Proposed Rule2023-02497
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Sunrise Wind Offshore Wind Farm Project Offshore New York
Primary source
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Published
February 10, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Sunrise Wind, LLC (Sunrise Wind), a 50/50 joint venture between [Oslash]rsted North America, Inc. ([Oslash]rsted) and Eversource Investment, LLC, 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 (2023-2028) incidental to construction of the Sunrise Wind Offshore Wind Farm Project offshore of New York in a designated lease area on the Outer Continental Shelf (OCS-A-0487). Project activities likely to result in incidental take include pile driving (impact and vibratory), potential 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. The proposed regulations, if adopted, would be effective November 20, 2023-November 19, 2028.
Full Text
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[Federal Register Volume 88, Number 28 (Friday, February 10, 2023)]
[Proposed Rules]
[Pages 8996-9103]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-02497]
[[Page 8995]]
Vol. 88
Friday,
No. 28
February 10, 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 Sunrise Wind Offshore Wind Farm
Project Offshore New York; Proposed Rule
Federal Register / Vol. 88, No. 28 / Friday, February 10, 2023 /
Proposed Rules
[[Page 8996]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 230201-0034]
RIN 0648-BL67
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Sunrise Wind Offshore Wind Farm
Project Offshore New York
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 Sunrise Wind, LLC (Sunrise
Wind), a 50/50 joint venture between [Oslash]rsted North America, Inc.
([Oslash]rsted) and Eversource Investment, LLC, 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 (2023-2028) incidental to
construction of the Sunrise Wind Offshore Wind Farm Project offshore of
New York in a designated lease area on the Outer Continental Shelf
(OCS-A-0487). Project activities likely to result in incidental take
include pile driving (impact and vibratory), potential 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. The proposed regulations, if adopted, would be
effective November 20, 2023-November 19, 2028.
DATES: Comments and information must be received no later than March
13, 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-
0012 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 Sunrise Wind's 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, if adopted, 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 Sunrise Wind Offshore Wind Farm Project within the Bureau of Ocean
Energy Management (BOEM) Renewable Energy Lease Area OCS-A 0487 and
along an export cable corridor to a landfall location in New York. NMFS
received a request from Sunrise Wind for 5-year regulations and an LOA
that would authorize take of individuals of 16 species of marine
mammals by harassment only (four species by Level A harassment and
Level B harassment and 12 species by Level B harassment) incidental to
Sunrise Wind's construction activities. No mortality or serious injury
is anticipated or proposed for authorization. Please see the Estimated
Take of Marine Mammals section below for definitions of harassment.
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. The definitions of all applicable MMPA
statutory terms cited above are included below.
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 Sunrise Wind's activities.
Summary of Major Provisions Within the Proposed Rule
The major provisions within this proposed rule are as follows:
<bullet> Establishing a seasonal moratorium on impact pile driving
during the months of highest North Atlantic right whale (Eubalaena
glacialis) presence in the project area (January 1-April 30);
<bullet> Establishing a seasonal moratorium on any UXO/MEC
detonations during the months of highest North Atlantic right whale
present in the project area (December 1-April 30).
<bullet> Requiring that any UXO/MEC detonations may occur only
during hours of daylight and not during hours of darkness or night.
<bullet> Conducting both visual and passive acoustic monitoring by
trained, NOAA
[[Page 8997]]
Fisheries-approved Protected Species Observers (PSOs) and Passive
Acoustic Monitoring (PAM) operators before, during, and after the in-
water construction activities;
<bullet> Requiring the use of sound attenuation device(s) during
all impact pile driving and UXO/MEC detonations to reduce noise levels;
<bullet> Delaying the start of pile driving if a North Atlantic
right whale is observed at any distance by the PSO on the pile driving
or dedicated PSO vessels;
<bullet> Delaying the start of pile driving if other marine mammals
are observed entering or within their respective clearance zones;
<bullet> Shutting 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> Implementing soft-starts for impact pile driving and using
the least hammer energy possible;
<bullet> A requirement to implement noise abatement system(s)
during all impact pile driving and UXO/MEC detonations;
<bullet> Implementing ramp-up for HRG site characterization survey
equipment;
<bullet> Requiring PSOs to continue to monitor for 30 minutes after
any impact pile driving occurs and for any and after all UXO/MEC
detonations;
<bullet> Increasing 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> Implementing vessel strike avoidance measures;
<bullet> Sound field verification requirements during impact pile
driving and UXO/MEC detonation to measure in situ noise levels for
comparison against the model results; and
<bullet> Implementing best management practices during fisheries
monitoring surveys such as removing gear from the water if marine
mammals are considered at-risk or are interacting with gear.
