Proposed Rule2023-11814
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the New England Wind Project Offshore Massachusetts
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
June 8, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Park City Wind, LLC (Park City Wind) for Incidental Take Regulations (ITR) and an associated Letter of Authorization (LOA) pursuant to the Marine Mammal Protection Act (MMPA). The requested regulations would govern the authorization of take, by Level A harassment and/or Level B harassment, of small numbers of marine mammals over the course of 5 years (2025-2030) incidental to construction of the New England Wind Project. Park City Wind proposes to develop the New England Wind Project in two phases, known as Park City Wind (Phase 1) and Commonwealth Wind (Phase 2). Project activities that may result in incidental take include pile driving (impact and vibratory), drilling, unexploded ordnance or munitions and explosives of concern (UXO/MEC) detonation, and vessel-based site assessment surveys using high-resolution geophysical (HRG) equipment. NMFS requests comments on this proposed rule. NMFS will consider public comments prior to making any final decision on the promulgation of the requested ITR and issuance of the LOA; agency responses to public comments will be summarized in the final rule, if issued. If adopted, the proposed regulations would be effective March 27, 2025, through March 26, 2030.
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[Federal Register Volume 88, Number 110 (Thursday, June 8, 2023)]
[Proposed Rules]
[Pages 37606-37702]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-11814]
[[Page 37605]]
Vol. 88
Thursday,
No. 110
June 8, 2023
Part II
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 217
Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to the New England Wind Project Offshore
Massachusetts; Proposed Rule
Federal Register / Vol. 88 , No. 110 / Thursday, June 8, 2023 /
Proposed Rules
[[Page 37606]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 230530-0140]
RIN 0648-BL96
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the New England Wind Project
Offshore Massachusetts
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; proposed letter of authorization; request for
comments.
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SUMMARY: NMFS has received a request from Park City Wind, LLC (Park
City Wind) for Incidental Take Regulations (ITR) and an associated
Letter of Authorization (LOA) pursuant to the Marine Mammal Protection
Act (MMPA). The requested regulations would govern the authorization of
take, by Level A harassment and/or Level B harassment, of small numbers
of marine mammals over the course of 5 years (2025-2030) incidental to
construction of the New England Wind Project. Park City Wind proposes
to develop the New England Wind Project in two phases, known as Park
City Wind (Phase 1) and Commonwealth Wind (Phase 2). Project activities
that may result in incidental take include pile driving (impact and
vibratory), drilling, unexploded ordnance or munitions and explosives
of concern (UXO/MEC) detonation, and vessel-based site assessment
surveys using high-resolution geophysical (HRG) equipment. NMFS
requests comments on this proposed rule. NMFS will consider public
comments prior to making any final decision on the promulgation of the
requested ITR and issuance of the LOA; agency responses to public
comments will be summarized in the final rule, if issued. If adopted,
the proposed regulations would be effective March 27, 2025, through
March 26, 2030.
DATES: Comments and information must be received no later than July 10,
2023.
ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to <a href="http://www.regulations.gov">www.regulations.gov</a> and enter NOAA-NMFS-2023-
0080 in the Search box. Click on the ``Comment'' icon, complete the
required fields, and enter or attach your comments.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
<a href="http://www.regulations.gov">www.regulations.gov</a> without change. All personal identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
Attachments to electronic comments will be accepted in Microsoft Word,
Excel, or Adobe PDF file formats only.
FOR FURTHER INFORMATION CONTACT: Jaclyn Daly, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of Park City Wind's Incidental Take Authorization (ITA)
application and supporting documents, as well as a list of the
references cited in this document, may be obtained online at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable</a>. In case of
problems accessing these documents, please call the contact listed
above (see FOR FURTHER INFORMATION CONTACT).
Purpose and Need for Regulatory Action
This proposed rule would provide a framework under the authority of
the MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of
take of marine mammals incidental to construction of the New England
Wind Project within the Bureau of Ocean Energy Management (BOEM)
Renewable Energy Lease Area OCS-A 0534, the southwest (SW) portion of
Lease Area OCS-A 0501, and along an export cable corridor to a landfall
location in Massachusetts. NMFS received a request from Park City Wind
for 5-year regulations and an LOA that would authorize take, by Level A
harassment and/or Level B harassment, of 39 species of marine mammals
incidental to Park City Wind's construction activities. After reviewing
the request, NMFS is proposing to authorize the take, by harassment
only, of 38 species, representing 38 stocks. No mortality or serious
injury is anticipated or proposed for authorization. Please see the
Estimated Take of Marine Mammals section below for definitions of
relevant terms.
Legal Authority for the Proposed Action
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, regulations are
promulgated, and public notice and an opportunity for public comment
are provided.
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 as ``mitigation'');
and requirements pertaining to the mitigation, monitoring and reporting
of the takings are set forth.
As noted above, no serious injury or mortality is anticipated or
proposed for authorization in this proposed rule. Relevant definitions
of MMPA statutory and regulatory terms are included below:
<bullet> Citizen--individual U.S. citizens or any corporation or
similar entity if it is organized under the laws of the United States
or any governmental unit defined in 16 U.S.C. 1362(13) (see 50 CFR
216.103);
<bullet> Take--to harass, hunt, capture, or kill, or attempt to
harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362);
<bullet> Incidental taking--an accidental taking. This does not
mean that the taking is unexpected, but rather it includes those
takings that are infrequent, unavoidable or accidental (see 50 CFR
216.103);
<bullet> Serious Injury--any injury that will likely result in
mortality (50 CFR 216.3);
<bullet> Level A harassment--any act of pursuit, torment, or
annoyance which has the potential to injure a marine mammal or marine
mammal stock in the wild (16 U.S.C. 1362; 50 CFR 216.3); and
<bullet> Level B harassment--any act of pursuit, torment, or
annoyance which
[[Page 37607]]
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 (16 U.S.C. 1362).
Section 101(a)(5)(A) of the MMPA and the implementing regulations
at 50 CFR part 216, subpart I provide the legal basis for proposing
and, if appropriate, issuing 5-year regulations and an associated LOA.
This proposed rule also establishes required mitigation, monitoring,
and reporting requirements for Park City Wind's activities.
Summary of Major Provisions Within the Proposed Action
The major provisions within this proposed rule are as follows:
<bullet> Authorize take of marine mammals by Level A harassment
and/or Level B harassment.
<bullet> No mortality or serious injury of any marine mammal is
proposed to be authorized;
<bullet> Establish a seasonal moratorium on foundation installation
and UXO/MEC detonations during the months of highest North Atlantic
right whale (Eubalaena glacialis) presence in the project area (no
foundation installation or UXO/MEC detonation from January 1-April 30;
no vibratory pile driving in May and December; impact pile driving and
drilling activities would not be planned or occur in December unless
due to unforeseen circumstances and only with NMFS' approval; UXO/MEC
detonations would not be planned or occur in December or May unless due
to unforeseen circumstances and only with NMFS' approval);
<bullet> Enhanced North Atlantic right whale clearance, shutdown
and restart procedures May 1 through May 14 and November 1 through
December 31 (if a seasonally-restricted activity is approved in
December due to unforeseen circumstances);
<bullet> Require both visual and passive acoustic monitoring by
trained, NOAA Fisheries-approved Protected Species Observers (PSOs) and
Passive Acoustic Monitoring (PAM; where required) operators before,
during, and after select activities;
<bullet> Require the use of sound attenuation device(s) during all
foundation installation activities and UXO/MEC detonations to reduce
noise levels;
<bullet> Delay the start of foundation installation and UXO/MEC
detonations if a North Atlantic right whale is observed at any distance
by PSOs or acoustically detected within certain distances;
<bullet> Delay the start of foundation installation and UXO/MEC
detonations if other marine mammals are observed entering or within
their respective clearance zones;
<bullet> Shut down pile driving (if feasible) if a North Atlantic
right whale is observed or if other marine mammals enter their
respective shut down zones;
<bullet> Implement sound field verification requirements during
impact pile driving and UXO/MEC detonations to measure in situ noise
levels for comparison against the model results;
<bullet> Implement soft-starts for impact pile driving and use the
least hammer energy possible;
<bullet> Require PSOs to continue to monitor for the presence of
marine mammals for 30 minutes after any impact pile driving occurs;
<bullet> Implement ramp-up for HRG site characterization survey
equipment;
<bullet> Increase awareness of North Atlantic right whale presence
through monitoring of the appropriate networks and Channel 16, as well
as reporting any sightings to the sighting network;
<bullet> Implement various vessel strike avoidance measures;
<bullet> Implement Best Management Practices (BMPs) during
fisheries monitoring surveys, such as removing gear from the water if
marine mammals are considered at-risk or are interacting with gear; and
<bullet> Require frequent scheduled and situational reporting
including, but not limited to, information regarding activities
occurring, marine mammal observations and acoustic detections, and
sound field verification monitoring results.
Under Section 105(a)(1) of the MMPA, failure to comply with these
requirements or any other requirements in a regulation or permit
implementing the MMPA may result in civil monetary penalties. Pursuant
to 50 CFR 216.106, violations may also result in suspension or
withdrawal of the Letter of Authorization (LOA) for the project.
Knowing violations may result in criminal penalties under Section
105(b) of the MMPA.
National Environmental Policy Act (NEPA)
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate the proposed action (i.e., promulgation of
regulations and subsequent issuance of a 5-year LOA) and alternatives
with respect to potential impacts on the human environment.
Accordingly, NMFS proposes to adopt the BOEM's Environmental Impact
Statement (EIS), provided our independent evaluation of the document
finds that it includes adequate information analyzing the effects of
promulgating the proposed regulations and LOA issuance on the human
environment. NMFS is a cooperating agency on BOEM's EIS. BOEM's draft
EIS, ``New England Wind Draft Environmental Impact Statement (DEIS) for
Commercial Wind Lease OCS-A0534'', was made available for public
comment on December 23, 2022 (87 FR 78993), beginning the 60-day
comment period ending on February 21, 2023. Additionally, BOEM held
three virtual public hearings on January 27, February 1, and February
6, 2023.
Information contained within Park City Wind's incidental take
authorization (ITA) application and this Federal Register document
provide the environmental information related to these proposed
regulations and associated 5-year LOA for public review and comment.
NMFS will review all comments submitted in response to this notice of
proposed rulemaking prior to concluding the NEPA process or making a
final decision on the requested 5-year ITR and LOA.
Fixing America's Surface Transportation Act (FAST-41)
This project is covered under Title 41 of the Fixing America's
Surface Transportation Act, or ``FAST-41''. FAST-41 includes a suite of
provisions designed to expedite the environmental review for covered
infrastructure projects, including enhanced interagency coordination as
well as milestone tracking on the public-facing Permitting Dashboard.
FAST-41 also places a 2-year limitations period on any judicial claim
that challenges the validity of a Federal agency decision to issue or
deny an authorization for a FAST-41 covered project. 42 U.S.C. 4370m-
6(a)(1)(A).
Park City Wind's proposed project is listed on the Permitting
Dashboard, where milestones and schedules related to the environmental
review and permitting for the project can be found at <a href="https://www.permits.performance.gov/permitting-project/new-england-wind">https://www.permits.performance.gov/permitting-project/new-england-wind</a>.
Summary of Request
On December 1, 2021, Park City Wind, a limited liability company
registered in the State of Delaware and wholly owned subsidiary of
Avangrid Renewables, LLC, submitted a request for the promulgation of
regulations and issuance of an associated 5-year LOA to
[[Page 37608]]
take marine mammals incidental to construction activities associated
with implementation of the New England Wind Project (hereafter
``Project'') offshore of Massachusetts in the BOEM Lease Area OCS-A
0534 and the possible use of their southwest (SW) portion of Lease Area
OCS-A 0501. The request was for the incidental, but not intentional,
taking of a small number of 39 marine mammal species (comprising 38
stocks). Neither Park City Wind nor NMFS expects serious injury or
mortality to result from the specified activities nor is any proposed
for authorization.
