified
Activity
Monopile Installation
Vineyard Wind proposes to install 15
monopile WTG foundations in the LIA
(figure 1) to complete the Vineyard
Wind Offshore Wind Project (84 FR
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18346, April 30, 2019; 86 FR 33810,
June 25, 2021). Vineyard Wind assumes
all monopile foundations would be
installed using an impact hammer.
Individual monopile installation would
be sequenced according to the numbers
in the cross-hatched area in figure 1.
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A WTG monopile foundation
typically consists of a coated single steel
tubular section, with several sections of
rolled steel plate welded together. Each
13–MW monopile would have a
maximum diameter of 9.6 m (31.5 ft).
WTGs would be arranged in a grid-like
pattern within the LIA with spacing of
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EN23AP24.040
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Figure 1 -- Vineyard Wind Limited Installation Area
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1.9 km (1 nautical mile (nmi)) between
turbines, and driven to a maximum
penetration depth of 28 m (92 ft) to 35
m (115 ft) below the seafloor (Vineyard
Wind, 2023). Monopile foundations
would consist of a monopile with a
separate transition piece.
Monopile foundations would be
installed by a heavy lift vessel. The
installation vessel would upend the
monopile with a crane and place it in
a gripper frame before lowering the
monopile foundation to the seabed (see
figure 4 in IHA application). Vineyard
Wind would use a Monopile Installation
Tool (MPIT) to seat the monopile
foundation and protect against pile
gripper damage as well as risks to
human safety associated with pile run.
The MPIT creates buoyancy within the
monopile foundation using air pressure
to control lowering the monopile
through the pile run risk zone (Vineyard
Wind, 2023). As the monopile
installed per day at a rate of
approximately 2 hours of active pile
driving time per monopile (table 1).
Rock scour protection would be applied
after foundation installation. The scour
protection would be 1–2 m high (3–6 ft),
with stone or rock sizes of
approximately 10–30 centimeters (4–12
inches).
While post-piling activities could be
ongoing at one foundation position as
pile driving is occurring at another
position, no concurrent/simultaneous
pile driving of foundations would occur
(see Dates and Duration section).
Installation of monopile foundations is
anticipated to result in the take of
marine mammals due to noise generated
during pile driving. Proposed
mitigation, monitoring, and reporting
measures are described in detail later in
this document (please see Proposed
Mitigation and Proposed Monitoring
and Reporting).
foundation is lowered, air is released
from the top of the foundation above the
water surface until the pile is stabilized
within the seabed. Once the monopile is
lowered to the seabed, the crane hook
would be released. A hydraulic impact
hammer would be placed on top of the
monopile and used to drive the
monopile into the seabed to the target
penetration depth (28–35 m). Monopile
foundations would be installed using a
maximum hammer energy of 4,000
kilojoules (kJ) (table 1). Pile driving
would begin with a 20-minute soft-start
at reduced hammer energy (see
Proposed Mitigation). The hammer
energy would gradually be increased
based upon resistance experienced from
sediments. Prior to pile driving, the
MPIT process may last from 6 to 15
hours and is dependent upon local soil
conditions at each monopile foundation
(Vineyard Wind, 2023). Vineyard Wind
anticipates that one monopile would be
TABLE 1—IMPACT PILE DRIVING SCHEDULE
Pile type
Project component
9.6-m monopile ......................................................................
WTG ......................................
a Maximum
Max
hammer
energy
(kJ)
I
a 4000
Max piling
time
duration per
pile
(min)
Number of
hammer
strikes
I
b 2,884
I
117
Max piling
time
duration per
day
(min)
I
117
Number
piles/day
1
hammer energy for representative monopiles installed during the 2023 Vineyard Wind Offshore Wind Project construction ranged from 3,227 to 3,831
kJ.
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b Number of hammer strikes based upon the AU–38 representative monopile installed during the 2023 Vineyard Wind Offshore Wind Project construction period at
a maximum hammer energy of 3,825 kJ.
After monopile installation, transition
pieces, containing work platforms and
other ancillary structures, and WTGs,
consisting of a tower and the energygenerating components of the turbine,
would be installed. Transition pieces
and WTGs would be installed on top of
monopile foundations using jack-up
vessels. However, installation of
transition pieces and WTGS on
monopile foundations is not expected to
result in take of marine mammals and,
therefore, are not discussed further.
Vineyard Wind has developed a
sequencing plan for installation of
monopiles throughout the LIA, as
shown in figure 1. The sequencing plan
will allow for several of the monopiles
located in the northeast corner of the
LIA and highest density area of NARWs,
to be installed first.
Vineyard Wind anticipates that it is
possible for the 15 WTGs to become
operational within the effective period
of the IHA. Nine of the 47 WTGs
previously installed in 2023 are
currently operational.
Vessel Operation
Vineyard Wind would use various
types of vessels over the course of the
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1-year proposed IHA for foundation
installation and transporting monopile
batches between ports and the LIA
(table 2). Construction-related vessel
activity is anticipated to include
approximately 20 vessels operating
throughout the specified geographic
area on any given work day. Many of
these vessels would remain in the LIA
for days or weeks at a time, making
infrequent trips to port for bunkering
and provisioning, as needed. Table 2
shows the type and number of vessels
Vineyard Wind would use for various
construction activities as well as the
associated ports. Vineyard Wind would
utilize ports in New London,
Connecticut and New Bedford,
Massachusetts (table 2) to support
offshore construction, crew transfer and
logistics, and other operational
activities. In addition, monopile
foundations would come from a
Canadian port in Halifax. Monopile
foundations would be transported on an
installation vessel to the LIA from
Canada, and would be installed in
batches of three to six monopiles at a
time. Upon completion of installation of
a batch of monopiles, the installation
vessel would return to Canada to load
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an additional batch of monopiles
(Vineyard Wind, 2023). For the
proposed activities, it is expected that
the installation vessel would need to
make a maximum of three trips between
Canada and the LIA.
As part of vessel-based construction
activities, dynamic positioning thrusters
would be utilized to hold vessels in
position or move slowly during
monopile installation. Sound produced
through use of dynamic positioning
thrusters is similar to that produced by
transiting vessels, and dynamic
positioning thrusters are typically
operated either in a similarly
predictable manner or used for short
durations around stationary activities.
Construction-related vessel activity,
including the use of dynamic
positioning thrusters, is not expected to
result in take of marine mammals.
While a vessel strike could cause injury
or mortality of a marine mammal,
Vineyard Wind proposed and NMFS is
proposing to require, extensive vessel
strike avoidance measures that would
avoid vessel strikes from occurring (see
Proposed Mitigation and Proposed
Monitoring and Reporting). Vineyard
Wind did not request, and NMFS
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neither anticipates nor proposes to
authorize, take associated with vessel
activity, and this activity is not analyzed
further.
TABLE 2—TYPE AND NUMBER OF VESSELS ANTICIPATED DURING CONSTRUCTION
Vessel type
Vessel role
Heavy lift vessel .............................
Trans-shipment vessel ...................
Fishing vessel .................................
Pile driving .....................................
Bubble curtain ................................
PSO support vessel .......................
Service operations vessel ..............
Safety vessel ..................................
Crew transfer vessel ......................
Motor vessel ...................................
Inter-Array Cable Laying
Inter-array cables would be installed
to connect WTGs to the ESP. In 2023,
Vineyard Wind completed
approximately 40 percent of the
installation of inter-array cables in the
Lease Area. Vineyard Wind anticipates
approximately 50 percent of the interarray cable laying to take place during
the effective period of the IHA.
Vineyard Wind would perform a pre-lay
grapnel run to remove any obstructions,
such as fishing gear, from the seafloor.
The cable would be laid on the seafloor
and buried using a jet trencher with
scour added for cable protection near
the transition pieces and ESPs. The
sounds associated with cable laying are
consistent with those of routine vessel
operations and not expected to result in
take of marine mammals. Inter-array
cable laying activities are, therefore, not
discussed further.
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Other Activities
Vineyard Wind would not conduct
high-resolution geophysical (HRG)
surveys, UXO/MEC detonation, or
fishery research surveys under this IHA.
Description of Marine Mammals in the
Area of Specified Activities
Thirty-eight marine mammal species,
comprising 39 stocks, under NMFS’
jurisdiction have geographic ranges
within the western North Atlantic OCS
(Hayes et al., 2023). However, for
reasons described below, Vineyard
Wind has requested, and NMFS
proposes to authorize, take of only 14
species (comprising 14 stocks) of marine
mammals. Sections 3 and 4 of the
application summarize available
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Expected
maximum
number of
transits per
month
Maximum
number of
vessels
1
2
2
1
4
2
information regarding status and trends,
distribution and habitat preferences,
and behavior and life history of the
potentially affected species. NMFS fully
considered all of this information, and
we refer the reader to these descriptions,
instead of reprinting the information.
See ADDRESSES. Additional information
regarding population trends and threats
may be found in NMFS’ Stock
Assessment Reports (SARs; https://
www.fisheries.noaa.gov/national/
marine-mammal-protection/marinemammal-stock-assessments) and more
general information about these species
(e.g., physical and behavioral
descriptions) may be found on NMFS’
website (https://www.fisheries.
noaa.gov/find-species).
Table 3 lists all species or stocks for
which take is expected and proposed to
be authorized for this activity and
summarizes information related to the
population or stock, including
regulatory status under the MMPA and
Endangered Species Act (ESA) and
potential biological removal (PBR),
where known. 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’ SARs; 16 U.S.C.
1362(20)). While no serious injury or
mortality is anticipated or proposed to
be authorized here, PBR and annual
serious injury and mortality from
anthropogenic sources are included here
as gross indicators of the status of the
species or stocks and other threats. Four
of the marine mammal species for
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2
4
3
4
2
12
Port
Halifax, Canada.
New London, CT.
New Bedford, MA.
which take is requested are listed as
endangered under the ESA, including
the NARW, fin whale, sei whale, and
sperm whale.
Marine mammal abundance estimates
presented in this document represent
the total number of individuals that
make up a given stock or the total
number estimated within a particular
study or survey area. NMFS’ stock
abundance estimates for most species
represent the total estimate of
individuals within the geographic area,
if known, that comprise 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. 2023 draft SARs and NMFS’
U.S. 2022 SARs. For the majority of
species potentially present in the
specific geographic region, NMFS has
designated only a single generic stock
(e.g., ‘‘western North Atlantic’’) for
management purposes. This includes
the ‘‘Canadian east coast’’ stock of
minke whales, which includes all minke
whales found in United States waters
and is also a generic stock for
management purposes. For humpback
and sei whales, NMFS defines stocks on
the basis of feeding locations (i.e., Gulf
of Maine and Nova Scotia, respectively).
However, references to humpback
whales and sei whales in this document
refer to any individuals of the species
that are found in the specific geographic
region. All values presented in table 3
are the most recent available at the time
of publication and are available online
at: https://www.fisheries.noaa.gov/
national/marine-mammal-protection/
marine-mammal-stock-assessments.
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TABLE 3—MARINE MAMMAL SPECIES THAT MAY OCCUR IN THE LIA AND BE TAKEN BY HARASSMENT
Common name a
Scientific name
ESA/
MMPA
status;
strategic
(Y/N) b
Stock
Stock abundance
(CV, Nmin, most recent
abundance survey) c
Annual M/SI d
PBR
Order Artiodactyla—Cetacea—Mysticeti (baleen whales)
Family Balaenidae:
NARW ..................................
Family
Balaenopteridae
(rorquals):
Fin whale ..............................
Sei whale ..............................
Minke whale .........................
Humpback whale ..................
Eubalaena glacialis ........
Western Atlantic .........................
E, D, Y
340 (0; 337; 2021) e .........
0.7
27.2 f
Balaenoptera physalus ...
Balaenoptera borealis ....
Balaenoptera
acutorostrata.
Megaptera novaeangliae
Western North Atlantic ...............
Nova Scotia ................................
Canadian Eastern Coastal .........
E, D, Y
E, D, Y
-, -, N
11
6.2
170
2.05
0.6
9.4
Gulf of Maine ..............................
-, -, Y
6,802 (0.24, 5,573, 2021)
6,292 (1.02, 3098, 2021)
21,968 (0.31, 17,002,
2021).
1,396 (0, 1,380, 2016) .....
22
12.15
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
Family Physeteridae:
Sperm whale ........................
Family Delphinidae:
Long-finned pilot whale ........
Physeter macrocephalus
North Atlantic ..............................
E, D, Y
5,895 (0.29, 4,639, 2021)
9.28
0.2
Globicephala melas ........
Western North Atlantic ...............
-, -, N
306
5.7
Bottlenose dolphin ................
Tursiops truncatus ..........
Western North Atlantic Offshore
-, -, N
507
28
Common dolphin ..................
Delphinus delphis ...........
Western North Atlantic ...............
-, -, N
1,452
414
Risso’s dolphin .....................
Grampus griseus ............
Western North Atlantic ...............
-, -, N
307
18
Atlantic white-sided dolphin
Lagenorhynchus acutus
Western North Atlantic ...............
-, -, N
39,215 (0.3, 30,627,
2021).
64,587 (0.24, 52,801,
2021) g.
93,100 (0.56, 59,897,
2021).
44,067 (0.19, 30,662,
2021).
93,233 (0.71, 54,443,
2021).
544
28
Phocoena phocoena ......
Gulf of Maine/Bay of Fundy .......
-, -, N
85,765 (0.53, 56,420,
2021).
649
145
-, -, N
61,336 (0.08, 57,637,
2018).
27,911 (0.2, 23,924,
2021).
1,729
339
Family Phocoenidae (porpoises):
Harbor porpoise ...................
Order Carnivora—Pinnipedia
Family Phocidae (earless seals):
Harbor seal ...........................
Gray
seal h
............................
Phoca vitulina .................
Western North Atlantic ...............
Halichoerus grypus .........
Western North Atlantic ...............
-, -, N
I
I
1,512
I
4,570
I
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a Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy’s Committee on Taxonomy
(https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies; Committee on Taxonomy, 2023).
b 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.
c NMFS 2022 marine mammal SARs online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV is the coefficient of variation; Nmin is the minimum estimate of stock abundance.
d 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).
e The draft 2023 SAR includes an estimated population (N
best 340) based on sighting history through December 2021 (89 FR 5495, January 29, 2024). In October
2023, NMFS released a technical report identifying that the NARW population size based on sighting history through 2022 was 356 whales, with a 95 percent credible
interval ranging from 346 to 363 (Linden, 2023).
f Total annual average observed NARW mortality during the period 2017–2021 was 7.1 animals and annual average observed fishery mortality was 4.6 animals.
Numbers presented in this table (27.2 total mortality and 17.6 fishery mortality) are 2016–2020 estimated annual means, accounting for undetected mortality and serious injury.
g As noted in the draft 2023 SAR (89 FR 5495, January 29, 2024), abundance estimates may include sightings of the coastal form.
h NMFS’ stock abundance estimate (and associated PBR value) applies to the U.S. population only. Total stock abundance (including animals in Canada) is approximately 394,311. The annual M/SI value given is for the total stock.
As indicated above, all 14 species
(with 14 managed stocks) in table 3
temporally and spatially co-occur with
the activity to the degree that take is
expected to occur. The following
species are not expected to occur in the
LIA due to their known distributions,
preferred habitats, and/or known
temporal and spatial occurrences: the
blue whale (Balaenoptera musculus),
northern bottlenose whale (Hyperoodon
ampullatus), false killer whale
(Pseudorca crassidens), pygmy killer
whale (Feresa attenuata), melon-headed
whale (Peponocephala electra), dwarf
and pygmy sperm whales (Kogia spp.),
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killer whale (Orcinus orca), Cuvier’s
beaked whale (Ziphius cavirostris), four
species of Mesoplodont whale
(Mesoplodon densitostris, M. europaeus,
M. mirus, and M. bidens), Fraser’s
dolphin (Lagenodelphis hosei), Clymene
dolphin (Stenella clymene), spinner
dolphin (Stenella longirostris), roughtoothed dolphin (Steno bredanensis),
Atlantic spotted dolphin (Stenella
frontalis), pantropical spotted dolphin
(Stenella attenuata), short-finned pilot
whale (Globicephala macrorhynchus),
striped dolphin (Stenella coeruleoalba),
white-beaked dolphin (Lagenorhynchus
albirostris), and hooded seal
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(Crysophora cristata). None of these
species were observed during the 2023
construction season or during previous
site assessment/characterization surveys
(Vineyard Wind, 2018, 2019, 2023a–f).
Due to the lack of sightings of these
species in the MA Wind Energy Area
(WEA) (Kenney and Vigness-Raposa,
2010; ESS Group, Inc., 2016; Kraus et
al., 2016; Vineyard Wind, 2018; 2019;
O’Brien et al., 2020, 2021, 2022, 2023;
EPI Group, 2021; Palka et al., 2017 2021;
RPS, 2022; Vineyard Wind, 2023a–f;
Hayes et al., 2023) as well as
documented habitat preferences and
distributions, we have determined that
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each of these species will not be
considered further. Furthermore, the
northern limit of the northern migratory
coastal stock of the common bottlenose
dolphin (Tursiops truncatus) does not
extend as far north as the LIA. Thus,
take is only proposed for the offshore
stock which may occur within the LIA.
Although harp seals (Pagophilus
groenlandicus) are expected to occur
within the WDA, no harp seals were
observed by Protected Species
Observers (PSOs) during Vineyard
Wind’s site characterization surveys
(2016, 2018–2021; ESS Group, Inc.,
2016; Vineyard Wind, 2018, 2019) nor
during the 2023 construction campaign
(Vineyard Wind, 2023a-f). Thus,
Vineyard Wind did not request, and
NMFS is not proposing to authorize,
take for this species.
In addition to what is included in
sections 3 and 4 of Vineyard Wind’s ITA
application (Vineyard Wind, 2023), the
SARs (https://www.fisheries.noaa.gov/
national/marine-mammal-protection/
marine-mammal-stock-assessments),
and NMFS’ website (https://
www.fisheries.noaa.gov/speciesdirectory/marine-mammals), we
provide further detail below informing
the baseline for select species (e.g.,
information regarding current unusual
mortality events (UMEs) and known
important habitat areas, such as
biologically important areas (BIAs;
https://oceannoise.noaa.gov/
biologically-important-areas) (Van
Parijs, 2015)). There are no ESAdesignated critical habitats for any
species within the LIA (https://
www.fisheries.noaa.gov/resource/map/
national-esa-critical-habitat-mapper).
Any areas of known biological
importance (including the BIAs
identified in LaBrecque et al., 2015) that
overlap spatially (or are adjacent) with
the LIA are addressed in the species
sections below.
Under the MMPA, a UME is defined
as ‘‘a stranding that is unexpected;
involves a significant die-off of any
marine mammal population; and
demands immediate response’’ (16
U.S.C. 1421h(6)). As of January 2024,
three UMEs are occurring along the U.S.
Atlantic coast for NARWs, humpback
whales, and minke whales. Of these, the
most relevant to the LIA are the NARW
and humpback whale UMEs given the
prevalence of these species in Southern
New England (SNE). Below, we include
information for a subset of the species
that presently have an active or recently
closed UME occurring along the
Atlantic coast or for which there is
information available related to areas of
biological significance. More
information on UMEs, including all
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active, closed, or pending, can be found
on NMFS’ website at https://
www.fisheries.noaa.gov/national/
marine-life-distress/active-and-closedunusual-mortality-events.
North Atlantic Right Whale
The NARW has been listed as
Endangered since the ESA’s enactment
in 1973. The species was recently
uplisted from Endangered to Critically
Endangered on the International Union
for Conservation of Nature Red List of
Threatened Species (Cooke, 2020). The
uplisting was due to a decrease in
population size (Pace et al., 2017), an
increase in vessel strikes and
entanglements in fixed fishing gear
(Daoust et al., 2017; Davis & Brillant,
2019; Knowlton et al., 2012; Knowlton
et al., 2022; Moore et al., 2021; Sharp et
al., 2019), and a decrease in birth rate
(Pettis et al., 2022; Reed et al., 2022).
The western Atlantic stock is
considered depleted under the MMPA
(Hayes et al., 2023). There is a recovery
plan (NMFS, 2005) for the NARW, and
NMFS completed 5-year reviews of the
species in 2012, 2017, and 2022, which
concluded no change to the listing
status is warranted.
The NARW population had only a
2.8-percent recovery rate between 1990
and 2011 and an overall abundance
decline of 23.5 percent from 2011 to
2019 (Hayes et al., 2023). Since 2011,
the NARW population has been in
decline; however, the sharp decrease
observed from 2015 to 2020 appears to
have slowed, though the right whale
population continues to experience
annual mortalities above recovery
thresholds (Pace et al., 2017; Pace et al.,
2021; Linden, 2023). NARW calving
rates dropped from 2017 to 2020 with
zero births recorded during the 2017–
2018 season. The 2020–2021 calving
season had the first substantial calving
increase in 5 years with 20 calves born
(including 2 mortalities) followed by 15
calves during the 2021–2022 calving
season and 12 births (including 1
mortality) in 2022–2023 calving season.
These data demonstrate that birth rates
are increasing. However, mortalities
continue to outpace births (Linden,
2023). Best estimates indicate fewer
than 70 reproductively active females
remain in the population and adult
females experience a lower average
survival rate than males (Linden, 2023).
In 2023, the total annual average
observed NARW mortality increased
from 8.1 (which represents 2016–2020)
to 31.2 (which represents 2015–2019),
however, this updated estimate also
accounts for undetected mortality and
serious injury (Hayes et al., 2023).
Although the predicted number of
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Sfmt 4703
deaths from the population are lower in
recent years (2021–2022) when
compared to the high number of deaths
from 2014 to 2020, suggesting a shortterm increase in survival, annual
mortality rates still exceed PBR (Linden,
2023).
NMFS’ regulations at 50 CFR 224.105
designated Seasonal Management Areas
(SMAs) for NARWs in 2008 (73 FR
60173, October 10, 2008). SMAs were
developed to reduce the threat of
collisions between vessels and NARWs.
A portion of the Block Island SMA,
which occurs off Block Island, Rhode
Island, is near the LIA (approximately
4.3 km (2.7 mi) southwest of the OCS–
A 0501 Lease Area at the closest point),
but does not overlap spatially with the
Lease Area or LIA. This SMA is active
from November 1 through April 30 of
each year, and may be used by NARWs
for migrating and/or feeding. As noted
below, NMFS is proposing changes to
the NARW speed rule (87 FR 46921,
August 1, 2022). NMFS has designated
critical habitat for NARWs (81 FR 4838,
January 27, 2016), along the U.S.
southeast coast for calving as well as in
the northeast, just east of the LIA. The
LIA both spatially and temporally
overlaps a portion of a migratory
corridor BIA (LaBrecque et al., 2015).
Due to the current status of NARWs and
the spatial proximity of the proposed
project with areas of biological
significance, (i.e., a migratory corridor,
SMA), the potential impacts of the
proposed project on NARWs warrant
particular attention.
NARWs range from calving grounds
in the southeastern United States to
feeding grounds in New England waters
and into Canadian waters (Hayes et al.,
2023). Surveys have demonstrated the
existence of seven areas where NARWs
congregate seasonally in Georges Bank,
off Cape Cod, and in Massachusetts Bay
(Hayes et al., 2023). In late fall (i.e.,
November), a portion of the NARW
population (including pregnant females)
typically departs the feeding grounds in
the North Atlantic, moves south along
the migratory corridor BIA, including
through the LIA, to calving grounds off
Georgia and Florida. This movement is
followed by a northward migration
(primarily mothers with young calves)
into northern feeding areas in March
and April (LaBrecque et al., 2015; Van
Parijs, 2015). Recent research indicates
our understanding of their movement
patterns remains incomplete and not all
of the population undergoes a consistent
annual migration (Davis et al., 2017;
Gowan et al., 2019; Krzystan et al.,
2018). Non-calving females may remain
in the feeding grounds during the winter
in the years preceding and following the
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birth of a calf to increase their energy
stores (Gowen et al., 2019). NARWs may
migrate through the LIA to access more
northern feeding grounds or southern
calving grounds.
NARWs may occur year-round in
SNE, near Martha’s Vineyard and
Nantucket Shoals as well as throughout
the Massachusetts and Rhode Island/
Massachusetts Wind Energy Areas (MA
and RI/MA WEAs) (Quintan-Rizzo et al.,
2021; O’Brien et al., 2023; Van Parijs et
al., 2023). Kraus et al. (2016) found
acoustic detections in SNE to peak
during the winter and early spring
(January through March). Visual surveys
(Quintana-Rizzo et al., 2021) have also
confirmed the abundance of NARWs in
SNE to be the highest during the winter
and spring (January through May),
although peaks in acoustic detections
may vary seasonally across years
(Quintana-Rizzo et al., 2021; Estabrook
et al., 2022). Distribution throughout
SNE may vary seasonally with NARW
occurrence being closest to the LIA
during the spring (Quintana-Rizzo et al.,
2021). Van Parijs et al. (2023) monitored
acoustic detections of baleen whales
throughout SNE and detected NARWs
near the LIA from January through May.
Acoustic detections began to increase
near the LIA in November and further
increased into December (Van Parijs et
al., 2023).
An 8-year analysis of NARW sightings
within SNE showed that the NARW
distribution has been shifting
(Quintana-Rizzo et al., 2021). NARWs
feed primarily on the copepod, Calanus
finmarchicus, a species whose
availability and distribution has
changed both spatially and temporally
over the last decade due to an
oceanographic regime shift that has
been ultimately linked to climate
change (Meyer-Gutbrod et al., 2021;
Record et al., 2019; Sorochan et al.,
2019). This distribution change in prey
availability has led to shifts in NARW
habitat-use patterns over the same time
period (Davis et al., 2020; MeyerGutbrod et al., 2022; Quintano-Rizzo et
al., 2021; O’Brien et al., 2022; Pendleton
et al., 2022; Van Parijs et al., 2023), with
reduced use of foraging habitats in the
Great South Channel and Bay of Fundy
and increased use of habitats within
Cape Cod Bay and a region south of
Martha’s Vineyard and Nantucket
Islands (Stone et al., 2017; Mayo et al.,
2018; Ganley et al., 2019; Record et al.,
2019; Meyer-Gutbrod et al., 2021; Van
Parijs et al., 2023). Pendleton et al.
(2022) observed shifts in the timing of
NARW peak habitat use in Cape Cod
Bay during the spring, likely in response
to changing seasonal conditions, and
characterized SNE as a ‘‘waiting room’’
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for NARWs in the spring, providing
sufficient, although sub-optimal, prey
choices while the NARWs wait for
foraging conditions in Cape Cod Bay
(and other primary foraging grounds
such as the Great South Channel) to
optimize as seasonal primary and
secondary production progresses.
While Nantucket Shoals is not
designated as critical NARW habitat, its
importance as a foraging habitat is well
established (Leiter et al., 2017;
Quintana-Rizzo et al., 2021; Estabrook et
al., 2022; O’Brien et al., 2022).
Nantucket Shoals’ unique
oceanographic and bathymetric features,
including a persistent tidal front, help
sustain year-round elevated
phytoplankton biomass, and aggregate
zooplankton prey for NARWs
(Quintana-Rizzo et al., 2021). SNE
serves as a foraging habitat throughout
the year, although not to the extent
provided seasonally in more wellunderstood feeding habitats like Cape
Cod Bay in late spring, the Great South
Channel, and the Gulf of St. Lawrence
(O’Brien et al., 2022). A BIA for foraging
(LaBrecque et al., 2015) within Cape
Cod Bay is approximately 71 km (44.1
mi) north of the LIA, while critical
habitat northeast of Martha’s Vineyard
and Nantucket Island is within 56 km
(34.8 mi). SNE also represents
socializing habitat for NARWs as Leiter
et al. (2017) documented surface active
groups (SAGs), indicative of socializing
behavior, year-round in SNE.
Observations of NARW transitions in
habitat use, variability in seasonal
presence in identified core habitats, and
utilization of habitat outside of
previously focused survey effort
prompted the formation of a NMFS’
Expert Working Group, which identified
current data collection efforts, data gaps,
and provided recommendations for
future survey and research efforts
(Oleson et al., 2020). In addition,
extensive data gaps that were
highlighted in a recent report by the
National Academy of Sciences (NAS,
2023) have prevented development of a
thorough understanding of NARW
foraging ecology in the Nantucket
Shoals region. However, it is clear that
the habitat was historically valuable to
the species, given that the whaling
industry capitalized on consistent
NARW occurrence there, and has again
become increasingly so over the last
decade.
Since 2017, 125 dead, seriously
injured, or sublethally injured or ill
NARWs along the United States and
Canadian coasts have been documented,
necessitating a UME declaration in 2017
and subsequent investigation. The
leading category for the cause of death
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31015
for this ongoing UME is ‘‘human
interaction,’’ specifically from
entanglements or vessel strikes. As of
April 9, 2024, there have been 39
confirmed mortalities, 1 pending
mortality (dead, stranded, or floaters),
and 34 seriously injured free-swimming
whales for a total of 73 whales.
Beginning on October 14, 2022, the
UME also considers animals with
sublethal injury or illness bringing the
total number of whales in the UME to
125. Approximately 42 percent of the
population is known to be in reduced
health (Hamilton et al., 2021) likely
contributing to smaller body sizes at
maturation, making them more
susceptible to threats and reducing
fecundity (Moore et al., 2021; Reed et
al., 2022; Stewart et al., 2022; Pirotta et
al., 2024). Pirotta et al. (2024) found an
association between the decreased mean
length of female NARWs and reduced
calving probability. More information
about the NARW UME is available
online at https://www.fisheries.
noaa.gov/national/marine-life-distress/
2017-2024-north-atlantic-right-whaleunusual-mortality-event.
On August 1, 2022, NMFS announced
proposed changes to the existing NARW
vessel speed regulations to further
reduce the likelihood of mortalities and
serious injuries to endangered right
whales from vessel collisions, which are
a leading cause of the species’ decline
and a primary factor in the ongoing
Unusual Mortality Event (87 FR 46921,
August 1, 2022). Should a final vessel
speed rule be issued and become
effective during the effective period of
this IHA (or any other MMPA incidental
take authorization), the authorization
holder would be required to comply
with any and all applicable
requirements contained within the final
rule. Specifically, where measures in
any final vessel speed rule are more
protective or restrictive than those in
this or any other MMPA authorization,
authorization holders would be required
to comply with the requirements of the
rule. Alternatively, where measures in
this or any other MMPA authorization
are more restrictive or protective than
those in any final vessel speed rule, the
measures in the MMPA authorization
would remain in place. These changes
would become effective immediately
upon the effective date of any final
vessel speed rule and would not require
any further action on NMFS’s part.
Humpback Whale
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
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be listed as endangered. On September
8, 2016, NMFS divided the once single
species into 14 distinct population
segments (DPS), removed the specieslevel 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 whales that is
expected to occur in the LIA. Bettridge
et al. (2015) estimated the size of the
West Indies DPS population at 12,312
(95 percent confidence interval 8,688–
15,954) whales in 2004–2005, which is
consistent with previous population
estimates of approximately 10,000–
11,000 whales (Stevick et al., 2003;
Smith et al., 1999) and the increasing
trend for the West Indies DPS (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
been sighted repeatedly within the same
winter season, indicating that not all
humpback whales migrate south every
winter (Hayes et al., 2018).
Kraus et al. (2016) conducted aerial
surveys from 2011–2015 in SNE and
observed humpback whales during all
seasons, yet humpback whales were
observed most often during the spring
and summer. The greatest number of
sightings occurred during the month of
April (n=33) (Kraus et al., 2016). Calves,
feeding behavior, and courtship
behavior were observed as well. More
recent studies (O’Brien et al., 2020,
2021, 2022, 2023) confirm that
humpback whales peak in abundance in
the LIA during spring and summer, with
the majority of sightings year-round
occurring in the eastern portion of the
MA and RI/MA WEAs and near the
Nantucket Shoals area (O’Brien et al.,
2020). O’Brien et al. (2022) identified
seasonal distribution patterns of
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humpback whales throughout SNE with
more concentrated sightings near
Nantucket Shoals in the fall and
sightings being distributed more evenly
across the MA and RI/MA WEAs during
spring and summer. As observed during
the 2011–2015 surveys, O’Brien et al.
(2023) also observed feeding behavior
and mother/calf pairs throughout the
spring and summer. Van Parijs et al.
(2023) detected humpback whales near
the LIA mainly from November through
June. During the Vineyard Wind 2023
construction campaign, visual and
acoustic detections of humpback whales
occurred mainly from June through
October, with the greatest detections
occuring in October (Vineyard Wind,
2023).
The LIA does not overlap with any
BIAs or other important areas for the
humpback whales. A humpback whale
feeding BIA extends throughout the Gulf
of Maine, Stellwagen Bank, and Great
South Channel from May through
December, annually (LaBrecque et al.,
2015). This BIA is located
approximately 73 km (45.5 mi)
northeast of the Lease Area and would
not likely be impacted by project
activities.
Since January 2016, elevated
humpback whale mortalities along the
Atlantic coast from Maine to Florida led
to the declaration of a UME in April
2017. As of April 9, 2024, 218
humpback whales have stranded as part
of this UME. Partial or full necropsy
examinations have been conducted on
approximately 90 of the known cases.
Of the whales examined, about 40
percent had evidence of human
interaction, either ship strike or
entanglement. While a portion of the
whales have shown evidence of premortem vessel strike, this finding is not
consistent across all whales examined
and more research is needed. Since
January 1, 2023, 43 humpbacks have
stranded along the east coast of the
United States (7 of these whales have
stranded off Massachusetts). These
whales may have been following their
prey (small fish) which were reportedly
close to shore this past winter. These
prey also attract fish that are targeted by
recreational and commercial fishermen,
which increases the number of boats in
these areas. More information is
available at https://www.fisheries.
noaa.gov/national/marine-life-distress/
active-and-closed-unusual-mortalityevents.
Fin Whale
Fin whales frequently occur in the
waters of the U.S. Atlantic Exclusive
Economic Zone (EEZ), principally from
Cape Hatteras, North Carolina
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northward and are distributed in both
continental shelf and deep-water
habitats (Hayes et al., 2023). Although
fin whales are present north of the 35degree latitude north region in every
season and are broadly distributed
throughout the western North Atlantic
for most of the year, densities vary
seasonally (Edwards et al., 2015; Hayes
et al., 2023). Fin whales typically feed
in the Gulf of Maine and the waters
surrounding New England, but their
mating and calving (and general
wintering) areas are largely unknown
(Hain et al., 1992; Hayes et al., 2023).
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., 2022).
New England waters represent a major
feeding ground for fin whales, and fin
whale feeding BIAs occur offshore of
Montauk Point, New York, from March
to October (2,933 km2) (Hain et al.,
1992; LaBrecque et al., 2015) and yearround in the southern Gulf of Maine
(18,015 km2). Aerial surveys conducted
from 2011–2015 in SNE documented fin
whale occurrence in every season, with
the greatest numbers of sightings during
the spring (n=35) and summer (n=49)
months (Kraus et al., 2016). Fin whale
distribution varied seasonally, with fin
whales occurring in the southern
regions of the MA and RI/MA WEAs
during spring and closer to northern
regions of the WEAs during summer
(Kraus et al., 2016). More recent surveys
have documented fin whales throughout
winter, spring, and summer (O’Brien et
al., 2020, 2021, 2022, 2023) with the
greatest abundance occurring during the
summer and clustered in the western
portion of the WEAs (O’Brien et al.,
2023). Acoustic detection of fin whales
in SNE indicate fin whale presence in
the area from August through April and,
sporadically, from May through July
(Parijs et al., 2023). During the 2023
construction campaign, Vineyard Wind
detected fin whales from June through
December (with the exception of
August), with the most detections
occurring in October (Vineyard Wind,
2023). Based upon observations of
feeding behavior and the close
proximity of the Lease Area to the
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feeding BIAs (8.0 km (5.0 mi) and 76.4
km (47.5 mi) to the Montauk Point and
southern Gulf of Maine BIAs,
respectively) fin whales may use the
LIA for foraging as well as migrating.
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Minke Whale
Minke whales are common and
widely distributed throughout the U.S.
Atlantic EEZ (Cetacean and Turtle
Assessment Program (CETAP), 1982;
Hayes et al., 2022), although their
distribution has a strong seasonal
component. Individuals have often been
detected acoustically in shelf waters
from spring to fall and more often
detected in deeper offshore waters from
winter to spring (Risch et al., 2013).
Minke whales are abundant in New
England waters from May through
September (Pittman et al., 2006; Waring
et al., 2014), yet largely absent from
these areas during the winter, suggesting
the possible existence of a migratory
corridor (LaBrecque et al., 2015). A
migratory route for minke whales
transiting between northern feeding
grounds and southern breeding areas
may exist to the east of the LIA, as
minke whales may track warmer waters
along the continental shelf while
migrating (Risch et al., 2014). Risch et
al. (2014) suggests the presence of a
minke whale breeding ground offshore
of the southeastern US during the
winter.
There are two minke whale feeding
BIAs identified in the southern and
southwestern section of the Gulf of
Maine, including Georges Bank, the
Great South Channel, Cape Cod Bay and
Massachusetts Bay, Stellwagen Bank,
Cape Anne, and Jeffreys Ledge from
March through November, annually
(LaBrecque et al., 2015). The nearest
BIA is approximately 44.0 km (27.3 mi)
northeast of the Lease Area. Due to the
close proximity of the BIA, minke whale
feeding may occur within the LIA.
Although minke whales are sighted in
every season in SNE (O’Brien et al.,
2022), minke whale use of the area is
highest during the months of March
through September (Kraus et al., 2016;
O’Brien et al., 2023). Large feeding
aggregations of humpback, fin, and
minke whales have been observed
during the summer (O’Brien et al.,
2023), suggesting the LIA may serve as
a supplemental feeding grounds for
these species. Acoustic detections data
support visual sighting data, and
indicate minke whale presence in SNE
from March through June and August
through late November/early December
and, sporadically, in January (Parijs et
al., 2023). During the 2023 construction
campaign, Vineyard Wind detected
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minke whales from June through August
(Vineyard Wind, 2023).
From 2017 through 2024, elevated
minke whale mortalities detected along
the Atlantic coast from Maine through
South Carolina resulted in the
declaration of a UME in 2018. As of
April 9, 2024, a total of 166 minke
whale mortalities have occurred during
this UME. Full or partial necropsy
examinations were conducted on more
than 60 percent of the whales.
Preliminary findings in several of the
whales have shown evidence of human
interactions or infectious disease, but
these findings are not consistent across
all of the minke whales examined, so
more research is needed. More
information is available at https://
www.fisheries.noaa.gov/national/
marine-life-distress/2017-2022-minkewhale-unusual-mortality-event-alongatlantic-coast.
Sei Whale
The Nova Scotia stock of sei whales
can be found in deeper waters of the
continental shelf edge of the eastern
United States and northeastward to
south of Newfoundland (Mitchell, 1975;
Hain et al., 1985; Hayes et al., 2022).
During spring and summer, the stock is
mainly concentrated in northern feeding
areas, including the Scotian Shelf
(Mitchell and Chapman, 1977), the Gulf
of Maine, Georges Bank, the Northeast
Channel, and south of Nantucket
(CETAP, 1982; Kraus et al., 2016;
Roberts et al., 2016; Palka et al., 2017;
Cholewiak et al., 2018; Hayes et al.,
2022). Sei whales have been detected
acoustically along the Atlantic
Continental Shelf and Slope from south
of Cape Hatteras, North Carolina to the
Davis Strait, with acoustic occurrence
increasing in the mid-Atlantic region
since 2010 (Davis et al., 2020). Sei
whale migratory movements are not
well understood. In June and July, sei
whales are believed to migrate north
from SNE to feeding areas in eastern
Canada, and south in September and
October to breeding areas (Mitchell,
1975; CETAP, 1982; Davis et al., 2020).
Sei whales generally occur offshore;
however, individuals may also move
into shallower, more inshore waters
(Payne et al., 1990; Halpin et al., 2009;
Hayes et al., 2022). A sei whale feeding
BIA occurs in New England waters from
May through November, approximately
101.4 km (63 mi) east of the LIA
(LaBrecque et al., 2015).
Aerial surveys conducted from 2011–
2015 in SNE observed sei whales
between March and June, with the
greatest number of sightings occurring
in May (n=8) and June (n=13), and no
sightings from July through January
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(Kraus et al., 2016). Acoustic detections
confirm peak occurrences of sei whales
in SNE from early spring and through
mid-summer (March through July)
(Davis et al., 2020). In addition, Van
Parijs et al. (2023) acoustically detected
sei whales near the LIA during the
months of February and August.
However, Davis et al. (2020)
acoustically detected sei whales in SNE
year-round, suggesting this area is an
important habitat for sei whales. As sei
whales are known to target the prey
such as copepods (C. finmarchicus),
which are abundant in SNE waters
(Quintana-Rizzo et al., 2018), SNE likely
represents a supplemental foraging area
for sei whales as well.
Phocid Seals
Harbor and gray seals have
experienced multiple UMEs since 2018.
From June through July 2022, elevated
numbers of harbor seal and gray seal
mortalities occurred across the southern
and central coast of Maine. This event
was declared a UME. During the event,
181 seals stranded. Based upon
necropsy, histopathology, and
diagnostic findings, this UME was
attributed to spillover events of the
highly pathogenic avian influenza from
infected birds to harbor and gray seals.
While the UME did not occur in the
LIA, the populations that were affected
by the UME are the same as those
potentially affected by the project. This
UME has recently been closed.
Information on this UME is available
online at https://www.fisheries.
noaa.gov/2022-2023-pinniped-unusualmortality-event-along-maine-coast.
The above event was preceded by a
different UME, occurring from 2018 to
2020 (closure of the 2018–2020 UME is
pending). Beginning in July 2018,
elevated numbers of harbor seal and
gray seal mortalities occurred across
Maine, New Hampshire, and
Massachusetts. Additionally, stranded
seals have shown clinical signs as far
south as Virginia, although not in
elevated numbers, therefore the UME
investigation encompassed all seal
strandings from Maine to Virginia. A
total of 3,152 reported strandings (of all
species) occurred from July 1, 2018,
through March 13, 2020. Full or partial
necropsy examinations have been
conducted on some of the seals and
samples have been collected for testing.
Based on tests conducted thus far, the
main pathogen found in the seals is
phocine distemper virus. NMFS is
performing additional testing to identify
any other factors that may be involved
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in this UME, which is pending closure.
Information on this UME is available
online at: https://www.fisheries.
noaa.gov/new-england-mid-atlantic/
marine-life-distress/2018-2020pinniped-unusual-mortality-eventalong.
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. 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, 2019) recommended that marine
mammals be divided into hearing
groups based on directly measured
(behavioral or auditory evoked potential
techniques) or estimated hearing ranges
(behavioral response data, anatomical
modeling, etc.). 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-decibel
(dB) threshold from the normalized
composite audiograms, with the
exception for lower limits for lowfrequency 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 4.
TABLE 4—MARINE MAMMAL HEARING GROUPS
[NMFS, 2018]
Generalized hearing
range *
Hearing group
Low-frequency (LF) cetaceans (baleen whales) .....................................................................................................................
Mid-frequency (MF) cetaceans (dolphins, toothed whales, beaked whales, bottlenose whales) ...........................................
High-frequency (HF) cetaceans (true porpoises, Kogia, river dolphins, Cephalorhynchid, Lagenorhynchus cruciger & L.
australis).
Phocid pinnipeds (PW) (underwater) (true seals) ...................................................................................................................
Otariid pinnipeds (OW) (underwater) (sea lions and fur seals) ..............................................................................................
7 Hz to 35 kHz.
150 Hz to 160 kHz.
275 Hz to 160 kHz.
50 Hz to 86 kHz.
60 Hz to 39 kHz.
* 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 the ∼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
(Hemila¨ et al., 2006; Kastelein et al.,
2009; Reichmuth et al., 2013).
For more detail concerning these
groups and associated frequency ranges,
please see NMFS (2018) for a review of
available information.
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Potential Effects of Specified Activities
on Marine Mammals and Their Habitat
This section provides a discussion of
the ways in which components of the
specified activity may impact marine
mammals and their habitat. The
Estimated Take of Marine Mammals
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 of Marine Mammals
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 whether those
impacts are reasonably expected to, or
reasonably likely to, adversely affect the
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species or stock through effects on
annual rates of recruitment or survival.
Vineyard Wind has requested, and
NMFS proposes to authorize, the take of
marine mammals incidental to the
construction activities associated with
the LIA. In their application, Vineyard
Wind presented their analyses of
potential impacts to marine mammals
from the acoustic sources. NMFS
carefully reviewed the information
provided by Vineyard Wind, as well as
independently reviewed applicable
scientific research and literature and
other information to evaluate the
potential effects of the Project’s
activities on marine mammals.
The proposed activities would result
in the construction and placement of 15
permanent foundations to support
WTGs. There are a variety of types and
degrees of effects to marine mammals,
prey species, and habitat that could
occur as a result of the Project. Below
we provide a brief description of the
types of sound sources that would be
generated by the project, the general
impacts from these types of activities,
and an analysis of the anticipated
impacts on marine mammals from the
project, with consideration of the
proposed mitigation measures.
Description of Sound Sources
This section contains a brief technical
background on sound, on the
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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: Au and
Hastings, 2008; Richardson et al., 1995;
Urick, 1983; as well as the Discovery of
Sound in the Sea (DOSITS) website at
https://www.dosits.org. Sound is a
vibration that travels as an acoustic
wave through a medium such as a gas,
liquid, or solid. Sound waves alternately
compress and decompress the medium
as the wave travels. These compressions
and decompressions are detected as
changes in pressure by aquatic life and
man-made sound receptors such as
hydrophones (underwater
microphones). In water, sound waves
radiate in a manner similar to ripples on
the surface of a pond and may be either
directed in a beam (narrow beam or
directional sources) or sound beams
may radiate in all directions
(omnidirectional sources).
Sound travels in water more
efficiently than almost any other form of
energy, making the use of acoustics
ideal for the aquatic environment and
its inhabitants. In seawater, sound
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travels at roughly 1,500 meters per
second (m/s). In-air, sound waves travel
much more slowly, at about 340 m/s.
However, the speed of sound can vary
by a small amount based on
characteristics of the transmission
medium, such as water temperature and
salinity. Sound travels in water more
efficiently than almost any other form of
energy, making the use of acoustics
ideal for the aquatic environment and
its inhabitants. In seawater, sound
travels at roughly 1,500 m/s. In-air,
sound waves travel much more slowly,
at about 340 m/s. However, the speed of
sound can vary by a small amount based
on characteristics of the transmission
medium, such as water temperature and
salinity.
The basic components of a sound
wave 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.
The intensity (or amplitude) of
sounds is measured in dB, which is a
relative unit of measurement that is
used to express the ratio of one value of
a power or field to another. Decibels are
measured on a logarithmic scale, so a
small change in dB corresponds to large
changes in sound pressure. For
example, a 10-dB increase is a ten-fold
increase in acoustic power. A 20-dB
increase is then a hundred-fold increase
in power and a 30-dB increase is a
thousand-fold increase in power.
However, a ten-fold increase in acoustic
power does not mean that the sound is
perceived as being 10 times louder.
Decibels are a relative unit comparing
two pressures; therefore, a reference
pressure must always be indicated. For
underwater sound, this is 1 microPascal
(mPa). For in-air sound, the reference
pressure is 20 microPascal (mPa). The
amplitude of a sound can be presented
in various ways; however, NMFS
typically considers three metrics. In this
proposed IHA, all decibel levels are
referenced to (re) 1mPa.
Sound exposure level (SEL)
represents the total energy in a stated
frequency band over a stated time
interval or event and considers both
amplitude and duration of exposure
(represented as dB re 1 mPa2 -s). SEL is
a cumulative metric; it can be
accumulated over a single pulse (for pile
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driving this is often referred to as singlestrike SEL; SELss) or calculated over
periods containing multiple pulses
(SELcum). Cumulative SEL represents the
total energy accumulated by a receiver
over a defined time window or during
an event. The SEL metric is useful
because it allows sound exposures of
different durations to be related to one
another in terms of total acoustic
energy. The duration of a sound event
and the number of pulses, however,
should be specified as there is no
accepted standard duration over which
the summation of energy is measured.
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 (Urick, 1983). 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.
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. Along with SEL,
this metric is used in evaluating the
potential for permanent threshold shift
(PTS) and temporary threshold shift
(TTS).
Sounds can be either impulsive or
non-impulsive. 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 NMFS
et al. (2018) and Southall et al. (2007,
2019a) for an in-depth discussion of
these concepts. Impulsive sound
sources (e.g., airguns, explosions,
gunshots, sonic booms, impact pile
driving) produce signals that are brief
(typically considered to be less than 1
second), broadband, atonal transients
(American National Standards Institute
(ANSI), 1986; ANSI, 2005; Harris, 1998;
National Institute for Occupational
Safety and Health (NIOSH), 1998;
International Organization for
Standardization (ISO), 2003) and occur
either as isolated events or repeated in
some succession. Impulsive sounds are
all characterized by a relatively rapid
rise from ambient pressure to a maximal
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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. Impulsive sounds
are typically intermittent in nature.
Non-impulsive sounds can be tonal,
narrowband, or broadband, brief, or
prolonged, and may be either
continuous or intermittent (ANSI, 1995;
NIOSH, 1998). Some of these nonimpulsive sounds can be transient
signals of short duration but without the
essential properties of pulses (e.g., rapid
rise time). Examples of non-impulsive
sounds include those produced by
vessels, aircraft, machinery operations
such as drilling or dredging, vibratory
pile driving, and active sonar systems.
Sounds are also characterized by their
temporal component. Continuous
sounds are those whose sound pressure
level remains above that of the ambient
sound with negligibly small fluctuations
in level (NIOSH, 1998; ANSI, 2005)
while intermittent sounds are defined as
sounds with interrupted levels of low or
no sound (NIOSH, 1998). NMFS
identifies Level B harassment thresholds
based on if a sound is continuous or
intermittent.
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
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 Hz and 50 kHz (International
Council for the Exploration of the Sea
(ICES), 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
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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 dB from day to day
(Richardson et al., 1995). The result is
that, depending on the source type and
its intensity, sound from a specified
activity may be a negligible addition to
the local environment or could form a
distinctive signal that may affect marine
mammals. Human-generated sound is a
significant contributor to the acoustic
environment in the project location.
Potential Effects of Underwater Sound
on Marine Mammals
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. Broadly,
underwater sound from active acoustic
sources, such as those in the Project, 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., 2003; Nowacek et al.,
2007; Southall et al., 2007; Go¨tz et al.,
2009). 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
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include neurological effects, bubble
formation, resonance effects, and other
types of organ or tissue damage (Cox et
al., 2006; Southall et al., 2007; Zimmer
and Tyack, 2007; Tal et al., 2015).
In general, the degree of effect of an
acoustic exposure is intrinsically related
to the signal characteristics, received
level, distance from the source, and
duration of the sound exposure, in
addition to the contextual factors of the
receiver (e.g., behavioral state at time of
exposure, age class, etc.). In general,
sudden, high-level sounds can cause
hearing loss as can longer exposures to
lower-level sounds. Moreover, any
temporary or permanent loss of hearing
will occur almost exclusively for noise
within an animal’s hearing range. We
describe below the specific
manifestations of acoustic effects that
may occur based on the activities
proposed by Vineyard Wind.
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 (at the greatest
distance) 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 (closer to the receiving
animal) corresponds with the area
where the signal is audible to the animal
and of sufficient intensity to elicit
behavioral or physiological
responsiveness. The 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.
Below, we provide additional detail
regarding potential impacts on marine
mammals and their habitat from noise
in general, starting with hearing
impairment, as well as from the specific
activities Vineyard Wind plans to
conduct, to the degree it is available
(noting that there is limited information
regarding the impacts of offshore wind
construction on marine mammals).
Hearing Threshold Shift
Marine mammals exposed to highintensity sound or to lower-intensity
sound for prolonged periods can
experience hearing threshold shift (TS),
which NMFS defines as a change,
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usually an increase, in the threshold of
audibility at a specified frequency or
portion of an individual’s hearing range
above a previously established reference
level expressed in decibels (NMFS,
2018). Threshold shifts can be
permanent, in which case there is an
irreversible increase in the threshold of
audibility at a specified frequency or
portion of an individual’s hearing range
or temporary, in which there is
reversible increase in the threshold of
audibility at a specified frequency or
portion of an individual’s hearing range
and the animal’s hearing threshold
would fully recover over time (Southall
et al., 2019a). Repeated sound exposure
that leads to TTS could cause PTS.
When PTS occurs, there can be
physical damage to the sound receptors
in the ear (i.e., tissue damage) whereas
TTS represents primarily tissue fatigue
and is reversible (Henderson et al.,
2008). 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; Southall et al., 2019a). 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. However, such
relationships are assumed to be similar
to those in humans and other terrestrial
mammals. Noise exposure can result in
either a permanent shift in hearing
thresholds from baseline (a 40–dB
threshold shift approximates a PTS
onset; e.g., Kryter et al., 1966; Miller,
1974; Henderson et al., 2008) or a
temporary, recoverable shift in hearing
that returns to baseline (a 6–dB
threshold shift approximates a TTS
onset; e.g., Southall et al., 2019a). Based
on data from terrestrial mammals, a
precautionary assumption is that the
PTS thresholds, expressed in the
unweighted peak sound pressure level
metric (PK), for impulsive sounds (such
as impact pile driving pulses) are at
least 6 dB higher than the TTS
thresholds and the weighted PTS
cumulative sound exposure level
thresholds are 15 (impulsive sound) to
20 (non-impulsive sounds) dB higher
than TTS cumulative sound exposure
level thresholds (Southall et al., 2019a).
Given the higher level of sound or
longer exposure duration necessary to
cause PTS as compared with TTS, PTS
is less likely to occur as a result of these
activities; however, it is possible, and a
small amount has been proposed for
authorization for several species.
TTS is the mildest form of hearing
impairment that can occur during
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exposure to sound, with a TTS of 6 dB
considered the minimum threshold shift
clearly larger than any day-to-day or
session-to-session variation in a
subject’s normal hearing ability
(Schlundt et al., 2000; Finneran et al.,
2000; Finneran et al., 2002). 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. There is
data on sound levels and durations
necessary to elicit mild TTS for marine
mammals, but recovery is complicated
to predict and dependent on multiple
factors.
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 depending on the degree of
interference of marine mammals
hearing. 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
(e.g., for successful mother/calf
interactions, consistent detection of
prey) 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 (Neophocaena
asiaeorientalis)) and six species of
pinnipeds (northern elephant seal
(Mirounga angustirostris), harbor seal,
ring seal, spotted seal, bearded seal, and
California sea lion (Zalophus
californianus)) that were exposed to a
limited number of sound sources (i.e.,
mostly tones and octave-band noise
with limited number of exposure to
impulsive sources such as seismic
airguns or impact pile driving) in
laboratory settings (Southall et al.,
2019a). There is currently no data
available on noise-induced hearing loss
for mysticetes. For summaries of data on
TTS or PTS in marine mammals or for
further discussion of TTS or PTS onset
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thresholds, please see Southall et al.
(2019a) and NMFS (2018).
Recent studies with captive
odontocete species (bottlenose dolphin,
harbor porpoise, beluga, and false killer
whale) have observed increases in
hearing threshold levels when
individuals received a warning sound
prior to exposure to a relatively loud
sound (Nachtigall and Supin, 2013,
2015; Nachtigall et al., 2016a–c, 2018;
Finneran, 2018). These studies suggest
that captive animals have a mechanism
to reduce hearing sensitivity prior to
impending loud sounds. Hearing change
was observed to be frequency dependent
and Finneran (2018) suggests hearing
attenuation occurs within the cochlea or
auditory nerve. Based on these
observations on captive odontocetes, the
authors suggest that wild animals may
have a mechanism to self-mitigate the
impacts of noise exposure by
dampening their hearing during
prolonged exposures of loud sound or if
conditioned to anticipate intense
sounds (Finneran, 2018; Nachtigall et
al., 2018).
Behavioral Effects
Exposure of marine mammals to
sound sources can result in, but is not
limited to, no response or any of the
following observable responses:
increased alertness; orientation or
attraction to a sound source; vocal
modifications; cessation of feeding;
cessation of social interaction; alteration
of movement or diving behavior; habitat
abandonment (temporary or permanent);
and in severe cases, panic, flight,
stampede, or stranding, potentially
resulting in death (Southall et al., 2007).
A review of marine mammal responses
to anthropogenic sound was first
conducted by Richardson (1995). More
recent reviews address studies
conducted since 1995 and focused on
observations where the received sound
level of the exposed marine mammal(s)
was known or could be estimated
(Nowacek et al., 2007; DeRuiter et al.,
2013; Ellison et al., 2012; Gomez et al.,
2016). Gomez et al. (2016) conducted a
review of the literature considering the
contextual information of exposure in
addition to received level and found
that higher received levels were not
always associated with more severe
behavioral responses and vice versa.
Southall et al. (2021) states that results
demonstrate that some individuals of
different species display clear yet varied
responses, some of which have negative
implications while others appear to
tolerate high levels and that responses
may not be fully predictable with
simple acoustic exposure metrics (e.g.,
received sound level). Rather, the
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authors state that differences among
species and individuals along with
contextual aspects of exposure (e.g.,
behavioral state) appear to affect
response probability.
Behavioral responses to sound are
highly variable and context-specific.
Many different variables can influence
an animal’s perception of and response
to (nature and magnitude) an acoustic
event. An animal’s prior experience
with a sound or sound source affects
whether it is less likely (habituation) or
more likely (sensitization) to respond to
certain sounds in the future (animals
can also be innately predisposed to
respond to certain sounds in certain
ways) (Southall et al., 2019a). Related to
the sound itself, the perceived nearness
of the sound, bearing of the sound
(approaching vs. retreating), the
similarity of a sound to biologically
relevant sounds in the animal’s
environment (i.e., calls of predators,
prey, or conspecifics), and familiarity of
the sound may affect the way an animal
responds to the sound (Southall et al.,
2007; DeRuiter et al., 2013). Individuals
(of different age, gender, reproductive
status, etc.) among most populations
will have variable hearing capabilities,
and differing behavioral sensitivities to
sounds that will be affected by prior
conditioning, experience, and current
activities of those individuals. Often,
specific acoustic features of the sound
and contextual variables (i.e., proximity,
duration, or recurrence of the sound or
the current behavior that the marine
mammal is engaged in or its prior
experience), as well as entirely separate
factors, such as the physical presence of
a nearby vessel, may be more relevant
to the animal’s response than the
received level alone.
Overall, the variability of responses to
acoustic stimuli depends on the species
receiving the sound, the sound source,
and the social, behavioral, or
environmental contexts of exposure
(e.g., DeRuiter and Doukara, 2012). For
example, Goldbogen et al. (2013a)
demonstrated that individual behavioral
state was critically important in
determining response of blue whales to
sonar, noting that some individuals
engaged in deep (greater than 50 m)
feeding behavior had greater dive
responses than those in shallow feeding
or non-feeding conditions. Some blue
whales in the Goldbogen et al. (2013a)
study that were engaged in shallow
feeding behavior demonstrated no clear
changes in diving or movement even
when received levels were high (∼160
dB re 1mPa (microPascal)) for exposures
to 3–4 kHz sonar signals, while deep
feeding and non-feeding whales showed
a clear response at exposures at lower
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received levels of sonar and
pseudorandom noise. Southall et al.
(2011) found that blue whales had a
different response to sonar exposure
depending on behavioral state, more
pronounced when deep feeding/travel
modes than when engaged in surface
feeding.
With respect to distance influencing
disturbance, DeRuiter et al. (2013)
examined behavioral responses of
Cuvier’s beaked whales to midfrequency sonar and found that whales
responded strongly at low received
levels (89–127 dB re 1mPa) by ceasing
normal fluking and echolocation,
swimming rapidly away, and extending
both dive duration and subsequent nonforaging intervals when the sound
source was 3.4–9.5 km (2.1–5.9 mi)
away. Importantly, this study also
showed that whales exposed to a similar
range of received levels (78–106 dB re
1mPa) from distant sonar exercises (118
km, or 73.3 mi, away) did not elicit such
responses, suggesting that context may
moderate reactions. Thus, distance from
the source is an important variable in
influencing the type and degree of
behavioral response and this variable is
independent of the effect of received
levels (e.g., DeRuiter et al., 2013;
Dunlop et al., 2017a–b, 2018; Falcone et
al., 2017; Southall et al., 2019a).
Ellison et al. (2012) outlined an
approach to assessing the effects of
sound on marine mammals that
incorporates contextual-based factors.
The authors recommend considering not
just the received level of sound, but also
the activity the animal is engaged in at
the time the sound is received, the
nature and novelty of the sound (i.e., is
this a new sound from the animal’s
perspective), and the distance between
the sound source and the animal. They
submit that this ‘‘exposure context,’’ as
described, greatly influences the type of
behavioral response exhibited by the
animal. Forney et al. (2017) also point
out that an apparent lack of response
(e.g., no displacement or avoidance of a
sound source) may not necessarily mean
there is no cost to the individual or
population, as some resources or
habitats may be of such high value that
animals may choose to stay, even when
experiencing stress or hearing loss.
Forney et al. (2017) recommend
considering both the costs of remaining
in an area of noise exposure such as
TTS, PTS, or masking, which could lead
to an increased risk of predation or
other threats or a decreased capability to
forage, and the costs of displacement,
including potential increased risk of
vessel strike, increased risks of
predation or competition for resources,
or decreased habitat suitable for
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foraging, resting, or socializing. This
sort of contextual information is
challenging to predict with accuracy for
ongoing activities that occur over large
spatial and temporal expanses.
However, distance is one contextual
factor for which data exist to
quantitatively inform a take estimate,
and the method for predicting Level B
harassment in this IHA does consider
distance to the source. Other factors are
often considered qualitatively in the
analysis of the likely consequences of
sound exposure where supporting
information is available.
Behavioral change, such as
disturbance manifesting in lost foraging
time, in response to anthropogenic
activities is often assumed to indicate a
biologically significant effect on a
population of concern. However,
individuals may be able to compensate
for some types and degrees of shifts in
behavior, preserving their health and
thus their vital rates and population
dynamics. For example, New et al.
(2013) developed a model simulating
the complex social, spatial, behavioral,
and motivational interactions of coastal
bottlenose dolphins in the Moray Firth,
Scotland, to assess the biological
significance of increased rate of
behavioral disruptions caused by vessel
traffic. Despite a modeled scenario in
which vessel traffic increased from 70 to
470 vessels a year (a six-fold increase in
vessel traffic) in response to the
construction of a proposed offshore
renewables facility, the dolphins’
behavioral time budget, spatial
distribution, motivations, and social
structure remained unchanged.
Similarly, two bottlenose dolphin
populations in Australia were also
modeled over 5 years against a number
of disturbances (Reed et al., 2020) and
results indicate that habitat/noise
disturbance had little overall impact on
population abundances in either
location, even in the most extreme
impact scenarios modeled. Friedlaender
et al. (2016) provided the first
integration of direct measures of prey
distribution and density variables
incorporated into across-individual
analyses of behavior responses of blue
whales to sonar and demonstrated a
five-fold increase in the ability to
quantify variability in blue whale diving
behavior. These results illustrate that
responses evaluated without such
measurements for foraging animals may
be misleading, which again illustrates
the context-dependent nature of the
probability of response.
The following subsections provide
examples of behavioral responses that
give an idea of the variability in
behavioral responses that would be
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expected given the differential
sensitivities of marine mammal species
to sound, contextual factors, and the
wide range of potential acoustic sources
to which a marine mammal may be
exposed. Behavioral responses that
could occur for a given sound exposure
should be determined from the
literature that is available for each
species, or extrapolated from closely
related species when no information
exists, along with contextual factors.
Avoidance and Displacement
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 (Eschrichtius robustus) and
humpback whales are known to change
direction—deflecting from customary
migratory paths—in order to avoid noise
from airgun surveys (Malme et al., 1984;
Dunlop et al., 2018). Avoidance is
qualitatively different from the flight
response but also differs in the
magnitude of the response (i.e., directed
movement, rate of travel, etc.).
Avoidance may be short-term with
animals returning to the area once the
noise has ceased (e.g., Malme et al.,
1984; Bowles et al., 1994; Goold, 1996;
Stone et al., 2000; Morton and
Symonds, 2002; Gailey et al., 2007;
Da¨hne et al., 2013; Russel et al., 2016).
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; Forney et
al., 2017). Avoidance of marine
mammals during the construction of
offshore wind facilities (specifically,
impact pile driving) has been
documented in the literature with some
significant variation in the temporal and
spatial degree of avoidance and with
most studies focused on harbor
porpoises as one of the most common
marine mammals in European waters
(e.g., Tougaard et al., 2009; Da¨hne et al.,
2013; Thompson et al., 2013; Russell et
al., 2016; Brandt et al., 2018).
Available information on impacts to
marine mammals from pile driving
associated with offshore wind is limited
to information on harbor porpoises and
seals, as the vast majority of this
research has occurred at European
offshore wind projects where large
whales and other odontocete species are
uncommon. Harbor porpoises and
harbor seals are considered to be
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behaviorally sensitive species (e.g.,
Southall et al., 2007) and the effects of
wind farm construction in Europe on
these species have been well
documented. These species have
received particular attention in
European waters due to their abundance
in the North Sea (Hammond et al., 2002;
Nachtsheim et al., 2021). A summary of
the literature on documented effects of
wind farm construction on harbor
porpoise and harbor seals is described
below.
Brandt et al. (2016) summarized the
effects of the construction of eight
offshore wind projects within the
German North Sea (i.e., Alpha Ventus,
BARD Offshore I, Borkum West II,
DanTysk, Global Tech I, Meerwind Su¨d/
Ost, Nordsee Ost, and Riffgat) between
2009 and 2013 on harbor porpoises,
combining passive acoustic monitoring
(PAM) data from 2010 to 2013 and aerial
surveys from 2009 to 2013 with data on
noise levels associated with pile
driving. Results of the analysis revealed
significant declines in porpoise
detections during pile driving when
compared to 25–48 hours before pile
driving began, with the magnitude of
decline during pile driving clearly
decreasing with increasing distances to
the construction site. During the
majority of projects, significant declines
in detections (by at least 20 percent)
were found within at least 5–10 km
(3.1–6.2 mi) of the pile driving site, with
declines at up to 20–30 km (12.4–18.6
mi) of the pile driving site documented
in some cases. Similar results
demonstrating the long-distance
displacement of harbor porpoises (18–
25 km; 11.1–15.5 mi) and harbor seals
(up to 40 km (24.9 mi)) during impact
pile driving have also been observed
during the construction at multiple
other European wind farms (Tougaard et
al., 2009; Bailey et al., 2010; Da¨hne et
al., 2013; Lucke et al., 2012; Haelters et
al., 2015).
While harbor porpoises and seals tend
to move several kilometers away from
wind farm construction activities, the
duration of displacement has been
documented to be relatively temporary.
In two studies at Horns Rev II using
impact pile driving, harbor porpoise
returned within 1 to 2 days following
cessation of pile driving (Tougaard et
al., 2009; Brandt et al., 2011). Similar
recovery periods have been noted for
harbor seals off England during the
construction of four wind farms
(Brasseur et al., 2012; Hamre et al.,
2011; Hastie et al., 2015; Russell et al.,
2016). In some cases, an increase in
harbor porpoise activity has been
documented inside wind farm areas
following construction (e.g., Lindeboom
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et al., 2011). Other studies have noted
longer term impacts after impact pile
driving. Near Dogger Bank in Germany,
harbor porpoises continued to avoid the
area for over 2 years after construction
began (Gilles et al., 2009).
Approximately 10 years after
construction of the Nysted wind farm,
harbor porpoise abundance had not
recovered to the original levels
previously seen, although the
echolocation activity was noted to have
been increasing when compared to the
previous monitoring period (Teilmann
and Carstensen, 2012). However,
overall, there are no indications for a
population decline of harbor porpoises
in European waters (e.g., Brandt et al.,
2016). Notably, where significant
differences in displacement and return
rates have been identified for these
species, the occurrence of secondary
project-specific influences such as use
of mitigation measures (e.g., bubble
curtains, acoustic deterrent devices), or
the manner in which species use the
habitat in the LIA, are likely the driving
factors of this variation.
NMFS notes that the aforementioned
European studies involved installing
much smaller monopiles than Vineyard
Wind proposes to install (Brandt et al.,
2016) and, therefore we anticipate noise
levels from impact pile driving to be
louder. However, we do not anticipate
any greater severity of response due to
harbor porpoise and harbor seal habitat
use off Massachusetts or populationlevel consequences similar to European
findings. In many cases, harbor
porpoises and harbor seals are resident
to the areas where European wind farms
have been constructed. However, off
Massachusetts, harbor porpoises and
seals are more transient, and a very
small percentage of the harbor seal
population are only seasonally present
with no rookeries established (Hayes et
al., 2022). In summary, we anticipate
that harbor porpoise and harbor seals
will likely respond to pile driving by
moving several kilometers away from
the source but return to typical habitat
use patterns when pile driving ceases.
Some avoidance behavior of other
marine mammal species has been
documented to be dependent on
distance from the source. As described
above, DeRuiter et al. (2013) noted that
distance from a sound source may
moderate marine mammal reactions in
their study of Cuvier’s beaked whales
(an acoustically sensitive species),
which showed the whales swimming
rapidly and silently away when a sonar
signal was 3.4–9.5 km (2.1–5.9 mi) away
while showing no such reaction to the
same signal when the signal was 118 km
(73.3 mi) away even though the received
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levels were similar. Tyack et al. (1983)
conducted playback studies of
Surveillance Towed Array Sensor
System (SURTASS) low-frequency
active (LFA) sonar in a gray whale
migratory corridor off California.
Similar to NARWs, gray whales migrate
close to shore (approximately +2 km
(+1.2 mi)) and are low-frequency
hearing specialists. The LFA sonar
source was placed within the gray
whale migratory corridor
(approximately 2 km (1.2 mi) offshore)
and offshore of most, but not all,
migrating whales (approximately 4 km
(2.5 mi) offshore). These locations
influenced received levels and distance
to the source. For the inshore playbacks,
not unexpectedly, the louder the source
level of the playback (i.e., the louder the
received level), whale avoided the
source at greater distances. Specifically,
when the source levels were 170 and
178 dB rms, whales avoided the inshore
source at ranges of several hundred
meters, similar to avoidance responses
reported by Malme et al. (1983, 1984).
Whales exposed to source levels of 185
dB rms demonstrated avoidance levels
at ranges of +1 km (+0.6 mi). Responses
to the offshore source broadcasting at
source levels of 185 and 200 dB,
avoidance responses were greatly
reduced. While there was observed
deflection from course, in no case did a
whale abandon its migratory behavior.
The signal context of the noise
exposure has been shown to play an
important role in avoidance responses.
In a 2007–2008 Bahamas study,
playback sounds of a potential
predator—a killer whale—resulted in a
similar but more pronounced reaction in
beaked whales (an acoustically sensitive
species), which included longer interdive intervals and a sustained straightline departure of more than 20 km (12.4
mi) from the area (Boyd et al., 2008;
Southall et al., 2009; Tyack et al., 2011).
In contrast, the sounds produced by pile
driving activities do not have signal
characteristics similar to predators.
Therefore, we would not expect such
extreme reactions to occur. Southall et
al. (2011) found that blue whales had a
different response to sonar exposure
depending on behavioral state, more
pronounced when deep feeding/travel
modes than when engaged in surface
feeding.
One potential consequence of
behavioral avoidance is the altered
energetic expenditure of marine
mammals because energy is required to
move and avoid surface vessels or the
sound field associated with active sonar
(Frid and Dill, 2002). Most animals can
avoid that energetic cost by swimming
away at slow speeds or speeds that
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minimize the cost of transport (MiksisOlds, 2006), as has been demonstrated
in Florida manatees (Miksis-Olds, 2006).
Those energetic costs increase, however,
when animals shift from a resting state,
which is designed to conserve an
animal’s energy, to an active state that
consumes energy the animal would
have conserved had it not been
disturbed. Marine mammals that have
been disturbed by anthropogenic noise
and vessel approaches are commonly
reported to shift from resting to active
behavioral states, which would imply
that they incur an energy cost.
Forney et al. (2017) detailed the
potential effects of noise on marine
mammal populations with high site
fidelity, including displacement and
auditory masking, noting that a lack of
observed response does not imply
absence of fitness costs and that
apparent tolerance of disturbance may
have population-level impacts that are
less obvious and difficult to document.
Avoidance of overlap between
disturbing noise and areas and/or times
of particular importance for sensitive
species may be critical to avoiding
population-level impacts because
(particularly for animals with high site
fidelity) there may be a strong
motivation to remain in the area despite
negative impacts. Forney et al. (2017)
stated that, for these animals, remaining
in a disturbed area may reflect a lack of
alternatives rather than a lack of effects.
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,
rate of travel). Relatively little
information on flight responses of
marine mammals to anthropogenic
signals exist, but observations of flight
responses to the presence of predators
have occurred (Connor and Heithaus,
1996; Frid and Dill, 2002). 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, beaked whale
strandings (Cox et al., 2006; D’Amico et
al., 2009). 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. Flight
responses of marine mammals have
been documented in response to mobile
high intensity active sonar (e.g., Tyack
et al., 2011; DeRuiter et al., 2013;
Wensveen et al., 2019), and more severe
responses have been documented when
sources are moving towards an animal
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or when they are surprised by
unpredictable exposures (Watkins,
1986; Falcone et al., 2017). Generally
speaking, however, marine mammals
would be expected to be less likely to
respond with a flight response to
stationery pile driving (which they can
sense is stationery and predictable),
unless they are within the area
ensonified above behavioral harassment
thresholds at the moment the pile
driving begins (Watkins, 1986; Falcone
et al., 2017).