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 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 (Sunrise Wind Draft Environmental Impact Statement (DEIS) for
Commercial Wind Lease OCS-A 0487) was made available for public comment
on December 16, 2022 (87 FR 77136), beginning the 60-day comment period
ending on February 14, 2023. Additionally, BOEM held three virtual
public hearings on January 18, January 19, and January 23, 2023.
Information contained within Sunrise Wind's incidental take
authorization (ITA) application and this proposed rule 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 proposed rule 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).
Sunrise 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: <a href="https://www.permits.performance.gov/permitting-project/sunrise-wind-farm">https://www.permits.performance.gov/permitting-project/sunrise-wind-farm</a>.
Summary of Request
On November 10, 2021, Sunrise Wind submitted a request for the
promulgation of regulations and issuance of an associated 5-year LOA to
take marine mammals incidental to construction activities associated
with implementation of the Sunrise Wind Offshore Wind Farm Project
(herein ``SWF'') offshore of New York in the BOEM Lease Area OCS-A-
0487. Sunrise Wind's request is for the incidental, but not
intentional, taking of a small number of 16 marine mammal species
(comprising 16 stocks) by Level B harassment (for all 16 species or
stocks) and by Level A harassment (for 4 species or stocks). Neither
Sunrise Wind nor NMFS expects serious injury or mortality to result
from the specified activities nor is any proposed for authorization.
In response to our questions and comments and following extensive
information exchange between Sunrise Wind and NMFS, Sunrise Wind
submitted a final revised application on May 9, 2022, which NMFS deemed
adequate and complete on May 10, 2022. This final application is
available on NMFS' website at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-sunrise-wind-llc-construction-and-operation-sunrise-wind">https://www.fisheries.noaa.gov/action/incidental-take-authorization-sunrise-wind-llc-construction-and-operation-sunrise-wind</a>.
On June 2, 2022, NMFS published a notice of receipt (NOR) of
Sunrise Wind's adequate and complete application in the Federal
Register (87 FR 33470), requesting comments and soliciting information
related to Sunrise Wind's request during a 30-day public comment
period. During the NOR public comment period, NMFS received comment
letters from two environmental non-governmental organizations: Clean
Ocean Action and Oceana. NMFS has reviewed all submitted material and
has taken the material into consideration during the drafting of this
proposed rule. Subsequently, in June 2022, new scientific information
was released regarding marine mammal densities (Robert and Halpin,
2022) and, as such, Sunrise Wind submitted a final Updated Density and
Take Estimation Memo to NMFS on December 15, 2022 that included updated
marine mammal densities and take estimates. This memo is available on
our website at <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-sunrise-wind-llc-construction-and-operation-sunrise-wind">https://www.fisheries.noaa.gov/action/incidental-take-authorization-sunrise-wind-llc-construction-and-operation-sunrise-wind</a>).
NMFS previously issued four Incidental Harassment Authorizations
(IHAs) to [Oslash]rsted for the taking of marine mammals incidental to
marine site characterization surveys (using HRG equipment) of the
Sunrise Wind's BOEM Lease Area (OCS-A 0487) and
[[Page 8998]]
surrounding BOEM Lease Areas (OCS-A 0486, OCS-A 0500) (see 84 FR 52464,
October 2, 2019; 85 FR 63508, October 8 14, 2020; 87 FR 756, January 6,
2022; and 87 FR 61575, October 12, 2022). To date, [Oslash]rsted has
complied with all IHA requirements (e.g., mitigation, monitoring, and
reporting). Information regarding [Oslash]rsted's monitoring results
may be found in the Estimated Take of Marine Mammals section, and the
full monitoring reports can be found on NMFS' website: <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 to further reduce
the likelihood of mortalities and serious injuries to endangered North
Atlantic right whales from vessel collisions, which are a leading cause
of the species' decline and a primary factor in an ongoing Unusual
Mortality Event (87 FR 46921). 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 of the
effective date, NMFS would also notify Sunrise 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 Activity
Overview
Sunrise Wind has proposed to construct and operate a 924 to 1,034
megawatt (MW) wind energy facility (known as Sunrise Wind Farm (SRWF))
in state and Federal waters in the Atlantic Ocean in lease area OCS-A-
0487, located within the Massachusetts and Rhode Island Wind Energy
Area (RI/MA WEA). Sunrise Wind's project would consist of several
different types of permanent offshore infrastructure, including wind
turbine generators (WTGs) and associated foundations, an offshore
converter substation (OCS-DC), offshore substation array cables, and
substation interconnector cables. Specifically, activities to construct
the project include the installation of up to 94 WTGs (at 102 potential
locations) and 1 OCS-DC via impact pile driving; impact and vibratory
pile driving at the cable landfall site; trenching, laying, and burial
activities associated with the installation of the export cable route
from the OCS-DC to the shore-based converter station and inter-array
cables between turbines; site preparation work (e.g., boulder removal);
placement of scour protection around foundations; HRG vessel-based site
characterization surveys using active acoustic sources with frequencies
of less than 180 kHz; detonating up to three UXO/MEC of different
charge weights; 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 on Long Island. Marine mammals exposed to elevated noise levels
during impact and vibratory pile driving, detonations of UXOs, or site
characterization surveys may be taken by Level A harassment and/or
Level B harassment depending on the specified activity.