Park City Wind is proposing to develop the Project in two phases
with a maximum of 132 wind turbine generators (WTGs) and electrical
service platforms (ESP) positions. Two positions may potentially have
co-located ESPs (i.e., two foundations installed at one grid position);
hence, the 132 foundations would be installed at 130 positions in the
lease area. Phase 1 would include 41 to 62 WTGs and 1 or 2 ESPs while
Phase 2 would include 64 to 88 WTG/ESP positions (up to 3 of those
positions will be occupied by ESPs). Four or five offshore export
cables will transmit electricity generated by the WTGs to onshore
transmission systems in the Town of Barnstable, Massachusetts.
In response to our questions and comments and following extensive
information exchange between Park City Wind and NMFS, Park City Wind
submitted a final revised application on July 13, 2022. NMFS deemed it
adequate and complete on July 20, 2022. This final application is
available on NMFS' website at <a href="https://www.fisheries.noaa.gov/protected-resource-regulations">https://www.fisheries.noaa.gov/protected-resource-regulations</a>.
On August 22, 2022, NMFS published a notice of receipt (NOR) of
Park City Wind's adequate and complete application in the Federal
Register (87 FR 51345), requesting public comments and information on
Park City Wind's request during a 30-day public comment period. During
the NOR public comment period, NMFS received comment letters from one
private citizen and one non-governmental organization (ALLCO Renewable
Energy Limited). NMFS has reviewed all submitted material and has taken
the material into consideration during the drafting of this proposed
rule. In January 2023 and again in March 2023, Park City Wind submitted
memos to NMFS detailing updates and changes to their ITA application
(``Application Update Report''). These are available on the NMFS
website at <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llc-construction-new-england-wind-offshore-wind">https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llc-construction-new-england-wind-offshore-wind</a>.
NMFS previously issued one Incidental Harassment Authorization
(IHA) to Park City Wind for the taking of marine mammals incidental to
marine site characterization surveys, using high-resolution geophysical
(HRG) of the Project Phase 1 in the BOEM Lease Area OCS-A 0534 (87 FR
44087, July 07, 2022). NMFS has also previously issued another IHA to
Avangrid Renewables, LLC (Avangrid), owner of Park City Wind, LLC, to
take small numbers of marine mammals incidental to an HRG survey for a
BOEM Lease Area (OCS-A 0508) off the coasts of North Carolina and
Virginia (84 FR 31032, June 28, 2019). To date, Park City Wind and
Avangrid have complied with all IHA requirements (e.g., mitigation,
monitoring, and reporting). Applicable monitoring results may be found
in the Estimated Take of Marine Mammals section. If available, the full
monitoring reports can be found on NMFS' website at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable</a>.
On August 1, 2022, NMFS announced proposed changes to the existing
North Atlantic right whale vessel speed regulations (87 FR 46921,
August 1, 2022) 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 an ongoing Unusual Mortality Event. Should a final vessel speed rule
be issued and become effective during the effective period of this ITR
(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. The responsibility to comply with the applicable
requirements of any vessel speed rule would become effective
immediately upon the effective date of any final vessel speed rule and,
when notice is published on the effective date, NMFS would also notify
Park City Wind if the measures in the speed rule were to supersede any
of the measures in the MMPA authorization such that they were no longer
required.
Description of the Specified Activities
Overview
Park City Wind has proposed to construct and operate a wind energy
facility in State and Federal waters in the Atlantic Ocean in lease
area OCS-A 0534. This lease area is located within the Massachusetts
Wind Energy Area (MA WEA) and adjacent to the Rhode Island/
Massachusetts Wind Energy Area (RI/MA WEA). The Project will occupy all
of Lease Area OCS-A 0534 and potentially a portion of Lease Area OCS-A
0501 in the event that Vineyard Wind 1 does not develop spare or extra
positions included in Lease Area OCS-A 0501. If Vineyard Wind 1 does
not develop spare or extra positions in Lease Area OCS-A 0501, those
positions would be assigned to Lease Area OCS-A 0534. Accordingly, for
the purposes of the LOA, Park City Wind has defined the Southern Wind
Development Area (SWDA) as all of Lease Area OCS-A 0534 and the
southwest portion of Lease Area OCS-A 0501.
The Project would consist of several different types of permanent
offshore infrastructure, including wind turbine generators (WTGs) and
associated foundations, ESPs, and offshore cabling. Onshore cabling,
substations, and operations and maintenance (O&M) facilities are also
planned. The Project is divided into two phases: Park City Wind (Phase
1) and Commonwealth Wind (Phase 2). Phase 1 would occupy 150-231 km\2\
(37,066-57,081 acres) which would include 41-62 WTGs and 1-2 ESPs.
Phase 1 includes two WTG foundation types: monopiles and piled jackets.
The ESP(s) will also be supported by a monopile or jacket foundation.
Strings of WTGs will connect with the ESP(s) via a submarine inter-
array cable transmission system. Two high-voltage alternating current
(HVAC) offshore export cables, up to 101 km (62.8 mi) in length per
cable, would be installed within the SWDA. An Offshore Export Cable
Corridor (OECC) would transmit electricity from the ESP(s) to a
landfall site.
Phase 2 depends upon the final footprint of Phase 1. Phase 2 is
expected to contain 64 to 88 WTGs and 1-3 ESP positions within an area
ranging from 222-303 km\2\ (54,857-74,873 acres). Phase 2 includes
three general WTG foundation types: monopiles, jackets (with piles or
suction buckets), or bottom-frame foundations (with piles or suction
buckets). Inter-array cables will transmit electricity from the WTGs to
[[Page 37609]]
the ESP(s). The ESP(s) will also be supported by a monopile or jacket
foundation (with piles or suction buckets). Two or three HVAC offshore
export cables, each with a maximum length of 116-124 km (63-67 NM) per
cable, will transmit power from the ESP(s) to shore. All Phase 2
offshore export cables are planned to use the same OECC as the Phase 1.
Cables for Phase 1 and Phase 2 will diverge 2-3 km (1-2 mi) from shore
to unique landfall locations.
The installation of WTGs and ESPs, would require impact and
vibratory pile driving and drilling. Work would also include HRG
vessel-based site characterization surveys using active acoustic
sources with frequencies of less than 180 kHz and the potential
detonations of 10 unexploded ordnances or Munitions and Explosives of
Concern (UXO/MEC) of different charge weights. Additionally, project
plans include trenching, laying, and burial activities associated with
the installation of the export cable route from the ESP to the shore-
based landing locations and the inter-array cables between turbines;
site preparation work (e.g., boulder removal); placement of scour
protection around foundations; and several types of fishery and
ecological monitoring surveys. Vessels would transit within the project
area and between ports and the wind farm to transport crew, supplies,
and materials to support pile installation. All offshore cables will
connect to onshore export cables, substations, and grid connections,
which would be located in Barnstable County, Massachusetts. Marine
mammals exposed to elevated noise levels during impact and vibratory
pile driving, drilling, detonations of UXOs, or site characterization
surveys may be taken by Level A harassment and/or Level B harassment
depending on the specified activity. No serious injury or mortality is
anticipated or proposed for authorization.
Dates and Duration
Park City Wind anticipates that the Project activities with the
potential to result in harassment of marine mammals would occur
throughout all 5 years of the proposed regulations which, if
promulgated, would be effective from March 27, 2025 through March 26,
2030. The estimated schedule, including dates and duration, for various
activities is provided in Table 1 (also see Tables 1-3 in Application
Update Report). However, this proposed rule considers the potential for
activity schedules to shift. Detailed information about the activities
themselves may be found in the Detailed Description of the Specific
Activities subsection.
Table 1--Estimated Activity Schedule To Construct and Operate the
Project
------------------------------------------------------------------------
Project activity Estimated schedule Estimated duration
------------------------------------------------------------------------
HRG Surveys..................... Q1 2025-Q4 2029... Any time of the
year, up to 25
days per year.
Scour Protection Pre- or Post- Q1 2025-Q4 2029... Any time of the
Installation. year.
WTG and ESP Foundation Q2-Q4 2026 and Up to 8 months per
Installation, Schedule A. 2027 \1\. year.
WTG and ESP Foundation Q2-Q4 2026, 2027, Up to 8 months per
Installation, Schedule B. and 2028 \1\. year.
Horizontal Directional Drilling Q4 2025-Q2 2026... Up to 150 days.
at Cable Landfall Sites.
UXO/MEC Detonations............. Q2-Q4 2025 and Up to 6 days in
2026 \3\. 2025 and 4 days
in 2026. No more
than 10 days
total.
Inter-array Cable Installation.. Q3-Q4 2026 and Q2 Phase 1: 5 months;
2027-Q2 2028. \2\ Phase 2: 10
months.\2\
Export Cable Installation and Q2 2026-Q2 2028... Phase 1: 8-9
Termination. months; \1\ Phase
2: 13-17
months.\1\
Fishery Monitoring Surveys...... Q1 2025-Q4 2029... Any time of year.
---------------------------------------
Turbine Operation............... Initial turbines operational 2027, all
turbines operational by 2028.
------------------------------------------------------------------------
\1\ Foundation installation pile driving would be limited to May 1-
December 31, annually; however, pile driving in December will not be
planned but may occur due to unforeseen circumstances (e.g.,
unanticipated extended weather delays, unexpected technical
difficulties) and with NMFS approval.
\2\ The Project is divided into 2 phases: Park City Wind (Phase 1) and
Commonwealth Wind (Phase 2).
\3\ Park City Wind requested UXO/MEC detonations be allowed Q1 2025-Q4
2026. We propose to only allow it May-December 2025 and 2026.
Specific Geographic Region
Park City Wind would construct the Project in Federal waters
offshore of Massachusetts (Figure 1). The project area is part of the
Rhode Island/Massachusetts Wind Energy Area (RI-MA WEA). The project
area covers approximately 101,590 acres (411 km\2\) in Lease Area OCS-A
0534. The project area is located about 20 miles (32 km) southwest of
Martha's Vineyard, about 24 miles (39 km) south of Nantucket, and
adjacent to the southwest boundary of the BOEM-approved Vineyard Wind 1
energy project (Lease Area OCS-A 0501; 65,296 acres (262 km\2\)
assigned for potential Project development). Water depths in the
project area range from 43 to 62 m (141-203 ft) and in the OECC range
from less than 2 m to 46 m (<7-151 ft). The onshore components of the
Project will include up to three export cable landfalls in Barnstable
County, Massachusetts (one for Phase 1 and up to two for Phase 2).
Park City 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 lease area and cable corridor
are 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. In the Mid-Atlantic Bight, which extends from Massachusetts to
North Carolina, the pattern of sediment distribution is relatively
simple. The continental shelf south of New England is broad and flat,
dominated by fine grained sediments. Most of the surficial sediments on
the continental shelf are sands and gravels. Silts and clays
predominate at and beyond the shelf edge, with most of the slope being
70-100 percent mud. Fine sediments are also common in the shelf valleys
leading to the submarine canyons, as well as in areas such as the ``Mud
Patch'' south of Rhode Island. There are some larger materials,
including boulders and rocks, left on the seabed by retreating
glaciers, along the
[[Page 37610]]
coast of Long Island and to the north and east.
In support of the Rhode Island Ocean Special Area Management Plan
development process, Codiga and Ullman (2011) reviewed and summarized
the physical oceanography of coastal waters off Rhode Island.
Conditions off the coast of Rhode Island are shaped by a complex
interplay among wind-driven variability, tidal processes, and density
gradients that arise from combined effects of interaction with adjacent
estuaries, solar heating, and heat flux through the air-sea interface.
In winter and fall, the stratification is minimal and circulation is a
weak upwelling pattern directed offshore at shallow depths and onshore
near the seafloor. In spring and summer, strong stratification develops
due to an important temperature contribution, and a system of more
distinct currents occurs, including a narrow flow that proceeds
counterclockwise around the perimeter of Rhode Island Sound (RIS)
likely in association with a tidal mixing front.