Diving and Foraging
Changes in dive behavior in response
to noise exposure can vary widely. They
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; Goldbogen et
al., 2013b). Variations in dive behavior
may reflect interruptions in biologically
significant activities (e.g., foraging) or
they may be of little biological
significance. Variations in dive behavior
may also expose an animal to
potentially harmful conditions (e.g.,
increasing the chance of ship-strike) or
may serve as an avoidance response that
enhances survivorship. The impact of a
variation in diving resulting from an
acoustic exposure depends on what the
animal is doing at the time of the
exposure, the type and magnitude of the
response, and the context within which
the response occurs (e.g., the
surrounding environmental and
anthropogenic circumstances).
Nowacek et al. (2004) reported
disruptions of dive behaviors in foraging
NARWs when exposed to an alerting
stimulus, an action, they noted, that
could lead to an increased likelihood of
ship strike. The alerting stimulus was in
the form of an 18-minute exposure that
included three 2-minute signals played
three times sequentially. This stimulus
was designed with the purpose of
providing signals distinct to background
noise that serve as localization cues.
However, the whales did not respond to
playbacks of either right whale social
sounds or vessel noise, highlighting the
importance of the sound characteristics
in producing a behavioral reaction.
Although source levels for the proposed
pile driving activities may exceed the
received level of the alerting stimulus
described by Nowacek et al. (2004),
proposed mitigation strategies (further
described in the Proposed Mitigation
section) will reduce the severity of
response to proposed pile driving
activities. Converse to the behavior of
NARWs, Indo-Pacific humpback
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dolphins have been observed to dive for
longer periods of time in areas where
vessels were present and/or
approaching (Ng and Leung, 2003). In
both of these studies, the influence of
the sound exposure cannot be
decoupled from the physical presence of
a surface vessel, thus complicating
interpretations of the relative
contribution of each stimulus to the
response. Indeed, the presence of
surface vessels, their approach, and
speed of approach, seemed to be
significant factors in the response of the
Indo-Pacific humpback dolphins (Ng
and Leung, 2003). Low-frequency
signals of the Acoustic Thermometry of
Ocean Climate (ATOC) sound source
were not found to affect dive times of
humpback whales in Hawaiian waters
(Frankel and Clark, 2000) or to overtly
affect elephant seal dives (Costa et al.,
2003). They did, however, produce
subtle effects that varied in direction
and degree among the individual seals,
illustrating the equivocal nature of
behavioral effects and consequent
difficulty in defining and predicting
them.
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 cessation of
secondary indicators of foraging (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; Southall et al., 2019b). An
understanding 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
can facilitate the assessment of whether
foraging disruptions are likely to incur
fitness consequences (Goldbogen et al.,
2013b; Farmer et al., 2018; Pirotta et al.,
2018a; Southall et al., 2019a; Pirotta et
al., 2021).
Impacts on marine mammal foraging
rates from noise exposure have been
documented, though there is little data
regarding the impacts of offshore
turbine construction specifically.
Several broader examples follow, and it
is reasonable to expect that exposure to
noise produced during the year that the
proposed IHA would be effective could
have similar impacts. Visual tracking,
passive acoustic monitoring, and
movement recording tags were used to
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quantify sperm whale behavior prior to,
during, and following exposure to
airgun arrays at received levels in the
range 140–160 dB at distances of 7–13
km (4.3–8.1 mi), following a phase-in of
sound intensity and full array exposures
at 1–13 km (0.6–8.1 mi) (Madsen et al.,
2006; Miller et al., 2009). Sperm whales
did not exhibit horizontal avoidance
behavior at the surface. However,
foraging behavior may have been
affected. The sperm whales exhibited 19
percent less vocal (buzz) rate during full
exposure relative to post exposure, and
the whale that was approached most
closely had an extended resting period
and did not resume foraging until the
airguns had ceased firing. The
remaining whales continued to execute
foraging dives throughout exposure;
however, swimming movements during
foraging dives were 6 percent lower
during exposure than during control
periods (Miller et al., 2009). Miller et al.
(2009) noted that more data are required
to understand whether the differences
were due to exposure or natural
variation in sperm whale behavior.
Balaenopterid whales exposed to
moderate low-frequency signals similar
to the ATOC sound source
demonstrated no variation in foraging
activity (Croll et al., 2001), whereas five
out of six NARWs exposed to an
acoustic alarm interrupted their foraging
dives (Nowacek et al., 2004). Although
the received SPLs were similar in the
latter two studies, the frequency,
duration, and temporal pattern of signal
presentation were different. These
factors, as well as differences in species
sensitivity, are likely contributing
factors to the differential response. The
noise generated by Vineyard Wind’s
proposed activities would at least
partially overlap in frequency with
signals described by Nowacek et al.
(2004) and Croll et al. (2001). Blue
whales exposed to mid-frequency sonar
in the Southern California Bight were
less likely to produce low-frequency
calls usually associated with feeding
behavior (Melco´n et al., 2012). However,
Melco´n et al. (2012) were unable to
determine if suppression of lowfrequency calls reflected a change in
their feeding performance or
abandonment of foraging behavior and
indicated that implications of the
documented responses are unknown.
Further, it is not known whether the
lower rates of calling actually indicated
a reduction in feeding behavior or social
contact since the study used data from
remotely deployed, passive acoustic
monitoring buoys. Results from the
2010–2011 field season of a behavioral
response study of tagged blue whales in
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Southern California waters indicated
that, in some cases and at low received
levels, the whales responded to midfrequency sonar but that those responses
were mild and there was a quick return
to their baseline activity (Southall et al.,
2011, 2012b, 2019).
Information on or estimates of the
energetic requirements of the
individuals and the relationship
between prey availability, foraging effort
and success, and the life history stage of
the animal will help better inform a
determination of whether foraging
disruptions incur fitness consequences.
Foraging strategies may impact foraging
efficiency, such as by reducing foraging
effort and increasing success in prey
detection and capture, in turn
promoting fitness and allowing
individuals to better compensate for
foraging disruptions. Surface feeding
blue whales did not show a change in
behavior in response to mid-frequency
simulated and real sonar sources with
received levels between 90 and 179 dB
re 1 mPa, but deep feeding and nonfeeding whales showed temporary
reactions including cessation of feeding,
reduced initiation of deep foraging
dives, generalized avoidance responses,
and changes to dive behavior (DeRuiter
et al., 2017; Goldbogen et al., 2013b;
Sivle et al., 2015). Goldbogen et al.
(2013b) indicate that disruption of
feeding and displacement could impact
individual fitness and health. However,
for this to be true, we would have to
assume that an individual whale could
not compensate for this lost feeding
opportunity by either immediately
feeding at another location, by feeding
shortly after cessation of acoustic
exposure, or by feeding at a later time.
There is no indication that individual
fitness and health would be impacted by
an activity that influences foraging
disruption, particularly since
unconsumed prey would likely still be
available in the environment in most
cases following the cessation of acoustic
exposure.
Similarly, while the rates of foraging
lunges decrease in humpback whales
due to sonar exposure, there was
variability in the response across
individuals, with one animal ceasing to
forage completely and another animal
starting to forage during the exposure
(Sivle et al., 2016). In addition, almost
half of the animals that demonstrated
avoidance were foraging before the
exposure, but the others were not; the
animals that avoided while not feeding
responded at a slightly lower received
level and greater distance than those
that were feeding (Wensveen et al.,
2017). These findings indicate the
behavioral state of the animal and
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foraging strategies play a role in the type
and severity of a behavioral response.
For example, when the prey field was
mapped and used as a covariate in
examining how behavioral state of blue
whales is influenced by mid-frequency
sound, the response in blue whale deepfeeding behavior was even more
apparent, reinforcing the need for
contextual variables to be included
when assessing behavioral responses
(Friedlaender et al., 2016).
Vocalizations and Auditory Masking
Marine mammals vocalize for
different purposes and across multiple
modes, such as whistling, production of
echolocation clicks, calling, and singing.
Changes in vocalization behavior in
response to anthropogenic noise can
occur for any of these modes and may
result directly from increased vigilance
or a startle response, or from a need to
compete with an increase in background
noise (see Erbe et al., 2016 review on
communication masking), the latter of
which is described more below.
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) and blue
whales increased song production (Di
Iorio and Clark, 2009), while NARWs
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 or reduce sound
production during production of
aversive signals (Bowles et al., 1994;
Thode et al., 2020; Cerchio et al., 2014;
McDonald et al., 1995). Blackwell et al.
(2015) showed that whales increased
calling rates as soon as airgun signals
were detectable before ultimately
decreasing calling rates at higher
received levels.
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, or
navigation) (Richardson et al., 1995;
Erbe and Farmer, 2000; Tyack, 2000;
Erbe et al., 2016; Sorensen et al., 2023).
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
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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.
Masking these acoustic signals can
disturb the behavior of individual
animals, groups of animals, or entire
populations. Masking can lead to
behavioral changes including vocal
changes (e.g., Lombard effect, increasing
amplitude, or changing frequency),
cessation of foraging or lost foraging
opportunities, and leaving an area, to
both signalers and receivers, in an
attempt to compensate for noise levels
(Erbe et al., 2016) or because sounds
that would typically have triggered a
behavior were not detected. Even when
animals attempt to compensate for
masking, such as by increasing the
amplitude or duration of their signals,
this may still be insufficient to maintain
behavioral coordination between
individuals necessary for complex
behaviors, foraging, and navigation
(Sorensen et al., 2023). In humans,
significant masking of tonal signals
occurs as a result of exposure to noise
in a narrow band of similar frequencies.
As the sound level increases, the
detection of frequencies above those of
the masking stimulus decreases. This
principle is expected to apply to marine
mammals as well because of common
biomechanical cochlear properties
across taxa.
Therefore, when the coincident
(masking) sound is man-made, it may be
considered harassment when disrupting
behavioral patterns. It is important to
distinguish TTS and PTS, which persist
after the sound exposure, from masking,
which only occurs during the sound
exposure. Because masking (without
resulting in threshold shift) 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 highfrequency 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
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communication signals by
anthropogenic noise may be considered
as a reduction in the communication
space of animals (e.g., Clark et al., 2009;
Matthews, 2017) 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; Cholewiak et al.,
2018).
The echolocation calls of toothed
whales are subject to masking by highfrequency sound. Human data indicate
low-frequency sound can mask highfrequency sounds (i.e., upward
masking). Studies on captive
odontocetes by Au et al. (1974, 1985,
1993) indicate that some species may
use various processes to reduce masking
effects (e.g., adjustments in echolocation
call intensity or frequency as a function
of background noise conditions). There
is also evidence that the directional
hearing abilities of odontocetes are
useful in reducing masking at the highfrequencies these cetaceans use to
echolocate, but not at the low-tomoderate frequencies they use to
communicate (Zaitseva et al., 1980). A
study by Nachtigall and Supin (2008)
showed that false killer whales adjust
their hearing to compensate for ambient
sounds and the intensity of returning
echolocation signals.
Impacts on signal detection, measured
by masked detection thresholds, are not
the only important factors to address
when considering the potential effects
of masking. As marine mammals use
sound to recognize conspecifics, prey,
predators, or other biologically
significant sources (Branstetter et al.,
2016), it is also important to understand
the impacts of masked recognition
thresholds (often called ‘‘informational
masking’’). Branstetter et al. (2016)
measured masked recognition
thresholds for whistle-like sounds of
bottlenose dolphins and observed that
they are approximately 4 dB above
detection thresholds (energetic masking)
for the same signals. Reduced ability to
recognize a conspecific call or the
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acoustic signature of a predator could
have severe negative impacts.
Branstetter et al. (2016) observed that if
‘‘quality communication’’ is set at 90
percent recognition the output of
communication space models (which
are based on 50 percent detection)
would likely result in a significant
decrease in communication range.
As marine mammals use sound to
recognize predators (Allen et al., 2014;
Cummings and Thompson, 1971; Cure´
et al., 2015; Fish and Vania, 1971), the
presence of masking noise may also
prevent marine mammals from
responding to acoustic cues produced
by their predators, particularly if it
occurs in the same frequency band. For
example, harbor seals that reside in the
coastal waters off British Columbia are
frequently targeted by mammal-eating
killer whales. The seals acoustically
discriminate between the calls of
mammal-eating and fish-eating killer
whales (Deecke et al., 2002), a capability
that should increase survivorship while
reducing the energy required to attend
to all killer whale calls. Similarly,
sperm whales (Cure´ et al., 2016;
Isojunno et al., 2016), long-finned pilot
whales (Visser et al., 2016), and
humpback whales (Cure´ et al., 2015)
changed their behavior in response to
killer whale vocalization playbacks;
these findings indicate that some
recognition of predator cues could be
missed if the killer whale vocalizations
were masked. The potential effects of
masked predator acoustic cues depend
on the duration of the masking noise
and the likelihood of a marine mammal
encountering a predator during the time
that detection and recognition of
predator cues are impeded.
Redundancy and context can also
facilitate detection of weak signals.
These phenomena may help marine
mammals detect weak sounds in the
presence of natural or manmade noise.
Most masking studies in marine
mammals present the test signal and the
masking noise from the same direction.
The dominant background noise may be
highly directional if it comes from a
particular anthropogenic source such as
a ship or industrial site. Directional
hearing may significantly reduce the
masking effects of these sounds by
improving the effective signal-to-noise
ratio.
Masking affects both senders and
receivers of acoustic signals and, at
higher levels and longer duration, 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
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in terms of sound pressure level (SPL))
in the world’s ocean from pre-industrial
periods, with most of the increase from
distant commercial shipping
(Hildebrand, 2009; Cholewiak et al.,
2018). All anthropogenic sound sources,
but especially chronic and lowerfrequency signals (e.g., from commercial
vessel traffic), contribute to elevated
ambient sound levels, thus intensifying
masking.
In addition to making it more difficult
for animals to perceive and recognize
acoustic cues in their environment,
anthropogenic sound presents separate
challenges for animals that are
vocalizing. When they vocalize, animals
are aware of environmental conditions
that affect the ‘‘active space’’ (or
communication space) of their
vocalizations, which is the maximum
area within which their vocalizations
can be detected before it drops to the
level of ambient noise (Brenowitz, 2004;
Brumm et al., 2004; Lohr et al., 2003).
Animals are also aware of
environmental conditions that affect
whether listeners can discriminate and
recognize their vocalizations from other
sounds, which is more important than
simply detecting that a vocalization is
occurring (Brenowitz, 1982; Brumm et
al., 2004; Dooling, 2004; Marten and
Marler, 1977; Patricelli and Blickley,
2006). Most species that vocalize have
evolved with an ability to adjust their
vocalizations to increase the signal-tonoise ratio, active space, and
recognizability/distinguishability of
their vocalizations in the face of
temporary changes in background noise
(Brumm et al., 2004; Patricelli and
Blickley, 2006). Vocalizing animals can
adjust their vocalization characteristics
such as the frequency structure,
amplitude, temporal structure, and
temporal delivery (repetition rate), or
ceasing to vocalize.
Many animals will combine several of
these strategies to compensate for high
levels of background noise.
Anthropogenic sounds that reduce the
signal-to-noise ratio of animal
vocalizations; increase the masked
auditory thresholds of animals listening
for such vocalizations; or reduce the
active space of an animal’s vocalizations
impair communication between
animals. Most animals that vocalize
have evolved strategies to compensate
for the effects of short-term or temporary
increases in background or ambient
noise on their songs or calls. Although
the fitness consequences of these vocal
adjustments are not directly known in
all instances, like most other trade-offs
animals must make, some of these
strategies likely come at a cost (Patricelli
and Blickley, 2006; Noren et al., 2017;
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Noren et al., 2020). Shifting songs and
calls to higher frequencies may also
impose energetic costs (Lambrechts,
1996).
Marine mammals are also known to
make vocal changes in response to
anthropogenic noise. In cetaceans,
vocalization changes have been reported
from exposure to anthropogenic noise
sources such as sonar, vessel noise, and
seismic surveying (e.g., Gordon et al.,
2003; Di Iorio and Clark, 2009; Hatch et
al., 2012; Holt et al., 2009, 2011; Lesage
et al., 1999; McDonald et al., 2009;
Parks et al., 2007; Risch et al., 2012;
Rolland et al., 2012), as well as changes
in the natural acoustic environment
(Dunlop et al., 2014). Vocal changes can
be temporary or can be persistent. For
example, model simulation suggests that
the increase in starting frequency for the
NARW upcall over the last 50 years
resulted in increased detection ranges
between right whales. The frequency
shift, coupled with an increase in call
intensity by 20 dB, led to a call
detectability range of less than 3 km (1.9
mi) to over 9 km (5.6 mi) (Tennessen
and Parks, 2016). Holt et al. (2009)
measured killer whale call source levels
and background noise levels in the 1 to
40 kHz band and reported that the
whales increased their call source levels
by 1-dB SPL for every 1-dB SPL increase
in background noise level. Similarly,
another study on St. Lawrence River
belugas reported a similar rate of
increase in vocalization activity in
response to passing vessels (Scheifele et
al., 2005). Di Iorio and Clark (2009)
showed that blue whale calling rates
vary in association with seismic sparker
survey activity, with whales calling
more on days with surveys than on days
without surveys. They suggested that
the whales called more during seismic
survey periods as a way to compensate
for the elevated noise conditions.
In some cases, these vocal changes
may have fitness consequences, such as
an increase in metabolic rates and
oxygen consumption, as observed in
bottlenose dolphins when increasing
their call amplitude (Holt et al., 2015).
A switch from vocal communication to
physical, surface-generated sounds such
as pectoral fin slapping or breaching
was observed for humpback whales in
the presence of increasing natural
background noise levels, indicating that
adaptations to masking may also move
beyond vocal modifications (Dunlop et
al., 2010).
While these changes all represent
possible tactics by the sound-producing
animal to reduce the impact of masking,
the receiving animal can also reduce
masking by using active listening
strategies such as orienting to the sound
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source, moving to a quieter location, or
reducing self-noise from hydrodynamic
flow by remaining still. The temporal
structure of noise (e.g., amplitude
modulation) may also provide a
considerable release from masking
through comodulation masking release
(a reduction of masking that occurs
when broadband noise, with a
frequency spectrum wider than an
animal’s auditory filter bandwidth at the
frequency of interest, is amplitude
modulated) (Branstetter and Finneran,
2008; Branstetter et al., 2013). Signal
type (e.g., whistles, burst-pulse, sonar
clicks) and spectral characteristics (e.g.,
frequency modulated with harmonics)
may further influence masked detection
thresholds (Branstetter et al., 2016;
Cunningham et al., 2014).
Masking is more likely to occur in the
presence of broadband, relatively
continuous noise sources, such as
vessels. Several studies have shown
decreases in marine mammal
communication space and changes in
behavior as a result of the presence of
vessel noise. For example, right whales
were 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) as well as increasing the
amplitude (intensity) of their calls
(Parks, 2009, 2011). Clark et al. (2009)
observed that right whales’
communication space decreased by up
to 84 percent in the presence of vessels
due to an increase in ambient noise
from vessels in proximity to the whales.
Cholewiak et al. (2018) also observed
loss in communication space in
Stellwagen National Marine Sanctuary
for NARWs, fin whales, and humpback
whales with increased ambient noise
and shipping noise. Although
humpback whales off Australia did not
change the frequency or duration of
their vocalizations in the presence of
ship noise, their source levels were
lower than expected based on source
level changes to wind noise, potentially
indicating some signal masking
(Dunlop, 2016). Multiple delphinid
species have also been shown to
increase the minimum or maximum
frequencies of their whistles in the
presence of anthropogenic noise and
reduced communication space (e.g.,
Holt et al., 2009, 2011; Gervaise et al.,
2012; Williams et al., 2013; Hermannsen
et al., 2014; Papale et al., 2015; Liu et
al., 2017). While masking impacts are
not a concern from lower intensity,
higher frequency HRG surveys, some
degree of masking would be expected in
the vicinity of turbine pile driving and
concentrated support vessel operation.
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However, pile driving is an intermittent
sound and would not be continuous
throughout the day.
Habituation and Sensitization
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). Habituation is
considered 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 having a
neutral or positive outcome (Bejder et
al., 2009). Animals are most likely to
habituate to sounds that are predictable
and unvarying. 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.
Both habituation and sensitization
require an ongoing learning process. 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; National Research Council (NRC),
2003; Wartzok et al., 2003; Southall et
al., 2019b). Controlled experiments with
captive marine mammals have shown
pronounced behavioral reactions,
including avoidance of loud sound
sources (e.g., Ridgway et al., 1997;
Finneran et al., 2003; Houser et al.,
2013a–b; Kastelein et al., 2018).
Observed responses of wild marine
mammals to loud impulsive 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;
Richardson et al., 1995; Nowacek et al.,
2007; Tougaard et al., 2009; Brandt et
al., 2011, 2012, 2014, 2018; Da¨hne et al.,
2013; Russell et al., 2016).
Stone (2015) reported data from at-sea
observations during 1,196 airgun
surveys from 1994 to 2010. When large
arrays of airguns (considered to be 500
cubic inches (in3) or more) were firing,
lateral displacement, more localized
avoidance, or other changes in behavior
were evident for most odontocetes.
However, significant responses to large
arrays were found only for the minke
whale and fin whale. Behavioral
responses observed included changes in
swimming or surfacing behavior with
indications that cetaceans remained
near the water surface at these times.
Behavioral observations of gray whales
during an airgun survey monitored
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whale movements and respirations
before, during, and after seismic surveys
(Gailey et al., 2016). Behavioral state
and water depth were the best ‘‘natural’’
predictors of whale movements and
respiration, and after accounting for
natural variation, none of the response
variables were significantly associated
with survey or vessel sounds. 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.
Physiological 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., Selye, 1950; Moberg and
Mench, 2000). In many cases, an
animal’s first, and sometimes most
economical response (in terms of
energetic costs) 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-pituitaryadrenal system. Virtually all
neuroendocrine functions that are
affected by stress—including immune
competence, reproduction, metabolism,
and behavior—are regulated by pituitary
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
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energetic reserves sufficiently 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 specifically in
wild populations (e.g., Lusseau and
Bejder, 2007; Romano et al., 2002a;
Rolland et al., 2012). 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 NARWs.
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, 2017). Respiration naturally
varies with different behaviors, and
variations in respiration 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.
Mean exhalation rates of gray whales at
rest and while diving were found to be
unaffected by seismic surveys
conducted adjacent to the whale feeding
grounds (Gailey et al., 2007). Studies
with captive harbor porpoises show
increased respiration rates upon
introduction of acoustic alarms
(Kastelein et al., 2001, 2006a) and
emissions for underwater data
transmission (Kastelein et al., 2005).
However, exposure of the same acoustic
alarm to a striped dolphin under the
same conditions did not elicit a
response (Kastelein et al., 2006a), 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.
Stranding
The definition for a stranding under
the MMPA is that: (A) a marine mammal
is dead and is (i) on a beach or shore
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of the United States, or (ii) in waters
under the jurisdiction of the United
States (including any navigable waters);
or (B) a marine mammal is alive and is
(i) on a beach or shore of the United
States and is unable to return to the
water, (ii) on a beach or shore of the
United States and, although able to
return to the water, is in need of
apparent medical attention, or (iii) in
the waters under the jurisdiction of the
United States (including any navigable
waters), but is unable to return to its
natural habitat under its own power or
without assistance (16 U.S.C. 1421h).
Marine mammal strandings have been
linked to a variety of causes, such as
illness from exposure to infectious
agents, biotoxins, or parasites;
starvation; unusual oceanographic or
weather events; or anthropogenic causes
including fishery interaction, ship
strike, entrainment, entrapment, sound
exposure, or combinations of these
stressors sustained concurrently or in
series. There have been multiple events
worldwide in which marine mammals
(primarily beaked whales, or other deep
divers) have stranded coincident with
relatively nearby activities utilizing
loud sound sources (primarily military
training events), and five in which midfrequency active sonar has been more
definitively determined to have been a
contributing factor.
There are multiple theories regarding
the specific mechanisms responsible for
marine mammal strandings caused by
exposure to loud sounds. One primary
theme is the behaviorally mediated
responses of deep-diving species
(odontocetes), in which their startled
response to an acoustic disturbance: (1)
affects ascent or descent rates, the time
they stay at depth or the surface, or
other regular dive patterns that are used
to physiologically manage gas formation
and absorption within their bodies, such
that the formation or growth of gas
bubbles damages tissues or causes other
injury; or (2) results in their flight to
shallow areas, enclosed bays, or other
areas considered ‘‘out of habitat,’’ in
which they become disoriented and
physiologically compromised. For more
information on marine mammal
stranding events and potential causes,
please see the Stranding and Mortality
discussion in NMFS’ proposed rule for
the Navy’s Training and Testing
Activities in the Hawaii-Southern
California Training and Testing Study
Area (83 FR 29872, 29928; June 26,
2018).
The construction activities proposed
by Vineyard Wind (i.e., pile driving) are
not expected to result in marine
mammal strandings. Of the strandings
documented to date worldwide, NMFS
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disturbance and respond accordingly,
which includes scanning for the source
of the stimulus or ‘‘vigilance’’
(Cowlishaw et al., 2004).
Vigilance is an adaptive behavior that
helps animals determine the presence or
absence of predators, assess their
distance from conspecifics, or to attend
cues from prey (Bednekoff and Lima,
1998; Treves, 2000). Despite those
benefits, however, vigilance has a cost
of time; when animals focus their
attention on specific environmental
Potential Effects of Disturbance on
cues, they are not attending to other
Marine Mammal Fitness
activities such as foraging or resting.
The different ways that marine
These effects have generally not been
mammals respond to sound are
demonstrated for marine mammals, but
sometimes indicators of the ultimate
studies involving fish and terrestrial
effect that exposure to a given stimulus
animals have shown that increased
will have on the well-being (survival,
vigilance may substantially reduce
reproduction, etc.) of an animal. There
feeding rates (Saino, 1994; Beauchamp
are numerous data relating the exposure and Livoreil, 1997; Fritz et al., 2002;
of terrestrial mammals from sound to
Purser and Radford, 2011). Animals will
effects on reproduction or survival, and
spend more time being vigilant, which
data for marine mammals continues to
may translate to less time foraging or
grow. Several authors have reported that resting, when disturbance stimuli
disturbance stimuli may cause animals
approach them more directly, remain at
to abandon nesting and foraging sites
closer distances, have a greater group
(Sutherland and Crockford, 1993); may
size (e.g., multiple surface vessels), or
cause animals to increase their activity
when they co-occur with times that an
levels and suffer premature deaths or
animal perceives increased risk (e.g.,
reduced reproductive success when
when they are giving birth or
their energy expenditures exceed their
accompanied by a calf).
energy budgets (Daan et al., 1996; Feare,
The primary mechanism by which
1976; Mullner et al., 2004); or may cause increased vigilance and disturbance
animals to experience higher predation
appear to affect the fitness of individual
rates when they adopt risk-prone
animals is by disrupting an animal’s
foraging or migratory strategies (Frid
time budget and, as a result, reducing
and Dill, 2002). Each of these studies
the time they might spend foraging and
addressed the consequences of animals
resting (which increases an animal’s
shifting from one behavioral state (e.g.,
activity rate and energy demand while
resting or foraging) to another
decreasing their caloric intake/energy).
behavioral state (e.g., avoidance or
In a study of northern resident killer
escape behavior) because of human
whales off Vancouver Island, exposure
disturbance or disturbance stimuli.
to boat traffic was shown to reduce
Attention is the cognitive process of
foraging opportunities and increase
selectively concentrating on one aspect
traveling time (Holt et al., 2021). A
of an animal’s environment while
simple bioenergetics model was applied
ignoring other things (Posner, 1994).
to show that the reduced foraging
Because animals (including humans)
opportunities equated to a decreased
have limited cognitive resources, there
energy intake of 18 percent while the
is a limit to how much sensory
increased traveling incurred an
information they can process at any
increased energy output of 3–4 percent,
time. The phenomenon called
which suggests that a management
‘‘attentional capture’’ occurs when a
action based on avoiding interference
stimulus (usually a stimulus that an
with foraging might be particularly
animal is not concentrating on or
effective.
attending to) ‘‘captures’’ an animal’s
On a related note, many animals
attention. This shift in attention can
perform vital functions, such as feeding,
resting, traveling, and socializing, on a
occur consciously or subconsciously
diel cycle (24-hour cycle). Behavioral
(for example, when an animal hears
reactions to noise exposure (such as
sounds that it associates with the
disruption of critical life functions,
approach of a predator) and the shift in
displacement, or avoidance of important
attention can be sudden (Dukas, 2002;
habitat) are more likely to be significant
van Rij, 2007). Once a stimulus has
for fitness if they last more than one diel
captured an animal’s attention, the
cycle or recur on subsequent days
animal can respond by ignoring the
(Southall et al., 2007). Consequently, a
stimulus, assuming a ‘‘watch and wait’’
behavioral response lasting less than 1
posture, or treat the stimulus as a
is not aware of any being attributed to
pile driving. While vessel strikes could
kill or injure a marine mammal (which
may then eventually strand), the
required mitigation measures would
reduce the potential for take from these
activities to de minimis levels (see
Proposed Mitigation section for more
details). As described above, no
mortality or serious injury is anticipated
or proposed to be authorized from any
Project activities.
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day and not recurring on subsequent
days is not considered particularly
severe unless it could directly affect
reproduction or survival (Southall et al.,
2007). It is important to note the
difference between behavioral reactions
lasting or recurring over multiple days
and anthropogenic activities lasting or
recurring over multiple days. For
example, just because certain activities
last for multiple days does not
necessarily mean that individual
animals will be either exposed to those
activity-related stressors (i.e., sonar) for
multiple days or further exposed in a
manner that would result in sustained
multi-day substantive behavioral
responses. However, special attention is
warranted where longer-duration
activities overlay areas in which
animals are known to congregate for
longer durations for biologically
important behaviors.
There are few studies that directly
illustrate the impacts of disturbance on
marine mammal populations. Lusseau
and Bejder (2007) present data from
three long-term studies illustrating the
connections between disturbance from
whale-watching boats and populationlevel effects in cetaceans. In Shark Bay,
Australia, the abundance of bottlenose
dolphins was compared within adjacent
control and tourism sites over three
consecutive 4.5-year periods of
increasing tourism levels. Between the
second and third time periods, in which
tourism doubled, dolphin abundance
decreased by 15 percent in the tourism
area and did not change significantly in
the control area. In Fiordland, New
Zealand, two populations (Milford and
Doubtful Sounds) of bottlenose dolphins
with tourism levels that differed by a
factor of seven were observed and
significant increases in traveling time
and decreases in resting time were
documented for both. Consistent shortterm avoidance strategies were observed
in response to tour boats until a
threshold of disturbance was reached
(average of 68 minutes between
interactions), after which the response
switched to a longer-term habitat
displacement strategy. For one
population, tourism only occurred in a
part of the home range. However,
tourism occurred throughout the home
range of the Doubtful Sound population
and once boat traffic increased beyond
the 68-minute threshold (resulting in
abandonment of their home range/
preferred habitat), reproductive success
drastically decreased (increased
stillbirths) and abundance decreased
significantly (from 67 to 56 individuals
in a short period).
In order to understand how the effects
of activities may or may not impact
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species and stocks of marine mammals,
it is necessary to understand not only
what the likely disturbances are going to
be but how those disturbances may
affect the reproductive success and
survivorship of individuals, and then
how those impacts to individuals
translate to population-level effects.
Following on the earlier work of a
committee of the U.S. NRC (NRC, 2005),
New et al. (2014), in an effort termed the
Potential Consequences of Disturbance
(PCoD), outlined an updated conceptual
model of the relationships linking
disturbance to changes in behavior and
physiology, health, vital rates, and
population dynamics. This framework is
a four-step process progressing from
changes in individual behavior and/or
physiology, to changes in individual
health, then vital rates, and finally to
population-level effects. In this
framework, behavioral and
physiological changes can have direct
(acute) effects on vital rates, such as
when changes in habitat use or
increased stress levels raise the
probability of mother-calf separation or
predation; indirect and long-term
(chronic) effects on vital rates, such as
when changes in time/energy budgets or
increased disease susceptibility affect
health, which then affects vital rates; or
no effect to vital rates (New et al., 2014).
Since the PCoD general framework
was outlined and the relevant
supporting literature compiled, multiple
studies developing state-space energetic
models for species with extensive longterm monitoring (e.g., southern elephant
seals, NARWs, Ziphiidae beaked
whales, and bottlenose dolphins) have
been conducted and can be used to
effectively forecast longer-term,
population-level impacts from
behavioral changes. While these are
very specific models with very specific
data requirements that cannot yet be
applied broadly to project-specific risk
assessments for the majority of species,
they are a critical first step towards
being able to quantify the likelihood of
a population level effect. Since New et
al. (2014), several publications have
described models developed to examine
the long-term effects of environmental
or anthropogenic disturbance of foraging
on various life stages of selected species
(e.g., sperm whale, Farmer et al., 2018;
California sea lion, McHuron et al.,
2018; blue whale, Pirotta et al., 2018a;
humpback whale, Dunlop et al., 2021).
These models continue to add to
refinement of the approaches to the
PCoD framework. Such models also
help identify what data inputs require
further investigation. Pirotta et al.
(2018b) provides a review of the PCoD
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framework with details on each step of
the process and approaches to applying
real data or simulations to achieve each
step.
Despite its simplicity, there are few
complete PCoD models available for any
marine mammal species due to a lack of
data available to parameterize many of
the steps. To date, no PCoD model has
been fully parameterized with empirical
data (Pirotta et al., 2018a) due to the fact
they are data intensive and logistically
challenging to complete. Therefore,
most complete PCoD models include
simulations, theoretical modeling, and
expert opinion to move through the
steps. For example, PCoD models have
been developed to evaluate the effect of
wind farm construction on the North
Sea harbor porpoise populations (e.g.,
King et al., 2015; Nabe-Nielsen et al.,
2018). These models include a mix of
empirical data, expert elicitation (King
et al., 2015) and simulations of animals’
movements, energetics, and/or survival
(New et al., 2014; Nabe-Nielsen et al.,
2018).
PCoD models may also be approached
in different manners. Dunlop et al.
(2021) modeled migrating humpback
whale mother-calf pairs in response to
seismic surveys using both a forwards
and backwards approach. While a
typical forwards approach can
determine if a stressor would have
population-level consequences, Dunlop
et al. demonstrated that working
backwards through a PCoD model can
be used to assess the most unfavorable
scenario for an interaction of a target
species and stressor. This method may
be useful for future management goals
when appropriate data becomes
available to fully support the model. In
another example, harbor porpoise PCoD
model investigating the impact of
seismic surveys on harbor porpoise
included an investigation on underlying
drivers of vulnerability. Harbor porpoise
movement and foraging were modeled
for baseline periods and then for periods
with seismic surveys as well; the
models demonstrated that temporal (i.e.,
seasonal) variation in individual
energetics and their link to costs
associated with disturbances was key in
predicting population impacts
(Gallagher et al., 2021).
Behavioral change, such as
disturbance manifesting in lost foraging
time, in response to anthropogenic
activities is often assumed to indicate a
biologically significant effect on a
population of concern. However, as
described above, individuals may be
able to compensate for some types and
degrees of shifts in behavior, preserving
their health and thus their vital rates
and population dynamics. For example,
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New et al. (2013) developed a model
simulating the complex social, spatial,
behavioral, and motivational
interactions of coastal bottlenose
dolphins in the Moray Firth, Scotland,
to assess the biological significance of
increased rate of behavioral disruptions
caused by vessel traffic. Despite a
modeled scenario in which vessel traffic
increased from 70 to 470 vessels a year
(a six-fold increase in vessel traffic) in
response to the construction of a
proposed offshore renewables’ facility,
the dolphins’ behavioral time budget,
spatial distribution, motivations, and
social structure remain unchanged.
Similarly, two bottlenose dolphin
populations in Australia were also
modeled over 5 years against a number
of disturbances (Reed et al., 2020), and
results indicated that habitat/noise
disturbance had little overall impact on
population abundances in either
location, even in the most extreme
impact scenarios modeled.
By integrating different sources of
data (e.g., controlled exposure data,
activity monitoring, telemetry tracking,
and prey sampling) into a theoretical
model to predict effects from sonar on
a blue whale’s daily energy intake,
Pirotta et al. (2021) found that tagged
blue whales’ activity budgets, lunging
rates, and ranging patterns caused
variability in their predicted cost of
disturbance. This method may be useful
for future management goals when
appropriate data becomes available to
fully support the model. Harbor
porpoise movement and foraging were
modeled for baseline periods and then
for periods with seismic surveys as well;
the models demonstrated that the
seasonality of the seismic activity was
an important predictor of impact
(Gallagher et al., 2021).
In their table 1, Keen et al. (2021)
summarize the emerging themes in
PCoD models that should be considered
when assessing the likelihood and
duration of exposure and the sensitivity
of a population to disturbance (see table
1 from Keen et al., 2021, below). The
themes are categorized by life history
traits (movement ecology, life history
strategy, body size, and pace of life),
disturbance source characteristics
(overlap with biologically important
areas, duration and frequency, and
nature and context), and environmental
conditions (natural variability in prey
availability and climate change). Keen et
al. (2021) then summarize how each of
these features influence an assessment,
noting, for example, that individual
animals with small home ranges have a
higher likelihood of prolonged or yearround exposure, that the effect of
disturbance is strongly influenced by
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whether it overlaps with biologically
important habitats when individuals are
present, and that continuous disruption
will have a greater impact than
intermittent disruption.
Nearly all PCoD studies and experts
agree that infrequent exposures of a
single day or less are unlikely to impact
individual fitness, let alone lead to
population level effects (Booth et al.,
2016; Booth et al., 2017; Christiansen
and Lusseau, 2015; Farmer et al., 2018;
Wilson et al., 2020; Harwood and Booth,
2016; King et al., 2015; McHuron et al.,
2018; National Academies of Sciences,
Engineering, and Medicine (NAS), 2017;
New et al., 2014; Pirotta et al., 2018a;
Southall et al., 2007; Villegas-Amtmann
et al., 2015). As described through this
notice for the proposed IHA, NMFS
expects that any behavioral disturbance
that would occur due to animals being
exposed to construction activity would
be of a relatively short duration, with
behavior returning to a baseline state
shortly after the acoustic stimuli ceases
or the animal moves far enough away
from the source. Given this, and NMFS’
evaluation of the available PCoD
studies, and the required mitigation
discussed later, any such behavioral
disturbance resulting from Vineyard
Wind’s activities is not expected to
impact individual animals’ health or
have effects on individual animals’
survival or reproduction, thus no
detrimental impacts at the population
level are anticipated. Marine mammals
may temporarily avoid the immediate
area but are not expected to
permanently abandon the area or their
migratory or foraging behavior. Impacts
to breeding, feeding, sheltering, resting,
or migration are not expected nor are
shifts in habitat use, distribution, or
foraging success.
Potential Effects From Vessel Strike
Vessel collisions with marine
mammals, also referred to as vessel
strikes or ship strikes, can result in
death or serious injury of the animal.
Wounds resulting from ship strike may
include massive trauma, hemorrhaging,
broken bones, or propeller lacerations
(Knowlton and Kraus, 2001). An animal
at the surface could be struck directly by
a vessel, a surfacing animal could hit
the bottom of a vessel, or an animal just
below the surface could be cut by a
vessel’s propeller. Superficial strikes
may not kill or result in the death of the
animal. Lethal interactions are typically
associated with large whales, which are
occasionally found draped across the
bulbous bow of large commercial ships
upon arrival in port. Although smaller
cetaceans are more maneuverable in
relation to large vessels than are large
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whales, they may also be susceptible to
strike. 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; Conn and Silber, 2013), although
Kelley et al. (2020) found, through the
use of a simple biophysical model, that
large whales can be seriously injured or
killed by vessels of all sizes. Impact
forces increase with speed, as does the
probability of a strike at a given distance
(Silber et al., 2010; Gende et al., 2011).
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 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. Marine mammal responses to
vessels may include avoidance and
changes in dive pattern (NRC, 2003).
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 occurs and, if so, whether
it results in injury, serious injury, or
mortality (Knowlton and Kraus, 2001;
Laist et al., 2001; Jensen and Silber,
2003; Pace and Silber, 2005; Vanderlaan
and Taggart, 2007; Conn and Silber,
2013). In assessing records in which
vessel speed was known, 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
13 kn.
Jensen and Silber (2003) detailed 292
records of known or probable ship
strikes of all large whale species from
1975 to 2002. Of these, vessel speed at
the time of collision was reported for 58
cases. Of these 58 cases, 39 (or 67
percent) resulted in serious injury or
death (19 of those resulted in serious
injury as determined by blood in the
water, propeller gashes or severed
tailstock, and fractured skull, jaw,
vertebrae, hemorrhaging, massive
bruising, or other injuries noted during
necropsy and 20 resulted in death).
Operating speeds of vessels that struck
various species of large whales ranged
from 2 to 51 kn. The majority (79
percent) of these strikes occurred at
speeds of 13 kn or greater. The average
speed that resulted in serious injury or
death was 18.6 kn. Pace and Silber
(2005) found that the probability of
death or serious injury increased rapidly
with increasing vessel speed.
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Specifically, the predicted probability of
serious injury or death increased from
45 to 75 percent as vessel speed
increased from 10 to 14 kn and
exceeded 90 percent at 17 kn. Higher
speeds during collisions result in greater
force of impact and also appear to
increase the chance of severe injuries or
death. While modeling studies have
suggested that hydrodynamic forces
pulling whales toward the vessel hull
increase with increasing speed (Clyne,
1999; Knowlton et al., 1995), this is
inconsistent with Silber et al. (2010),
which demonstrated that there is no
such relationship (i.e., hydrodynamic
forces are independent of speed).
In a separate study, Vanderlaan and
Taggart (2007) analyzed the probability
of lethal mortality of large whales at a
given speed, showing that the greatest
rate of change in the probability of a
lethal injury to a large whale as a
function of vessel speed occurs between
8.6 and 15 kn. The chances of a lethal
injury decline from approximately 80
percent at 15 kn to approximately 20
percent at 8.6 kn. At speeds below 11.8
kn, the chances of lethal injury drop
below 50 percent, while the probability
asymptotically increases toward 100
percent above 15 kn.
The Jensen and Silber (2003) report
notes that the Large Whale Ship Strike
Database represents a minimum number
of collisions, because the vast majority
probably goes undetected or unreported.
In contrast, the Project’s personnel are
likely to detect any strike that does
occur because of the required personnel
training and lookouts, along with the
inclusion of PSOs (as described in the
Proposed Mitigation section), and they
are required to report all ship strikes
involving marine mammals.
There are no known vessel strikes of
marine mammals by any offshore wind
energy vessel in the United States.
Given the extensive mitigation and
monitoring measures (see the Proposed
Mitigation and Proposed Monitoring
and Reporting section) that would be
required of Vineyard Wind, NMFS
believes that a vessel strike is not likely
to occur.
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Potential Effects to Marine Mammal
Habitat
Vineyard Wind’s proposed activities
could potentially affect marine mammal
habitat through impacts on the prey
species of marine mammals (through
noise, oceanographic processes, or reef
effects), acoustic habitat (sound in the
water column), water quality, and
biologically important habitat for
marine mammals.
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Effects on Prey
Sound may affect marine mammals
through impacts on the abundance,
behavior, or distribution of prey species
(e.g., crustaceans, cephalopods, fish,
and 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 and Mann, 1999; Fay, 2009). The
most likely effects on fishes exposed to
loud, intermittent, low-frequency
sounds are behavioral responses (i.e.,
flight or avoidance). Short duration,
sharp sounds (such as pile driving or
airguns) can cause overt or subtle
changes in fish behavior and local
distribution. The reaction of fish to
acoustic sources depends on the
physiological state of the fish, past
exposures, motivation (e.g., feeding,
spawning, migration), and other
environmental factors. Key impacts to
fishes may include behavioral
responses, hearing damage, barotrauma
(pressure-related injuries), and
mortality. While it is clear that the
behavioral responses of individual prey,
such as displacement or other changes
in distribution, can have direct impacts
on the foraging success of marine
mammals, the effects on marine
mammals of individual prey that
experience hearing damage, barotrauma,
or mortality is less clear, though
obviously population scale impacts that
meaningfully reduce the amount of prey
available could have more serious
impacts.
Fishes, like other vertebrates, have a
variety of different sensory systems to
glean information from ocean around
them (Astrup and Mohl, 1993; Astrup,
1999; Braun and Grande, 2008; Carroll
et al., 2017; Hawkins and Johnstone,
1978; Ladich and Popper, 2004; Ladich
and Schulz-Mirbach, 2016; Mann, 2016;
Nedwell et al., 2004; Popper et al., 2003,
2005). 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) (terrestrial
vertebrates generally only detect
pressure). Most marine fishes primarily
detect particle motion using the inner
ear and lateral line system while some
fishes possess additional morphological
adaptations or specializations that can
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enhance their sensitivity to sound
pressure, such as a gas-filled swim
bladder (Braun and Grande, 2008;
Popper and Fay, 2011).
Hearing capabilities vary considerably
between different fish species with data
only available for just over 100 species
out of the 34,000 marine and freshwater
fish species (Eschmeyer and Fong,
2016). In order to better understand
acoustic impacts on fishes, fish hearing
groups are defined by species that
possess a similar continuum of
anatomical features, which result in
varying degrees of hearing sensitivity
(Popper and Hastings, 2003). There are
four hearing groups defined for all fish
species (modified from Popper et al.,
2014) within this analysis, and they
include: fishes without a swim bladder
(e.g., flatfish, sharks, rays, etc.); fishes
with a swim bladder not involved in
hearing (e.g., salmon, cod, pollock, etc.);
fishes with a swim bladder involved in
hearing (e.g., sardines, anchovy, herring,
etc.); and fishes with a swim bladder
involved in hearing and high-frequency
hearing (e.g., shad and menhaden). Most
marine mammal fish prey species would
not be likely to perceive or hear mid- or
high-frequency sonars. While hearing
studies have not been done on sardines
and northern anchovies, it would not be
unexpected for them to have hearing
similarities to Pacific herring (up to 2–
5 kHz) (Mann et al., 2005). Currently,
less data are available to estimate the
range of best sensitivity for fishes
without a swim bladder.
In terms of physiology, multiple
scientific studies have documented a
lack of mortality or physiological effects
to fish from exposure to low- and midfrequency sonar and other sounds
(Halvorsen et al., 2012a; J2014
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Strait, type 1 soniferous fish chorusing
showed a relatively lower intensity and
longer duration while type 2 chorusing
exhibited higher intensity and no
changes in its duration. Deviation from
regular fish vocalization patterns may
affect fish reproductive success, cause
migration, augmented predation, or
physiological alterations.
Occasional behavioral reactions to
activities that produce underwater noise
sources are unlikely to cause long-term
consequences for individual fish or
populations. The most likely impact to
fish from impact and vibratory pile
driving activities at the LIAs would be
temporary behavioral avoidance of the
area. 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. The duration of fish
avoidance of an area after pile driving
stops 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 individual pile driving events and the
relatively small areas being affected.
Occasional behavioral reactions to
activities that produce underwater noise
sources are unlikely to cause long-term
consequences for individual fish or
populations. The most likely impact to
fish from impact pile driving activities
at the LIA would be temporary
behavioral avoidance of the area. 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. The duration of fish
avoidance of an area after pile driving
stops 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 individual pile driving events and the
relatively small areas being affected.
As described in the Proposed
Mitigation section below, Vineyard
Wind would utilize a sound attenuation
device which would reduce potential
for injury to marine mammal prey.
Other fish that experience hearing loss
as a result of exposure to impulsive
sound sources may have a reduced
ability to detect relevant sounds such as
predators, prey, or social vocalizations.
However, PTS has not been known to
occur in fishes and any hearing loss in
fish may be as temporary as the
timeframe required to repair or replace
the sensory cells that were damaged or
destroyed (Popper et al., 2005, 2014;
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31033
Smith, 2006). It is not known if damage
to auditory nerve fibers could occur,
and if so, whether fibers would recover
during this process. In addition, most
acoustic effects, if any, are expected to
be short-term and localized. Long-term
consequences for fish populations,
including key prey species within the
LIA, would not be expected.
Required soft-starts would allow prey
and marine mammals to move away
from the source prior to any noise levels
that may physically injure prey and the
use of the noise attenuation devices
would reduce noise levels to the degree
any mortality or injury of prey is also
minimized. Use of bubble curtains, in
addition to reducing impacts to marine
mammals, for example, is a key
mitigation measure in reducing injury
and mortality of ESA-listed salmon on
the U.S. west coast. However, we
recognize some mortality, physical
injury and hearing impairment in
marine mammal prey may occur, but we
anticipate the amount of prey impacted
in this manner is minimal compared to
overall availability. Any behavioral
responses to pile driving by marine
mammal prey are expected to be brief.
We expect that other impacts, such as
stress or masking, would occur in fish
that serve as marine mammals prey
(Popper et al., 2019); however, those
impacts would be limited to the
duration of impact pile driving, and, if
prey were to move out the area in
response to noise, these impacts would
be minimized.
In addition to fish, prey sources such
as marine invertebrates could
potentially be impacted by noise
stressors as a result of the proposed
activities. However, most marine
invertebrates’ ability to sense sounds is
limited. Invertebrates appear to be able
to detect sounds (Pumphrey, 1950;
Frings and Frings, 1967) and are most
sensitive to low-frequency sounds
(Packard et al., 1990; Budelmann and
Williamson, 1994; Lovell et al., 2005;
Mooney et al., 2010). Data on response
of invertebrates such as squid, another
marine mammal prey species, to
anthropogenic sound is more limited
(de Soto, 2016; Sole et al., 2017). Data
suggest that cephalopods are capable of
sensing the particle motion of sounds
and detect low frequencies up to 1–1.5
kHz, depending on the species, and so
are likely to detect airgun noise (Kaifu
et al., 2008; Hu et al., 2009; Mooney et
al., 2010; Samson et al., 2014). Sole et
al. (2017) reported physiological
injuries to cuttlefish in cages placed atsea when exposed during a controlled
exposure experiment to low-frequency
sources (315 Hz, 139 to 142 dB re 1
mPa2; 400 Hz, 139 to 141 dB re 1 mPa2).
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Fewtrell and McCauley (2012) reported
squids maintained in cages displayed
startle responses and behavioral changes
when exposed to seismic airgun sonar
(136–162 re 1 mPa2 × s). Jones et al.
(2020) found that when squid
(Doryteuthis pealeii) were exposed to
impulse pile driving noise, body pattern
changes, inking, jetting, and startle
responses were observed and nearly all
squid exhibited at least one response.
However, these responses occurred
primarily during the first eight impulses
and diminished quickly, indicating
potential rapid, short-term habituation.
Cephalopods have a specialized
sensory organ inside the head called a
statocyst that may help an animal
determine its position in space
(orientation) and maintain balance
(Budelmann, 1992). Packard et al.
(1990) showed that cephalopods were
sensitive to particle motion, not sound
pressure, and Mooney et al. (2010)
demonstrated that squid statocysts act
as an accelerometer through which
particle motion of the sound field can be
detected. Auditory injuries (lesions
occurring on the statocyst sensory hair
cells) have been reported upon
controlled exposure to low-frequency
sounds, suggesting that cephalopods are
particularly sensitive to low-frequency
sound (Andre et al., 2011; Sole et al.,
2013). Behavioral responses, such as
inking and jetting, have also been
reported upon exposure to lowfrequency sound (McCauley et al., 2000;
Samson et al., 2014). Squids, like most
fish species, are likely more sensitive to
low-frequency sounds and may not
perceive mid- and high-frequency
sonars.
With regard to potential impacts on
zooplankton, McCauley et al. (2017)
found that exposure to airgun noise
resulted in significant depletion for
more than half the taxa present and that
there were two to three times more dead
zooplankton after airgun exposure
compared with controls for all taxa,
within 1 km (0.6 mi) of the airguns.
However, the authors also stated that in
order to have significant impacts on
r-selected species (i.e., those with high
growth rates and that produce many
offspring) such as plankton, the spatial
or temporal scale of impact must be
large in comparison with the ecosystem
concerned, and it is possible that the
findings reflect avoidance by
zooplankton rather than mortality
(McCauley et al., 2017). In addition, the
results of this study are inconsistent
with a large body of research that
generally finds limited spatial and
temporal impacts to zooplankton as a
result of exposure to airgun noise (e.g.,
Dalen and Knutsen, 1987; Payne, 2004;
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Stanley et al., 2011). Most prior research
on this topic, which has focused on
relatively small spatial scales, has
showed minimal effects (e.g.,
Kostyuchenko, 1973; Booman et al.,
1996; S#tre and Ona, 1996; Pearson et
al., 1994; Bolle et al., 2012).
A modeling exercise was conducted
as a follow-up to the McCauley et al.
(2017) study (as recommended by
McCauley et al., 2017), in order to assess
the potential for impacts on ocean
ecosystem dynamics and zooplankton
population dynamics (Richardson et al.,
2017). Richardson et al. (2017) found
that a full-scale airgun survey would
impact copepod abundance within the
survey area, but that effects at a regional
scale were minimal (2 percent decline
in abundance within 150 km (93.2 mi)
of the survey area and effects not
discernible over the full region). The
authors also found that recovery within
the survey area would be relatively
quick (3 days following survey
completion) and suggest that the quick
recovery was due to the fast growth
rates of zooplankton, and the dispersal
and mixing of zooplankton from both
inside and outside of the impacted
region. The authors also suggest that
surveys in areas with more dynamic
ocean circulation in comparison with
the study region and/or with deeper
waters (i.e., typical offshore wind
locations) would have less net impact
on zooplankton.
Notably, a recently described study
produced results inconsistent with
those of McCauley et al. (2017).
Researchers conducted a field and
laboratory study to assess if exposure to
airgun noise affects mortality, predator
escape response, or gene expression of
the copepod Calanus finmarchicus
(Fields et al., 2019). Immediate
mortality of copepods was significantly
higher, relative to controls, at distances
of 5 m or less from the airguns.
Mortality 1 week after the airgun blast
was significantly higher in the copepods
placed 10 m from the airgun but was not
significantly different from the controls
at a distance of 20 m from the airgun.
The increase in mortality, relative to
controls, did not exceed 30 percent at
any distance from the airgun. Moreover,
the authors caution that even this higher
mortality in the immediate vicinity of
the airguns may be more pronounced
than what would be observed in freeswimming animals due to increased
flow speed of fluid inside bags
containing the experimental animals.
There were no sub-lethal effects on the
escape performance, or the sensory
threshold needed to initiate an escape
response, at any of the distances from
the airgun that were tested. Whereas
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McCauley et al. (2017) reported an SEL
of 156 dB at a range of 509–658 m, with
zooplankton mortality observed at that
range, Fields et al. (2019) reported an
SEL of 186 dB at a range of 25 m, with
no reported mortality at that distance.
Airguns and impact pile driving are
similar in that they both produce
impulsive and intermittent noise and
typically have higher source levels than
other sources (e.g., vibratory driving).
We anticipate marine mammal prey
exposed to impact pile driving would
demonstrate similar physical
consequences and behavioral impacts
compared to exposure to airguns;
however, the spatial extent of these
impacts during impact pile driving is
dependent upon source levels and use
of noise attenuation systems (NAS) such
as double bubble curtains, such that
lower source levels and use of NAS are
expected to further minimize impacts
that would occur otherwise.
The presence of large numbers of
turbines has been shown to impact
meso- and sub-meso-scale water column
circulation, which can affect the
density, distribution, and energy
content of zooplankton and thereby,
their availability as marine mammal
prey. Topside, atmospheric wakes result
in wind speed reductions influencing
upwelling and downwelling in the
ocean while underwater structures such
as WTG and ESP foundations may cause
turbulent current wakes, which impact
circulation, stratification, mixing, and
sediment resuspension (Daewel et al.,
2022). Overall, the presence of
structures such as wind turbines is, in
general, likely to result in certain
oceanographic effects in the marine
environment and may alter marine
mammal prey, such as aggregations and
distribution of zooplankton through
changing the strength of tidal currents
and associated fronts, changes in
stratification, primary production, the
degree of mixing, and stratification in
the water column (Chen et al., 2021;
Johnson et al., 2021; Christiansen et al.,
2022; Dorrell et al., 2022).
Turbine operations for the previously
installed 47 WTG monopile foundations
commenced in 2023. Vineyard Wind
intends to install 15 WTG monopile
foundations, and it is possible that
turbines would become operational by
the end of the IHA effective period. As
described below (see Potential Effects
from Offshore Wind Farm Operational
Noise section), there is scientific
uncertainty around the scale of
oceanographic impacts (meters to
kilometers) associated with turbine
operation. The Project is located
offshore of Massachusetts, and although
the LIA does overlap with key winter
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foraging grounds for NARWs (Leiter et
al., 2017; Quintana-Rizzo et al., 2021;
O’Brien et al., 2022; Pendleton et al.,
2022), nearby habitat may provide
higher foraging value should NARW
prey be affected in the LIA during
construction, and the amount of pile
driving time with only 15 piles
remaining to be installed is expected to
be limited, thereby limiting potential
impacts on prey aggregation. In
addition, the proposed seasonal
restriction on pile driving from January
through May would reduce impacts to
NARW prey during the time that they
are more likely to be foraging. The LIA
does not overlap but is in proximity to
seasonal foraging grounds for fin
whales, minke whales, and sei whales.
Generally speaking, and depending on
the extent, impacts on prey could
impact the distribution of marine
mammals in an area, potentially
necessitating additional energy
expenditure to find and capture prey.
However, at the temporal and spatial
scales anticipated for this activity, any
such impacts on prey are not expected
to impact the reproduction or survival
of any individual marine mammals.
Although studies assessing the impacts
of offshore wind development on
marine mammals are limited, the
repopulation of wind energy areas by
harbor porpoises (Brandt et al., 2016;
Lindeboom et al., 2011) and harbor seals
(Lindeboom et al., 2011; Russell et al.,
2016) following the installation of wind
turbines are promising. Overall, any
impacts to marine mammal foraging
capabilities due to effects on prey
aggregation from the turbine presence
and operation during the effective
period of the proposed IHA is likely to
be limited. In general, impacts to marine
mammal prey species are expected to be
relatively minor and temporary due to
the expected short daily duration of
individual pile driving events and the
relatively small areas being affected.
Reef Effects
The presence of monopile
foundations and scour protection will
result in a conversion of the existing
sandy bottom habitat to a hard bottom
habitat with areas of vertical structural
relief. This could potentially alter the
existing habitat by creating an ‘‘artificial
reef effect’’ that results in colonization
by assemblages of both sessile and
mobile animals within the new hardbottom habitat (Wilhelmsson et al.,
2006; Reubens et al., 2013; Bergstro¨m et
al., 2014; Coates et al., 2014). This
colonization by marine species,
especially hard-substrate preferring
species, can result in changes to the
diversity, composition, and/or biomass
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of the area thereby impacting the
trophic composition of the site
(Wilhelmsson et al., 2010; Krone et al.,
2013; Bergstro¨m et al., 2014; Hooper et
al., 2017; Raoux et al., 2017; Harrison
and Rousseau, 2020; Taormina et al.,
2020; Buyse et al., 2022a; ter Hofstede
et al., 2022).
Artificial structures can create
increased habitat heterogeneity
important for species diversity and
density (Langhamer, 2012). The
monopile WTG foundations will extend
through the water column, which may
serve to increase settlement of
meroplankton or planktonic larvae on
the structures in both the pelagic and
benthic zones (Boehlert and Gill, 2010).
Fish and invertebrate species are also
likely to aggregate around the
foundations and scour protection which
could provide increased prey
availability and structural habitat
(Boehlert and Gill, 2010; Bonar et al.,
2015). Further, instances of species
previously unknown, rare, or
nonindigenous to an area have been
documented at artificial structures,
changing the composition of the food
web and possibly the attractability of
the area to new or existing predators
(Adams et al., 2014; de Mesel, 2015;
Bishop et al., 2017; Hooper et al., 2017;
Raoux et al., 2017; van Hal et al., 2017;
Degraer et al., 2020; Fernandez-Betelu et
al., 2022). Notably, there are examples
of these sites becoming dominated by
marine mammal prey species, such as
filter-feeding species and suspensionfeeding crustaceans (Andersson and
¨ hman, 2010; Slavik et al., 2019;
O
Hutchison et al., 2020; Pezy et al., 2020;
Mavraki et al., 2022).
Numerous studies have documented
significantly higher fish concentrations
including species like cod and pouting
(Trisopterus luscus), flounder
(Platichthys flesus), eelpout (Zoarces
viviparus), and eel (Anguilla anguilla)
near in-water structures than in
surrounding soft bottom habitat
(Langhamer and Wilhelmsson, 2009;
Bergstro¨m et al., 2013; Reubens et al.,
2013). In the German Bight portion of
the North Sea, fish were most densely
congregated near the anchorages of
jacket foundations, and the structures
extending through the water column
were thought to make it more likely that
juvenile or larval fish encounter and
settle on them (Rhode Island Coastal
Resources Management Council, 2010;
Krone et al., 2013). In addition, fish can
take advantage of the shelter provided
by these structures while also being
exposed to stronger currents created by
the structures, which generate increased
feeding opportunities and decreased
potential for predation (Wilhelmsson et
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al., 2006). The presence of the
foundations and resulting fish
aggregations around the foundations is
expected to be a long-term habitat
impact, but the increase in prey
availability could potentially be
beneficial for some marine mammals.
Water Quality
Temporary and localized reduction in
water quality will occur as a result of
pile driving activities. These activities
will disturb bottom sediments and may
cause a temporary increase in
suspended sediment in the LIA.
Currents should quickly dissipate any
raised total suspended sediment (TSS)
levels, and levels should return to
background levels once the project
activities in that area cease. No direct
impacts on marine mammals are
anticipated due to increased TSS and
turbidity; however, turbidity within the
water column has the potential to
reduce the level of oxygen in the water
and irritate the gills of prey fish species
in the LIA. However, turbidity plumes
associated with the project would be
temporary and localized, and fish in the
LIA would be able to move away from
and avoid the areas where plumes may
occur. Therefore, it is expected that the
impacts on prey fish species from
turbidity, and therefore on marine
mammals, would be minimal and
temporary.
Equipment used by Vineyard Wind
within the LIA, including ships and
other marine vessels, potentially
aircrafts, and other equipment, are also
potential sources of by-products (e.g.,
hydrocarbons, particulate matter, heavy
metals). All equipment is properly
maintained in accordance with
applicable legal requirements. All such
operating equipment meets Federal
water quality standards, where
applicable. Given these requirements,
impacts to water quality are expected to
be minimal.
Acoustic Habitat
Acoustic habitat is the soundscape,
which encompasses all of the sound
present in a particular location and
time, as a whole when considered from
the perspective of the animals
experiencing it. Animals produce sound
for, or listen for sounds produced by,
conspecifics (communication during
feeding, mating, and other social
activities), other animals (finding prey
or avoiding predators), and the physical
environment (finding suitable habitats,
navigating). Together, sounds made by
animals and the geophysical
environment (e.g., produced by
earthquakes, lightning, wind, rain,
waves) make up the natural
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contributions to the total acoustics of a
place. These acoustic conditions,
termed acoustic habitat, are one
attribute of an animal’s total habitat.
Soundscapes are defined and
influenced by the total contribution of
anthropogenic sound. This may include
incidental emissions from sources such
as vessel traffic or may be intentionally
introduced to the marine environment
for data acquisition purposes (as in the
use of airgun arrays) or for Navy training
and testing purposes (as in the use of
sonar and explosives and other acoustic
sources). Anthropogenic noise varies
widely in its frequency, content,
duration, and loudness. These
characteristics greatly influence the
potential habitat-mediated effects to
marine mammals (please also see the
previous discussion on Masking), which
may range from local effects for brief
periods of time to chronic effects over
large areas and for long durations.
Depending on the extent of effects to
habitat, animals may alter their
communications signals (thereby
potentially expending additional
energy) or miss acoustic cues (either
conspecific or adventitious). Problems
arising from a failure to detect cues are
more likely to occur when noise stimuli
are chronic and overlap with
biologically relevant cues used for
communication, orientation, and
predator/prey detection (Francis and
Barber, 2013). For more detail on these
concepts, see: Barber et al., 2009;
Pijanowski et al., 2011; Francis and
Barber, 2013; Lillis et al., 2014.
The term ‘‘listening area’’ refers to the
region of ocean over which sources of
sound can be detected by an animal at
the center of the space. Loss of
communication space concerns the area
over which a specific animal signal,
used to communicate with conspecifics
in biologically important contexts (e.g.,
foraging, mating), can be heard, in
noisier relative to quieter conditions
(Clark et al., 2009). Lost listening area
concerns the more generalized
contraction of the range over which
animals would be able to detect a
variety of signals of biological
importance, including eavesdropping on
predators and prey (Barber et al., 2009).
Such metrics do not, in and of
themselves, document fitness
consequences for the marine animals
that live in chronically noisy
environments. Long-term populationlevel consequences mediated through
changes in the ultimate survival and
reproductive success of individuals are
difficult to study, and particularly so
underwater. However, it is increasingly
well documented that aquatic species
rely on qualities of natural acoustic
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habitats, with researchers quantifying
reduced detection of important
ecological cues (e.g., Francis and Barber,
2013; Slabbekoorn et al., 2010) as well
as survivorship consequences in several
species (e.g., Simpson et al., 2014;
Nedelec et al., 2014).
Potential Effects From Offshore Wind
Farm Operational Noise
Although this proposed IHA primarily
covers the noise produced from
construction activities relevant to the
Vineyard Wind Offshore Wind Project
offshore wind facility, operational noise
was a consideration in NMFS’ analysis
of the project, as turbines may become
operational within the effective dates of
the IHA (if issued).
In both newer, quieter, direct-drive
systems and older generation, geared
turbine designs, recent scientific studies
indicate that operational noise from
turbines is on the order of 110 to 125 dB
re 1 mPa root-mean-square sound
pressure level (SPLrms) at an
approximate distance of 50 m (Tougaard
et al., 2020). Recent measurements of
operational sound generated from wind
turbines (direct drive, 6 MW, jacket
foundations) at Block Island wind farm
(BIWF) indicate average broadband
levels of 119 dB at 50 m from the
turbine, with levels varying with wind
speed (HDR, Inc., 2019). Interestingly,
measurements from BIWF turbines
showed operational sound had fewer
tonal components compared to
European measurements of turbines
with gear boxes.
Tougaard et al. (2020) further stated
that the operational noise produced by
WTGs is static in nature and lower than
noise produced by passing ships. This is
a noise source in this region to which
marine mammals are likely already
habituated. Furthermore, operational
noise levels are likely lower than those
ambient levels already present in active
shipping lanes, such that operational
noise would likely only be detected in
very close proximity to the WTG
(Thomsen et al., 2006; Tougaard et al.,
2020). Similarly, recent measurements
from a wind farm (3–MW turbines) in
China found that above 300 Hz, turbines
produced sound that was similar to
background levels (Zhang et al., 2021).
Other studies by Jansen and de Jong
(2016) and Tougaard et al. (2009)
determined that, while marine
mammals would be able to detect
operational noise from offshore wind
farms (again, based on older 2–MW
models) for several kilometers, they
expected no significant impacts on
individual survival, population
viability, marine mammal distribution,
or the behavior of the animals
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considered in their study (harbor
porpoises and harbor seals). In addition,
Madsen et al. (2006) found the intensity
of noise generated by operational wind
turbines to be much less than the noises
present during construction, although
this observation was based on a single
turbine with a maximum power of 2
MW.
More recently, Sto¨ber and Thomsen
(2021) used monitoring data and
modeling to estimate noise generated by
more recently developed, larger (10–
MW) direct-drive WTGs. Their findings,
similar to Tougaard et al. (2020),
demonstrate that there is a trend that
operational noise increases with turbine
size. Their study predicts broadband
source levels could exceed 170-dB
SPLrms for a 10–MW WTG; however,
those noise levels were generated based
on geared turbines whereas newer
turbines operate with direct drive
technology. The shift from using gear
boxes to direct drive technology is
expected to reduce the levels by 10 dB.
The findings in the Sto¨ber and Thomsen
(2021) study have not been
experimentally validated, though the
modeling (using largely geared turbines)
performed by Tougaard et al. (2020)
yields similar results for a hypothetical
10–MW WTG.
Recently, Holme et al. (2023)
cautioned that the Tougaard et al. (2020)
and Sto¨ber and Thomsen (2021) studies
extrapolated levels for larger turbines
should be interpreted with caution since
both studies relied on data from smaller
turbines (0.45 to 6.15 MW) collected
over a variety of environmental
conditions. Holme et al. (2023)
demonstrated that the model presented
in Tougaard et al. (2020) tends to
potentially overestimate levels (up to
approximately 8 dB) measured to those
in the field, especially with
measurements closer to the turbine for
larger turbines. Holme et al. (2023)
measured operational noise from larger
turbines (6.3 and 8.3 MW) associated
with three wind farms in Europe and
found no relationship between turbine
activity (power production, which is
proportional to the blade’s revolutions
per minute) and noise level, though it
was noted that this missing relationship
may have been masked by the area’s
relatively high ambient noise sound
levels. Sound levels (rms) of a 6.3–MW
direct-drive turbine were measured to
be 117.3 dB at a distance of 70 m.
However, measurements from 8.3 MW
turbines were inconclusive as turbine
noise was deemed to have been largely
masked by ambient noise.
Finally, operational turbine
measurements are available from the
Coastal Virginia Offshore Wind (CVOW)
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pilot pile project, where two 7.8 m
monopile WTGs were installed (HDR,
2023). Compared to BIWF, levels at
CVOW were higher (10–30 dB) below
120 Hz, believed to be caused by the
vibrations associated with the monopile
structure, while above 120 Hz levels
were consistent among the two wind
farms.
Overall, noise from operating turbines
would raise ambient noise levels in the
immediate vicinity of the turbines;
however, the spatial extent of increased
noise levels would be limited. Vineyard
Wind did not request, and NMFS is not
proposing to authorize, take incidental
to operational noise from WTGs.
Therefore, the topic is not discussed or
analyzed further herein. However,
NMFS proposes to require Vineyard
Wind to measure operational noise
levels.
Estimated Take of Marine Mammals
This section provides an estimate of
the number of incidental takes proposed
for authorization through the IHA,
which will inform NMFS’ consideration
of ‘‘small numbers,’’ the negligible
impact determinations, and impacts on
subsistence uses.
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).
Proposed takes would primarily be by
Level B harassment, as noise from pile
driving has the potential to result in
disruption of marine mammal
behavioral patterns. Impacts such as
masking and TTS can contribute to the
disruption of behavioral patterns and
are accounted for within those takes
proposed for authorization. There is also
some potential for high frequency
species (harbor porpoise) and phocids
(harbor seal and gray seal) to experience
a limited amount of auditory injury
(PTS; Level A harassment) primarily
because predicted auditory injury zones
are large enough and these species are
cryptic enough that the potential for
PTS cannot be fully discounted. For
mysticetes, the Level A harassment
ER95percent ranges are also large (0.0043
km to 3.191 km); however, the extensive
marine mammal mitigation and
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monitoring proposed by Vineyard Wind,
and which would be required by NMFS,
as well as natural avoidance behaviors
is expected to reduce the potential for
PTS to discountable levels.
Nevertheless, Vineyard Wind has
requested, and NMFS proposes to
authorize a small amount of Level A
harassment incidental to installing piles
(table 11). Auditory injury is unlikely to
occur for mid-frequency species as
thresholds are higher and PTS zones are
very close to the pile such that PTS is
unlikely to occur. While NMFS is
proposing to authorize Level A
harassment and Level B harassment, the
proposed mitigation and monitoring
measures are expected to, in some cases,
avoid,and minimize overall the severity
of the taking to the extent practicable
(see Proposed Mitigation and Proposed
Monitoring and Reporting sections).
As described previously, no serious
injury or mortality is anticipated or
proposed to be authorized incidental to
the specified activity. Even without
mitigation, pile driving activities are
unlikely to directly cause marine
mammal mortality or serious injury.
There is no documented case wherein
pile driving resulted in marine mammal
mortality or stranding and the scientific
literature demonstrates that the most
likely behavioral response to pile
driving (or similar stimulus source) is
avoidance and temporary cessation of
behaviors such as foraging or
socialization (see Avoidance and
Displacement in Potential Effects of
Specified Activities on Marine
Mammals and Their Habitat section).
While, in general, there is a low
probability that mortality or serious
injury of marine mammals could occur
from vessel strikes, the mitigation and
monitoring measures contained within
this proposed rule are expected to avoid
vessel strikes (see Proposed Mitigation
section). No other activities have the
potential to result in mortality or serious
injury.
For acoustic impacts, we estimate take
by considering: (1) acoustic thresholds
above which NMFS believes the best
available science indicates marine
mammals will be behaviorally harassed
or incur some degree of permanent
hearing impairment; (2) the area or
volume of water that will be ensonified
above these levels in a day; (3) the
density or occurrence of marine
mammals within these ensonified areas;
and, (4) the number of days of activities.
We note that while these factors can
contribute to a basic calculation to
provide an initial prediction of potential
takes, additional information that can
qualitatively inform take estimates is
also sometimes available (e.g., previous
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monitoring results or average group
size). Below, we describe the factors
considered here in more detail and
present the proposed take estimates.
As described below, there are
multiple methods available to estimate
the density or number of a given species
in the area appropriate to inform the
take estimate. For each species and
activity, the largest value resulting from
the three take estimation methods
described below (i.e., density-based,
PSO-based, or mean group size) was
carried forward as the amount of take
proposed for authorization, by Level B
harassment. The amount of take
proposed for authorization, by Level A
harassment, reflects the density-based
exposure estimates and, for some
species and activities, consideration of
other data such as mean group size.
Below, we describe NMFS’ acoustic
thresholds, acoustic and exposure
modeling methodologies, marine
mammal density calculation
methodology, occurrence information,
and the modeling and methodologies
applied to estimate take for the Project’s
proposed construction activities. NMFS
considered all information and analysis
presented by Vineyard Wind, as well as
all other applicable information and,
based on the best available science,
concurs that the estimates of the types
and amounts of take for each species
and stock are reasonable, and is
proposing to authorize the amount
requested. NMFS notes the take
estimates described herein for
foundation installation can be
considered conservative because the
estimates do not reflect the
implementation of clearance and
shutdown zones for any marine
mammal species or stock.