Dates and Duration
Sunrise Wind anticipates that 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 November 20, 2023 through November 19, 2028.
The estimated schedule, including dates and duration, for various
activities is provided in Table 1 (also see Table 4 and Figure 6 in
Sunrise Wind's application); 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
Specific Activity subsection.
Table 1--Estimated Activity Schedule To Construct and Operate the Sunrise Wind Project
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Project area Project activity Expected timing and duration
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Sunrise Wind Farm (SRWF) Construction.. WTG Foundation Installation..... Q3-Q4 2024; 4-5 months.
OCS-DC Foundation Installation.. Q4 2024; 2-3 days (48-72 hours).
WTG Installation................ Q4 2024-Q2 2025; 9 months.
Seafloor preparation............ Q1-Q2 2024
Array Cable Installation........ Q2-Q3 2025; 7 months.
UXO/MEC detonation.............. Q2 2024; 3 days.
Sunrise Wind Export Corridor (SRWEC) Cable Landfall Installation Q4 2023-Q1 2024; 16 days.
Construction. (casing pipe and sheetpile
installation and removal, HDD).
Offshore Export Cable
Installation.
Route clearance................. Q2 2024
EC Installation................. Q4 2024 to Q1 2025; 8 months.
HRG Survey...................... Q4 2023-Q4 2025; Any time of year.
Operations............................. HRG Survey...................... Q4 2024-Q3 2028; Any time of year.
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Italicized activities do not have the potential to result in take of marine mammals.
[[Page 8999]]
WTG and OCS-DC Foundation Installation
The installation of 94 WTG and 1 OCS-DC foundations would be
limited to May through December, given the seasonal restriction on
foundation impact pile driving from January 1-April 30. As described
previously, Sunrise Wind intends to install all foundations in a single
year over the course of 4 to 5 months. However, it is possible that
monopile installation would continue into a second year depending on
construction logistics and local and environmental conditions that may
influence Sunrise Wind's ability to maintain the planned construction
schedule.
Installation of a single monopile foundation is expected to require
a maximum of 4 hours of active impact hammering, which can occur either
in a continuous 4-hour interval or intermittently over a longer time
period. Installation of a single piled jacket foundation is estimated
to require approximately 48 hours of pile driving per jacket (which
includes up to 6 hours of pile driving per pile). It is assumed that
the pile driving would occur within a 72-hour window (~ 3 days)
including wait time in between pile installation. Pile driving activity
will include a 20-minute soft-start at the beginning of each pile
installation.
Sunrise Wind has provided five scenarios for how many piles may be
installed on a given day. Piles may be installed consecutively (one at
a time) or concurrently (multiple piles at the same time). Potential
daily pile driving scenarios include:
<bullet> Consecutive installation of two WTG monopiles or four OCS-
DC pin piles consecutively in 1 day for 53 days;
<bullet> Consecutive installation of three WTG monopiles or four
OCS-DC pin piles consecutively in 1 day for 36 days;
<bullet> Concurrent installation of four WTG monopiles in 1 day,
two each by two different installation vessels operating concurrently
in close proximity to each other (``Proximal'', i.e. 3 nautical miles
apart) for 25.5 days, plus 4 OCS-DC pin piles per day for 2 days;
<bullet> Concurrent installation of four WTG monopiles in 1 day,
two each by two different installation vessels operating concurrently
at long distances from each other (``Distal'', i.e. opposite ends of
the SRWF) for 25.5 days plus four OCS-DC pin piles per day for 2 days;
or
<bullet> Concurrent installation of two WTG monopiles by one vessel
and four OCS-DC pin piles by a second vessel for 2 days followed by two
WTG monopiles per day by a single vessel for 49 days.