The waters in the vicinity of the Project are transitional waters
positioned between the continental slope and the coastal environments
of Rhode Island Sound and Nantucket Sound. The region is generally
characterized by predominantly mobile sandy substrate, and the
associated benthic communities are adopted to survive in a dynamic
environment. The WEAs are composed of a mix of soft and hard bottom
environments as defined by the dominant sediment grain size and
composition (Continental Margin Mapping Program [Department of the
Interior, 2020]; usSEABED (USGS, 2020)).
The benthic environment of the RI-MA WEA is dominated by sandy
sediments that ranged from very fine to medium sand; very fine sands
tend to be more prevalent in deeper, lower energy areas (i.e., the
southern portion of the MA WEA), whereas coarser sediments, including
gravels (e.g., patchy cobbles and boulders) were found in shallower
areas (Bay State Wind, 2019; Deepwater Wind South Fork, LLC, 2019; DWW
Rev I, LLC, 2020; Stokesbury, 2014; LaFrance et al., 2010; McMaster,
1960; Popper et al., 2014). The species that inhabit the benthic
habitats of the OCS are typically described as infaunal species, those
living in the sediments (e.g., polychaetes, amphipods, mollusks), and
epifaunal species, those living on the seafloor surface (mobile, e.g.,
sea starts, sand dollars, sand shrimp) or attached to substrates
(sessile, e.g., barnacles, anemones, tunicates). Further detail on the
benthic habitats found in the project area, including the results of
site-specific benthic habitat assessments, can be found within
Construction and Operations Plan (COP) Volume II-A, Section 5--Results
Of Biological Surveys and COP Volume II-A Appendices--Appendix II-H
2016-2020 Benthic Reports.
BILLING CODE 3510-22-P
[[Page 37611]]
[GRAPHIC] [TIFF OMITTED] TP08JN23.000
BILLING CODE 3510-22-C
Detailed Description of Specific Activities
Below, we provide detailed descriptions of Park City Wind's
activities, explicitly noting those that are anticipated to result in
the take of marine mammals and for which incidental take authorization
is requested. Additionally, a brief explanation is provided for those
activities that are not expected to result in the take of marine
mammals.
WTG and ESP Foundation Installation
Park City Wind proposes to install a maximum of 130 wind turbine
generator (WTG) and electrical service platform (ESP) positions. Two
positions may potentially have co-located ESPs (i.e., 1
[[Page 37612]]
WTG and 1 ESP foundation installed at 1 grid position), resulting in
132 foundations. The WTGs would have a maximum tip height of 357 m
(1,171 ft) and a maximum penetration depth of 85 m (279 ft). Each
turbine would be spaced 1 nautical mile (nmi) apart in fixed east-to-
west rows and north-to-south columns to create the 1 nmi by 1 nmi grid
arrangement. Park City Wind anticipates that the initial WTGs (41-62
WTGs) would become operational in 2027 after installation is completed
and all necessary components, such as array cables, ESPs, export cable
routes, and onshore substations. Park City Wind expects that all
remaining turbines will be operational by 2028. No more than one
foundation will be installed at a time (i.e., concurrent/simultaneous
pile driving of foundations would not occur).
Phase 1 will include 41 to 62 WTGs and 1 or 2 ESPs for a total of
42 to 64 foundations. The total number of foundations in Phase 2
depends upon the final footprint of Phase 1. Phase 2 is expected to
contain 64 to 88 WTG/ESP foundations (up to 3 of those positions will
be occupied by ESPs). While only 132 foundations would be permanently
installed, Park City Wind has accounted for up to 133 pile driving
events in its take request to account for the instance wherein
foundation installation began but is unable to be completed due to
environmental or engineering constraints and the pile is re-driven at
another position.
Phase 1 foundation types would be monopiles or jackets while Phase
2 foundation types include monopiles, jackets, or bottom-frame
foundations. Jacket foundations require the installation of three to
four jacket securing piles, known as pin piles. The bottom-frame
foundation is similar to a conventional jacket foundation, but
generally has fewer, larger structural tubular members, has a
triangular space frame, no small-diameter lattice cross-bracing, and a
single central vertical tubular column. At each foot, the structure
would be secured to the seafloor using driven piles similar to those
used by piled jacket foundations or suction buckets. For purposes of
this analysis, the use of suction buckets to secure bottom-frame
foundations is not being considered further in this analysis as
installation of bottom-frame foundations using suction buckets is not
anticipated to result in noise levels that would cause harassment to
marine mammals.
The applicant proposed two construction schedules, A and B.
Construction schedule A assumes a single 2-year construction scenario.
Overall, 89 monopile foundations and 2 jacket foundations (8 pin piles)
would be installed in 2026 over 52 days and 18 monopile foundations and
24 jacket foundations (96 pin piles) would be installed in 2027 over 35
days for a total of 87 days of pile driving to install all 133
foundations. All days would include impact pile driving and a subset
may include vibratory pile driving and drilling. No more than one
foundation would be installed at a time (i.e., concurrent/simultaneous
installation of more than one foundation would not occur). Park City
Wind anticipates that a maximum of two monopiles or one jacket (up to
four pin piles) is expected to be installed per day.
Construction schedule B assumes that all construction would occur
over a 3-year period (2026-2028). Overall, 55 monopile foundations and
3 jacket foundations (12 pin piles) would be installed in 2026 over 38
days, 53 jackets (212 piles) would be installed in 2027 over 53 days,
and 22 jackets (88 pin piles) would be installed over 22 days in 2028.
In total, 133 foundations would be installed over 113 days. Similar to
Schedule A, all days would include impact pile driving and a subset may
include vibratory pile driving and drilling. Please see Table 2 and 3
in Park City Wind's March 2023 Application Update Report. Table 2
provides a summary of Construction Schedule A and B.
Table 2--Foundation Installation Construction Schedules
[Days]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Schedule A Schedule B
Foundation type -------------------------------------------------------------------------------------------
2026 2027 Total 2026 2027 2028 Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monopiles................................................... 89 18 107 55 0 0 55
Jackets..................................................... 2 24 26 3 53 22 78
No. of Days................................................. 52 35 87 38 53 22 113
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monopiles would be up to 12 m (39.37 ft) or 13 m (42.7 ft) in
diameter and could be installed in both Phases 1 and 2. Jacket
foundations require up to four pin piles and each would have a maximum
diameter of 4 m (13.1 ft) diameter (see Figures 3-6 in the ITA
application). When accounting for pre-piling preparatory work and post-
piling activities, installation of a single monopile or jacket pile
will take approximately 6-13 hours. Park City Wind anticipates at least
1 hour between monopile installations and 30 minutes between jacket pin
pile installations. Park City Wind anticipates that a maximum of two
monopiles or one jacket (up to four pin piles) is expected to be
installed per day. Pile driving activities could occur within the 8-
month period of May through December.
A WTG monopile foundation typically consists of a single steel
tubular section with several sections of rolled steel plate welded
together and secured to the seabed. Secondary structures on each WTG
monopile foundation will include a boat landing or alternative means of
safe access, ladders, a crane, and other ancillary components. A
typical monopile installation sequence begins with the monopiles
transported directly to the project area for installation or to the
construction staging port by an installation vessel or a feeding barge.
At the foundation location, the main installation vessel upends the
monopile in a vertical position in the pile gripper mounted on the side
of the vessel. The hammer is then lifted on top of the pile and pile
driving commences with a soft-start and proceeds to completion. Piles
are driven until the target embedment depth is met (up to 50 m), then
the pile hammer is removed and the monopile is released from the pile
gripper. Once installation of the monopile is complete, the vessel
moves to the next installation location.
Monopiles would be installed using a 5,000 kJ to 6,000 kJ hammer to
a maximum penetration depth of 40 m (131 ft). Park City Wind estimates
that a monopile could require up to 6,970 strikes at up to 30.0 blows
per minute (bpm) to reach full penetration depth. It is expected that
each monopile installation will last less than 6 hours,
[[Page 37613]]
with most installations anticipated to last between 3-4 hours. Figures
3-6 in Park City Wind's ITA application provide a conceptual example of
the WTG support structures (i.e., towers and foundations). WTGs would
be designed to withstand severe weather conditions anticipated at the
SWDA (COP Appendix I-E). While major storms, winter nor'easters, and,
to a lesser extent, hurricanes pass through the SWDA regularly, the
Project's offshore facilities are designed to withstand such severe
weather events (COP Volume I).
Jacket foundations may be used. Once delivered to the SWDA, the
jacket will be lifted off the transport or installation vessel and
lowered to the seabed with the correct orientation. The piles will be
driven to the engineered depth, following the same process described
above for monopiles. The WTG jacket piles are expected to be pre-piled
(i.e., the jacket structure will be set on pre-installed piles). Up to
three ESP jackets are expected to be post-piled (i.e., the jacket is
placed on the seafloor and piles are subsequently driven through guides
at the base of each leg). For the ESP post-piled jackets, piling would
be initiated during daylight hours (no later than 1.5 hours prior to
civil sunset) and need to continue until all piles are installed due to
health and safety concerns.
Jacket foundations would be installed using a 3,500 kJ hammer
energy pile driving for a 4-m pin pile to reach their maximum
penetration depth of 50 m (164 ft). There are four pins per jacket
foundation, Park City Wind estimates that each pin will take up to
9,805 hammer strikes at up 30.0 bpm to reach full penetration depth
(Table 1 in the ITA application). Foundation installation would use a
20-minute soft-start to ensure that the monopile or jacket foundation
pile remains vertical and to allow any motile marine life to leave the
area before the pile driving intensity is increased. Jacket foundation
installation times will vary, but will likely take up to 6 hours per
pin pile, depending on whether the jacket is pre- or post-piled (Table
4 ITA application). The bottom-frame foundation (for Phase 2 only) is
similar to the jacket foundation, with shorter piles and shallower
penetration. The potential acoustic impact of the bottom-frame
foundation installation is equivalent to or less than that predicted
for the jacket foundation. As the design and installation methods for
bottom-frame foundations would be equivalent to or less than jacket
foundations, bottom-frame foundations are not carried forward in this
document.
During construction of the Project, it may be necessary to start
pile installation using a vibratory hammer rather than using an impact
hammer, a technique known as vibratory setting of piles. The vibratory
method is particularly useful when soft seabed sediments are not
sufficiently stiff to support the weight of the pile during the initial
installation, increasing the risk of `pile run' where a pile sinks
rapidly through seabed sediments. Piles which experience pile run can
be difficult to recover and pose significant safety risks to the
personnel and equipment on the construction vessel. The vibratory
hammer mitigates this risk by forming a hard connection to the pile
using hydraulic clamps, thereby acting as a lifting/handling tool as
well as a vibratory hammer. The tool is inserted into the pile on the
construction vessel deck, and the connection made. The pile is then
lifted, upended and lowered into position on the seabed using the
vessel crane. After the pile is lowered into position, vibratory pile
installation will commence. Vibratory pile installation is a technique
where piles are driven into soil using a longitudinal vibration motion.
The vibratory hammer installation method can continue until the pile is
inserted to a depth that is sufficient to fully support the structure,
and then the impact hammer can be positioned and operated to complete
the pile installation. Of the 132 WTG/ESPs, Park City Wind estimates
approximately 70 total foundations (53 percent) may require vibratory
hammering before impact hammering. Table 7 and 8 in Park City Wind's
application provides a breakdown of the number of potential days of
pile installation, by activity, per month under the maximum design
scenario for Schedules A and B, respectively.
Construction schedule A anticipates 20 days of vibratory hammering
in 2026 and 25 days in 2027 (total 45 days) (Table 2). Construction
schedule B anticipates 20 days of vibratory hammering in 2026, 25 days
in 2027, and 9 days in 2028 (total 54 days) (Table 2). Comparisons of
vibratory pile installation versus impulsive hammer pile installation
indicate that vibratory pile installation typically produces lower
amplitude sounds in the marine environment than impact hammer
installation (Rausche and Beim 2012). The average expected duration of
vibratory setting is approximately 30 minutes per pile for the Project.