Acoustic Thresholds
NMFS recommends the use of
acoustic thresholds that identify the
received level of underwater sound
above which exposed marine mammals
are likely to be behaviorally harassed
(Level B harassment) or to incur PTS of
some degree (Level A harassment). A
summary of all NMFS’ thresholds can
be found at https://www.fisheries.
noaa.gov/national/marine-mammalprotection/marine-mammal-acoustictechnical-guidance.
Level B Harassment
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 or exposure context (e.g.,
frequency, predictability, duty cycle,
duration of the exposure, signal-to-noise
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ratio, distance to the source, ambient
noise, and the receiving animal’s
hearing, motivation, experience,
demography, behavior at time of
exposure, life stage, depth) and can be
difficult to predict (e.g., Southall et al.,
2007, 2021; Ellison et al., 2012). Based
on what the available science indicates
and the practical need to use a threshold
based on a metric that is both
predictable and measurable for most
activities, NMFS typically uses a
generalized acoustic threshold based on
received level to estimate the onset of
behavioral harassment.
NMFS generally predicts that marine
mammals are likely to be taken in a
manner considered to be Level B
harassment when exposed to
underwater anthropogenic noise above
root-mean-squared pressure received
levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 mPa)) for
continuous (e.g., vibratory pile driving,
drilling) and above RMS SPL 160 dB re
1 mPa for non-explosive impulsive (e.g.,
seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally
speaking, Level B harassment take
estimates based on these thresholds are
expected to include any likely takes by
TTS as, in most cases, the likelihood of
TTS occurs at closer distances from the
source. TTS of a sufficient degree can
manifest as behavioral harassment, as
reduced hearing sensitivity and the
potential reduced opportunities to
detect important signals (conspecific
communication, predators, prey) may
result in changes in behavior patterns
that would not otherwise occur.
The proposed Project’s construction
activities include the use of impulsive
sources (e.g., impact pile driving), and
therefore the 160-dB re 1 mPa (rms)
threshold is applicable to our analysis.
Level A Harassment
NMFS’ Technical Guidance for
Assessing the Effects of Anthropogenic
Sound on Marine Mammal Hearing
(Version 2.0, Technical Guidance;
NMFS, 2018) identifies dual criteria to
assess auditory injury (Level A
harassment) to five different marine
mammal groups (based on hearing
sensitivity) as a result of exposure to
noise from two different types of
sources (impulsive or non-impulsive).
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). As
described above, Vineyard Wind’s
proposed activities include the use of
impulsive sources. NMFS’ thresholds
identifying the onset of PTS are
provided in table 5. The references,
analysis, and methodology used in the
development of the thresholds are
described in NMFS’ 2018 Technical
Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/
national/marine-mammal-protection/
marine-mammal-acoustic-technicalguidance.
TABLE 5—PTS ONSET THRESHOLDS
[NMFS, 2018]
PTS onset thresholds *
(received level)
Hearing group
Impulsive
Low-Frequency (LF) Cetaceans ......................................
Mid-Frequency (MF) Cetaceans ......................................
High-Frequency (HF) Cetaceans .....................................
Phocid Pinnipeds (PW) (Underwater) .............................
Otariid Pinnipeds (OW) (Underwater) .............................
Lp,0-pk,flat:
Lp,0-pk,flat:
Lp,0-pk,flat:
Lp,0-pk,flat:
Lp,0-pk,flat:
219
230
202
218
232
dB;
dB;
dB;
dB;
dB;
Non-impulsive
LE,p, LF,24h: 183 dB ............................
LE,p, MF,24h: 185 dB ...........................
LE,p,HF,24h: 155 dB .............................
LE,p,PW,24h: 185 dB ............................
LE,p,OW,24h: 203 dB ............................
LE,p, LF,24h: 199 dB.
LE,p, MF,24h: 198 dB.
LE,p, HF,24h: 173 dB.
LE,p,PW,24h: 201 dB.
LE,p,OW,24h: 219 dB.
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* Dual metric 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 are recommended
for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 μPa, and weighted cumulative sound exposure level (LE,p) has a reference value of 1μPa2s. In this table, thresholds are abbreviated to be more reflective of International Organization for Standardization standards
(ISO, 2017). The subscript ‘‘flat’’ is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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 weighted 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
thresholds will be exceeded.
Below, we describe the assumptions
and methodologies used to estimate
take, in consideration of acoustic
thresholds and appropriate marine
mammals density and occurrence
information, for WTG monopile
installation. Resulting distances to
thresholds, densities and occurrence
(i.e., PSO sightings, group size) data
used, exposure estimates (as relevant to
the analysis), and activity-specific take
estimates can be found below.
Acoustic and Exposure Modeling
During the 2023 Vineyard Wind pile
installation activities, Vineyard Wind
conducted a sound field verification
(SFV) study to compare with model
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results of the 2018 modeling (Ku¨sel et
al., 2024). The SFV study included
acoustic monitoring of the impact
installation of 12 monopile foundations
from June 6 through September 7, 2023.
Five of the 12 acoustically monitored
monopiles were determined to be
representative of the noise attenuation
system (NAS) configuration and
maintenance schedule that would be
proposed for the remaining 15
monopiles to be installed in 2024. These
five representative monopiles (piles 7, 8,
10, 11, and 12 in the Vineyard Wind
SFV Monitoring Report) were monitored
using a double bubble curtain (DBBC)
and Hydrosound Damper System (HSD),
which has been proposed for use as the
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noise attenuation system setup for the
remaining 15 monopiles. Vineyard
Wind also followed an enhanced bubble
curtain maintenance schedule for these
five monopiles; this maintenance
schedule would also be used for the
remaining 15 monopiles to be installed
in 2024 (see the Vineyard Wind
Enhanced BBC Technical Memo). Peak
(pk), SEL, and RMS SPL received
distances for each acoustically
monitored pile are reported in the VW1
SFV Final Report Appendix A (Ku¨sel et
al., 2024) For additional details on how
acoustic ranges were derived from SFV
measurements, see the VW1 SFV Final
Report sections 2.3 and 3.3 (Ku¨sel et al.,
2024). JASCO modeled a maximum
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range to the Level A harassment
threshold of 3.191 km (1.99 mi) with 6dB attenuation (for low-frequency
cetaceans) (Ku¨sel et al., 2024).
In addition to the 15 piles being
installed under the same noise
attenuation scenario as the 5
aforementioned representative piles,
they are also anticipated to be installed
under similar pile driving specifications
and in a similar acoustic environment.
Table 6 describes the key piling
assumptions and proposed impact pile
driving schedule for 2024. These
assumptions and schedule are based
upon the 2023 piling and hammer
energy schedule for installing
monopiles. Vineyard Wind expects
installation of the 15 remaining piles
will necessitate similar operations.
Further, as described in detail in section
6.1 of Vineyard Wind’s application, the
water depth and bottom type are similar
throughout the Lease Area and therefore
sound propagation in the LIA is not
expected to differ from where the SFV
data were collected in 2023.
TABLE 6—KEY PILING ASSUMPTIONS AND HAMMER ENERGY SCHEDULE FOR MONOPILE INSTALLATION
Max hammer
energy
(kJ)
Pile type
Project
component
9.6-m monopile ...................................
WTG ..............
a The
4,000
Max piling
time duration
per pile (min)
Number of
hammer strikes
2,884–4,329 (average 3,463) a ...........
Number
piles/day
117
1
number of hammer strikes represent the range of strikes needed to install the 12 monopiles for which SFV was conducted in 2023.
Vineyard Wind compared the acoustic
ranges to the Level A harassment and
Level B harassment thresholds derived
from the 2018 acoustic modeling (Pyc´ et
al., 2018) to the maximum ranges with
absorption for the five representative
monopiles acoustically monitored in
2023. They applied the greater results to
the analysis in their application and
NMFS has included that approach in
this proposed IHA. The maximum
measured range to PTS thresholds of the
five representative monopiles was less
than the maximum 2018 modeled
ranges for all hearing groups, assuming
6 dB of attenuation (table 7), with the
exception of high-frequency cetaceans
(although Vineyard Wind attributes this
extended range to non-piling noise
(Vineyard Wind, 2023)). Therefore,
Vineyard Wind based the expected
distance to the Level A harassment
threshold and associated estimated take
analysis on the 2018 modeled data.
TABLE 7—MODELED AND MEASURED RANGES TO SELcum PTS THRESHOLDS FOR MARINE MAMMAL HEARING GROUPS
Modeled range to
SELcum PTS
threshold
(km) a
Marine mammal hearing group
Low-frequency cetaceans ................................................................................................................
Mid-frequency cetaceans .................................................................................................................
High-frequency cetaceans ...............................................................................................................
Phocid pinnipeds .............................................................................................................................
a Based
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b Based
3.191
0.043
0.071
0.153
Measured maximum
range to SELcum PTS
threshold
(km) b
2.37
0.01
0.2
0.1
upon modeling conducted for the 2023 IHA (Pyc´ et al., 2018)
upon the five representative monopiles from the Vineyard Wind 2023 construction campaign (Ku¨sel et al., 2024).
The maximum range with absorption
to the Level B harassment threshold for
acoustically monitored piles was 5.72
km (3.6 mi) (pile 13, AU–38; Ku¨sel et
al., 2024), which was greater than the
2018 modeled distance to the Level B
harassment threshold of 4.1 km (2.5 mi)
(Pyc´ et al., 2018). Therefore, Vineyard
Wind based the expected distance to the
Level B harassment threshold and
associated estimated take analysis on
the 5.72-km acoustically monitored
distance.
In 2018, Vineyard Wind conducted
animat modeling to estimate take, by
Level A harassment (PTS), incidental to
the project. In order to best evaluate the
SELcum harassment thresholds for PTS,
it is necessary to consider animal
movement, as the results are based on
how sound moves through the
environment between the source and
the receiver. Applying animal
movement and behavior within the
modeled noise fields provides the
exposure range, which allows for a more
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realistic indication of the distances at
which PTS acoustic thresholds are
reached that considers the accumulation
of sound over different durations (note
that in all cases the distance to the peak
threshold is less than the SEL-based
threshold). As described above,
Vineyard Wind based the Level A
harassment estimated take analysis on
the modeled Level A harassment
acoustic ranges and therefore
appropriately used the results of the
JASCO’s Animal Simulation Model
Including Noise Exposure (JASMINE)
animal movement modeling conducted
for the 2023 IHA (86 FR 33810, June 25,
2021). Sound exposure models like
JASMINE use simulated animals (also
known as ‘‘animats’’) to forecast
behaviors of animals in new situations
and locations based upon previously
documented behaviors of those animals.
The predicted 3D sound fields (i.e., the
output of the acoustic modeling process
described earlier) are sampled by
animats using movement rules derived
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from animal observations. The output of
the simulation is the exposure history
for each animat within the simulation.
The precise location of animats and
their pathways are not known prior to
a project; therefore, a repeated random
sampling technique (i.e., Monte Carlo) is
used to estimate exposure probability
with many animats and randomized
starting positions. The combined
exposure history of all animats gives a
probability density function of exposure
during the Project.
Since the time that the JASMINE
animal movement modeling was
conducted for the 2023 IHA (86 FR
33810, June 25, 2021), no new behavior
data is available that would have
changed how animats move in time and
space in that model and, therefore,
NMFS has determined that the
JASMINE outputs from the 2018
modeling effort are reasonable for
application here. However, the post
processing calculations used more
recent density data (table 8). The mean
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number of modeled animats exposed
per day with installation of one 9.6-m
monopile were scaled by the maximum
monthly density for the LIA (Roberts et
al., 2023) for each species (table 8) to
estimate the real-world number of
animats of each species that could be
exposed per day in the LIA. This realworld number of animals was
multiplied by the expected number of
days of pile installation (15 days) to
derive a total take estimate by Level A
harassment for each species. The
number of potential exposures by Level
A harassment was estimated for each
species using the following equation:
Density-based exposure estimate of
Level A harassment = number of
animats exposed above the Level A
harassment threshold× ((mean
maximum monthly density
(animals/km2)/modeled 2018
density (animats/km2))×number of
days (15).
To estimate the amount of take by
Level B harassment incidental to
installing the remaining 15 piles,
Vineyard Wind applied a static method
(i.e., did not conduct animal movement
modeling). Vineyard Wind calculated
the Level B harassment ensonified area
using the following equation:
A = 3.14 × r2,
where A is equal to the ensonified area
and r is equal to the radial distance to
the Level B harassment threshold from
the pile driving source (rLevel B harassment
= 5.72 km).
The ensonified area (102.7 km2) was
multiplied by the mean maximum
monthly density estimate (table 8) and
expected number of days of pile driving
(15 days) to determine a density-based
take estimate for each species. The
number of potential exposures by Level
B harassment was estimated for each
species using the following equation:
Density-based exposure estimate of
Level B harassment = ensonified
area (km2) × maximum mean
monthly density estimate (animals/
km2) × number of days (15).
Density and Occurrence and Take
Estimation
In this section we provide information
about marine mammal density,
presence, and group dynamics that
informed the take calculations for the
proposed activities. Vineyard Wind
applied the 2022 Duke University
Marine Geospatial Ecology Laboratory
Habitat-based Marine Mammal Density
Models for the U.S. Atlantic (Duke
Model-Roberts et al., 2016, 2023) to
estimate take from foundation
installation. The models estimate
absolute density (individuals/km2) by
statistically correlating sightings
reported on shipboard and aerial
surveys with oceanographic conditions.
For most marine mammal species,
densities are provided on a monthly
basis. Where monthly densities are not
available (e.g., pilot whales), annual
densities are provided. Moreover, some
species are represented as guilds (e.g.,
seals (representing Phocidae spp.,
primarily harbor and gray seals) and
pilot whales (representing short-finned
and long-finned pilot whales)).
The Duke habitat-based density
models delineate species’ density into 5
× 5 km (3.1 × 3.1 mi) grid cells. Vineyard
Wind calculated mean monthly
densities by using a 10-km buffered
polygon around the remaining WTG
foundations to be installed and
overlaying this buffered polygon on the
density maps. The 10-km buffer defines
the area around the LIA used to
calculate mean species density. Mean
monthly density for each species was
determined by calculating the
unweighted mean of all 5 × 5 km grid
cells (partially or fully) within the
buffered polygon. The unweighted mean
refers to using the entire 5 × 5 km (3.1
× 3.1 mi) grid cell for each cell used in
the analysis, and was not weighted by
the proportion of the cell overlapping
with the density perimeter if the entire
grid cell was not entirely within the
buffer zone polygon. Vineyard Wind
calculated densities for each month,
except for species for which annual
density data only was available (e.g.,
long-finned pilot whale). Vineyard
Wind used maximum monthly density
from June to December for density-based
calculations.
The density models (Roberts et al.,
2023) provided density for pilot whales
and seals as guilds. Based upon habitat
and ranging patterns (Hayes et al.,
2023), all pilot whales occurring in the
LIA are expected to be long-finned pilot
whales. Therefore, all pilot whale
density estimates are assumed to
represent long-finned pilot whales. Seal
guild density was divided into speciesspecific densities based upon the
proportions of each species observed by
PSOs during 2016 and 2018–2021 site
characterizations surveys within SNE
(ESS Group, 2016; Vineyard Wind 2018,
2019, 2023a–f). Of the 181 seals
identified to species and sighted within
the WDA, 162 were gray seals and 19
were harbor seals. The equation below
shows how the proportion of each seal
species sighted was calculated to
compute density for seals.
Pseal species = Nseal species/Numbertotal seals
identified,
where P represents density and N
represents number of seals.
These calculations resulted in
proportions of 0.895 for gray seals and
0.105 for harbor seals. The proportion
for each species was then multiplied by
the maximum monthly density for the
seal guild (table 8) to determine the
species-specific densities used in take
calculations.
The density models (Roberts et al.,
2023) also do not distinguish between
bottlenose dolphin stocks and only
provide densities for bottlenose
dolphins as a species. However, as
described above, based upon ranging
patterns (Hayes et al., 2023), only the
Western North Atlantic offshore stock of
bottlenose dolphins is expected to occur
in the LIA. Therefore, it is expected that
the bottlenose dolphin density estimate
is entirely representative of this stock.
Maximum mean monthly density
estimates and month of the maximum
estimate is provided in table 8 below.
TABLE 8—MAXIMUM MEAN MONTHLY MARINE MAMMAL DENSITY ESTIMATES (ANIMALS PER km2) CONSIDERING A 10-km
BUFFER AROUND THE LIMITED INSTALLATION AREA
ddrumheller on DSK120RN23PROD with NOTICES2
Species
Maximum mean density
NARW * ...................................................................................................................................
Fin whale * ...............................................................................................................................
Humpback whale .....................................................................................................................
Minke whale ............................................................................................................................
Sei whale * ...............................................................................................................................
Sperm whale * .........................................................................................................................
Atlantic white-sided dolphin .....................................................................................................
Bottlenose dolphin a .................................................................................................................
Common dolphin .....................................................................................................................
Long-finned pilot whale b .........................................................................................................
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0.0043
0.0036
0.0022
0.018
0.0008
0.0008
0.0204
0.008
0.1467
0.001
23APN2
Maximum density month
December.
July.
June.
June.
November.
September.
June.
August.
September.
N/A.
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Federal Register / Vol. 89, No. 79 / Tuesday, April 23, 2024 / Notices
TABLE 8—MAXIMUM MEAN MONTHLY MARINE MAMMAL DENSITY ESTIMATES (ANIMALS PER km2) CONSIDERING A 10-km
BUFFER AROUND THE LIMITED INSTALLATION AREA—Continued
Species
Maximum mean density
Risso’s dolphin ........................................................................................................................
Harbor porpoise .......................................................................................................................
Seals (gray and harbor) c ........................................................................................................
0.0013
0.0713
0.1745
Maximum density month
December.
December.
May.
Note: * denotes species listed under the ESA.
a Density estimate represents the Northwestern Atlantic offshore stock of bottlenose dolphins.
b Only annual densities were available for the pilot whale guild.
c Gray and harbor seals represented as a guild.
For some species, PSO survey and
construction data for SNE (ESS Group,
2016; Vineyard Wind, 2018, 2019,
2023a–f) and mean group size data
compiled from the Atlantic Marine
Assessment Program for Protected
Species (AMAPPS) (Palka et al., 2017,
2021) indicate that the density-based
exposure estimates may be insufficient
to account for the number of individuals
of a species that may be encountered
during the planned activities. Hence,
consideration of local PSO and
AMAPPS data is required to ensure the
potential for take is adequately assessed.
In cases where the density-based
Level B harassment exposure estimate
for a species was less than the mean
group size-based exposure estimate, the
take request was increased to the mean
group size (in some cases multiple
groups were assumed) and rounded to
the nearest integer (table 9). For all
cetaceans, with the exception of
NARWs, Vineyard Wind used the mean
of the spring, summer, and fall
AMAPPS group sizes for each species
for the RI/MA WEA as shown in tables
2–2, 2–3, and 2–4 in Palka et al. (2021)
appendix III. These seasons were
selected as they would represent the
time period in which pile driving
activities would take place. Mean group
sizes for cetacean species derived from
RI/WEA AMAPPS data is shown below
in table 9. However, NARW seasonal
group sizes for the RI/MA WEA were
not available through the AMAPPS
dataset (Palka et al., 2021). Vineyard
Wind calculated mean group size for
NARWs using data from the northeast
(NE) shipboard surveys as provided in
table 6–5 of Palka et al. (2021). Vineyard
Wind calculated mean group size by
dividing the number of individual right
whales sighted (4) by the number of
right whale groups (2) (Palka et al.,
2021). The NE shipboard surveys were
conducted during summer (June 1
through August 31) and fall (September
1 through November 30) seasons (Palka
et al., 2021).
For seals, mean group size data was
also not available for the RI/MA WEA
through AMAPPS (Palka et al., 2021).
Vineyard Wind used 2010–2013
AMAPPS NE shipboard and aerial
survey at-sea seal sightings for gray and
harbor seals, as well as unidentified seal
sightings from spring, summer, and fall
to calculate mean group size for gray
and harbor seals (table 19–1, Palka et al.,
2017). To calculate mean group size for
seals, Vineyard Wind divided the total
number of animals sighted by the total
number of sightings. As the majority of
the sightings were not identified to
species, Vineyard Wind calculated a
single group size for all seal species
(table 9).
Additional detail regarding the
density and occurrence as well as the
assumptions and methodology used to
estimate take is included below and in
section 6.2 of the ITA application. Mean
group sizes used in take estimates,
where applicable, for all activities are
provided in table 9.
TABLE 9—MEAN MARINE MAMMAL GROUP SIZES USED IN TAKE ESTIMATE CALCULATIONS
Species
Mean group size
NARW * .....................................................................................................................
Fin whale * ................................................................................................................
Humpback whale ......................................................................................................
Minke whale ..............................................................................................................
Sei whale * ................................................................................................................
Sperm whale * ...........................................................................................................
Atlantic white-sided dolphin ......................................................................................
Bottlenose dolphin ....................................................................................................
Common dolphin ......................................................................................................
Long-finned pilot whale ............................................................................................
Risso’s dolphin .........................................................................................................
Harbor porpoise ........................................................................................................
Seals (gray and harbor) ...........................................................................................
2
1.2
1.2
1.4
1
2
21.7
11.7
30.8
12.3
1.8
2.9
1.4
Source
Table
Palka
Palka
Palka
Palka
Palka
Palka
Palka
Palka
Palka
Palka
Palka
Table
6–5 of Palka et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
et al., 2021.
19–1 of Palka et al., 2017.
ddrumheller on DSK120RN23PROD with NOTICES2
Note: * denotes species listed under the ESA.
Vineyard Wind also looked at PSO
survey data (June through October 2023)
in the LIA collected during Vineyard
Wind I construction activities and
calculated a daily sighting rate for
species to compare with density-based
take estimates and average group size
estimates from AMAPPS (table 9). The
number of animals of each species
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19:35 Apr 22, 2024
Jkt 262001
sighted from all survey vessels with
active PSOs was divided by the sum of
all PSO monitoring days (77 days) to
calculate the mean number of animals of
each species sighted (see table 11 in the
ITA application). However, for each
species, the PSO data-based exposure
estimate was less than the density-based
exposure estimate (see table 14 in the
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Fmt 4701
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ITA application) and, therefore, densitybased exposure estimates were not
adjusted according to PSO data-based
exposure estimates.
Here we present the amount of take
requested by Vineyard Wind and
proposed to be authorized. To estimate
take, Vineyard Wind use the pile
installation construction schedule
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23APN2
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Federal Register / Vol. 89, No. 79 / Tuesday, April 23, 2024 / Notices
shown in table 6, assuming 15 total days
of monopile installation. NMFS has
reviewed these methods to estimate take
and agrees with this approach. The
proposed take numbers in table 11,
appropriately consider SFV
measurements collected in 2023 and
represent the maximum amount of take
that is reasonably expected to occur.
TABLE 10—MODELED LEVEL A HARASSMENT AND LEVEL B HARASSMENT ACOUSTIC EXPOSURE ESTIMATES
Density-based exposure estimate
Species
Level A harassment
NARW * a ..........................................................................................................................................
Fin whale * .......................................................................................................................................
Humpback whale .............................................................................................................................
Minke whale .....................................................................................................................................
Sei whale * .......................................................................................................................................
Sperm whale * ..................................................................................................................................
Atlantic white-sided dolphin .............................................................................................................
Bottlenose dolphin ...........................................................................................................................
Common dolphin ..............................................................................................................................
Long-finned pilot whale ....................................................................................................................
Risso’s dolphin .................................................................................................................................
Harbor porpoise ...............................................................................................................................
Gray Seal .........................................................................................................................................
Harbor seal ......................................................................................................................................
Level B harassment
0.503
0.598
1.11
0.372
0.144
0
0
0
0
0
0
2.758
0
0.028
6.6
5.5
3.4
27.7
1.2
1.2
31.4
12.3
226
1.5
2
109.8
240.8
28.2
Note: * denotes species listed under the ESA.
a Although modeling shows a very low but non-zero exposure estimate for take by Level A harassment, mitigation measures will be applied to
ensure there is no take by Level A harassment of this species.
TABLE 11—PROPOSED AUTHORIZED TAKES
[by Level A harassment and Level B harassment]
Species
NMFS stock
abundance
Proposed take
by Level A
harassment
Proposed take
by Level B
harassment
338
6,802
1,396
21,968
6,292
4,349
93,233
62,851
172,974
39,215
35,215
95,543
27,300
61,336
0
1
2
1
1
0
0
0
0
0
0
3
0
1
7
6
4
28
2
2
32
13
462
13
2
110
241
29
NARW * a ..........................................................................................
Fin whale * ........................................................................................
Humpback whale .............................................................................
Minke whale .....................................................................................
Sei whale * .......................................................................................
Sperm whale * ..................................................................................
Atlantic white-sided dolphin .............................................................
Bottlenose dolphin ...........................................................................
Common dolphin b c ..........................................................................
Long-finned pilot whale b ..................................................................
Risso’s dolphin .................................................................................
Harbor porpoise ...............................................................................
Gray Seal .........................................................................................
Harbor seal ......................................................................................
Total
proposed
take
7
7
6
29
3
2
32
13
462
13
2
113
241
30
Percent of
stock
abundance
2.07
0.1
0.43
0.13
0.05
0.05
0.03
0.02
0.27
0.03
0.001
0.19
0.88
0.05
Note: * denotes species listed under the ESA.
a Although modeling shows a very low but non-zero exposure estimate for take by Level A harassment, mitigation measures will be applied to
ensure there is no take by Level A harassment of this species.
b Proposed take by Level B harassment adjusted according to mean group size.
c Proposed take by Level B harassment is based upon the assumption that one group of common dolphins (30.8 dolphins; see table 9) would
be encountered per each of the 15 days of pile driving.
ddrumheller on DSK120RN23PROD with NOTICES2
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 the activity, and
other means of effecting the least
practicable impact on the species or
stock and its habitat, paying particular
attention to rookeries, mating grounds,
and areas of similar significance, and on
the availability of the species or stock
for taking for certain subsistence uses
(latter not applicable for this action).
NMFS regulations require applicants for
incidental take authorizations to include
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information about the availability and
feasibility (economic and technological)
of equipment, methods, and manner of
conducting the activity or other means
of effecting the least practicable adverse
impact upon the affected species or
stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or
may not be appropriate to effect the
least practicable adverse impact on
species or stocks and their habitat, as
well as subsistence uses where
applicable, NMFS considers two
primary factors:
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(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
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ddrumheller on DSK120RN23PROD with NOTICES2
(2) The practicability of the measures
for applicant implementation, which
may consider such things as cost and
impact on operations.
The mitigation strategies described
below are consistent with those required
and successfully implemented under
previous incidental take authorizations
issued in association with in-water
construction activities (e.g., soft-start,
establishing shutdown zones).
Additional measures have also been
incorporated to account for the fact that
the proposed construction activities
would occur offshore. In addition,
several measures proposed for this IHA
(i.e., seasonal restrictions, vessel strike
avoidance, and clearance and shutdown
zones) are more rigorous than measures
previously incorporated into the 2023
IHA.
Generally speaking, the mitigation
measures considered and proposed to be
required here fall into three categories:
(1) temporal (seasonal and daily) work
restrictions, (2) real-time measures
(shutdown, clearance, and vessel strike
avoidance), and (3) noise attenuation/
reduction measures. Seasonal work
restrictions are designed to avoid or
minimize operations when marine
mammals are concentrated or engaged
in behaviors that make them more
susceptible or make impacts more
likely, in order to reduce both the
number and severity of potential takes,
and are effective in reducing both
chronic (longer-term) and acute effects.
Real-time measures, such as
implementation of shutdown and
clearance zones, as well as vessel strike
avoidance measures, are intended to
reduce the probability or severity of
harassment by taking steps in real time
once a higher-risk scenario is identified
(e.g., once animals are detected within
an impact zone). Noise attenuation
measures, such as bubble curtains, are
intended to reduce the noise at the
source, which reduces both acute
impacts, as well as the contribution to
aggregate and cumulative noise that may
result in longer-term chronic impacts.
Below, we also describe the required
training, coordination, and vessel strike
avoidance measures that apply to
foundation installation and vessel use.
Training and Coordination
NMFS requires all Vineyard Wind’s
employees and contractors conducting
activities on the water, including, but
not limited to, all vessel captains and
crew, to be trained in marine mammal
detection and identification,
communication protocols, and all
required measures to minimize impacts
on marine mammals and support
Vineyard Wind’s compliance with the
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IHA, if issued. Additionally, all relevant
personnel and the marine mammal
species monitoring team(s) are required
to participate in joint, onboard briefings
prior to the beginning of project
activities. The briefing must be repeated
whenever new relevant personnel (e.g.,
new PSOs, construction contractors,
relevant crew) join the project before
work commences. During this training,
Vineyard Wind is required to instruct
all project personnel regarding the
authority of the marine mammal
monitoring team(s). For example, pile
driving personnel are required to
immediately comply with any call for a
delay or shut down by the Lead PSO.
Any disagreement between the Lead
PSO and the project personnel must
only be discussed after delay or
shutdown has occurred. In particular,
all captains and vessel crew must be
trained in marine mammal detection
and vessel strike avoidance measures to
ensure marine mammals are not struck
by any project or project-related vessel.
Prior to the start of in-water
construction activities, Vineyard Wind
would conduct training for construction
and vessel personnel and the marine
mammal monitoring team (PSO and
PAM operators) to explain
responsibilities, communication
procedures, marine mammal detection
and identification, mitigation,
monitoring, and reporting requirements,
safety and operational procedures, and
authorities of the marine mammal
monitoring team(s). A description of the
training program must be provided to
NMFS at least 60 days prior to the
initial training before in-water activities
begin. Vineyard Wind would provide
confirmation of all required training
documented on a training course log
sheet and reported to NMFS OPR prior
to initiating project activities.
NARW Awareness Monitoring
Vineyard Wind would be required to
use available sources of information on
NARW presence, including daily
monitoring of the Right Whale Sightings
Advisory System, U.S. Coast Guard very
high-frequency (VHF) Channel 16,
WhaleAlert, and the PAM system
throughout each day to receive
notifications of any Slow Zones (i.e.,
Dynamic management areas (DMAs)
and/or acoustically-triggered slow
zones) to provide situational awareness
for vessel operators, PSOs, and PAM
operators. The marine mammal
monitoring team must monitor these
systems at least every 4 hours.
Maintaining daily awareness and
coordination affords increased
protection of NARWs by understanding
NARW presence in the area through
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31043
ongoing visual and passive acoustic
monitoring efforts and opportunities
(outside of Vineyard Wind’s efforts),
and allows for planning of construction
activities, when practicable, to
minimize potential impacts on NARWs.
Vessel Strike Avoidance Measures
This proposed IHA contains
numerous vessel strike avoidance
measures that reduce the risk that a
vessel and marine mammal could
collide. While the likelihood of a vessel
strike is generally low, they are one of
the most common ways that marine
mammals are seriously injured or killed
by human activities. Therefore,
enhanced mitigation and monitoring
measures are required to avoid vessel
strikes, to the extent practicable. While
many of these measures are proactive,
intending to avoid the heavy use of
vessels during times when marine
mammals of particular concern may be
in the area, several are reactive and
occur when a project personnel sights a
marine mammal. Vineyard Wind would
be required to comply with these
measures except under circumstances
when doing so would create an
imminent and serious threat to a person
or vessel or to the extent that a vessel
is unable to maneuver and, because of
the inability to maneuver, the vessel
cannot comply.
While underway, Vineyard Wind’s
personnel would be required to monitor
for and maintain a minimum separation
distance from marine mammals and
operate vessels in a manner that reduces
the potential for vessel strike.
Regardless of the vessel’s size or speed,
all vessel operators, crews, and
dedicated visual observers (i.e., PSO or
trained crew member) must maintain a
vigilant watch for all marine mammals
and slow down, stop their vessel, or
alter course (as appropriate) to avoid
striking any marine mammal. The
dedicated visual observer, required on
all transiting vessels and equipped with
suitable monitoring technology (e.g.,
binoculars, night vision devices), must
be located at an appropriate vantage
point for ensuring vessels are
maintaining required vessel separation
distances from marine mammals (e.g.,
500 m from NARWs).
All of the project-related vessels
would be required to comply with
existing NMFS vessel speed restrictions
for NARWs, and additional speed and
approach restrictions measures within
this IHA. All vessels must reduce speed
to 10 kn or less when traveling in a
DMA, Slow Zone or when a NARW is
observed or acoustically detected.
Reducing vessel speed is one of the
most effective, feasible options available
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Federal Register / Vol. 89, No. 79 / Tuesday, April 23, 2024 / Notices
to reduce the likelihood of and effects
from a vessel strike. Numerous studies
have indicated that slowing the speed of
vessels reduces the risk of lethal vessel
collisions, particularly in areas where
right whales are abundant and vessel
traffic is common and otherwise
traveling at high speeds (Vanderlaan
and Taggart, 2007; Conn and Silber,
2013; Van der Hoop et al., 2014; Martin
et al., 2015; Crum et al., 2019).
When NMFS vessel speed restrictions
are not in effect and a vessel is traveling
at greater than 10 kn (18.5 km/hr), in
addition to the required dedicated
visual observer, Vineyard Wind would
be required to monitor the crew transfer
vessel transit corridor (the path crew
transfer vessels take from port to any
work area) in real-time with PAM prior
to and during transits.
All project vessels, regardless of size,
must maintain the following minimum
separation zones: 500 m from NARWs;
100 m from sperm whales and nonNARW baleen whales; and 50 m from
all delphinid cetaceans and pinnipeds
(an exception is made for those species
that approach the vessel such as bowriding dolphins) (table 12). All
reasonable steps must be taken to not
violate minimum separation distances.
If any of these species are sighted within
their respective minimum separation
zone, the underway vessel must turn
away from the animal and shift its
engine to neutral (if safe to do so) and
the engines must not be engaged until
the animal(s) have been observed to be
outside of the vessel’s path and beyond
the respective minimum separation
zone. If a NARW is observed at any
distance by any project personnel or
acoustically detected, project vessels
must reduce speeds to 10 kn and turn
away from the animal. Additionally, in
the event that any project-related vessel,
regardless of size, observes any large
whale (other than a NARW) within 500
m of an underway vessel, the vessel is
required to immediately reduce speeds
to 10 kn or less and turn away from the
animal.
TABLE 12—VESSEL STRIKE AVOIDANCE SEPARATION ZONES
Vessel separation zone
(m)
Marine mammal species
NARW ..................................................................................................................................................................................
Other ESA-listed species and non-NARW large whales ....................................................................................................
Other marine mammals a .....................................................................................................................................................
a With
the exception of seals and delphinid(s) from the genera Delphinus, Lagenorhynchus, Stenella, or Tursiops, as described below.
Any marine mammal observed by
project personnel must be immediately
communicated to any on-duty PSOs,
PAM operator(s), and all vessel
captains. Any NARW or large whale
observation or acoustic detection by
PSOs or PAM operators must be
conveyed to all vessel captains. All
vessels would be equipped with an AIS
and Vineyard Wind must report all
Maritime Mobile Service Identity
(MMSI) numbers to NMFS OPR prior to
initiating in-water activities. Vineyard
Wind has submitted an updated NMFSapproved NARW Vessel Strike
Avoidance Plan, which NMFS is
reviewing for alignment with the
measures proposed herein.
Given the extensive vessel strike
avoidance measures coupled with the
limited amount of work associated with
the project, NMFS has determined that
Vineyard Wind’s compliance with these
proposed measures would reduce the
likelihood of vessel strike to
discountable levels.
Seasonal and Daily Restrictions
ddrumheller on DSK120RN23PROD with NOTICES2
500
100
50
Temporal restrictions in places where
marine mammals are concentrated,
engaged in biologically important
behaviors, and/or present in sensitive
life stages are effective measures for
reducing the magnitude and severity of
human impacts. The temporal
restrictions proposed here are built
around NARW protection. Based upon
the best scientific information available
(Roberts et al., 2023), the highest
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densities of NARWs in the specified
geographic region are expected during
the months of January through May,
with an increase in density starting in
December. However, NARWs may be
present in the specified geographic
region throughout the year.
NMFS is proposing to require
seasonal work restrictions to minimize
risk of noise exposure to the NARWs
incidental to pile driving activities to
the extent practicable. These seasonal
work restrictions are expected to reduce
the number of takes of NARWs and
further reduce vessel strike risk. These
seasonal restrictions also afford
protection to other marine mammals
that are known to use the LIA with
greater frequency during winter months,
including other baleen whales. As
described previously, no impact pile
driving activities may occur January 1
through May 31, and pile driving in
December must be avoided to the
maximum extent practicable and only if
enhanced monitoring is undertaken and
NMFS approves.
Vineyard Wind proposed to install no
more than one pile per day and only
initiate impact pile driving during
daylight hours. Vineyard Wind would
not be able to initiate pile driving later
than 1.5 hours after civil sunset or
continue pile driving after or 1 hour
before civil sunrise. However, if
Vineyard Wind determines that they
must initiate pile driving after the
aforementioned time frame, they must
submit a sufficient nighttime pile
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driving plan for NMFS review and
approval to do so. A sufficient nighttime
pile driving plan would demonstrate
that proposed detection systems would
be capable of detecting marine
mammals, particularly large whales, at
distances necessary to ensure mitigation
measures are effective.
Noise Attenuation Systems
Vineyard Wind would be required to
employ noise abatement systems (NAS),
also known as noise attenuation
systems, during all foundation
installation activities to reduce the
sound pressure levels that are
transmitted through the water in an
effort to reduce acoustic ranges to the
Level A harassment and Level B
harassment acoustic thresholds and
minimize, to the extent practicable, any
acoustic impacts resulting from these
activities. Vineyard Wind proposes and
NMFS is proposing to require Vineyard
Wind to use a double bubble curtain
(DBBC) and Hydro Sound damper (HSD)
in addition to an enhanced big bubble
curtain (BBC) maintenance schedule.
The refined NAS design (DBBC + HSD
+ enhanced bubble curtain (BC)
maintenance schedule) used during the
2023 construction activities would be
used on the 15 remaining piles to
minimize noise levels. A single bubble
curtain, alone or in combination with
another NAS device, may not be used
for pile driving as received SFV data
reveals this approach is unlikely to
attenuate sound sufficiently to be
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consistent with the target sound
reduction of 6 dB, in which the
expected ranges to the Level A
harassment and Level B harassment
isopleths are based upon.
Two categories of NAS exist: primary
and secondary. A primary NAS would
be used to reduce the level of noise
produced by foundation installation
activities at the source, typically
through adjustments to the equipment
(e.g., hammer strike parameters).
Primary NAS are still evolving and will
be considered for use during mitigation
efforts when the NAS has been
demonstrated as effective in commercial
projects. However, as primary NAS are
not fully effective at eliminating noise,
a secondary NAS would be employed.
The secondary NAS is a device or group
of devices that would reduce noise as it
is transmitted through the water away
from the pile, typically through a
physical barrier that would reflect or
absorb sound waves and therefore
reduce the distance the higher energy
sound propagates through the water
column. Together, these systems must
reduce noise levels to those not
exceeding expected ranges to Level A
harassment and Level B harassment
isopleths corresponding to those
modeled assuming 6-dB sound
attenuation, pending results of SFV (see
Sound Field Verification section below).
Noise abatement systems, such as
bubble curtains, are used to decrease the
sound levels radiated from a source.
Bubbles create a local impedance
change that acts as a barrier to sound
transmission. The size of the bubbles
determines their effective frequency
band, with larger bubbles needed for
lower frequencies. There are a variety of
bubble curtain systems, confined or
unconfined bubbles, and some with
encapsulated bubbles or panels.
Attenuation levels also vary by type of
system, frequency band, and location.
Small bubble curtains have been
measured to reduce sound levels, but
effective attenuation is highly
dependent on depth of water, current,
and configuration and operation of the
curtain (Austin et al., 2016; Koschinski
and Lu¨demann, 2013). Bubble curtains
vary in terms of the sizes of the bubbles;
those with larger bubbles tend to
perform a bit better and more reliably,
particularly when deployed with two
separate rings (Bellmann, 2014;
Koschinski and Lu¨demann, 2013; Nehls
et al., 2016). Encapsulated bubble
systems (i.e., HSDs) can be effective
within their targeted frequency ranges
(e.g., 100–800 Hz) and when used in
conjunction with a bubble curtain
appear to create the greatest attenuation.
The literature presents a wide array of
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observed attenuation results for bubble
curtains. The variability in attenuation
levels is the result of variation in design
as well as differences in site conditions
and difficulty in properly installing and
operating in-water attenuation devices.
For example, Da¨hne et al. (2017)
found that single bubble curtains that
reduce sound levels by 7 to 10 dB
reduced the overall sound level by
approximately 12 dB when combined as
a double bubble curtain for 6-m steel
monopiles in the North Sea. During
installation of monopiles (consisting of
approximately 8-m in diameter) for
more than 150 WTGs in comparable
water depths (>25 m) and conditions in
Europe indicate that attenuation of 10
dB is readily achieved (Bellmann, 2019;
Bellmann et al., 2020) using single BBCs
for noise attenuation. When a DBBC is
used (noting a single BC is not allowed),
Vineyard Wind would be required to
maintain numerous operational
performance standards, including the
enhanced BBC maintenance protocol
(Vineyard Wind Enhanced BBC
Technical Memo, 2023). These
standards are defined in the proposed
IHA and include, but are not limited to,
a requirement that construction
contractors train personnel in the
proposed balancing of airflow to the
bubble ring; and a requirement that
Vineyard Wind submit a performance
test and maintenance report to NMFS
within 72 hours following the
performance test. Corrections to the
attenuation device to meet regulatory
requirements must occur prior to use
during foundation installation activities.
In addition, a full maintenance check
(e.g., manually clearing holes) must
occur prior to each pile being installed.
The HSD system Vineyard Wind
proposes to use would be employed, in
coordination with the DBBC, as a nearfield attenuation device close to the
monopiles (Ku¨sel et al., 2024). Vineyard
Wind has also proposed to follow a
DBBC enhanced maintenance protocol,
which was used during the 2023
Vineyard Wind pile installation
activities. The DBBC enhanced
maintenance protocol includes an
adjustment from typical bubble curtain
operations to drill hoses after every
deployment to maximize performance
in siltier sediments which are present in
the Lease Area. The DBBC enhanced
maintenance protocol also includes
DBBC hose inspection and clearance,
pressure testing of DBBC hoses, visual
inspection of DBBC performance, and
minimizing disturbance of the DBBC
hoses on the seafloor.
Should SFV identify that distances to
NMFS harassment isopleths are louder
than expected, Vineyard Wind would be
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required to adjust the NAS, or conduct
other measures to reduce noise levels,
such that distances to thresholds are not
exceeded.
Clearance and Shutdown Zones
NMFS is proposing to require the
establishment of both clearance and
shutdown zones during impact pile
driving. The purpose of ‘‘clearance’’ of
a particular zone is to minimize
potential instances of auditory injury
and more severe behavioral
disturbances by delaying the
commencement of an activity if marine
mammals are near the activity. The
purpose of a ‘‘shutdown’’ is to prevent
a specific acute impact, such as auditory
injury or severe behavioral disturbance
of sensitive species, by halting the
activity. Due to the increased density of
NARWs during the months of November
and December, more stringent clearance
and shutdown mitigation measures are
proposed for these months.
All relevant clearance and shutdown
zones during project activities would be
monitored by NMFS-approved PSOs
and PAM operators. PAM would be
conducted at least 24 hours in advance
of any pile driving activities. At least
one PAM operator would review data
from at least 24 hours prior to
foundation installation (to increase
situational awareness) and actively
monitor hydrophones for 60 minutes
prior to commencement of these
activities. Any sighting or acoustic
detection of a NARW would trigger a
delay to commencing pile driving and
shutdown.
Prior to the start of pile driving
activities, Vineyard Wind would be
required to ensure designated areas (i.e.,
clearance zones, table 13) are clear of
marine mammals before commencing
activities to minimize the potential for
and degree of harassment. Three onduty PSOs would monitor from the pile
driving support vessel and two PSO
support vessels, each with three PSOs
on board, before (60 minutes), during,
and after (30 minutes) all pile driving.
PSOs must visually monitor clearance
zones for marine mammals for a
minimum of 60 minutes, where the zone
must be confirmed free of marine
mammals at least 30 minutes directly
prior to commencing these activities.
The minimum visibility zone, defined
as the area over which PSOs must be
able to visually detect marine mammals,
would extend 4,000 m for monopile
installation from the pile being driven
(table 13), and must be visible for 60
minutes. The minimum visibility zone
corresponds to the modeled Level A
harassment distance for low-frequency
cetaceans plus twenty percent, and
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rounded up to the nearest 0.5 km. The
minimum visibility zone must be
visually cleared of marine mammals. If
this zone is obscured to the degree that
effective monitoring cannot occur, pile
driving must be delayed. Minimum
visibility zone and clearance zones are
defined and provided in table 13 for all
species.
From December 1 to 31, a vesselbased survey would be used to confirm
the clearance zone (10 km PAM
clearance zone (6.2 mi); table 13) is clear
of NARWs prior to pile driving. The
survey would be supported by a team of
nine PSOs coordinating visual
monitoring across two PSO support
vessels and the pile driving platform.
The two PSO support vessels, each with
three active on-duty PSOs, would be
positioned at the same distance on
either side of the pile driving vessel.
Each PSO support vessel would transit
along a steady course along parallel
track lines in opposite directions. Each
transect line would be surveyed at a
similar speed, not to exceed 10 kn, and
would last for approximately 30
minutes to 1 hour. If a NARW is sighted
at any distance during the vessel-based
survey, pile driving would be delayed
until the following day unless an
additional vessel-based survey with
additional transects are conducted to
determine the clearance zone is clear of
NARWs. Further details on PSO support
vessel monitoring efforts are described
in the Vineyard Wind application
section 11, table 17.
Once pile driving activity begins, any
marine mammal entering their
respective shutdown zone would trigger
the activity to cease. In the case of pile
driving, the shutdown requirement may
be waived if is not practicable due to
imminent risk of injury or loss of life to
an individual or risk of damage to a
vessel that creates risk of injury or loss
of life for individuals, or if the lead
engineer determines there is pile refusal
or pile instability.
In situations when shutdown is called
for, but Vineyard Wind determines
shutdown is not practicable due to
aforementioned emergency reasons,
reduced hammer energy must be
implemented when the lead engineer
determines it is practicable.
Specifically, pile refusal or pile
instability could result in the inability
to shut down pile driving immediately.
Pile refusal occurs when the pile driving
sensors indicate the pile is approaching
refusal, and a shut-down would lead to
a stuck pile which then poses an
imminent risk of injury or loss of life to
an individual, or risk of damage to a
vessel that creates risk for individuals.
Pile instability occurs when the pile is
unstable and unable to stay standing if
the piling vessel were to ‘‘let go.’’
During these periods of instability, the
lead engineer may determine a shutdown is not feasible because the shutdown combined with impending
weather conditions may require the
piling vessel to ‘‘let go’’ which then
poses an imminent risk of injury or loss
of life to an individual, or risk of
damage to a vessel that creates risk for
individuals. Vineyard Wind must
document and report to NMFS all cases
where the emergency exemption is
taken.
After shutdown, impact pile driving
may be reinitiated once all clearance
zones are clear of marine mammals for
the minimum species-specific periods,
or, if required to maintain pile stability,
impact pile driving may be reinitiated
but must be used to maintain stability.
From June 1 to October 31, if pile
driving has been shut down due to the
presence of a NARW, pile driving must
not restart until the NARW has not been
visually or acoustically detected for 30
minutes. Upon re-starting pile driving,
soft-start protocols must be followed if
pile driving has ceased for 30 minutes
or longer. From November 1 to
December 31, if pile driving has been
shut down or delayed due to the
presence of three or more NARWs, pile
driving will be postponed until the next
day. Shutdown zones vary by species
and are shown in table 13 below.
TABLE 13—MINIMUM VISIBILITY, CLEARANCE, SHUTDOWN, AND LEVEL B HARASSMENT ZONES, IN METERS (m), DURING
IMPACT PILE DRIVING
Other
mysticetes/
sperm whales
(m) b
NARWs a
Monitoring zones
Minimum Visibility Zone c ............................
Visual Clearance Zone ...............................
PAM Clearance Zone .................................
Visual Shutdown Zone ...............................
PAM Monitoring Zone d ..............................
Pinnipeds
(m) b
4,000
Any distance from PSOs ............................
10,000 .........................................................
Any distance ...............................................
10,000 .........................................................
Distance to Level B Harassment Threshold
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Pilot whales,
harbor porpoises,
and delphinids
(m) b
500
500
500
500
160
160
160
160
160
160
160
160
5,720
a From December 1 to December 31, vessel based surveys using two PSO support vessels would confirm that the 10-km (6.2-mi) PAM clearance zone is clear of NARWs. If three or more NARWs are sighted in November or December, pile driving will be delayed for 24 hours.
b Pile driving may commence when either the marine mammal has voluntarily left the respective clearance zone and has been visually confirmed beyond that clearance zone, or when 30 minutes (NARWs (June-October), other non-NARW mysticetes, sperm whales, pilot whales,
Risso’s dolphins) or 15 minutes (all other delphinids and pinnipeds)have elapsed without re-detection.
c Minimum visibility zone is the minimum distance that must be visible prior to initiating pile driving, as determined by the lead PSO. The minimum visibility zone corresponds to the Level A harassment distance for low-frequency cetaceans plus twenty percent, and rounded up to the
nearest 0.5 km
d The PAM system must be capable of detecting NARWs at 10 km during pile driving. The system should also be designed to detect other marine mammals to the maximum extent practicable; however, it is not required these other species be detected out to 10 km given higher frequency calls and echolocation clicks are not typically detectable at large distances.
For any other in-water construction
heavy machinery activities (e.g.,
trenching, cable laying, etc.), if a marine
mammal is on a path towards or comes
within 10 m (32.8 ft) of equipment,
Vineyard Wind would be required to
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delay or cease operations until the
marine mammal has moved more than
10 m on a path away from the activity
to avoid direct interaction with
equipment.
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Soft-start
The use of a soft-start procedure is
believed to provide additional
protection to marine mammals by
warning them or providing them with a
chance to leave the area prior to the
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Proposed Monitoring and Reporting
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
activity; or (4) biological or behavioral
context of exposure (e.g., age, calving or
feeding areas);
• Individual marine mammal
responses (behavioral or physiological)
to acoustic stressors (acute, chronic, or
cumulative), other stressors, or
cumulative impacts from multiple
stressors;
• How anticipated responses to
stressors impact either: (1) long-term
fitness and survival of individual
marine mammals; or (2) populations,
species, or stocks;
• Effects on marine mammal habitat
(e.g., marine mammal prey species,
acoustic habitat, or other important
physical components of marine
mammal habitat); and,
• Mitigation and monitoring
effectiveness.
Separately, monitoring is also
regularly used to support mitigation
implementation, which is referred to as
mitigation monitoring, and monitoring
plans typically include measures that
both support mitigation implementation
and increase our understanding of the
impacts of the activity on marine
mammals.
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.
NMFS’ MMPA implementing
regulations at 50 CFR 216.104(a)(13)
indicate that requests for authorization
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 while conducting
the activities. 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
Protected Species Observer and PAM
Operator Requirements
PSOs are trained professionals who
are tasked with visual monitoring for
marine mammals during pile driving
activities. The primary purpose of a PSO
is to carry out the monitoring, collect
data, and, when appropriate, call for the
implementation of mitigation measures.
Visual monitoring by NMFS-approved
PSOs would be conducted at a
minimum of 60 minutes before, during,
and 30 minutes after all proposed
impact pile driving activities. In
addition to visual observations, NMFS
would require Vineyard Wind to
conduct PAM using NMFS-approved
PAM operators during impact pile
driving and vessel transit. PAM would
also be conducted for 24 hours in
advance and during impact pile driving
activities. Visual observations and
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hammer operating at full capacity. Softstart typically involves initiating
hammer operation at a reduced energy
level (relative to full operating capacity)
followed by a waiting period. Vineyard
Wind would be required to utilize a
soft-start protocol for impact pile
driving of monopiles by performing four
to six single hammer strikes at less than
40 percent of the maximum hammer
energy followed by at least a 1-minute
delay before the subsequent hammer
strikes. This process shall be conducted
at least tjree times (e.g., four to six single
strikes, delay, four to six single strikes,
delay, four to six single strikes, delay)
for a minimum of 20 minutes. NMFS
notes that it is difficult to specify a
reduction in energy for any given
hammer because of variation across
drivers and installation conditions.
Vineyard Wind will reduce energy
based on consideration of site-specific
soil properties and other relevant
operational considerations.
Soft start would be required at the
beginning of each day’s activity and at
any time following a cessation of
activity of 30 minutes or longer. Prior to
soft-start, the operator must receive
confirmation from the PSO that the
clearance zone is clear of any marine
mammals.
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 of 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.
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acoustic detections would be used to
support the mitigation measures (e.g.,
clearance zones). To increase
understanding of the impacts of the
activity on marine mammals, PSOs must
record all incidents of marine mammal
occurrence at any distance from the
piling locations. PSOs would document
all behaviors and behavioral changes, in
concert with distance from an acoustic
source.
NMFS proposes to require PAM
conducted by NMFS-approved PAM
operators, following a standardized
measurement, processing methods,
reporting metrics, and metadata
standards for offshore wind. PAM
alongside visual data collection is
valuable to provide the most accurate
record of species presence as possible,
and these two monitoring methods are
well understood to provide best results
when combined together (e.g., Barlow
and Taylor, 2005; Clark et al., 2010;
Gerrodette et al., 2011; Van Parijs et al.,
2021). Acoustic monitoring (in addition
to visual monitoring) increases the
likelihood of detecting marine mammals
within the shutdown and clearance
zones of project activities, which when
applied in combination with required
shutdowns helps to further reduce the
risk of marine mammals being exposed
to sound levels that could otherwise
result in acoustic injury or more intense
behavioral harassment.
The exact configuration and number
of PAM systems depends on the size of
the zone(s) being monitored, the amount
of noise expected in the area, and the
characteristics of the signals being
monitored. More closely spaced
hydrophones would allow for more
directionality, and perhaps, range to the
vocalizing marine mammals; although,
this approach would add additional
costs and greater levels of complexity to
the project. Larger baleen cetacean
species (i.e., mysticetes), which produce
loud and lower-frequency vocalizations,
may be able to be heard with fewer
hydrophones spaced at greater
distances. However, smaller cetaceans
(such as mid-frequency delphinids or
odontocetes) may necessitate more
hydrophones and to be spaced closer
together given the shorter range of the
shorter, mid-frequency acoustic signals
(e.g., whistles and echolocation clicks).
The configuration for collecting the
required marine mammal data will be
based upon the acoustic data acquisition
methods used during the 2023 Vineyard
Wind construction campaign (Ku¨sel et
al., 2024).
NMFS does not formally administer
any PSO or PAM operator training
program or endorse specific providers
but would approve PSOs and PAM
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operators that have successfully
completed courses that meet the
curriculum and trainer requirements.
All PSOs and PAM operators must have
successfully attained a bachelor’s degree
from an accredited college or university
with a major in one of the natural
sciences, a minimum of 30 semester
hours or equivalent in the biological
sciences, and at least one undergraduate
course in math or statistics. The
educational requirements may be
waived if the PSO or PAM operator has
acquired the relevant skills through
alternate experience. Requests for such
a waiver shall be submitted to NMFS
and must include written justification.
Alternate experience that may be
considered includes, but is not limited
to: (1) secondary education and/or
experience comparable to PSO and/or
PAM operator duties; (2) previous work
experience conducting academic,
commercial, or government-sponsored
marine mammal surveys; and (3)
previous work experience as a PSO/
PAM operator (PSOs/PAM operators
must be in good standing and
demonstrate good performance of PSO/
PAM operator duties). All PSOs and
PAM operators must have successfully
completed a relevant training course
within the last 5 years, including
obtaining a certificate of course
completion that would be submitted to
NMFS.
For prospective PSOs and PAM
operators not previously approved, or
for PSOs and PAM operators whose
approval is not current, NMFS must
review and approve PSO and PAM
operator qualifications. Vineyard Wind
would be required to submit PSO and
PAM operator resumes for approval at
least 60 days prior to PSO and PAM
operator use. Resumes must include
information related to relevant
education, experience, and training,
including dates, duration, location, and
description of prior PSO and/or PAM
experience, and be accompanied by
relevant documentation of successful
completion of necessary training.
Should Vineyard Wind require
additional PSOs or PAM operators
throughout the project, Vineyard Wind
must submit a subsequent list of preapproved PSOs and PAM operators to
NMFS at least 15 days prior to planned
use of that PSO or PAM operator. PSOs
and PAM operators must have previous
experience observing marine mammals
and must have the ability to work with
all required and relevant software and
equipment.
PAM operators are responsible for
obtaining NMFS approval. To be
approved as a PAM operator, the person
must meet the following qualifications:
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The PAM operator must demonstrate
that they have prior experience with
real-time acoustic detection systems
and/or have completed specialized
training for operating PAM systems and
detecting and identifying Atlantic
Ocean marine mammal sounds, in
particular, NARW sounds, humpback
whale sounds, and how to deconflict
them from similar NARW sounds, and
other co-occurring species’ sounds in
the area including sperm whales. The
PAM operator must be able to
distinguish between whether a marine
mammal or other species sound is
detected, possibly detected, or not
detected, and similar terminology must
be used across companies/projects.
Where localization of sounds or
deriving bearings and distance are
possible, the PAM operators need to
have demonstrated experience in using
this technique. PAM operators must be
independent observers (i.e., not
construction personnel), and must
demonstrate experience with relevant
acoustic software and equipment. PAM
operators must have the qualifications
and relevant experience/training to
safely deploy and retrieve equipment
and program the software, as necessary.
PAM operators must be able to test
software and hardware functionality
prior to operation, and PAM operators
must have evaluated their acoustic
detection software using the PAM
Atlantic baleen whale annotated data set
available at National Centers for
Environmental Information (NCEI) and
provide evaluation/performance metric.
PAM operators must also be able to
review and classify acoustic detections
in real-time (prioritizing NARWs and
noting detection of other cetaceans)
during the real-time monitoring periods.
NMFS may approve PSOs and PAM
operators as conditional or
unconditional. An unconditionally
approved PSO or PAM operator is one
who has completed training within the
last 5 years and attained the necessary
experience (i.e., demonstrate experience
with monitoring for marine mammals at
clearance and shutdown zone sizes
similar to those produced during the
respective activity). A conditionally
approved PSO or PAM operator may be
one who has completed training in the
last 5 years but has not yet attained the
requisite field experience.
Conditionally approved PSOs and
PAM operators would be paired with an
unconditionally approved PSO (or PAM
operator, as appropriate) to ensure that
the quality of marine mammal
observations and data recording is kept
consistent. Additionally, impact pile
driving activities would require PSOs
and/or PAM operator monitoring to
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have a lead on duty. The visual PSO
field team, in conjunction with the PAM
team (i.e., marine mammal monitoring
team) would have a lead member
(designated as the ‘‘Lead PSO’’ or ‘‘Lead
PAM operator’’) who would be required
to meet the unconditional approval
standard. Lead PSO or PAM operators
must also have a minimum of 90 days
in a northwestern Atlantic Ocean
offshore environment performing the
role (either visual or acoustic), with the
conclusion of the most recent relevant
experience not more than 18 months
previous. A PSO may be trained and/or
experienced as both a PSO and PAM
operator and may perform either duty,
pursuant to scheduling requirements
(and vice versa).
PSOs must have visual acuity in both
eyes (with correction of vision being
permissible) sufficient enough to
discern moving targets on the water’s
surface with the ability to estimate the
target size and distance (binocular use is
allowable), ability to conduct field
observations and collect data according
to the assigned protocols, and the ability
to communicate orally, by radio, or inperson, with project personnel to
provide real-time information on marine
mammals observed in the area. All PSOs
must be trained in northwestern
Atlantic Ocean marine mammal
identification and behaviors and must
be able to conduct field observations
and collect data according to assigned
protocols. Additionally, PSOs must
have the ability to work with all
required and relevant software and
equipment necessary during
observations.
Vineyard Wind must work with the
selected third-party PSO and PAM
operator provider to ensure PSOs and
PAM operators have all equipment
(including backup equipment) needed
to adequately perform necessary tasks.
For PSOs, this includes, but is not
limited to, accurate determination of
distance and bearing to observed marine
mammals, and to ensure that PSOs are
capable of calibrating equipment as
necessary for accurate distance
estimates and species identification.
PSO equipment, at a minimum, shall
include:
• At least one thermal (infrared)
imaging device suited for the marine
environment;
• Reticle binoculars (e.g., 7 × 50) of
appropriate quality (at least one per
PSO, plus backups);
• Global positioning units (GPS) (at
least one plus backups);
• Digital cameras with a telephoto
lens that is at least 300 mm or
equivalent on a full-frame single lens
reflex (SLR) (at least one plus backups).
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The camera or lens should also have an
image stabilization system;
• Equipment necessary for accurate
measurement of distances to marine
mammal;
• Compasses (at least one plus
backups);
• Means of communication among
vessel crew and PSOs; and,
• Any other tools deemed necessary
to adequately and effectively perform
PSO tasks.
At least two PSOs on the pile driving
vessel must be equipped with functional
Big Eye binoculars (e.g., 25 × 150; 2.7
view angle; individual ocular focus;
height control), Big Eye binocular would
be pedestal mounted on the deck at the
best vantage point that provides for
optimal sea surface observation and
PSO safety. PAM operators must have
the appropriate equipment (i.e., a
computer station equipped with a data
collection software system available
wherever they are stationed) and use a
NMFS-approved PAM system to
conduct monitoring. The equipment
specified above may be provided by an
individual PSO, the third-party PSO
provider, or the operator, but Vineyard
Wind is responsible for ensuring PSOs
have the proper equipment required to
perform the duties specified in the IHA.
Reference materials must be available
aboard all project vessels for
identification of protected species.
PSOs and PAM operators would not
be permitted to exceed 4 consecutive
watch hours on duty at any time, would
have a 2-hour (minimum) break between
watches, and would not exceed a
combined watch schedule of more than
12 hours in a 24-hour period. If the
schedule includes PSOs and PAM
operators on-duty for 2-hour shifts, a
minimum 1-hour break between
watches would be allowed.
The PSOs would be responsible for
monitoring the waters surrounding the
pile driving site to the farthest extent
permitted by sighting conditions,
including pre-start clearance and
shutdown zones, prior to, during, and
following foundation installation
activities. Monitoring must be done
while free from distractions and in a
consistent, systematic, and diligent
manner. If PSOs cannot visually
monitor the minimum visibility zone of
4 km (2.5 mi) prior to foundation pile
driving at all times using the required
equipment, pile driving operations must
not commence or must shutdown if they
are currently active. All PSOs must be
located at the best vantage point(s) on
any platform, as determined by the Lead
PSO, in order to obtain 360-degree
visual coverage of the entire clearance
and shutdown zones, and as much of
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the Level B harassment zone as possible.
PAM operators may be located on a
vessel or remotely on-shore, and must
assist PSOs in ensuring full coverage of
the clearance and shutdown zones. The
PAM operator must monitor to and past
the clearance zones for large whales.
All on-duty PSOs must remain in realtime contact with the on-duty PAM
operator(s). PAM operators must
immediately communicate all acoustic
detections of marine mammals to PSOs,
including any determination regarding
species identification, distance, and
bearing (where relevant) relative to the
pile being driven and the degree of
confidence (e.g., possible, probable
detection) in the determination. The
PAM operator must inform the Lead
PSO(s) on duty of animal detections
approaching or within applicable ranges
of interest to the activity occurring via
the data collection software system (i.e.,
Mysticetus or similar system) who must
be responsible for requesting that the
designated crewmember implement the
necessary mitigation procedures (i.e.,
delay). All on-duty PSOs and PAM
operator(s) must remain in contact with
the on-duty construction personnel
responsible for implementing
mitigations (e.g., delay to pile driving)
to ensure communication on marine
mammal observations can easily,
quickly, and consistently occur between
all on-duty PSOs, PAM operator(s), and
on-water Project personnel. It would be
the responsibility of the PSO(s) on duty
to communicate the presence of marine
mammals as well as to communicate the
action(s) that are necessary to ensure
mitigation and monitoring requirements
are implemented as appropriate.
At least three PSOs (on the pile
driving vessel) and one PAM operator
would be on-duty and actively
monitoring for marine mammals 60
minutes before, during, and 30 minutes
after foundation installation in
accordance with a NMFS-approved
PAM Plan. PAM would also be
conducted for at least 24 hours prior to
foundation pile driving activities, and
the PAM operator must review all
detections from the previous 24-hour
period prior to pile driving activities to
increase situational awareness.
Throughout the year (June through
December), at least three PSOs would
also be on-duty and actively monitoring
from PSO support vessels. There would
be at least two PSO support vessels with
on-duty PSOs during any pile driving
activities from June through December.
In addition to monitoring duties,
PSOs and PAM operators are
responsible for data collection. The data
collected by PSO and PAM operators
and subsequent analysis provide the
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necessary information to inform an
estimate of the amount of take that
occurred during the project, better
understand the impacts of the project on
marine mammals, address the
effectiveness of monitoring and
mitigation measures, and to adaptively
manage activities and mitigation in the
future. Data reported includes
information on marine mammal
sightings, activity occurring at time of
sighting, monitoring conditions, and if
mitigative actions were taken.
For all visual monitoring efforts and
marine mammal sightings, NMFS
proposes that the following information
must be collected and reported to NMFS
OPR: the date and time that monitored
activity begins or ends, the construction
activities occurring during each
observation period, the watch status
(i.e., sighting made by PSO on/off effort,
opportunistic, crew, alternate vessel/
platform), the PSO who sighted the
animal, the time of sighting; the weather
parameters (e.g., wind speed, percent
cloud cover, visibility), the water
conditions (e.g., Beaufort sea state, tide
state, water depth); all marine mammal
sightings, regardless of distance from
the construction activity; species (or
lowest possible taxonomic level
possible), the pace of the animal(s), the
estimated number of animals
(minimum/maximum/high/low/best),
the estimated number of animals by
cohort (e.g., adults, yearlings, juveniles,
calves, group composition, etc.), the
description (i.e., as many distinguishing
features as possible of each individual
seen, including length, shape, color,
pattern, scars or markings, shape and
size of dorsal fin, shape of head, and
blow characteristics), the description of
any marine mammal behavioral
observations (e.g., observed behaviors
such as feeding or traveling) and
observed changes in behavior, including
an assessment of behavioral responses
thought to have resulted from the
specific activity, the animal’s closest
distance and bearing from the pile being
driven and estimated time entered or
spent within the Level A harassment
and/or Level B harassment zone(s), use
of noise attenuation device(s), and
specific phase of activity (e.g., soft-start
for pile driving, active pile driving, etc.),
the marine mammal occurrence in Level
A harassment or Level B harassment
zones, the description of any mitigationrelated action implemented, or
mitigation-related actions called for but
not implemented, in response to the
sighting (e.g., delay, shutdown, etc.) and
time and location of the action, and
other human activity in the area.
On May 19, 2023, Vineyard Wind
submitted a Pile Driving Monitoring
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Plan for the 2023 IHA, including an
Alternative Monitoring Plan, which was
approved by NMFS. The Plan included
details regarding PSO and PAM
monitoring protocols and equipment
proposed for use. More specifically, the
PAM portion of the plan included a
description of all proposed PAM
equipment, addressed how the proposed
passive acoustic monitoring must follow
standardized measurement, processing
methods, reporting metrics, and
metadata standards for offshore wind as
described in ‘‘NOAA and BOEM
Minimum Recommendations for Use of
Passive Acoustic Listening Systems in
Offshore Wind Energy Development
Monitoring and Mitigation Programs’’
(Van Parijs et al., 2021). This plan also
identified the efficacy of the technology
at detecting marine mammals in the
clearance and shutdown zones under all
of the various conditions anticipated
during construction, including varying
weather conditions, sea states, and in
consideration of the use of artificial
lighting. Vineyard Wind would be
required to submit an updated
Foundation Installation Pile Driving
Marine Mammal Monitoring Plan to
NMFS Office of Protected Resources for
review, and the Plan must be approved
by NMFS prior to the start of foundation
pile driving.
ensure monitoring is conducted
appropriately and the reporting
frequency is such that Vineyard Wind
would be required to make adjustments
quickly (e.g., add additional sound
attenuation) to ensure marine mammals
are not experiencing noise levels above
those considered in this analysis. For
recommended SFV protocols for impact
pile driving, please consult ISO 18406
‘‘Underwater acoustics—Measurement
of radiated underwater sound from
percussive pile driving’’ (2017).
Vineyard Wind would be required to
submit an updated SFV plan to NMFS
Office of Protected Resources for review,
and the Plan must be approved by
NMFS prior to the start of foundation
pile driving.
For any pile driving activities, they
would also be required to submit
interim and final SFV data results to
NMFS and make corrections to the noise
attenuation systems in the case that any
SFV measurements demonstrate noise
levels are above those expected
assuming 6 dB of attenuation. These
frequent and immediate reports would
allow NMFS to better understand the
sound fields to which marine mammals
are being exposed and require
immediate corrective action should they
be misaligned with anticipated noise
levels within our analysis.
Sound Field Verification
Vineyard Wind would be required to
conduct thorough SFV measurements
during impact pile driving activity
associated with the installation of, at
minimum, the first monopile foundation
and abbreviated SFV measurements
during impact installation of the
remaining monopiles to demonstrate
noise levels are at or below those
measured during the 2023 Vineyard
Wind construction campaign (Ku¨sel et
al., 2024). NMFS recognizes that the
SFV data collected in 2023 occurred in
warmer weather months and that water
temperature can affect the sound speed
profile and, thus, propagation rates.
Therefore, if impact pile driving takes
place in December, thorough SFV
measurements must be conducted
during impact pile driving activity
associated with the installation of, at
minimum, the first monopile
foundation. Subsequent SFV
measurements would also be required
should larger piles be installed or if
additional piles are driven that are
anticipated to produce louder sound
fields than those previously measured
(e.g., higher hammer energy, greater
number of strikes, etc.). The
measurements and reporting associated
with SFV can be found in the IHA. The
proposed requirements are extensive to
Reporting
Prior to any construction activities
occurring, Vineyard Wind would
provide a report to NMFS OPR that
demonstrates that all Vineyard Wind
personnel, which includes the vessel
crews, vessel captains, PSOs, and PAM
operators have completed all required
training. NMFS would require
standardized and frequent reporting
from Vineyard Wind during the active
period of the IHA. All data collected
relating to the Project would be
recorded using industry-standard
software (e.g., Mysticetus or a similar
software) installed on field laptops and/
or tablets. Vineyard Wind would be
required to submit weekly, monthly,
annual, and situational reports.
Vineyard Wind must review SFV results
within 24 hours to determine whether
measurements exceeded modeled (Level
A harassment) and expected (Level B
harassment) thresholds.
Vineyard Wind must provide the
initial results of the SFV measurements
to NMFS OPR in an interim report after
each foundation installation event as
soon as they are available and prior to
a subsequent foundation installation,
but no later than 48 hours after each
completed foundation installation
event. The report must include, at
minimum: hammer energies/schedule
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used during pile driving, including the
total number of strikes and the
maximum hammer energy, peak sound
pressure level (SPLpk), root-mean-square
sound pressure level that contains 90
percent of the acoustic energy (SPLrms),
and sound exposure level (SEL, in
single strike for pile driving, SELss,), for
each hydrophone, including at least the
maximum, arithmetic mean, minimum,
median (L50) and L5 (95 percent
exceedance) statistics for each metric;
estimated marine mammal Level A
harassment and Level B harassment
isopleths, calculated using the
maximum-over-depth L5 (95 percent
exceedance level, maximum of both
hydrophones) of the associated sound
metric, comparison of 2023 measured
results against the measured marine
mammal Level A harassment and Level
B harassment acoustic isopleths,
estimated transmission loss coefficients,
pile identifier name, location of the pile
and each hydrophone array in latitude/
longitude, depths of each hydrophone,
one-third-octave band single strike SEL
spectra, if filtering is applied, full filter
characteristics, and hydrophone
specifications including the type,
model, and sensitivity. Vineyard Wind
would also be required to report any
immediate observations which are
suspected to have a significant impact
on the results including but not limited
to: observed noise mitigation system
issues, obstructions along the
measurement transect, and technical
issues with hydrophones or recording
devices. If any in-situ calibration checks
for hydrophones reveal a calibration
drift greater than 0.75 dB, pistonphone
calibration checks are inconclusive, or
calibration checks are otherwise not
effectively performed, Vineyard Wind
would be required to indicate full
details of the calibration procedure,
results, and any associated issues in the
48-hour interim reports.
Vineyard Wind must review
abbreviated SFV results for each pile
within 24 hours of completion of the
foundation installation (inclusive of pile
driving and any drilling), and, assuming
measured levels at 750 m did not exceed
the thresholds defined during thorough
SFV, does not need to take any
additional action. Results of abbreviated
SFV must be submitted with the weekly
pile driving report.
The final results of SFV
measurements from each foundation
installation must be submitted as soon
as possible, but no later than 90 days
following completion of each event’s
SFV measurements. The final reports
must include all details prescribed
above for the interim report as well as,
at minimum, the following: the peak
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sound pressure level (SPLpk), the rootmean-square sound pressure level that
contains 90 percent of the acoustic
energy (SPLrms), the single strike sound
exposure level (SELss), the integration
time for SPLrms, the spectrum, and the
24-hour cumulative SEL extrapolated
from measurements at all hydrophones.