Sunrise Wind anticipates that the first WTGs would become
operational in Q3 2025 after installation is completed and all
necessary components, such as array cables, OCS-DC, export cable
routes, and onshore substations are installed. Turbines would be
commissioned individually by personnel on location, so the number of
commissioning teams would dictate how quickly turbines would become
operational. Sunrise Wind expects that all turbines will be
commissioned by Q4 2025.
UXO/MEC Detonations
Based on preliminary survey data, Sunrise Wind estimates a maximum
of 3 days of UXO/MEC detonation may occur with up to one UXO/MEC being
detonated per day. Any UXO/MEC detonation would occur during daylight
hours only after proper marine mammal monitoring is conducted (see
Proposed Monitoring and Reporting section). Sunrise Wind anticipates
UXO/MEC detonation would be limited to Q2 2024. Sunrise Wind would not
detonate UXOs/MECs between December and April.
Cable Landfall Construction
Cable landfall construction is one of the first activities
scheduled to occur, sometime between Q4 2023-Q1 2024. In their
application, Sunrise Wind indicated they would install and remove up to
two casing pipes and supporting goal posts over 36 days; however, the
project has been refined such that only one casing pipe and goal posts
would be installed and removed over 16 days. Installation of the single
casing pipe may take up to 3 hours of pneumatic hammering on each of 2
days for installation. Removal of the casing pipe is anticipated to
require approximately the same amount of pneumatic hammering and
overall time, or less, meaning the pneumatic pipe ramming tool may be
used for up to 3 hours per day over 4 days. Up to 22 sheet piles may be
installed to support the work. Sheet pile may require up to 2 hours of
vibratory piling and up to 4 sheet piles may be installed per day
(total of 8 hours of vibratory pile driving per day). Removal of the
goal posts may also involve the use of a vibratory hammer and likely
require approximately the same amount of time as installation (6 days
total). Thus, use of a vibratory pile driver to install and remove
sheet piles may occur on up to 12 days at the landfall location.
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 four vessels working concurrently in
different sections of the Lease Area and SRWEC corridor. During the
first year of construction (when the majority of foundations and cables
are installed), Sunrise Wind estimates that a total of 12,275 km may be
surveyed over 175 vessel days within the Lease Area and along the SRWEC
corridor in water depths ranging from 2 m (6.5 ft) to 55 m (180 ft).
During non-construction years (Yrs 3-5), Sunrise Wind estimates 6,311.2
km would be surveyed over 90.2 vessel days per year. Each day that a
survey vessel covers 70 km (44 miles) of survey trackline is considered
vessel day. For example, Sunrise Wind would consider two vessels
operating concurrently, with each surveying 70 km (44 miles), two
vessel days. Sunrise Wind anticipates that each vessel would survey an
average of 70 km (44 miles) per day, assuming a 4 km/hour (2.16 knots)
vessel speed and 24-hour operations. In some cases, vessels may conduct
daylight-only 12-hour nearshore surveys covering half that distance (35
km or 22 miles). Over the course of 5 years, HRG surveys would be
conducted at any time of year for a total of 48,484 km over 622 vessel
days. In this schedule, Sunrise Wind accounted for periods of down-time
due to inclement weather or technical malfunctions.
Specific Geographic Region
Sunrise Wind would construct the SRWF in Federal waters offshore of
New York (Figure 1). The lease area OCS-A 0487 is part of the Rhode
Island/Massachusetts Wind Energy Area (RI-MA WEA). The Lease Area
covers approximately 86,823 acres (351 km\2\) and is located
approximately 18.9 statute miles (mi) (16.4 nautical miles (nmi), 30.4
kilometers (km)) south of Martha's Vineyard, Massachusetts;
approximately 30.5 mi (26.5 nmi, 48.1 km) east of Montauk, New York;
and 16.7 mi (14.5 nmi, 26.8 km) from Block Island, Rhode Island Water
depths in the Lease Area range from 35 to 62 m (115-203 ft), averaging
49 m (160.8 ft), while water depths along the SRWEC corridor range from
5.7 to 67 m (18.7 to 219.8 ft). The cable landfall construction area
would be approximately 5.7 m (18.7 ft) in depth. Cables would come
ashore at the Smith Point County Park.
Sunrise 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
[[Page 9000]]
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 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 RIS likely in association with
a tidal mixing front.
The waters in the vicinity of the SRWF and SRWEC are transitional
waters positioned between the continental slope and the coastal
environments of Long Island Sound and Narragansett Bay. 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 at the SRWF
and along the SRWEC, including the results of site-specific benthic
habitat assessments, can be found within COP section 4.4.2, COP
Appendices M1--Benthic Resources Characterization Report--Federal
Waters, M2--Benthic Resources Characterization Report--New York State
Waters, and M3--Benthic Habitat Mapping Report.