Due to the small size of the permanent threshold shift (PTS) ranges and
the mitigation that will be applied during construction, no Level A
harassment is expected. More information on vibratory pile setting is
in Section 1.2.2 of the ITA application.
Drilling is a contingency measure that may be required to remove
soil and/or boulders from inside the pile in cases of pile refusal
during installation. A pile refusal can occur if the total frictional
resistance of the soil becomes too much for the structural integrity of
the pile and the capability of the impact hammer. Continuing to drive
in a refused condition can lead to overstress in the pile and potential
to buckle (tear) the pile material. The use of an offshore drill can
reduce the frictional resistance by removing the material from inside
the pile and allowing the continuation of safe pile driving. An
offshore drill is an equipment piece consisting of a motor and bottom
hole assembly (BHA). The drill is placed on top of the refused pile
using the construction vessel crane, and the BHA is lowered down to the
soil inside the pile. On the bottom face of the BHA is a traditional
``drill bit,'' which slowly rotates (at 4 or 5 revolutions per minute
or approximately 0.4 m per hour) and begins to disturb the material
inside the pile. As the disturbed material mixes with seawater which is
pumped into the pile, it begins to liquefy. The liquefied material is
pumped out to a pre-designated location, leaving only muddy seawater
inside the pile instead of a solid ``soil plug,'' and largely reducing
the frictional resistance generated by the material inside the pile.
When enough material has been removed from inside the pile and the
resistance has reduced sufficiently, the drill is then lifted off the
pile and recovered to the vessel. The impact hammer is then docked onto
the pile and impact pile driving commences. It may be necessary to
remove and replace the drill several times in the driving process to
achieve sufficiently low frictional resistance to achieve the design
penetration through impact pile driving. Of the 132 WTG/ESPs, Park City
Wind estimates 48 foundations (36 percent) may require drilling to
remove soil and/or boulders from inside the pile that would otherwise
affect the capability of the impact hammer. Construction schedule A
anticipates 33 days of drilling in 2026 and 15 days in 2027 (total 48
days) (Table 2). Construction schedule B anticipates 20 days of
drilling in 2026, 19 days in 2027, and 9 days in 2028 (total 48 days)
(Tables 2).
While pre-piling preparatory work and post-piling activities could
be ongoing at one foundation position as pile driving is occurring at
another position, there is no concurrent/
[[Page 37614]]
simultaneous pile driving of foundations planned (see Dates and
Duration section). Impact pile driving associated with foundation
installation would be limited to the months of May through December and
is currently scheduled to be conducted during 2026-2028 (depending
which construction schedule is done, A or B). Installation of
foundations is anticipated to result in the take of marine mammals due
to noise generated during pile driving.
Park City Wind has proposed to conduct pile driving 24 hours per
day. Once construction begins, Park City Wind would proceed as rapidly
as possible, while meeting all required mitigation and monitoring
measures, to reduce the total duration of construction. NMFS
acknowledges the benefits of completing construction quickly during
times when North Atlantic right whales are unlikely to be in the area
but also recognizes challenges associated with monitoring during
reduced visibility conditions such as night. Should Park City Wind
submit a NMFS-approved Alternative Monitoring Plan, pile driving may be
initiated at night. NMFS intends to condition the final rule, if
issued, identifying if initiating pile driving at night may occur.
Installation of the WTG and ESP foundations is anticipated to
result in the take of marine mammals due to noise generated during pile
driving and drilling.
HRG Surveys
High-resolution geophysical site characterization surveys would
occur annually throughout the 5 years the rule and LOA would be
effective with duration dependent on the activities occurring in that
year (i.e., construction versus non-construction year). HRG surveys
would utilize up to a maximum of three vessels working concurrently in
different sections of the Lease Area and OECC corridor. Park City Wind
estimates that no more than 3 years will have HRG surveys and each year
would have at least 6,000 km surveyed. In total, no more than 18,000 km
may be surveyed across the 5-years with a total of no more than 225
vessel days within the Lease Area and along the OECC corridor in water
depths ranging from 1 m (3.6 ft) to 61.9 m (203 ft). Each day that a
survey vessel covers 80 km (50 miles) of survey trackline is considered
vessel day. For example, three vessels operating concurrently on the
same calendar day, covering 80 km each, would be 3 vessel days.
HRG surveys would be conducted to identify any seabed debris and to
support micrositing of the WTG and ESP foundations and cable routes.
Geophysical survey instruments may include side scan sonar, synthetic
aperture sonar, single and multibeam echosounders, sub-bottom profilers
(SBP), and magnetometers/gradiometers, some of which are expected to
result in the take of marine mammals (LOA Section 1.2.5.). Equipment
may be mounted to the survey vessel or the Project may use autonomous
surface vehicles (SFV) to carry out this work. Surveys would occur
annually, with durations dependent on the activities occurring in that
year (i.e., construction years versus operational years).
As summarized previously, HRG surveys will be conducted using up to
three vessels concurrently. Up to 80 km of survey lines will be
surveyed per vessel each survey day at approximately 7.4 km/hour (4
knots) on a 24-hour basis. HRG surveys are anticipated to operate at
any time of year for 25 days per year, a maximum of 125 days for the
maximum of the 3 planned years covered under the 5-years of the LOA. Of
the HRG equipment types proposed for use, the following sources have
the potential to result in take of marine mammals:
<bullet> Medium penetration SBPs (boomers) to map deeper subsurface
stratigraphy as needed. A boomer is a broad-band sound source operating
in the 0.2 kHz to 15 kHz frequency range. This system is typically
mounted on a sled and towed behind the vessel.
<bullet> Medium penetration SBPs (sparkers) to map deeper
subsurface stratigraphy as needed. A sparker creates acoustic pulses
from 0.05 kHz to 3 kHz omni-directionally from the source that can
penetrate several hundred meters into the seafloor. These are typically
towed behind the vessel with adjacent hydrophone arrays to receive the
return signals.
Table 3 identifies all the representative survey equipment that
operate below 180 kilohertz (kHz) (i.e., at frequencies that are
audible and have the potential to disturb marine mammals) that may be
used in support of planned geophysical survey activities and are likely
to be detected by marine mammals given the source level, frequency, and
beamwidth of the equipment. Equipment with operating frequencies above
180 kHz and equipment that does not have an acoustic output (e.g.,
magnetometers) may also be used but are not discussed further because
they are outside the general hearing range of marine mammals likely to
occur in the project area. In addition, due to the characteristics of
non-impulsive sources (i.e., Ultra-Short BaseLine (USBL), Innomar, and
other parametric sub-bottom profilers), take is not anticipated due to
operating characteristics like very narrow beam width which limit
acoustic propagation. Therefore, no Level A harassment or B harassment
can be reasonably expected from the operation of these sources. The
sources that have the potential to result in harassment to marine
mammals include boomers and sparkers (Table 3).
Table 3--Summary of Representative HRG Survey Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Peak source
Representative Operating level (dB level 0-pk Pulse Repetition Beamwidth Information
Equipment type Name model frequency re 1 (dB re 1 duration rate (Hz) (degrees) source
(kHz) [mu]Pa m) [mu]Pa m) (ms)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Boomer............... Applied Acoustics Applied Acoustics 0.2-15 205 212 0.8 \e\ 2 180 CF
AA251. AA251 \a\.
Sparker.............. GeoMarine Geo SIG ELC 820 \c\ 0.05-3 203 213 3.4 \e\ 1 \d\ 180 CF
Spark 2000 (400 Sparker \b\.
tip).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Frequency estimated from Figures 14 and 16 in Crocker and Fratantonio (2016). Source levels, beam width, and pulse duration from Table 5 in Crocker
and Fratantonio (2016) at 300 J.
\b\ SIG ELC 820 has similar operation settings as Geo Spark 2000 (Sect. I.5.1). See Table 9 in Crocker and Fratantonio (2016) source for levels at 5 m
source depth, 750 J setting.
\c\ Frequency source specifications provided by Vineyard Wind.
\d\ Assumes omnidirectional source.
\e\ Vineyard Wind indicates they will use this repetition rate.
[[Page 37615]]
UXO/MEC Detonations
Park City Wind anticipates encountering UXO/MECs during Project
construction. UXO/MECs include explosive munitions (such as bombs,
shells, mines, torpedoes, etc.) that did not explode when they were
originally deployed or were intentionally discarded in offshore
munitions dump sites to avoid land-based detonations. The risk of
incidental detonation associated with conducting seabed-altering
activities, such as cable laying and foundation installation, in
proximity to UXO/MECs jeopardizes the health and safety of project
participants.
For UXO/MECs that are positively identified in proximity to planned
activities on the seabed, several alternative strategies will be
considered prior to in-situ UXO/MEC disposal. These may include: (1)
relocating the activity away from the UXO/MEC (avoidance), (2) physical
UXO/MEC removal (lift and shift), (3) alternative combustive removal
technique (low order disposal), (4) cutting the UXO/MEC open to
apportion large ammunition or deactivate fused munitions (cut and
capture), or (5) using shaped charges to ignite the explosive materials
and allow them to burn at a slow rate rather than detonate
instantaneously (deflagration). Only after these alternatives are
considered and found infeasible would in-situ high-order UXO/MEC
detonation be pursued. If detonation is necessary, detonation noise
could result in the take of marine mammals by Level A harassment and
Level B harassment.
Park City wind anticipates that up to 10 UXO/MECs may require
disposal through high-order detonation and that these detonations would
occur in 2025 and 2026. To better assess the likelihood of encountering
UXO/MECs during project construction, Park City Wind is conducting HRG
surveys to identify potential UXO/MECs that have not been previously
mapped. As these surveys and analysis of data from them are still
underway, the exact number and type of UXO/MECs in the project area are
not yet known. However, Park City Wind assumes that up to 10 UXO/MECs
charges, of up to 454-kg (1,000 pounds; lbs), which is the largest
charge that is reasonably expected to be encountered (See Estimated
Take of Marine Mammals for detailed description of UXO/MEC charge
weights), may require in-situ detonation. Although it is highly
unlikely that all charges would weigh 454 kg, this approach was
determined to be the most conservative for the purposes of impact
analysis. If necessary, these detonations would occur on up to 10
different days (i.e., only one detonation would occur per day). Park
City Wind anticipates up to six detonations could occur in 2025 and
four in 2026. All detonations would occur during daylight hours only
and would not occur from December 1 through May 31, annually; however,
NMFS may approve detonating UXO/MECs on a case-by-case basis in
December and May.
NMFS concurs with Park City Wind that Levels A and Level B
harassment are possible for UXO/MEC detonation activities. Auditory
injury or behavioral harassment may result from exposure to the sounds
produced by UXO/MEC detonation; no non-auditory injury is anticipated.
Cable Laying and Installation
Up to five offshore export cables will transmit electricity
generated by the WTGs to onshore transmission systems in the Town of
Barnstable, Massachusetts. Underground onshore export cables, located
primarily within existing roadway layouts, will connect the landfall
site(s) to one or two new onshore substations in the Town of
Barnstable, Massachusetts. Grid interconnection cables will then
connect the Phase 1 onshore substation to the ISO New England (ISO-NE)
electric grid at Eversource's existing 345 kilovolt substation in West
Barnstable. Park City Wind intends to install all Phase 2 offshore
export cables within the same OECC as the Phase 1 cables but will use
separate landfall sites than Phase 1 in Barnstable. The offshore export
cables will likely be transported directly to the Offshore Development
Area in a cable laying vessel, on an ocean-going barge, or on a heavy
transport vessel (which may also transport the cable laying vessel
overseas) and installed by the cable laying vessel upon arrival. Vessel
types under consideration for cable installation activities are
presented in the COP Volume 1 Table 4.3-1.