The final report must also include at
least the maximum, mean, minimum,
median (L50) and L5 (95 percent
exceedance) statistics for each metric,
the SEL and SPL power spectral density
and/or one-third octave band levels
(usually calculated as decidecade band
levels) at the receiver locations should
be reported, the sound levels reported
must be in median, arithmetic mean,
and L5 (95 percent exceedance) (i.e.,
average in linear space), and in dB,
range of transmission loss coefficients,
the local environmental conditions,
such as wind speed, transmission loss
data collected on-site (or the sound
velocity profile), baseline pre- and postactivity ambient sound levels
(broadband and/or within frequencies of
concern), a description of depth and
sediment type, as documented in the
Construction and Operation Plan (COP),
at the recording and foundation
installation locations, the extents of the
measured Level A harassment and Level
B harassment zone(s), hammer energies
required for pile installation and the
number of strikes per pile, the
hydrophone equipment and methods
(i.e., recording device, bandwidth/
sampling rate; distance from the pile
where recordings were made; the depth
of recording device(s)), a description of
the SFV measurement hardware and
software, including software version
used, calibration data, bandwidth
capability and sensitivity of
hydrophone(s), any filters used in
hardware or software, any limitations
with the equipment, and other relevant
information; the spatial configuration of
the noise attenuation device(s) relative
to the pile, a description of the noise
abatement system and operational
parameters (e.g., bubble flow rate,
distance deployed from the pile, etc.),
and any action taken to adjust the noise
abatement system. A discussion which
includes any observations which are
suspected to have a significant impact
on the results including but not limited
to: observed noise mitigation system
issues, obstructions along the
measurement transect, and technical
issues with hydrophones or recording
devices.
If at any time during the project
Vineyard Wind becomes aware of any
issue(s) that may (to any reasonable
subject-matter expert, including the
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persons performing the measurements
and analysis) call into question the
validity of any measured Level A
harassment or Level B harassment
isopleths to a significant degree, which
were previously transmitted or
communicated to NMFS OPR, Vineyard
Wind must inform NMFS OPR within 1
business day of becoming aware of this
issue or before the next pile is driven,
whichever comes first.
Weekly Report—During foundation
installation activities, Vineyard Wind
would be required to compile and
submit weekly marine mammal
monitoring reports for foundation
installation pile driving to NMFS OPR
that document the daily start and stop
of all pile driving activities, the start
and stop of associated observation
periods by PSOs, details on the
deployment of PSOs, a record of all
detections of marine mammals (acoustic
and visual), any mitigation actions (or if
mitigation actions could not be taken,
provide reasons why), and details on the
noise abatement system(s) (e.g., system
type, distance deployed from the pile,
bubble rate, etc.). Weekly reports will be
due on Wednesday for the previous
week (Sunday to Saturday). The weekly
reports are also required to identify
which turbines become operational and
when (a map must be provided).
Monthly Report—Vineyard Wind
would be required to compile and
submit monthly reports to NMFS OPR
that include a summary of all
information in the weekly reports,
including project activities carried out
in the previous month, vessel transits
(number, type of vessel, and route),
number of piles installed, all detections
of marine mammals, and any mitigative
actions taken. Monthly reports would be
due on the 15th of the month for the
previous month. The monthly report
would also identify which turbines
become operational and when (a map
must be provided).
Final Annual Reporting—Vineyard
Wind would be required to submit its
draft annual report to NMFS OPR on all
visual and acoustic monitoring
conducted under the IHA within 90
calendar days of the completion of
activities occurring under the IHA. A
final annual report must be prepared
and submitted within 60 calendar days
following receipt of any NMFS
comments on the draft report.
Information contained within this report
is described at the beginning of this
section.
Situational Reporting—Specific
situations encountered during the
Project would require immediate
reporting. For instance, if a NARW is
sighted with no visible injuries or
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entanglement at any time by project
PSOs or project personnel, Vineyard
Wind must immediately report the
sighting to NMFS as soon as possible or
within 24 hours after the initial sighting.
All NARW acoustic detections within a
24-hour period should be collated into
one spreadsheet and reported to NMFS
as soon as possible but must be reported
within 24 hours. Vineyard Wind should
report sightings and acoustic detections
by downloading and completing the
Real-Time NARW Reporting Template
spreadsheet found here: https://
www.fisheries.noaa.gov/resource/
document/template-datasheet-real-timenorth-atlantic-right-whale-acoustic-andvisual. Vineyard Wind would save the
completed spreadsheet as a ‘‘.csv’’ file
and email it to NMFS Northeast
Fisheries Science Center Protected
Resources Division (NEFSC–PRD
(ne.rw.survey@noaa.gov), NMFS Greater
Atlantic Regional Fisheries Office
(GARFO)-PRD (nmfs.gar.incidentaltake@noaa.gov), and NMFS OPR
(pr.itp.monitoringreports@noaa.gov). If
the sighting is in the southeast (North
Carolina through Florida), sightings
should be reported via the template and
to the Southeast Hotline 877–WHALE–
HELP (877–942–5343) with the
observation information provided below
(PAM detections are not reported to the
Hotline). If Vineyard Wind is unable to
report a sighting through the
spreadsheet within 24 hours, Vineyard
Wind should call the relevant regional
hotline (Greater Atlantic Region [Maine
through Virginia] Hotline 866–755–
6622; Southeast Hotline 877–WHALE–
HELP) with the observation information
provided below. Observation
information would include: the time
(note time format), date (MM/DD/
YYYY), location (latitude/longitude in
decimal degrees; coordinate system
used) of the observation, number of
whales, animal description/certainty of
observation (follow up with photos/
video if taken), reporter’s contact
information, and lease area number/
project name, PSO/personnel name who
made the observation, and PSO provider
company (if applicable). If Vineyard
Wind is unable to report via the
template or the regional hotline,
Vineyard Wind would enter the sighting
via the WhaleAlert app (https://
www.whalealert.org/). If this is not
possible, the sighting should be reported
to the U.S. Coast Guard via channel 16.
The report to the Coast Guard must
include the same information as would
be reported to the hotline (see above).
PAM detections would not be reported
to WhaleAlert or the U.S. Coast Guard.
If a non-NARW large whale is observed,
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Vineyard Wind would be required to
report the sighting via WhaleAlert app
(https://www.whalealert.org/) as soon as
possible but within 24 hours.
In the event that personnel involved
in the Project discover a stranded,
entangled, injured, or dead marine
mammal, Vineyard Wind must
immediately report the observation to
NMFS. If in the Greater Atlantic Region
(Maine through Virginia), call the NMFS
Greater Atlantic Stranding Hotline (866–
755–6622), and if in the Southeast
Region (North Carolina through Florida)
call the NMFS Southeast Stranding
Hotline (877–WHALE–HELP, 877–942–
5343). Separately, Vineyard Wind must
report the incident within 24 hours to
NMFS OPR (PR.ITP.MonitoringReports@
noaa.gov) and, if in the Greater Atlantic
Region to the NMFS GARFO
(nmfs.gar.incidental-take@noaa.gov) or
if in the Southeast Region, to the NMFS
Southeast Regional Office (SERO;
secmammalreports@noaa.gov). Note,
the stranding hotline may request the
report be sent to the local stranding
network response team. The report must
include contact information (e.g., name,
phone number, etc.), time, date, and
location (i.e., specify coordinate system)
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), photographs or
video footage of the animal(s) (if
available), and general circumstances
under which the animal was discovered.
If the injury, entanglement, or death
was caused by a project activity,
Vineyard Wind would be required to
immediately cease all activities until
NMFS OPR is able to review the
circumstances of the incident and
determine what, if any, additional
measures are appropriate to ensure
compliance with the terms of the IHA.
NMFS OPR may impose additional
measures to minimize the likelihood of
further prohibited take and ensure
MMPA compliance consistent with the
adaptive management provisions.
Vineyard Wind could not resume their
activities until notified by NMFS OPR.
In the event of a suspected or
confirmed vessel strike of a marine
mammal by any vessel associated with
the Project or other means by which
Project activities caused a non-auditory
injury or death of a marine mammal,
Vineyard Wind must immediately
report the incident to NMFS. If in the
Greater Atlantic Region (Maine through
Virginia), call the NMFS Greater
Atlantic Stranding Hotline (866–755–
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6622), and if in the Southeast Region
(North Carolina through Florida) call the
NMFS Southeast Stranding Hotline
(877–WHALE–HELP, 877–942–5343).
Separately, Vineyard Wind must
immediately report the incident to
NMFS OPR (PR.ITP.MonitoringReports@
noaa.gov) and, if in the Greater Atlantic
Region to the NMFS GARFO
(nmfs.gar.incidental-take@noaa.gov) or
if in the Southeast Region, to the NMFS
SERO (secmammalreports@noaa.gov).
The report must include time, date, and
location (i.e., specify coordinate
system)) of the incident, species
identification (if known) or description
of the animal(s) involved (i.e.,
identifiable features including animal
color, presence of dorsal fin, body shape
and size, etc.), vessel strike reporter
information (name, affiliation, email for
person completing the report), vessel
strike witness (if different than reporter)
information (e.g., name, affiliation,
phone number, platform for person
witnessing the event, etc.), vessel name
and/or MMSI number; vessel size and
motor configuration (inboard, outboard,
jet propulsion), vessel’s speed leading
up to and during the incident, vessel’s
course/heading and what operations
were being conducted (if applicable),
part of vessel that struck marine
mammal (if known), vessel damage
notes, status of all sound sources in use
at the time of the strike, if the marine
mammal was seen before the strike
event, description of behavior of the
marine mammal before the strike event
(if seen) and behavior immediately
following the strike, 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, etc.) immediately
preceding the strike, estimated (or
actual, if known) size and length of
marine mammal that was struck, if
available, description of the presence
and behavior of any other marine
mammals immediately preceding the
strike, other animal-specific details if
known (e.g., length, sex, age class),
behavior or estimated fate of the marine
mammal post-strike (e.g., dead, injured
but alive, injured and moving, external
visible wounds (linear wounds,
propeller wounds, non-cutting bluntforce trauma wounds), blood or tissue
observed in the water, status unknown,
disappeared), to the extent practicable,
any photographs or video footage of the
marine mammal(s), and, any additional
notes the witness may have from the
interaction. For any numerical values
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provided (i.e., location, animal length,
vessel length, etc.), please provide if
values are actual or estimated.
Vineyard Wind would be required to
immediately cease activities until the
NMFS OPR is able to review the
circumstances of the incident and
determine what, if any, additional
measures are appropriate to ensure
compliance with the terms of the IHA.
NMFS OPR may impose additional
measures to minimize the likelihood of
further prohibited take and ensure
MMPA compliance. Vineyard Wind
may not resume their activities until
notified by NMFS OPR.
Sound Field Verification—Vineyard
Wind would be required to submit
interim SFV reports after each
foundation installation within 48 hours.
A final SFV report for all monopile
foundation installation monitoring
would be required within 90 days
following completion of acoustic
monitoring.
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., populationlevel effects). An estimate of the number
of takes alone is not enough information
on which to base an impact
determination. In addition to
considering estimates of the number of
marine mammals that might be ‘‘taken’’
through harassment, NMFS considers
other factors, such as the likely nature
of any impacts or responses (e.g.,
intensity, duration), the context of any
impacts or responses (e.g., critical
reproductive time or location, foraging
impacts affecting energetics), 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’ implementing
regulations (54 FR 40338, September 29,
1989), the impacts from other past and
ongoing anthropogenic activities are
incorporated into this analysis via their
impacts on the baseline (e.g., as
reflected in the regulatory status of the
species, population size and growth rate
where known, ongoing sources of
human-caused mortality, or ambient
noise levels).
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In the Estimated Take section, we
estimated the maximum number of
takes by Level A harassment and Level
B harassment that could occur from
Vineyard Wind’s specified activities
based on the methods described. The
impact that any given take would have
is dependent on many case-specific
factors that need to be considered in the
negligible impact analysis (e.g., the
context of behavioral exposures such as
duration or intensity of a disturbance,
the health of impacted animals, the
status of a species that incurs fitnesslevel impacts to individuals, etc.). In
this notice of proposed IHA, we
evaluate the likely impacts of the
harassment takes that are proposed to be
authorized in the context of the specific
circumstances surrounding these
predicted takes. We also collectively
evaluate this information, as well as
other more taxa-specific information
and mitigation measure effectiveness, in
group-specific discussions that support
our negligible impact conclusions for
each stock. As described above, no
serious injury or mortality is expected
or proposed to be authorized for any
species or stock.
We base our analysis and preliminary
negligible impact determination on the
number of takes that are proposed to be
authorized, and extensive qualitative
consideration of other contextual factors
that influence the degree of impact of
the takes on the affected individuals and
the number and context of the
individuals affected.
To avoid repetition, we provide some
general analysis in this Negligible
Impact Analysis and Determination
section that applies to all the species
listed in table 3 given that some of the
anticipated effects of Vineyard Wind’s
construction activities on marine
mammals are expected to be relatively
similar in nature. Where there are
meaningful differences between species
or stocks—as is the case of the NARW—
they are included as separate
subsections below.
Last, we provide a negligible impact
determination for each species or stock,
providing species or stock-specific
information or analysis where
appropriate, for example for NARWs
given the population status. Organizing
our analysis by grouping species or
stocks that share common traits or that
would respond similarly to effects of
Vineyard Wind’s activities, and then
providing species- or stock-specific
information allows us to avoid
duplication while ensuring that we have
analyzed the effects of the specified
activities on each affected species or
stock.
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As described previously, no serious
injury or mortality is anticipated or
proposed to be authorized in this IHA.
Any Level A harassment proposed to be
authorized would be in the form of
auditory injury (i.e., PTS). For all
species, the amount of take proposed to
be authorized represents the maximum
amount of Level A harassment and
Level B harassment that is reasonably
expected to occur.
Behavioral Disturbance
In general, NMFS anticipates that
impacts on an individual that has been
harassed are likely to be more intense
when exposed to higher received levels
and for a longer duration (though this is
in no way a strictly linear relationship
for behavioral effects across species,
individuals, or circumstances) and less
severe impacts result when exposed to
lower received levels and for a brief
duration. However, there is also growing
evidence of the importance of
contextual factors such as distance from
a source in predicting marine mammal
behavioral response to sound—i.e.,
sounds of a similar level emanating
from a more distant source have been
shown to be less likely to evoke a
response of equal magnitude (DeRuiter
and Doukara, 2012; Falcone et al.,
2017). As described in the Potential
Effects of Specified Activities on Marine
Mammals and their Habitat section, the
intensity and duration of any impact
resulting from exposure to Vineyard
Wind’s activities is dependent upon a
number of contextual factors including,
but not limited to, sound source
frequencies, whether the sound source
is moving towards the animal, hearing
ranges of marine mammals, behavioral
state at time of exposure, status of
individual exposed (e.g., reproductive
status, age class, health) and an
individual’s experience with similar
sound sources. Southall et al. (2021),
Ellison et al. (2012) and Moore and
Barlow (2013), among others, emphasize
the importance of context (e.g.,
behavioral state of the animals, distance
from the sound source) in evaluating
behavioral responses of marine
mammals to acoustic sources. Level B
Harassment of marine mammals may
consist of behavioral modifications (e.g.,
avoidance, temporary cessation of
foraging or communicating, changes in
respiration or group dynamics, masking)
and may include auditory impacts in
the form of temporary hearing loss. In
addition, some of the lower-level
physiological stress responses (e.g.,
change in respiration, change in heart
rate) discussed previously would likely
co-occur with the behavioral
modifications, although these
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physiological responses are more
difficult to detect, and fewer data exist
relating these responses to specific
received levels of sound. Take by Level
B harassment, then, may have a stressrelated physiological component as
well; however, we would not expect
Vineyard Wind’s pile driving activities
to produce conditions of long-term and
continuous exposure to noise leading to
long-term physiological stress responses
in marine mammals that could affect
reproduction or survival.
In the range of behavioral effects that
might be expected to be part of a
response that qualifies as an instance of
Level B harassment (which by nature of
the way it is modeled/counted, occurs
within 1 day), the less severe end might
include exposure to comparatively
lower levels of a sound, at a greater
distance from the animal, for a few or
several minutes. A less severe exposure
of this nature could result in a
behavioral response such as avoiding an
area that an animal would otherwise
have chosen to move through or feed in
for some amount of time or breaking off
one or a few feeding bouts. More severe
effects could occur if an animal gets
close enough to the source to receive a
comparatively higher level, is exposed
continuously to one source for a longer
time or is exposed intermittently to
different sources throughout a day. Such
effects might result in an animal having
a more severe flight response and
leaving a larger area for a day or more
or potentially losing feeding
opportunities for a day. However, such
severe behavioral effects are expected to
occur infrequently.
Many species perform vital functions,
such as feeding, resting, traveling, and
socializing on a diel cycle (24-hour
cycle). Behavioral reactions to noise
exposure, when taking place in a
biologically important context, such as
disruption of critical life functions,
displacement, or avoidance of important
habitat, are more likely to be significant
if they last more than 1 day or recur on
subsequent days (Southall et al., 2007)
due to diel and lunar patterns in diving
and foraging behaviors observed in
many cetaceans (Baird et al., 2008;
Barlow et al., 2020; Henderson et al.,
2016; Schorr et al., 2014). It is important
to note the water depth in the LIA is
shallow (ranging up to 37 to 49.5 m), so
deep diving species such as sperm
whales are not expected to be engaging
in deep foraging dives when exposed to
noise above NMFS harassment
thresholds during the specified
activities. Therefore, we do not
anticipate impacts to deep foraging
behavior to be impacted by the specified
activities.
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It is also important to identify that the
estimated number of takes does not
necessarily equate to the number of
individual animals Vineyard Wind
expects to harass (which is lower), but
rather to the instances of take (i.e.,
exposures above the Level B harassment
thresholds) that may occur. Some
individuals of a species may experience
recurring instances of take over multiple
days throughout the year while some
members of a species or stock may
experience one exposure as they move
through an area, which means that the
number of individuals taken is smaller
than the total estimated takes. In short,
for species that are more likely to be
migrating through the area and/or for
which only a comparatively smaller
number of takes are predicted (e.g.,
some of the mysticetes), it is more likely
that each take represents a different
individual whereas for non-migrating
species with larger amounts of predicted
take, we expect that the total anticipated
takes represent exposures of a smaller
number of individuals of which some
would be taken across multiple days.
Impact pile driving for foundation
installation is anticipated to have the
greatest impacts. For these reasons,
impacts are proposed to be minimized
through implementation of mitigation
measures, including use of a sound
attenuation system, soft-starts, the
implementation of clearance zones that
would facilitate a delay to pile driving
commencement, and implementation of
shutdown zones. All these measures are
designed to avoid or minimize
harassment. For example, given
sufficient notice through the use of softstart, marine mammals are expected to
move away from a sound source that is
disturbing prior to becoming exposed to
very loud noise levels. The requirement
to couple visual monitoring and PAM
before and during all foundation
installation will increase the overall
capability to detect marine mammals
compared to one method alone.
Occasional, milder behavioral
reactions are unlikely to cause long-term
consequences for individual animals or
populations, and even if some smaller
subset of the takes is in the form of a
longer (several hours or a day) and more
severe response, if they are not expected
to be repeated over numerous or
sequential days, impacts to individual
fitness are not anticipated. Also, the
effect of disturbance is strongly
influenced by whether it overlaps with
biologically important habitats when
individuals are present—avoiding
biologically important habitats will
provide opportunities to compensate for
reduced or lost foraging (Keen et al.,
2021). Nearly all studies and experts
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agree that infrequent exposures of a
single day or less are unlikely to impact
an individual’s overall energy budget
(Farmer et al., 2018; Harris et al., 2017;
King et al., 2015; National Academy of
Science, 2017; New et al., 2014;
Southall et al., 2007; Villegas-Amtmann
et al., 2015).
Temporary Threshold Shift
TTS is one form of Level B
harassment that marine mammals may
incur through exposure to US Wind’s
activities and, as described earlier, the
proposed takes by Level B harassment
may represent takes in the form of direct
behavioral disturbance, TTS, or both. As
discussed in the Potential Effects of
Specified Activities on Marine
Mammals and their Habitat section, in
general, TTS can last from a few
minutes to days, be of varying degree,
and occur across different frequency
bandwidths, all of which determine the
severity of the impacts on the affected
individual, which can range from minor
to more severe. Impact pile driving is a
broadband noise sources but generates
sounds in the lower frequency ranges
(with most of the energy below 1–2 kHz,
but with a small amount energy ranging
up to 20 kHz); therefore, in general and
all else being equal, we would
anticipate the potential for TTS is
higher in low-frequency cetaceans (i.e.,
mysticetes) than other marine mammal
hearing groups and would be more
likely to occur in frequency bands in
which they communicate. However, we
would not expect the TTS to span the
entire communication or hearing range
of any species given that the frequencies
produced by these activities do not span
entire hearing ranges for any particular
species. Additionally, though the
frequency range of TTS that marine
mammals might sustain would overlap
with some of the frequency ranges of
their vocalizations, the frequency range
of TTS from Vineyard Wind’s pile
driving activities would not typically
span the entire frequency range of one
vocalization type, much less span all
types of vocalizations or other critical
auditory cues for any given species. In
addition, the proposed mitigation
measures further reduce the potential
for TTS in mysticetes.
Generally, both the degree of TTS and
the duration of TTS would be greater if
the marine mammal is exposed to a
higher level of energy (which would
occur when the peak dB level is higher
or the duration is longer). The threshold
for the onset of TTS was discussed
previously (see Estimated Take). An
animal would have to approach closer
to the source or remain in the vicinity
of the sound source appreciably longer
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to increase the received SEL, which
would be unlikely considering the
proposed mitigation and the nominal
speed of the receiving animal relative to
the stationary sources such as impact
pile driving. The recovery time of TTS
is also of importance when considering
the potential impacts from TTS. In TTS
laboratory studies (as discussed in
Potential Effects of Specified Activities
on Marine Mammals and Their Habitat),
some using exposures of almost an hour
in duration or up to 217 SEL, almost all
individuals recovered within 1 day (or
less, often in minutes), and we note that
while the pile driving activities last for
hours a day, it is unlikely that most
marine mammals would stay in the
close vicinity of the source long enough
to incur more severe TTS. Overall, given
the few instances in which any
individual might incur TTS, the low
degree of TTS and the short anticipated
duration, and the unlikely scenario that
any TTS would overlap the entirety of
an individual’s critical hearing range, it
is unlikely that TTS (of the nature
expected to result from the project’s
activities) would result in behavioral
changes or other impacts that would
impact any individual’s (of any hearing
sensitivity) reproduction or survival.
Permanent Threshold Shift
NMFS proposes to authorize a very
small amount of take by PTS to some
marine mammal individuals. The
numbers of proposed takes by Level A
harassment are relatively low for all
marine mammal stocks and species
(table 11). We anticipate that PTS may
occur from exposure to impact pile
driving, which produces sounds that are
both impulsive and primarily
concentrated in the lower frequency
ranges (below 1 kHz) (David, 2006;
Krumpel et al., 2021).
There are no PTS data on cetaceans
and only one instance of PTS being
induced in older harbor seals
(Reichmuth et al., 2019). However,
available TTS data (of mid-frequency
hearing specialists exposed to mid- or
high-frequency sounds (Southall et al.,
2007, 2019; NMFS, 2018)) suggest that
most threshold shifts occur in the
frequency range of the source up to one
octave higher than the source. We
would anticipate a similar result for
PTS. Further, no more than a small
degree of PTS is expected to be
associated with any of the incurred
Level A harassment, given it is unlikely
that animals would stay in the close
vicinity of a source for a duration long
enough to produce more than a small
degree of PTS.
PTS would consist of minor
degradation of hearing capabilities
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occurring predominantly at frequencies
one-half to one octave above the
frequency of the energy produced by
pile driving (i.e., the low-frequency
region below 2 kHz) (Cody and
Johnstone, 1981; McFadden, 1986;
Finneran, 2015), not severe hearing
impairment. If hearing impairment
occurs from impact pile driving, it is
most likely that the affected animal
would lose a few decibels in its hearing
sensitivity, which in most cases is not
likely to meaningfully affect its ability
to forage and communicate with
conspecifics. In addition, during impact
pile driving, given sufficient notice
through use of soft-start prior to
implementation of full hammer energy
during impact pile driving, marine
mammals are expected to move away
from a sound source that is disturbing
prior to it resulting in severe PTS.
Auditory Masking or Communication
Impairment
The potential impacts of masking on
an individual are similar to those
discussed for TTS (e.g., decreased
ability to communicate, forage
effectively, or detect predators), but an
important difference is that masking
only occurs during the period of the
signal, versus TTS, which continues
beyond the duration of the signal. Also,
though masking can result from the sum
of exposure to multiple signals, none of
these signals might individually cause
TTS. Fundamentally, masking is
referred to as a chronic effect because
one of the key potential harmful
components of masking is the fact that
an animal would have reduced ability to
hear or interpret critical cues. This
becomes much more likely to cause a
problem the longer it is occurring.
Inherent in the concept of masking is
the fact that the potential for the effect
is only present during the times that the
animal and the source are in close
enough proximity for the effect to occur
(and further, this time period would
need to coincide with a time that the
animal was utilizing sounds at the
masked frequency).
As our analysis has indicated, we
expect that impact pile driving may
occur for several, albeit intermittent,
hours per day, for multiple days.
Masking is fundamentally more of a
concern at lower frequencies (which are
pile driving dominant frequencies),
because low-frequency signals
propagate significantly further than
higher frequencies and because they are
more likely to overlap both the narrower
low-frequency calls of mysticetes, as
well as many non-communication cues
related to fish and invertebrate prey,
and geologic sounds that inform
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navigation. As mentioned above (see
Description of Marine Mammals in the
Area of Specified Activities), the LIA
does not overlap critical habitat or BIAs
for any species, and temporary
avoidance of the pile driving area by
marine mammals would likely displace
animals to areas of sufficient habitat. In
summary, the nature of Vineyard
Wind’s activities, paired with habitat
use patterns by marine mammals, does
not support the likelihood of take due
to masking effects or that masking
would have the potential to affect
reproductive success or survival, and
are we not proposing to authorize such
take.
Impact on Habitat and Prey
Construction activities may result in
fish and invertebrate mortality or injury
very close to the source, and Vineyard
Wind’s activities may cause some fish to
leave the area of disturbance. It is
anticipated that any mortality or injury
would be limited to a very small subset
of available prey and the
implementation of mitigation measures
such as the use of a noise attenuation
system during impact pile driving
would further limit the degree of
impact. Behavioral changes in prey in
response to construction activities could
temporarily impact marine mammals’
foraging opportunities in a limited
portion of the foraging range but,
because of the relatively small area of
the habitat that may be affected at any
given time (e.g., around a pile being
driven) and the temporary nature of the
disturbance on prey species, the impacts
to marine mammal habitat are not
expected to cause significant or longterm negative consequences. There is no
indication that displacement of prey
would impact individual fitness and
health, particularly since unconsumed
prey would likely still be available in
the environment in most cases following
the cessation of acoustic exposure.
Cable presence is not anticipated to
impact marine mammal habitat, as these
would be buried, and any
electromagnetic fields emanating from
the cables are not anticipated to result
in consequences that would impact
marine mammals’ prey to the extent
they would be unavailable for
consumption. Although many species of
marine mammal prey can detect
electromagnetic fields, previous studies
have shown little impacts on habitat use
(Hutchinson et al., 2018). Burying the
cables and the inclusion of protective
shielding on cables will also minimize
any impacts of electromagnetic fields on
marine mammal prey.
The presence of wind turbines within
the Lease Area could have longer-term
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impacts on marine mammal habitat, as
the project would result in the
persistence of the structures within
marine mammal habitat for more than
30 years. For piscivorous marine
mammal species, the presence of
structures could result in a beneficial
reef effect which may lead to increases
in the availability of prey. However,
turbine presence and operation is,
generally likely to result in certain
oceanographic effects in the marine
environment, and may adversely alter
aggregations and distribution of marine
mammal zooplankton prey through
changing the strength of tidal currents
and associated fronts, changes in
stratification, primary production, the
degree of mixing, and stratification in
the water column (Chen et al., 2021;
Johnson et al., 2021; Christiansen et al.,
2022; Dorrell et al., 2022). In the
recently released BOEM and NOAA
Fisheries North Atlantic Right Whale
Strategy (BOEM et al., 2024), the
agencies identify the conceptual
pathway by which changes to ocean
circulation could potentially lead to
fitness reduction of North Atlantic right
whales, who primarily forage on
copepods (see figure 2). As described in
the Potential Effects to Marine Mammal
Habitat section, there is uncertainty
regarding the intensity (or magnitude)
and spatial extent of turbine operation
impacts on marine mammals habitat,
including planktonic prey. Recently, a
National Academy of Sciences,
Engineering, and Medicine panel of
independent experts concluded that the
impacts of offshore wind operations on
North Atlantic right whales and their
habitat in the Nantucket Shoals region
is uncertain due to the limited data
available at this time and recognized
what data is available is largely based
on models from the North Sea that have
not been validated by observations
(NAS, 2023). The report also identifies
that major oceanographic changes have
occurred to the Nantucket Shoals region
over the past 25 years and it will be
difficult to isolate from the much larger
variability introduced by natural and
other anthropogenic sources (including
climate change).
As discussed in the Description of the
Specified Activity section, this IHA
addresses the take incidental to the
installation of 15 foundations, which
will gradually become operational
following construction completion.
While there are likely to be
oceanographic impacts from the
presence of operating turbines,
meaningful oceanographic impacts
relative to stratification and mixing that
would significantly affect marine
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mammal foraging and prey over large
areas in key foraging habitats, resulting
in the reproduction or survival of any
individual marine mammals, are not
anticipated from the Vineyard Wind
activities covered under this proposed
IHA, yet are likely to be comparatively
minor, if impacts do occur.
Mitigation To Reduce Impacts on All
Species
The proposed IHA includes a variety
of mitigation measures designed to
minimize impacts on all marine
mammals, with a focus on NARWs (the
latter is described in more detail below).
For impact pile driving of foundation
piles, 10 overarching mitigation
measures are proposed, which are
intended to reduce both the number and
intensity of marine mammal takes: (1)
seasonal/time of day work restrictions;
(2) use of multiple PSOs to visually
observe for marine mammals (with any
detection within specifically designated
zones triggering a delay or shutdown);
(3) use of PAM to acoustically detect
marine mammals, with a focus on
detecting baleen whales (with any
detection within designated zones
triggering delay or shutdown); (4)
implementation of clearance zones; (5)
implementation of shutdown zones; (6)
use of soft-start; (7) use of noise
attenuation technology; (8) maintaining
situational awareness of marine
mammal presence through the
requirement that any marine mammal
sighting(s) by Vineyard Wind’s
personnel must be reported to PSOs; (9)
sound field verification monitoring; and
(10) Vessel Strike Avoidance measures
to reduce the risk of a collision with a
marine mammal and vessel.
The Proposed Mitigation section
discusses the manner in which the
required mitigation measures reduce the
magnitude and/or severity of the take of
marine mammals, including the
following. For activities with large
harassment isopleths, Vineyard Wind
would be required to reduce the noise
levels generated to the lowest levels
practicable. Use of a soft-start during
impact pile driving will allow animals
to move away from (i.e., avoid) the
sound source prior to applying higher
hammer energy levels needed to install
the pile (Vineyard Wind would not use
a hammer energy greater than necessary
to install piles). Clearance zone and
shutdown zone implementation, which
are required when marine mammals are
within given distances associated with
certain impact thresholds for all
activities, would reduce the magnitude
and severity of marine mammal take.
Additionally, the use of multiple PSOs,
PAM, and maintaining awareness of
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marine mammal sightings reported in
the region would aid in detecting
marine mammals that would trigger the
implementation of the mitigation
measures.
Mysticetes
Five mysticete species (comprising
five stocks) of cetaceans (NARW,
humpback whale, fin whale, sei whale,
and minke whale) may be taken by
harassment. These species, to varying
extents, utilize the specific geographic
region, including the LIA, for the
purposes of migration, foraging, and
socializing. Mysticetes are in the lowfrequency hearing group.
Behavioral data on mysticete
reactions to pile driving noise are scant.
Kraus et al. (2019) predicted that the
three main impacts of offshore wind
farms on marine mammals would
consist of displacement, behavioral
disruptions, and stress. Broadly, we can
look to studies that have focused on
other noise sources such as seismic
surveys and military training exercises,
which suggest that exposure to loud
signals can result in avoidance of the
sound source (or displacement if the
activity continues for a longer duration
in a place where individuals would
otherwise have been staying, which is
less likely for mysticetes in this area),
disruption of foraging activities (if they
are occurring in the area), local masking
around the source, associated stress
responses, and impacts to prey, as well
as TTS or PTS in some cases.
Mysticetes encountered in the LIA are
expected to be migrating through and/or
engaged in foraging behavior. The extent
to which an animal engages in these
behaviors in the area is species-specific
and varies seasonally. Many mysticetes
are expected to predominantly be
migrating through the LIA towards or
from primary feeding habitats (e.g., Cape
Cod Bay, Great South Channel, and Gulf
of St. Lawrence). While we have
acknowledged above that mortality,
hearing impairment, or displacement of
mysticete prey species may result
locally from impact pile driving, given
the very short duration of and broad
availability of prey species in the area
and the availability of alternative
suitable foraging habitat for the
mysticete species most likely to be
affected, any impacts on mysticete
foraging are expected to be minor.
Whales temporarily displaced from the
LIA are 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 habitats,
including to the east near Nantucket
Shoals. In addition, any displacement of
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whales or interruption of foraging bouts
would be expected to be relatively
temporary in nature.
The potential for repeated exposures
of individuals is dependent upon their
residency time, with migratory animals
unlikely to be exposed on repeated
occasions and animals remaining in the
area more likely to be exposed more
than once. For mysticetes, where
relatively low numbers of speciesspecific take by Level B harassment are
predicted (compared to the abundance
of each mysticete species or stock; see
table 11) and movement patterns suggest
that individuals would not necessarily
linger in a particular area for multiple
days, each predicted take likely
represents an exposure of a different
individual; with perhaps a subset of
takes for a few species potentially
representing a few repeated of a limited
number of individuals across multiple
days. In other words, the behavioral
disturbance to any individual mysticete
would, therefore, be expected to most
likely occur within a single day, or
potentially across a few days, and
therefore would not be expected to
impact the animal’s fitness for
reproduction or survival.
In general, the duration of exposures
would not be continuous throughout
any given day and pile driving would
not occur on all consecutive days due to
weather delays or any number of
logistical constraints Vineyard Wind has
identified. Species-specific analysis
regarding potential for repeated
exposures and impacts is provided
below.
Humpback whales, minke whales, fin
whales and sei whales are the mysticete
species for which PTS is anticipated
and proposed to be authorized. As
described previously, PTS for
mysticetes from some project activities
may overlap frequencies used for
communication, navigation, or detecting
prey. However, given the nature and
duration of the activity, the mitigation
measures, and likely avoidance
behavior, any PTS is expected to be of
a small degree, would be limited to
frequencies where pile driving noise is
concentrated (i.e., only a small subset of
their expected hearing range) and would
not be expected to impact individuals’
fitness for reproductive success or
survival.
NARWs
NARWs are listed as endangered
under the ESA and as both depleted and
strategic under the MMPA. As described
in the Potential Effects to Marine
Mammals and Their Habitat section,
NARWs are threatened by a low
population abundance, higher than
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average mortality rates, and lower than
average reproductive rates. Recent
studies have reported individuals
showing high stress levels (e.g.,
Corkeron et al., 2017) and poor health,
which has further implications on
reproductive success and calf survival
(Christiansen et al., 2020; Stewart et al.,
2021, 2022). As described below, a UME
has been designated for NARWs. Given
this, the status of the NARW population
is of heightened concern and, therefore,
merits additional analysis and
consideration.
This proposed IHA would authorize
seven takes of NARW by Level B
harassment only, which equates to
approximately 2.1 percent of the stock’s
abundance, if each take were considered
to be of a different individual. No Level
A harassment, serious injury, or
mortality is anticipated or proposed to
be authorized for this species.
As described in the Description of
Marine Mammals in the Area of
Specified Activities section, NARWs are
presently experiencing an ongoing UME
(beginning in June 2017). Preliminary
findings support human interactions,
specifically vessel strikes and
entanglements, as the cause of death for
the majority of NARWs. Given the
current status of the NARW, the loss of
even one individual could significantly
impact the population. Level B
harassment of NARWs resulting from
the Project’s activities is expected to
primarily be in the form of temporary
avoidance of the immediate area of
construction. Required mitigation
measures will ensure the least
practicable adverse impact and the
proposed number of takes of NARWs
would not exacerbate or compound the
effects of the ongoing UME.
In general, NARWs in the LIA are
expected to be engaging in migratory,
feeding, and/or social behavior.
Migrating NARWs would typically be
moving through the LIA, rather than
lingering for extended periods of time
(thereby limiting the potential for repeat
exposures); however, foraging whales
may remain in the LIA, with an average
residence time of 13 days between
December and May (Quintana-Rizzo et
al., 2021). SNE, including the LIA, is
part of a known migratory corridor for
NARWs and may be a stopover site for
migrating NARWs moving to or from
southeastern calving grounds and
northern foraging grounds. NARWs are
primarily concentrated in the
northeastern and southeastern sections
of the Massachusetts Wind Energy Area
(MA WEA) (i.e., east of the LIA) during
the summer (June-August) and winter
(December-February) while distribution
likely shifts to the west, closer to the
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LIA, into the Rhode Island/
Massachusetts Wind Energy Area (RI/
MA WEA) in the spring (March-May)
(Quintana-Rizzo et al., 2021). However,
NARWs range outside of the LIA for
their main feeding, breeding, and
calving activities. It is important to note
that there would be a restriction on
impact pile driving activities from
January through May, with pile driving
only allowed in December with
approval from NMFS and BOEM.
Foundation installation is of concern,
given loud sound levels. However, as
described above, foundation installation
would only occur during times when,
based on the best available scientific
data, NARWs are less frequently
encountered and less likely to be
engaged in critical foraging behavior
(although NMFS recognizes NARWs
may forage year-round in SNE). The
potential types, severity, and magnitude
of impacts are also anticipated to mirror
that described in the general Mysticetes
section above, including avoidance (the
most likely outcome), changes in
foraging or vocalization behavior,
masking, a small amount of TTS, and
temporary physiological impacts (e.g.,
change in respiration, change in heart
rate). Importantly, the effects of the
activities are expected to be sufficiently
low-level and localized to specific areas
as to not meaningfully impact important
behaviors such as migration and
foraging for NARWs. As noted above, for
NARWs, this IHA would authorize up to
seven takes, by Level B harassment.
These takes are expected to be in the
form of temporary behavioral
disturbance, such as slight displacement
(but not abandonment) of migratory
habitat or temporary cessation of
feeding. Further, given many of these
exposures are generally expected to
occur to different individual right
whales migrating through (i.e., many
individuals would not be impacted on
more than 1 day in a year), with some
subset potentially being exposed on no
more than a few days within the year,
they are unlikely to result in energetic
consequences that could affect
reproduction or survival of any
individuals.
Overall, NMFS expects that any
behavioral harassment of NARWs
incidental to the specified activities
would not result in changes to their
migration patterns or foraging success,
as only temporary avoidance of an area
during construction is expected to
occur. As described previously, NARWs
migrate, forage, or socialize in the LIA
but are not expected to remain in this
habitat for extensive durations relative
to core foraging habitats to the east,
south of Nantucket and Martha’s
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Vineyard, Cape Cod Bay, or the Great
South Channel (Quintana-Rizzo et al.,
2021). Any temporarily displaced
animals would be able to return to or
continue to travel through the LIA and
subsequently utilize this habitat once
activities have ceased.
Although acoustic masking may occur
in the vicinity of the foundation
installation activities, based on the
acoustic characteristics of noise
associated with pile driving (e.g.,
frequency spectra, short duration of
exposure, NMFS expects masking
effects to be minimal during impact pile
driving). In addition, masking would
likely only occur during the period of
time that a NARW is in the relatively
close vicinity of pile driving, which is
expected to be intermittent within a day
and confined to the months in which
NARWs are at lower densities and
primarily moving through the area.
TTS,could also occur in some of the
exposed animals, making it more
difficult for those individuals to hear or
interpret acoustic cues within the
frequency range (and slightly above) of
sound produced during impact pile
driving; however, any TTS would likely
be of low amount, limited duration, and
limited to frequencies where most
construction noise is centered (below 2
kHz). NMFS expects that right whale
hearing sensitivity would return to preexposure levels shortly after migrating
through the area or moving away from
the sound source.
As described in the Potential Effects
to Marine Mammals and Their Habitat
section of this notice, the distance of the
receiver from the source influences the
severity of response, with greater
distances typically eliciting less severe
responses. NMFS recognizes NARWs
migrating could be pregnant females (in
the fall) and cows with older calves (in
spring) and that these animals may
slightly alter their migration course in
response to any foundation pile driving;
however, we anticipate that course
diversion would be of small magnitude.
Hence, while some avoidance of the
pile-driving activities may occur, we
anticipate any avoidance behavior of
migratory NARWs would be similar to
that of gray whales (Tyack et al., 1983),
on the order of hundreds of meters up
to 1 to 2 km. This diversion from a
migratory path otherwise uninterrupted
by the project’s activities is not expected
to result in meaningful energetic costs
that would impact annual rates of
recruitment of survival. NMFS expects
that NARWs would be able to avoid
areas during periods of active noise
production while not being forced out of
this portion of their habitat.
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NARW presence in the LIA is yearround. However, abundance during
summer months is lower compared to
the winter months with spring and fall
serving as ‘‘shoulder seasons’’ wherein
abundance waxes (fall) or wanes
(spring). Even in consideration of recent
habitat use and distribution shifts,
Vineyard Wind would still be installing
monopile foundations when the
presence of NARWs is expected to be
lower.
Given this year-round habitat usage,
in recognition that where and when
whales may actually occur during
project activities is unknown as it
depends on the annual migratory
behaviors, NMFS is requiring a suite of
mitigation measures designed to reduce
impacts to NARWs to the maximum
extent practicable. These mitigation
measures (e.g., seasonal/daily work
restrictions, vessel separation distances,
and reduced vessel speed) would not
only avoid the likelihood of vessel
strikes but also would minimize the
severity of behavioral disruptions (e.g.,
through sound reduction using
attenuation systems and reduced
temporal overlap of project activities
and NARWs). This would help further
ensure that takes by Level B harassment
that are estimated to occur would not
affect reproductive success or
survivorship of individuals through
detrimental impacts to energy intake or
cow/calf interactions during migratory
transit.
As described in the Description of
Marine Mammals in the Area of
Specified Activities section, the
Vineyard Wind Offshore Wind Project is
being constructed within the NARW
migratory corridor BIA, which
represents areas and months within
which a substantial portion of a species
or population is known to migrate. The
area over which NARWs may be
harassed is relatively small compared to
the width of the migratory corridor. The
width of the migratory corridor in this
area is approximately 210.1 km (while
the width of the Lease Area, at the
longest point at which it crosses the
BIA, is approximately 14.5 km). NARWs
may be displaced from their normal
path and preferred habitat in the
immediate activity area (primarily from
pile driving activities), however, we do
not anticipate displacement to be of
high magnitude (e.g., beyond a few
kilometers); therefore, any associated
bio-energetic expenditure is anticipated
to be small. Although NARWs may
forage in the LIA, there are no known
breeding or calving areas within the
LIA. Prey species are mobile (e.g.,
calanoid copepods can initiate rapid
and directed escape responses) and are
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broadly distributed throughout the LIA.
Therefore, any impacts to prey that may
occur are also unlikely to impact marine
mammals.
The most significant measure to
minimize impacts to individual NARWs
is the seasonal moratorium on all
foundation installation activities from
January 1 through May 31 and the
limitation on these activities in
December (e.g., only work with approval
from NMFS) when NARW abundance in
the LIA is expected to be highest. NMFS
also expects this measure to greatly
reduce the potential for mother-calf
pairs to be exposed to impact pile
driving noise above the Level B
harassment threshold during their
annual spring migration through SNE
from calving grounds to primary
foraging grounds (e.g., Cape Cod Bay).
NMFS expects that the severity of any
take of NARWs would be reduced due
to the mitigation measures that would
ensure that any exposures above the
Level B harassment threshold would
result in only short-term effects to
individuals exposed.
Foundation installation may only
begin in the absence of NARWs (based
on visual and passive acoustic
monitoring). Once foundation
installation activities have commenced,
NMFS anticipates NARWs would avoid
the area, utilizing nearby waters to carry
on pre-exposure behaviors. However,
foundation installation activities must
be shut down if a NARW is sighted at
any distance or acoustically detected at
any distance within the PAM
monitoring zone, unless a shutdown is
not feasible due to risk of injury or loss
of life. Shutdown would be required
anywhere if NARWs are detected within
or beyond the Level B harassment zone,
further minimizing the duration and
intensity of exposure. These measures
are designed to avoid PTS and also
reduce the severity of Level B
harassment, including the potential for
TTS. While some TTS could occur,
given the mitigation measures (e.g.,
delay pile driving upon a sighting or
acoustic detection and shutting down
upon a sighting or acoustic detection),
the potential for TTS to occur is low.
NMFS anticipates that if NARWs go
undetected and they are exposed to
foundation installation noise, it is
unlikely a NARW would approach the
sound source locations to the degree
that they would expose themselves to
very high noise levels. This is because
typical observed whale behavior
demonstrates likely avoidance of
harassing levels of sound where
possible (Richardson et al., 1985).
The clearance and shutdown
measures are most effective when
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detection efficiency is maximized, as
the measures are triggered by a sighting
or acoustic detection. To maximize
detection efficiency, NMFS would
require the combination of PAM and
visual observers. NMFS also would
require communication protocols with
other project vessels and other
heightened awareness efforts (e.g., daily
monitoring of NARW sighting
databases) such that as a NARW
approaches the source (and thereby
could be exposed to higher noise energy
levels), PSO detection efficacy would
increase, the whale would be detected,
and a delay to commencing foundation
installation or shutdown (if feasible)
would occur. In addition, the
implementation of a soft-start for impact
pile driving would provide an
opportunity for whales to move away
from the source if they are undetected,
reducing received levels.
As described above, no serious injury
or mortality, or Level A harassment of
NARWs is anticipated or proposed to be
authorized. Extensive NARW-specific
mitigation measures (beyond the robust
suite required for all species) are
expected to further minimize the
amount and severity of Level B
harassment.
Given the documented habitat use
within the LIA, the seven instances of
take by Level B harassment could
include seven whales disturbed on one
day each within the year, or it could
represent a smaller number of whales
impacted on 2 or 3 days, should NARWs
briefly use the LIA as a ‘‘stopover’’ site
and stay or swim in and out of the LIA
for more than day. At any rate, any
impacts to NARWs are expected to be in
the form of lower level behavioral
disturbance, given the extensive
mitigation measures.
Given the magnitude and severity of
the impacts discussed above, and in
consideration of the required mitigation
and other information presented,
Vineyard Wind’s activities are not
expected to result in impacts on the
reproduction or survival of any
individuals, much less affect annual
rates of recruitment or survival. For
these reasons, we have determined that
the take (by Level B harassment)
anticipated and proposed to be
authorized would have a negligible
impact on the NARW.
Fin Whale
The fin whale is listed as endangered
under the ESA, and the western North
Atlantic stock is considered both
depleted and strategic under the MMPA.
No UME has been designated for this
species or stock. No serious injury or
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mortality is anticipated or proposed to
be authorized for this species.
This IHA would authorize up to seven
takes, by harassment only, over the 1
year period. The maximum allowable
take by Level A harassment and Level
B harassment, is one and six,
respectively (which equates to
approximately 0.10 percent of the stock
abundance, if each take were considered
to be of a different individual). Given
the close proximity of a fin whale
feeding BIA (2,933 km2) from March
through October, and that SNE is
generally considered a feeding area, it is
likely that the seven takes could
represent a few whales taken 2–3 times
annually.
Level B harassment is expected to be
in the form of behavioral disturbance,
primarily avoidance of the LIA where
foundation installation is occurring and
some low-level TTS and masking that
may limit the detection of acoustic cues
for relatively brief periods of time. We
anticipate any potential PTS would be
minor (limited to a few dB), and any
PTS or TTS would be concentrated at
half or one octave above the frequency
band of pile driving noise (most sound
is below 2 kHz) which does not include
the full predicted hearing range of fin
whales. If TTS is incurred, hearing
sensitivity would likely return to preexposure levels relatively shortly after
exposure ends. Any masking or
physiological responses would also be
of low magnitude and severity for
reasons described above.
Fin whales are present in the waters
off of New England year-round and are
one of the most frequently observed
large whales and cetaceans in
continental shelf waters, principally
from Cape Hatteras, North Carolina in
the Mid-Atlantic northward to Nova
Scotia, Canada (Sergeant, 1977; Sutcliffe
and Brodie, 1977; CETAP, 1982; Hain et
al., 1992; Geo-Marine, 2010; BOEM
2012; Edwards et al., 2015; Hayes et al.,
2023). In SNE, fin whales densities are
highest in the spring and summer
months (Kraus et al., 2016; Roberts et
al., 2023) though detections do occur in
spring and fall (Watkins et al., 1987;
Clark and Gagnon, 2002; Geo-Marine,
2010; Morano et al., 2012; Van Parijs et
al., 2023). However, fin whales feed
more extensively in waters in the Great
South Channel north to the Gulf Maine
into the Gulf of St. Lawrence, areas
north and east of the LIA (Hayes et al.,
2023).
As described previously, the LIA is in
close proximity (approximately 8.0 km;
5.0 mi) to a small fin whale feeding BIA
(2,933 km2) east of Montauk Point, New
York (figure 2.3 in LaBrecque et al.,
2015) that is active from March to
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October. Foundation installations have
seasonal work restrictions (i.e., spatial
and temporal) such that the temporal
overlap between the specified activities
and the active BIA timeframe would
exclude the months of March, April,
and May. A separate larger year-round
feeding BIA (18,015 km2) located to the
east in the southern Gulf of Maine does
not overlap with the LIA and is located
substantially further away
(approximately 76.4 km (47.5 mi)), and
would thus not be impacted by project
activities. We anticipate that if foraging
is occurring in the LIA and foraging
whales are exposed to noise levels of
sufficient strength, they would avoid the
LIA and move into the remaining area
of the feeding BIA that would be
unaffected to continue foraging without
substantial energy expenditure or,
depending on the time of year, travel to
the larger year-round feeding BIA.
Given the documented habitat use
within the area, some of the individuals
taken would likely be exposed on
multiple days. However, low level
impacts are generally expected from any
fin whale exposure. Given the
magnitude and severity of the impacts
discussed above (including no more
than seven takes over the course of the
IHA, and a maximum allowable take by
Level A harassment and Level B
harassment of one and six, respectively)
and in consideration of the required
mitigation and other information
presented, Vineyard Wind’s activities
are not expected to result in impacts on
the reproduction or survival of any
individuals, much less affect annual
rates of recruitment or survival. For
these reasons, we have determined that
the take by harassment anticipated and
proposed to be authorized will have a
negligible impact on the western North
Atlantic stock of fin whales.
Humpback Whale
The West Indies DPS of humpback
whales is not listed as threatened or
endangered under the ESA but the Gulf
of Maine stock, which includes
individuals from the West Indies DPS,
is considered strategic under the
MMPA. However, as described in the
Description of Marine Mammals in the
Area of Specified Activities section,
humpback whales along the Atlantic
Coast have been experiencing an active
UME as elevated humpback whale
mortalities have occurred along the
Atlantic coast from Maine through
Florida since January 2016. Of the cases
examined, approximately 40 percent
had evidence of human interaction
(vessel strike or entanglement). Despite
the UME, the relevant population of
humpback whales (the West Indies
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31059
breeding population, or DPS of which
the Gulf of Maine stock is a part)
remains stable at approximately 12,000
individuals and takes of humpback
whales proposed for authorization
would not exacerbate or compound the
effects of the ongoing UME.
This IHA would authorize up to six
takes by harassment only, over the 1
year period. The maximum allowable
take by Level A harassment and Level
B harassment is two and four,
respectively (this equates to
approximately 0.43 percent of the stock
abundance, if each take were considered
to be of a different individual). Given
that feeding is considered the principal
activity of humpback whales in SNE
waters, these takes could represent a
few whales exposed two or three times
during the year.
In the western North Atlantic,
humpback whales feed during spring,
summer, and fall over a geographic
range encompassing the eastern coast of
the U.S. Feeding is generally considered
to be focused in areas north of the LIA,
including in a feeding BIA in the Gulf
of Maine/Stellwagen Bank/Great South
Channel, but has been documented off
the coast of SNE and as far south as
Virginia (Swingle et al., 1993). Foraging
animals tend to remain in the area for
extended durations to capitalize on the
food sources.
Assuming humpback whales who are
feeding in waters within or surrounding
the LIA behave similarly, we expect that
the predicted instances of disturbance
could consist of some individuals that
may be exposed on multiple days if they
are utilizing the area as foraging habitat.
As with other baleen whales, if
migrating, such individuals would
likely be exposed to noise levels from
the project above the harassment
thresholds only once during migration
through the LIA.
For all the reasons described in the
Mysticetes section above, we anticipate
any potential PTS and TTS would be
concentrated at half or one octave above
the frequency band of pile driving noise
(most sound is below 2 kHz) which does
not include the full predicted hearing
range of baleen whales. If TTS is
incurred, hearing sensitivity would
likely return to pre-exposure levels
relatively shortly after exposure ends.
Any masking or physiological responses
would also be of low magnitude and
severity for reasons described above.
Given the magnitude and severity of
the impacts discussed above (including
no more than six takes over the course
of the 1-year IHA, and a maximum
allowable take by Level A harassment
and Level B harassment of two and four,
respectively), and in consideration of
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the proposed mitigation measures and
other information presented, Vineyard
Wind’s activities are not expected to
result in impacts on the reproduction or
survival of any individuals, much less
affect annual rates of recruitment or
survival. For these reasons, we have
determined that the take by harassment
anticipated and proposed to be
authorized will have a negligible impact
on the Gulf of Maine stock of humpback
whales.
Minke Whale
Minke whales are not listed under the
ESA, and the Canadian East Coast stock
is neither considered depleted nor
strategic under the MMPA. There are no
known areas of specific biological
importance in or adjacent to the LIA. As
described in the Description of Marine
Mammals in the Area of Specified
Activities section, a UME has been
designated for this species but is
pending closure. No serious injury or
mortality is anticipated or proposed to
be authorized for this species.
This IHA would authorize up to 1
take by Level A harassment and 28 takes
by Level B harassment over the 1-year
period (equating to approximately 0.13
percent of the stock abundance, if each
take were considered to be of a different
individual). As described in the
Description of Marine Mammals in the
Area of Specified Activities section,
minke whales inhabit coastal waters
during much of the year and are
common offshore the U.S. eastern
seaboard with a strong seasonal
component in the continental shelf and
in deeper, off-shelf waters (CETAP,
1982; Hayes et al., 2022; Hayes et al.,
2023). Spring through fall are times of
relatively widespread and common
acoustic occurrence on the continental
shelf. From September through April,
minke whales are frequently detected in
deep-ocean waters throughout most of
the western North Atlantic (Clark and
Gagnon, 2002; Risch et al., 2014; Hayes
et al., 2023). Because minke whales are
migratory and their known feeding areas
are north and east of the LIA, including
a feeding BIA in the southwestern Gulf
of Maine and George’s Bank, they would
be more likely to be transiting through
(with each take representing a separate
individual), though it is possible that
some subset of the individual whales
exposed could be taken up to a few
times during the effective period of the
IHA.
As previously detailed in the
Description of Marine Mammals in the
Area of Specified Activities section,
there is a UME for minke whales along
the Atlantic coast, from Maine through
South Carolina, with the highest
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number of deaths in Massachusetts,
Maine, and New York. Preliminary
findings in several of the whales have
shown evidence of human interactions
or infectious diseases. However, we note
that the population abundance is greater
than 21,000, and the take by harassment
proposed to be authorized through this
action is not expected to exacerbate the
UME.
We anticipate the impacts of this
harassment to follow those described in
the general Mysticetes section above.
Any potential PTS would be minor
(limited to a few dB) and any PTS or
TTS would be of short duration and
concentrated at half or one octave above
the frequency band of pile driving noise
(most sound is below 2 kHz) which does
not include the full predicted hearing
range of minke whales. If TTS is
incurred, hearing sensitivity would
likely return to pre-exposure levels
relatively shortly after exposure ends.
Level B harassment would be
temporary, with primary impacts being
temporary displacement from the LIA
but not abandonment of any migratory
or foraging behavior.
Given the magnitude and severity of
the impacts discussed above (including
no more than 29 takes of the course of
the 1-year IHA, and a maximum
allowable take by Level A harassment
and Level B harassment of 1 and 28,
respectively), and in consideration of
the proposed mitigation and other
information presented, Vineyard Wind’s
activities are not expected to result in
impacts on the reproduction or survival
of any individuals, much less affect
annual rates of recruitment or survival.
For these reasons, we have determined
that the take by harassment anticipated
and proposed to be authorized will have
a negligible impact on the Canadian
Eastern Coastal stock of minke whales.
Sei Whale
Sei whales are listed as endangered
under the ESA, and the Nova Scotia
stock is considered both depleted and
strategic under the MMPA. There are no
known areas of specific biological
importance in or adjacent to the LIA,
and no UME has been designated for
this species or stock. No serious injury
or mortality is anticipated or proposed
to be authorized for this species.
The IHA would authorize up to three
takes by harassment over the 1-year
period. The maximum allowable take by
Level A harassment and Level B
harassment is one and two, respectively
(combined, this annual take (n=3)
equates to approximately 0.05 percent of
the stock abundance, if each take were
considered to be of a different
individual). As described in the
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Description of Marine Mammals in the
Area of Specified Activities section,
most of the sei whale distribution is
concentrated in Canadian waters and
seasonally in northerly United States
waters, although they can occur yearround in SNE. Because sei whales are
migratory and their known feeding areas
are east and north of the LIA (e.g., there
is a feeding BIA in the Gulf of Maine),
they would be more likely to be moving
through (i.e., not foraging) and
considering this and the very low
number of total takes, it is unlikely that
any individual would be exposed more
than once within the effective period of
the IHA.
With respect to the severity of those
individual takes by Level B harassment,
we anticipate impacts to be limited to
low-level, temporary behavioral
responses with avoidance and potential
masking impacts in the vicinity of the
WTG installation to be the most likely
type of response. Any potential PTS and
TTS would likely be concentrated at
half or one octave above the frequency
band of pile driving noise (most sound
is below 2 kHz), which does not include
the full predicted hearing range of sei
whales. Moreover, any TTS would be of
a small degree. Any avoidance of the
LIA due to the Project’s activities would
be expected to be temporary.
Given the magnitude and severity of
the impacts discussed above (including
no more than three takes of the course
of the 1-year IHA, and a maximum
allowable take by Level A harassment
and Level B harassment, of one and two,
respectively), and in consideration of
the required mitigation and other
information presented, Vineyard Wind’s
activities are not expected to result in
impacts on the reproduction or survival
of any individuals, much less affect
annual rates of recruitment or survival.
For these reasons, we have determined
that the take by harassment anticipated
and proposed to be authorized will have
a negligible impact on the Nova Scotia
stock of sei whales.
Odontocetes
In this section, we include
information here that applies to all of
the odontocete species and stocks
addressed below. Odontocetes include
dolphins, porpoises, and all other
whales possessing teeth and we further
divide them into the following
subsections: sperm whales, dolphins
and small whales, and harbor porpoises.
These sub-sections include more
specific information, as well as
conclusions for each stock represented.
No serious injury or mortality is
anticipated or proposed to be
authorized. We anticipate that, given
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ranges of individuals (i.e., that some
individuals remain within a small area
for some period of time) and nonmigratory nature of some odontocetes in
general (especially as compared to
mysticetes), a larger subset of these
takes are more likely to represent
multiple exposures of some number of
individuals than is the case for
mysticetes, though some takes may also
represent one-time exposures of an
individual. While we expect animals to
avoid the area during foundation
installation, their habitat range is
extensive compared to the area
ensonified during these activities. As
such, NMFS expects any avoidance
behavior to be limited to the area near
the sound source.
As described earlier, Level B
harassment may include direct
disruptions in behavioral patterns (e.g.,
avoidance, changes in feeding or
vocalizations), as well as those
associated with stress responses or TTS.
While masking could also occur during
foundation installation, it would only
occur in the vicinity of and during the
duration of the activity, and would not
generally occur in a frequency range
that overlaps most odontocete
communication or any echolocation
signals. The proposed mitigation
measures (e.g., use of sound attenuation
systems, implementation of clearance
and shutdown zones) would also
minimize received levels such that the
expected severity of any behavioral
response would be less than exposure to
unmitigated noise exposure.
Any masking or TTS effects are
anticipated to be of low severity. First,
while the frequency range of pile
driving falls within a portion of the
frequency range of most odontocete
vocalizations, odontocete vocalizations
span a much wider range than the low
frequency construction activities
planned for the project. Also, as
described above, recent studies suggest
odontocetes have a mechanism to selfmitigate the impacts of noise exposure
(i.e., reduce hearing sensitivity), which
could potentially reduce TTS impacts.
Any masking or TTS is anticipated to be
limited and would typically only
interfere with communication within a
portion of an odontocete’s range and as
discussed earlier, the effects would only
be expected to be of a short duration
and for TTS, a relatively small degree.
Furthermore, odontocete echolocation
occurs predominantly at frequencies
significantly higher than low frequency
construction activities. Therefore, there
is little likelihood that threshold shift
would interfere with feeding behaviors.
The waters off the coast of
Massachusetts are used by several
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odontocete species. However, none
except the sperm whale are listed under
the ESA and there are no known
habitats of particular importance. In
general, odontocete habitat ranges are
far-reaching along the Atlantic coast of
the U.S. and the waters off of New
England, including the LIA, do not
contain any particularly unique
odontocete habitat features.
Sperm Whale
Sperm whales are listed as
endangered under the ESA, and the
North Atlantic stock is considered both
depleted and strategic under the MMPA.
The North Atlantic stock spans the east
coast out into oceanic waters well
beyond the U.S. EEZ. Although listed as
endangered, the primary threat faced by
the sperm whale across its range (i.e.,
commercial whaling) has been
eliminated. Current potential threats to
the species globally include vessel
strikes, entanglement in fishing gear,
anthropogenic noise, exposure to
contaminants, climate change, and
marine debris. There is no currently
reported trend for the stock and
although the species is listed as
endangered under the ESA, there are no
current related issues or events
associated with the status of the stock
that cause particular concern (e.g., no
UMEs). There are no known areas of
biological importance (e.g., critical
habitat or BIAs) in or near the LIA. No
mortality or serious injury is anticipated
or proposed to be authorized for this
species.
The IHA would authorize up to two
takes by Level B harassment over the 1year period, which equates to
approximately 0.05 percent of the stock
abundance. If sperm whales are present
in the LIA during any Project activities,
they will likely be only transient
visitors, although foraging and social
behavior may occur in the shallow
waters off SNE (Westell et al., 2024).
However, the potential for TTS is low
for reasons described in the general
Odontocete section. If it does occur, any
hearing shift would be small and of a
short duration. Because foraging is
expected to be rare in the LIA, TTS is
not expected to interfere with foraging
behavior.
Given the magnitude and severity of
the impacts discussed above (including
no more than two takes by Level B
harassment over the course of the 1-year
IHA, and in consideration of the
required mitigation and other
information presented, Vineyard Wind’s
activities are not expected to result in
impacts on the reproduction or survival
of any individuals, much less affect
annual rates of recruitment or survival.
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For these reasons, we have determined
that the take by Level B harassment
anticipated and proposed to be
authorized will have a negligible impact
on the North Atlantic stock of sperm
whales.
Dolphins and Small Whales (Including
Delphinids)
The five species and stocks included
in this group (which are indicated in
table 3 in the Delphinidae family) are
not listed under the ESA, and nor are
they listed as depleted or strategic under
the MMPA. There are no known areas
of specific biological importance in or
around the LIA. As described above for
any of these species and no UMEs have
been designated for any of these species.
No serious injury or mortality is
anticipated or proposed to be authorized
for these species.
The five delphinid species
(constituting five stocks) with takes
proposed to be authorized for the
Project are Atlantic white-sided
dolphin, bottlenose dolphin, longfinned pilot whale, Risso’s dolphin, and
common dolphin. The IHA would allow
for the total authorization of 3 to 462
takes (depending on species) by Level B
harassment, over the 1-year period.
Overall, this annual take equates to
approximately 0.01 (Risso’s dolphin) to
up to 0.27 (common dolphin) percent of
the stock abundance (if each take were
considered to be of a different
individual, which is not likely the case),
depending on the species.
The number of takes, likely movement
patterns of the affected species, and the
intensity of any Level B harassment,
combined with the availability of
alternate nearby foraging habitat
suggests that the likely impacts would
not impact the reproduction or survival
of any individuals. While delphinids
may be taken on several occasions, none
of these species are known to have small
home ranges within the LIA or known
to be particularly sensitive to
anthropogenic noise. Some TTS can
occur, but it would be limited to the
frequency ranges of the activity and any
loss of hearing sensitivity is anticipated
to return to pre-exposure conditions
shortly after the animals move away
from the source or the source ceases.
Across these species, the maximum
number of incidental takes, by Level B
harassment (no Level A harassment is
anticipated or proposed to be
authorized), proposed to be authorized
ranges between 3 (Risso’s dolphin) to
462 (common dolphin). Though the
estimated numbers of take are
comparatively higher than the numbers
for mysticetes, we note that for all
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species they are relatively low relative
to the population abundance.
As described above for odontocetes
broadly, given the number of estimated
takes for some species and the
behavioral patterns of odontocetes, we
anticipate that some of these instances
of take in a day represent multiple
exposures of a smaller number of
individuals, meaning the actual number
of individuals taken is lower. Although
some amount of repeated exposure to
some individuals across a few days
within the year is likely, the intensity of
any Level B harassment combined with
the availability of alternate nearby
foraging habitat suggests that the likely
impacts would not impact the
reproduction or survival of any
individuals.
Overall, the populations of all
delphinid and small whale species and
stocks for which we proposed to
authorize take are stable (no declining
population trends). None of these stocks
are experiencing existing UMEs. No
mortality, serious injury, or Level A
harassment is anticipated or proposed to
be authorized for any of these species.
Given the magnitude and severity of the
impacts discussed above and in
consideration of the required mitigation
and other information presented, as well
as the status of these stocks, the
specified activities are not expected to
result in impacts on the reproduction or
survival of any individuals, much less
affect annual rates of recruitment or
survival. For these reasons, we have
determined that the take by harassment
anticipated and proposed to be
authorized will have a negligible impact
on all of the following species and
stocks: Atlantic white-sided dolphins,
bottlenose dolphins, long-finned pilot
whales, Risso’s dolphins, and common
dolphins.
Harbor Porpoise
Harbor porpoises are not listed as
threatened or endangered under the
ESA, and the Gulf of Maine/Bay of
Fundy stock is neither considered
depleted or strategic under the MMPA.
The stock is found predominantly in
northern United States coastal waters
(less than 150 m depth) and up into
Canada’s Bay of Fundy (between New
Brunswick and Nova Scotia). Although
the population trend is not known, there
are no UMEs or other factors that cause
particular concern for this stock. No
mortality or non-auditory injury are
anticipated or proposed to be authorized
for this stock.
The IHA would authorize up to 113
takes, by harassment only. The
maximum allowable take by Level A
harassment and Level B harassment
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would be 3 and 110, respectively
(combined, this annual take (n=113)
which equates to approximately 0.19
percent of the stock abundance, if each
take were considered to be of a different
individual). Given the number of takes,
while many of the takes likely represent
exposures of different individuals on 1
day a year, some subset of the
individuals exposed could be taken up
to a few times annually.
Regarding the severity of takes by
Level A harassment and Level B
harassment, because harbor porpoises
are particularly sensitive to noise, it is
likely that a fair number of the
responses could be of a moderate
nature, particularly to foundation
installation. In response to foundation
installation, harbor porpoises are likely
to avoid the area during construction, as
previously demonstrated in Tougaard et
al. (2009) in Denmark, in Dahne et al.
(2013) in Germany, and in Vallejo et al.
(2017) in the United Kingdom, although
a study by Graham et al. (2019) may
indicate that the avoidance distance
could decrease over time. However,
foundation installation is scheduled to
occur off the coast of Massachusetts and
given alternative foraging areas, any
avoidance of the area by individuals is
not likely to impact the reproduction or
survival of any individuals.
With respect to PTS and TTS, the
effects on an individual are likely
relatively low, given the frequency
bands of pile driving (most energy
below 2 kHz) compared to harbor
porpoise hearing (150 Hz to 160 kHz,
peaking around 40 kHz). Specifically,
TTS is unlikely to impact hearing ability
in their more sensitive hearing ranges or
the frequencies in which they
communicate and echolocate. We
expect any PTS that may occur to be
within the very low end of their hearing
range where harbor porpoises are not
particularly sensitive and any PTS
would be of small magnitude. As such,
any PTS would not interfere with key
foraging or reproductive strategies
necessary for reproduction or survival.
As discussed in Hayes et al. (2022),
harbor porpoises are seasonally
distributed. During fall (October through
November) and spring (April through
June), harbor porpoises are widely
dispersed from New Jersey to Maine
with lower densities farther north and
south. 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. In
non-summer months they have been
seen from the coastline to deep waters
(>1800 m; Westgate et al., 1998),
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although the majority are found over the
continental shelf. While harbor
porpoises are likely to avoid the area
during any of the project’s construction
activities, as demonstrated during
European wind farm construction, the
time of year in which most work would
occur is when harbor porpoises are not
in highest abundance, and any work
that does occur would not result in the
species’ abandonment of the waters off
of Massachusetts.
Given the magnitude and severity of
the impacts discussed above, and in
consideration of the required mitigation
and other information presented, the
specified activities are not expected to
result in impacts on the reproduction or
survival of any individuals, much less
affect annual rates of recruitment or
survival. For these reasons, we have
determined that the take by harassment
anticipated and proposed to be
authorized will have a negligible impact
on the Gulf of Maine/Bay of Fundy
stock of harbor porpoises.
Phocids (Harbor Seals and Gray Seals)
The harbor seal and gray seal are not
listed under the ESA, and neither the
western North Atlantic stock of gray seal
nor the western North Atlantic stock of
harbor seal are considered depleted or
strategic under the MMPA. There are no
known areas of specific biological
importance in or around the LIA. As
described in the Description of Marine
Mammals in the Area of Specified
Activities section, a UME has been
designated for harbor seals and gray
seals and is described further below. No
serious injury or mortality is anticipated
or proposed to be authorized for this
species.
For the 2 seal species, the IHA would
authorize up to between 30 (harbor
seals) and 241 (gray seals) takes, by
harassment only. The maximum
allowable take for harbor seals by Level
A harassment and Level B harassment
would be 1 and 29, respectively
(combined, this take (n=30) equates to
approximately 0.05 percent of the stock
abundance, if each take were considered
to be of a different individual). No takes
by Level A harassment are anticipated
or proposed to be authorized for gray
seals. The maximum allowable take for
gray seals by Level B harassment (241)
equates to approximately 0.88 percent of
the stock abundance, if each take were
considered to be of a different
individual). Though gray seals and
harbor seals are considered migratory
and no specific feeding areas have been
defined for the area, while some of the
takes likely represent exposures of
different individuals on 1 day a year, it
is likely that some subset of the
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individuals exposed could be taken a
few times annually.
Harbor and gray seals occur in SNE
waters most often from December
through April. Seals are more likely to
be close to shore, such that exposure to
foundation installation would be
expected to be at low levels. Known
haulouts for seals occur along the shores
of Massachusetts.
As described in the Potential Effects
to Marine Mammals and Their Habitat
section, construction of wind farms in
Europe resulted in pinnipeds
temporarily avoiding construction areas
but returning within short time frames
after construction was complete (Carroll
et al., 2010; Hamre et al., 2011; Hastie
et al., 2015; Russell et al., 2016;
Brasseur et al., 2012). Effects on
pinnipeds that are taken by Level B
harassment in the LIA would likely be
limited to avoidance of the area
reactions such as increased swimming
speeds, increased surfacing time, or
decreased foraging (if such activity were
occurring). Most likely, individuals
would simply move away from the
sound source and be temporarily
displaced from those areas (Lucke et al.,
2006; Edren et al., 2010; Skeate et al.,
2012; Russell et al., 2016). Given the
low anticipated magnitude of impacts
from any given exposure (e.g.,
temporary avoidance), even repeated
Level B harassment across a few days of
some small subset of individuals, which
could occur, is unlikely to result in
impacts on the reproduction or survival
of any individuals. Moreover, pinnipeds
would benefit from the mitigation
measures described in the Proposed
Mitigation section.
As described above, noise from pile
driving is mainly low frequency, and
while any PTS and TTS that does occur
would fall within the lower end of
pinniped hearing ranges (50 Hz to 86
kHz), PTS and TTS would not occur at
frequencies around 5 kHz where
pinniped hearing is most susceptible to
noise-induced hearing loss (Kastelein et
al., 2018). In summary, any PTS and
TTS would be of small degree and not
occur across the entire, or even most
sensitive, hearing range. Hence, any
impacts from PTS and TTS are likely to
be of low severity and not interfere with
behaviors critical to reproduction or
survival.
Elevated numbers of harbor seal and
gray seal mortalities were first observed
in July 2018 and occurred across Maine,
New Hampshire, and Massachusetts
until 2020. Based on tests conducted so
far, the main pathogen found in the
seals belonging to that UME was
phocine distemper virus, although
additional testing to identify other
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factors that may be involved in this
UME are underway. In 2022, a pinniped
UME occurred in Maine with some
harbor and gray seals testing positive for
highly pathogenic avian influenza
(HPAI) H5N1. Neither UME (alone or in
combination) provides cause for
concern regarding population-level
impacts to any of these stocks. For
harbor seals, the population abundance
is over 61,000 and annual mortality/
serious injury (M/SI) (n=339) is well
below PBR (1,729) (Hayes et al., 2023).
