[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
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                                                                              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.

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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.

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