Cable burial operations will occur both in the SWDA for the inter-
array cables connecting the WTGs to the ESPs and in the Offshore Export
Cable Corridor (OECC) for the cables carrying power from the ESPs to
the landfall sites. Construction of the OECC and the inter-array cable
installation would take place in 2026 through 2028 (Table 2). The
target depth for cable burial is 1.5 m to 2.5 m (5-8 ft). Therefore,
the seafloor in the direct path of the inter-array, inter-link, and
offshore export cables within the SWDA will be disturbed from the
surface to a depth of 1.5 to 2.5 m (5-8 ft). Where sufficient cable
burial depths cannot be achieved, cable protection would be used. Cable
laying, cable installation, and cable burial activities planned to
occur during the construction of the project may include the following:
jetting (e.g., jet plow or jet trenching); vertical injection;
leveling; mechanical cutting; plowing (with or without jet-assistance);
pre-trenching; boulder removal; and controlled flow excavation. During
construction related activities, including cable laying and
construction material delivery, dynamic positioning (DP) thrusters may
be used to maneuver and maintain station. No blasting is proposed for
cable installation.
Bottom habitat may also be permanently altered to hard bottom
substrate through the installation of cable protection (as described in
Sections 3.2.1.5.4 and 4.2.1.5.4 of BOEM COP Volume I). Potential cable
protection methods include: rock placement on top of the cables (6.4 cm
in diameter or larger); Gabion rock bags on top of the cables; concrete
mattresses; or half-shell pipes or similar (only for cable crossings or
where the cable is laid on the seafloor). Cable protection will be up
to 9 m (30 ft) wide. The offshore export cables will likely be
transported directly to the Offshore Development Area in a cable laying
vessel, on an ocean-going barge, or on a heavy transport vessel (which
may also transport the cable laying vessel overseas) and installed by
the cable laying vessel upon arrival. Phase 1 will consist of two
offshore export cables with a maximum total length of ~202 km (~109
nmi). Phase 2 will consist of two or three offshore export cables with
a maximum total length (assuming three cables) of 356 km (~192 nmi).
The ends of the offshore export cables will likely be protected using
protection conduits put in place at the approach to the ESP
foundation(s). Installation of an offshore export cable is anticipated
to last approximately 9 months for Phase 1 and approximately 13.5
months for Phase 2. Cable installation for each Phase may be continuous
and take up to 2 years. The estimated installation time frame for the
inter-array cables is over a period of approximately 4-5 months for
Phase 1 and 9 months for Phase 2.
The ends of the offshore export cables will likely be protected
using protection conduits put in place at the approach to the ESP
foundation(s) (see COP Volume I Figure 3.2-8). This cable entry
protection system consists of different components of composite
material and/or cast-iron half-shells with suitable corrosion
protection, which protect the cables from fatigue and mechanical loads
as they transition above the seabed and enter the foundation.
[[Page 37616]]
Although a large majority of the cable entry protection system will
likely lie on top of the monopile scour protection (if used), it will
likely extend a short distance beyond the edge of the scour protection.
Additional cable protection may be placed on top of the cable entry
protection system (within the footprint of the scour protection) to
secure the cable entry protection system in place and limit movement of
the cable, which can damage the cable (for specific details see COP
Volume I section 3.2.1.5.4).
For Phases 1 and 2, 66 to 132 kilovolt (kV) inter-array cables will
connect ``strings'' of WTGs to an ESP. The maximum anticipated total
length of the Phase 1 inter-array cables is approximately 225 km (121
nmi) and the maximum anticipated total length of the inter-link cable
is approximately 20 km (11 nmi). The maximum anticipated total length
of the Phase 2 inter-array cables is approximately 325 km (175 nmi) and
the maximum anticipated total length of the inter-link cable is
approximately ~60 km (~32 nmi). The target burial depth of the offshore
export cables will be at least 1.5-2.5 m (5-8 ft) along their entire
length. Like the offshore export cables, all inter-array cables and
inter-link cables will likely be protected with cable entry protection
systems at the approach to the WTG and ESP foundations.
Some dredging of the upper portions of sand waves may be required
prior to cable laying to achieve sufficient burial depth below the
stable sea bottom; large boulders may also need to be relocated.
Dredging may be used to remove the upper portions of sand waves within
the OECC and will be limited only to the extent required to achieve
adequate cable burial depth during cable installation. Dredging could
be accomplished by a trailing suction hopper dredge (TSHD) or
controlled flow excavation.
The amount of habitat disturbance from the use of jack-up and/or
anchored vessels, cable installation, and metocean buoy anchors would
be approximately 4.08 km\2\ (1.58 miles\2\). The total area of
alteration within the SWDA due to foundation and scour protection
installation, jack-up and/or anchored vessel use, inter-array and
inter-link cable installation, potential cable protection (if
required), and metocean buoy anchors is 5.19 km\2\, (2.00 miles\2\)
which is 1.1 percent of the maximum size of the SWDA. Metocean buoys
are small buoys that collect various ocean data. As the noise levels
generated from cable laying and installation work are low, the
potential for take of marine mammals to result is discountable. Park
City Wind is not requesting, and NMFS is not proposing to authorize,
take associated with cable laying activities. Therefore, cable laying
activities are not analyzed further in this document.
Site Preparation
Seabed preparation may be required prior to foundation
installation, scour protection installation, or cable-laying (see
Section 3.3.1.2 and 4.3.1.2 of the COP Volume I). This could include
the removal of large obstructions and/or leveling of the seabed. Large
boulders along the route may need to be relocated prior to cable
installation. Some dredging of the upper portions of sand waves may
also be required prior to cable laying to achieve sufficient burial
depth below the stable sea bottom. However, depending on bottom
conditions, water depth, and contractor preferences, other specialty
techniques may be used in certain areas to ensure sufficient burial
depth. For monopile and jacket pile installation, seafloor preparation
will include required boulder clearance and removal of any obstructions
within the seafloor preparation area at each foundation location. Scour
protection installation will occur pre- or post-installation and will
involve a rock dumping vessel placing scour using fall-pipes, side
dumping, and/or placement using a crane/bucket at each foundation
location (more details can be found in Park City Wind's COP Volume 1
Section 3.3.1.2).
For Phases 1 and 2, a pre-lay grapnel run and pre-lay survey are
expected to be performed to clear obstructions, such as abandoned
fishing gear and other marine debris, and inspect the route prior to
cable laying. A specialized vessel will tow a grapnel rig that hooks
and recovers obstructions, such as fishing gear, ropes, and wires from
the seafloor. Boulder clearance may be required in targeted locations
to clear boulders along the OECC, inter-array cable (IAC) routes, and/
or foundations prior to installation.
Boulder removal would occur prior to installation and would be
completed by a support vessel based. It is currently anticipated that
boulders larger than approximately 0.2-0.3 m (0.7-1 ft) will be avoided
or relocated outside of the final installation corridor to create an
installation corridor wide enough to allow the installation tool to
proceed unobstructed along the seafloor. If there are boulders along
the final route that cannot be moved, a reasonable buffer of up to 5 m
(16 ft) could be utilized. Further details on boulder relocation can be
found in COP Volume 1 Section 3.3.1.3.2.
Dredging would also occur and be limited to the extent required to
achieve adequate cable burial depth during cable installation. Where
dredging is necessary, Park City Wind conservatively assumed that the
dredge corridor would typically be 15 m (50 ft) wide at the bottom (to
allow for equipment maneuverability) with approximately 1:3 sideslopes
for each cable. However, the depth of dredging will vary with the
height of sand waves and the dimensions of the sideslopes will likewise
vary with the depth of dredging and sediment conditions. This dredge
corridor includes up to 1 m (3.3 ft) wide cable installation trench and
up to 3 m (10 ft) wide temporary disturbance zone from the tracks or
skids of the cable installation equipment. The average dredge depth is
approximately 0.5 m (1.6 ft) and may range up to 5.25 m (17 ft) in
localized areas. The total vertical disturbance within sand waves is up
to 8 m (26 ft), which includes dredging and cable installation.
Two installation methods may be used to complete sand leveling
including Trailing Suction Hopper Dredging (TSHD) and controlled flow
excavation (CFE). A TSHD can be used in sand waves of most sizes,
whereas the controlled flow excavation technique is most likely to be
used in areas where sand waves are less than 2 m (6.6 ft) high. A TSHD
vessel contains one or more drag arms that extend from the vessel, rest
on the seafloor, and suction up sediments. Any sediment removed would
be deposited in the dredged material within the OECC. Bottom dumping of
dredged material would only occur within sand waves. CFE is a
contactless dredging tool, providing a method of clearing loose
sediment below submarine cables, enabling burial. The CFE tool draws in
seawater from the sides and then jets this water out from a vertical
down pipe at a specified pressure and volume, which is then positioned
over the cable alignment, enabling the stream of water to fluidize the
sands around the cable. This allows the cable to settle into the trench
under its own weight. Further details on dredging and sand level can be
found in COP Volume I 3.3.1.3.5.
NMFS does not expect site preparation work, including boulder
removal and sand leveling (i.e., dredging), to generate noise levels
that would cause take of marine mammals. Underwater noise associated
with these activities is expected to be similar in nature to the sound
produced by the dynamic positioning (DP) cable lay vessels used during
cable installation activities within the project. Sound
[[Page 37617]]
produced by DP vessels is considered non-impulsive and is typically
more dominant than mechanical or hydraulic noises produced from the
cable trenching or boulder removal vessels and equipment. Therefore,
noise produced by those vessels would be comparable to or less than the
noise produced by DP vessels, so impacts are also expected to be
similar. Additionally, boulder clearance is a discreet action occurring
over a short duration resulting in short term direct effects and sound
produced by boulder clearance equipment would be preceded by, and
associated with, sound from ongoing vessel noise and would be similar
in nature.
NMFS expects that marine mammals would not be exposed to sounds
levels or durations from seafloor preparation work that would disrupt
behavioral patterns. Therefore, the potential for take of marine
mammals to result from these activities is discountable and Park Wind
did not request, and NMFS does not propose to authorize, any Level A
harassment or Level B harassment takes associated with seafloor
preparation work and these activities are not analyzed further in this
document.
Vessel Operation
Park City Wind will utilize various types of vessels over the
course of the 5-year proposed regulations. Park City Wind has
identified several existing port facilities located in Massachusetts,
Rhode Island, Connecticut, New York, and/or New Jersey to support
offshore construction, assembly and fabrication, crew transfer and
logistics, and other operational activities. In addition, some
components, materials, and vessels could come from Canadian and
European ports. A variety of vessels would be used throughout the
construction activities. These range from crew transportation vessels,
tugboats, jack-up vessels, cargo ships, and various support vessels
(Table 4). Details on the vessels, related work, operational speeds,
and general trip behavior can be found in Table 2 of the ITA
application and Table 3.3-1 in the COP Volume 1. In addition to
vessels, helicopters may be used for crew transfer and fast response
visual inspections and repair activities during both construction and
operations. It is not possible at this stage of the project to quantify
the expected use of helicopters and any potential reduction in the
number of vessel trips.
As part of various vessel-based construction activities, including
cable laying and construction material delivery, dynamic positioning
thrusters may be utilized to hold vessels in position or move slowly.
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. Sound
produced by dynamic positioning thrusters would be preceded by, and
associated with, sound from ongoing vessel noise and would be similar
in nature; thus, any marine mammals in the vicinity of the activity
would be aware of the vessel's presence. Construction-related vessel
activity, including the use of dynamic positioning thrusters, is not
expected to result in take of marine mammals. Park City Wind did not
request, and NMFS does not propose to authorize, any take associated
with vessel activity.
During construction and operation, crew transfer vessels (CTVs) and
a service operation vessel (SOV) will be used to conduct maintenance
activities. Although less likely, if an SOV is not used, several CTVs
and helicopters would be used to frequently transport crew to and from
the offshore facilities. Park City Wind has also included potential for
helicopters to be used when rough weather limits or precludes the use
of CTVs and during fast response visual inspections and repair
activities during both construction and operations (COP Volume 1
Sections 3.3.1.12.1 and 4.3.1.12.1). The total vessels expected for use
during the Project are in Table 4; more details can be found in Table 2
of the ITA application.