The population abundance for gray seals
in the United States is over 27,000, with
an estimated overall abundance,
including seals in Canada, of
approximately 366,400 (Hayes et al.,
2023). In addition, the abundance of
gray seals is likely increasing in the U.S.
Atlantic, as well as in Canada (Hayes et
al., 2023).
Given the magnitude and severity of
the impacts of the Vineyard Wind
Project discussed above, and in
consideration of the required mitigation
and other information presented,
Vineyard Wind’s activities are not
expected to result in impacts on the
reproduction or survival of any
individuals, much less affect annual
rates of recruitment or survival. For
these reasons, we have determined that
the take by harassment anticipated and
proposed to be authorized will have a
negligible impact on harbor and gray
seals.
Negligible Impact Determination
No mortality or serious injury is
anticipated to occur or proposed to be
authorized. As described in the analysis
above, the impacts resulting from the
project’s activities cannot be reasonably
expected to, and are not reasonably
likely to, adversely affect any of the
species or stocks through effects on
annual rates of recruitment or survival.
Based on the analysis contained herein
of the likely effects of the specified
activity on marine mammals and their
habitat, and, taking into consideration
the implementation of the proposed
mitigation and monitoring measures,
NMFS preliminarily finds that the
marine mammal take from the proposed
activities would have a negligible
impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only incidental
take of small numbers of marine
mammals 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
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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. When the
predicted number of individuals to be
taken is fewer than one-third of the
species or stock abundance, the take is
considered to be of small numbers.
Additionally, other qualitative factors
may be considered in the analysis, such
as the temporal or spatial scale of the
activities.
NMFS is authorizing incidental take
by Level A harassment and/or Level B
harassment of 14 species of marine
mammals (with 14 managed stocks).
The estimated number of instances of
takes by combined Level A harassment
and Level B harassment relative to the
best available population abundance is
less than one-third for all affected
species and stocks. For 13 stocks, 1
percent or less of the stock abundance
is proposed for take by harassment.
Specific to the NARW, the estimated
amount of take, which is by Level B
harassment only (no Level A harassment
is anticipated or authorized), is seven,
or 2.07 percent of the stock abundance,
assuming that each instance of take
represents a different individual. Please
see table 3 for information relating to
this small numbers analysis.
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 would 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.
Endangered Species Act
Section 7(a)(2) of the ESA 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
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IHAs, NMFS consults internally
whenever we propose to authorize take
for endangered or threatened species, in
this case with NOAA GARFO.
There are four marine mammal
species under NMFS jurisdiction that
are listed as endangered or threatened
under the ESA that may taken, by
harassment, incidental to construction
of the project: the North Atlantic right,
sei, fin, and sperm whale. NMFS issued
a Biological Opinion on September 11,
2020, concluding that the issuance of
the 2023 Vineyard Wind IHA is not
likely to jeopardize the continued
existence of threatened and endangered
species under NMFS’ jurisdiction and is
not likely to result in the destruction or
adverse modification of designated or
proposed critical habitat. The Biological
Opinion is available at https://
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repository.library.noaa.gov/view/noaa/
37556.
The Permit and Conservation Division
requested re-initiation of section 7
consultation with GARFO on the
issuance of the Vineyard Wind
proposed IHA for Phase 2 of the
Vineyard Wind Offshore Wind Project.
NMFS will conclude the ESA
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 impact pile driving of
monopiles in the Vineyard Wind
Offshore Wind Farm offshore of
Massachusetts, provided the previously
mentioned mitigation, monitoring, and
reporting requirements are incorporated.
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A draft of the proposed IHA can be
found at: https://www.fisheries.
noaa.gov/national/marine-mammalprotection/incidental-takeauthorizations-other-energy-activitiesrenewable.
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 pile driving
activities. Please include with your
comments any supporting data or
literature citations to help inform
decisions on the request for this IHA.
Dated: April 15, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources,
National Marine Fisheries Service.
[FR Doc. 2024–08434 Filed 4–22–24; 8:45 am]
BILLING CODE 3510–22–P
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Agencies
[Federal Register Volume 89, Number 79 (Tuesday, April 23, 2024)]
[Notices]
[Pages 31008-31064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-08434]
[[Page 31007]]
Vol. 89
Tuesday,
No. 79
April 23, 2024
Part V
Department of Commerce
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National Oceanic and Atmospheric Administration
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Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to Phase 2 Construction of the Vineyard Wind
1 Offshore Wind Project Off Massachusetts; Notice
Federal Register / Vol. 89, No. 79 / Tuesday, April 23, 2024 /
Notices
[[Page 31008]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD687]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Phase 2 Construction of the
Vineyard Wind 1 Offshore Wind Project Off Massachusetts
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization.
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SUMMARY: NMFS has received a request from Vineyard Wind LLC (Vineyard
Wind) for authorization to take marine mammals incidental to the
completion of the construction of a commercial wind energy project
offshore Massachusetts in the northern portion of Lease Area OCS-A
0501. 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; which consists of a subset of activities for
which take was authorized previously, but which Vineyard Wind did not
complete within the effective dates of the previous IHA. NMFS will
consider public comments prior to making any final decision on the
issuance of the requested MMPA authorization and agency responses will
be summarized in the final notice of our decision. The IHA would be
valid for 1 year from date of issuance.
DATES: Comments and information must be received no later than May 23,
2024.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources (OPR),
NMFS and should be submitted via email to [email protected].
Electronic copies of the application and supporting documents, as well
as a list of the references cited in this document, may be obtained
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. In case of problems accessing these documents, please call
the contact listed below (see FOR FURTHER INFORMATION CONTACT).
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, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at https://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: Jessica Taylor, OPR, NMFS, (301) 427-
8401.
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 proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment. NMFS
participated as a cooperating agency on the Bureau of Ocean Energy
Management (BOEM) 2021 Environmental Impact Statement (EIS) for the
Vineyard Wind 1 Offshore Wind Project.
NMFS' proposal to issue Vineyard Wind the requested IHA constitutes
a federal action subject to NEPA (42 U.S.C. 4321 et seq.). On May 10,
2021, NMFS adopted the Bureau of Ocean Energy Management's (BOEM)
Vineyard Wind 1Final Environmental Impact Statement (FEIS), published
on March 12, 2021 and available at: https://www.boem.gov/renewable-energy/state-activities/vineyard-wind-1. NMFS is currently evaluating
if supplementation of the Vineyard Wind 1 EIS is required per 40 CFR
1502.9(d). We will review all comments submitted in response to this
notice prior to concluding our NEPA process or making a final decision
on the IHA request.
Summary of Request
On December 15, 2023, NMFS received a request from Vineyard Wind
for an IHA to take marine mammals incidental to Phase 2 construction of
the Vineyard Wind Offshore Wind Project off Massachusetts, specifically
wind turbine generator (WTG) monopile foundation installation, in the
northern portion of Lease Area OCS-A 0501. Vineyard Wind completed
installation of 47 WTG monopiles and 1 electrical service platform
(ESP) jacket foundation in 2023 under an IHA issued by NMFS on June 25,
2021 (86 FR 33810) with effective dates from May 1, 2023, through April
30, 2024. Due to unexpected delays, Vineyard Wind was not able to
complete pile driving activities before the expiration date of the
current IHA (April 30, 2024); thus, Vineyard Wind is requesting take of
marine mammals incidental to installing the remaining 15 monopiles to
complete foundation installation for the Project. In total, the Project
will consist of 62 WTG monopiles and 1 offshore substation.
Following NMFS' review of the December 2023 application, Vineyard
Wind submitted multiple revised versions of the application, and it was
deemed adequate and complete on March 13, 2024. Vineyard Wind's request
is for take of 14 species of marine mammals, by Level B harassment and,
for 6 of these species, Level A harassment. Neither Vineyard
[[Page 31009]]
Wind nor NMFS expect serious injury or mortality to result from this
activity and, therefore, an IHA is appropriate.
Vineyard Wind previously conducted high resolution geophysical
(HRG) site characterization surveys within the Lease Area and
associated export cable corridor in 2016, 2018-2021, and June-December
2023 (ESS Group Inc., 2016; Vineyard Wind 2018, 2019; EPI Group, 2021;
RPS, 2022; Vineyard Wind 2023a-f). During the 2023 construction season,
NMFS coordinated closely with Vineyard Wind to ensure compliance with
their IHA. In a few instances, NMFS raised concerns with Vineyard Wind
regarding their implementation of certain required measures. NMFS
worked closely with Vineyard Wind throughout the construction season to
course correct, where needed, and ensure compliance with the
requirements (e.g., mitigation, monitoring, and reporting) of the
previous IHA, and information regarding their monitoring results may be
found in the Estimated Take of Marine Mammals section.
Description of Proposed Activity
Overview
Vineyard Wind proposes to construct and operate an 800-megawatt
(MW) wind energy facility, the Project, in the Atlantic Ocean in Lease
area OCS-A 0501, offshore of Massachusetts. The project would consist
of up to 62 offshore wind turbine generators (WTGs), 1 electrical
service platform (ESP), an onshore substation, offshore and onshore
cabling, and onshore operations and maintenance facilities. The onshore
substation and ESP are now complete. Installation of 47 monopile
foundations was completed under a current IHA (86 FR 33810, June 25,
2021), effective from May 1, 2023, through April 30, 2024. However, due
to unexpected, Vineyard Wind will not be able to complete pile driving
activities before the expiration date of the current IHA (April 30,
2024). Take of marine mammals, in the form of behavioral harassment and
limited instances of auditory injury, may occur incidental to the
installation of the remaining 15 WTG monopile foundations due to in-
water noise exposure resulting from impact pile driving. The remaining
15 monopile foundations would occur within a Limited Installation Area
(LIA) (64.3 square kilometers (km\2\; 15,888.9 acres)) within the Lease
Area (264.4 km\2\ (65,322.4 acres)). Installation of the remaining 15
monopile foundations is expected to occur in 2024.
Dates and Duration
The proposed pile driving activities are planned to occur in 2024
after the IHA is issued and, while not planned, may occur in June or
July in 2025. Pile driving activities are estimated to require
approximately 15 nonconsecutive days (30 nonconsecutive hours of pile
driving). Given vessel availability, weather delay, and logistical
constraints, these 15 days for installation of the remaining monopile
foundations could occur close in time or spread out over months.
Although installation of a single monopile may last for several
hours, active pile driving for installation of a single monopile is
expected to last for a maximum of 2 hours. Up to 1 monopile may be
installed per day, based upon the average pile driving time (up to 2
hours) for the installation of the currently installed 47 monopiles.
Monopile foundations would be installed in batches of three to six
monopiles at a time as this represents the maximum batch size that the
installation vessel can carry to the LIA. After installation of a batch
of three to six monopiles, there would be a 4 to 7 day pause in
monopile installation to allow time for the installation vessel to
return with a new batch of monopiles. No concurrent monopile
installation is proposed. Vineyard Wind has proposed, and NMFS would
require, that pile driving activities be prohibited from January 1
through May 31 due to the increased presence of North Atlantic right
whales (NARWs) in the LIA and the timing of the project (i.e., pile
driving in May is not practicable). NMFS is also proposing to restrict
pile driving in December to the maximum extent practicable.
Specific Geographic Region
Vineyard Wind's would construct the Project in within Federal
waters off Massachusetts, in the northern portion of the Vineyard Wind
Lease Area OCS-A 0501 (figure 1). This area is also referred to as the
Wind Development Area (WDA). The 15 remaining monopiles would be
installed in a LIA within a portion of the southwest corner of the WDA.
The LIA is approximately 70.5 km\2\ (17,420.9 acres) in size, as
compared to the overall size of the Lease Area (264.4 km\2\ (63,322.4
acres)). At its nearest point, the LIA is approximately 29 kilometers
(km; 18.1 miles (mi)) from the southeast corner of Martha's Vineyard
and a similar distance from Nantucket. Water depths in the WDA range
from approximately 37 to 49.5 meters (m; 121-162 feet (ft)). Water
depth and bottom habitat are similar throughout the Lease Area (Pyc et
al., 2018).
Vineyard Wind's specified activities would occur in the Northeast
U.S. Continental Shelf Large Marine Ecosystem (NES LME), an area of
approximately 260,000 km\2\ from Cape Hatteras in the south to the Gulf
of Maine in the north. Specifically, the LIA is located within the Mid-
Atlantic Bight subarea of the NES LME, which extends between Cape
Hatteras, North Carolina, and Martha's Vineyard, Massachusetts,
extending westward into the Atlantic to the 100-m isobath. The specific
geographic region includes the LIA as well as the crew transfer vessel
transit corridors (see Proposed Mitigation section) and cable laying
routes. The installation vessel and support vessels would conduct
approximately three trips to Canada during the period of the IHA,
transiting from New Bedford and nearby ports. Figure 1 shows the LIA
and planned locations for the remaining 15 monopiles to be installed.
[[Page 31010]]
[GRAPHIC] [TIFF OMITTED] TN23AP24.040
Detailed Description of the Specified Activity
Monopile Installation
Vineyard Wind proposes to install 15 monopile WTG foundations in
the LIA (figure 1) to complete the Vineyard Wind Offshore Wind Project
(84 FR 18346, April 30, 2019; 86 FR 33810, June 25, 2021). Vineyard
Wind assumes all monopile foundations would be installed using an
impact hammer. Individual monopile installation would be sequenced
according to the numbers in the cross-hatched area in figure 1.
A WTG monopile foundation typically consists of a coated single
steel tubular section, with several sections of rolled steel plate
welded together. Each 13-MW monopile would have a maximum diameter of
9.6 m (31.5 ft). WTGs would be arranged in a grid-like pattern within
the LIA with spacing of
[[Page 31011]]
1.9 km (1 nautical mile (nmi)) between turbines, and driven to a
maximum penetration depth of 28 m (92 ft) to 35 m (115 ft) below the
seafloor (Vineyard Wind, 2023). Monopile foundations would consist of a
monopile with a separate transition piece.
Monopile foundations would be installed by a heavy lift vessel. The
installation vessel would upend the monopile with a crane and place it
in a gripper frame before lowering the monopile foundation to the
seabed (see figure 4 in IHA application). Vineyard Wind would use a
Monopile Installation Tool (MPIT) to seat the monopile foundation and
protect against pile gripper damage as well as risks to human safety
associated with pile run. The MPIT creates buoyancy within the monopile
foundation using air pressure to control lowering the monopile through
the pile run risk zone (Vineyard Wind, 2023). As the monopile
foundation is lowered, air is released from the top of the foundation
above the water surface until the pile is stabilized within the seabed.
Once the monopile is lowered to the seabed, the crane hook would be
released. A hydraulic impact hammer would be placed on top of the
monopile and used to drive the monopile into the seabed to the target
penetration depth (28-35 m). Monopile foundations would be installed
using a maximum hammer energy of 4,000 kilojoules (kJ) (table 1). Pile
driving would begin with a 20-minute soft-start at reduced hammer
energy (see Proposed Mitigation). The hammer energy would gradually be
increased based upon resistance experienced from sediments. Prior to
pile driving, the MPIT process may last from 6 to 15 hours and is
dependent upon local soil conditions at each monopile foundation
(Vineyard Wind, 2023). Vineyard Wind anticipates that one monopile
would be installed per day at a rate of approximately 2 hours of active
pile driving time per monopile (table 1). Rock scour protection would
be applied after foundation installation. The scour protection would be
1-2 m high (3-6 ft), with stone or rock sizes of approximately 10-30
centimeters (4-12 inches).
While post-piling activities could be ongoing at one foundation
position as pile driving is occurring at another position, no
concurrent/simultaneous pile driving of foundations would occur (see
Dates and Duration section). Installation of monopile foundations is
anticipated to result in the take of marine mammals due to noise
generated during pile driving. Proposed mitigation, monitoring, and
reporting measures are described in detail later in this document
(please see Proposed Mitigation and Proposed Monitoring and Reporting).
Table 1--Impact Pile Driving Schedule
----------------------------------------------------------------------------------------------------------------
Max piling Max piling
Number of time time
Pile type Project Max hammer hammer duration duration Number
component energy (kJ) strikes per pile per day piles/day
(min) (min)
----------------------------------------------------------------------------------------------------------------
9.6-m monopile............... WTG............. \a\ 4000 \b\ 2,884 117 117 1
----------------------------------------------------------------------------------------------------------------
\a\ Maximum hammer energy for representative monopiles installed during the 2023 Vineyard Wind Offshore Wind
Project construction ranged from 3,227 to 3,831 kJ.
\b\ Number of hammer strikes based upon the AU-38 representative monopile installed during the 2023 Vineyard
Wind Offshore Wind Project construction period at a maximum hammer energy of 3,825 kJ.
After monopile installation, transition pieces, containing work
platforms and other ancillary structures, and WTGs, consisting of a
tower and the energy-generating components of the turbine, would be
installed. Transition pieces and WTGs would be installed on top of
monopile foundations using jack-up vessels. However, installation of
transition pieces and WTGS on monopile foundations is not expected to
result in take of marine mammals and, therefore, are not discussed
further.
Vineyard Wind has developed a sequencing plan for installation of
monopiles throughout the LIA, as shown in figure 1. The sequencing plan
will allow for several of the monopiles located in the northeast corner
of the LIA and highest density area of NARWs, to be installed first.
Vineyard Wind anticipates that it is possible for the 15 WTGs to
become operational within the effective period of the IHA. Nine of the
47 WTGs previously installed in 2023 are currently operational.
Vessel Operation
Vineyard Wind would use various types of vessels over the course of
the 1-year proposed IHA for foundation installation and transporting
monopile batches between ports and the LIA (table 2). Construction-
related vessel activity is anticipated to include approximately 20
vessels operating throughout the specified geographic area on any given
work day. Many of these vessels would remain in the LIA for days or
weeks at a time, making infrequent trips to port for bunkering and
provisioning, as needed. Table 2 shows the type and number of vessels
Vineyard Wind would use for various construction activities as well as
the associated ports. Vineyard Wind would utilize ports in New London,
Connecticut and New Bedford, Massachusetts (table 2) to support
offshore construction, crew transfer and logistics, and other
operational activities. In addition, monopile foundations would come
from a Canadian port in Halifax. Monopile foundations would be
transported on an installation vessel to the LIA from Canada, and would
be installed in batches of three to six monopiles at a time. Upon
completion of installation of a batch of monopiles, the installation
vessel would return to Canada to load an additional batch of monopiles
(Vineyard Wind, 2023). For the proposed activities, it is expected that
the installation vessel would need to make a maximum of three trips
between Canada and the LIA.
As part of vessel-based construction activities, dynamic
positioning thrusters would be utilized to hold vessels in position or
move slowly during monopile installation. Sound produced through use of
dynamic positioning thrusters is similar to that produced by transiting
vessels, and dynamic positioning thrusters are typically operated
either in a similarly predictable manner or used for short durations
around stationary activities. Construction-related vessel activity,
including the use of dynamic positioning thrusters, is not expected to
result in take of marine mammals. While a vessel strike could cause
injury or mortality of a marine mammal, Vineyard Wind proposed and NMFS
is proposing to require, extensive vessel strike avoidance measures
that would avoid vessel strikes from occurring (see Proposed Mitigation
and Proposed Monitoring and Reporting). Vineyard Wind did not request,
and NMFS
[[Page 31012]]
neither anticipates nor proposes to authorize, take associated with
vessel activity, and this activity is not analyzed further.
Table 2--Type and Number of Vessels Anticipated During Construction
----------------------------------------------------------------------------------------------------------------
Expected
Maximum number maximum number
Vessel type Vessel role of vessels of transits Port
per month
----------------------------------------------------------------------------------------------------------------
Heavy lift vessel................. Pile driving......... 1 2 Halifax, Canada.
Trans-shipment vessel............. Bubble curtain....... 2 4 New London, CT.
Fishing vessel.................... PSO support vessel... 2 3 New Bedford, MA.
Service operations 1 4
vessel.
Safety vessel........ 4 2
Motor vessel...................... Crew transfer vessel. 2 12
----------------------------------------------------------------------------------------------------------------
Inter-Array Cable Laying
Inter-array cables would be installed to connect WTGs to the ESP.
In 2023, Vineyard Wind completed approximately 40 percent of the
installation of inter-array cables in the Lease Area. Vineyard Wind
anticipates approximately 50 percent of the inter-array cable laying to
take place during the effective period of the IHA. Vineyard Wind would
perform a pre-lay grapnel run to remove any obstructions, such as
fishing gear, from the seafloor. The cable would be laid on the
seafloor and buried using a jet trencher with scour added for cable
protection near the transition pieces and ESPs. The sounds associated
with cable laying are consistent with those of routine vessel
operations and not expected to result in take of marine mammals. Inter-
array cable laying activities are, therefore, not discussed further.
Other Activities
Vineyard Wind would not conduct high-resolution geophysical (HRG)
surveys, UXO/MEC detonation, or fishery research surveys under this
IHA.
Description of Marine Mammals in the Area of Specified Activities
Thirty-eight marine mammal species, comprising 39 stocks, under
NMFS' jurisdiction have geographic ranges within the western North
Atlantic OCS (Hayes et al., 2023). However, for reasons described
below, Vineyard Wind has requested, and NMFS proposes to authorize,
take of only 14 species (comprising 14 stocks) of marine mammals.
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, instead of reprinting the information. See
ADDRESSES. Additional information regarding population trends and
threats may be found in NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS'
website (https://www.fisheries.noaa.gov/find-species).
Table 3 lists all species or stocks for which take is expected and
proposed to be authorized for this activity and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. 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'
SARs; 16 U.S.C. 1362(20)). While no serious injury or mortality is
anticipated or proposed to be authorized here, PBR and annual serious
injury and mortality from anthropogenic sources are included here as
gross indicators of the status of the species or stocks and other
threats. Four of the marine mammal species for which take is requested
are listed as endangered under the ESA, including the NARW, fin whale,
sei whale, and sperm whale.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprise 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. 2023 draft SARs and NMFS' U.S. 2022 SARs. For the majority
of species potentially present in the specific geographic region, NMFS
has designated only a single generic stock (e.g., ``western North
Atlantic'') for management purposes. This includes the ``Canadian east
coast'' stock of minke whales, which includes all minke whales found in
United States waters and is also a generic stock for management
purposes. For humpback and sei whales, NMFS defines stocks on the basis
of feeding locations (i.e., Gulf of Maine and Nova Scotia,
respectively). However, references to humpback whales and sei whales in
this document refer to any individuals of the species that are found in
the specific geographic region. All values presented in table 3 are the
most recent available at the time of publication and are available
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.
[[Page 31013]]
Table 3--Marine Mammal Species That May Occur in the LIA and Be Taken by Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA Stock abundance (CV,
status; Nmin, most recent Annual M/SI
Common name \a\ Scientific name Stock strategic (Y/N) abundance survey) PBR \d\
\b\ \c\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
NARW......................... Eubalaena glacialis............ Western Atlantic.... E, D, Y 340 (0; 337; 2021) 0.7 27.2 \f\
\e\.
Family Balaenopteridae
(rorquals):
Fin whale.................... Balaenoptera physalus.......... Western North E, D, Y 6,802 (0.24, 5,573, 11 2.05
Atlantic. 2021).
Sei whale.................... Balaenoptera borealis.......... Nova Scotia......... E, D, Y 6,292 (1.02, 3098, 6.2 0.6
2021).
Minke whale.................. Balaenoptera acutorostrata..... Canadian Eastern -, -, N 21,968 (0.31, 170 9.4
Coastal. 17,002, 2021).
Humpback whale............... Megaptera novaeangliae......... Gulf of Maine....... -, -, Y 1,396 (0, 1,380, 22 12.15
2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
Sperm whale.................. Physeter macrocephalus......... North Atlantic...... E, D, Y 5,895 (0.29, 4,639, 9.28 0.2
2021).
Family Delphinidae:
Long-finned pilot whale...... Globicephala melas............. Western North -, -, N 39,215 (0.3, 30,627, 306 5.7
Atlantic. 2021).
Bottlenose dolphin........... Tursiops truncatus............. Western North -, -, N 64,587 (0.24, 507 28
Atlantic Offshore. 52,801, 2021) \g\.
Common dolphin............... Delphinus delphis.............. Western North -, -, N 93,100 (0.56, 1,452 414
Atlantic. 59,897, 2021).
Risso's dolphin.............. Grampus griseus................ Western North -, -, N 44,067 (0.19, 307 18
Atlantic. 30,662, 2021).
Atlantic white-sided dolphin. Lagenorhynchus acutus.......... Western North -, -, N 93,233 (0.71, 544 28
Atlantic. 54,443, 2021).
Family Phocoenidae (porpoises):
Harbor porpoise.............. Phocoena phocoena.............. Gulf of Maine/Bay of -, -, N 85,765 (0.53, 649 145
Fundy. 56,420, 2021).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Harbor seal.................. Phoca vitulina................. Western North -, -, N 61,336 (0.08, 1,729 339
Atlantic. 57,637, 2018).
Gray seal \h\................ Halichoerus grypus............. Western North -, -, N 27,911 (0.2, 23,924, 1,512 4,570
Atlantic. 2021).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies; Committee on Taxonomy, 2023).
\b\ 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.
\c\ NMFS 2022 marine mammal SARs online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV is the
coefficient of variation; Nmin is the minimum estimate of stock abundance.
\d\ 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).
\e\ The draft 2023 SAR includes an estimated population (Nbest 340) based on sighting history through December 2021 (89 FR 5495, January 29, 2024). In
October 2023, NMFS released a technical report identifying that the NARW population size based on sighting history through 2022 was 356 whales, with a
95 percent credible interval ranging from 346 to 363 (Linden, 2023).
\f\ Total annual average observed NARW mortality during the period 2017-2021 was 7.1 animals and annual average observed fishery mortality was 4.6
animals. Numbers presented in this table (27.2 total mortality and 17.6 fishery mortality) are 2016-2020 estimated annual means, accounting for
undetected mortality and serious injury.
\g\ As noted in the draft 2023 SAR (89 FR 5495, January 29, 2024), abundance estimates may include sightings of the coastal form.
\h\ NMFS' stock abundance estimate (and associated PBR value) applies to the U.S. population only. Total stock abundance (including animals in Canada)
is approximately 394,311. The annual M/SI value given is for the total stock.
As indicated above, all 14 species (with 14 managed stocks) in
table 3 temporally and spatially co-occur with the activity to the
degree that take is expected to occur. The following species are not
expected to occur in the LIA due to their known distributions,
preferred habitats, and/or known temporal and spatial occurrences: the
blue whale (Balaenoptera musculus), northern bottlenose whale
(Hyperoodon ampullatus), false killer whale (Pseudorca crassidens),
pygmy killer whale (Feresa attenuata), melon-headed whale
(Peponocephala electra), dwarf and pygmy sperm whales (Kogia spp.),
killer whale (Orcinus orca), Cuvier's beaked whale (Ziphius
cavirostris), four species of Mesoplodont whale (Mesoplodon
densitostris, M. europaeus, M. mirus, and M. bidens), Fraser's dolphin
(Lagenodelphis hosei), Clymene dolphin (Stenella clymene), spinner
dolphin (Stenella longirostris), rough-toothed dolphin (Steno
bredanensis), Atlantic spotted dolphin (Stenella frontalis),
pantropical spotted dolphin (Stenella attenuata), short-finned pilot
whale (Globicephala macrorhynchus), striped dolphin (Stenella
coeruleoalba), white-beaked dolphin (Lagenorhynchus albirostris), and
hooded seal (Crysophora cristata). None of these species were observed
during the 2023 construction season or during previous site assessment/
characterization surveys (Vineyard Wind, 2018, 2019, 2023a-f). Due to
the lack of sightings of these species in the MA Wind Energy Area (WEA)
(Kenney and Vigness-Raposa, 2010; ESS Group, Inc., 2016; Kraus et al.,
2016; Vineyard Wind, 2018; 2019; O'Brien et al., 2020, 2021, 2022,
2023; EPI Group, 2021; Palka et al., 2017 2021; RPS, 2022; Vineyard
Wind, 2023a-f; Hayes et al., 2023) as well as documented habitat
preferences and distributions, we have determined that
[[Page 31014]]
each of these species will not be considered further. Furthermore, the
northern limit of the northern migratory coastal stock of the common
bottlenose dolphin (Tursiops truncatus) does not extend as far north as
the LIA. Thus, take is only proposed for the offshore stock which may
occur within the LIA. Although harp seals (Pagophilus groenlandicus)
are expected to occur within the WDA, no harp seals were observed by
Protected Species Observers (PSOs) during Vineyard Wind's site
characterization surveys (2016, 2018-2021; ESS Group, Inc., 2016;
Vineyard Wind, 2018, 2019) nor during the 2023 construction campaign
(Vineyard Wind, 2023a-f). Thus, Vineyard Wind did not request, and NMFS
is not proposing to authorize, take for this species.
In addition to what is included in sections 3 and 4 of Vineyard
Wind's ITA application (Vineyard Wind, 2023), the SARs (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments), and NMFS' website (https://www.fisheries.noaa.gov/species-directory/marine-mammals), we provide further detail below
informing the baseline for select species (e.g., information regarding
current unusual mortality events (UMEs) and known important habitat
areas, such as biologically important areas (BIAs; https://oceannoise.noaa.gov/biologically-important-areas) (Van Parijs, 2015)).
There are no ESA-designated critical habitats for any species within
the LIA (https://www.fisheries.noaa.gov/resource/map/national-esa-critical-habitat-mapper). Any areas of known biological importance
(including the BIAs identified in LaBrecque et al., 2015) that overlap
spatially (or are adjacent) with the LIA are addressed in the species
sections below.
Under the MMPA, a UME is defined as ``a stranding that is
unexpected; involves a significant die-off of any marine mammal
population; and demands immediate response'' (16 U.S.C. 1421h(6)). As
of January 2024, three UMEs are occurring along the U.S. Atlantic coast
for NARWs, humpback whales, and minke whales. Of these, the most
relevant to the LIA are the NARW and humpback whale UMEs given the
prevalence of these species in Southern New England (SNE). Below, we
include information for a subset of the species that presently have an
active or recently closed UME occurring along the Atlantic coast or for
which there is information available related to areas of biological
significance. More information on UMEs, including all active, closed,
or pending, can be found on NMFS' website at https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events.
North Atlantic Right Whale
The NARW has been listed as Endangered since the ESA's enactment in
1973. The species was recently uplisted from Endangered to Critically
Endangered on the International Union for Conservation of Nature Red
List of Threatened Species (Cooke, 2020). The uplisting was due to a
decrease in population size (Pace et al., 2017), an increase in vessel
strikes and entanglements in fixed fishing gear (Daoust et al., 2017;
Davis & Brillant, 2019; Knowlton et al., 2012; Knowlton et al., 2022;
Moore et al., 2021; Sharp et al., 2019), and a decrease in birth rate
(Pettis et al., 2022; Reed et al., 2022). The western Atlantic stock is
considered depleted under the MMPA (Hayes et al., 2023). There is a
recovery plan (NMFS, 2005) for the NARW, and NMFS completed 5-year
reviews of the species in 2012, 2017, and 2022, which concluded no
change to the listing status is warranted.
The NARW population had only a 2.8-percent recovery rate between
1990 and 2011 and an overall abundance decline of 23.5 percent from
2011 to 2019 (Hayes et al., 2023). Since 2011, the NARW population has
been in decline; however, the sharp decrease observed from 2015 to 2020
appears to have slowed, though the right whale population continues to
experience annual mortalities above recovery thresholds (Pace et al.,
2017; Pace et al., 2021; Linden, 2023). NARW calving rates dropped from
2017 to 2020 with zero births recorded during the 2017-2018 season. The
2020-2021 calving season had the first substantial calving increase in
5 years with 20 calves born (including 2 mortalities) followed by 15
calves during the 2021-2022 calving season and 12 births (including 1
mortality) in 2022-2023 calving season. These data demonstrate that
birth rates are increasing. However, mortalities continue to outpace
births (Linden, 2023). Best estimates indicate fewer than 70
reproductively active females remain in the population and adult
females experience a lower average survival rate than males (Linden,
2023). In 2023, the total annual average observed NARW mortality
increased from 8.1 (which represents 2016-2020) to 31.2 (which
represents 2015-2019), however, this updated estimate also accounts for
undetected mortality and serious injury (Hayes et al., 2023). Although
the predicted number of deaths from the population are lower in recent
years (2021-2022) when compared to the high number of deaths from 2014
to 2020, suggesting a short-term increase in survival, annual mortality
rates still exceed PBR (Linden, 2023).
NMFS' regulations at 50 CFR 224.105 designated Seasonal Management
Areas (SMAs) for NARWs in 2008 (73 FR 60173, October 10, 2008). SMAs
were developed to reduce the threat of collisions between vessels and
NARWs. A portion of the Block Island SMA, which occurs off Block
Island, Rhode Island, is near the LIA (approximately 4.3 km (2.7 mi)
southwest of the OCS-A 0501 Lease Area at the closest point), but does
not overlap spatially with the Lease Area or LIA. This SMA is active
from November 1 through April 30 of each year, and may be used by NARWs
for migrating and/or feeding. As noted below, NMFS is proposing changes
to the NARW speed rule (87 FR 46921, August 1, 2022). NMFS has
designated critical habitat for NARWs (81 FR 4838, January 27, 2016),
along the U.S. southeast coast for calving as well as in the northeast,
just east of the LIA. The LIA both spatially and temporally overlaps a
portion of a migratory corridor BIA (LaBrecque et al., 2015). Due to
the current status of NARWs and the spatial proximity of the proposed
project with areas of biological significance, (i.e., a migratory
corridor, SMA), the potential impacts of the proposed project on NARWs
warrant particular attention.
NARWs range from calving grounds in the southeastern United States
to feeding grounds in New England waters and into Canadian waters
(Hayes et al., 2023). Surveys have demonstrated the existence of seven
areas where NARWs congregate seasonally in Georges Bank, off Cape Cod,
and in Massachusetts Bay (Hayes et al., 2023). In late fall (i.e.,
November), a portion of the NARW population (including pregnant
females) typically departs the feeding grounds in the North Atlantic,
moves south along the migratory corridor BIA, including through the
LIA, to calving grounds off Georgia and Florida. This movement is
followed by a northward migration (primarily mothers with young calves)
into northern feeding areas in March and April (LaBrecque et al., 2015;
Van Parijs, 2015). Recent research indicates our understanding of their
movement patterns remains incomplete and not all of the population
undergoes a consistent annual migration (Davis et al., 2017; Gowan et
al., 2019; Krzystan et al., 2018). Non-calving females may remain in
the feeding grounds during the winter in the years preceding and
following the
[[Page 31015]]
birth of a calf to increase their energy stores (Gowen et al., 2019).
NARWs may migrate through the LIA to access more northern feeding
grounds or southern calving grounds.
NARWs may occur year-round in SNE, near Martha's Vineyard and
Nantucket Shoals as well as throughout the Massachusetts and Rhode
Island/Massachusetts Wind Energy Areas (MA and RI/MA WEAs) (Quintan-
Rizzo et al., 2021; O'Brien et al., 2023; Van Parijs et al., 2023).
Kraus et al. (2016) found acoustic detections in SNE to peak during the
winter and early spring (January through March). Visual surveys
(Quintana-Rizzo et al., 2021) have also confirmed the abundance of
NARWs in SNE to be the highest during the winter and spring (January
through May), although peaks in acoustic detections may vary seasonally
across years (Quintana-Rizzo et al., 2021; Estabrook et al., 2022).
Distribution throughout SNE may vary seasonally with NARW occurrence
being closest to the LIA during the spring (Quintana-Rizzo et al.,
2021). Van Parijs et al. (2023) monitored acoustic detections of baleen
whales throughout SNE and detected NARWs near the LIA from January
through May. Acoustic detections began to increase near the LIA in
November and further increased into December (Van Parijs et al., 2023).
An 8-year analysis of NARW sightings within SNE showed that the
NARW distribution has been shifting (Quintana-Rizzo et al., 2021).
NARWs feed primarily on the copepod, Calanus finmarchicus, a species
whose availability and distribution has changed both spatially and
temporally over the last decade due to an oceanographic regime shift
that has been ultimately linked to climate change (Meyer-Gutbrod et
al., 2021; Record et al., 2019; Sorochan et al., 2019). This
distribution change in prey availability has led to shifts in NARW
habitat-use patterns over the same time period (Davis et al., 2020;
Meyer-Gutbrod et al., 2022; Quintano-Rizzo et al., 2021; O'Brien et
al., 2022; Pendleton et al., 2022; Van Parijs et al., 2023), with
reduced use of foraging habitats in the Great South Channel and Bay of
Fundy and increased use of habitats within Cape Cod Bay and a region
south of Martha's Vineyard and Nantucket Islands (Stone et al., 2017;
Mayo et al., 2018; Ganley et al., 2019; Record et al., 2019; Meyer-
Gutbrod et al., 2021; Van Parijs et al., 2023). Pendleton et al. (2022)
observed shifts in the timing of NARW peak habitat use in Cape Cod Bay
during the spring, likely in response to changing seasonal conditions,
and characterized SNE as a ``waiting room'' for NARWs in the spring,
providing sufficient, although sub-optimal, prey choices while the
NARWs wait for foraging conditions in Cape Cod Bay (and other primary
foraging grounds such as the Great South Channel) to optimize as
seasonal primary and secondary production progresses.
While Nantucket Shoals is not designated as critical NARW habitat,
its importance as a foraging habitat is well established (Leiter et
al., 2017; Quintana-Rizzo et al., 2021; Estabrook et al., 2022; O'Brien
et al., 2022). Nantucket Shoals' unique oceanographic and bathymetric
features, including a persistent tidal front, help sustain year-round
elevated phytoplankton biomass, and aggregate zooplankton prey for
NARWs (Quintana-Rizzo et al., 2021). SNE serves as a foraging habitat
throughout the year, although not to the extent provided seasonally in
more well-understood feeding habitats like Cape Cod Bay in late spring,
the Great South Channel, and the Gulf of St. Lawrence (O'Brien et al.,
2022). A BIA for foraging (LaBrecque et al., 2015) within Cape Cod Bay
is approximately 71 km (44.1 mi) north of the LIA, while critical
habitat northeast of Martha's Vineyard and Nantucket Island is within
56 km (34.8 mi). SNE also represents socializing habitat for NARWs as
Leiter et al. (2017) documented surface active groups (SAGs),
indicative of socializing behavior, year-round in SNE.
Observations of NARW transitions in habitat use, variability in
seasonal presence in identified core habitats, and utilization of
habitat outside of previously focused survey effort prompted the
formation of a NMFS' Expert Working Group, which identified current
data collection efforts, data gaps, and provided recommendations for
future survey and research efforts (Oleson et al., 2020). In addition,
extensive data gaps that were highlighted in a recent report by the
National Academy of Sciences (NAS, 2023) have prevented development of
a thorough understanding of NARW foraging ecology in the Nantucket
Shoals region. However, it is clear that the habitat was historically
valuable to the species, given that the whaling industry capitalized on
consistent NARW occurrence there, and has again become increasingly so
over the last decade.
Since 2017, 125 dead, seriously injured, or sublethally injured or
ill NARWs along the United States and Canadian coasts have been
documented, necessitating a UME declaration in 2017 and subsequent
investigation. The leading category for the cause of death for this
ongoing UME is ``human interaction,'' specifically from entanglements
or vessel strikes. As of April 9, 2024, there have been 39 confirmed
mortalities, 1 pending mortality (dead, stranded, or floaters), and 34
seriously injured free-swimming whales for a total of 73 whales.
Beginning on October 14, 2022, the UME also considers animals with
sublethal injury or illness bringing the total number of whales in the
UME to 125. Approximately 42 percent of the population is known to be
in reduced health (Hamilton et al., 2021) likely contributing to
smaller body sizes at maturation, making them more susceptible to
threats and reducing fecundity (Moore et al., 2021; Reed et al., 2022;
Stewart et al., 2022; Pirotta et al., 2024). Pirotta et al. (2024)
found an association between the decreased mean length of female NARWs
and reduced calving probability. More information about the NARW UME is
available online at https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2024-north-atlantic-right-whale-unusual-mortality-event.
On August 1, 2022, NMFS announced proposed changes to the existing
NARW vessel speed regulations to further reduce the likelihood of
mortalities and serious injuries to endangered right whales from vessel
collisions, which are a leading cause of the species' decline and a
primary factor in the ongoing Unusual Mortality Event (87 FR 46921,
August 1, 2022). Should a final vessel speed rule be issued and become
effective during the effective period of this IHA (or any other MMPA
incidental take authorization), the authorization holder would be
required to comply with any and all applicable requirements contained
within the final rule. Specifically, where measures in any final vessel
speed rule are more protective or restrictive than those in this or any
other MMPA authorization, authorization holders would be required to
comply with the requirements of the rule. Alternatively, where measures
in this or any other MMPA authorization are more restrictive or
protective than those in any final vessel speed rule, the measures in
the MMPA authorization would remain in place. These changes would
become effective immediately upon the effective date of any final
vessel speed rule and would not require any further action on NMFS's
part.
Humpback Whale
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
[[Page 31016]]
be listed as endangered. On September 8, 2016, NMFS divided the once
single species into 14 distinct population segments (DPS), removed the
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 whales that is
expected to occur in the LIA. Bettridge et al. (2015) estimated the
size of the West Indies DPS population at 12,312 (95 percent confidence
interval 8,688-15,954) whales in 2004-2005, which is consistent with
previous population estimates of approximately 10,000-11,000 whales
(Stevick et al., 2003; Smith et al., 1999) and the increasing trend for
the West Indies DPS (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 been sighted repeatedly
within the same winter season, indicating that not all humpback whales
migrate south every winter (Hayes et al., 2018).
Kraus et al. (2016) conducted aerial surveys from 2011-2015 in SNE
and observed humpback whales during all seasons, yet humpback whales
were observed most often during the spring and summer. The greatest
number of sightings occurred during the month of April (n=33) (Kraus et
al., 2016). Calves, feeding behavior, and courtship behavior were
observed as well. More recent studies (O'Brien et al., 2020, 2021,
2022, 2023) confirm that humpback whales peak in abundance in the LIA
during spring and summer, with the majority of sightings year-round
occurring in the eastern portion of the MA and RI/MA WEAs and near the
Nantucket Shoals area (O'Brien et al., 2020). O'Brien et al. (2022)
identified seasonal distribution patterns of humpback whales throughout
SNE with more concentrated sightings near Nantucket Shoals in the fall
and sightings being distributed more evenly across the MA and RI/MA
WEAs during spring and summer. As observed during the 2011-2015
surveys, O'Brien et al. (2023) also observed feeding behavior and
mother/calf pairs throughout the spring and summer. Van Parijs et al.
(2023) detected humpback whales near the LIA mainly from November
through June. During the Vineyard Wind 2023 construction campaign,
visual and acoustic detections of humpback whales occurred mainly from
June through October, with the greatest detections occuring in October
(Vineyard Wind, 2023).
The LIA does not overlap with any BIAs or other important areas for
the humpback whales. A humpback whale feeding BIA extends throughout
the Gulf of Maine, Stellwagen Bank, and Great South Channel from May
through December, annually (LaBrecque et al., 2015). This BIA is
located approximately 73 km (45.5 mi) northeast of the Lease Area and
would not likely be impacted by project activities.
Since January 2016, elevated humpback whale mortalities along the
Atlantic coast from Maine to Florida led to the declaration of a UME in
April 2017. As of April 9, 2024, 218 humpback whales have stranded as
part of this UME. Partial or full necropsy examinations have been
conducted on approximately 90 of the known cases. Of the whales
examined, about 40 percent had evidence of human interaction, either
ship strike or entanglement. While a portion of the whales have shown
evidence of pre-mortem vessel strike, this finding is not consistent
across all whales examined and more research is needed. Since January
1, 2023, 43 humpbacks have stranded along the east coast of the United
States (7 of these whales have stranded off Massachusetts). These
whales may have been following their prey (small fish) which were
reportedly close to shore this past winter. These prey also attract
fish that are targeted by recreational and commercial fishermen, which
increases the number of boats in these areas. More information is
available at https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events.
Fin Whale
Fin whales frequently occur in the waters of the U.S. Atlantic
Exclusive Economic Zone (EEZ), principally from Cape Hatteras, North
Carolina northward and are distributed in both continental shelf and
deep-water habitats (Hayes et al., 2023). Although fin whales are
present north of the 35-degree latitude north region in every season
and are broadly distributed throughout the western North Atlantic for
most of the year, densities vary seasonally (Edwards et al., 2015;
Hayes et al., 2023). Fin whales typically feed in the Gulf of Maine and
the waters surrounding New England, but their mating and calving (and
general wintering) areas are largely unknown (Hain et al., 1992; Hayes
et al., 2023). 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., 2022).
New England waters represent a major feeding ground for fin whales,
and fin whale feeding BIAs occur offshore of Montauk Point, New York,
from March to October (2,933 km\2\) (Hain et al., 1992; LaBrecque et
al., 2015) and year-round in the southern Gulf of Maine (18,015 km\2\).
Aerial surveys conducted from 2011-2015 in SNE documented fin whale
occurrence in every season, with the greatest numbers of sightings
during the spring (n=35) and summer (n=49) months (Kraus et al., 2016).
Fin whale distribution varied seasonally, with fin whales occurring in
the southern regions of the MA and RI/MA WEAs during spring and closer
to northern regions of the WEAs during summer (Kraus et al., 2016).
More recent surveys have documented fin whales throughout winter,
spring, and summer (O'Brien et al., 2020, 2021, 2022, 2023) with the
greatest abundance occurring during the summer and clustered in the
western portion of the WEAs (O'Brien et al., 2023). Acoustic detection
of fin whales in SNE indicate fin whale presence in the area from
August through April and, sporadically, from May through July (Parijs
et al., 2023). During the 2023 construction campaign, Vineyard Wind
detected fin whales from June through December (with the exception of
August), with the most detections occurring in October (Vineyard Wind,
2023). Based upon observations of feeding behavior and the close
proximity of the Lease Area to the
[[Page 31017]]
feeding BIAs (8.0 km (5.0 mi) and 76.4 km (47.5 mi) to the Montauk
Point and southern Gulf of Maine BIAs, respectively) fin whales may use
the LIA for foraging as well as migrating.
Minke Whale
Minke whales are common and widely distributed throughout the U.S.
Atlantic EEZ (Cetacean and Turtle Assessment Program (CETAP), 1982;
Hayes et al., 2022), although their distribution has a strong seasonal
component. Individuals have often been detected acoustically in shelf
waters from spring to fall and more often detected in deeper offshore
waters from winter to spring (Risch et al., 2013). Minke whales are
abundant in New England waters from May through September (Pittman et
al., 2006; Waring et al., 2014), yet largely absent from these areas
during the winter, suggesting the possible existence of a migratory
corridor (LaBrecque et al., 2015). A migratory route for minke whales
transiting between northern feeding grounds and southern breeding areas
may exist to the east of the LIA, as minke whales may track warmer
waters along the continental shelf while migrating (Risch et al.,
2014). Risch et al. (2014) suggests the presence of a minke whale
breeding ground offshore of the southeastern US during the winter.
There are two minke whale feeding BIAs identified in the southern
and southwestern section of the Gulf of Maine, including Georges Bank,
the Great South Channel, Cape Cod Bay and Massachusetts Bay, Stellwagen
Bank, Cape Anne, and Jeffreys Ledge from March through November,
annually (LaBrecque et al., 2015). The nearest BIA is approximately
44.0 km (27.3 mi) northeast of the Lease Area. Due to the close
proximity of the BIA, minke whale feeding may occur within the LIA.
Although minke whales are sighted in every season in SNE (O'Brien
et al., 2022), minke whale use of the area is highest during the months
of March through September (Kraus et al., 2016; O'Brien et al., 2023).
Large feeding aggregations of humpback, fin, and minke whales have been
observed during the summer (O'Brien et al., 2023), suggesting the LIA
may serve as a supplemental feeding grounds for these species. Acoustic
detections data support visual sighting data, and indicate minke whale
presence in SNE from March through June and August through late
November/early December and, sporadically, in January (Parijs et al.,
2023). During the 2023 construction campaign, Vineyard Wind detected
minke whales from June through August (Vineyard Wind, 2023).
From 2017 through 2024, elevated minke whale mortalities detected
along the Atlantic coast from Maine through South Carolina resulted in
the declaration of a UME in 2018. As of April 9, 2024, a total of 166
minke whale mortalities have occurred during this UME. Full or partial
necropsy examinations were conducted on more than 60 percent of the
whales. Preliminary findings in several of the whales have shown
evidence of human interactions or infectious disease, but these
findings are not consistent across all of the minke whales examined, so
more research is needed. More information is available at https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast.
Sei Whale
The Nova Scotia stock of sei whales can be found in deeper waters
of the continental shelf edge of the eastern United States and
northeastward to south of Newfoundland (Mitchell, 1975; Hain et al.,
1985; Hayes et al., 2022). During spring and summer, the stock is
mainly concentrated in northern feeding areas, including the Scotian
Shelf (Mitchell and Chapman, 1977), the Gulf of Maine, Georges Bank,
the Northeast Channel, and south of Nantucket (CETAP, 1982; Kraus et
al., 2016; Roberts et al., 2016; Palka et al., 2017; Cholewiak et al.,
2018; Hayes et al., 2022). Sei whales have been detected acoustically
along the Atlantic Continental Shelf and Slope from south of Cape
Hatteras, North Carolina to the Davis Strait, with acoustic occurrence
increasing in the mid-Atlantic region since 2010 (Davis et al., 2020).
Sei whale migratory movements are not well understood. In June and
July, sei whales are believed to migrate north from SNE to feeding
areas in eastern Canada, and south in September and October to breeding
areas (Mitchell, 1975; CETAP, 1982; Davis et al., 2020). Sei whales
generally occur offshore; however, individuals may also move into
shallower, more inshore waters (Payne et al., 1990; Halpin et al.,
2009; Hayes et al., 2022). A sei whale feeding BIA occurs in New
England waters from May through November, approximately 101.4 km (63
mi) east of the LIA (LaBrecque et al., 2015).
Aerial surveys conducted from 2011-2015 in SNE observed sei whales
between March and June, with the greatest number of sightings occurring
in May (n=8) and June (n=13), and no sightings from July through
January (Kraus et al., 2016). Acoustic detections confirm peak
occurrences of sei whales in SNE from early spring and through mid-
summer (March through July) (Davis et al., 2020). In addition, Van
Parijs et al. (2023) acoustically detected sei whales near the LIA
during the months of February and August. However, Davis et al. (2020)
acoustically detected sei whales in SNE year-round, suggesting this
area is an important habitat for sei whales. As sei whales are known to
target the prey such as copepods (C. finmarchicus), which are abundant
in SNE waters (Quintana-Rizzo et al., 2018), SNE likely represents a
supplemental foraging area for sei whales as well.
Phocid Seals
Harbor and gray seals have experienced multiple UMEs since 2018.
From June through July 2022, elevated numbers of harbor seal and gray
seal mortalities occurred across the southern and central coast of
Maine. This event was declared a UME. During the event, 181 seals
stranded. Based upon necropsy, histopathology, and diagnostic findings,
this UME was attributed to spillover events of the highly pathogenic
avian influenza from infected birds to harbor and gray seals. While the
UME did not occur in the LIA, the populations that were affected by the
UME are the same as those potentially affected by the project. This UME
has recently been closed. Information on this UME is available online
at https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast.
The above event was preceded by a different UME, occurring from
2018 to 2020 (closure of the 2018-2020 UME is pending). Beginning in
July 2018, elevated numbers of harbor seal and gray seal mortalities
occurred across Maine, New Hampshire, and Massachusetts. Additionally,
stranded seals have shown clinical signs as far south as Virginia,
although not in elevated numbers, therefore the UME investigation
encompassed all seal strandings from Maine to Virginia. A total of
3,152 reported strandings (of all species) occurred from July 1, 2018,
through March 13, 2020. Full or partial necropsy examinations have been
conducted on some of the seals and samples have been collected for
testing. Based on tests conducted thus far, the main pathogen found in
the seals is phocine distemper virus. NMFS is performing additional
testing to identify any other factors that may be involved
[[Page 31018]]
in this UME, which is pending closure. Information on this UME is
available online at: https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along.
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. 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, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). 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-
decibel (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 4.
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
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 the ~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
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al.,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals 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 of Marine Mammals 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 whether those impacts are reasonably expected to, or reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival.
Vineyard Wind has requested, and NMFS proposes to authorize, the
take of marine mammals incidental to the construction activities
associated with the LIA. In their application, Vineyard Wind presented
their analyses of potential impacts to marine mammals from the acoustic
sources. NMFS carefully reviewed the information provided by Vineyard
Wind, as well as independently reviewed applicable scientific research
and literature and other information to evaluate the potential effects
of the Project's activities on marine mammals.
The proposed activities would result in the construction and
placement of 15 permanent foundations to support WTGs. There are a
variety of types and degrees of effects to marine mammals, prey
species, and habitat that could occur as a result of the Project. Below
we provide a brief description of the types of sound sources that would
be generated by the project, the general impacts from these types of
activities, and an analysis of the anticipated impacts on marine
mammals from the project, with consideration of the proposed mitigation
measures.
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: Au and Hastings, 2008; Richardson et al., 1995; Urick,
1983; as well as the Discovery of Sound in the Sea (DOSITS) website at
https://www.dosits.org. Sound is a vibration that travels as an
acoustic wave through a medium such as a gas, liquid, or solid. Sound
waves alternately compress and decompress the medium as the wave
travels. These compressions and decompressions are detected as changes
in pressure by aquatic life and man-made sound receptors such as
hydrophones (underwater microphones). In water, sound waves radiate in
a manner similar to ripples on the surface of a pond and may be either
directed in a beam (narrow beam or directional sources) or sound beams
may radiate in all directions (omnidirectional sources).
Sound travels in water more efficiently than almost any other form
of energy, making the use of acoustics ideal for the aquatic
environment and its inhabitants. In seawater, sound
[[Page 31019]]
travels at roughly 1,500 meters per second (m/s). In-air, sound waves
travel much more slowly, at about 340 m/s. However, the speed of sound
can vary by a small amount based on characteristics of the transmission
medium, such as water temperature and salinity. Sound travels in water
more efficiently than almost any other form of energy, making the use
of acoustics ideal for the aquatic environment and its inhabitants. In
seawater, sound travels at roughly 1,500 m/s. In-air, sound waves
travel much more slowly, at about 340 m/s. However, the speed of sound
can vary by a small amount based on characteristics of the transmission
medium, such as water temperature and salinity.
The basic components of a sound wave 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.
The intensity (or amplitude) of sounds is measured in dB, which is
a relative unit of measurement that is used to express the ratio of one
value of a power or field to another. Decibels are measured on a
logarithmic scale, so a small change in dB corresponds to large changes
in sound pressure. For example, a 10-dB increase is a ten-fold increase
in acoustic power. A 20-dB increase is then a hundred-fold increase in
power and a 30-dB increase is a thousand-fold increase in power.
However, a ten-fold increase in acoustic power does not mean that the
sound is perceived as being 10 times louder. Decibels are a relative
unit comparing two pressures; therefore, a reference pressure must
always be indicated. For underwater sound, this is 1 microPascal
([mu]Pa). For in-air sound, the reference pressure is 20 microPascal
([mu]Pa). The amplitude of a sound can be presented in various ways;
however, NMFS typically considers three metrics. In this proposed IHA,
all decibel levels are referenced to (re) 1[mu]Pa.
Sound exposure level (SEL) represents the total energy in a stated
frequency band over a stated time interval or event and considers both
amplitude and duration of exposure (represented as dB re 1 [mu]Pa\2\ -
s). SEL is a cumulative metric; it can be accumulated over a single
pulse (for pile driving this is often referred to as single-strike SEL;
SELss) or calculated over periods containing multiple pulses
(SELcum). Cumulative SEL represents the total energy
accumulated by a receiver over a defined time window or during an
event. The SEL metric is useful because it allows sound exposures of
different durations to be related to one another in terms of total
acoustic energy. The duration of a sound event and the number of
pulses, however, should be specified as there is no accepted standard
duration over which the summation of energy is measured.
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 (Urick, 1983). 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.
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. Along with
SEL, this metric is used in evaluating the potential for permanent
threshold shift (PTS) and temporary threshold shift (TTS).
Sounds can be either impulsive or non-impulsive. 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 NMFS et
al. (2018) and Southall et al. (2007, 2019a) for an in-depth discussion
of these concepts. Impulsive sound sources (e.g., airguns, explosions,
gunshots, sonic booms, impact pile driving) produce signals that are
brief (typically considered to be less than 1 second), broadband,
atonal transients (American National Standards Institute (ANSI), 1986;
ANSI, 2005; Harris, 1998; National Institute for Occupational Safety
and Health (NIOSH), 1998; International Organization for
Standardization (ISO), 2003) and occur either as isolated events or
repeated in some succession. Impulsive 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. Impulsive sounds are typically
intermittent in nature.
Non-impulsive 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-impulsive sounds can be transient
signals of short duration but without the essential properties of
pulses (e.g., rapid rise time). Examples of non-impulsive sounds
include those produced by vessels, aircraft, machinery operations such
as drilling or dredging, vibratory pile driving, and active sonar
systems. Sounds are also characterized by their temporal component.
Continuous sounds are those whose sound pressure level remains above
that of the ambient sound with negligibly small fluctuations in level
(NIOSH, 1998; ANSI, 2005) while intermittent sounds are defined as
sounds with interrupted levels of low or no sound (NIOSH, 1998). NMFS
identifies Level B harassment thresholds based on if a sound is
continuous or intermittent.
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 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
Hz and 50 kHz (International Council for the Exploration of the Sea
(ICES), 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
[[Page 31020]]
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 dB from day to day (Richardson et al., 1995). The result
is that, depending on the source type and its intensity, sound from a
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals. Human-generated sound is a significant contributor to the
acoustic environment in the project location.
Potential Effects of Underwater Sound on Marine Mammals
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. Broadly, underwater sound from active acoustic sources,
such as those in the Project, 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., 2003; Nowacek et al.,
2007; Southall et al., 2007; G[ouml]tz et al., 2009). 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 et al.,
2007; Zimmer and Tyack, 2007; Tal et al., 2015).
In general, the degree of effect of an acoustic exposure is
intrinsically related to the signal characteristics, received level,
distance from the source, and duration of the sound exposure, in
addition to the contextual factors of the receiver (e.g., behavioral
state at time of exposure, age class, etc.). In general, sudden, high-
level sounds can cause hearing loss as can longer exposures to lower-
level sounds. Moreover, any temporary or permanent loss of hearing will
occur almost exclusively for noise within an animal's hearing range. We
describe below the specific manifestations of acoustic effects that may
occur based on the activities proposed by Vineyard Wind. 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 (at the
greatest distance) 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
(closer to the receiving animal) corresponds with the area where the
signal is audible to the animal and of sufficient intensity to elicit
behavioral or physiological responsiveness. The 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.
Below, we provide additional detail regarding potential impacts on
marine mammals and their habitat from noise in general, starting with
hearing impairment, as well as from the specific activities Vineyard
Wind plans to conduct, to the degree it is available (noting that there
is limited information regarding the impacts of offshore wind
construction on marine mammals).
Hearing Threshold Shift
Marine mammals exposed to high-intensity sound or to lower-
intensity sound for prolonged periods can experience hearing threshold
shift (TS), which NMFS defines as a change, usually an increase, in the
threshold of audibility at a specified frequency or portion of an
individual's hearing range above a previously established reference
level expressed in decibels (NMFS, 2018). Threshold shifts can be
permanent, in which case there is an irreversible increase in the
threshold of audibility at a specified frequency or portion of an
individual's hearing range or temporary, in which there is reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range and the animal's hearing
threshold would fully recover over time (Southall et al., 2019a).
Repeated sound exposure that leads to TTS could cause PTS.
When PTS occurs, there can be physical damage to the sound
receptors in the ear (i.e., tissue damage) whereas TTS represents
primarily tissue fatigue and is reversible (Henderson et al., 2008). 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; Southall et al., 2019a).
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. However,
such relationships are assumed to be similar to those in humans and
other terrestrial mammals. Noise exposure can result in either a
permanent shift in hearing thresholds from baseline (a 40-dB threshold
shift approximates a PTS onset; e.g., Kryter et al., 1966; Miller,
1974; Henderson et al., 2008) or a temporary, recoverable shift in
hearing that returns to baseline (a 6-dB threshold shift approximates a
TTS onset; e.g., Southall et al., 2019a). Based on data from
terrestrial mammals, a precautionary assumption is that the PTS
thresholds, expressed in the unweighted peak sound pressure level
metric (PK), for impulsive sounds (such as impact pile driving pulses)
are at least 6 dB higher than the TTS thresholds and the weighted PTS
cumulative sound exposure level thresholds are 15 (impulsive sound) to
20 (non-impulsive sounds) dB higher than TTS cumulative sound exposure
level thresholds (Southall et al., 2019a). Given the higher level of
sound or longer exposure duration necessary to cause PTS as compared
with TTS, PTS is less likely to occur as a result of these activities;
however, it is possible, and a small amount has been proposed for
authorization for several species.
TTS is the mildest form of hearing impairment that can occur during
[[Page 31021]]
exposure to sound, with a TTS of 6 dB considered the minimum threshold
shift clearly larger than any day-to-day or session-to-session
variation in a subject's normal hearing ability (Schlundt et al., 2000;
Finneran et al., 2000; Finneran et al., 2002). 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.
There is data on sound levels and durations necessary to elicit mild
TTS for marine mammals, but recovery is complicated to predict and
dependent on multiple factors.
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
depending on the degree of interference of marine mammals hearing. 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 (e.g., for successful mother/calf interactions, consistent
detection of prey) 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 (Neophocaena asiaeorientalis))
and six species of pinnipeds (northern elephant seal (Mirounga
angustirostris), harbor seal, ring seal, spotted seal, bearded seal,
and California sea lion (Zalophus californianus)) that were exposed to
a limited number of sound sources (i.e., mostly tones and octave-band
noise with limited number of exposure to impulsive sources such as
seismic airguns or impact pile driving) in laboratory settings
(Southall et al., 2019a). There is currently no data available on
noise-induced hearing loss for mysticetes. For summaries of data on TTS
or PTS in marine mammals or for further discussion of TTS or PTS onset
thresholds, please see Southall et al. (2019a) and NMFS (2018).
Recent studies with captive odontocete species (bottlenose dolphin,
harbor porpoise, beluga, and false killer whale) have observed
increases in hearing threshold levels when individuals received a
warning sound prior to exposure to a relatively loud sound (Nachtigall
and Supin, 2013, 2015; Nachtigall et al., 2016a-c, 2018; Finneran,
2018). These studies suggest that captive animals have a mechanism to
reduce hearing sensitivity prior to impending loud sounds. Hearing
change was observed to be frequency dependent and Finneran (2018)
suggests hearing attenuation occurs within the cochlea or auditory
nerve. Based on these observations on captive odontocetes, the authors
suggest that wild animals may have a mechanism to self-mitigate the
impacts of noise exposure by dampening their hearing during prolonged
exposures of loud sound or if conditioned to anticipate intense sounds
(Finneran, 2018; Nachtigall et al., 2018).
Behavioral Effects
Exposure of marine mammals to sound sources can result in, but is
not limited to, no response or any of the following observable
responses: increased alertness; orientation or attraction to a sound
source; vocal modifications; cessation of feeding; cessation of social
interaction; alteration of movement or diving behavior; habitat
abandonment (temporary or permanent); and in severe cases, panic,
flight, stampede, or stranding, potentially resulting in death
(Southall et al., 2007). A review of marine mammal responses to
anthropogenic sound was first conducted by Richardson (1995). More
recent reviews address studies conducted since 1995 and focused on
observations where the received sound level of the exposed marine
mammal(s) was known or could be estimated (Nowacek et al., 2007;
DeRuiter et al., 2013; Ellison et al., 2012; Gomez et al., 2016). Gomez
et al. (2016) conducted a review of the literature considering the
contextual information of exposure in addition to received level and
found that higher received levels were not always associated with more
severe behavioral responses and vice versa. Southall et al. (2021)
states that results demonstrate that some individuals of different
species display clear yet varied responses, some of which have negative
implications while others appear to tolerate high levels and that
responses may not be fully predictable with simple acoustic exposure
metrics (e.g., received sound level). Rather, the authors state that
differences among species and individuals along with contextual aspects
of exposure (e.g., behavioral state) appear to affect response
probability.
Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception
of and response to (nature and magnitude) an acoustic event. An
animal's prior experience with a sound or sound source affects whether
it is less likely (habituation) or more likely (sensitization) to
respond to certain sounds in the future (animals can also be innately
predisposed to respond to certain sounds in certain ways) (Southall et
al., 2019a). Related to the sound itself, the perceived nearness of the
sound, bearing of the sound (approaching vs. retreating), the
similarity of a sound to biologically relevant sounds in the animal's
environment (i.e., calls of predators, prey, or conspecifics), and
familiarity of the sound may affect the way an animal responds to the
sound (Southall et al., 2007; DeRuiter et al., 2013). Individuals (of
different age, gender, reproductive status, etc.) among most
populations will have variable hearing capabilities, and differing
behavioral sensitivities to sounds that will be affected by prior
conditioning, experience, and current activities of those individuals.
Often, specific acoustic features of the sound and contextual variables
(i.e., proximity, duration, or recurrence of the sound or the current
behavior that the marine mammal is engaged in or its prior experience),
as well as entirely separate factors, such as the physical presence of
a nearby vessel, may be more relevant to the animal's response than the
received level alone.
Overall, the variability of responses to acoustic stimuli depends
on the species receiving the sound, the sound source, and the social,
behavioral, or environmental contexts of exposure (e.g., DeRuiter and
Doukara, 2012). For example, Goldbogen et al. (2013a) demonstrated that
individual behavioral state was critically important in determining
response of blue whales to sonar, noting that some individuals engaged
in deep (greater than 50 m) feeding behavior had greater dive responses
than those in shallow feeding or non-feeding conditions. Some blue
whales in the Goldbogen et al. (2013a) study that were engaged in
shallow feeding behavior demonstrated no clear changes in diving or
movement even when received levels were high (~160 dB re 1[micro]Pa
(microPascal)) for exposures to 3-4 kHz sonar signals, while deep
feeding and non-feeding whales showed a clear response at exposures at
lower
[[Page 31022]]
received levels of sonar and pseudorandom noise. Southall et al. (2011)
found that blue whales had a different response to sonar exposure
depending on behavioral state, more pronounced when deep feeding/travel
modes than when engaged in surface feeding.
With respect to distance influencing disturbance, DeRuiter et al.
(2013) examined behavioral responses of Cuvier's beaked whales to mid-
frequency sonar and found that whales responded strongly at low
received levels (89-127 dB re 1[micro]Pa) by ceasing normal fluking and
echolocation, swimming rapidly away, and extending both dive duration
and subsequent non-foraging intervals when the sound source was 3.4-9.5
km (2.1-5.9 mi) away. Importantly, this study also showed that whales
exposed to a similar range of received levels (78-106 dB re 1[micro]Pa)
from distant sonar exercises (118 km, or 73.3 mi, away) did not elicit
such responses, suggesting that context may moderate reactions. Thus,
distance from the source is an important variable in influencing the
type and degree of behavioral response and this variable is independent
of the effect of received levels (e.g., DeRuiter et al., 2013; Dunlop
et al., 2017a-b, 2018; Falcone et al., 2017; Southall et al., 2019a).
Ellison et al. (2012) outlined an approach to assessing the effects
of sound on marine mammals that incorporates contextual-based factors.
The authors recommend considering not just the received level of sound,
but also the activity the animal is engaged in at the time the sound is
received, the nature and novelty of the sound (i.e., is this a new
sound from the animal's perspective), and the distance between the
sound source and the animal. They submit that this ``exposure
context,'' as described, greatly influences the type of behavioral
response exhibited by the animal. Forney et al. (2017) also point out
that an apparent lack of response (e.g., no displacement or avoidance
of a sound source) may not necessarily mean there is no cost to the
individual or population, as some resources or habitats may be of such
high value that animals may choose to stay, even when experiencing
stress or hearing loss. Forney et al. (2017) recommend considering both
the costs of remaining in an area of noise exposure such as TTS, PTS,
or masking, which could lead to an increased risk of predation or other
threats or a decreased capability to forage, and the costs of
displacement, including potential increased risk of vessel strike,
increased risks of predation or competition for resources, or decreased
habitat suitable for foraging, resting, or socializing. This sort of
contextual information is challenging to predict with accuracy for
ongoing activities that occur over large spatial and temporal expanses.
However, distance is one contextual factor for which data exist to
quantitatively inform a take estimate, and the method for predicting
Level B harassment in this IHA does consider distance to the source.
Other factors are often considered qualitatively in the analysis of the
likely consequences of sound exposure where supporting information is
available.
Behavioral change, such as disturbance manifesting in lost foraging
time, in response to anthropogenic activities is often assumed to
indicate a biologically significant effect on a population of concern.
However, individuals may be able to compensate for some types and
degrees of shifts in behavior, preserving their health and thus their
vital rates and population dynamics. For example, New et al. (2013)
developed a model simulating the complex social, spatial, behavioral,
and motivational interactions of coastal bottlenose dolphins in the
Moray Firth, Scotland, to assess the biological significance of
increased rate of behavioral disruptions caused by vessel traffic.
Despite a modeled scenario in which vessel traffic increased from 70 to
470 vessels a year (a six-fold increase in vessel traffic) in response
to the construction of a proposed offshore renewables facility, the
dolphins' behavioral time budget, spatial distribution, motivations,
and social structure remained unchanged. Similarly, two bottlenose
dolphin populations in Australia were also modeled over 5 years against
a number of disturbances (Reed et al., 2020) and results indicate that
habitat/noise disturbance had little overall impact on population
abundances in either location, even in the most extreme impact
scenarios modeled. Friedlaender et al. (2016) provided the first
integration of direct measures of prey distribution and density
variables incorporated into across-individual analyses of behavior
responses of blue whales to sonar and demonstrated a five-fold increase
in the ability to quantify variability in blue whale diving behavior.
These results illustrate that responses evaluated without such
measurements for foraging animals may be misleading, which again
illustrates the context-dependent nature of the probability of
response.
The following subsections provide examples of behavioral responses
that give an idea of the variability in behavioral responses that would
be expected given the differential sensitivities of marine mammal
species to sound, contextual factors, and the wide range of potential
acoustic sources to which a marine mammal may be exposed. Behavioral
responses that could occur for a given sound exposure should be
determined from the literature that is available for each species, or
extrapolated from closely related species when no information exists,
along with contextual factors.
Avoidance and Displacement
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
(Eschrichtius robustus) and humpback whales are known to change
direction--deflecting from customary migratory paths--in order to avoid
noise from airgun surveys (Malme et al., 1984; Dunlop et al., 2018).
Avoidance is qualitatively different from the flight response but also
differs in the magnitude of the response (i.e., directed movement, rate
of travel, etc.). Avoidance may be short-term with animals returning to
the area once the noise has ceased (e.g., Malme et al., 1984; Bowles et
al., 1994; Goold, 1996; Stone et al., 2000; Morton and Symonds, 2002;
Gailey et al., 2007; D[auml]hne et al., 2013; Russel et al., 2016).
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; Forney et al., 2017). Avoidance of marine mammals during
the construction of offshore wind facilities (specifically, impact pile
driving) has been documented in the literature with some significant
variation in the temporal and spatial degree of avoidance and with most
studies focused on harbor porpoises as one of the most common marine
mammals in European waters (e.g., Tougaard et al., 2009; D[auml]hne et
al., 2013; Thompson et al., 2013; Russell et al., 2016; Brandt et al.,
2018).
Available information on impacts to marine mammals from pile
driving associated with offshore wind is limited to information on
harbor porpoises and seals, as the vast majority of this research has
occurred at European offshore wind projects where large whales and
other odontocete species are uncommon. Harbor porpoises and harbor
seals are considered to be
[[Page 31023]]
behaviorally sensitive species (e.g., Southall et al., 2007) and the
effects of wind farm construction in Europe on these species have been
well documented. These species have received particular attention in
European waters due to their abundance in the North Sea (Hammond et
al., 2002; Nachtsheim et al., 2021). A summary of the literature on
documented effects of wind farm construction on harbor porpoise and
harbor seals is described below.
Brandt et al. (2016) summarized the effects of the construction of
eight offshore wind projects within the German North Sea (i.e., Alpha
Ventus, BARD Offshore I, Borkum West II, DanTysk, Global Tech I,
Meerwind S[uuml]d/Ost, Nordsee Ost, and Riffgat) between 2009 and 2013
on harbor porpoises, combining passive acoustic monitoring (PAM) data
from 2010 to 2013 and aerial surveys from 2009 to 2013 with data on
noise levels associated with pile driving. Results of the analysis
revealed significant declines in porpoise detections during pile
driving when compared to 25-48 hours before pile driving began, with
the magnitude of decline during pile driving clearly decreasing with
increasing distances to the construction site. During the majority of
projects, significant declines in detections (by at least 20 percent)
were found within at least 5-10 km (3.1-6.2 mi) of the pile driving
site, with declines at up to 20-30 km (12.4-18.6 mi) of the pile
driving site documented in some cases. Similar results demonstrating
the long-distance displacement of harbor porpoises (18-25 km; 11.1-15.5
mi) and harbor seals (up to 40 km (24.9 mi)) during impact pile driving
have also been observed during the construction at multiple other
European wind farms (Tougaard et al., 2009; Bailey et al., 2010;
D[auml]hne et al., 2013; Lucke et al., 2012; Haelters et al., 2015).
While harbor porpoises and seals tend to move several kilometers
away from wind farm construction activities, the duration of
displacement has been documented to be relatively temporary. In two
studies at Horns Rev II using impact pile driving, harbor porpoise
returned within 1 to 2 days following cessation of pile driving
(Tougaard et al., 2009; Brandt et al., 2011). Similar recovery periods
have been noted for harbor seals off England during the construction of
four wind farms (Brasseur et al., 2012; Hamre et al., 2011; Hastie et
al., 2015; Russell et al., 2016). In some cases, an increase in harbor
porpoise activity has been documented inside wind farm areas following
construction (e.g., Lindeboom et al., 2011). Other studies have noted
longer term impacts after impact pile driving. Near Dogger Bank in
Germany, harbor porpoises continued to avoid the area for over 2 years
after construction began (Gilles et al., 2009). Approximately 10 years
after construction of the Nysted wind farm, harbor porpoise abundance
had not recovered to the original levels previously seen, although the
echolocation activity was noted to have been increasing when compared
to the previous monitoring period (Teilmann and Carstensen, 2012).
However, overall, there are no indications for a population decline of
harbor porpoises in European waters (e.g., Brandt et al., 2016).
Notably, where significant differences in displacement and return rates
have been identified for these species, the occurrence of secondary
project-specific influences such as use of mitigation measures (e.g.,
bubble curtains, acoustic deterrent devices), or the manner in which
species use the habitat in the LIA, are likely the driving factors of
this variation.
NMFS notes that the aforementioned European studies involved
installing much smaller monopiles than Vineyard Wind proposes to
install (Brandt et al., 2016) and, therefore we anticipate noise levels
from impact pile driving to be louder. However, we do not anticipate
any greater severity of response due to harbor porpoise and harbor seal
habitat use off Massachusetts or population-level consequences similar
to European findings. In many cases, harbor porpoises and harbor seals
are resident to the areas where European wind farms have been
constructed. However, off Massachusetts, harbor porpoises and seals are
more transient, and a very small percentage of the harbor seal
population are only seasonally present with no rookeries established
(Hayes et al., 2022). In summary, we anticipate that harbor porpoise
and harbor seals will likely respond to pile driving by moving several
kilometers away from the source but return to typical habitat use
patterns when pile driving ceases.
Some avoidance behavior of other marine mammal species has been
documented to be dependent on distance from the source. As described
above, DeRuiter et al. (2013) noted that distance from a sound source
may moderate marine mammal reactions in their study of Cuvier's beaked
whales (an acoustically sensitive species), which showed the whales
swimming rapidly and silently away when a sonar signal was 3.4-9.5 km
(2.1-5.9 mi) away while showing no such reaction to the same signal
when the signal was 118 km (73.3 mi) away even though the received
levels were similar. Tyack et al. (1983) conducted playback studies of
Surveillance Towed Array Sensor System (SURTASS) low-frequency active
(LFA) sonar in a gray whale migratory corridor off California. Similar
to NARWs, gray whales migrate close to shore (approximately +2 km (+1.2
mi)) and are low-frequency hearing specialists. The LFA sonar source
was placed within the gray whale migratory corridor (approximately 2 km
(1.2 mi) offshore) and offshore of most, but not all, migrating whales
(approximately 4 km (2.5 mi) offshore). These locations influenced
received levels and distance to the source. For the inshore playbacks,
not unexpectedly, the louder the source level of the playback (i.e.,
the louder the received level), whale avoided the source at greater
distances. Specifically, when the source levels were 170 and 178 dB
rms, whales avoided the inshore source at ranges of several hundred
meters, similar to avoidance responses reported by Malme et al. (1983,
1984). Whales exposed to source levels of 185 dB rms demonstrated
avoidance levels at ranges of +1 km (+0.6 mi). Responses to the
offshore source broadcasting at source levels of 185 and 200 dB,
avoidance responses were greatly reduced. While there was observed
deflection from course, in no case did a whale abandon its migratory
behavior.
The signal context of the noise exposure has been shown to play an
important role in avoidance responses. In a 2007-2008 Bahamas study,
playback sounds of a potential predator--a killer whale--resulted in a
similar but more pronounced reaction in beaked whales (an acoustically
sensitive species), which included longer inter-dive intervals and a
sustained straight-line departure of more than 20 km (12.4 mi) from the
area (Boyd et al., 2008; Southall et al., 2009; Tyack et al., 2011). In
contrast, the sounds produced by pile driving activities do not have
signal characteristics similar to predators. Therefore, we would not
expect such extreme reactions to occur. Southall et al. (2011) found
that blue whales had a different response to sonar exposure depending
on behavioral state, more pronounced when deep feeding/travel modes
than when engaged in surface feeding.
One potential consequence of behavioral avoidance is the altered
energetic expenditure of marine mammals because energy is required to
move and avoid surface vessels or the sound field associated with
active sonar (Frid and Dill, 2002). Most animals can avoid that
energetic cost by swimming away at slow speeds or speeds that
[[Page 31024]]
minimize the cost of transport (Miksis-Olds, 2006), as has been
demonstrated in Florida manatees (Miksis-Olds, 2006). Those energetic
costs increase, however, when animals shift from a resting state, which
is designed to conserve an animal's energy, to an active state that
consumes energy the animal would have conserved had it not been
disturbed. Marine mammals that have been disturbed by anthropogenic
noise and vessel approaches are commonly reported to shift from resting
to active behavioral states, which would imply that they incur an
energy cost.
Forney et al. (2017) detailed the potential effects of noise on
marine mammal populations with high site fidelity, including
displacement and auditory masking, noting that a lack of observed
response does not imply absence of fitness costs and that apparent
tolerance of disturbance may have population-level impacts that are
less obvious and difficult to document. Avoidance of overlap between
disturbing noise and areas and/or times of particular importance for
sensitive species may be critical to avoiding population-level impacts
because (particularly for animals with high site fidelity) there may be
a strong motivation to remain in the area despite negative impacts.
Forney et al. (2017) stated that, for these animals, remaining in a
disturbed area may reflect a lack of alternatives rather than a lack of
effects.
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, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, but observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996; Frid and Dill, 2002). 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, beaked
whale strandings (Cox et al., 2006; D'Amico et al., 2009). 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.
Flight responses of marine mammals have been documented in response to
mobile high intensity active sonar (e.g., Tyack et al., 2011; DeRuiter
et al., 2013; Wensveen et al., 2019), and more severe responses have
been documented when sources are moving towards an animal or when they
are surprised by unpredictable exposures (Watkins, 1986; Falcone et
al., 2017). Generally speaking, however, marine mammals would be
expected to be less likely to respond with a flight response to
stationery pile driving (which they can sense is stationery and
predictable), unless they are within the area ensonified above
behavioral harassment thresholds at the moment the pile driving begins
(Watkins, 1986; Falcone et al., 2017).
Diving and Foraging
Changes in dive behavior in response to noise exposure can vary
widely. They 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;
Goldbogen et al., 2013b). Variations in dive behavior may reflect
interruptions in biologically significant activities (e.g., foraging)
or they may be of little biological significance. Variations in dive
behavior may also expose an animal to potentially harmful conditions
(e.g., increasing the chance of ship-strike) or may serve as an
avoidance response that enhances survivorship. The impact of a
variation in diving resulting from an acoustic exposure depends on what
the animal is doing at the time of the exposure, the type and magnitude
of the response, and the context within which the response occurs
(e.g., the surrounding environmental and anthropogenic circumstances).
Nowacek et al. (2004) reported disruptions of dive behaviors in
foraging NARWs when exposed to an alerting stimulus, an action, they
noted, that could lead to an increased likelihood of ship strike. The
alerting stimulus was in the form of an 18-minute exposure that
included three 2-minute signals played three times sequentially. This
stimulus was designed with the purpose of providing signals distinct to
background noise that serve as localization cues. However, the whales
did not respond to playbacks of either right whale social sounds or
vessel noise, highlighting the importance of the sound characteristics
in producing a behavioral reaction. Although source levels for the
proposed pile driving activities may exceed the received level of the
alerting stimulus described by Nowacek et al. (2004), proposed
mitigation strategies (further described in the Proposed Mitigation
section) will reduce the severity of response to proposed pile driving
activities. Converse to the behavior of NARWs, Indo-Pacific humpback
dolphins have been observed to dive for longer periods of time in areas
where vessels were present and/or approaching (Ng and Leung, 2003). In
both of these studies, the influence of the sound exposure cannot be
decoupled from the physical presence of a surface vessel, thus
complicating interpretations of the relative contribution of each
stimulus to the response. Indeed, the presence of surface vessels,
their approach, and speed of approach, seemed to be significant factors
in the response of the Indo-Pacific humpback dolphins (Ng and Leung,
2003). Low-frequency signals of the Acoustic Thermometry of Ocean
Climate (ATOC) sound source were not found to affect dive times of
humpback whales in Hawaiian waters (Frankel and Clark, 2000) or to
overtly affect elephant seal dives (Costa et al., 2003). They did,
however, produce subtle effects that varied in direction and degree
among the individual seals, illustrating the equivocal nature of
behavioral effects and consequent difficulty in defining and predicting
them.
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 cessation of secondary
indicators of foraging (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; Southall et al., 2019b). An understanding 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 can facilitate the assessment of whether
foraging disruptions are likely to incur fitness consequences
(Goldbogen et al., 2013b; Farmer et al., 2018; Pirotta et al., 2018a;
Southall et al., 2019a; Pirotta et al., 2021).
Impacts on marine mammal foraging rates from noise exposure have
been documented, though there is little data regarding the impacts of
offshore turbine construction specifically. Several broader examples
follow, and it is reasonable to expect that exposure to noise produced
during the year that the proposed IHA would be effective could have
similar impacts. Visual tracking, passive acoustic monitoring, and
movement recording tags were used to
[[Page 31025]]
quantify sperm whale behavior prior to, during, and following exposure
to airgun arrays at received levels in the range 140-160 dB at
distances of 7-13 km (4.3-8.1 mi), following a phase-in of sound
intensity and full array exposures at 1-13 km (0.6-8.1 mi) (Madsen et
al., 2006; Miller et al., 2009). Sperm whales did not exhibit
horizontal avoidance behavior at the surface. However, foraging
behavior may have been affected. The sperm whales exhibited 19 percent
less vocal (buzz) rate during full exposure relative to post exposure,
and the whale that was approached most closely had an extended resting
period and did not resume foraging until the airguns had ceased firing.
The remaining whales continued to execute foraging dives throughout
exposure; however, swimming movements during foraging dives were 6
percent lower during exposure than during control periods (Miller et
al., 2009). Miller et al. (2009) noted that more data are required to
understand whether the differences were due to exposure or natural
variation in sperm whale behavior. Balaenopterid whales exposed to
moderate low-frequency signals similar to the ATOC sound source
demonstrated no variation in foraging activity (Croll et al., 2001),
whereas five out of six NARWs exposed to an acoustic alarm interrupted
their foraging dives (Nowacek et al., 2004). Although the received SPLs
were similar in the latter two studies, the frequency, duration, and
temporal pattern of signal presentation were different. These factors,
as well as differences in species sensitivity, are likely contributing
factors to the differential response. The noise generated by Vineyard
Wind's proposed activities would at least partially overlap in
frequency with signals described by Nowacek et al. (2004) and Croll et
al. (2001). Blue whales exposed to mid-frequency sonar in the Southern
California Bight were less likely to produce low-frequency calls
usually associated with feeding behavior (Melc[oacute]n et al., 2012).
However, Melc[oacute]n et al. (2012) were unable to determine if
suppression of low-frequency calls reflected a change in their feeding
performance or abandonment of foraging behavior and indicated that
implications of the documented responses are unknown. Further, it is
not known whether the lower rates of calling actually indicated a
reduction in feeding behavior or social contact since the study used
data from remotely deployed, passive acoustic monitoring buoys. Results
from the 2010-2011 field season of a behavioral response study of
tagged blue whales in Southern California waters indicated that, in
some cases and at low received levels, the whales responded to mid-
frequency sonar but that those responses were mild and there was a
quick return to their baseline activity (Southall et al., 2011, 2012b,
2019).
Information on or estimates of the energetic requirements of the
individuals and the relationship between prey availability, foraging
effort and success, and the life history stage of the animal will help
better inform a determination of whether foraging disruptions incur
fitness consequences. Foraging strategies may impact foraging
efficiency, such as by reducing foraging effort and increasing success
in prey detection and capture, in turn promoting fitness and allowing
individuals to better compensate for foraging disruptions. Surface
feeding blue whales did not show a change in behavior in response to
mid-frequency simulated and real sonar sources with received levels
between 90 and 179 dB re 1 [micro]Pa, but deep feeding and non-feeding
whales showed temporary reactions including cessation of feeding,
reduced initiation of deep foraging dives, generalized avoidance
responses, and changes to dive behavior (DeRuiter et al., 2017;
Goldbogen et al., 2013b; Sivle et al., 2015). Goldbogen et al. (2013b)
indicate that disruption of feeding and displacement could impact
individual fitness and health. However, for this to be true, we would
have to assume that an individual whale could not compensate for this
lost feeding opportunity by either immediately feeding at another
location, by feeding shortly after cessation of acoustic exposure, or
by feeding at a later time. There is no indication that individual
fitness and health would be impacted by an activity that influences
foraging disruption, particularly since unconsumed prey would likely
still be available in the environment in most cases following the
cessation of acoustic exposure.
Similarly, while the rates of foraging lunges decrease in humpback
whales due to sonar exposure, there was variability in the response
across individuals, with one animal ceasing to forage completely and
another animal starting to forage during the exposure (Sivle et al.,
2016). In addition, almost half of the animals that demonstrated
avoidance were foraging before the exposure, but the others were not;
the animals that avoided while not feeding responded at a slightly
lower received level and greater distance than those that were feeding
(Wensveen et al., 2017). These findings indicate the behavioral state
of the animal and foraging strategies play a role in the type and
severity of a behavioral response. For example, when the prey field was
mapped and used as a covariate in examining how behavioral state of
blue whales is influenced by mid-frequency sound, the response in blue
whale deep-feeding behavior was even more apparent, reinforcing the
need for contextual variables to be included when assessing behavioral
responses (Friedlaender et al., 2016).
Vocalizations and Auditory Masking
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, production of echolocation clicks, calling,
and singing. Changes in vocalization behavior in response to
anthropogenic noise can occur for any of these modes and may result
directly from increased vigilance or a startle response, or from a need
to compete with an increase in background noise (see Erbe et al., 2016
review on communication masking), the latter of which is described more
below.
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) and blue whales increased song production (Di Iorio
and Clark, 2009), while NARWs 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 or reduce sound production during production
of aversive signals (Bowles et al., 1994; Thode et al., 2020; Cerchio
et al., 2014; McDonald et al., 1995). Blackwell et al. (2015) showed
that whales increased calling rates as soon as airgun signals were
detectable before ultimately decreasing calling rates at higher
received levels.
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, or
navigation) (Richardson et al., 1995; Erbe and Farmer, 2000; Tyack,
2000; Erbe et al., 2016; Sorensen et al., 2023). 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
[[Page 31026]]
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.
Masking these acoustic signals can disturb the behavior of
individual animals, groups of animals, or entire populations. Masking
can lead to behavioral changes including vocal changes (e.g., Lombard
effect, increasing amplitude, or changing frequency), cessation of
foraging or lost foraging opportunities, and leaving an area, to both
signalers and receivers, in an attempt to compensate for noise levels
(Erbe et al., 2016) or because sounds that would typically have
triggered a behavior were not detected. Even when animals attempt to
compensate for masking, such as by increasing the amplitude or duration
of their signals, this may still be insufficient to maintain behavioral
coordination between individuals necessary for complex behaviors,
foraging, and navigation (Sorensen et al., 2023). In humans,
significant masking of tonal signals occurs as a result of exposure to
noise in a narrow band of similar frequencies. As the sound level
increases, the detection of frequencies above those of the masking
stimulus decreases. This principle is expected to apply to marine
mammals as well because of common biomechanical cochlear properties
across taxa.
Therefore, when the coincident (masking) sound is man-made, it may
be considered harassment when disrupting behavioral patterns. It is
important to distinguish TTS and PTS, which persist after the sound
exposure, from masking, which only occurs during the sound exposure.
Because masking (without resulting in threshold shift) 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; Matthews, 2017) 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; Cholewiak et al., 2018).
The echolocation calls of toothed whales are subject to masking by
high-frequency sound. Human data indicate low-frequency sound can mask
high-frequency sounds (i.e., upward masking). Studies on captive
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species
may use various processes to reduce masking effects (e.g., adjustments
in echolocation call intensity or frequency as a function of background
noise conditions). There is also evidence that the directional hearing
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A
study by Nachtigall and Supin (2008) showed that false killer whales
adjust their hearing to compensate for ambient sounds and the intensity
of returning echolocation signals.
Impacts on signal detection, measured by masked detection
thresholds, are not the only important factors to address when
considering the potential effects of masking. As marine mammals use
sound to recognize conspecifics, prey, predators, or other biologically
significant sources (Branstetter et al., 2016), it is also important to
understand the impacts of masked recognition thresholds (often called
``informational masking''). Branstetter et al. (2016) measured masked
recognition thresholds for whistle-like sounds of bottlenose dolphins
and observed that they are approximately 4 dB above detection
thresholds (energetic masking) for the same signals. Reduced ability to
recognize a conspecific call or the acoustic signature of a predator
could have severe negative impacts. Branstetter et al. (2016) observed
that if ``quality communication'' is set at 90 percent recognition the
output of communication space models (which are based on 50 percent
detection) would likely result in a significant decrease in
communication range.
As marine mammals use sound to recognize predators (Allen et al.,
2014; Cummings and Thompson, 1971; Cur[eacute] et al., 2015; Fish and
Vania, 1971), the presence of masking noise may also prevent marine
mammals from responding to acoustic cues produced by their predators,
particularly if it occurs in the same frequency band. For example,
harbor seals that reside in the coastal waters off British Columbia are
frequently targeted by mammal-eating killer whales. The seals
acoustically discriminate between the calls of mammal-eating and fish-
eating killer whales (Deecke et al., 2002), a capability that should
increase survivorship while reducing the energy required to attend to
all killer whale calls. Similarly, sperm whales (Cur[eacute] et al.,
2016; Isojunno et al., 2016), long-finned pilot whales (Visser et al.,
2016), and humpback whales (Cur[eacute] et al., 2015) changed their
behavior in response to killer whale vocalization playbacks; these
findings indicate that some recognition of predator cues could be
missed if the killer whale vocalizations were masked. The potential
effects of masked predator acoustic cues depend on the duration of the
masking noise and the likelihood of a marine mammal encountering a
predator during the time that detection and recognition of predator
cues are impeded.
Redundancy and context can also facilitate detection of weak
signals. These phenomena may help marine mammals detect weak sounds in
the presence of natural or manmade noise. Most masking studies in
marine mammals present the test signal and the masking noise from the
same direction. The dominant background noise may be highly directional
if it comes from a particular anthropogenic source such as a ship or
industrial site. Directional hearing may significantly reduce the
masking effects of these sounds by improving the effective signal-to-
noise ratio.
Masking affects both senders and receivers of acoustic signals and,
at higher levels and longer duration, 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
[[Page 31027]]
in terms of sound pressure level (SPL)) in the world's ocean from pre-
industrial periods, with most of the increase from distant commercial
shipping (Hildebrand, 2009; Cholewiak et al., 2018). All anthropogenic
sound sources, but especially chronic and lower-frequency signals
(e.g., from commercial vessel traffic), contribute to elevated ambient
sound levels, thus intensifying masking.
In addition to making it more difficult for animals to perceive and
recognize acoustic cues in their environment, anthropogenic sound
presents separate challenges for animals that are vocalizing. When they
vocalize, animals are aware of environmental conditions that affect the
``active space'' (or communication space) of their vocalizations, which
is the maximum area within which their vocalizations can be detected
before it drops to the level of ambient noise (Brenowitz, 2004; Brumm
et al., 2004; Lohr et al., 2003). Animals are also aware of
environmental conditions that affect whether listeners can discriminate
and recognize their vocalizations from other sounds, which is more
important than simply detecting that a vocalization is occurring
(Brenowitz, 1982; Brumm et al., 2004; Dooling, 2004; Marten and Marler,
1977; Patricelli and Blickley, 2006). Most species that vocalize have
evolved with an ability to adjust their vocalizations to increase the
signal-to-noise ratio, active space, and recognizability/
distinguishability of their vocalizations in the face of temporary
changes in background noise (Brumm et al., 2004; Patricelli and
Blickley, 2006). Vocalizing animals can adjust their vocalization
characteristics such as the frequency structure, amplitude, temporal
structure, and temporal delivery (repetition rate), or ceasing to
vocalize.
Many animals will combine several of these strategies to compensate
for high levels of background noise. Anthropogenic sounds that reduce
the signal-to-noise ratio of animal vocalizations; increase the masked
auditory thresholds of animals listening for such vocalizations; or
reduce the active space of an animal's vocalizations impair
communication between animals. Most animals that vocalize have evolved
strategies to compensate for the effects of short-term or temporary
increases in background or ambient noise on their songs or calls.
Although the fitness consequences of these vocal adjustments are not
directly known in all instances, like most other trade-offs animals
must make, some of these strategies likely come at a cost (Patricelli
and Blickley, 2006; Noren et al., 2017; Noren et al., 2020). Shifting
songs and calls to higher frequencies may also impose energetic costs
(Lambrechts, 1996).
Marine mammals are also known to make vocal changes in response to
anthropogenic noise. In cetaceans, vocalization changes have been
reported from exposure to anthropogenic noise sources such as sonar,
vessel noise, and seismic surveying (e.g., Gordon et al., 2003; Di
Iorio and Clark, 2009; Hatch et al., 2012; Holt et al., 2009, 2011;
Lesage et al., 1999; McDonald et al., 2009; Parks et al., 2007; Risch
et al., 2012; Rolland et al., 2012), as well as changes in the natural
acoustic environment (Dunlop et al., 2014). Vocal changes can be
temporary or can be persistent. For example, model simulation suggests
that the increase in starting frequency for the NARW upcall over the
last 50 years resulted in increased detection ranges between right
whales. The frequency shift, coupled with an increase in call intensity
by 20 dB, led to a call detectability range of less than 3 km (1.9 mi)
to over 9 km (5.6 mi) (Tennessen and Parks, 2016). Holt et al. (2009)
measured killer whale call source levels and background noise levels in
the 1 to 40 kHz band and reported that the whales increased their call
source levels by 1-dB SPL for every 1-dB SPL increase in background
noise level. Similarly, another study on St. Lawrence River belugas
reported a similar rate of increase in vocalization activity in
response to passing vessels (Scheifele et al., 2005). Di Iorio and
Clark (2009) showed that blue whale calling rates vary in association
with seismic sparker survey activity, with whales calling more on days
with surveys than on days without surveys. They suggested that the
whales called more during seismic survey periods as a way to compensate
for the elevated noise conditions.
In some cases, these vocal changes may have fitness consequences,
such as an increase in metabolic rates and oxygen consumption, as
observed in bottlenose dolphins when increasing their call amplitude
(Holt et al., 2015). A switch from vocal communication to physical,
surface-generated sounds such as pectoral fin slapping or breaching was
observed for humpback whales in the presence of increasing natural
background noise levels, indicating that adaptations to masking may
also move beyond vocal modifications (Dunlop et al., 2010).
While these changes all represent possible tactics by the sound-
producing animal to reduce the impact of masking, the receiving animal
can also reduce masking by using active listening strategies such as
orienting to the sound source, moving to a quieter location, or
reducing self-noise from hydrodynamic flow by remaining still. The
temporal structure of noise (e.g., amplitude modulation) may also
provide a considerable release from masking through comodulation
masking release (a reduction of masking that occurs when broadband
noise, with a frequency spectrum wider than an animal's auditory filter
bandwidth at the frequency of interest, is amplitude modulated)
(Branstetter and Finneran, 2008; Branstetter et al., 2013). Signal type
(e.g., whistles, burst-pulse, sonar clicks) and spectral
characteristics (e.g., frequency modulated with harmonics) may further
influence masked detection thresholds (Branstetter et al., 2016;
Cunningham et al., 2014).
Masking is more likely to occur in the presence of broadband,
relatively continuous noise sources, such as vessels. Several studies
have shown decreases in marine mammal communication space and changes
in behavior as a result of the presence of vessel noise. For example,
right whales were 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) as well as increasing the
amplitude (intensity) of their calls (Parks, 2009, 2011). Clark et al.
(2009) observed that right whales' communication space decreased by up
to 84 percent in the presence of vessels due to an increase in ambient
noise from vessels in proximity to the whales. Cholewiak et al. (2018)
also observed loss in communication space in Stellwagen National Marine
Sanctuary for NARWs, fin whales, and humpback whales with increased
ambient noise and shipping noise. Although humpback whales off
Australia did not change the frequency or duration of their
vocalizations in the presence of ship noise, their source levels were
lower than expected based on source level changes to wind noise,
potentially indicating some signal masking (Dunlop, 2016). Multiple
delphinid species have also been shown to increase the minimum or
maximum frequencies of their whistles in the presence of anthropogenic
noise and reduced communication space (e.g., Holt et al., 2009, 2011;
Gervaise et al., 2012; Williams et al., 2013; Hermannsen et al., 2014;
Papale et al., 2015; Liu et al., 2017). While masking impacts are not a
concern from lower intensity, higher frequency HRG surveys, some degree
of masking would be expected in the vicinity of turbine pile driving
and concentrated support vessel operation.
[[Page 31028]]
However, pile driving is an intermittent sound and would not be
continuous throughout the day.
Habituation and Sensitization
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). Habituation is considered 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 having a neutral or
positive outcome (Bejder et al., 2009). Animals are most likely to
habituate to sounds that are predictable and unvarying. 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.
Both habituation and sensitization require an ongoing learning
process. 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; National Research Council (NRC), 2003; Wartzok et al., 2003;
Southall et al., 2019b). Controlled experiments with captive marine
mammals have shown pronounced behavioral reactions, including avoidance
of loud sound sources (e.g., Ridgway et al., 1997; Finneran et al.,
2003; Houser et al., 2013a-b; Kastelein et al., 2018). Observed
responses of wild marine mammals to loud impulsive 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; Richardson et al.,
1995; Nowacek et al., 2007; Tougaard et al., 2009; Brandt et al., 2011,
2012, 2014, 2018; D[auml]hne et al., 2013; Russell et al., 2016).
Stone (2015) reported data from at-sea observations during 1,196
airgun surveys from 1994 to 2010. When large arrays of airguns
(considered to be 500 cubic inches (in\3\) or more) were firing,
lateral displacement, more localized avoidance, or other changes in
behavior were evident for most odontocetes. However, significant
responses to large arrays were found only for the minke whale and fin
whale. Behavioral responses observed included changes in swimming or
surfacing behavior with indications that cetaceans remained near the
water surface at these times. Behavioral observations of gray whales
during an airgun survey monitored whale movements and respirations
before, during, and after seismic surveys (Gailey et al., 2016).
Behavioral state and water depth were the best ``natural'' predictors
of whale movements and respiration, and after accounting for natural
variation, none of the response variables were significantly associated
with survey or vessel sounds. 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.
Physiological 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., Selye, 1950; Moberg and Mench,
2000). In many cases, an animal's first, and sometimes most economical
response (in terms of energetic costs) 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 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
sufficiently 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 specifically in wild
populations (e.g., Lusseau and Bejder, 2007; Romano et al., 2002a;
Rolland et al., 2012). 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 NARWs.
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, 2017). Respiration naturally varies with different behaviors, and
variations in respiration 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. Mean exhalation rates of gray whales at rest and while
diving were found to be unaffected by seismic surveys conducted
adjacent to the whale feeding grounds (Gailey et al., 2007). Studies
with captive harbor porpoises show increased respiration rates upon
introduction of acoustic alarms (Kastelein et al., 2001, 2006a) and
emissions for underwater data transmission (Kastelein et al., 2005).
However, exposure of the same acoustic alarm to a striped dolphin under
the same conditions did not elicit a response (Kastelein et al.,
2006a), 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.
Stranding
The definition for a stranding under the MMPA is that: (A) a marine
mammal is dead and is (i) on a beach or shore
[[Page 31029]]
of the United States, or (ii) in waters under the jurisdiction of the
United States (including any navigable waters); or (B) a marine mammal
is alive and is (i) on a beach or shore of the United States and is
unable to return to the water, (ii) on a beach or shore of the United
States and, although able to return to the water, is in need of
apparent medical attention, or (iii) in the waters under the
jurisdiction of the United States (including any navigable waters), but
is unable to return to its natural habitat under its own power or
without assistance (16 U.S.C. 1421h).
Marine mammal strandings have been linked to a variety of causes,
such as illness from exposure to infectious agents, biotoxins, or
parasites; starvation; unusual oceanographic or weather events; or
anthropogenic causes including fishery interaction, ship strike,
entrainment, entrapment, sound exposure, or combinations of these
stressors sustained concurrently or in series. There have been multiple
events worldwide in which marine mammals (primarily beaked whales, or
other deep divers) have stranded coincident with relatively nearby
activities utilizing loud sound sources (primarily military training
events), and five in which mid-frequency active sonar has been more
definitively determined to have been a contributing factor.
There are multiple theories regarding the specific mechanisms
responsible for marine mammal strandings caused by exposure to loud
sounds. One primary theme is the behaviorally mediated responses of
deep-diving species (odontocetes), in which their startled response to
an acoustic disturbance: (1) affects ascent or descent rates, the time
they stay at depth or the surface, or other regular dive patterns that
are used to physiologically manage gas formation and absorption within
their bodies, such that the formation or growth of gas bubbles damages
tissues or causes other injury; or (2) results in their flight to
shallow areas, enclosed bays, or other areas considered ``out of
habitat,'' in which they become disoriented and physiologically
compromised. For more information on marine mammal stranding events and
potential causes, please see the Stranding and Mortality discussion in
NMFS' proposed rule for the Navy's Training and Testing Activities in
the Hawaii-Southern California Training and Testing Study Area (83 FR
29872, 29928; June 26, 2018).
The construction activities proposed by Vineyard Wind (i.e., pile
driving) are not expected to result in marine mammal strandings. Of the
strandings documented to date worldwide, NMFS is not aware of any being
attributed to pile driving. While vessel strikes could kill or injure a
marine mammal (which may then eventually strand), the required
mitigation measures would reduce the potential for take from these
activities to de minimis levels (see Proposed Mitigation section for
more details). As described above, no mortality or serious injury is
anticipated or proposed to be authorized from any Project activities.
Potential Effects of Disturbance on Marine Mammal Fitness
The different ways that marine mammals respond to sound are
sometimes indicators of the ultimate effect that exposure to a given
stimulus will have on the well-being (survival, reproduction, etc.) of
an animal. There are numerous data relating the exposure of terrestrial
mammals from sound to effects on reproduction or survival, and data for
marine mammals continues to grow. Several authors have reported that
disturbance stimuli may cause animals to abandon nesting and foraging
sites (Sutherland and Crockford, 1993); may cause animals to increase
their activity levels and suffer premature deaths or reduced
reproductive success when their energy expenditures exceed their energy
budgets (Daan et al., 1996; Feare, 1976; Mullner et al., 2004); or may
cause animals to experience higher predation rates when they adopt
risk-prone foraging or migratory strategies (Frid and Dill, 2002). Each
of these studies addressed the consequences of animals shifting from
one behavioral state (e.g., resting or foraging) to another behavioral
state (e.g., avoidance or escape behavior) because of human disturbance
or disturbance stimuli.
Attention is the cognitive process of selectively concentrating on
one aspect of an animal's environment while ignoring other things
(Posner, 1994). Because animals (including humans) have limited
cognitive resources, there is a limit to how much sensory information
they can process at any time. The phenomenon called ``attentional
capture'' occurs when a stimulus (usually a stimulus that an animal is
not concentrating on or attending to) ``captures'' an animal's
attention. This shift in attention can occur consciously or
subconsciously (for example, when an animal hears sounds that it
associates with the approach of a predator) and the shift in attention
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has
captured an animal's attention, the animal can respond by ignoring the
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus
as a disturbance and respond accordingly, which includes scanning for
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
Vigilance is an adaptive behavior that helps animals determine the
presence or absence of predators, assess their distance from
conspecifics, or to attend cues from prey (Bednekoff and Lima, 1998;
Treves, 2000). Despite those benefits, however, vigilance has a cost of
time; when animals focus their attention on specific environmental
cues, they are not attending to other activities 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 (Saino,
1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002; Purser and
Radford, 2011). Animals will spend more time being vigilant, which may
translate to less time foraging or resting, when disturbance stimuli
approach them more directly, remain at closer distances, have a greater
group size (e.g., multiple surface vessels), or when they co-occur with
times that an animal perceives increased risk (e.g., when they are
giving birth or accompanied by a calf).
The primary mechanism by which increased vigilance and disturbance
appear to affect the fitness of individual animals is by disrupting an
animal's time budget and, as a result, reducing the time they might
spend foraging and resting (which increases an animal's activity rate
and energy demand while decreasing their caloric intake/energy). In a
study of northern resident killer whales off Vancouver Island, exposure
to boat traffic was shown to reduce foraging opportunities and increase
traveling time (Holt et al., 2021). A simple bioenergetics model was
applied to show that the reduced foraging opportunities equated to a
decreased energy intake of 18 percent while the increased traveling
incurred an increased energy output of 3-4 percent, which suggests that
a management action based on avoiding interference with foraging might
be particularly effective.
On a related note, many animals perform vital functions, such as
feeding, resting, traveling, and socializing, on a diel cycle (24-hour
cycle). Behavioral reactions to noise exposure (such as disruption of
critical life functions, displacement, or avoidance of important
habitat) are more likely to be significant for fitness if they last
more than one diel cycle or recur on subsequent days (Southall et al.,
2007). Consequently, a behavioral response lasting less than 1
[[Page 31030]]
day and not recurring on subsequent days is not considered particularly
severe unless it could directly affect reproduction or survival
(Southall et al., 2007). It is important to note the difference between
behavioral reactions lasting or recurring over multiple days and
anthropogenic activities lasting or recurring over multiple days. For
example, just because certain activities last for multiple days does
not necessarily mean that individual animals will be either exposed to
those activity-related stressors (i.e., sonar) for multiple days or
further exposed in a manner that would result in sustained multi-day
substantive behavioral responses. However, special attention is
warranted where longer-duration activities overlay areas in which
animals are known to congregate for longer durations for biologically
important behaviors.
There are few studies that directly illustrate the impacts of
disturbance on marine mammal populations. Lusseau and Bejder (2007)
present data from three long-term studies illustrating the connections
between disturbance from whale-watching boats and population-level
effects in cetaceans. In Shark Bay, Australia, the abundance of
bottlenose dolphins was compared within adjacent control and tourism
sites over three consecutive 4.5-year periods of increasing tourism
levels. Between the second and third time periods, in which tourism
doubled, dolphin abundance decreased by 15 percent in the tourism area
and did not change significantly in the control area. In Fiordland, New
Zealand, two populations (Milford and Doubtful Sounds) of bottlenose
dolphins with tourism levels that differed by a factor of seven were
observed and significant increases in traveling time and decreases in
resting time were documented for both. Consistent short-term avoidance
strategies were observed in response to tour boats until a threshold of
disturbance was reached (average of 68 minutes between interactions),
after which the response switched to a longer-term habitat displacement
strategy. For one population, tourism only occurred in a part of the
home range. However, tourism occurred throughout the home range of the
Doubtful Sound population and once boat traffic increased beyond the
68-minute threshold (resulting in abandonment of their home range/
preferred habitat), reproductive success drastically decreased
(increased stillbirths) and abundance decreased significantly (from 67
to 56 individuals in a short period).
In order to understand how the effects of activities may or may not
impact species and stocks of marine mammals, it is necessary to
understand not only what the likely disturbances are going to be but
how those disturbances may affect the reproductive success and
survivorship of individuals, and then how those impacts to individuals
translate to population-level effects. Following on the earlier work of
a committee of the U.S. NRC (NRC, 2005), New et al. (2014), in an
effort termed the Potential Consequences of Disturbance (PCoD),
outlined an updated conceptual model of the relationships linking
disturbance to changes in behavior and physiology, health, vital rates,
and population dynamics. This framework is a four-step process
progressing from changes in individual behavior and/or physiology, to
changes in individual health, then vital rates, and finally to
population-level effects. In this framework, behavioral and
physiological changes can have direct (acute) effects on vital rates,
such as when changes in habitat use or increased stress levels raise
the probability of mother-calf separation or predation; indirect and
long-term (chronic) effects on vital rates, such as when changes in
time/energy budgets or increased disease susceptibility affect health,
which then affects vital rates; or no effect to vital rates (New et
al., 2014).
Since the PCoD general framework was outlined and the relevant
supporting literature compiled, multiple studies developing state-space
energetic models for species with extensive long-term monitoring (e.g.,
southern elephant seals, NARWs, Ziphiidae beaked whales, and bottlenose
dolphins) have been conducted and can be used to effectively forecast
longer-term, population-level impacts from behavioral changes. While
these are very specific models with very specific data requirements
that cannot yet be applied broadly to project-specific risk assessments
for the majority of species, they are a critical first step towards
being able to quantify the likelihood of a population level effect.
Since New et al. (2014), several publications have described models
developed to examine the long-term effects of environmental or
anthropogenic disturbance of foraging on various life stages of
selected species (e.g., sperm whale, Farmer et al., 2018; California
sea lion, McHuron et al., 2018; blue whale, Pirotta et al., 2018a;
humpback whale, Dunlop et al., 2021). These models continue to add to
refinement of the approaches to the PCoD framework. Such models also
help identify what data inputs require further investigation. Pirotta
et al. (2018b) provides a review of the PCoD framework with details on
each step of the process and approaches to applying real data or
simulations to achieve each step.
Despite its simplicity, there are few complete PCoD models
available for any marine mammal species due to a lack of data available
to parameterize many of the steps. To date, no PCoD model has been
fully parameterized with empirical data (Pirotta et al., 2018a) due to
the fact they are data intensive and logistically challenging to
complete. Therefore, most complete PCoD models include simulations,
theoretical modeling, and expert opinion to move through the steps. For
example, PCoD models have been developed to evaluate the effect of wind
farm construction on the North Sea harbor porpoise populations (e.g.,
King et al., 2015; Nabe-Nielsen et al., 2018). These models include a
mix of empirical data, expert elicitation (King et al., 2015) and
simulations of animals' movements, energetics, and/or survival (New et
al., 2014; Nabe-Nielsen et al., 2018).
PCoD models may also be approached in different manners. Dunlop et
al. (2021) modeled migrating humpback whale mother-calf pairs in
response to seismic surveys using both a forwards and backwards
approach. While a typical forwards approach can determine if a stressor
would have population-level consequences, Dunlop et al. demonstrated
that working backwards through a PCoD model can be used to assess the
most unfavorable scenario for an interaction of a target species and
stressor. This method may be useful for future management goals when
appropriate data becomes available to fully support the model. In
another example, harbor porpoise PCoD model investigating the impact of
seismic surveys on harbor porpoise included an investigation on
underlying drivers of vulnerability. Harbor porpoise movement and
foraging were modeled for baseline periods and then for periods with
seismic surveys as well; the models demonstrated that temporal (i.e.,
seasonal) variation in individual energetics and their link to costs
associated with disturbances was key in predicting population impacts
(Gallagher et al., 2021).
Behavioral change, such as disturbance manifesting in lost foraging
time, in response to anthropogenic activities is often assumed to
indicate a biologically significant effect on a population of concern.
However, as described above, individuals may be able to compensate for
some types and degrees of shifts in behavior, preserving their health
and thus their vital rates and population dynamics. For example,
[[Page 31031]]
New et al. (2013) developed a model simulating the complex social,
spatial, behavioral, and motivational interactions of coastal
bottlenose dolphins in the Moray Firth, Scotland, to assess the
biological significance of increased rate of behavioral disruptions
caused by vessel traffic. Despite a modeled scenario in which vessel
traffic increased from 70 to 470 vessels a year (a six-fold increase in
vessel traffic) in response to the construction of a proposed offshore
renewables' facility, the dolphins' behavioral time budget, spatial
distribution, motivations, and social structure remain unchanged.
Similarly, two bottlenose dolphin populations in Australia were also
modeled over 5 years against a number of disturbances (Reed et al.,
2020), and results indicated that habitat/noise disturbance had little
overall impact on population abundances in either location, even in the
most extreme impact scenarios modeled.
By integrating different sources of data (e.g., controlled exposure
data, activity monitoring, telemetry tracking, and prey sampling) into
a theoretical model to predict effects from sonar on a blue whale's
daily energy intake, Pirotta et al. (2021) found that tagged blue
whales' activity budgets, lunging rates, and ranging patterns caused
variability in their predicted cost of disturbance. This method may be
useful for future management goals when appropriate data becomes
available to fully support the model. Harbor porpoise movement and
foraging were modeled for baseline periods and then for periods with
seismic surveys as well; the models demonstrated that the seasonality
of the seismic activity was an important predictor of impact (Gallagher
et al., 2021).
In their table 1, Keen et al. (2021) summarize the emerging themes
in PCoD models that should be considered when assessing the likelihood
and duration of exposure and the sensitivity of a population to
disturbance (see table 1 from Keen et al., 2021, below). The themes are
categorized by life history traits (movement ecology, life history
strategy, body size, and pace of life), disturbance source
characteristics (overlap with biologically important areas, duration
and frequency, and nature and context), and environmental conditions
(natural variability in prey availability and climate change). Keen et
al. (2021) then summarize how each of these features influence an
assessment, noting, for example, that individual animals with small
home ranges have a higher likelihood of prolonged or year-round
exposure, that the effect of disturbance is strongly influenced by
whether it overlaps with biologically important habitats when
individuals are present, and that continuous disruption will have a
greater impact than intermittent disruption.
Nearly all PCoD studies and experts agree that infrequent exposures
of a single day or less are unlikely to impact individual fitness, let
alone lead to population level effects (Booth et al., 2016; Booth et
al., 2017; Christiansen and Lusseau, 2015; Farmer et al., 2018; Wilson
et al., 2020; Harwood and Booth, 2016; King et al., 2015; McHuron et
al., 2018; National Academies of Sciences, Engineering, and Medicine
(NAS), 2017; New et al., 2014; Pirotta et al., 2018a; Southall et al.,
2007; Villegas-Amtmann et al., 2015). As described through this notice
for the proposed IHA, NMFS expects that any behavioral disturbance that
would occur due to animals being exposed to construction activity would
be of a relatively short duration, with behavior returning to a
baseline state shortly after the acoustic stimuli ceases or the animal
moves far enough away from the source. Given this, and NMFS' evaluation
of the available PCoD studies, and the required mitigation discussed
later, any such behavioral disturbance resulting from Vineyard Wind's
activities is not expected to impact individual animals' health or have
effects on individual animals' survival or reproduction, thus no
detrimental impacts at the population level are anticipated. Marine
mammals may temporarily avoid the immediate area but are not expected
to permanently abandon the area or their migratory or foraging
behavior. Impacts to breeding, feeding, sheltering, resting, or
migration are not expected nor are shifts in habitat use, distribution,
or foraging success.
Potential Effects From Vessel Strike
Vessel collisions with marine mammals, also referred to as vessel
strikes or ship strikes, can result in death or serious injury of the
animal. Wounds resulting from ship strike may include massive trauma,
hemorrhaging, broken bones, or propeller lacerations (Knowlton and
Kraus, 2001). An animal at the surface could be struck directly by a
vessel, a surfacing animal could hit the bottom of a vessel, or an
animal just below the surface could be cut by a vessel's propeller.
Superficial strikes may not kill or result in the death of the animal.
Lethal interactions are typically associated with large whales, which
are occasionally found draped across the bulbous bow of large
commercial ships upon arrival in port. Although smaller cetaceans are
more maneuverable in relation to large vessels than are large whales,
they may also be susceptible to strike. 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; Conn and
Silber, 2013), although Kelley et al. (2020) found, through the use of
a simple biophysical model, that large whales can be seriously injured
or killed by vessels of all sizes. Impact forces increase with speed,
as does the probability of a strike at a given distance (Silber et al.,
2010; Gende et al., 2011).
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 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. Marine mammal
responses to vessels may include avoidance and changes in dive pattern
(NRC, 2003).
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 occurs and, if so, whether it results in
injury, serious injury, or mortality (Knowlton and Kraus, 2001; Laist
et al., 2001; Jensen and Silber, 2003; Pace and Silber, 2005;
Vanderlaan and Taggart, 2007; Conn and Silber, 2013). In assessing
records in which vessel speed was known, 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 13
kn.
Jensen and Silber (2003) detailed 292 records of known or probable
ship strikes of all large whale species from 1975 to 2002. Of these,
vessel speed at the time of collision was reported for 58 cases. Of
these 58 cases, 39 (or 67 percent) resulted in serious injury or death
(19 of those resulted in serious injury as determined by blood in the
water, propeller gashes or severed tailstock, and fractured skull, jaw,
vertebrae, hemorrhaging, massive bruising, or other injuries noted
during necropsy and 20 resulted in death). Operating speeds of vessels
that struck various species of large whales ranged from 2 to 51 kn. The
majority (79 percent) of these strikes occurred at speeds of 13 kn or
greater. The average speed that resulted in serious injury or death was
18.6 kn. Pace and Silber (2005) found that the probability of death or
serious injury increased rapidly with increasing vessel speed.
[[Page 31032]]
Specifically, the predicted probability of serious injury or death
increased from 45 to 75 percent as vessel speed increased from 10 to 14
kn and exceeded 90 percent at 17 kn. Higher speeds during collisions
result in greater force of impact and also appear to increase the
chance of severe injuries or death. While modeling studies have
suggested that hydrodynamic forces pulling whales toward the vessel
hull increase with increasing speed (Clyne, 1999; Knowlton et al.,
1995), this is inconsistent with Silber et al. (2010), which
demonstrated that there is no such relationship (i.e., hydrodynamic
forces are independent of speed).
In a separate study, Vanderlaan and Taggart (2007) analyzed the
probability of lethal mortality of large whales at a given speed,
showing that the greatest rate of change in the probability of a lethal
injury to a large whale as a function of vessel speed occurs between
8.6 and 15 kn. The chances of a lethal injury decline from
approximately 80 percent at 15 kn to approximately 20 percent at 8.6
kn. At speeds below 11.8 kn, the chances of lethal injury drop below 50
percent, while the probability asymptotically increases toward 100
percent above 15 kn.
The Jensen and Silber (2003) report notes that the Large Whale Ship
Strike Database represents a minimum number of collisions, because the
vast majority probably goes undetected or unreported. In contrast, the
Project's personnel are likely to detect any strike that does occur
because of the required personnel training and lookouts, along with the
inclusion of PSOs (as described in the Proposed Mitigation section),
and they are required to report all ship strikes involving marine
mammals.
There are no known vessel strikes of marine mammals by any offshore
wind energy vessel in the United States. Given the extensive mitigation
and monitoring measures (see the Proposed Mitigation and Proposed
Monitoring and Reporting section) that would be required of Vineyard
Wind, NMFS believes that a vessel strike is not likely to occur.
Potential Effects to Marine Mammal Habitat
Vineyard Wind's proposed activities could potentially affect marine
mammal habitat through impacts on the prey species of marine mammals
(through noise, oceanographic processes, or reef effects), acoustic
habitat (sound in the water column), water quality, and biologically
important habitat for marine mammals.
Effects on Prey
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, and 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 and Mann, 1999; Fay,
2009). The most likely effects on fishes exposed to loud, intermittent,
low-frequency sounds are behavioral responses (i.e., flight or
avoidance). Short duration, sharp sounds (such as pile driving or
airguns) can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to acoustic sources depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors. Key
impacts to fishes may include behavioral responses, hearing damage,
barotrauma (pressure-related injuries), and mortality. While it is
clear that the behavioral responses of individual prey, such as
displacement or other changes in distribution, can have direct impacts
on the foraging success of marine mammals, the effects on marine
mammals of individual prey that experience hearing damage, barotrauma,
or mortality is less clear, though obviously population scale impacts
that meaningfully reduce the amount of prey available could have more
serious impacts.
Fishes, like other vertebrates, have a variety of different sensory
systems to glean information from ocean around them (Astrup and Mohl,
1993; Astrup, 1999; Braun and Grande, 2008; Carroll et al., 2017;
Hawkins and Johnstone, 1978; Ladich and Popper, 2004; Ladich and
Schulz-Mirbach, 2016; Mann, 2016; Nedwell et al., 2004; Popper et al.,
2003, 2005). 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) (terrestrial vertebrates generally
only detect pressure). Most marine fishes primarily detect particle
motion using the inner ear and lateral line system while some fishes
possess additional morphological adaptations or specializations that
can enhance their sensitivity to sound pressure, such as a gas-filled
swim bladder (Braun and Grande, 2008; Popper and Fay, 2011).
Hearing capabilities vary considerably between different fish
species with data only available for just over 100 species out of the
34,000 marine and freshwater fish species (Eschmeyer and Fong, 2016).
In order to better understand acoustic impacts on fishes, fish hearing
groups are defined by species that possess a similar continuum of
anatomical features, which result in varying degrees of hearing
sensitivity (Popper and Hastings, 2003). There are four hearing groups
defined for all fish species (modified from Popper et al., 2014) within
this analysis, and they include: fishes without a swim bladder (e.g.,
flatfish, sharks, rays, etc.); fishes with a swim bladder not involved
in hearing (e.g., salmon, cod, pollock, etc.); fishes with a swim
bladder involved in hearing (e.g., sardines, anchovy, herring, etc.);
and fishes with a swim bladder involved in hearing and high-frequency
hearing (e.g., shad and menhaden). Most marine mammal fish prey species
would not be likely to perceive or hear mid- or high-frequency sonars.
While hearing studies have not been done on sardines and northern
anchovies, it would not be unexpected for them to have hearing
similarities to Pacific herring (up to 2-5 kHz) (Mann et al., 2005).
Currently, less data are available to estimate the range of best
sensitivity for fishes without a swim bladder.
In terms of physiology, multiple scientific studies have documented
a lack of mortality or physiological effects to fish from exposure to
low- and mid-frequency sonar and other sounds (Halvorsen et al., 2012a;
J[oslash]rgensen et al., 2005; Juanes et al., 2017; Kane et al., 2010;
Kvadsheim and Sevaldsen, 2005; Popper et al., 2007, 2016; Watwood et
al., 2016). Techer et al. (2017) exposed carp in floating cages for up
to 30 days to low-power 23 and 46 kHz source without any significant
physiological response. Other studies have documented either a lack of
TTS in species whose hearing range cannot perceive sonar (such as Navy
sonar), or for those species that could perceive sonar-like signals,
any TTS experienced would be recoverable (Halvorsen et al., 2012a;
Ladich and Fay, 2013; Popper and Hastings, 2009a, 2009b; Popper et al.,
2014; Smith, 2016). Only fishes that have specializations that enable
them to hear sounds above about 2,500 Hz (2.5 kHz), such as herring
(Halvorsen et al., 2012a; Mann et al., 2005; Mann, 2016; Popper et al.,
2014), would have the potential to receive TTS or exhibit behavioral
responses from exposure to
[[Page 31033]]
mid-frequency sonar. In addition, any sonar induced TTS to fish whose
hearing range could perceive sonar would only occur in the narrow
spectrum of the source (e.g., 3.5 kHz) compared to the fish's total
hearing range (e.g., 0.01 to 5 kHz).
In terms of behavioral responses, Juanes et al. (2017) discuss the
potential for negative impacts from anthropogenic noise on fish, but
the authors' focus was on broader based sounds, such as ship and boat
noise sources. Watwood et al. (2016) also documented no behavioral
responses by reef fish after exposure to mid-frequency active sonar.
Doksaeter et al. (2009, 2012) reported no behavioral responses to mid-
frequency sonar (such as naval sonar) by Atlantic herring;
specifically, no escape reactions (vertically or horizontally) were
observed in free swimming herring exposed to mid-frequency sonar
transmissions. Based on these results (Doksaeter et al., 2009, 2012;
Sivle et al., 2012), Sivle et al. (2014) created a model in order to
report on the possible population-level effects on Atlantic herring
from active sonar. The authors concluded that the use of sonar poses
little risk to populations of herring regardless of season, even when
the herring populations are aggregated and directly exposed to sonar.
Finally, Bruintjes et al. (2016) commented that fish exposed to any
short-term noise within their hearing range might initially startle but
would quickly return to normal behavior.
Pile driving noise during construction is of particular concern as
the very high sound pressure levels could potentially prevent fish from
reaching breeding or spawning sites, finding food, and acoustically
locating mates. A playback study in west Scotland revealed that there
was a significant movement response to the pile driving stimulus in
both species at relatively low received sound pressure levels (sole:
144-156 dB re 1[mu]Pa Peak; cod: 140-161 dB re 1 [mu]Pa Peak, particle
motion between 6.51 x 10\3\ and 8.62 x 10\4\ m/s\2\ peak) (Mueller-
Blenkle et al., 2010). The swimming speed of sole increased
significantly during the playback of construction noise when compared
to the playbacks of before and after construction. While not
statistically significant, cod also displayed a similar behavioral
response during before, during, and after construction playbacks.
However, cod demonstrated a specific and significant freezing response
at the onset and cessation of the playback recording. In both species,
indications were present displaying directional movements away from the
playback source. During wind farm construction in the eastern Taiwan
Strait, type 1 soniferous fish chorusing showed a relatively lower
intensity and longer duration while type 2 chorusing exhibited higher
intensity and no changes in its duration. Deviation from regular fish
vocalization patterns may affect fish reproductive success, cause
migration, augmented predation, or physiological alterations.
Occasional behavioral reactions to activities that produce
underwater noise sources are unlikely to cause long-term consequences
for individual fish or populations. The most likely impact to fish from
impact and vibratory pile driving activities at the LIAs would be
temporary behavioral avoidance of the area. 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. The
duration of fish avoidance of an area after pile driving stops 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 individual pile driving events and the
relatively small areas being affected.
Occasional behavioral reactions to activities that produce
underwater noise sources are unlikely to cause long-term consequences
for individual fish or populations. The most likely impact to fish from
impact pile driving activities at the LIA would be temporary behavioral
avoidance of the area. 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. The duration of
fish avoidance of an area after pile driving stops 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 individual pile driving events and the relatively small
areas being affected.
As described in the Proposed Mitigation section below, Vineyard
Wind would utilize a sound attenuation device which would reduce
potential for injury to marine mammal prey. Other fish that experience
hearing loss as a result of exposure to impulsive sound sources may
have a reduced ability to detect relevant sounds such as predators,
prey, or social vocalizations. However, PTS has not been known to occur
in fishes and any hearing loss in fish may be as temporary as the
timeframe required to repair or replace the sensory cells that were
damaged or destroyed (Popper et al., 2005, 2014; Smith, 2006). It is
not known if damage to auditory nerve fibers could occur, and if so,
whether fibers would recover during this process. In addition, most
acoustic effects, if any, are expected to be short-term and localized.
Long-term consequences for fish populations, including key prey species
within the LIA, would not be expected.
Required soft-starts would allow prey and marine mammals to move
away from the source prior to any noise levels that may physically
injure prey and the use of the noise attenuation devices would reduce
noise levels to the degree any mortality or injury of prey is also
minimized. Use of bubble curtains, in addition to reducing impacts to
marine mammals, for example, is a key mitigation measure in reducing
injury and mortality of ESA-listed salmon on the U.S. west coast.
However, we recognize some mortality, physical injury and hearing
impairment in marine mammal prey may occur, but we anticipate the
amount of prey impacted in this manner is minimal compared to overall
availability. Any behavioral responses to pile driving by marine mammal
prey are expected to be brief. We expect that other impacts, such as
stress or masking, would occur in fish that serve as marine mammals
prey (Popper et al., 2019); however, those impacts would be limited to
the duration of impact pile driving, and, if prey were to move out the
area in response to noise, these impacts would be minimized.
In addition to fish, prey sources such as marine invertebrates
could potentially be impacted by noise stressors as a result of the
proposed activities. However, most marine invertebrates' ability to
sense sounds is limited. Invertebrates appear to be able to detect
sounds (Pumphrey, 1950; Frings and Frings, 1967) and are most sensitive
to low-frequency sounds (Packard et al., 1990; Budelmann and
Williamson, 1994; Lovell et al., 2005; Mooney et al., 2010). Data on
response of invertebrates such as squid, another marine mammal prey
species, to anthropogenic sound is more limited (de Soto, 2016; Sole et
al., 2017). Data suggest that cephalopods are capable of sensing the
particle motion of sounds and detect low frequencies up to 1-1.5 kHz,
depending on the species, and so are likely to detect airgun noise
(Kaifu et al., 2008; Hu et al., 2009; Mooney et al., 2010; Samson et
al., 2014). Sole et al. (2017) reported physiological injuries to
cuttlefish in cages placed at-sea when exposed during a controlled
exposure experiment to low-frequency sources (315 Hz, 139 to 142 dB re
1 [mu]Pa\2\; 400 Hz, 139 to 141 dB re 1 [mu]Pa\2\).
[[Page 31034]]
Fewtrell and McCauley (2012) reported squids maintained in cages
displayed startle responses and behavioral changes when exposed to
seismic airgun sonar (136-162 re 1 [mu]Pa\2\ x s). Jones et al. (2020)
found that when squid (Doryteuthis pealeii) were exposed to impulse
pile driving noise, body pattern changes, inking, jetting, and startle
responses were observed and nearly all squid exhibited at least one
response. However, these responses occurred primarily during the first
eight impulses and diminished quickly, indicating potential rapid,
short-term habituation.
Cephalopods have a specialized sensory organ inside the head called
a statocyst that may help an animal determine its position in space
(orientation) and maintain balance (Budelmann, 1992). Packard et al.
(1990) showed that cephalopods were sensitive to particle motion, not
sound pressure, and Mooney et al. (2010) demonstrated that squid
statocysts act as an accelerometer through which particle motion of the
sound field can be detected. Auditory injuries (lesions occurring on
the statocyst sensory hair cells) have been reported upon controlled
exposure to low-frequency sounds, suggesting that cephalopods are
particularly sensitive to low-frequency sound (Andre et al., 2011; Sole
et al., 2013). Behavioral responses, such as inking and jetting, have
also been reported upon exposure to low-frequency sound (McCauley et
al., 2000; Samson et al., 2014). Squids, like most fish species, are
likely more sensitive to low-frequency sounds and may not perceive mid-
and high-frequency sonars.
With regard to potential impacts on zooplankton, McCauley et al.
(2017) found that exposure to airgun noise resulted in significant
depletion for more than half the taxa present and that there were two
to three times more dead zooplankton after airgun exposure compared
with controls for all taxa, within 1 km (0.6 mi) of the airguns.
However, the authors also stated that in order to have significant
impacts on r-selected species (i.e., those with high growth rates and
that produce many offspring) such as plankton, the spatial or temporal
scale of impact must be large in comparison with the ecosystem
concerned, and it is possible that the findings reflect avoidance by
zooplankton rather than mortality (McCauley et al., 2017). In addition,
the results of this study are inconsistent with a large body of
research that generally finds limited spatial and temporal impacts to
zooplankton as a result of exposure to airgun noise (e.g., Dalen and
Knutsen, 1987; Payne, 2004; Stanley et al., 2011). Most prior research
on this topic, which has focused on relatively small spatial scales,
has showed minimal effects (e.g., Kostyuchenko, 1973; Booman et al.,
1996; S[aelig]tre and Ona, 1996; Pearson et al., 1994; Bolle et al.,
2012).
A modeling exercise was conducted as a follow-up to the McCauley et
al. (2017) study (as recommended by McCauley et al., 2017), in order to
assess the potential for impacts on ocean ecosystem dynamics and
zooplankton population dynamics (Richardson et al., 2017). Richardson
et al. (2017) found that a full-scale airgun survey would impact
copepod abundance within the survey area, but that effects at a
regional scale were minimal (2 percent decline in abundance within 150
km (93.2 mi) of the survey area and effects not discernible over the
full region). The authors also found that recovery within the survey
area would be relatively quick (3 days following survey completion) and
suggest that the quick recovery was due to the fast growth rates of
zooplankton, and the dispersal and mixing of zooplankton from both
inside and outside of the impacted region. The authors also suggest
that surveys in areas with more dynamic ocean circulation in comparison
with the study region and/or with deeper waters (i.e., typical offshore
wind locations) would have less net impact on zooplankton.
Notably, a recently described study produced results inconsistent
with those of McCauley et al. (2017). Researchers conducted a field and
laboratory study to assess if exposure to airgun noise affects
mortality, predator escape response, or gene expression of the copepod
Calanus finmarchicus (Fields et al., 2019). Immediate mortality of
copepods was significantly higher, relative to controls, at distances
of 5 m or less from the airguns. Mortality 1 week after the airgun
blast was significantly higher in the copepods placed 10 m from the
airgun but was not significantly different from the controls at a
distance of 20 m from the airgun. The increase in mortality, relative
to controls, did not exceed 30 percent at any distance from the airgun.
Moreover, the authors caution that even this higher mortality in the
immediate vicinity of the airguns may be more pronounced than what
would be observed in free-swimming animals due to increased flow speed
of fluid inside bags containing the experimental animals. There were no
sub-lethal effects on the escape performance, or the sensory threshold
needed to initiate an escape response, at any of the distances from the
airgun that were tested. Whereas McCauley et al. (2017) reported an SEL
of 156 dB at a range of 509-658 m, with zooplankton mortality observed
at that range, Fields et al. (2019) reported an SEL of 186 dB at a
range of 25 m, with no reported mortality at that distance.
Airguns and impact pile driving are similar in that they both
produce impulsive and intermittent noise and typically have higher
source levels than other sources (e.g., vibratory driving). We
anticipate marine mammal prey exposed to impact pile driving would
demonstrate similar physical consequences and behavioral impacts
compared to exposure to airguns; however, the spatial extent of these
impacts during impact pile driving is dependent upon source levels and
use of noise attenuation systems (NAS) such as double bubble curtains,
such that lower source levels and use of NAS are expected to further
minimize impacts that would occur otherwise.
The presence of large numbers of turbines has been shown to impact
meso- and sub-meso-scale water column circulation, which can affect the
density, distribution, and energy content of zooplankton and thereby,
their availability as marine mammal prey. Topside, atmospheric wakes
result in wind speed reductions influencing upwelling and downwelling
in the ocean while underwater structures such as WTG and ESP
foundations may cause turbulent current wakes, which impact
circulation, stratification, mixing, and sediment resuspension (Daewel
et al., 2022). Overall, the presence of structures such as wind
turbines is, in general, likely to result in certain oceanographic
effects in the marine environment and may alter marine mammal prey,
such as aggregations and distribution of zooplankton through changing
the strength of tidal currents and associated fronts, changes in
stratification, primary production, the degree of mixing, and
stratification in the water column (Chen et al., 2021; Johnson et al.,
2021; Christiansen et al., 2022; Dorrell et al., 2022).
Turbine operations for the previously installed 47 WTG monopile
foundations commenced in 2023. Vineyard Wind intends to install 15 WTG
monopile foundations, and it is possible that turbines would become
operational by the end of the IHA effective period. As described below
(see Potential Effects from Offshore Wind Farm Operational Noise
section), there is scientific uncertainty around the scale of
oceanographic impacts (meters to kilometers) associated with turbine
operation. The Project is located offshore of Massachusetts, and
although the LIA does overlap with key winter
[[Page 31035]]
foraging grounds for NARWs (Leiter et al., 2017; Quintana-Rizzo et al.,
2021; O'Brien et al., 2022; Pendleton et al., 2022), nearby habitat may
provide higher foraging value should NARW prey be affected in the LIA
during construction, and the amount of pile driving time with only 15
piles remaining to be installed is expected to be limited, thereby
limiting potential impacts on prey aggregation. In addition, the
proposed seasonal restriction on pile driving from January through May
would reduce impacts to NARW prey during the time that they are more
likely to be foraging. The LIA does not overlap but is in proximity to
seasonal foraging grounds for fin whales, minke whales, and sei whales.
Generally speaking, and depending on the extent, impacts on prey could
impact the distribution of marine mammals in an area, potentially
necessitating additional energy expenditure to find and capture prey.
However, at the temporal and spatial scales anticipated for this
activity, any such impacts on prey are not expected to impact the
reproduction or survival of any individual marine mammals. Although
studies assessing the impacts of offshore wind development on marine
mammals are limited, the repopulation of wind energy areas by harbor
porpoises (Brandt et al., 2016; Lindeboom et al., 2011) and harbor
seals (Lindeboom et al., 2011; Russell et al., 2016) following the
installation of wind turbines are promising. Overall, any impacts to
marine mammal foraging capabilities due to effects on prey aggregation
from the turbine presence and operation during the effective period of
the proposed IHA is likely to be limited. In general, impacts to marine
mammal prey species are expected to be relatively minor and temporary
due to the expected short daily duration of individual pile driving
events and the relatively small areas being affected.
Reef Effects
The presence of monopile foundations and scour protection will
result in a conversion of the existing sandy bottom habitat to a hard
bottom habitat with areas of vertical structural relief. This could
potentially alter the existing habitat by creating an ``artificial reef
effect'' that results in colonization by assemblages of both sessile
and mobile animals within the new hard-bottom habitat (Wilhelmsson et
al., 2006; Reubens et al., 2013; Bergstr[ouml]m et al., 2014; Coates et
al., 2014). This colonization by marine species, especially hard-
substrate preferring species, can result in changes to the diversity,
composition, and/or biomass of the area thereby impacting the trophic
composition of the site (Wilhelmsson et al., 2010; Krone et al., 2013;
Bergstr[ouml]m et al., 2014; Hooper et al., 2017; Raoux et al., 2017;
Harrison and Rousseau, 2020; Taormina et al., 2020; Buyse et al.,
2022a; ter Hofstede et al., 2022).
Artificial structures can create increased habitat heterogeneity
important for species diversity and density (Langhamer, 2012). The
monopile WTG foundations will extend through the water column, which
may serve to increase settlement of meroplankton or planktonic larvae
on the structures in both the pelagic and benthic zones (Boehlert and
Gill, 2010). Fish and invertebrate species are also likely to aggregate
around the foundations and scour protection which could provide
increased prey availability and structural habitat (Boehlert and Gill,
2010; Bonar et al., 2015). Further, instances of species previously
unknown, rare, or nonindigenous to an area have been documented at
artificial structures, changing the composition of the food web and
possibly the attractability of the area to new or existing predators
(Adams et al., 2014; de Mesel, 2015; Bishop et al., 2017; Hooper et
al., 2017; Raoux et al., 2017; van Hal et al., 2017; Degraer et al.,
2020; Fernandez-Betelu et al., 2022). Notably, there are examples of
these sites becoming dominated by marine mammal prey species, such as
filter-feeding species and suspension-feeding crustaceans (Andersson
and [Ouml]hman, 2010; Slavik et al., 2019; Hutchison et al., 2020; Pezy
et al., 2020; Mavraki et al., 2022).
Numerous studies have documented significantly higher fish
concentrations including species like cod and pouting (Trisopterus
luscus), flounder (Platichthys flesus), eelpout (Zoarces viviparus),
and eel (Anguilla anguilla) near in-water structures than in
surrounding soft bottom habitat (Langhamer and Wilhelmsson, 2009;
Bergstr[ouml]m et al., 2013; Reubens et al., 2013). In the German Bight
portion of the North Sea, fish were most densely congregated near the
anchorages of jacket foundations, and the structures extending through
the water column were thought to make it more likely that juvenile or
larval fish encounter and settle on them (Rhode Island Coastal
Resources Management Council, 2010; Krone et al., 2013). In addition,
fish can take advantage of the shelter provided by these structures
while also being exposed to stronger currents created by the
structures, which generate increased feeding opportunities and
decreased potential for predation (Wilhelmsson et al., 2006). The
presence of the foundations and resulting fish aggregations around the
foundations is expected to be a long-term habitat impact, but the
increase in prey availability could potentially be beneficial for some
marine mammals.
Water Quality
Temporary and localized reduction in water quality will occur as a
result of pile driving activities. These activities will disturb bottom
sediments and may cause a temporary increase in suspended sediment in
the LIA. Currents should quickly dissipate any raised total suspended
sediment (TSS) levels, and levels should return to background levels
once the project activities in that area cease. No direct impacts on
marine mammals are anticipated due to increased TSS and turbidity;
however, turbidity within the water column has the potential to reduce
the level of oxygen in the water and irritate the gills of prey fish
species in the LIA. However, turbidity plumes associated with the
project would be temporary and localized, and fish in the LIA would be
able to move away from and avoid the areas where plumes may occur.
Therefore, it is expected that the impacts on prey fish species from
turbidity, and therefore on marine mammals, would be minimal and
temporary.
Equipment used by Vineyard Wind within the LIA, including ships and
other marine vessels, potentially aircrafts, and other equipment, are
also potential sources of by-products (e.g., hydrocarbons, particulate
matter, heavy metals). All equipment is properly maintained in
accordance with applicable legal requirements. All such operating
equipment meets Federal water quality standards, where applicable.
Given these requirements, impacts to water quality are expected to be
minimal.
Acoustic Habitat
Acoustic habitat is the soundscape, which encompasses all of the
sound present in a particular location and time, as a whole when
considered from the perspective of the animals experiencing it. Animals
produce sound for, or listen for sounds produced by, conspecifics
(communication during feeding, mating, and other social activities),
other animals (finding prey or avoiding predators), and the physical
environment (finding suitable habitats, navigating). Together, sounds
made by animals and the geophysical environment (e.g., produced by
earthquakes, lightning, wind, rain, waves) make up the natural
[[Page 31036]]
contributions to the total acoustics of a place. These acoustic
conditions, termed acoustic habitat, are one attribute of an animal's
total habitat.
Soundscapes are defined and influenced by the total contribution of
anthropogenic sound. This may include incidental emissions from sources
such as vessel traffic or may be intentionally introduced to the marine
environment for data acquisition purposes (as in the use of airgun
arrays) or for Navy training and testing purposes (as in the use of
sonar and explosives and other acoustic sources). Anthropogenic noise
varies widely in its frequency, content, duration, and loudness. These
characteristics greatly influence the potential habitat-mediated
effects to marine mammals (please also see the previous discussion on
Masking), which may range from local effects for brief periods of time
to chronic effects over large areas and for long durations. Depending
on the extent of effects to habitat, animals may alter their
communications signals (thereby potentially expending additional
energy) or miss acoustic cues (either conspecific or adventitious).
Problems arising from a failure to detect cues are more likely to occur
when noise stimuli are chronic and overlap with biologically relevant
cues used for communication, orientation, and predator/prey detection
(Francis and Barber, 2013). For more detail on these concepts, see:
Barber et al., 2009; Pijanowski et al., 2011; Francis and Barber, 2013;
Lillis et al., 2014.
The term ``listening area'' refers to the region of ocean over
which sources of sound can be detected by an animal at the center of
the space. Loss of communication space concerns the area over which a
specific animal signal, used to communicate with conspecifics in
biologically important contexts (e.g., foraging, mating), can be heard,
in noisier relative to quieter conditions (Clark et al., 2009). Lost
listening area concerns the more generalized contraction of the range
over which animals would be able to detect a variety of signals of
biological importance, including eavesdropping on predators and prey
(Barber et al., 2009). Such metrics do not, in and of themselves,
document fitness consequences for the marine animals that live in
chronically noisy environments. Long-term population-level consequences
mediated through changes in the ultimate survival and reproductive
success of individuals are difficult to study, and particularly so
underwater. However, it is increasingly well documented that aquatic
species rely on qualities of natural acoustic habitats, with
researchers quantifying reduced detection of important ecological cues
(e.g., Francis and Barber, 2013; Slabbekoorn et al., 2010) as well as
survivorship consequences in several species (e.g., Simpson et al.,
2014; Nedelec et al., 2014).
Potential Effects From Offshore Wind Farm Operational Noise
Although this proposed IHA primarily covers the noise produced from
construction activities relevant to the Vineyard Wind Offshore Wind
Project offshore wind facility, operational noise was a consideration
in NMFS' analysis of the project, as turbines may become operational
within the effective dates of the IHA (if issued).
In both newer, quieter, direct-drive systems and older generation,
geared turbine designs, recent scientific studies indicate that
operational noise from turbines is on the order of 110 to 125 dB re 1
[mu]Pa root-mean-square sound pressure level (SPLrms) at an
approximate distance of 50 m (Tougaard et al., 2020). Recent
measurements of operational sound generated from wind turbines (direct
drive, 6 MW, jacket foundations) at Block Island wind farm (BIWF)
indicate average broadband levels of 119 dB at 50 m from the turbine,
with levels varying with wind speed (HDR, Inc., 2019). Interestingly,
measurements from BIWF turbines showed operational sound had fewer
tonal components compared to European measurements of turbines with
gear boxes.
Tougaard et al. (2020) further stated that the operational noise
produced by WTGs is static in nature and lower than noise produced by
passing ships. This is a noise source in this region to which marine
mammals are likely already habituated. Furthermore, operational noise
levels are likely lower than those ambient levels already present in
active shipping lanes, such that operational noise would likely only be
detected in very close proximity to the WTG (Thomsen et al., 2006;
Tougaard et al., 2020). Similarly, recent measurements from a wind farm
(3-MW turbines) in China found that above 300 Hz, turbines produced
sound that was similar to background levels (Zhang et al., 2021). Other
studies by Jansen and de Jong (2016) and Tougaard et al. (2009)
determined that, while marine mammals would be able to detect
operational noise from offshore wind farms (again, based on older 2-MW
models) for several kilometers, they expected no significant impacts on
individual survival, population viability, marine mammal distribution,
or the behavior of the animals considered in their study (harbor
porpoises and harbor seals). In addition, Madsen et al. (2006) found
the intensity of noise generated by operational wind turbines to be
much less than the noises present during construction, although this
observation was based on a single turbine with a maximum power of 2 MW.
More recently, St[ouml]ber and Thomsen (2021) used monitoring data
and modeling to estimate noise generated by more recently developed,
larger (10-MW) direct-drive WTGs. Their findings, similar to Tougaard
et al. (2020), demonstrate that there is a trend that operational noise
increases with turbine size. Their study predicts broadband source
levels could exceed 170-dB SPLrms for a 10-MW WTG; however,
those noise levels were generated based on geared turbines whereas
newer turbines operate with direct drive technology. The shift from
using gear boxes to direct drive technology is expected to reduce the
levels by 10 dB. The findings in the St[ouml]ber and Thomsen (2021)
study have not been experimentally validated, though the modeling
(using largely geared turbines) performed by Tougaard et al. (2020)
yields similar results for a hypothetical 10-MW WTG.