Assuming the maximum design scenario for each Phase individually,
~3,200 total vessel round trips (an average of approximately six round
trips per day) are expected to occur during offshore construction of
Phase 1 and ~3,800 total vessel round trips (an average of
approximately seven round trips per day) are expected to occur during
offshore construction of Phase 2 (For the purposes of estimating vessel
trips, tugboats and barges are considered one vessel). Due to the range
of buildout scenarios for Phases 1 and 2, Park City Wind expects the
total number of vessel trips from both Phases of New England Wind
combined to be less than the sum of vessel trips estimated for each
Phase independently (section 1.1.2 ITA application). Park City Wind
estimates that, between the 5 major port areas they intend to use, they
expect an average of 15 round trips per day and 443 round trips per
month during peak construction (Table 1 ITA application). Throughout
the entire construction period, they expect an average of 8 round trips
per day and 215 round trips per month (Table 1 ITA application).
Table 4--Type and Number of Vessels Anticipated During Construction and
Operations
------------------------------------------------------------------------
Max number of
Project period Vessel types vessels
------------------------------------------------------------------------
All Foundation Installation.... Transport, 20
Installation, and
Support.
All Foundation Installation.... Crew Transfer.......... 3
All Foundation Installation.... Environmental 8
Monitoring and
Mitigation.
WTG Installation............... Transport, 21
Installation, and
Support.
WTG Installation............... Crew Transfer Vessel... 3
Inter-array Cable Installation. Transport, 7
Installation, and
Support.
Inter-array Cable Installation. Crew Transfer Vessel... 2
ESP Installation............... Transport, 9
Installation, and
Support.
ESP Installation............... Crew Transfer Vessel... 1
Offshore Export Cable Transport, 13
Installation. Installation, and
Support.
Offshore Export Cable Crew Transfer Vessel... 1
Installation.
All Other Construction Crew Transfer Vessel... 4
Activities.
All Other Construction Transport, Survey, and 4
Activities. Support.
------------------------------------------------------------------------
NMFS is proposing to require extensive vessel strike avoidance
measures that would avoid vessel strikes from occurring (see Proposed
Mitigation section). Park City Wind has not requested, and NMFS is not
[[Page 37618]]
proposing to authorize, take from vessel strikes.
Fisheries and Benthic Monitoring
Fisheries and benthic monitoring surveys are being designed for the
project in accordance with recommendations set forth in ``Guidelines
for Providing Information on Fisheries for Renewable Energy Development
on the Atlantic Outer Continental Shelf'' (BOEM, 2019). Park City Wind
would conduct trawl net sampling, video surveillance (drop camera),
plankton (Neuston) net, ventless trap, and tagging surveys.
Specifically, Park City Wind would conduct seasonal trawl surveys
following the Northeast Area Monitoring and Assessment Program (NEAMAP)
survey protocol to sample fish and invertebrates in the SWDA and
control area. The surveys would be comprised of 200 tows per year
conducted for 20 minutes at vessel speed of 3.0 knots. The ventless
trap surveys would follow Massachusetts and Rhode Island Division of
Marine Fisheries protocol to sample lobster, black sea bass, and Jonah
crab. Surveys would be conducted twice per month from May to December
in 30 stations across the SWDA and control areas with 6 lobster traps
and 1 fish pot at each station. Because the drop camera, tagging
efforts, and Neuston nets do not have components with which marine
mammals are likely to interact (i.e., become entangled in or hooked
by), these activities are not anticipated to result in take of marine
mammals and will not be discussed further. Only trap and trawl surveys
have the potential to result in harassment to marine mammals. However,
Park City Wind would implement mitigation and monitoring measures to
avoid taking marine mammals, including, but not limited to, monitoring
for marine mammals before and during trawling activities, not deploying
or pulling trawl gear in certain circumstances, limiting tow times, and
fully repairing nets. A full description of mitigation measures can be
found in the Proposed Mitigation section.
With the implementation of these measures, Park City Wind does not
anticipate, and NMFS is not proposing to authorize, take of marine
mammals incidental to research trap and trawl surveys. Given no take is
anticipated from these surveys, impacts from fishery surveys will not
be discussed further in this document (with the exception of the
description of measures in the Proposed Mitigation section).
Description of Marine Mammals in the Area of Specified Activities
Thirty-eight marine mammal species under NMFS' jurisdiction have
geographic ranges within the western North Atlantic OCS (Hayes et al.,
2022). Park City Wind requested take of all 38 species (comprising 38
stocks) of marine mammals. The majority of takes are requested for only
17 species; the remaining 22 stocks are considered rare in the project
area and Park City Wind is requested a limited amount of take for those
species (e.g., one group size). Sections 3 and 4 of Park City Wind's
ITA 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 in
the application instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS's Stock Assessment Reports (SARs), <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>), and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS's website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 5 lists all species and stocks for which take is expected and
proposed to be authorized for this action 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) level, where known. The MMPA defines PBR 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'' (16 U.S.C. 1362(20)).
PBR values are identified in NMFS's SARs. While no mortality is
anticipated or proposed to be authorized, PBR and annual serious injury
and mortality from anthropogenic sources are included here as gross
indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some stocks, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Atlantic and Gulf of Mexico SARs. All values presented in
Table 5 are the most recent available at the time of publication and,
unless noted otherwise, use NMFS' 2022 SARs (Hayes et al., 2023)
available online at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports</a>.
Table 5--Marine Mammal Species That May Occur in the Project Area and Be Taken, by Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual
ESA/ MMPA Stock abundance (CV, mortalities
Common name Scientific name Stock status; Nmin, most recent PBR or serious
strategic (Y/N) abundance survey) injuries (M/
\1\ \2\ SI) \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
North Atlantic right whale... Eubalaena glacialis............ Western Atlantic.... E,D,Y 338 (0; 332; 2020).. 0.7 8.1
Family Balaenopteridae
(rorquals):
Blue whale................... Balaenoptera musculus.......... Western North E,D,Y UNK (UNK, 402, 2019) 0.8 0
Atlantic.
Fin whale.................... Balaenoptera physalus.......... Western North E,D,Y 6,802 (0.24; 5,573; 11 1.8
Atlantic. 2016).
Humpback whale............... Megaptera novaeangliae......... Gulf of Maine....... -,-,Y 1,396 (0; 1,380; 22 12.15
2016).
Minke whale.................. Balaenoptera acutorostrata..... Canadian Eastern -,-,N 21,968 (0.31; 170 10.6
Coastal. 17,002; 2016).
Sei whale.................... Balaenoptera borealis.......... Nova Scotia......... E,D,Y 6,292 (1.02; 3,098; 6.2 0.8
2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 37619]]
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
Sperm whale.................. Physeter macrocephalus......... North Atlantic...... E,D,Y 4,349 (0.28; 3,451; 3.9 0
2016).
Family Kogiidae:
Dwarf sperm whale \4\........ Kogia sima..................... Western North -,-,N 7,750 (0.38; 5,689; 46 0
Atlantic. 2016).
Pygmy sperm whale \4\........ Kogia breviceps................ Western North -,-,N 7,750 (0.38; 5,689; 46 0
Atlantic. 2016).
Family Ziphiidae:
Cuvier's beaked whale........ Ziphius cavirostris............ Western North -,-,N 5,744 (0.36, 4,282, 43 0.2
Atlantic. 2016).
Blainville's beaked whale.... Mesoplodon densirostris........ Western North -,-,N 10,107 (0.27, 8,085, 81 \5\ 0.2
Atlantic. 2016).
Gervais' beaked whale........ Mesoplodon europaeus........... Western North -,-,N 5,744 (0.36, 4,282, 81 \5\ 0
Atlantic. 2016).
Sowerby's beaked whale....... Mesoplodon bidens.............. Western North -,-,N 10,107 (0.27, 8,085, 81 \5\ 0
Atlantic. 2016).
True's beaked whale.......... Mesoplodon mirus............... Western North -,-,N 10,107 (0.27, 8,085, 81 \5\ 0
Atlantic. 2016).
Northern bottlenose whale.... Hyperoodon ampullatus.......... Western North -,-,N UNK (UNK, UNK, 2016) UNK 0
Atlantic.
Family Delphinidae:
Atlantic spotted dolphin..... Stenella frontalis............. Western North -,-,N 39,921 (0.27; 320 0
Atlantic. 32,032; 2016).
Atlantic white-sided dolphin. Lagenorhynchus acutus.......... Western North -,-,N 93,233 (0.71; 544 27
Atlantic. 54,433; 2016).
Bottlenose dolphin........... Tursiops truncatus............. Western North -,-,N 62,851 (0.23; 519 28
Atlantic--Offshore. 51,914; 2016).
Clymene dolphin.............. Stenella clymene............... Western North -,-,N 4,237 (1.03; 2,071; 21 0
Atlantic. 2016).
Common dolphin............... Delphinus delphis.............. Western North -,-,N 172,897 (0.21; 1,452 390
Atlantic. 145,216; 2016).
Long-finned pilot whale...... Globicephala melas............. Western North -,-,N 39,215 (0.3; 30,627; 306 29
Atlantic. 2016).
Short-finned pilot whale..... Globicephala macrorhynchus..... Western North -,-,Y 28,924 (0.24, 236 136
Atlantic. 23,637, See SAR).
Risso's dolphin.............. Grampus griseus................ Western North -,-,N 35,215 (0.19; 301 34
Atlantic. 30,051; 2016).
False killer whale........... Pseudorca crassidens........... Western North -,-,N 1,791 (0.56, 1,154, 12 0
Atlantic. 2016).
Fraser's dolphin............. Lagenodelphis hosei............ Western North -,-,N UNK (UNK, UNK, 2016) UNK 0
Atlantic.
Killer whale................. Orcinus orca................... Western North -,-,N UNK (UNK, UNK, 2016) UNK 0
Atlantic.
Melon-headed whale........... Peponocephala electra.......... Western North -,-,N UNK (UNK, UNK, 2016) UNK 0
Atlantic.
Pantropical spotted dolphin.. Stenella attenuata............. Western North -,D,N 6,593 (0.52, 4,367, 44 0
Atlantic. 2016).
Pygmy killer whale........... Feresa attenuata............... Gulf of Maine/Bay of -,-,N UNK (UNK, UNK, 2016) UNK 0
Fundy.
Rough-toothed dolphin........ Steno bredanensis.............. Western North -,-,N 136 (1.0, 67, 2016). 0.7 0
Atlantic.
Spinner dolphin.............. Stenella longirostris.......... Western North -,D,N 4,102 (0.99, 2,045, 20 0
Atlantic. 2016).
Striped dolphin.............. Halichoerus grypus............. Western North -,-,N 67,036 (0.29; 529 0
Atlantic. 52,939; 2016).
White-beaked dolphin......... Phoca vitulina................. Western North -,-,N 536,016 (0.31; 4,153 0
Atlantic. 415,344; 2016).
Family Phocoenidae (porpoises):
Harbor porpoise.............. Phocoena phocoena.............. Gulf of Maine/Bay of -,-,N 95,543 (0.31; 851 16
Fundy. 74,034; 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Gray seal \6\................ Halichoerus grypus............. Western North -,-,N 27,300 (0.22; 1,389 4,453
Atlantic. 22,785; 2016).
Harbor seal.................. Phoca vitulina................. Western North -,-,N 61,336 (0.08; 1,729 339
Atlantic. 57,637; 2018).
Harp seal.................... Pagophilus groenlandicus....... Western North -,-,N 7.6M (UNK; 7.1M; 426,000 178,573
Atlantic. 2019).
Hooded seal.................. Cystophora cristata............ Western North -,-,N UNK (UNK, UNK, N/A). UNK 1,680
Atlantic.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS' marine mammal stock assessment reports can be found online at <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> assessments. CV is the coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike). (<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; Committee on Taxonomy
(2022)).