Recently, Holme et al. (2023) cautioned that the Tougaard et al.
(2020) and St[ouml]ber and Thomsen (2021) studies extrapolated levels
for larger turbines should be interpreted with caution since both
studies relied on data from smaller turbines (0.45 to 6.15 MW)
collected over a variety of environmental conditions. Holme et al.
(2023) demonstrated that the model presented in Tougaard et al. (2020)
tends to potentially overestimate levels (up to approximately 8 dB)
measured to those in the field, especially with measurements closer to
the turbine for larger turbines. Holme et al. (2023) measured
operational noise from larger turbines (6.3 and 8.3 MW) associated with
three wind farms in Europe and found no relationship between turbine
activity (power production, which is proportional to the blade's
revolutions per minute) and noise level, though it was noted that this
missing relationship may have been masked by the area's relatively high
ambient noise sound levels. Sound levels (rms) of a 6.3-MW direct-drive
turbine were measured to be 117.3 dB at a distance of 70 m. However,
measurements from 8.3 MW turbines were inconclusive as turbine noise
was deemed to have been largely masked by ambient noise.
Finally, operational turbine measurements are available from the
Coastal Virginia Offshore Wind (CVOW)
[[Page 31037]]
pilot pile project, where two 7.8 m monopile WTGs were installed (HDR,
2023). Compared to BIWF, levels at CVOW were higher (10-30 dB) below
120 Hz, believed to be caused by the vibrations associated with the
monopile structure, while above 120 Hz levels were consistent among the
two wind farms.
Overall, noise from operating turbines would raise ambient noise
levels in the immediate vicinity of the turbines; however, the spatial
extent of increased noise levels would be limited. Vineyard Wind did
not request, and NMFS is not proposing to authorize, take incidental to
operational noise from WTGs. Therefore, the topic is not discussed or
analyzed further herein. However, NMFS proposes to require Vineyard
Wind to measure operational noise levels.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization through the IHA, which will inform NMFS'
consideration of ``small numbers,'' the negligible impact
determinations, and impacts on subsistence uses.
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).
Proposed takes would primarily be by Level B harassment, as noise
from pile driving has the potential to result in disruption of marine
mammal behavioral patterns. Impacts such as masking and TTS can
contribute to the disruption of behavioral patterns and are accounted
for within those takes proposed for authorization. There is also some
potential for high frequency species (harbor porpoise) and phocids
(harbor seal and gray seal) to experience a limited amount of auditory
injury (PTS; Level A harassment) primarily because predicted auditory
injury zones are large enough and these species are cryptic enough that
the potential for PTS cannot be fully discounted. For mysticetes, the
Level A harassment ER95percent ranges are also large (0.0043
km to 3.191 km); however, the extensive marine mammal mitigation and
monitoring proposed by Vineyard Wind, and which would be required by
NMFS, as well as natural avoidance behaviors is expected to reduce the
potential for PTS to discountable levels. Nevertheless, Vineyard Wind
has requested, and NMFS proposes to authorize a small amount of Level A
harassment incidental to installing piles (table 11). Auditory injury
is unlikely to occur for mid-frequency species as thresholds are higher
and PTS zones are very close to the pile such that PTS is unlikely to
occur. While NMFS is proposing to authorize Level A harassment and
Level B harassment, the proposed mitigation and monitoring measures are
expected to, in some cases, avoid,and minimize overall the severity of
the taking to the extent practicable (see Proposed Mitigation and
Proposed Monitoring and Reporting sections).
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized incidental to the specified
activity. Even without mitigation, pile driving activities are unlikely
to directly cause marine mammal mortality or serious injury. There is
no documented case wherein pile driving resulted in marine mammal
mortality or stranding and the scientific literature demonstrates that
the most likely behavioral response to pile driving (or similar
stimulus source) is avoidance and temporary cessation of behaviors such
as foraging or socialization (see Avoidance and Displacement in
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat section). While, in general, there is a low probability that
mortality or serious injury of marine mammals could occur from vessel
strikes, the mitigation and monitoring measures contained within this
proposed rule are expected to avoid vessel strikes (see Proposed
Mitigation section). No other activities have the potential to result
in mortality or serious injury.
For acoustic impacts, we estimate take by considering: (1) acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
the number of days of activities. We note that while these factors can
contribute to a basic calculation to provide an initial prediction of
potential 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 estimates.
As described below, there are multiple methods available to
estimate the density or number of a given species in the area
appropriate to inform the take estimate. For each species and activity,
the largest value resulting from the three take estimation methods
described below (i.e., density-based, PSO-based, or mean group size)
was carried forward as the amount of take proposed for authorization,
by Level B harassment. The amount of take proposed for authorization,
by Level A harassment, reflects the density-based exposure estimates
and, for some species and activities, consideration of other data such
as mean group size.
Below, we describe NMFS' acoustic thresholds, acoustic and exposure
modeling methodologies, marine mammal density calculation methodology,
occurrence information, and the modeling and methodologies applied to
estimate take for the Project's proposed construction activities. NMFS
considered all information and analysis presented by Vineyard Wind, as
well as all other applicable information and, based on the best
available science, concurs that the estimates of the types and amounts
of take for each species and stock are reasonable, and is proposing to
authorize the amount requested. NMFS notes the take estimates described
herein for foundation installation can be considered conservative
because the estimates do not reflect the implementation of clearance
and shutdown zones for any marine mammal species or stock.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
are likely to be behaviorally harassed (Level B harassment) or to incur
PTS of some degree (Level A harassment). A summary of all NMFS'
thresholds can be found at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Level B Harassment
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 or
exposure context (e.g., frequency, predictability, duty cycle, duration
of the exposure, signal-to-noise
[[Page 31038]]
ratio, distance to the source, ambient noise, and the receiving
animal's hearing, motivation, experience, demography, behavior at time
of exposure, life stage, depth) and can be difficult to predict (e.g.,
Southall et al., 2007, 2021; Ellison et al., 2012). Based on what the
available science indicates and the practical need to use a threshold
based on a metric that is both predictable and measurable for most
activities, NMFS typically uses a generalized acoustic threshold based
on received level to estimate the onset of behavioral harassment.
NMFS generally predicts that marine mammals are likely to be taken
in a manner considered to be Level B harassment when exposed to
underwater anthropogenic noise above root-mean-squared pressure
received levels (RMS SPL) of 120 dB (referenced to 1 micropascal (re 1
[mu]Pa)) for continuous (e.g., vibratory pile driving, drilling) and
above RMS SPL 160 dB re 1 [mu]Pa for non-explosive impulsive (e.g.,
seismic airguns) or intermittent (e.g., scientific sonar) sources.
Generally speaking, Level B harassment take estimates based on these
thresholds are expected to include any likely takes by TTS as, in most
cases, the likelihood of TTS occurs at closer distances from the
source. TTS of a sufficient degree can manifest as behavioral
harassment, as reduced hearing sensitivity and the potential reduced
opportunities to detect important signals (conspecific communication,
predators, prey) may result in changes in behavior patterns that would
not otherwise occur.
The proposed Project's construction activities include the use of
impulsive sources (e.g., impact pile driving), and therefore the 160-dB
re 1 [mu]Pa (rms) threshold is applicable to our analysis.
Level A Harassment
NMFS' Technical Guidance for Assessing the Effects of Anthropogenic
Sound on Marine Mammal Hearing (Version 2.0, Technical Guidance; NMFS,
2018) identifies dual criteria to assess auditory injury (Level A
harassment) to five different marine mammal groups (based on hearing
sensitivity) as a result of exposure to noise from two different types
of sources (impulsive or non-impulsive). 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). As described above, Vineyard Wind's proposed
activities include the use of impulsive sources. NMFS' thresholds
identifying the onset of PTS are provided in table 5. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 5--PTS Onset Thresholds
[NMFS, 2018]
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Lp,0-pk,flat: 219 dB; LE,p, LF,24h: 199 dB.
LE,p, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Lp,0-pk,flat: 230 dB; LE,p, MF,24h: 198 dB.
LE,p, MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Lp,0-pk,flat: 202 dB; LE,p, HF,24h: 173 dB.
LE,p,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Lp,0-pk,flat: 218 dB; LE,p,PW,24h: 201 dB.
LE,p,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Lp,0-pk,flat: 232 dB; LE,p,OW,24h: 219 dB.
LE,p,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to be
more reflective of International Organization for Standardization standards (ISO, 2017). The subscript
``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the
generalized hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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
weighted 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 thresholds will be exceeded.
Below, we describe the assumptions and methodologies used to
estimate take, in consideration of acoustic thresholds and appropriate
marine mammals density and occurrence information, for WTG monopile
installation. Resulting distances to thresholds, densities and
occurrence (i.e., PSO sightings, group size) data used, exposure
estimates (as relevant to the analysis), and activity-specific take
estimates can be found below.
Acoustic and Exposure Modeling
During the 2023 Vineyard Wind pile installation activities,
Vineyard Wind conducted a sound field verification (SFV) study to
compare with model results of the 2018 modeling (K[uuml]sel et al.,
2024). The SFV study included acoustic monitoring of the impact
installation of 12 monopile foundations from June 6 through September
7, 2023. Five of the 12 acoustically monitored monopiles were
determined to be representative of the noise attenuation system (NAS)
configuration and maintenance schedule that would be proposed for the
remaining 15 monopiles to be installed in 2024. These five
representative monopiles (piles 7, 8, 10, 11, and 12 in the Vineyard
Wind SFV Monitoring Report) were monitored using a double bubble
curtain (DBBC) and Hydrosound Damper System (HSD), which has been
proposed for use as the noise attenuation system setup for the
remaining 15 monopiles. Vineyard Wind also followed an enhanced bubble
curtain maintenance schedule for these five monopiles; this maintenance
schedule would also be used for the remaining 15 monopiles to be
installed in 2024 (see the Vineyard Wind Enhanced BBC Technical Memo).
Peak (pk), SEL, and RMS SPL received distances for each acoustically
monitored pile are reported in the VW1 SFV Final Report Appendix A
(K[uuml]sel et al., 2024) For additional details on how acoustic ranges
were derived from SFV measurements, see the VW1 SFV Final Report
sections 2.3 and 3.3 (K[uuml]sel et al., 2024). JASCO modeled a maximum
[[Page 31039]]
range to the Level A harassment threshold of 3.191 km (1.99 mi) with 6-
dB attenuation (for low-frequency cetaceans) (K[uuml]sel et al., 2024).
In addition to the 15 piles being installed under the same noise
attenuation scenario as the 5 aforementioned representative piles, they
are also anticipated to be installed under similar pile driving
specifications and in a similar acoustic environment. Table 6 describes
the key piling assumptions and proposed impact pile driving schedule
for 2024. These assumptions and schedule are based upon the 2023 piling
and hammer energy schedule for installing monopiles. Vineyard Wind
expects installation of the 15 remaining piles will necessitate similar
operations. Further, as described in detail in section 6.1 of Vineyard
Wind's application, the water depth and bottom type are similar
throughout the Lease Area and therefore sound propagation in the LIA is
not expected to differ from where the SFV data were collected in 2023.
Table 6--Key Piling Assumptions and Hammer Energy Schedule for Monopile Installation
----------------------------------------------------------------------------------------------------------------
Max piling
Pile type Project component Max hammer Number of time duration Number
energy (kJ) hammer strikes per pile (min) piles/day
----------------------------------------------------------------------------------------------------------------
9.6-m monopile............... WTG................ 4,000 2,884-4,329 117 1
(average
3,463) \a\.
----------------------------------------------------------------------------------------------------------------
\a\ The number of hammer strikes represent the range of strikes needed to install the 12 monopiles for which SFV
was conducted in 2023.
Vineyard Wind compared the acoustic ranges to the Level A
harassment and Level B harassment thresholds derived from the 2018
acoustic modeling (Py[cacute] et al., 2018) to the maximum ranges with
absorption for the five representative monopiles acoustically monitored
in 2023. They applied the greater results to the analysis in their
application and NMFS has included that approach in this proposed IHA.
The maximum measured range to PTS thresholds of the five representative
monopiles was less than the maximum 2018 modeled ranges for all hearing
groups, assuming 6 dB of attenuation (table 7), with the exception of
high-frequency cetaceans (although Vineyard Wind attributes this
extended range to non-piling noise (Vineyard Wind, 2023)). Therefore,
Vineyard Wind based the expected distance to the Level A harassment
threshold and associated estimated take analysis on the 2018 modeled
data.
Table 7--Modeled and Measured Ranges to SELcum PTS Thresholds for Marine
Mammal Hearing Groups
------------------------------------------------------------------------
Measured maximum
Modeled range to range to SELcum PTS
Marine mammal hearing group SELcum PTS threshold threshold (km) \b\
(km) \a\
------------------------------------------------------------------------
Low-frequency cetaceans..... 3.191 2.37
Mid-frequency cetaceans..... 0.043 0.01
High-frequency cetaceans.... 0.071 0.2
Phocid pinnipeds............ 0.153 0.1
------------------------------------------------------------------------
\a\ Based upon modeling conducted for the 2023 IHA (Py[cacute] et al.,
2018)
\b\ Based upon the five representative monopiles from the Vineyard Wind
2023 construction campaign (K[uuml]sel et al., 2024).
The maximum range with absorption to the Level B harassment
threshold for acoustically monitored piles was 5.72 km (3.6 mi) (pile
13, AU-38; K[uuml]sel et al., 2024), which was greater than the 2018
modeled distance to the Level B harassment threshold of 4.1 km (2.5 mi)
(Py[cacute] et al., 2018). Therefore, Vineyard Wind based the expected
distance to the Level B harassment threshold and associated estimated
take analysis on the 5.72-km acoustically monitored distance.
In 2018, Vineyard Wind conducted animat modeling to estimate take,
by Level A harassment (PTS), incidental to the project. In order to
best evaluate the SELcum harassment thresholds for PTS, it
is necessary to consider animal movement, as the results are based on
how sound moves through the environment between the source and the
receiver. Applying animal movement and behavior within the modeled
noise fields provides the exposure range, which allows for a more
realistic indication of the distances at which PTS acoustic thresholds
are reached that considers the accumulation of sound over different
durations (note that in all cases the distance to the peak threshold is
less than the SEL-based threshold). As described above, Vineyard Wind
based the Level A harassment estimated take analysis on the modeled
Level A harassment acoustic ranges and therefore appropriately used the
results of the JASCO's Animal Simulation Model Including Noise Exposure
(JASMINE) animal movement modeling conducted for the 2023 IHA (86 FR
33810, June 25, 2021). Sound exposure models like JASMINE use simulated
animals (also known as ``animats'') to forecast behaviors of animals in
new situations and locations based upon previously documented behaviors
of those animals. The predicted 3D sound fields (i.e., the output of
the acoustic modeling process described earlier) are sampled by animats
using movement rules derived from animal observations. The output of
the simulation is the exposure history for each animat within the
simulation. The precise location of animats and their pathways are not
known prior to a project; therefore, a repeated random sampling
technique (i.e., Monte Carlo) is used to estimate exposure probability
with many animats and randomized starting positions. The combined
exposure history of all animats gives a probability density function of
exposure during the Project.
Since the time that the JASMINE animal movement modeling was
conducted for the 2023 IHA (86 FR 33810, June 25, 2021), no new
behavior data is available that would have changed how animats move in
time and space in that model and, therefore, NMFS has determined that
the JASMINE outputs from the 2018 modeling effort are reasonable for
application here. However, the post processing calculations used more
recent density data (table 8). The mean
[[Page 31040]]
number of modeled animats exposed per day with installation of one 9.6-
m monopile were scaled by the maximum monthly density for the LIA
(Roberts et al., 2023) for each species (table 8) to estimate the real-
world number of animats of each species that could be exposed per day
in the LIA. This real-world number of animals was multiplied by the
expected number of days of pile installation (15 days) to derive a
total take estimate by Level A harassment for each species. The number
of potential exposures by Level A harassment was estimated for each
species using the following equation:
Density-based exposure estimate of Level A harassment = number of
animats exposed above the Level A harassment thresholdx ((mean maximum
monthly density (animals/km\2\)/modeled 2018 density (animats/
km\2\))xnumber of days (15).
To estimate the amount of take by Level B harassment incidental to
installing the remaining 15 piles, Vineyard Wind applied a static
method (i.e., did not conduct animal movement modeling). Vineyard Wind
calculated the Level B harassment ensonified area using the following
equation:
A = 3.14 x r\2\,
where A is equal to the ensonified area and r is equal to the radial
distance to the Level B harassment threshold from the pile driving
source (rLevel B harassment = 5.72 km).
The ensonified area (102.7 km\2\) was multiplied by the mean
maximum monthly density estimate (table 8) and expected number of days
of pile driving (15 days) to determine a density-based take estimate
for each species. The number of potential exposures by Level B
harassment was estimated for each species using the following equation:
Density-based exposure estimate of Level B harassment = ensonified area
(km\2\) x maximum mean monthly density estimate (animals/km\2\) x
number of days (15).
Density and Occurrence and Take Estimation
In this section we provide information about marine mammal density,
presence, and group dynamics that informed the take calculations for
the proposed activities. Vineyard Wind applied the 2022 Duke University
Marine Geospatial Ecology Laboratory Habitat-based Marine Mammal
Density Models for the U.S. Atlantic (Duke Model-Roberts et al., 2016,
2023) to estimate take from foundation installation. The models
estimate absolute density (individuals/km\2\) by statistically
correlating sightings reported on shipboard and aerial surveys with
oceanographic conditions. For most marine mammal species, densities are
provided on a monthly basis. Where monthly densities are not available
(e.g., pilot whales), annual densities are provided. Moreover, some
species are represented as guilds (e.g., seals (representing Phocidae
spp., primarily harbor and gray seals) and pilot whales (representing
short-finned and long-finned pilot whales)).
The Duke habitat-based density models delineate species' density
into 5 x 5 km (3.1 x 3.1 mi) grid cells. Vineyard Wind calculated mean
monthly densities by using a 10-km buffered polygon around the
remaining WTG foundations to be installed and overlaying this buffered
polygon on the density maps. The 10-km buffer defines the area around
the LIA used to calculate mean species density. Mean monthly density
for each species was determined by calculating the unweighted mean of
all 5 x 5 km grid cells (partially or fully) within the buffered
polygon. The unweighted mean refers to using the entire 5 x 5 km (3.1 x
3.1 mi) grid cell for each cell used in the analysis, and was not
weighted by the proportion of the cell overlapping with the density
perimeter if the entire grid cell was not entirely within the buffer
zone polygon. Vineyard Wind calculated densities for each month, except
for species for which annual density data only was available (e.g.,
long-finned pilot whale). Vineyard Wind used maximum monthly density
from June to December for density-based calculations.
The density models (Roberts et al., 2023) provided density for
pilot whales and seals as guilds. Based upon habitat and ranging
patterns (Hayes et al., 2023), all pilot whales occurring in the LIA
are expected to be long-finned pilot whales. Therefore, all pilot whale
density estimates are assumed to represent long-finned pilot whales.
Seal guild density was divided into species-specific densities based
upon the proportions of each species observed by PSOs during 2016 and
2018-2021 site characterizations surveys within SNE (ESS Group, 2016;
Vineyard Wind 2018, 2019, 2023a-f). Of the 181 seals identified to
species and sighted within the WDA, 162 were gray seals and 19 were
harbor seals. The equation below shows how the proportion of each seal
species sighted was calculated to compute density for seals.
Pseal species = Nseal species/
Numbertotal seals identified,
where P represents density and N represents number of seals.
These calculations resulted in proportions of 0.895 for gray seals
and 0.105 for harbor seals. The proportion for each species was then
multiplied by the maximum monthly density for the seal guild (table 8)
to determine the species-specific densities used in take calculations.
The density models (Roberts et al., 2023) also do not distinguish
between bottlenose dolphin stocks and only provide densities for
bottlenose dolphins as a species. However, as described above, based
upon ranging patterns (Hayes et al., 2023), only the Western North
Atlantic offshore stock of bottlenose dolphins is expected to occur in
the LIA. Therefore, it is expected that the bottlenose dolphin density
estimate is entirely representative of this stock. Maximum mean monthly
density estimates and month of the maximum estimate is provided in
table 8 below.
Table 8--Maximum Mean Monthly Marine Mammal Density Estimates (Animals per km\2\) Considering a 10-km Buffer
Around the Limited Installation Area
----------------------------------------------------------------------------------------------------------------
Species Maximum mean density Maximum density month
----------------------------------------------------------------------------------------------------------------
NARW *.................................... 0.0043 December.
Fin whale *............................... 0.0036 July.
Humpback whale............................ 0.0022 June.
Minke whale............................... 0.018 June.
Sei whale *............................... 0.0008 November.
Sperm whale *............................. 0.0008 September.
Atlantic white-sided dolphin.............. 0.0204 June.
Bottlenose dolphin \a\.................... 0.008 August.
Common dolphin............................ 0.1467 September.
Long-finned pilot whale \b\............... 0.001 N/A.
[[Page 31041]]
Risso's dolphin........................... 0.0013 December.
Harbor porpoise........................... 0.0713 December.
Seals (gray and harbor) \c\............... 0.1745 May.
----------------------------------------------------------------------------------------------------------------
Note: * denotes species listed under the ESA.
\a\ Density estimate represents the Northwestern Atlantic offshore stock of bottlenose dolphins.
\b\ Only annual densities were available for the pilot whale guild.
\c\ Gray and harbor seals represented as a guild.
For some species, PSO survey and construction data for SNE (ESS
Group, 2016; Vineyard Wind, 2018, 2019, 2023a-f) and mean group size
data compiled from the Atlantic Marine Assessment Program for Protected
Species (AMAPPS) (Palka et al., 2017, 2021) indicate that the density-
based exposure estimates may be insufficient to account for the number
of individuals of a species that may be encountered during the planned
activities. Hence, consideration of local PSO and AMAPPS data is
required to ensure the potential for take is adequately assessed.
In cases where the density-based Level B harassment exposure
estimate for a species was less than the mean group size-based exposure
estimate, the take request was increased to the mean group size (in
some cases multiple groups were assumed) and rounded to the nearest
integer (table 9). For all cetaceans, with the exception of NARWs,
Vineyard Wind used the mean of the spring, summer, and fall AMAPPS
group sizes for each species for the RI/MA WEA as shown in tables 2-2,
2-3, and 2-4 in Palka et al. (2021) appendix III. These seasons were
selected as they would represent the time period in which pile driving
activities would take place. Mean group sizes for cetacean species
derived from RI/WEA AMAPPS data is shown below in table 9. However,
NARW seasonal group sizes for the RI/MA WEA were not available through
the AMAPPS dataset (Palka et al., 2021). Vineyard Wind calculated mean
group size for NARWs using data from the northeast (NE) shipboard
surveys as provided in table 6-5 of Palka et al. (2021). Vineyard Wind
calculated mean group size by dividing the number of individual right
whales sighted (4) by the number of right whale groups (2) (Palka et
al., 2021). The NE shipboard surveys were conducted during summer (June
1 through August 31) and fall (September 1 through November 30) seasons
(Palka et al., 2021).
For seals, mean group size data was also not available for the RI/
MA WEA through AMAPPS (Palka et al., 2021). Vineyard Wind used 2010-
2013 AMAPPS NE shipboard and aerial survey at-sea seal sightings for
gray and harbor seals, as well as unidentified seal sightings from
spring, summer, and fall to calculate mean group size for gray and
harbor seals (table 19-1, Palka et al., 2017). To calculate mean group
size for seals, Vineyard Wind divided the total number of animals
sighted by the total number of sightings. As the majority of the
sightings were not identified to species, Vineyard Wind calculated a
single group size for all seal species (table 9).
Additional detail regarding the density and occurrence as well as
the assumptions and methodology used to estimate take is included below
and in section 6.2 of the ITA application. Mean group sizes used in
take estimates, where applicable, for all activities are provided in
table 9.
Table 9--Mean Marine Mammal Group Sizes Used in Take Estimate
Calculations
------------------------------------------------------------------------
Species Mean group size Source
------------------------------------------------------------------------
NARW *.......................... 2 Table 6-5 of Palka
et al., 2021.
Fin whale *..................... 1.2 Palka et al., 2021.
Humpback whale.................. 1.2 Palka et al., 2021.
Minke whale..................... 1.4 Palka et al., 2021.
Sei whale *..................... 1 Palka et al., 2021.
Sperm whale *................... 2 Palka et al., 2021.
Atlantic white-sided dolphin.... 21.7 Palka et al., 2021.
Bottlenose dolphin.............. 11.7 Palka et al., 2021.
Common dolphin.................. 30.8 Palka et al., 2021.
Long-finned pilot whale......... 12.3 Palka et al., 2021.
Risso's dolphin................. 1.8 Palka et al., 2021.
Harbor porpoise................. 2.9 Palka et al., 2021.
Seals (gray and harbor)......... 1.4 Table 19-1 of Palka
et al., 2017.
------------------------------------------------------------------------
Note: * denotes species listed under the ESA.
Vineyard Wind also looked at PSO survey data (June through October
2023) in the LIA collected during Vineyard Wind I construction
activities and calculated a daily sighting rate for species to compare
with density-based take estimates and average group size estimates from
AMAPPS (table 9). The number of animals of each species sighted from
all survey vessels with active PSOs was divided by the sum of all PSO
monitoring days (77 days) to calculate the mean number of animals of
each species sighted (see table 11 in the ITA application). However,
for each species, the PSO data-based exposure estimate was less than
the density-based exposure estimate (see table 14 in the ITA
application) and, therefore, density-based exposure estimates were not
adjusted according to PSO data-based exposure estimates.
Here we present the amount of take requested by Vineyard Wind and
proposed to be authorized. To estimate take, Vineyard Wind use the pile
installation construction schedule
[[Page 31042]]
shown in table 6, assuming 15 total days of monopile installation. NMFS
has reviewed these methods to estimate take and agrees with this
approach. The proposed take numbers in table 11, appropriately consider
SFV measurements collected in 2023 and represent the maximum amount of
take that is reasonably expected to occur.
Table 10--Modeled Level A Harassment and Level B Harassment Acoustic
Exposure Estimates
------------------------------------------------------------------------
Density-based exposure estimate
Species -------------------------------------------
Level A harassment Level B harassment
------------------------------------------------------------------------
NARW * \a\.................. 0.503 6.6
Fin whale *................. 0.598 5.5
Humpback whale.............. 1.11 3.4
Minke whale................. 0.372 27.7
Sei whale *................. 0.144 1.2
Sperm whale *............... 0 1.2
Atlantic white-sided dolphin 0 31.4
Bottlenose dolphin.......... 0 12.3
Common dolphin.............. 0 226
Long-finned pilot whale..... 0 1.5
Risso's dolphin............. 0 2
Harbor porpoise............. 2.758 109.8
Gray Seal................... 0 240.8
Harbor seal................. 0.028 28.2
------------------------------------------------------------------------
Note: * denotes species listed under the ESA.
\a\ Although modeling shows a very low but non-zero exposure estimate
for take by Level A harassment, mitigation measures will be applied to
ensure there is no take by Level A harassment of this species.
Table 11--Proposed Authorized Takes
[by Level A harassment and Level B harassment]
----------------------------------------------------------------------------------------------------------------
Proposed take Proposed take Total Percent of
Species NMFS stock by Level A by Level B proposed stock
abundance harassment harassment take abundance
----------------------------------------------------------------------------------------------------------------
NARW * \a\............................... 338 0 7 7 2.07
Fin whale *.............................. 6,802 1 6 7 0.1
Humpback whale........................... 1,396 2 4 6 0.43
Minke whale.............................. 21,968 1 28 29 0.13
Sei whale *.............................. 6,292 1 2 3 0.05
Sperm whale *............................ 4,349 0 2 2 0.05
Atlantic white-sided dolphin............. 93,233 0 32 32 0.03
Bottlenose dolphin....................... 62,851 0 13 13 0.02
Common dolphin \b\ \c\................... 172,974 0 462 462 0.27
Long-finned pilot whale \b\.............. 39,215 0 13 13 0.03
Risso's dolphin.......................... 35,215 0 2 2 0.001
Harbor porpoise.......................... 95,543 3 110 113 0.19
Gray Seal................................ 27,300 0 241 241 0.88
Harbor seal.............................. 61,336 1 29 30 0.05
----------------------------------------------------------------------------------------------------------------
Note: * denotes species listed under the ESA.
\a\ Although modeling shows a very low but non-zero exposure estimate for take by Level A harassment, mitigation
measures will be applied to ensure there is no take by Level A harassment of this species.
\b\ Proposed take by Level B harassment adjusted according to mean group size.
\c\ Proposed take by Level B harassment is based upon the assumption that one group of common dolphins (30.8
dolphins; see table 9) would be encountered per each of the 15 days of pile driving.
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 the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (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 the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
effect the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers 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
[[Page 31043]]
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost and impact on
operations.
The mitigation strategies described below are consistent with those
required and successfully implemented under previous incidental take
authorizations issued in association with in-water construction
activities (e.g., soft-start, establishing shutdown zones). Additional
measures have also been incorporated to account for the fact that the
proposed construction activities would occur offshore. In addition,
several measures proposed for this IHA (i.e., seasonal restrictions,
vessel strike avoidance, and clearance and shutdown zones) are more
rigorous than measures previously incorporated into the 2023 IHA.
Generally speaking, the mitigation measures considered and proposed
to be required here fall into three categories: (1) temporal (seasonal
and daily) work restrictions, (2) real-time measures (shutdown,
clearance, and vessel strike avoidance), and (3) noise attenuation/
reduction measures. Seasonal work restrictions are designed to avoid or
minimize operations when marine mammals are concentrated or engaged in
behaviors that make them more susceptible or make impacts more likely,
in order to reduce both the number and severity of potential takes, and
are effective in reducing both chronic (longer-term) and acute effects.
Real-time measures, such as implementation of shutdown and clearance
zones, as well as vessel strike avoidance measures, are intended to
reduce the probability or severity of harassment by taking steps in
real time once a higher-risk scenario is identified (e.g., once animals
are detected within an impact zone). Noise attenuation measures, such
as bubble curtains, are intended to reduce the noise at the source,
which reduces both acute impacts, as well as the contribution to
aggregate and cumulative noise that may result in longer-term chronic
impacts. Below, we also describe the required training, coordination,
and vessel strike avoidance measures that apply to foundation
installation and vessel use.
Training and Coordination
NMFS requires all Vineyard Wind's employees and contractors
conducting activities on the water, including, but not limited to, all
vessel captains and crew, to be trained in marine mammal detection and
identification, communication protocols, and all required measures to
minimize impacts on marine mammals and support Vineyard Wind's
compliance with the IHA, if issued. Additionally, all relevant
personnel and the marine mammal species monitoring team(s) are required
to participate in joint, onboard briefings prior to the beginning of
project activities. The briefing must be repeated whenever new relevant
personnel (e.g., new PSOs, construction contractors, relevant crew)
join the project before work commences. During this training, Vineyard
Wind is required to instruct all project personnel regarding the
authority of the marine mammal monitoring team(s). For example, pile
driving personnel are required to immediately comply with any call for
a delay or shut down by the Lead PSO. Any disagreement between the Lead
PSO and the project personnel must only be discussed after delay or
shutdown has occurred. In particular, all captains and vessel crew must
be trained in marine mammal detection and vessel strike avoidance
measures to ensure marine mammals are not struck by any project or
project-related vessel.
Prior to the start of in-water construction activities, Vineyard
Wind would conduct training for construction and vessel personnel and
the marine mammal monitoring team (PSO and PAM operators) to explain
responsibilities, communication procedures, marine mammal detection and
identification, mitigation, monitoring, and reporting requirements,
safety and operational procedures, and authorities of the marine mammal
monitoring team(s). A description of the training program must be
provided to NMFS at least 60 days prior to the initial training before
in-water activities begin. Vineyard Wind would provide confirmation of
all required training documented on a training course log sheet and
reported to NMFS OPR prior to initiating project activities.
NARW Awareness Monitoring
Vineyard Wind would be required to use available sources of
information on NARW presence, including daily monitoring of the Right
Whale Sightings Advisory System, U.S. Coast Guard very high-frequency
(VHF) Channel 16, WhaleAlert, and the PAM system throughout each day to
receive notifications of any Slow Zones (i.e., Dynamic management areas
(DMAs) and/or acoustically-triggered slow zones) to provide situational
awareness for vessel operators, PSOs, and PAM operators. The marine
mammal monitoring team must monitor these systems at least every 4
hours. Maintaining daily awareness and coordination affords increased
protection of NARWs by understanding NARW presence in the area through
ongoing visual and passive acoustic monitoring efforts and
opportunities (outside of Vineyard Wind's efforts), and allows for
planning of construction activities, when practicable, to minimize
potential impacts on NARWs.
Vessel Strike Avoidance Measures
This proposed IHA contains numerous vessel strike avoidance
measures that reduce the risk that a vessel and marine mammal could
collide. While the likelihood of a vessel strike is generally low, they
are one of the most common ways that marine mammals are seriously
injured or killed by human activities. Therefore, enhanced mitigation
and monitoring measures are required to avoid vessel strikes, to the
extent practicable. While many of these measures are proactive,
intending to avoid the heavy use of vessels during times when marine
mammals of particular concern may be in the area, several are reactive
and occur when a project personnel sights a marine mammal. Vineyard
Wind would be required to comply with these measures except under
circumstances when doing so would create an imminent and serious threat
to a person or vessel or to the extent that a vessel is unable to
maneuver and, because of the inability to maneuver, the vessel cannot
comply.
While underway, Vineyard Wind's personnel would be required to
monitor for and maintain a minimum separation distance from marine
mammals and operate vessels in a manner that reduces the potential for
vessel strike. Regardless of the vessel's size or speed, all vessel
operators, crews, and dedicated visual observers (i.e., PSO or trained
crew member) must maintain a vigilant watch for all marine mammals and
slow down, stop their vessel, or alter course (as appropriate) to avoid
striking any marine mammal. The dedicated visual observer, required on
all transiting vessels and equipped with suitable monitoring technology
(e.g., binoculars, night vision devices), must be located at an
appropriate vantage point for ensuring vessels are maintaining required
vessel separation distances from marine mammals (e.g., 500 m from
NARWs).
All of the project-related vessels would be required to comply with
existing NMFS vessel speed restrictions for NARWs, and additional speed
and approach restrictions measures within this IHA. All vessels must
reduce speed to 10 kn or less when traveling in a DMA, Slow Zone or
when a NARW is observed or acoustically detected. Reducing vessel speed
is one of the most effective, feasible options available
[[Page 31044]]
to reduce the likelihood of and effects from a vessel strike. Numerous
studies have indicated that slowing the speed of vessels reduces the
risk of lethal vessel collisions, particularly in areas where right
whales are abundant and vessel traffic is common and otherwise
traveling at high speeds (Vanderlaan and Taggart, 2007; Conn and
Silber, 2013; Van der Hoop et al., 2014; Martin et al., 2015; Crum et
al., 2019).
When NMFS vessel speed restrictions are not in effect and a vessel
is traveling at greater than 10 kn (18.5 km/hr), in addition to the
required dedicated visual observer, Vineyard Wind would be required to
monitor the crew transfer vessel transit corridor (the path crew
transfer vessels take from port to any work area) in real-time with PAM
prior to and during transits.
All project vessels, regardless of size, must maintain the
following minimum separation zones: 500 m from NARWs; 100 m from sperm
whales and non-NARW baleen whales; and 50 m from all delphinid
cetaceans and pinnipeds (an exception is made for those species that
approach the vessel such as bow-riding dolphins) (table 12). All
reasonable steps must be taken to not violate minimum separation
distances. If any of these species are sighted within their respective
minimum separation zone, the underway vessel must turn away from the
animal and shift its engine to neutral (if safe to do so) and the
engines must not be engaged until the animal(s) have been observed to
be outside of the vessel's path and beyond the respective minimum
separation zone. If a NARW is observed at any distance by any project
personnel or acoustically detected, project vessels must reduce speeds
to 10 kn and turn away from the animal. Additionally, in the event that
any project-related vessel, regardless of size, observes any large
whale (other than a NARW) within 500 m of an underway vessel, the
vessel is required to immediately reduce speeds to 10 kn or less and
turn away from the animal.
Table 12--Vessel Strike Avoidance Separation Zones
------------------------------------------------------------------------
Vessel separation zone
Marine mammal species (m)
------------------------------------------------------------------------
NARW........................................... 500
Other ESA-listed species and non-NARW large 100
whales........................................
Other marine mammals \a\....................... 50
------------------------------------------------------------------------
\a\ With the exception of seals and delphinid(s) from the genera
Delphinus, Lagenorhynchus, Stenella, or Tursiops, as described below.
Any marine mammal observed by project personnel must be immediately
communicated to any on-duty PSOs, PAM operator(s), and all vessel
captains. Any NARW or large whale observation or acoustic detection by
PSOs or PAM operators must be conveyed to all vessel captains. All
vessels would be equipped with an AIS and Vineyard Wind must report all
Maritime Mobile Service Identity (MMSI) numbers to NMFS OPR prior to
initiating in-water activities. Vineyard Wind has submitted an updated
NMFS-approved NARW Vessel Strike Avoidance Plan, which NMFS is
reviewing for alignment with the measures proposed herein.
Given the extensive vessel strike avoidance measures coupled with
the limited amount of work associated with the project, NMFS has
determined that Vineyard Wind's compliance with these proposed measures
would reduce the likelihood of vessel strike to discountable levels.
Seasonal and Daily Restrictions
Temporal restrictions in places where marine mammals are
concentrated, engaged in biologically important behaviors, and/or
present in sensitive life stages are effective measures for reducing
the magnitude and severity of human impacts. The temporal restrictions
proposed here are built around NARW protection. Based upon the best
scientific information available (Roberts et al., 2023), the highest
densities of NARWs in the specified geographic region are expected
during the months of January through May, with an increase in density
starting in December. However, NARWs may be present in the specified
geographic region throughout the year.
NMFS is proposing to require seasonal work restrictions to minimize
risk of noise exposure to the NARWs incidental to pile driving
activities to the extent practicable. These seasonal work restrictions
are expected to reduce the number of takes of NARWs and further reduce
vessel strike risk. These seasonal restrictions also afford protection
to other marine mammals that are known to use the LIA with greater
frequency during winter months, including other baleen whales. As
described previously, no impact pile driving activities may occur
January 1 through May 31, and pile driving in December must be avoided
to the maximum extent practicable and only if enhanced monitoring is
undertaken and NMFS approves.
Vineyard Wind proposed to install no more than one pile per day and
only initiate impact pile driving during daylight hours. Vineyard Wind
would not be able to initiate pile driving later than 1.5 hours after
civil sunset or continue pile driving after or 1 hour before civil
sunrise. However, if Vineyard Wind determines that they must initiate
pile driving after the aforementioned time frame, they must submit a
sufficient nighttime pile driving plan for NMFS review and approval to
do so. A sufficient nighttime pile driving plan would demonstrate that
proposed detection systems would be capable of detecting marine
mammals, particularly large whales, at distances necessary to ensure
mitigation measures are effective.
Noise Attenuation Systems
Vineyard Wind would be required to employ noise abatement systems
(NAS), also known as noise attenuation systems, during all foundation
installation activities to reduce the sound pressure levels that are
transmitted through the water in an effort to reduce acoustic ranges to
the Level A harassment and Level B harassment acoustic thresholds and
minimize, to the extent practicable, any acoustic impacts resulting
from these activities. Vineyard Wind proposes and NMFS is proposing to
require Vineyard Wind to use a double bubble curtain (DBBC) and Hydro
Sound damper (HSD) in addition to an enhanced big bubble curtain (BBC)
maintenance schedule. The refined NAS design (DBBC + HSD + enhanced
bubble curtain (BC) maintenance schedule) used during the 2023
construction activities would be used on the 15 remaining piles to
minimize noise levels. A single bubble curtain, alone or in combination
with another NAS device, may not be used for pile driving as received
SFV data reveals this approach is unlikely to attenuate sound
sufficiently to be
[[Page 31045]]
consistent with the target sound reduction of 6 dB, in which the
expected ranges to the Level A harassment and Level B harassment
isopleths are based upon.
Two categories of NAS exist: primary and secondary. A primary NAS
would be used to reduce the level of noise produced by foundation
installation activities at the source, typically through adjustments to
the equipment (e.g., hammer strike parameters). Primary NAS are still
evolving and will be considered for use during mitigation efforts when
the NAS has been demonstrated as effective in commercial projects.
However, as primary NAS are not fully effective at eliminating noise, a
secondary NAS would be employed. The secondary NAS is a device or group
of devices that would reduce noise as it is transmitted through the
water away from the pile, typically through a physical barrier that
would reflect or absorb sound waves and therefore reduce the distance
the higher energy sound propagates through the water column. Together,
these systems must reduce noise levels to those not exceeding expected
ranges to Level A harassment and Level B harassment isopleths
corresponding to those modeled assuming 6-dB sound attenuation, pending
results of SFV (see Sound Field Verification section below).
Noise abatement systems, such as bubble curtains, are used to
decrease the sound levels radiated from a source. Bubbles create a
local impedance change that acts as a barrier to sound transmission.
The size of the bubbles determines their effective frequency band, with
larger bubbles needed for lower frequencies. There are a variety of
bubble curtain systems, confined or unconfined bubbles, and some with
encapsulated bubbles or panels. Attenuation levels also vary by type of
system, frequency band, and location. Small bubble curtains have been
measured to reduce sound levels, but effective attenuation is highly
dependent on depth of water, current, and configuration and operation
of the curtain (Austin et al., 2016; Koschinski and L[uuml]demann,
2013). Bubble curtains vary in terms of the sizes of the bubbles; those
with larger bubbles tend to perform a bit better and more reliably,
particularly when deployed with two separate rings (Bellmann, 2014;
Koschinski and L[uuml]demann, 2013; Nehls et al., 2016). Encapsulated
bubble systems (i.e., HSDs) can be effective within their targeted
frequency ranges (e.g., 100-800 Hz) and when used in conjunction with a
bubble curtain appear to create the greatest attenuation. The
literature presents a wide array of observed attenuation results for
bubble curtains. The variability in attenuation levels is the result of
variation in design as well as differences in site conditions and
difficulty in properly installing and operating in-water attenuation
devices.
For example, D[auml]hne et al. (2017) found that single bubble
curtains that reduce sound levels by 7 to 10 dB reduced the overall
sound level by approximately 12 dB when combined as a double bubble
curtain for 6-m steel monopiles in the North Sea. During installation
of monopiles (consisting of approximately 8-m in diameter) for more
than 150 WTGs in comparable water depths (>25 m) and conditions in
Europe indicate that attenuation of 10 dB is readily achieved
(Bellmann, 2019; Bellmann et al., 2020) using single BBCs for noise
attenuation. When a DBBC is used (noting a single BC is not allowed),
Vineyard Wind would be required to maintain numerous operational
performance standards, including the enhanced BBC maintenance protocol
(Vineyard Wind Enhanced BBC Technical Memo, 2023). These standards are
defined in the proposed IHA and include, but are not limited to, a
requirement that construction contractors train personnel in the
proposed balancing of airflow to the bubble ring; and a requirement
that Vineyard Wind submit a performance test and maintenance report to
NMFS within 72 hours following the performance test. Corrections to the
attenuation device to meet regulatory requirements must occur prior to
use during foundation installation activities. In addition, a full
maintenance check (e.g., manually clearing holes) must occur prior to
each pile being installed.
The HSD system Vineyard Wind proposes to use would be employed, in
coordination with the DBBC, as a near-field attenuation device close to
the monopiles (K[uuml]sel et al., 2024). Vineyard Wind has also
proposed to follow a DBBC enhanced maintenance protocol, which was used
during the 2023 Vineyard Wind pile installation activities. The DBBC
enhanced maintenance protocol includes an adjustment from typical
bubble curtain operations to drill hoses after every deployment to
maximize performance in siltier sediments which are present in the
Lease Area. The DBBC enhanced maintenance protocol also includes DBBC
hose inspection and clearance, pressure testing of DBBC hoses, visual
inspection of DBBC performance, and minimizing disturbance of the DBBC
hoses on the seafloor.
Should SFV identify that distances to NMFS harassment isopleths are
louder than expected, Vineyard Wind would be required to adjust the
NAS, or conduct other measures to reduce noise levels, such that
distances to thresholds are not exceeded.
Clearance and Shutdown Zones
NMFS is proposing to require the establishment of both clearance
and shutdown zones during impact pile driving. The purpose of
``clearance'' of a particular zone is to minimize potential instances
of auditory injury and more severe behavioral disturbances by delaying
the commencement of an activity if marine mammals are near the
activity. The purpose of a ``shutdown'' is to prevent a specific acute
impact, such as auditory injury or severe behavioral disturbance of
sensitive species, by halting the activity. Due to the increased
density of NARWs during the months of November and December, more
stringent clearance and shutdown mitigation measures are proposed for
these months.
All relevant clearance and shutdown zones during project activities
would be monitored by NMFS-approved PSOs and PAM operators. PAM would
be conducted at least 24 hours in advance of any pile driving
activities. At least one PAM operator would review data from at least
24 hours prior to foundation installation (to increase situational
awareness) and actively monitor hydrophones for 60 minutes prior to
commencement of these activities. Any sighting or acoustic detection of
a NARW would trigger a delay to commencing pile driving and shutdown.
Prior to the start of pile driving activities, Vineyard Wind would
be required to ensure designated areas (i.e., clearance zones, table
13) are clear of marine mammals before commencing activities to
minimize the potential for and degree of harassment. Three on-duty PSOs
would monitor from the pile driving support vessel and two PSO support
vessels, each with three PSOs on board, before (60 minutes), during,
and after (30 minutes) all pile driving. PSOs must visually monitor
clearance zones for marine mammals for a minimum of 60 minutes, where
the zone must be confirmed free of marine mammals at least 30 minutes
directly prior to commencing these activities. The minimum visibility
zone, defined as the area over which PSOs must be able to visually
detect marine mammals, would extend 4,000 m for monopile installation
from the pile being driven (table 13), and must be visible for 60
minutes. The minimum visibility zone corresponds to the modeled Level A
harassment distance for low-frequency cetaceans plus twenty percent,
and
[[Page 31046]]
rounded up to the nearest 0.5 km. The minimum visibility zone must be
visually cleared of marine mammals. If this zone is obscured to the
degree that effective monitoring cannot occur, pile driving must be
delayed. Minimum visibility zone and clearance zones are defined and
provided in table 13 for all species.
From December 1 to 31, a vessel-based survey would be used to
confirm the clearance zone (10 km PAM clearance zone (6.2 mi); table
13) is clear of NARWs prior to pile driving. The survey would be
supported by a team of nine PSOs coordinating visual monitoring across
two PSO support vessels and the pile driving platform. The two PSO
support vessels, each with three active on-duty PSOs, would be
positioned at the same distance on either side of the pile driving
vessel. Each PSO support vessel would transit along a steady course
along parallel track lines in opposite directions. Each transect line
would be surveyed at a similar speed, not to exceed 10 kn, and would
last for approximately 30 minutes to 1 hour. If a NARW is sighted at
any distance during the vessel-based survey, pile driving would be
delayed until the following day unless an additional vessel-based
survey with additional transects are conducted to determine the
clearance zone is clear of NARWs. Further details on PSO support vessel
monitoring efforts are described in the Vineyard Wind application
section 11, table 17.
Once pile driving activity begins, any marine mammal entering their
respective shutdown zone would trigger the activity to cease. In the
case of pile driving, the shutdown requirement may be waived if is not
practicable due to imminent risk of injury or loss of life to an
individual or risk of damage to a vessel that creates risk of injury or
loss of life for individuals, or if the lead engineer determines there
is pile refusal or pile instability.
In situations when shutdown is called for, but Vineyard Wind
determines shutdown is not practicable due to aforementioned emergency
reasons, reduced hammer energy must be implemented when the lead
engineer determines it is practicable. Specifically, pile refusal or
pile instability could result in the inability to shut down pile
driving immediately. Pile refusal occurs when the pile driving sensors
indicate the pile is approaching refusal, and a shut-down would lead to
a stuck pile which then poses an imminent risk of injury or loss of
life to an individual, or risk of damage to a vessel that creates risk
for individuals. Pile instability occurs when the pile is unstable and
unable to stay standing if the piling vessel were to ``let go.'' During
these periods of instability, the lead engineer may determine a shut-
down is not feasible because the shut-down combined with impending
weather conditions may require the piling vessel to ``let go'' which
then poses an imminent risk of injury or loss of life to an individual,
or risk of damage to a vessel that creates risk for individuals.
Vineyard Wind must document and report to NMFS all cases where the
emergency exemption is taken.
After shutdown, impact pile driving may be reinitiated once all
clearance zones are clear of marine mammals for the minimum species-
specific periods, or, if required to maintain pile stability, impact
pile driving may be reinitiated but must be used to maintain stability.
From June 1 to October 31, if pile driving has been shut down due to
the presence of a NARW, pile driving must not restart until the NARW
has not been visually or acoustically detected for 30 minutes. Upon re-
starting pile driving, soft-start protocols must be followed if pile
driving has ceased for 30 minutes or longer. From November 1 to
December 31, if pile driving has been shut down or delayed due to the
presence of three or more NARWs, pile driving will be postponed until
the next day. Shutdown zones vary by species and are shown in table 13
below.
Table 13--Minimum Visibility, Clearance, Shutdown, and Level B Harassment Zones, in Meters (m), During Impact
Pile Driving
----------------------------------------------------------------------------------------------------------------
Other Pilot whales,
mysticetes/ harbor porpoises, Pinnipeds (m)
Monitoring zones NARWs \a\ sperm whales and delphinids (m) \b\
(m) \b\ \b\
----------------------------------------------------------------------------------------------------------------
Minimum Visibility Zone \c\......... 4,000
---------------------------------------------------------------------------
Visual Clearance Zone............... Any distance from PSOs 500 160 160
PAM Clearance Zone.................. 10,000................ 500 160 160
Visual Shutdown Zone................ Any distance.......... 500 160 160
PAM Monitoring Zone \d\............. 10,000................ 500 160 160
---------------------------------------------------------------------------
Distance to Level B Harassment 5,720
Threshold.
----------------------------------------------------------------------------------------------------------------
\a\ From December 1 to December 31, vessel based surveys using two PSO support vessels would confirm that the 10-
km (6.2-mi) PAM clearance zone is clear of NARWs. If three or more NARWs are sighted in November or December,
pile driving will be delayed for 24 hours.
\b\ Pile driving may commence when either the marine mammal has voluntarily left the respective clearance zone
and has been visually confirmed beyond that clearance zone, or when 30 minutes (NARWs (June-October), other
non-NARW mysticetes, sperm whales, pilot whales, Risso's dolphins) or 15 minutes (all other delphinids and
pinnipeds)have elapsed without re-detection.
\c\ Minimum visibility zone is the minimum distance that must be visible prior to initiating pile driving, as
determined by the lead PSO. The minimum visibility zone corresponds to the Level A harassment distance for low-
frequency cetaceans plus twenty percent, and rounded up to the nearest 0.5 km
\d\ The PAM system must be capable of detecting NARWs at 10 km during pile driving. The system should also be
designed to detect other marine mammals to the maximum extent practicable; however, it is not required these
other species be detected out to 10 km given higher frequency calls and echolocation clicks are not typically
detectable at large distances.
For any other in-water construction heavy machinery activities
(e.g., trenching, cable laying, etc.), if a marine mammal is on a path
towards or comes within 10 m (32.8 ft) of equipment, Vineyard Wind
would be required to delay or cease operations until the marine mammal
has moved more than 10 m on a path away from the activity to avoid
direct interaction with equipment.
Soft-start
The use of a soft-start procedure is believed to provide additional
protection to marine mammals by warning them or providing them with a
chance to leave the area prior to the
[[Page 31047]]
hammer operating at full capacity. Soft-start typically involves
initiating hammer operation at a reduced energy level (relative to full
operating capacity) followed by a waiting period. Vineyard Wind would
be required to utilize a soft-start protocol for impact pile driving of
monopiles by performing four to six single hammer strikes at less than
40 percent of the maximum hammer energy followed by at least a 1-minute
delay before the subsequent hammer strikes. This process shall be
conducted at least tjree times (e.g., four to six single strikes,
delay, four to six single strikes, delay, four to six single strikes,
delay) for a minimum of 20 minutes. NMFS notes that it is difficult to
specify a reduction in energy for any given hammer because of variation
across drivers and installation conditions. Vineyard Wind will reduce
energy based on consideration of site-specific soil properties and
other relevant operational considerations.
Soft start would be required at the beginning of each day's
activity and at any time following a cessation of activity of 30
minutes or longer. Prior to soft-start, the operator must receive
confirmation from the PSO that the clearance zone is clear of any
marine mammals.
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 of
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. NMFS' MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorization 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 while
conducting the activities. 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 activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
Mitigation and monitoring effectiveness.
Separately, monitoring is also regularly used to support mitigation
implementation, which is referred to as mitigation monitoring, and
monitoring plans typically include measures that both support
mitigation implementation and increase our understanding of the impacts
of the activity on marine mammals.
Protected Species Observer and PAM Operator Requirements
PSOs are trained professionals who are tasked with visual
monitoring for marine mammals during pile driving activities. The
primary purpose of a PSO is to carry out the monitoring, collect data,
and, when appropriate, call for the implementation of mitigation
measures. Visual monitoring by NMFS-approved PSOs would be conducted at
a minimum of 60 minutes before, during, and 30 minutes after all
proposed impact pile driving activities. In addition to visual
observations, NMFS would require Vineyard Wind to conduct PAM using
NMFS-approved PAM operators during impact pile driving and vessel
transit. PAM would also be conducted for 24 hours in advance and during
impact pile driving activities. Visual observations and acoustic
detections would be used to support the mitigation measures (e.g.,
clearance zones). To increase understanding of the impacts of the
activity on marine mammals, PSOs must record all incidents of marine
mammal occurrence at any distance from the piling locations. PSOs would
document all behaviors and behavioral changes, in concert with distance
from an acoustic source.
NMFS proposes to require PAM conducted by NMFS-approved PAM
operators, following a standardized measurement, processing methods,
reporting metrics, and metadata standards for offshore wind. PAM
alongside visual data collection is valuable to provide the most
accurate record of species presence as possible, and these two
monitoring methods are well understood to provide best results when
combined together (e.g., Barlow and Taylor, 2005; Clark et al., 2010;
Gerrodette et al., 2011; Van Parijs et al., 2021). Acoustic monitoring
(in addition to visual monitoring) increases the likelihood of
detecting marine mammals within the shutdown and clearance zones of
project activities, which when applied in combination with required
shutdowns helps to further reduce the risk of marine mammals being
exposed to sound levels that could otherwise result in acoustic injury
or more intense behavioral harassment.
The exact configuration and number of PAM systems depends on the
size of the zone(s) being monitored, the amount of noise expected in
the area, and the characteristics of the signals being monitored. More
closely spaced hydrophones would allow for more directionality, and
perhaps, range to the vocalizing marine mammals; although, this
approach would add additional costs and greater levels of complexity to
the project. Larger baleen cetacean species (i.e., mysticetes), which
produce loud and lower-frequency vocalizations, may be able to be heard
with fewer hydrophones spaced at greater distances. However, smaller
cetaceans (such as mid-frequency delphinids or odontocetes) may
necessitate more hydrophones and to be spaced closer together given the
shorter range of the shorter, mid-frequency acoustic signals (e.g.,
whistles and echolocation clicks). The configuration for collecting the
required marine mammal data will be based upon the acoustic data
acquisition methods used during the 2023 Vineyard Wind construction
campaign (K[uuml]sel et al., 2024).
NMFS does not formally administer any PSO or PAM operator training
program or endorse specific providers but would approve PSOs and PAM
[[Page 31048]]
operators that have successfully completed courses that meet the
curriculum and trainer requirements. All PSOs and PAM operators must
have successfully attained a bachelor's degree from an accredited
college or university with a major in one of the natural sciences, a
minimum of 30 semester hours or equivalent in the biological sciences,
and at least one undergraduate course in math or statistics. The
educational requirements may be waived if the PSO or PAM operator has
acquired the relevant skills through alternate experience. Requests for
such a waiver shall be submitted to NMFS and must include written
justification. Alternate experience that may be considered includes,
but is not limited to: (1) secondary education and/or experience
comparable to PSO and/or PAM operator duties; (2) previous work
experience conducting academic, commercial, or government-sponsored
marine mammal surveys; and (3) previous work experience as a PSO/PAM
operator (PSOs/PAM operators must be in good standing and demonstrate
good performance of PSO/PAM operator duties). All PSOs and PAM
operators must have successfully completed a relevant training course
within the last 5 years, including obtaining a certificate of course
completion that would be submitted to NMFS.
For prospective PSOs and PAM operators not previously approved, or
for PSOs and PAM operators whose approval is not current, NMFS must
review and approve PSO and PAM operator qualifications. Vineyard Wind
would be required to submit PSO and PAM operator resumes for approval
at least 60 days prior to PSO and PAM operator use. Resumes must
include information related to relevant education, experience, and
training, including dates, duration, location, and description of prior
PSO and/or PAM experience, and be accompanied by relevant documentation
of successful completion of necessary training. Should Vineyard Wind
require additional PSOs or PAM operators throughout the project,
Vineyard Wind must submit a subsequent list of pre-approved PSOs and
PAM operators to NMFS at least 15 days prior to planned use of that PSO
or PAM operator. PSOs and PAM operators must have previous experience
observing marine mammals and must have the ability to work with all
required and relevant software and equipment.
PAM operators are responsible for obtaining NMFS approval. To be
approved as a PAM operator, the person must meet the following
qualifications: The PAM operator must demonstrate that they have prior
experience with real-time acoustic detection systems and/or have
completed specialized training for operating PAM systems and detecting
and identifying Atlantic Ocean marine mammal sounds, in particular,
NARW sounds, humpback whale sounds, and how to deconflict them from
similar NARW sounds, and other co-occurring species' sounds in the area
including sperm whales. The PAM operator must be able to distinguish
between whether a marine mammal or other species sound is detected,
possibly detected, or not detected, and similar terminology must be
used across companies/projects. Where localization of sounds or
deriving bearings and distance are possible, the PAM operators need to
have demonstrated experience in using this technique. PAM operators
must be independent observers (i.e., not construction personnel), and
must demonstrate experience with relevant acoustic software and
equipment. PAM operators must have the qualifications and relevant
experience/training to safely deploy and retrieve equipment and program
the software, as necessary. PAM operators must be able to test software
and hardware functionality prior to operation, and PAM operators must
have evaluated their acoustic detection software using the PAM Atlantic
baleen whale annotated data set available at National Centers for
Environmental Information (NCEI) and provide evaluation/performance
metric. PAM operators must also be able to review and classify acoustic
detections in real-time (prioritizing NARWs and noting detection of
other cetaceans) during the real-time monitoring periods.
NMFS may approve PSOs and PAM operators as conditional or
unconditional. An unconditionally approved PSO or PAM operator is one
who has completed training within the last 5 years and attained the
necessary experience (i.e., demonstrate experience with monitoring for
marine mammals at clearance and shutdown zone sizes similar to those
produced during the respective activity). A conditionally approved PSO
or PAM operator may be one who has completed training in the last 5
years but has not yet attained the requisite field experience.
Conditionally approved PSOs and PAM operators would be paired with
an unconditionally approved PSO (or PAM operator, as appropriate) to
ensure that the quality of marine mammal observations and data
recording is kept consistent. Additionally, impact pile driving
activities would require PSOs and/or PAM operator monitoring to have a
lead on duty. The visual PSO field team, in conjunction with the PAM
team (i.e., marine mammal monitoring team) would have a lead member
(designated as the ``Lead PSO'' or ``Lead PAM operator'') who would be
required to meet the unconditional approval standard. Lead PSO or PAM
operators must also have a minimum of 90 days in a northwestern
Atlantic Ocean offshore environment performing the role (either visual
or acoustic), with the conclusion of the most recent relevant
experience not more than 18 months previous. A PSO may be trained and/
or experienced as both a PSO and PAM operator and may perform either
duty, pursuant to scheduling requirements (and vice versa).
PSOs must have visual acuity in both eyes (with correction of
vision being permissible) sufficient enough to discern moving targets
on the water's surface with the ability to estimate the target size and
distance (binocular use is allowable), ability to conduct field
observations and collect data according to the assigned protocols, and
the ability to communicate orally, by radio, or in-person, with project
personnel to provide real-time information on marine mammals observed
in the area. All PSOs must be trained in northwestern Atlantic Ocean
marine mammal identification and behaviors and must be able to conduct
field observations and collect data according to assigned protocols.
Additionally, PSOs must have the ability to work with all required and
relevant software and equipment necessary during observations.
Vineyard Wind must work with the selected third-party PSO and PAM
operator provider to ensure PSOs and PAM operators have all equipment
(including backup equipment) needed to adequately perform necessary
tasks. For PSOs, this includes, but is not limited to, accurate
determination of distance and bearing to observed marine mammals, and
to ensure that PSOs are capable of calibrating equipment as necessary
for accurate distance estimates and species identification. PSO
equipment, at a minimum, shall include:
At least one thermal (infrared) imaging device suited for
the marine environment;
Reticle binoculars (e.g., 7 x 50) of appropriate quality
(at least one per PSO, plus backups);
Global positioning units (GPS) (at least one plus
backups);
Digital cameras with a telephoto lens that is at least 300
mm or equivalent on a full-frame single lens reflex (SLR) (at least one
plus backups).
[[Page 31049]]
The camera or lens should also have an image stabilization system;
Equipment necessary for accurate measurement of distances
to marine mammal;
Compasses (at least one plus backups);
Means of communication among vessel crew and PSOs; and,
Any other tools deemed necessary to adequately and
effectively perform PSO tasks.
At least two PSOs on the pile driving vessel must be equipped with
functional Big Eye binoculars (e.g., 25 x 150; 2.7 view angle;
individual ocular focus; height control), Big Eye binocular would be
pedestal mounted on the deck at the best vantage point that provides
for optimal sea surface observation and PSO safety. PAM operators must
have the appropriate equipment (i.e., a computer station equipped with
a data collection software system available wherever they are
stationed) and use a NMFS-approved PAM system to conduct monitoring.
The equipment specified above may be provided by an individual PSO, the
third-party PSO provider, or the operator, but Vineyard Wind is
responsible for ensuring PSOs have the proper equipment required to
perform the duties specified in the IHA. Reference materials must be
available aboard all project vessels for identification of protected
species.
PSOs and PAM operators would not be permitted to exceed 4
consecutive watch hours on duty at any time, would have a 2-hour
(minimum) break between watches, and would not exceed a combined watch
schedule of more than 12 hours in a 24-hour period. If the schedule
includes PSOs and PAM operators on-duty for 2-hour shifts, a minimum 1-
hour break between watches would be allowed.
The PSOs would be responsible for monitoring the waters surrounding
the pile driving site to the farthest extent permitted by sighting
conditions, including pre-start clearance and shutdown zones, prior to,
during, and following foundation installation activities. Monitoring
must be done while free from distractions and in a consistent,
systematic, and diligent manner. If PSOs cannot visually monitor the
minimum visibility zone of 4 km (2.5 mi) prior to foundation pile
driving at all times using the required equipment, pile driving
operations must not commence or must shutdown if they are currently
active. All PSOs must be located at the best vantage point(s) on any
platform, as determined by the Lead PSO, in order to obtain 360-degree
visual coverage of the entire clearance and shutdown zones, and as much
of the Level B harassment zone as possible. PAM operators may be
located on a vessel or remotely on-shore, and must assist PSOs in
ensuring full coverage of the clearance and shutdown zones. The PAM
operator must monitor to and past the clearance zones for large whales.
All on-duty PSOs must remain in real-time contact with the on-duty
PAM operator(s). PAM operators must immediately communicate all
acoustic detections of marine mammals to PSOs, including any
determination regarding species identification, distance, and bearing
(where relevant) relative to the pile being driven and the degree of
confidence (e.g., possible, probable detection) in the determination.
The PAM operator must inform the Lead PSO(s) on duty of animal
detections approaching or within applicable ranges of interest to the
activity occurring via the data collection software system (i.e.,
Mysticetus or similar system) who must be responsible for requesting
that the designated crewmember implement the necessary mitigation
procedures (i.e., delay). All on-duty PSOs and PAM operator(s) must
remain in contact with the on-duty construction personnel responsible
for implementing mitigations (e.g., delay to pile driving) to ensure
communication on marine mammal observations can easily, quickly, and
consistently occur between all on-duty PSOs, PAM operator(s), and on-
water Project personnel. It would be the responsibility of the PSO(s)
on duty to communicate the presence of marine mammals as well as to
communicate the action(s) that are necessary to ensure mitigation and
monitoring requirements are implemented as appropriate.
At least three PSOs (on the pile driving vessel) and one PAM
operator would be on-duty and actively monitoring for marine mammals 60
minutes before, during, and 30 minutes after foundation installation in
accordance with a NMFS-approved PAM Plan. PAM would also be conducted
for at least 24 hours prior to foundation pile driving activities, and
the PAM operator must review all detections from the previous 24-hour
period prior to pile driving activities to increase situational
awareness. Throughout the year (June through December), at least three
PSOs would also be on-duty and actively monitoring from PSO support
vessels. There would be at least two PSO support vessels with on-duty
PSOs during any pile driving activities from June through December.
In addition to monitoring duties, PSOs and PAM operators are
responsible for data collection. The data collected by PSO and PAM
operators and subsequent analysis provide the necessary information to
inform an estimate of the amount of take that occurred during the
project, better understand the impacts of the project on marine
mammals, address the effectiveness of monitoring and mitigation
measures, and to adaptively manage activities and mitigation in the
future. Data reported includes information on marine mammal sightings,
activity occurring at time of sighting, monitoring conditions, and if
mitigative actions were taken.
For all visual monitoring efforts and marine mammal sightings, NMFS
proposes that the following information must be collected and reported
to NMFS OPR: the date and time that monitored activity begins or ends,
the construction activities occurring during each observation period,
the watch status (i.e., sighting made by PSO on/off effort,
opportunistic, crew, alternate vessel/platform), the PSO who sighted
the animal, the time of sighting; the weather parameters (e.g., wind
speed, percent cloud cover, visibility), the water conditions (e.g.,
Beaufort sea state, tide state, water depth); all marine mammal
sightings, regardless of distance from the construction activity;
species (or lowest possible taxonomic level possible), the pace of the
animal(s), the estimated number of animals (minimum/maximum/high/low/
best), the estimated number of animals by cohort (e.g., adults,
yearlings, juveniles, calves, group composition, etc.), the description
(i.e., as many distinguishing features as possible of each individual
seen, including length, shape, color, pattern, scars or markings, shape
and size of dorsal fin, shape of head, and blow characteristics), the
description of any marine mammal behavioral observations (e.g.,
observed behaviors such as feeding or traveling) and observed changes
in behavior, including an assessment of behavioral responses thought to
have resulted from the specific activity, the animal's closest distance
and bearing from the pile being driven and estimated time entered or
spent within the Level A harassment and/or Level B harassment zone(s),
use of noise attenuation device(s), and specific phase of activity
(e.g., soft-start for pile driving, active pile driving, etc.), the
marine mammal occurrence in Level A harassment or Level B harassment
zones, the description of any mitigation-related action implemented, or
mitigation-related actions called for but not implemented, in response
to the sighting (e.g., delay, shutdown, etc.) and time and location of
the action, and other human activity in the area.
On May 19, 2023, Vineyard Wind submitted a Pile Driving Monitoring
[[Page 31050]]
Plan for the 2023 IHA, including an Alternative Monitoring Plan, which
was approved by NMFS. The Plan included details regarding PSO and PAM
monitoring protocols and equipment proposed for use. More specifically,
the PAM portion of the plan included a description of all proposed PAM
equipment, addressed how the proposed passive acoustic monitoring must
follow standardized measurement, processing methods, reporting metrics,
and metadata standards for offshore wind as described in ``NOAA and
BOEM Minimum Recommendations for Use of Passive Acoustic Listening
Systems in Offshore Wind Energy Development Monitoring and Mitigation
Programs'' (Van Parijs et al., 2021). This plan also identified the
efficacy of the technology at detecting marine mammals in the clearance
and shutdown zones under all of the various conditions anticipated
during construction, including varying weather conditions, sea states,
and in consideration of the use of artificial lighting. Vineyard Wind
would be required to submit an updated Foundation Installation Pile
Driving Marine Mammal Monitoring Plan to NMFS Office of Protected
Resources for review, and the Plan must be approved by NMFS prior to
the start of foundation pile driving.
Sound Field Verification
Vineyard Wind would be required to conduct thorough SFV
measurements during impact pile driving activity associated with the
installation of, at minimum, the first monopile foundation and
abbreviated SFV measurements during impact installation of the
remaining monopiles to demonstrate noise levels are at or below those
measured during the 2023 Vineyard Wind construction campaign
(K[uuml]sel et al., 2024). NMFS recognizes that the SFV data collected
in 2023 occurred in warmer weather months and that water temperature
can affect the sound speed profile and, thus, propagation rates.
Therefore, if impact pile driving takes place in December, thorough SFV
measurements must be conducted during impact pile driving activity
associated with the installation of, at minimum, the first monopile
foundation. Subsequent SFV measurements would also be required should
larger piles be installed or if additional piles are driven that are
anticipated to produce louder sound fields than those previously
measured (e.g., higher hammer energy, greater number of strikes, etc.).
The measurements and reporting associated with SFV can be found in the
IHA. The proposed requirements are extensive to ensure monitoring is
conducted appropriately and the reporting frequency is such that
Vineyard Wind would be required to make adjustments quickly (e.g., add
additional sound attenuation) to ensure marine mammals are not
experiencing noise levels above those considered in this analysis. For
recommended SFV protocols for impact pile driving, please consult ISO
18406 ``Underwater acoustics--Measurement of radiated underwater sound
from percussive pile driving'' (2017). Vineyard Wind would be required
to submit an updated SFV plan to NMFS Office of Protected Resources for
review, and the Plan must be approved by NMFS prior to the start of
foundation pile driving.
For any pile driving activities, they would also be required to
submit interim and final SFV data results to NMFS and make corrections
to the noise attenuation systems in the case that any SFV measurements
demonstrate noise levels are above those expected assuming 6 dB of
attenuation. These frequent and immediate reports would allow NMFS to
better understand the sound fields to which marine mammals are being
exposed and require immediate corrective action should they be
misaligned with anticipated noise levels within our analysis.
Reporting
Prior to any construction activities occurring, Vineyard Wind would
provide a report to NMFS OPR that demonstrates that all Vineyard Wind
personnel, which includes the vessel crews, vessel captains, PSOs, and
PAM operators have completed all required training. NMFS would require
standardized and frequent reporting from Vineyard Wind during the
active period of the IHA. All data collected relating to the Project
would be recorded using industry-standard software (e.g., Mysticetus or
a similar software) installed on field laptops and/or tablets. Vineyard
Wind would be required to submit weekly, monthly, annual, and
situational reports. Vineyard Wind must review SFV results within 24
hours to determine whether measurements exceeded modeled (Level A
harassment) and expected (Level B harassment) thresholds.
Vineyard Wind must provide the initial results of the SFV
measurements to NMFS OPR in an interim report after each foundation
installation event as soon as they are available and prior to a
subsequent foundation installation, but no later than 48 hours after
each completed foundation installation event. The report must include,
at minimum: hammer energies/schedule used during pile driving,
including the total number of strikes and the maximum hammer energy,
peak sound pressure level (SPLpk), root-mean-square sound
pressure level that contains 90 percent of the acoustic energy
(SPLrms), and sound exposure level (SEL, in single strike
for pile driving, SELss,), for each hydrophone, including at
least the maximum, arithmetic mean, minimum, median (L50) and L5 (95
percent exceedance) statistics for each metric; estimated marine mammal
Level A harassment and Level B harassment isopleths, calculated using
the maximum-over-depth L5 (95 percent exceedance level, maximum of both
hydrophones) of the associated sound metric, comparison of 2023
measured results against the measured marine mammal Level A harassment
and Level B harassment acoustic isopleths, estimated transmission loss
coefficients, pile identifier name, location of the pile and each
hydrophone array in latitude/longitude, depths of each hydrophone, one-
third-octave band single strike SEL spectra, if filtering is applied,
full filter characteristics, and hydrophone specifications including
the type, model, and sensitivity. Vineyard Wind would also be required
to report any immediate observations which are suspected to have a
significant impact on the results including but not limited to:
observed noise mitigation system issues, obstructions along the
measurement transect, and technical issues with hydrophones or
recording devices. If any in-situ calibration checks for hydrophones
reveal a calibration drift greater than 0.75 dB, pistonphone
calibration checks are inconclusive, or calibration checks are
otherwise not effectively performed, Vineyard Wind would be required to
indicate full details of the calibration procedure, results, and any
associated issues in the 48-hour interim reports.
Vineyard Wind must review abbreviated SFV results for each pile
within 24 hours of completion of the foundation installation (inclusive
of pile driving and any drilling), and, assuming measured levels at 750
m did not exceed the thresholds defined during thorough SFV, does not
need to take any additional action. Results of abbreviated SFV must be
submitted with the weekly pile driving report.