\4\ Accounts for both Kogia species.
\5\ Accounts for all Mesoplodon species.
\6\ NMFS' stock abundance estimate (and associated PBR value) applies to the U.S. population only. Total stock abundance (including animals in Canada)
is approximately 451,431. The annual M/SI value given is for the total stock.
In addition to the species listed in Table 5, the Florida manatees
(Trichechus manatus; a sub-species of the West Indian manatee) has been
previously documented as an occasional visitor to the Northeast region
during summer months (U.S. Fish and Wildlife Service (USFWS), 2019).
However, manatees are managed by the USFWS
[[Page 37620]]
and are not considered further in this document.
Park City Wind also requested take for beluga whales
(Delphinapterus leucas), however, beluga whales are so rare in the
project area that there is no beluga whale stock designated along the
U.S. Eastern Seaboard as it is a more northerly species. In 2014, a
beluga whale was observed in Taunton River, Massachusetts, however,
experts opined that this whale was far from its natural habitat (which
include arctic and subarctic waters) (Swaintek, 2014). It is not
anticipated that beluga whales would occur in the project area;
therefore, beluga whales are not considered further in this document.
Between October 2011 and June 2015, a total of 76 aerial surveys
were conducted throughout the MA and RI/MA WEAs (the Project is
contained within the MA WEA and adjacent to the RI/MA WEA along with
several other offshore renewable energy Lease Areas). Between November
2011 and March 2015, Marine Autonomous Recording Units (MARU; a type of
static passive acoustic monitoring (PAM) recorder) were deployed at
nine sites in the MA and RI/MA WEAs. The goal of the study was to
collect visual and acoustic baseline data on distribution, abundance,
and temporal occurrence patterns of marine mammals (Kraus et al.,
2016). The New England Aquarium conducted additional aerial surveys
throughout the MA and RI/MA WEAs from February 2017 through July 2018
(38 surveys), October 2018 through August 2019 (40 surveys), and March
2020 through July 2021 (12 surveys) (Quintana and Kraus, 2019; O'Brien
et al., 2021a; O'Brien et al., 2021b). As indicated above, 17 species
and stocks in Table 5 are known to temporally and spatially co-occur
with the activity. Additionally, 22 stocks are rare in the project
area. However, Park City Wind has conservatively requested a limited
amount of take to ensure MMPA compliance in the unlikely event that one
or more of these rare species are encountered during project activities
that may result in take (Table 32). Five of the marine mammal species
for which take is requested are listed as threatened or endangered
under the ESA: North Atlantic right, blue, fin, sei, and sperm whales.
In addition to what is included in Sections 3 and 4 of Park City
Wind's ITA application (<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llc-construction-new-england-wind-offshore-wind">https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llc-construction-new-england-wind-offshore-wind</a>), the SARs (<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>), and
NMFS' website (<a href="https://www.fisheries.noaa.gov/species-directory/marine-mammals">https://www.fisheries.noaa.gov/species-directory/marine-mammals</a>), we provide further detail below informing the baseline for
select species (e.g., information regarding current Unusual Mortality
Events (UME) and known important habitat areas, such as Biologically
Important Areas (BIAs) (Van Parijs, 2015)). There are no ESA-designated
critical habitats for any species within the project area (<a href="https://www.fisheries.noaa.gov/resource/map/national-esa-critical-habitat-mapper">https://www.fisheries.noaa.gov/resource/map/national-esa-critical-habitat-mapper</a>).
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 May 2023, five UMEs are active. Four of these UMEs are occurring
along the U.S. Atlantic coast for various marine mammal species. Of
these, the most relevant to the project area are the North Atlantic
right whale, humpback whale, and harbor and gray seal UMEs given the
prevalence of these species in the project area. More information on
UMEs, including all active, closed, or pending, can be found on NMFS'
website at <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events">https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events</a>.
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. Blue whales have been included due to
their ESA-listing and not due to any UME or area of biological
significance. 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 U.S. 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 project area. Any areas of known biological
importance (including the BIAs identified in LaBrecque et al., 2015)
that overlap spatially (or are adjacent) with the project area are
addressed in the species sections below.
North Atlantic Right Whales
The North Atlantic right whale 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 (IUCN) 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., 2022). There is a recovery plan (NMFS, 2005) for the
North Atlantic right whale, and NMFS completed 5-year reviews of the
species in 2012, 2017, and 2022 which concluded no change to the
listing status is warranted.
Designated by NMFS as a Species in the Spotlight, the North
Atlantic right whale is considered among the species with the greatest
risk of extinction in the near future (<a href="https://www.fisheries.noaa.gov/topic/endangered-species-conservation/species-in-the-spotlight">https://www.fisheries.noaa.gov/topic/endangered-species-conservation/species-in-the-spotlight</a>).
The North Atlantic right whale population had only a 2.8 percent
recovery rate between 1990 and 2011 and an overall abundance decline of
23.5 percent from 2011-2019 (Hayes et al., 2022). Since 2010, the North
Atlantic right whale population has been in decline (Pace et al., 2017;
Pace et al., 2021), with a 40 percent decrease in calving rate (Kraus
et al., 2016; Moore et al., 2021). North Atlantic right whale 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 followed by
15 calves during the 2021-2022 calving season. However, mortalities
continue to outpace births, and best estimates indicate fewer than 70
reproductively active females remain in the population.
Critical habitat for North Atlantic right whales is not present in
the project area. However, the project area both spatially and
temporally overlaps a portion of the migratory corridor BIA within
which North Atlantic right whales migrate south to calving grounds
generally in November and December, followed by a northward migration
into feeding areas east and north of the project area in March and
April (LaBrecque et al., 2015; Van Parijs et al.,
[[Page 37621]]
2015). While the project does not overlap any North Atlantic right
whale feeding BIAs, it does spatially overlap a more recently described
important feeding area. North Atlantic right whales have recently been
observed feeding year-round in the region south of Martha's Vineyard
and Nantucket with larger numbers in this area in the winter making it
the only known winter foraging habitat for the species (Leiter et al.,
2017; Quintana-Rizzo et al., 2021).
NMFS' regulations at 50 CFR 224.105 designated Seasonal Management
Areas (SMAs) for North Atlantic right whales in 2008 (73 FR 60173,
October 10, 2008). SMAs were developed to reduce the threat of
collisions between ships and North Atlantic right whales around their
migratory route and calving grounds. The Block Island SMA is near the
proposed project area; this SMA is currently active from November 1
through April 30 of each year and may be used by North Atlantic right
whales for feeding (although to a lesser extent than the area to the
east near Nantucket Shoals) and/or migrating. As noted above, NMFS is
proposing changes to the North Atlantic right whale speed rule (87 FR
46921, August 1, 2022). Due to the current status of North Atlantic
right whales and the spatial proximity overlap of the proposed project
with areas of biological significance, (i.e., a migratory corridor,
SMA), the potential impacts of the proposed project on North Atlantic
right whales warrant particular attention.
North Atlantic right whale presence in the project area is
predominately seasonal; however, year-round occurrence is documented.
Abundance is highest in winter with irregular occurrence during summer
months and similar occurrence rates in spring and fall (O'Brien et al.,
2022; Quintana-Rizzo et al., 2021; Estabrook et al., 2022). Model
outputs suggest that 23 percent of the North Atlantic right whale
population is present from December through May, and the mean residence
time has tripled to an average of 13 days during these months
(Quintana-Rizzo et al., 2021).
North Atlantic right whale distribution can also be derived from
acoustic data. A review of passive acoustic monitoring data from 2004
to 2014 collected throughout the western North Atlantic demonstrated
nearly continuous year-round North Atlantic right whale presence across
their entire habitat range with a decrease in summer months, including
in locations previously thought of as migratory corridors suggesting
that not all of the population undergoes a consistent annual migration
(Davis et al., 2017). To describe seasonal trends in North Atlantic
right whale presence, Estabrook et al. (2022) analyzed North Atlantic
right whale acoustic detections collected between 2011-2015 during
winter (January-March), spring (April-June), summer (July-September),
and autumn (October-December). Winter had the highest presence (75
percent array-days, n = 193), and summer had the lowest presence (10
percent array-days, n = 27). Spring and autumn were similar, where 45
percent (n = 117) and 51 percent (n = 121) of the array-days had
detections, respectively. Across all years, detections were
consistently lowest in August and September. In Massachusetts Bay and
Cape Cod Bay, located outside of the project area, acoustic detections
of North Atlantic right whales increased in more recent years in both
the peak season of late winter through early spring and in summer and
fall, likely reflecting broad-scale regional habitat changes (Charif et
al., 2020). NMFS' Passive Acoustic Cetacean Map (PACM) contains up-to-
date acoustic data that contributes to our understanding of when and
where specific whales (including North Atlantic right whales), dolphin,
and other cetacean species are acoustically detected in the North
Atlantic. These data support the findings of the aforementioned
literature.
In late fall (i.e., November), a portion of the right whale
population (including pregnant females) typically departs the feeding
grounds in the North Atlantic, moves south along the migratory corridor
BIA, including through the project area, to right whale calving grounds
off Georgia and Florida. However, recent research indicates
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). The results of
multistate temporary emigration capture-recapture modeling, based on
sighting data collected over the past 22 years, indicate that non-
calving females may remain in the feeding grounds, during the winter in
the years preceding and following the birth of a calf to increase their
energy stores (Gowan et al., 2019).
Southern New England waters are a migratory corridor in the spring
and early winter and a primary feeding habitat for North Atlantic right
whales during late winter through spring. Right whales 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 North Atlantic right whale habitat-
use patterns within the region over the same time period (Davis et al.,
2020; Meyer-Gutbrod et al., 2022; Quintana-Rizzo et al., 2021; O'Brien
et al., 2022). Since 2010, North Atlantic right whales have reduced
their use of foraging habitats in the Great South Channel and Bay of
Fundy while increasing their use of habitat within Cape Cod Bay as well
as 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). The SWDA and OECC are south and east of
Martha's Vineyard and south and west of Nantucket Islands.
Since 2017, 98 dead, seriously injured, or sublethally injured or
ill North Atlantic right whales along the U.S. and Canadian coasts have
been documented, necessitating a UME declaration and investigation. The
leading category for the cause of death for this ongoing UME is ``human
interaction,'' specifically from entanglements or vessel strikes. As of
May 17, 2023, there have been 36 confirmed mortalities (dead stranded
or floaters) and 33 seriously injured free-swimming whales for a total
of 69 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 98. 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). More information about the North
Atlantic right whale UME is available online at <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2023-north-atlantic-right-whale-unusual-mortality-event">https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2023-north-atlantic-right-whale-unusual-mortality-event</a>.
Humpback Whales
Humpback whales were listed as endangered under the Endangered
Species Conservation Act (ESCA) in June 1970. In 1973, the ESA replaced
the ESCA, and humpbacks continued to be listed as endangered. 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
[[Page 37622]]
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
project area. Bettridge et al. (2015) estimated the size of the West
Indies DPS population at 12,312 (95 percent confidence interval (CI)
8,688-15,954) whales in 2004-05, 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 (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). Kraus et al. (2016) observed humpbacks in
the RI/MA & MA WEAs and surrounding areas during all seasons but most
often during spring and summer months with a peak from April to June.
Acoustic data indicate that this species may be present within the RI/
MA WEA year-round with the highest rates of acoustic detections in the
winter and spring (Kraus et al., 2016).
The project area does not overlap any ESA-designated critical
habitat, 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). However, this BIA is located further
east and north of, and thus, does not overlap, the project area.
Since January 2016, elevated humpback whale mortalities along the
Atlantic coast from Maine to Florida led to the declaration of a UME.
As of May 17, 2023, 191 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. More information is available at
<a href="https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events">https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events</a>.
Fin Whales
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.,
2022). 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).
Kraus et al. (2016) suggest that, compared to other baleen whale
species, fin whales have a high multi-seasonal relative abundance in
the RI/MA & MA WEAs and surrounding areas. Fin whales were observed in
the MA WEA in spring and summer. This species was observed primarily in
the offshore (southern) regions of the RI/MA & MA WEAs during spring
and was found closer to shore (northern areas) during the summer months
(Kraus et al., 2016). Calves were observed three times and feeding was
observed nine times during the Kraus et al. (2016) study. Although fin
whales were largely absent from visual surveys in the RI/MA & MA WEAs
in the fall and winter months (Kraus et al., 2016), acoustic data
indicate that this species is present in the RI/MA & MA WEAs during all
months of the year, although less so in summer months (Morano et al.,
2012; Muirhead et al., 2018; Davis et al., 2020).
New England waters represent a major feeding ground for fin whales.
The project area partially overlaps the fin whale feeding BIA (2,933
km\2\) offshore of Montauk Point, New York from March to October (Hain
et al., 1992; LaBrecque et al., 2015). A separate larger year-round
feeding BIA (18,015 km\2\) located far to the northeast in the southern
Gulf of Maine does not overlap with the project area and would thus not
be impacted by project activities.
Minke Whales
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. Minke whale occurrence is common and widespread in New
England from spring to fall, although the species is largely absent in
the winter (Hayes et al., 2022; Risch et al., 2013). Surveys conducted
in the RI/MA WEAs from October 2011 through June 2015 reported 103
minke whale sightings within the area, predominantly in the spring
followed by summer and fall (Kraus et al., 2016). Recent surveys
conducted in the RI/MA WEAs from February 2017 through July 2018,
October 2018 through August 2019, and March 2020 through July 2021
documented minke whales as the most common rorqual (baleen whales with
pleated throat grooves) sighted in the WEAs. Surveys also reported a
shift in the greatest seasonal abundance of minke whales from spring
(2017-2018) (Quintana and Kraus, 2018) to summer (2018-2019 and 2020-
2021) (O'Brien et al., 2021a, b).
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). However, these BIAs do not overlap
the project area as they are located further east and north. A
migratory route for minke whales transiting between northern feeding
grounds and southern breeding areas may exist to the east of the
proposed project area as minke whales may track warmer waters along the
continental shelf while migrating (Risch et al., 2014).
From 2017 through 2022, elevated minke whale mortalities detected
along the Atlantic coast from Maine through South Carolina resulted in
the declaration of a UME. As of April 14, 2023, a total of 142 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 <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast">https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast</a>.
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
[[Page 37623]]
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).
Although their migratory movements are not well understood, sei
whales are believed to migrate north in June and July to feeding areas
and south in September and October to breeding areas (Mitchell, 1975;
CETAP, 1982; Davis et al., 2020). Although sei whales generally occur
offshore, 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 (LaBrecque et al., 2015). This BIA is located nearby but not
within the project area and is not expected to be impacted by the
Project activities.
Blue Whales
Blue whales are included within this section due to their ESA-
listing status and not to any active BIA or UME in the project area.
Blue whales are widely distributed throughout the world's oceans and
are an ESA-listed species throughout their range. Their Western North
Atlantic Stock occurs in the western North Atlantic and generally
ranges from the Arctic to at least mid-latitude waters. Blue whales are
most frequently sighted in more northerly waters off eastern Canada,
with the majority of records from the Gulf of St. Lawrence by
Newfoundland, Canada (Hayes et al., 2019). They often are found near
the continental shelf edge where upwelling produces concentrations of
krill, their main prey species (Yochem and Leatherwood, 1985; Fiedler
et al., 1998; Gill et al., 2011). The blue whale is not common in the
project area. A 2008 study detected blue whale calls in offshore areas
of the New York Bight on 28 out of 258 days of recordings (11 percent
of the days), mostly during winter (Muirhead et al., 2018). Kraus et
al. (2016) conducted aerial and acoustic surveys between 2011-2015 in
the MA and RI/MA WEAs and surrounding areas. Blue whales were not
visually observed and were only sparsely acoustically detected in the
MA and RI/MA WEAs during winter; the acoustic detection could have been
due to very distant vocalizations. These data suggest that blue whales
are rarely, if at all, present in the MA and RI/MA WEAs (Kraus et al.,
2016). Surveys conducted in 2018-2020, did not result in any sightings
of blue whales in MA and RI/MA WEAs (O'Brien et al., 2021a; O'Brien et
al., 2021b). However, Park City Wind has requested a small amount of
take for blue whales on the minimal chance of encounter.
Much is not known about the blue whale populations, the last
minimum population abundance was estimated at 402 (Hayes et al., 2023).
There are insufficient data to determine population trends for blue
whales. The total level of human caused mortality and serious injury is
unknown, but it is believed to be insignificant and approaching a zero
mortality and serious injury rate (Hayes et al., 2019). There are no
blue whale BIAs or ESA-protected critical habitat identified in the
project area or along the U.S. Eastern Seaboard. There is no UME for
blue whales. More information is available at <a href="https://www.fisheries.noaa.gov/species/blue-whale">https://www.fisheries.noaa.gov/species/blue-whale</a>.
Pinnipeds
Since June 2022, elevated numbers of harbor seal and gray seal
mortalities have occurred across the southern and central coast of
Maine. This event has been declared a UME. Preliminary testing of
samples has found some harbor and gray seals positive for highly
pathogenic avian influenza. While the UME is not occurring in the
project area, the populations affected by the UME are the same as those
potentially affected by the project. Information on this UME is
available online at <a href="https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast">https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast</a>.
The above event was preceded by a different UME, occurring from
2018-2020 (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 in this UME,
which is pending closure. Information on this UME is available online
at <a href="https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along">https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along</a>.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
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 6.
[[Page 37624]]
Table 6--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).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al., 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013). For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
NMFS notes that in 2019a, Southall et al. recommended new names for
hearing groups that are widely recognized. However, this new hearing
group classification does not change the weighting functions or
acoustic thresholds (i.e., the weighting functions and thresholds in
Southall et al. (2019a) are identical to NMFS 2018 Revised Technical
Guidance). When NMFS updates our Technical Guidance, we will be
adopting the updated Southall et al. (2019a) hearing group
classification.
Potential Effects of the Specified Activities on Marine Mammals and
Their Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take 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 how those impacts on individuals are
likely to impact marine mammal species or stocks. General background
information on marine mammal hearing was provided previously (see the
Description of Marine Mammals in the Area of the Specified Activities
section). Here, the potential effects of sound on marine mammals are
discussed.
Park City Wind has requested, and NMFS proposes to authorize, the
take of marine mammals incidental to the construction activities
associated with the project area. In their application and Application
Update Report, Park City Wind presented their analyses of potential
impacts to marine mammals from the acoustic and explosive sources. NMFS
both carefully reviewed the information provided by Park City 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 up to 132 permanent foundations to support WTGs and ESPs
and seafloor mapping using HRG surveys. Additionally, up to 10 UXO/MEC
detonations may occur during construction if they cannot be safely
removed by other means. 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
<a href="https://dosits.org/">https://dosits.org/</a>. 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 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 Hz or
cycles per second. Wavelength is the distance between two peaks or
corresponding points of a
[[Page 37625]]
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 are measured in decibels
(dB), which are 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 100-
fold increase in power and a 30-dB increase is a 1000-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 rule,
all decibel levels referenced to 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;
SEL<INF>ss</INF>), or calculated over periods containing multiple
pulses (SEL<INF>cum</INF>). 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 PTS (permanent
threshold shift) and TTS (temporary threshold shift). Peak sound
pressure is also used to evaluate the potential for gastro-intestinal
tract injury (Level A harassment) from explosives.
For explosives, an impulse metric (Pa-s), which is the integral of
a transient sound pressure over the duration of the pulse, is used to
evaluate the potential for mortality (i.e., severe lung injury) and
slight lung injury. These impulse metric thresholds account for animal
mass and depth.
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 one second), broadband,
atonal transients (American National Standards Institute (ANSI), 1986,
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 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
[[Page 37626]]
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 the
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 Park City 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 Park City
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 (PTS; 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,
but 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
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
[[Page 37627]]
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, 2016b, 2016c;
Finneran, 2018; Nachtigall et al., 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., 2012 and 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 et
al., 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)
for exposures to 3-4 kHz sonar signals, while deep feeding and non-
feeding whales showed a clear response at exposures at lower 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,
[[Page 37628]]
swimming rapidly away, and extending both dive duration and subsequent
non-foraging intervals when the sound source was 3.4-9.5 km 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 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, 2017b;
Falcone et al., 2017; Dunlop et al., 2018; 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 rule 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 fivefold 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 behaviorally sensitive species (e.g.,
Southall et al., 2007) and the effects of wind farm construction in
Europe on these species has 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
[[Page 37629]]
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 PAM data from 2010-2013 and aerial
surveys from 2009-2013 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 of the pile driving site, with declines at up to 20-30 km
of the pile driving site documented in some cases. Similar results
demonstrating the long-distance displacement of harbor porpoises (18-25
km) and harbor seals (up to 40 km) 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 1-2 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; Carroll et al., 2010; 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 (ADDs)) or
the manner in which species use the habitat in the project area are
likely the driving factors of this variation.
NMFS notes the aforementioned studies from Europe involve
installing much smaller piles than Park City Wind proposes to install
and, therefore, we anticipate noise levels from impact pile driving to
be louder. For this reason, we anticipate that the greater distances of
displacement observed in harbor porpoise and harbor seals documented in
Europe are likely to occur off Massachusetts. 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 are primarily transient (with higher abundances in winter
when foundation installation and UXO/MEC detonations would not occur)
and a very small percentage of the large harbor seal population are
only seasonally present with no rookeries established. 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
away while showing no such reaction to the same signal when the signal
was 118 km 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 North Atlantic
right whales, gray whales migrate close to shore (approximately +2 kms)
and are low frequency hearing specialists. The LFA sonar source was
placed within the gray whale migratory corridor (approximately 2 km
offshore) and offshore of most, but not all, migrating whales
(approximately 4 km 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 level was 170 dB rms 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. 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 from the area
(Boyd et al., 2008; Southall et al., 2009; Tyack et al., 2011). Park
City Wind does not anticipate, and NMFS is not proposing to authorize
take of beaked whales and, moreover, the sounds produced by Park City
Wind 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 minimize
the cost of transport (Miksis-Olds, 2006), as has been demonstrated in
Florida manatees (Miksis-Olds, 2006).
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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, although 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 either
stationery pile driving (which they can sense is stationery and
predictable) or significantly lower-level HRG surveys, unless they are
within the area ensonified above behavioral harassment thresholds at
the moment the source is turned on (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 North Atlantic right whales 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 North Atlantic right whales, 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., 2006a;
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., 2018;
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 5-years the proposed rule would be effective could have
similar impacts.
Visual tracking, passive acoustic monitoring, and movement
recording tags were used to quantify sperm whale
[[Page 37631]]
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,
following a phase-in of sound intensity and full array exposures at 1-
13 km (Madsen et al., 2006a; 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 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 North Atlantic
right whales 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 source levels of both the proposed
construction and HRG activities exceed the source levels of the signals
described by Nowacek et al. (2004) and Croll et al. (2001), and noise
generated by Park City Wind's activities at least partially overlap in
frequency with the described signals. 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 in Southern California waters indicated that,
in some cases and at low received levels, tagged blue 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;
Southall et al., 2012b, Southall et al., 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, 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 North Atlantic right whales have been observed
to shift the frequency content of their calls upward while reducing the
rate of calling in areas of increased anthropogenic noise (Parks et
al., 2007). In some cases, animals may cease 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). 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,
[[Page 37632]]
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age, or TTS hearing loss), and existing ambient noise and propagation
conditions.
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. 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, though, the
detection of frequencies above those of the masking stimulus decreases
also. 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 et al., 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 depends 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 in terms of SPL) in the
world's ocean from pre-industrial periods, with most of the increase
from distant commercial shipping (Hil
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