The final results of SFV measurements from each foundation
installation must be submitted as soon as possible, but no later than
90 days following completion of each event's SFV measurements. The
final reports must include all details prescribed above for the interim
report as well as, at minimum, the following: the peak
[[Page 31051]]
sound pressure level (SPLpk), the root-mean-square sound
pressure level that contains 90 percent of the acoustic energy
(SPLrms), the single strike sound exposure level
(SELss), the integration time for SPLrms, the
spectrum, and the 24-hour cumulative SEL extrapolated from measurements
at all hydrophones. The final report must also include at least the
maximum, mean, minimum, median (L50) and L5 (95
percent exceedance) statistics for each metric, the SEL and SPL power
spectral density and/or one-third octave band levels (usually
calculated as decidecade band levels) at the receiver locations should
be reported, the sound levels reported must be in median, arithmetic
mean, and L5 (95 percent exceedance) (i.e., average in
linear space), and in dB, range of transmission loss coefficients, the
local environmental conditions, such as wind speed, transmission loss
data collected on-site (or the sound velocity profile), baseline pre-
and post-activity ambient sound levels (broadband and/or within
frequencies of concern), a description of depth and sediment type, as
documented in the Construction and Operation Plan (COP), at the
recording and foundation installation locations, the extents of the
measured Level A harassment and Level B harassment zone(s), hammer
energies required for pile installation and the number of strikes per
pile, the hydrophone equipment and methods (i.e., recording device,
bandwidth/sampling rate; distance from the pile where recordings were
made; the depth of recording device(s)), a description of the SFV
measurement hardware and software, including software version used,
calibration data, bandwidth capability and sensitivity of
hydrophone(s), any filters used in hardware or software, any
limitations with the equipment, and other relevant information; the
spatial configuration of the noise attenuation device(s) relative to
the pile, a description of the noise abatement system and operational
parameters (e.g., bubble flow rate, distance deployed from the pile,
etc.), and any action taken to adjust the noise abatement system. A
discussion which includes any observations which are suspected to have
a significant impact on the results including but not limited to:
observed noise mitigation system issues, obstructions along the
measurement transect, and technical issues with hydrophones or
recording devices.
If at any time during the project Vineyard Wind becomes aware of
any issue(s) that may (to any reasonable subject-matter expert,
including the persons performing the measurements and analysis) call
into question the validity of any measured Level A harassment or Level
B harassment isopleths to a significant degree, which were previously
transmitted or communicated to NMFS OPR, Vineyard Wind must inform NMFS
OPR within 1 business day of becoming aware of this issue or before the
next pile is driven, whichever comes first.
Weekly Report--During foundation installation activities, Vineyard
Wind would be required to compile and submit weekly marine mammal
monitoring reports for foundation installation pile driving to NMFS OPR
that document the daily start and stop of all pile driving activities,
the start and stop of associated observation periods by PSOs, details
on the deployment of PSOs, a record of all detections of marine mammals
(acoustic and visual), any mitigation actions (or if mitigation actions
could not be taken, provide reasons why), and details on the noise
abatement system(s) (e.g., system type, distance deployed from the
pile, bubble rate, etc.). Weekly reports will be due on Wednesday for
the previous week (Sunday to Saturday). The weekly reports are also
required to identify which turbines become operational and when (a map
must be provided).
Monthly Report--Vineyard Wind would be required to compile and
submit monthly reports to NMFS OPR that include a summary of all
information in the weekly reports, including project activities carried
out in the previous month, vessel transits (number, type of vessel, and
route), number of piles installed, all detections of marine mammals,
and any mitigative actions taken. Monthly reports would be due on the
15th of the month for the previous month. The monthly report would also
identify which turbines become operational and when (a map must be
provided).
Final Annual Reporting--Vineyard Wind would be required to submit
its draft annual report to NMFS OPR on all visual and acoustic
monitoring conducted under the IHA within 90 calendar days of the
completion of activities occurring under the IHA. A final annual report
must be prepared and submitted within 60 calendar days following
receipt of any NMFS comments on the draft report. Information contained
within this report is described at the beginning of this section.
Situational Reporting--Specific situations encountered during the
Project would require immediate reporting. For instance, if a NARW is
sighted with no visible injuries or entanglement at any time by project
PSOs or project personnel, Vineyard Wind must immediately report the
sighting to NMFS as soon as possible or within 24 hours after the
initial sighting. All NARW acoustic detections within a 24-hour period
should be collated into one spreadsheet and reported to NMFS as soon as
possible but must be reported within 24 hours. Vineyard Wind should
report sightings and acoustic detections by downloading and completing
the Real-Time NARW Reporting Template spreadsheet found here: https://www.fisheries.noaa.gov/resource/document/template-datasheet-real-time-north-atlantic-right-whale-acoustic-and-visual. Vineyard Wind would
save the completed spreadsheet as a ``.csv'' file and email it to NMFS
Northeast Fisheries Science Center Protected Resources Division (NEFSC-
PRD ([email protected]), NMFS Greater Atlantic Regional Fisheries
Office (GARFO)-PRD ([email protected]), and NMFS OPR
([email protected]). If the sighting is in the
southeast (North Carolina through Florida), sightings should be
reported via the template and to the Southeast Hotline 877-WHALE-HELP
(877-942-5343) with the observation information provided below (PAM
detections are not reported to the Hotline). If Vineyard Wind is unable
to report a sighting through the spreadsheet within 24 hours, Vineyard
Wind should call the relevant regional hotline (Greater Atlantic Region
[Maine through Virginia] Hotline 866-755-6622; Southeast Hotline 877-
WHALE-HELP) with the observation information provided below.
Observation information would include: the time (note time format),
date (MM/DD/YYYY), location (latitude/longitude in decimal degrees;
coordinate system used) of the observation, number of whales, animal
description/certainty of observation (follow up with photos/video if
taken), reporter's contact information, and lease area number/project
name, PSO/personnel name who made the observation, and PSO provider
company (if applicable). If Vineyard Wind is unable to report via the
template or the regional hotline, Vineyard Wind would enter the
sighting via the WhaleAlert app (https://www.whalealert.org/). If this
is not possible, the sighting should be reported to the U.S. Coast
Guard via channel 16. The report to the Coast Guard must include the
same information as would be reported to the hotline (see above). PAM
detections would not be reported to WhaleAlert or the U.S. Coast Guard.
If a non-NARW large whale is observed,
[[Page 31052]]
Vineyard Wind would be required to report the sighting via WhaleAlert
app (https://www.whalealert.org/) as soon as possible but within 24
hours.
In the event that personnel involved in the Project discover a
stranded, entangled, injured, or dead marine mammal, Vineyard Wind must
immediately report the observation to NMFS. If in the Greater Atlantic
Region (Maine through Virginia), call the NMFS Greater Atlantic
Stranding Hotline (866-755-6622), and if in the Southeast Region (North
Carolina through Florida) call the NMFS Southeast Stranding Hotline
(877-WHALE-HELP, 877-942-5343). Separately, Vineyard Wind must report
the incident within 24 hours to NMFS OPR
([email protected]) and, if in the Greater Atlantic
Region to the NMFS GARFO ([email protected]) or if in
the Southeast Region, to the NMFS Southeast Regional Office (SERO;
[email protected]). Note, the stranding hotline may request the
report be sent to the local stranding network response team. The report
must include contact information (e.g., name, phone number, etc.),
time, date, and location (i.e., specify coordinate system) 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),
photographs or video footage of the animal(s) (if available), and
general circumstances under which the animal was discovered.
If the injury, entanglement, or death was caused by a project
activity, Vineyard Wind would be required to immediately cease all
activities until NMFS OPR is able to review the circumstances of the
incident and determine what, if any, additional measures are
appropriate to ensure compliance with the terms of the IHA. NMFS OPR
may impose additional measures to minimize the likelihood of further
prohibited take and ensure MMPA compliance consistent with the adaptive
management provisions. Vineyard Wind could not resume their activities
until notified by NMFS OPR.
In the event of a suspected or confirmed vessel strike of a marine
mammal by any vessel associated with the Project or other means by
which Project activities caused a non-auditory injury or death of a
marine mammal, Vineyard Wind must immediately report the incident to
NMFS. If in the Greater Atlantic Region (Maine through Virginia), call
the NMFS Greater Atlantic Stranding Hotline (866-755-6622), and if in
the Southeast Region (North Carolina through Florida) call the NMFS
Southeast Stranding Hotline (877-WHALE-HELP, 877-942-5343). Separately,
Vineyard Wind must immediately report the incident to NMFS OPR
([email protected]) and, if in the Greater Atlantic
Region to the NMFS GARFO ([email protected]) or if in
the Southeast Region, to the NMFS SERO ([email protected]). The
report must include time, date, and location (i.e., specify coordinate
system)) of the incident, species identification (if known) or
description of the animal(s) involved (i.e., identifiable features
including animal color, presence of dorsal fin, body shape and size,
etc.), vessel strike reporter information (name, affiliation, email for
person completing the report), vessel strike witness (if different than
reporter) information (e.g., name, affiliation, phone number, platform
for person witnessing the event, etc.), vessel name and/or MMSI number;
vessel size and motor configuration (inboard, outboard, jet
propulsion), vessel's speed leading up to and during the incident,
vessel's course/heading and what operations were being conducted (if
applicable), part of vessel that struck marine mammal (if known),
vessel damage notes, status of all sound sources in use at the time of
the strike, if the marine mammal was seen before the strike event,
description of behavior of the marine mammal before the strike event
(if seen) and behavior immediately following the strike, 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, etc.) immediately
preceding the strike, estimated (or actual, if known) size and length
of marine mammal that was struck, if available, description of the
presence and behavior of any other marine mammals immediately preceding
the strike, other animal-specific details if known (e.g., length, sex,
age class), behavior or estimated fate of the marine mammal post-strike
(e.g., dead, injured but alive, injured and moving, external visible
wounds (linear wounds, propeller wounds, non-cutting blunt-force trauma
wounds), blood or tissue observed in the water, status unknown,
disappeared), to the extent practicable, any photographs or video
footage of the marine mammal(s), and, any additional notes the witness
may have from the interaction. For any numerical values provided (i.e.,
location, animal length, vessel length, etc.), please provide if values
are actual or estimated.
Vineyard Wind would be required to immediately cease activities
until the NMFS OPR is able to review the circumstances of the incident
and determine what, if any, additional measures are appropriate to
ensure compliance with the terms of the IHA. NMFS OPR may impose
additional measures to minimize the likelihood of further prohibited
take and ensure MMPA compliance. Vineyard Wind may not resume their
activities until notified by NMFS OPR.
Sound Field Verification--Vineyard Wind would be required to submit
interim SFV reports after each foundation installation within 48 hours.
A final SFV report for all monopile foundation installation monitoring
would be required within 90 days following completion of acoustic
monitoring.
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'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), 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' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
[[Page 31053]]
In the Estimated Take section, we estimated the maximum number of
takes by Level A harassment and Level B harassment that could occur
from Vineyard Wind's specified activities based on the methods
described. The impact that any given take would have is dependent on
many case-specific factors that need to be considered in the negligible
impact analysis (e.g., the context of behavioral exposures such as
duration or intensity of a disturbance, the health of impacted animals,
the status of a species that incurs fitness-level impacts to
individuals, etc.). In this notice of proposed IHA, we evaluate the
likely impacts of the harassment takes that are proposed to be
authorized in the context of the specific circumstances surrounding
these predicted takes. We also collectively evaluate this information,
as well as other more taxa-specific information and mitigation measure
effectiveness, in group-specific discussions that support our
negligible impact conclusions for each stock. As described above, no
serious injury or mortality is expected or proposed to be authorized
for any species or stock.
We base our analysis and preliminary negligible impact
determination on the number of takes that are proposed to be
authorized, and extensive qualitative consideration of other contextual
factors that influence the degree of impact of the takes on the
affected individuals and the number and context of the individuals
affected.
To avoid repetition, we provide some general analysis in this
Negligible Impact Analysis and Determination section that applies to
all the species listed in table 3 given that some of the anticipated
effects of Vineyard Wind's construction activities on marine mammals
are expected to be relatively similar in nature. Where there are
meaningful differences between species or stocks--as is the case of the
NARW--they are included as separate subsections below.
Last, we provide a negligible impact determination for each species
or stock, providing species or stock-specific information or analysis
where appropriate, for example for NARWs given the population status.
Organizing our analysis by grouping species or stocks that share common
traits or that would respond similarly to effects of Vineyard Wind's
activities, and then providing species- or stock-specific information
allows us to avoid duplication while ensuring that we have analyzed the
effects of the specified activities on each affected species or stock.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized in this IHA. Any Level A
harassment proposed to be authorized would be in the form of auditory
injury (i.e., PTS). For all species, the amount of take proposed to be
authorized represents the maximum amount of Level A harassment and
Level B harassment that is reasonably expected to occur.
Behavioral Disturbance
In general, NMFS anticipates that impacts on an individual that has
been harassed are likely to be more intense when exposed to higher
received levels and for a longer duration (though this is in no way a
strictly linear relationship for behavioral effects across species,
individuals, or circumstances) and less severe impacts result when
exposed to lower received levels and for a brief duration. However,
there is also growing evidence of the importance of contextual factors
such as distance from a source in predicting marine mammal behavioral
response to sound--i.e., sounds of a similar level emanating from a
more distant source have been shown to be less likely to evoke a
response of equal magnitude (DeRuiter and Doukara, 2012; Falcone et
al., 2017). As described in the Potential Effects of Specified
Activities on Marine Mammals and their Habitat section, the intensity
and duration of any impact resulting from exposure to Vineyard Wind's
activities is dependent upon a number of contextual factors including,
but not limited to, sound source frequencies, whether the sound source
is moving towards the animal, hearing ranges of marine mammals,
behavioral state at time of exposure, status of individual exposed
(e.g., reproductive status, age class, health) and an individual's
experience with similar sound sources. Southall et al. (2021), Ellison
et al. (2012) and Moore and Barlow (2013), among others, emphasize the
importance of context (e.g., behavioral state of the animals, distance
from the sound source) in evaluating behavioral responses of marine
mammals to acoustic sources. Level B Harassment of marine mammals may
consist of behavioral modifications (e.g., avoidance, temporary
cessation of foraging or communicating, changes in respiration or group
dynamics, masking) and may include auditory impacts in the form of
temporary hearing loss. In addition, some of the lower-level
physiological stress responses (e.g., change in respiration, change in
heart rate) discussed previously would likely co-occur with the
behavioral modifications, although these physiological responses are
more difficult to detect, and fewer data exist relating these responses
to specific received levels of sound. Take by Level B harassment, then,
may have a stress-related physiological component as well; however, we
would not expect Vineyard Wind's pile driving activities to produce
conditions of long-term and continuous exposure to noise leading to
long-term physiological stress responses in marine mammals that could
affect reproduction or survival.
In the range of behavioral effects that might be expected to be
part of a response that qualifies as an instance of Level B harassment
(which by nature of the way it is modeled/counted, occurs within 1
day), the less severe end might include exposure to comparatively lower
levels of a sound, at a greater distance from the animal, for a few or
several minutes. A less severe exposure of this nature could result in
a behavioral response such as avoiding an area that an animal would
otherwise have chosen to move through or feed in for some amount of
time or breaking off one or a few feeding bouts. More severe effects
could occur if an animal gets close enough to the source to receive a
comparatively higher level, is exposed continuously to one source for a
longer time or is exposed intermittently to different sources
throughout a day. Such effects might result in an animal having a more
severe flight response and leaving a larger area for a day or more or
potentially losing feeding opportunities for a day. However, such
severe behavioral effects are expected to occur infrequently.
Many species perform vital functions, such as feeding, resting,
traveling, and socializing on a diel cycle (24-hour cycle). Behavioral
reactions to noise exposure, when taking place in a biologically
important context, such as disruption of critical life functions,
displacement, or avoidance of important habitat, are more likely to be
significant if they last more than 1 day or recur on subsequent days
(Southall et al., 2007) due to diel and lunar patterns in diving and
foraging behaviors observed in many cetaceans (Baird et al., 2008;
Barlow et al., 2020; Henderson et al., 2016; Schorr et al., 2014). It
is important to note the water depth in the LIA is shallow (ranging up
to 37 to 49.5 m), so deep diving species such as sperm whales are not
expected to be engaging in deep foraging dives when exposed to noise
above NMFS harassment thresholds during the specified activities.
Therefore, we do not anticipate impacts to deep foraging behavior to be
impacted by the specified activities.
[[Page 31054]]
It is also important to identify that the estimated number of takes
does not necessarily equate to the number of individual animals
Vineyard Wind expects to harass (which is lower), but rather to the
instances of take (i.e., exposures above the Level B harassment
thresholds) that may occur. Some individuals of a species may
experience recurring instances of take over multiple days throughout
the year while some members of a species or stock may experience one
exposure as they move through an area, which means that the number of
individuals taken is smaller than the total estimated takes. In short,
for species that are more likely to be migrating through the area and/
or for which only a comparatively smaller number of takes are predicted
(e.g., some of the mysticetes), it is more likely that each take
represents a different individual whereas for non-migrating species
with larger amounts of predicted take, we expect that the total
anticipated takes represent exposures of a smaller number of
individuals of which some would be taken across multiple days.
Impact pile driving for foundation installation is anticipated to
have the greatest impacts. For these reasons, impacts are proposed to
be minimized through implementation of mitigation measures, including
use of a sound attenuation system, soft-starts, the implementation of
clearance zones that would facilitate a delay to pile driving
commencement, and implementation of shutdown zones. All these measures
are designed to avoid or minimize harassment. For example, given
sufficient notice through the use of soft-start, marine mammals are
expected to move away from a sound source that is disturbing prior to
becoming exposed to very loud noise levels. The requirement to couple
visual monitoring and PAM before and during all foundation installation
will increase the overall capability to detect marine mammals compared
to one method alone.
Occasional, milder behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations, and even if
some smaller subset of the takes is in the form of a longer (several
hours or a day) and more severe response, if they are not expected to
be repeated over numerous or sequential days, impacts to individual
fitness are not anticipated. Also, the effect of disturbance is
strongly influenced by whether it overlaps with biologically important
habitats when individuals are present--avoiding biologically important
habitats will provide opportunities to compensate for reduced or lost
foraging (Keen et al., 2021). Nearly all studies and experts agree that
infrequent exposures of a single day or less are unlikely to impact an
individual's overall energy budget (Farmer et al., 2018; Harris et al.,
2017; King et al., 2015; National Academy of Science, 2017; New et al.,
2014; Southall et al., 2007; Villegas-Amtmann et al., 2015).
Temporary Threshold Shift
TTS is one form of Level B harassment that marine mammals may incur
through exposure to US Wind's activities and, as described earlier, the
proposed takes by Level B harassment may represent takes in the form of
direct behavioral disturbance, TTS, or both. As discussed in the
Potential Effects of Specified Activities on Marine Mammals and their
Habitat section, in general, TTS can last from a few minutes to days,
be of varying degree, and occur across different frequency bandwidths,
all of which determine the severity of the impacts on the affected
individual, which can range from minor to more severe. Impact pile
driving is a broadband noise sources but generates sounds in the lower
frequency ranges (with most of the energy below 1-2 kHz, but with a
small amount energy ranging up to 20 kHz); therefore, in general and
all else being equal, we would anticipate the potential for TTS is
higher in low-frequency cetaceans (i.e., mysticetes) than other marine
mammal hearing groups and would be more likely to occur in frequency
bands in which they communicate. However, we would not expect the TTS
to span the entire communication or hearing range of any species given
that the frequencies produced by these activities do not span entire
hearing ranges for any particular species. Additionally, though the
frequency range of TTS that marine mammals might sustain would overlap
with some of the frequency ranges of their vocalizations, the frequency
range of TTS from Vineyard Wind's pile driving activities would not
typically span the entire frequency range of one vocalization type,
much less span all types of vocalizations or other critical auditory
cues for any given species. In addition, the proposed mitigation
measures further reduce the potential for TTS in mysticetes.
Generally, both the degree of TTS and the duration of TTS would be
greater if the marine mammal is exposed to a higher level of energy
(which would occur when the peak dB level is higher or the duration is
longer). The threshold for the onset of TTS was discussed previously
(see Estimated Take). An animal would have to approach closer to the
source or remain in the vicinity of the sound source appreciably longer
to increase the received SEL, which would be unlikely considering the
proposed mitigation and the nominal speed of the receiving animal
relative to the stationary sources such as impact pile driving. The
recovery time of TTS is also of importance when considering the
potential impacts from TTS. In TTS laboratory studies (as discussed in
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat), some using exposures of almost an hour in duration or up to
217 SEL, almost all individuals recovered within 1 day (or less, often
in minutes), and we note that while the pile driving activities last
for hours a day, it is unlikely that most marine mammals would stay in
the close vicinity of the source long enough to incur more severe TTS.
Overall, given the few instances in which any individual might incur
TTS, the low degree of TTS and the short anticipated duration, and the
unlikely scenario that any TTS would overlap the entirety of an
individual's critical hearing range, it is unlikely that TTS (of the
nature expected to result from the project's activities) would result
in behavioral changes or other impacts that would impact any
individual's (of any hearing sensitivity) reproduction or survival.
Permanent Threshold Shift
NMFS proposes to authorize a very small amount of take by PTS to
some marine mammal individuals. The numbers of proposed takes by Level
A harassment are relatively low for all marine mammal stocks and
species (table 11). We anticipate that PTS may occur from exposure to
impact pile driving, which produces sounds that are both impulsive and
primarily concentrated in the lower frequency ranges (below 1 kHz)
(David, 2006; Krumpel et al., 2021).
There are no PTS data on cetaceans and only one instance of PTS
being induced in older harbor seals (Reichmuth et al., 2019). However,
available TTS data (of mid-frequency hearing specialists exposed to
mid- or high-frequency sounds (Southall et al., 2007, 2019; NMFS,
2018)) suggest that most threshold shifts occur in the frequency range
of the source up to one octave higher than the source. We would
anticipate a similar result for PTS. Further, no more than a small
degree of PTS is expected to be associated with any of the incurred
Level A harassment, given it is unlikely that animals would stay in the
close vicinity of a source for a duration long enough to produce more
than a small degree of PTS.
PTS would consist of minor degradation of hearing capabilities
[[Page 31055]]
occurring predominantly at frequencies one-half to one octave above the
frequency of the energy produced by pile driving (i.e., the low-
frequency region below 2 kHz) (Cody and Johnstone, 1981; McFadden,
1986; Finneran, 2015), not severe hearing impairment. If hearing
impairment occurs from impact pile driving, it is most likely that the
affected animal would lose a few decibels in its hearing sensitivity,
which in most cases is not likely to meaningfully affect its ability to
forage and communicate with conspecifics. In addition, during impact
pile driving, given sufficient notice through use of soft-start prior
to implementation of full hammer energy during impact pile driving,
marine mammals are expected to move away from a sound source that is
disturbing prior to it resulting in severe PTS.
Auditory Masking or Communication Impairment
The potential impacts of masking on an individual are similar to
those discussed for TTS (e.g., decreased ability to communicate, forage
effectively, or detect predators), but an important difference is that
masking only occurs during the period of the signal, versus TTS, which
continues beyond the duration of the signal. Also, though masking can
result from the sum of exposure to multiple signals, none of these
signals might individually cause TTS. Fundamentally, masking is
referred to as a chronic effect because one of the key potential
harmful components of masking is the fact that an animal would have
reduced ability to hear or interpret critical cues. This becomes much
more likely to cause a problem the longer it is occurring. Inherent in
the concept of masking is the fact that the potential for the effect is
only present during the times that the animal and the source are in
close enough proximity for the effect to occur (and further, this time
period would need to coincide with a time that the animal was utilizing
sounds at the masked frequency).
As our analysis has indicated, we expect that impact pile driving
may occur for several, albeit intermittent, hours per day, for multiple
days. Masking is fundamentally more of a concern at lower frequencies
(which are pile driving dominant frequencies), because low-frequency
signals propagate significantly further than higher frequencies and
because they are more likely to overlap both the narrower low-frequency
calls of mysticetes, as well as many non-communication cues related to
fish and invertebrate prey, and geologic sounds that inform navigation.
As mentioned above (see Description of Marine Mammals in the Area of
Specified Activities), the LIA does not overlap critical habitat or
BIAs for any species, and temporary avoidance of the pile driving area
by marine mammals would likely displace animals to areas of sufficient
habitat. In summary, the nature of Vineyard Wind's activities, paired
with habitat use patterns by marine mammals, does not support the
likelihood of take due to masking effects or that masking would have
the potential to affect reproductive success or survival, and are we
not proposing to authorize such take.
Impact on Habitat and Prey
Construction activities may result in fish and invertebrate
mortality or injury very close to the source, and Vineyard Wind's
activities may cause some fish to leave the area of disturbance. It is
anticipated that any mortality or injury would be limited to a very
small subset of available prey and the implementation of mitigation
measures such as the use of a noise attenuation system during impact
pile driving would further limit the degree of impact. Behavioral
changes in prey in response to construction activities could
temporarily impact marine mammals' foraging opportunities in a limited
portion of the foraging range but, because of the relatively small area
of the habitat that may be affected at any given time (e.g., around a
pile being driven) and the temporary nature of the disturbance on prey
species, the impacts to marine mammal habitat are not expected to cause
significant or long-term negative consequences. There is no indication
that displacement of prey would impact individual fitness and health,
particularly since unconsumed prey would likely still be available in
the environment in most cases following the cessation of acoustic
exposure.
Cable presence is not anticipated to impact marine mammal habitat,
as these would be buried, and any electromagnetic fields emanating from
the cables are not anticipated to result in consequences that would
impact marine mammals' prey to the extent they would be unavailable for
consumption. Although many species of marine mammal prey can detect
electromagnetic fields, previous studies have shown little impacts on
habitat use (Hutchinson et al., 2018). Burying the cables and the
inclusion of protective shielding on cables will also minimize any
impacts of electromagnetic fields on marine mammal prey.
The presence of wind turbines within the Lease Area could have
longer-term impacts on marine mammal habitat, as the project would
result in the persistence of the structures within marine mammal
habitat for more than 30 years. For piscivorous marine mammal species,
the presence of structures could result in a beneficial reef effect
which may lead to increases in the availability of prey. However,
turbine presence and operation is, generally likely to result in
certain oceanographic effects in the marine environment, and may
adversely alter aggregations and distribution of marine mammal
zooplankton prey through changing the strength of tidal currents and
associated fronts, changes in stratification, primary production, the
degree of mixing, and stratification in the water column (Chen et al.,
2021; Johnson et al., 2021; Christiansen et al., 2022; Dorrell et al.,
2022). In the recently released BOEM and NOAA Fisheries North Atlantic
Right Whale Strategy (BOEM et al., 2024), the agencies identify the
conceptual pathway by which changes to ocean circulation could
potentially lead to fitness reduction of North Atlantic right whales,
who primarily forage on copepods (see figure 2). As described in the
Potential Effects to Marine Mammal Habitat section, there is
uncertainty regarding the intensity (or magnitude) and spatial extent
of turbine operation impacts on marine mammals habitat, including
planktonic prey. Recently, a National Academy of Sciences, Engineering,
and Medicine panel of independent experts concluded that the impacts of
offshore wind operations on North Atlantic right whales and their
habitat in the Nantucket Shoals region is uncertain due to the limited
data available at this time and recognized what data is available is
largely based on models from the North Sea that have not been validated
by observations (NAS, 2023). The report also identifies that major
oceanographic changes have occurred to the Nantucket Shoals region over
the past 25 years and it will be difficult to isolate from the much
larger variability introduced by natural and other anthropogenic
sources (including climate change).
As discussed in the Description of the Specified Activity section,
this IHA addresses the take incidental to the installation of 15
foundations, which will gradually become operational following
construction completion. While there are likely to be oceanographic
impacts from the presence of operating turbines, meaningful
oceanographic impacts relative to stratification and mixing that would
significantly affect marine
[[Page 31056]]
mammal foraging and prey over large areas in key foraging habitats,
resulting in the reproduction or survival of any individual marine
mammals, are not anticipated from the Vineyard Wind activities covered
under this proposed IHA, yet are likely to be comparatively minor, if
impacts do occur.
Mitigation To Reduce Impacts on All Species
The proposed IHA includes a variety of mitigation measures designed
to minimize impacts on all marine mammals, with a focus on NARWs (the
latter is described in more detail below). For impact pile driving of
foundation piles, 10 overarching mitigation measures are proposed,
which are intended to reduce both the number and intensity of marine
mammal takes: (1) seasonal/time of day work restrictions; (2) use of
multiple PSOs to visually observe for marine mammals (with any
detection within specifically designated zones triggering a delay or
shutdown); (3) use of PAM to acoustically detect marine mammals, with a
focus on detecting baleen whales (with any detection within designated
zones triggering delay or shutdown); (4) implementation of clearance
zones; (5) implementation of shutdown zones; (6) use of soft-start; (7)
use of noise attenuation technology; (8) maintaining situational
awareness of marine mammal presence through the requirement that any
marine mammal sighting(s) by Vineyard Wind's personnel must be reported
to PSOs; (9) sound field verification monitoring; and (10) Vessel
Strike Avoidance measures to reduce the risk of a collision with a
marine mammal and vessel.
The Proposed Mitigation section discusses the manner in which the
required mitigation measures reduce the magnitude and/or severity of
the take of marine mammals, including the following. For activities
with large harassment isopleths, Vineyard Wind would be required to
reduce the noise levels generated to the lowest levels practicable. Use
of a soft-start during impact pile driving will allow animals to move
away from (i.e., avoid) the sound source prior to applying higher
hammer energy levels needed to install the pile (Vineyard Wind would
not use a hammer energy greater than necessary to install piles).
Clearance zone and shutdown zone implementation, which are required
when marine mammals are within given distances associated with certain
impact thresholds for all activities, would reduce the magnitude and
severity of marine mammal take. Additionally, the use of multiple PSOs,
PAM, and maintaining awareness of marine mammal sightings reported in
the region would aid in detecting marine mammals that would trigger the
implementation of the mitigation measures.
Mysticetes
Five mysticete species (comprising five stocks) of cetaceans (NARW,
humpback whale, fin whale, sei whale, and minke whale) may be taken by
harassment. These species, to varying extents, utilize the specific
geographic region, including the LIA, for the purposes of migration,
foraging, and socializing. Mysticetes are in the low-frequency hearing
group.
Behavioral data on mysticete reactions to pile driving noise are
scant. Kraus et al. (2019) predicted that the three main impacts of
offshore wind farms on marine mammals would consist of displacement,
behavioral disruptions, and stress. Broadly, we can look to studies
that have focused on other noise sources such as seismic surveys and
military training exercises, which suggest that exposure to loud
signals can result in avoidance of the sound source (or displacement if
the activity continues for a longer duration in a place where
individuals would otherwise have been staying, which is less likely for
mysticetes in this area), disruption of foraging activities (if they
are occurring in the area), local masking around the source, associated
stress responses, and impacts to prey, as well as TTS or PTS in some
cases.
Mysticetes encountered in the LIA are expected to be migrating
through and/or engaged in foraging behavior. The extent to which an
animal engages in these behaviors in the area is species-specific and
varies seasonally. Many mysticetes are expected to predominantly be
migrating through the LIA towards or from primary feeding habitats
(e.g., Cape Cod Bay, Great South Channel, and Gulf of St. Lawrence).
While we have acknowledged above that mortality, hearing impairment, or
displacement of mysticete prey species may result locally from impact
pile driving, given the very short duration of and broad availability
of prey species in the area and the availability of alternative
suitable foraging habitat for the mysticete species most likely to be
affected, any impacts on mysticete foraging are expected to be minor.
Whales temporarily displaced from the LIA are 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 habitats, including to the east near Nantucket
Shoals. In addition, any displacement of whales or interruption of
foraging bouts would be expected to be relatively temporary in nature.
The potential for repeated exposures of individuals is dependent
upon their residency time, with migratory animals unlikely to be
exposed on repeated occasions and animals remaining in the area more
likely to be exposed more than once. For mysticetes, where relatively
low numbers of species-specific take by Level B harassment are
predicted (compared to the abundance of each mysticete species or
stock; see table 11) and movement patterns suggest that individuals
would not necessarily linger in a particular area for multiple days,
each predicted take likely represents an exposure of a different
individual; with perhaps a subset of takes for a few species
potentially representing a few repeated of a limited number of
individuals across multiple days. In other words, the behavioral
disturbance to any individual mysticete would, therefore, be expected
to most likely occur within a single day, or potentially across a few
days, and therefore would not be expected to impact the animal's
fitness for reproduction or survival.
In general, the duration of exposures would not be continuous
throughout any given day and pile driving would not occur on all
consecutive days due to weather delays or any number of logistical
constraints Vineyard Wind has identified. Species-specific analysis
regarding potential for repeated exposures and impacts is provided
below.
Humpback whales, minke whales, fin whales and sei whales are the
mysticete species for which PTS is anticipated and proposed to be
authorized. As described previously, PTS for mysticetes from some
project activities may overlap frequencies used for communication,
navigation, or detecting prey. However, given the nature and duration
of the activity, the mitigation measures, and likely avoidance
behavior, any PTS is expected to be of a small degree, would be limited
to frequencies where pile driving noise is concentrated (i.e., only a
small subset of their expected hearing range) and would not be expected
to impact individuals' fitness for reproductive success or survival.
NARWs
NARWs are listed as endangered under the ESA and as both depleted
and strategic under the MMPA. As described in the Potential Effects to
Marine Mammals and Their Habitat section, NARWs are threatened by a low
population abundance, higher than
[[Page 31057]]
average mortality rates, and lower than average reproductive rates.
Recent studies have reported individuals showing high stress levels
(e.g., Corkeron et al., 2017) and poor health, which has further
implications on reproductive success and calf survival (Christiansen et
al., 2020; Stewart et al., 2021, 2022). As described below, a UME has
been designated for NARWs. Given this, the status of the NARW
population is of heightened concern and, therefore, merits additional
analysis and consideration.
This proposed IHA would authorize seven takes of NARW by Level B
harassment only, which equates to approximately 2.1 percent of the
stock's abundance, if each take were considered to be of a different
individual. No Level A harassment, serious injury, or mortality is
anticipated or proposed to be authorized for this species.
As described in the Description of Marine Mammals in the Area of
Specified Activities section, NARWs are presently experiencing an
ongoing UME (beginning in June 2017). Preliminary findings support
human interactions, specifically vessel strikes and entanglements, as
the cause of death for the majority of NARWs. Given the current status
of the NARW, the loss of even one individual could significantly impact
the population. Level B harassment of NARWs resulting from the
Project's activities is expected to primarily be in the form of
temporary avoidance of the immediate area of construction. Required
mitigation measures will ensure the least practicable adverse impact
and the proposed number of takes of NARWs would not exacerbate or
compound the effects of the ongoing UME.
In general, NARWs in the LIA are expected to be engaging in
migratory, feeding, and/or social behavior. Migrating NARWs would
typically be moving through the LIA, rather than lingering for extended
periods of time (thereby limiting the potential for repeat exposures);
however, foraging whales may remain in the LIA, with an average
residence time of 13 days between December and May (Quintana-Rizzo et
al., 2021). SNE, including the LIA, is part of a known migratory
corridor for NARWs and may be a stopover site for migrating NARWs
moving to or from southeastern calving grounds and northern foraging
grounds. NARWs are primarily concentrated in the northeastern and
southeastern sections of the Massachusetts Wind Energy Area (MA WEA)
(i.e., east of the LIA) during the summer (June-August) and winter
(December-February) while distribution likely shifts to the west,
closer to the LIA, into the Rhode Island/Massachusetts Wind Energy Area
(RI/MA WEA) in the spring (March-May) (Quintana-Rizzo et al., 2021).
However, NARWs range outside of the LIA for their main feeding,
breeding, and calving activities. It is important to note that there
would be a restriction on impact pile driving activities from January
through May, with pile driving only allowed in December with approval
from NMFS and BOEM.
Foundation installation is of concern, given loud sound levels.
However, as described above, foundation installation would only occur
during times when, based on the best available scientific data, NARWs
are less frequently encountered and less likely to be engaged in
critical foraging behavior (although NMFS recognizes NARWs may forage
year-round in SNE). The potential types, severity, and magnitude of
impacts are also anticipated to mirror that described in the general
Mysticetes section above, including avoidance (the most likely
outcome), changes in foraging or vocalization behavior, masking, a
small amount of TTS, and temporary physiological impacts (e.g., change
in respiration, change in heart rate). Importantly, the effects of the
activities are expected to be sufficiently low-level and localized to
specific areas as to not meaningfully impact important behaviors such
as migration and foraging for NARWs. As noted above, for NARWs, this
IHA would authorize up to seven takes, by Level B harassment. These
takes are expected to be in the form of temporary behavioral
disturbance, such as slight displacement (but not abandonment) of
migratory habitat or temporary cessation of feeding. Further, given
many of these exposures are generally expected to occur to different
individual right whales migrating through (i.e., many individuals would
not be impacted on more than 1 day in a year), with some subset
potentially being exposed on no more than a few days within the year,
they are unlikely to result in energetic consequences that could affect
reproduction or survival of any individuals.
Overall, NMFS expects that any behavioral harassment of NARWs
incidental to the specified activities would not result in changes to
their migration patterns or foraging success, as only temporary
avoidance of an area during construction is expected to occur. As
described previously, NARWs migrate, forage, or socialize in the LIA
but are not expected to remain in this habitat for extensive durations
relative to core foraging habitats to the east, south of Nantucket and
Martha's Vineyard, Cape Cod Bay, or the Great South Channel (Quintana-
Rizzo et al., 2021). Any temporarily displaced animals would be able to
return to or continue to travel through the LIA and subsequently
utilize this habitat once activities have ceased.
Although acoustic masking may occur in the vicinity of the
foundation installation activities, based on the acoustic
characteristics of noise associated with pile driving (e.g., frequency
spectra, short duration of exposure, NMFS expects masking effects to be
minimal during impact pile driving). In addition, masking would likely
only occur during the period of time that a NARW is in the relatively
close vicinity of pile driving, which is expected to be intermittent
within a day and confined to the months in which NARWs are at lower
densities and primarily moving through the area. TTS,could also occur
in some of the exposed animals, making it more difficult for those
individuals to hear or interpret acoustic cues within the frequency
range (and slightly above) of sound produced during impact pile
driving; however, any TTS would likely be of low amount, limited
duration, and limited to frequencies where most construction noise is
centered (below 2 kHz). NMFS expects that right whale hearing
sensitivity would return to pre-exposure levels shortly after migrating
through the area or moving away from the sound source.
As described in the Potential Effects to Marine Mammals and Their
Habitat section of this notice, the distance of the receiver from the
source influences the severity of response, with greater distances
typically eliciting less severe responses. NMFS recognizes NARWs
migrating could be pregnant females (in the fall) and cows with older
calves (in spring) and that these animals may slightly alter their
migration course in response to any foundation pile driving; however,
we anticipate that course diversion would be of small magnitude. Hence,
while some avoidance of the pile-driving activities may occur, we
anticipate any avoidance behavior of migratory NARWs would be similar
to that of gray whales (Tyack et al., 1983), on the order of hundreds
of meters up to 1 to 2 km. This diversion from a migratory path
otherwise uninterrupted by the project's activities is not expected to
result in meaningful energetic costs that would impact annual rates of
recruitment of survival. NMFS expects that NARWs would be able to avoid
areas during periods of active noise production while not being forced
out of this portion of their habitat.
[[Page 31058]]
NARW presence in the LIA is year-round. However, abundance during
summer months is lower compared to the winter months with spring and
fall serving as ``shoulder seasons'' wherein abundance waxes (fall) or
wanes (spring). Even in consideration of recent habitat use and
distribution shifts, Vineyard Wind would still be installing monopile
foundations when the presence of NARWs is expected to be lower.
Given this year-round habitat usage, in recognition that where and
when whales may actually occur during project activities is unknown as
it depends on the annual migratory behaviors, NMFS is requiring a suite
of mitigation measures designed to reduce impacts to NARWs to the
maximum extent practicable. These mitigation measures (e.g., seasonal/
daily work restrictions, vessel separation distances, and reduced
vessel speed) would not only avoid the likelihood of vessel strikes but
also would minimize the severity of behavioral disruptions (e.g.,
through sound reduction using attenuation systems and reduced temporal
overlap of project activities and NARWs). This would help further
ensure that takes by Level B harassment that are estimated to occur
would not affect reproductive success or survivorship of individuals
through detrimental impacts to energy intake or cow/calf interactions
during migratory transit.
As described in the Description of Marine Mammals in the Area of
Specified Activities section, the Vineyard Wind Offshore Wind Project
is being constructed within the NARW migratory corridor BIA, which
represents areas and months within which a substantial portion of a
species or population is known to migrate. The area over which NARWs
may be harassed is relatively small compared to the width of the
migratory corridor. The width of the migratory corridor in this area is
approximately 210.1 km (while the width of the Lease Area, at the
longest point at which it crosses the BIA, is approximately 14.5 km).
NARWs may be displaced from their normal path and preferred habitat in
the immediate activity area (primarily from pile driving activities),
however, we do not anticipate displacement to be of high magnitude
(e.g., beyond a few kilometers); therefore, any associated bio-
energetic expenditure is anticipated to be small. Although NARWs may
forage in the LIA, there are no known breeding or calving areas within
the LIA. Prey species are mobile (e.g., calanoid copepods can initiate
rapid and directed escape responses) and are broadly distributed
throughout the LIA. Therefore, any impacts to prey that may occur are
also unlikely to impact marine mammals.
The most significant measure to minimize impacts to individual
NARWs is the seasonal moratorium on all foundation installation
activities from January 1 through May 31 and the limitation on these
activities in December (e.g., only work with approval from NMFS) when
NARW abundance in the LIA is expected to be highest. NMFS also expects
this measure to greatly reduce the potential for mother-calf pairs to
be exposed to impact pile driving noise above the Level B harassment
threshold during their annual spring migration through SNE from calving
grounds to primary foraging grounds (e.g., Cape Cod Bay). NMFS expects
that the severity of any take of NARWs would be reduced due to the
mitigation measures that would ensure that any exposures above the
Level B harassment threshold would result in only short-term effects to
individuals exposed.
Foundation installation may only begin in the absence of NARWs
(based on visual and passive acoustic monitoring). Once foundation
installation activities have commenced, NMFS anticipates NARWs would
avoid the area, utilizing nearby waters to carry on pre-exposure
behaviors. However, foundation installation activities must be shut
down if a NARW is sighted at any distance or acoustically detected at
any distance within the PAM monitoring zone, unless a shutdown is not
feasible due to risk of injury or loss of life. Shutdown would be
required anywhere if NARWs are detected within or beyond the Level B
harassment zone, further minimizing the duration and intensity of
exposure. These measures are designed to avoid PTS and also reduce the
severity of Level B harassment, including the potential for TTS. While
some TTS could occur, given the mitigation measures (e.g., delay pile
driving upon a sighting or acoustic detection and shutting down upon a
sighting or acoustic detection), the potential for TTS to occur is low.
NMFS anticipates that if NARWs go undetected and they are exposed to
foundation installation noise, it is unlikely a NARW would approach the
sound source locations to the degree that they would expose themselves
to very high noise levels. This is because typical observed whale
behavior demonstrates likely avoidance of harassing levels of sound
where possible (Richardson et al., 1985).
The clearance and shutdown measures are most effective when
detection efficiency is maximized, as the measures are triggered by a
sighting or acoustic detection. To maximize detection efficiency, NMFS
would require the combination of PAM and visual observers. NMFS also
would require communication protocols with other project vessels and
other heightened awareness efforts (e.g., daily monitoring of NARW
sighting databases) such that as a NARW approaches the source (and
thereby could be exposed to higher noise energy levels), PSO detection
efficacy would increase, the whale would be detected, and a delay to
commencing foundation installation or shutdown (if feasible) would
occur. In addition, the implementation of a soft-start for impact pile
driving would provide an opportunity for whales to move away from the
source if they are undetected, reducing received levels.
As described above, no serious injury or mortality, or Level A
harassment of NARWs is anticipated or proposed to be authorized.
Extensive NARW-specific mitigation measures (beyond the robust suite
required for all species) are expected to further minimize the amount
and severity of Level B harassment.
Given the documented habitat use within the LIA, the seven
instances of take by Level B harassment could include seven whales
disturbed on one day each within the year, or it could represent a
smaller number of whales impacted on 2 or 3 days, should NARWs briefly
use the LIA as a ``stopover'' site and stay or swim in and out of the
LIA for more than day. At any rate, any impacts to NARWs are expected
to be in the form of lower level behavioral disturbance, given the
extensive mitigation measures.
Given the magnitude and severity of the impacts discussed above,
and in consideration of the required mitigation and other information
presented, Vineyard Wind's activities are not expected to result in
impacts on the reproduction or survival of any individuals, much less
affect annual rates of recruitment or survival. For these reasons, we
have determined that the take (by Level B harassment) anticipated and
proposed to be authorized would have a negligible impact on the NARW.
Fin Whale
The fin whale is listed as endangered under the ESA, and the
western North Atlantic stock is considered both depleted and strategic
under the MMPA. No UME has been designated for this species or stock.
No serious injury or
[[Page 31059]]
mortality is anticipated or proposed to be authorized for this species.
This IHA would authorize up to seven takes, by harassment only,
over the 1 year period. The maximum allowable take by Level A
harassment and Level B harassment, is one and six, respectively (which
equates to approximately 0.10 percent of the stock abundance, if each
take were considered to be of a different individual). Given the close
proximity of a fin whale feeding BIA (2,933 km\2\) from March through
October, and that SNE is generally considered a feeding area, it is
likely that the seven takes could represent a few whales taken 2-3
times annually.
Level B harassment is expected to be in the form of behavioral
disturbance, primarily avoidance of the LIA where foundation
installation is occurring and some low-level TTS and masking that may
limit the detection of acoustic cues for relatively brief periods of
time. We anticipate any potential PTS would be minor (limited to a few
dB), and any PTS or TTS would be concentrated at half or one octave
above the frequency band of pile driving noise (most sound is below 2
kHz) which does not include the full predicted hearing range of fin
whales. If TTS is incurred, hearing sensitivity would likely return to
pre-exposure levels relatively shortly after exposure ends. Any masking
or physiological responses would also be of low magnitude and severity
for reasons described above.
Fin whales are present in the waters off of New England year-round
and are one of the most frequently observed large whales and cetaceans
in continental shelf waters, principally from Cape Hatteras, North
Carolina in the Mid-Atlantic northward to Nova Scotia, Canada
(Sergeant, 1977; Sutcliffe and Brodie, 1977; CETAP, 1982; Hain et al.,
1992; Geo-Marine, 2010; BOEM 2012; Edwards et al., 2015; Hayes et al.,
2023). In SNE, fin whales densities are highest in the spring and
summer months (Kraus et al., 2016; Roberts et al., 2023) though
detections do occur in spring and fall (Watkins et al., 1987; Clark and
Gagnon, 2002; Geo-Marine, 2010; Morano et al., 2012; Van Parijs et al.,
2023). However, fin whales feed more extensively in waters in the Great
South Channel north to the Gulf Maine into the Gulf of St. Lawrence,
areas north and east of the LIA (Hayes et al., 2023).
As described previously, the LIA is in close proximity
(approximately 8.0 km; 5.0 mi) to a small fin whale feeding BIA (2,933
km\2\) east of Montauk Point, New York (figure 2.3 in LaBrecque et al.,
2015) that is active from March to October. Foundation installations
have seasonal work restrictions (i.e., spatial and temporal) such that
the temporal overlap between the specified activities and the active
BIA timeframe would exclude the months of March, April, and May. A
separate larger year-round feeding BIA (18,015 km\2\) located to the
east in the southern Gulf of Maine does not overlap with the LIA and is
located substantially further away (approximately 76.4 km (47.5 mi)),
and would thus not be impacted by project activities. We anticipate
that if foraging is occurring in the LIA and foraging whales are
exposed to noise levels of sufficient strength, they would avoid the
LIA and move into the remaining area of the feeding BIA that would be
unaffected to continue foraging without substantial energy expenditure
or, depending on the time of year, travel to the larger year-round
feeding BIA.
Given the documented habitat use within the area, some of the
individuals taken would likely be exposed on multiple days. However,
low level impacts are generally expected from any fin whale exposure.
Given the magnitude and severity of the impacts discussed above
(including no more than seven takes over the course of the IHA, and a
maximum allowable take by Level A harassment and Level B harassment of
one and six, respectively) and in consideration of the required
mitigation and other information presented, Vineyard Wind's activities
are not expected to result in impacts on the reproduction or survival
of any individuals, much less affect annual rates of recruitment or
survival. For these reasons, we have determined that the take by
harassment anticipated and proposed to be authorized will have a
negligible impact on the western North Atlantic stock of fin whales.
Humpback Whale
The West Indies DPS of humpback whales is not listed as threatened
or endangered under the ESA but the Gulf of Maine stock, which includes
individuals from the West Indies DPS, is considered strategic under the
MMPA. However, as described in the Description of Marine Mammals in the
Area of Specified Activities section, humpback whales along the
Atlantic Coast have been experiencing an active UME as elevated
humpback whale mortalities have occurred along the Atlantic coast from
Maine through Florida since January 2016. Of the cases examined,
approximately 40 percent had evidence of human interaction (vessel
strike or entanglement). Despite the UME, the relevant population of
humpback whales (the West Indies breeding population, or DPS of which
the Gulf of Maine stock is a part) remains stable at approximately
12,000 individuals and takes of humpback whales proposed for
authorization would not exacerbate or compound the effects of the
ongoing UME.
This IHA would authorize up to six takes by harassment only, over
the 1 year period. The maximum allowable take by Level A harassment and
Level B harassment is two and four, respectively (this equates to
approximately 0.43 percent of the stock abundance, if each take were
considered to be of a different individual). Given that feeding is
considered the principal activity of humpback whales in SNE waters,
these takes could represent a few whales exposed two or three times
during the year.
In the western North Atlantic, humpback whales feed during spring,
summer, and fall over a geographic range encompassing the eastern coast
of the U.S. Feeding is generally considered to be focused in areas
north of the LIA, including in a feeding BIA in the Gulf of Maine/
Stellwagen Bank/Great South Channel, but has been documented off the
coast of SNE and as far south as Virginia (Swingle et al., 1993).
Foraging animals tend to remain in the area for extended durations to
capitalize on the food sources.
Assuming humpback whales who are feeding in waters within or
surrounding the LIA behave similarly, we expect that the predicted
instances of disturbance could consist of some individuals that may be
exposed on multiple days if they are utilizing the area as foraging
habitat. As with other baleen whales, if migrating, such individuals
would likely be exposed to noise levels from the project above the
harassment thresholds only once during migration through the LIA.
For all the reasons described in the Mysticetes section above, we
anticipate any potential PTS and TTS would be concentrated at half or
one octave above the frequency band of pile driving noise (most sound
is below 2 kHz) which does not include the full predicted hearing range
of baleen whales. If TTS is incurred, hearing sensitivity would likely
return to pre-exposure levels relatively shortly after exposure ends.
Any masking or physiological responses would also be of low magnitude
and severity for reasons described above.
Given the magnitude and severity of the impacts discussed above
(including no more than six takes over the course of the 1-year IHA,
and a maximum allowable take by Level A harassment and Level B
harassment of two and four, respectively), and in consideration of
[[Page 31060]]
the proposed mitigation measures and other information presented,
Vineyard Wind's activities are not expected to result in impacts on the
reproduction or survival of any individuals, much less affect annual
rates of recruitment or survival. For these reasons, we have determined
that the take by harassment anticipated and proposed to be authorized
will have a negligible impact on the Gulf of Maine stock of humpback
whales.
Minke Whale
Minke whales are not listed under the ESA, and the Canadian East
Coast stock is neither considered depleted nor strategic under the
MMPA. There are no known areas of specific biological importance in or
adjacent to the LIA. As described in the Description of Marine Mammals
in the Area of Specified Activities section, a UME has been designated
for this species but is pending closure. No serious injury or mortality
is anticipated or proposed to be authorized for this species.
This IHA would authorize up to 1 take by Level A harassment and 28
takes by Level B harassment over the 1-year period (equating to
approximately 0.13 percent of the stock abundance, if each take were
considered to be of a different individual). As described in the
Description of Marine Mammals in the Area of Specified Activities
section, minke whales inhabit coastal waters during much of the year
and are common offshore the U.S. eastern seaboard with a strong
seasonal component in the continental shelf and in deeper, off-shelf
waters (CETAP, 1982; Hayes et al., 2022; Hayes et al., 2023). Spring
through fall are times of relatively widespread and common acoustic
occurrence on the continental shelf. From September through April,
minke whales are frequently detected in deep-ocean waters throughout
most of the western North Atlantic (Clark and Gagnon, 2002; Risch et
al., 2014; Hayes et al., 2023). Because minke whales are migratory and
their known feeding areas are north and east of the LIA, including a
feeding BIA in the southwestern Gulf of Maine and George's Bank, they
would be more likely to be transiting through (with each take
representing a separate individual), though it is possible that some
subset of the individual whales exposed could be taken up to a few
times during the effective period of the IHA.
As previously detailed in the Description of Marine Mammals in the
Area of Specified Activities section, there is a UME for minke whales
along the Atlantic coast, from Maine through South Carolina, with the
highest number of deaths in Massachusetts, Maine, and New York.
Preliminary findings in several of the whales have shown evidence of
human interactions or infectious diseases. However, we note that the
population abundance is greater than 21,000, and the take by harassment
proposed to be authorized through this action is not expected to
exacerbate the UME.
We anticipate the impacts of this harassment to follow those
described in the general Mysticetes section above. Any potential PTS
would be minor (limited to a few dB) and any PTS or TTS would be of
short duration and concentrated at half or one octave above the
frequency band of pile driving noise (most sound is below 2 kHz) which
does not include the full predicted hearing range of minke whales. If
TTS is incurred, hearing sensitivity would likely return to pre-
exposure levels relatively shortly after exposure ends. Level B
harassment would be temporary, with primary impacts being temporary
displacement from the LIA but not abandonment of any migratory or
foraging behavior.
Given the magnitude and severity of the impacts discussed above
(including no more than 29 takes of the course of the 1-year IHA, and a
maximum allowable take by Level A harassment and Level B harassment of
1 and 28, respectively), and in consideration of the proposed
mitigation and other information presented, Vineyard Wind's activities
are not expected to result in impacts on the reproduction or survival
of any individuals, much less affect annual rates of recruitment or
survival. For these reasons, we have determined that the take by
harassment anticipated and proposed to be authorized will have a
negligible impact on the Canadian Eastern Coastal stock of minke
whales.
Sei Whale
Sei whales are listed as endangered under the ESA, and the Nova
Scotia stock is considered both depleted and strategic under the MMPA.
There are no known areas of specific biological importance in or
adjacent to the LIA, and no UME has been designated for this species or
stock. No serious injury or mortality is anticipated or proposed to be
authorized for this species.
The IHA would authorize up to three takes by harassment over the 1-
year period. The maximum allowable take by Level A harassment and Level
B harassment is one and two, respectively (combined, this annual take
(n=3) equates to approximately 0.05 percent of the stock abundance, if
each take were considered to be of a different individual). As
described in the Description of Marine Mammals in the Area of Specified
Activities section, most of the sei whale distribution is concentrated
in Canadian waters and seasonally in northerly United States waters,
although they can occur year-round in SNE. Because sei whales are
migratory and their known feeding areas are east and north of the LIA
(e.g., there is a feeding BIA in the Gulf of Maine), they would be more
likely to be moving through (i.e., not foraging) and considering this
and the very low number of total takes, it is unlikely that any
individual would be exposed more than once within the effective period
of the IHA.
With respect to the severity of those individual takes by Level B
harassment, we anticipate impacts to be limited to low-level, temporary
behavioral responses with avoidance and potential masking impacts in
the vicinity of the WTG installation to be the most likely type of
response. Any potential PTS and TTS would likely be concentrated at
half or one octave above the frequency band of pile driving noise (most
sound is below 2 kHz), which does not include the full predicted
hearing range of sei whales. Moreover, any TTS would be of a small
degree. Any avoidance of the LIA due to the Project's activities would
be expected to be temporary.
Given the magnitude and severity of the impacts discussed above
(including no more than three takes of the course of the 1-year IHA,
and a maximum allowable take by Level A harassment and Level B
harassment, of one and two, respectively), and in consideration of the
required mitigation and other information presented, Vineyard Wind's
activities are not expected to result in impacts on the reproduction or
survival of any individuals, much less affect annual rates of
recruitment or survival. For these reasons, we have determined that the
take by harassment anticipated and proposed to be authorized will have
a negligible impact on the Nova Scotia stock of sei whales.
Odontocetes
In this section, we include information here that applies to all of
the odontocete species and stocks addressed below. Odontocetes include
dolphins, porpoises, and all other whales possessing teeth and we
further divide them into the following subsections: sperm whales,
dolphins and small whales, and harbor porpoises. These sub-sections
include more specific information, as well as conclusions for each
stock represented.
No serious injury or mortality is anticipated or proposed to be
authorized. We anticipate that, given
[[Page 31061]]
ranges of individuals (i.e., that some individuals remain within a
small area for some period of time) and non-migratory nature of some
odontocetes in general (especially as compared to mysticetes), a larger
subset of these takes are more likely to represent multiple exposures
of some number of individuals than is the case for mysticetes, though
some takes may also represent one-time exposures of an individual.
While we expect animals to avoid the area during foundation
installation, their habitat range is extensive compared to the area
ensonified during these activities. As such, NMFS expects any avoidance
behavior to be limited to the area near the sound source.
As described earlier, Level B harassment may include direct
disruptions in behavioral patterns (e.g., avoidance, changes in feeding
or vocalizations), as well as those associated with stress responses or
TTS. While masking could also occur during foundation installation, it
would only occur in the vicinity of and during the duration of the
activity, and would not generally occur in a frequency range that
overlaps most odontocete communication or any echolocation signals. The
proposed mitigation measures (e.g., use of sound attenuation systems,
implementation of clearance and shutdown zones) would also minimize
received levels such that the expected severity of any behavioral
response would be less than exposure to unmitigated noise exposure.
Any masking or TTS effects are anticipated to be of low severity.
First, while the frequency range of pile driving falls within a portion
of the frequency range of most odontocete vocalizations, odontocete
vocalizations span a much wider range than the low frequency
construction activities planned for the project. Also, as described
above, recent studies suggest odontocetes have a mechanism to self-
mitigate the impacts of noise exposure (i.e., reduce hearing
sensitivity), which could potentially reduce TTS impacts. Any masking
or TTS is anticipated to be limited and would typically only interfere
with communication within a portion of an odontocete's range and as
discussed earlier, the effects would only be expected to be of a short
duration and for TTS, a relatively small degree. Furthermore,
odontocete echolocation occurs predominantly at frequencies
significantly higher than low frequency construction activities.
Therefore, there is little likelihood that threshold shift would
interfere with feeding behaviors.
The waters off the coast of Massachusetts are used by several
odontocete species. However, none except the sperm whale are listed
under the ESA and there are no known habitats of particular importance.
In general, odontocete habitat ranges are far-reaching along the
Atlantic coast of the U.S. and the waters off of New England, including
the LIA, do not contain any particularly unique odontocete habitat
features.
Sperm Whale
Sperm whales are listed as endangered under the ESA, and the North
Atlantic stock is considered both depleted and strategic under the
MMPA. The North Atlantic stock spans the east coast out into oceanic
waters well beyond the U.S. EEZ. Although listed as endangered, the
primary threat faced by the sperm whale across its range (i.e.,
commercial whaling) has been eliminated. Current potential threats to
the species globally include vessel strikes, entanglement in fishing
gear, anthropogenic noise, exposure to contaminants, climate change,
and marine debris. There is no currently reported trend for the stock
and although the species is listed as endangered under the ESA, there
are no current related issues or events associated with the status of
the stock that cause particular concern (e.g., no UMEs). There are no
known areas of biological importance (e.g., critical habitat or BIAs)
in or near the LIA. No mortality or serious injury is anticipated or
proposed to be authorized for this species.
The IHA would authorize up to two takes by Level B harassment over
the 1-year period, which equates to approximately 0.05 percent of the
stock abundance. If sperm whales are present in the LIA during any
Project activities, they will likely be only transient visitors,
although foraging and social behavior may occur in the shallow waters
off SNE (Westell et al., 2024). However, the potential for TTS is low
for reasons described in the general Odontocete section. If it does
occur, any hearing shift would be small and of a short duration.
Because foraging is expected to be rare in the LIA, TTS is not expected
to interfere with foraging behavior.
Given the magnitude and severity of the impacts discussed above
(including no more than two takes by Level B harassment over the course
of the 1-year IHA, and in consideration of the required mitigation and
other information presented, Vineyard Wind's activities are not
expected to result in impacts on the reproduction or survival of any
individuals, much less affect annual rates of recruitment or survival.
For these reasons, we have determined that the take by Level B
harassment anticipated and proposed to be authorized will have a
negligible impact on the North Atlantic stock of sperm whales.
Dolphins and Small Whales (Including Delphinids)
The five species and stocks included in this group (which are
indicated in table 3 in the Delphinidae family) are not listed under
the ESA, and nor are they listed as depleted or strategic under the
MMPA. There are no known areas of specific biological importance in or
around the LIA. As described above for any of these species and no UMEs
have been designated for any of these species. No serious injury or
mortality is anticipated or proposed to be authorized for these
species.
The five delphinid species (constituting five stocks) with takes
proposed to be authorized for the Project are Atlantic white-sided
dolphin, bottlenose dolphin, long-finned pilot whale, Risso's dolphin,
and common dolphin. The IHA would allow for the total authorization of
3 to 462 takes (depending on species) by Level B harassment, over the
1-year period. Overall, this annual take equates to approximately 0.01
(Risso's dolphin) to up to 0.27 (common dolphin) percent of the stock
abundance (if each take were considered to be of a different
individual, which is not likely the case), depending on the species.
The number of takes, likely movement patterns of the affected
species, and the intensity of any Level B harassment, combined with the
availability of alternate nearby foraging habitat suggests that the
likely impacts would not impact the reproduction or survival of any
individuals. While delphinids may be taken on several occasions, none
of these species are known to have small home ranges within the LIA or
known to be particularly sensitive to anthropogenic noise. Some TTS can
occur, but it would be limited to the frequency ranges of the activity
and any loss of hearing sensitivity is anticipated to return to pre-
exposure conditions shortly after the animals move away from the source
or the source ceases.
Across these species, the maximum number of incidental takes, by
Level B harassment (no Level A harassment is anticipated or proposed to
be authorized), proposed to be authorized ranges between 3 (Risso's
dolphin) to 462 (common dolphin). Though the estimated numbers of take
are comparatively higher than the numbers for mysticetes, we note that
for all
[[Page 31062]]
species they are relatively low relative to the population abundance.
As described above for odontocetes broadly, given the number of
estimated takes for some species and the behavioral patterns of
odontocetes, we anticipate that some of these instances of take in a
day represent multiple exposures of a smaller number of individuals,
meaning the actual number of individuals taken is lower. Although some
amount of repeated exposure to some individuals across a few days
within the year is likely, the intensity of any Level B harassment
combined with the availability of alternate nearby foraging habitat
suggests that the likely impacts would not impact the reproduction or
survival of any individuals.
Overall, the populations of all delphinid and small whale species
and stocks for which we proposed to authorize take are stable (no
declining population trends). None of these stocks are experiencing
existing UMEs. No mortality, serious injury, or Level A harassment is
anticipated or proposed to be authorized for any of these species.
Given the magnitude and severity of the impacts discussed above and in
consideration of the required mitigation and other information
presented, as well as the status of these stocks, the specified
activities are not expected to result in impacts on the reproduction or
survival of any individuals, much less affect annual rates of
recruitment or survival. For these reasons, we have determined that the
take by harassment anticipated and proposed to be authorized will have
a negligible impact on all of the following species and stocks:
Atlantic white-sided dolphins, bottlenose dolphins, long-finned pilot
whales, Risso's dolphins, and common dolphins.
Harbor Porpoise
Harbor porpoises are not listed as threatened or endangered under
the ESA, and the Gulf of Maine/Bay of Fundy stock is neither considered
depleted or strategic under the MMPA. The stock is found predominantly
in northern United States coastal waters (less than 150 m depth) and up
into Canada's Bay of Fundy (between New Brunswick and Nova Scotia).
Although the population trend is not known, there are no UMEs or other
factors that cause particular concern for this stock. No mortality or
non-auditory injury are anticipated or proposed to be authorized for
this stock.
The IHA would authorize up to 113 takes, by harassment only. The
maximum allowable take by Level A harassment and Level B harassment
would be 3 and 110, respectively (combined, this annual take (n=113)
which equates to approximately 0.19 percent of the stock abundance, if
each take were considered to be of a different individual). Given the
number of takes, while many of the takes likely represent exposures of
different individuals on 1 day a year, some subset of the individuals
exposed could be taken up to a few times annually.
Regarding the severity of takes by Level A harassment and Level B
harassment, because harbor porpoises are particularly sensitive to
noise, it is likely that a fair number of the responses could be of a
moderate nature, particularly to foundation installation. In response
to foundation installation, harbor porpoises are likely to avoid the
area during construction, as previously demonstrated in Tougaard et al.
(2009) in Denmark, in Dahne et al. (2013) in Germany, and in Vallejo et
al. (2017) in the United Kingdom, although a study by Graham et al.
(2019) may indicate that the avoidance distance could decrease over
time. However, foundation installation is scheduled to occur off the
coast of Massachusetts and given alternative foraging areas, any
avoidance of the area by individuals is not likely to impact the
reproduction or survival of any individuals.
With respect to PTS and TTS, the effects on an individual are
likely relatively low, given the frequency bands of pile driving (most
energy below 2 kHz) compared to harbor porpoise hearing (150 Hz to 160
kHz, peaking around 40 kHz). Specifically, TTS is unlikely to impact
hearing ability in their more sensitive hearing ranges or the
frequencies in which they communicate and echolocate. We expect any PTS
that may occur to be within the very low end of their hearing range
where harbor porpoises are not particularly sensitive and any PTS would
be of small magnitude. As such, any PTS would not interfere with key
foraging or reproductive strategies necessary for reproduction or
survival.
As discussed in Hayes et al. (2022), harbor porpoises are
seasonally distributed. During fall (October through November) and
spring (April through June), harbor porpoises are widely dispersed from
New Jersey to Maine with lower densities farther north and south.
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. In non-summer months they have been seen from the coastline to
deep waters (>1800 m; Westgate et al., 1998), although the majority are
found over the continental shelf. While harbor porpoises are likely to
avoid the area during any of the project's construction activities, as
demonstrated during European wind farm construction, the time of year
in which most work would occur is when harbor porpoises are not in
highest abundance, and any work that does occur would not result in the
species' abandonment of the waters off of Massachusetts.
Given the magnitude and severity of the impacts discussed above,
and in consideration of the required mitigation and other information
presented, the specified activities are not expected to result in
impacts on the reproduction or survival of any individuals, much less
affect annual rates of recruitment or survival. For these reasons, we
have determined that the take by harassment anticipated and proposed to
be authorized will have a negligible impact on the Gulf of Maine/Bay of
Fundy stock of harbor porpoises.
Phocids (Harbor Seals and Gray Seals)
The harbor seal and gray seal are not listed under the ESA, and
neither the western North Atlantic stock of gray seal nor the western
North Atlantic stock of harbor seal are considered depleted or
strategic under the MMPA. There are no known areas of specific
biological importance in or around the LIA. As described in the
Description of Marine Mammals in the Area of Specified Activities
section, a UME has been designated for harbor seals and gray seals and
is described further below. No serious injury or mortality is
anticipated or proposed to be authorized for this species.
For the 2 seal species, the IHA would authorize up to between 30
(harbor seals) and 241 (gray seals) takes, by harassment only. The
maximum allowable take for harbor seals by Level A harassment and Level
B harassment would be 1 and 29, respectively (combined, this take
(n=30) equates to approximately 0.05 percent of the stock abundance, if
each take were considered to be of a different individual). No takes by
Level A harassment are anticipated or proposed to be authorized for
gray seals. The maximum allowable take for gray seals by Level B
harassment (241) equates to approximately 0.88 percent of the stock
abundance, if each take were considered to be of a different
individual). Though gray seals and harbor seals are considered
migratory and no specific feeding areas have been defined for the area,
while some of the takes likely represent exposures of different
individuals on 1 day a year, it is likely that some subset of the
[[Page 31063]]
individuals exposed could be taken a few times annually.
Harbor and gray seals occur in SNE waters most often from December
through April. Seals are more likely to be close to shore, such that
exposure to foundation installation would be expected to be at low
levels. Known haulouts for seals occur along the shores of
Massachusetts.
As described in the Potential Effects to Marine Mammals and Their
Habitat section, construction of wind farms in Europe resulted in
pinnipeds temporarily avoiding construction areas but returning within
short time frames after construction was complete (Carroll et al.,
2010; Hamre et al., 2011; Hastie et al., 2015; Russell et al., 2016;
Brasseur et al., 2012). Effects on pinnipeds that are taken by Level B
harassment in the LIA would likely be limited to avoidance of the area
reactions such as increased swimming speeds, increased surfacing time,
or decreased foraging (if such activity were occurring). Most likely,
individuals would simply move away from the sound source and be
temporarily displaced from those areas (Lucke et al., 2006; Edren et
al., 2010; Skeate et al., 2012; Russell et al., 2016). Given the low
anticipated magnitude of impacts from any given exposure (e.g.,
temporary avoidance), even repeated Level B harassment across a few
days of some small subset of individuals, which could occur, is
unlikely to result in impacts on the reproduction or survival of any
individuals. Moreover, pinnipeds would benefit from the mitigation
measures described in the Proposed Mitigation section.
As described above, noise from pile driving is mainly low
frequency, and while any PTS and TTS that does occur would fall within
the lower end of pinniped hearing ranges (50 Hz to 86 kHz), PTS and TTS
would not occur at frequencies around 5 kHz where pinniped hearing is
most susceptible to noise-induced hearing loss (Kastelein et al.,
2018). In summary, any PTS and TTS would be of small degree and not
occur across the entire, or even most sensitive, hearing range. Hence,
any impacts from PTS and TTS are likely to be of low severity and not
interfere with behaviors critical to reproduction or survival.
Elevated numbers of harbor seal and gray seal mortalities were
first observed in July 2018 and occurred across Maine, New Hampshire,
and Massachusetts until 2020. Based on tests conducted so far, the main
pathogen found in the seals belonging to that UME was phocine distemper
virus, although additional testing to identify other factors that may
be involved in this UME are underway. In 2022, a pinniped UME occurred
in Maine with some harbor and gray seals testing positive for highly
pathogenic avian influenza (HPAI) H5N1. Neither UME (alone or in
combination) provides cause for concern regarding population-level
impacts to any of these stocks. For harbor seals, the population
abundance is over 61,000 and annual mortality/serious injury (M/SI)
(n=339) is well below PBR (1,729) (Hayes et al., 2023). The population
abundance for gray seals in the United States is over 27,000, with an
estimated overall abundance, including seals in Canada, of
approximately 366,400 (Hayes et al., 2023). In addition, the abundance
of gray seals is likely increasing in the U.S. Atlantic, as well as in
Canada (Hayes et al., 2023).
Given the magnitude and severity of the impacts of the Vineyard
Wind Project discussed above, and in consideration of the required
mitigation and other information presented, Vineyard Wind's activities
are not expected to result in impacts on the reproduction or survival
of any individuals, much less affect annual rates of recruitment or
survival. For these reasons, we have determined that the take by
harassment anticipated and proposed to be authorized will have a
negligible impact on harbor and gray seals.
Negligible Impact Determination
No mortality or serious injury is anticipated to occur or proposed
to be authorized. As described in the analysis above, the impacts
resulting from the project's activities cannot be reasonably expected
to, and are not reasonably likely to, adversely affect any of the
species or stocks through effects on annual rates of recruitment or
survival. Based on the analysis contained herein of the likely effects
of the specified activity on marine mammals and their habitat, and,
taking into consideration the implementation of the proposed mitigation
and monitoring measures, NMFS preliminarily finds that the marine
mammal take from the proposed activities would have a negligible impact
on all affected marine mammal species or stocks.
Small Numbers
As noted previously, only incidental take of small numbers of
marine mammals 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. When the
predicted number of individuals to be taken is fewer than one-third of
the species or stock abundance, the take is considered to be of small
numbers. Additionally, other qualitative factors may be considered in
the analysis, such as the temporal or spatial scale of the activities.
NMFS is authorizing incidental take by Level A harassment and/or
Level B harassment of 14 species of marine mammals (with 14 managed
stocks). The estimated number of instances of takes by combined Level A
harassment and Level B harassment relative to the best available
population abundance is less than one-third for all affected species
and stocks. For 13 stocks, 1 percent or less of the stock abundance is
proposed for take by harassment. Specific to the NARW, the estimated
amount of take, which is by Level B harassment only (no Level A
harassment is anticipated or authorized), is seven, or 2.07 percent of
the stock abundance, assuming that each instance of take represents a
different individual. Please see table 3 for information relating to
this small numbers analysis.
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 would 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.
Endangered Species Act
Section 7(a)(2) of the ESA 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
[[Page 31064]]
IHAs, NMFS consults internally whenever we propose to authorize take
for endangered or threatened species, in this case with NOAA GARFO.
There are four marine mammal species under NMFS jurisdiction that
are listed as endangered or threatened under the ESA that may taken, by
harassment, incidental to construction of the project: the North
Atlantic right, sei, fin, and sperm whale. NMFS issued a Biological
Opinion on September 11, 2020, concluding that the issuance of the 2023
Vineyard Wind IHA is not likely to jeopardize the continued existence
of threatened and endangered species under NMFS' jurisdiction and is
not likely to result in the destruction or adverse modification of
designated or proposed critical habitat. The Biological Opinion is
available at https://repository.library.noaa.gov/view/noaa/37556.
The Permit and Conservation Division requested re-initiation of
section 7 consultation with GARFO on the issuance of the Vineyard Wind
proposed IHA for Phase 2 of the Vineyard Wind Offshore Wind Project.
NMFS will conclude the ESA 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 impact pile driving of
monopiles in the Vineyard Wind Offshore Wind Farm offshore of
Massachusetts, 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/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable.
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 pile
driving activities. Please include with your comments any supporting
data or literature citations to help inform decisions on the request
for this IHA.
Dated: April 15, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2024-08434 Filed 4-22-24; 8:45 am]
BILLING CODE 3510-22-P