[[Page 9001]]
[GRAPHIC] [TIFF OMITTED] TP10FE23.000
Detailed Description of Specific Activity
Below, we provide detailed descriptions of Sunrise 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.
Installation of WTG Foundations
Sunrise Wind plans to install up to 94 WTG monopile foundations
with a maximum diameter tapering from 7 m above the waterline to 12 m
(39 ft) below the waterline (7/12 m monopile (see Figure 3 in Sunrise
Wind's application)) in lease area OCS-0487 spaced in a 1 nmi x 1 nmi
grid pattern. The Project will generate between 924 to 1,034 MW of
renewable energy. Although up to 94 WTGs are expected to be installed,
Sunrise Wind has accounted for up to 8 potential locations where WTG
installation is begun but unable to be completed due to environmental
or engineering constraints (i.e.,only 94 WTGs will be installed but
within 102 potential locations).
Figure 3 in Sunrise Wind's application provides a conceptual
example of the WTG support structures (i.e., towers and foundations),
which will be designed to withstand 500-year hurricane wind and wave
conditions, and the external platform level will be designed above the
1,000-year wave scenario. A WTG monopile foundation typically consists
of a single steel tubular section with several sections of rolled steel
plate welded together. Secondary structures on each WTG monopile
foundation will include a boat landing or alternative means of safe
access (e.g., Get Up Safe--a motion compensated hoist system allowing
vessel to foundation personnel transfers without a boat landing),
ladders, a crane, and other ancillary components.
A typical monopile installation sequence begins with the monopiles
transported directly to the Sunrise Wind Farm 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 4,000 kJ impact pile driver
(although, in general, only up to 3,200 kJ will be necessary except for
potentially 1 strike at 4,000 kJ) to a maximum penetration depth of 50
m (164 ft). Installation of each monopile will include a 20-minute
soft-start where lower hammer energy is used at the beginning of each
pile installation. Under normal conditions, after completion of the 20-
minute soft-start period, installation of a single monopile foundation
is estimated to require 1-4 hours of active pile driving; however,
breaks may be necessary such that 1-4 hours of pile driving occurs over
several more hours (up to 12 hours). Sunrise Wind anticipates it would
then take approximately 4 hours to move to the next piling location.
Once at the new location, a 1-hour monitoring period would occur such
that there would be no less than 5 hours between each pile
installation. In total,
[[Page 9002]]
376 hours (94 WTGs x 4 hours each) would be the maximum amount of time
impact monopile driving would occur over the course of 1 year. Sunrise
Wind is proposing to install foundations consecutively or concurrently
(see Dates and Duration section). Impact pile driving associated with
WTG foundation installation would be limited to the months of May
through December and is currently scheduled to be conducted during Q3
and Q4 2024. Installation of WTG foundations is anticipated to result
in the take of marine mammals due to noise generated during pile
driving.
Sunrise Wind has proposed to conduct pile driving 24-hours per day.
Once construction begins, Sunrise Wind would proceed as rapidly as
possible, while meeting all required mitigation and monitoring
measures, to reduce the total duration of construction. Orsted, the
parent company of Sunrise Wind, is currently analyzing data from pilot
projects investigating the efficacy of technology to monitor (visually
and acoustically) marine mammals during nighttime and reduced
visibility conditions. 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 Sunrise 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.
Offshore Converter Station (OCS-DC)
Sunrise Wind would install a single OCS-DC for the project on a
jacket foundation (see Figure 4 in Sunrise Wind's application). A piled
jacket foundation is formed of a steel lattice construction (comprising
tubular steel members and welded joints) secured to the seabed by means
of hollow steel pin piles attached to the jacket. The piled jacket
foundation will have four legs with two pin piles per leg (eight piles
total). The platform height will be up to 26.8 m (88 ft) with a leg
diameter of up to 4.6 m (15 ft) and a pile diameter of up to 4 m (13
ft). Installation of OCS-DC jacket foundation pin piles (two per leg,
eight total) will be performed using an impact pile driver with a
maximum hammer energy of 4,000-kJ to a maximum penetration depth of 90
m (295 ft). It is assumed that installation of the jacket foundation
would require 48 hours of pile driving total (6 hours per pile), which
would occur over 3 days. The current schedule estimates the OCS-DC
jacket foundation would be installed in Q4 2024. Installation of the
OCS-DC jacket foundation is anticipated to result in the take of marine
mammals due to noise generated during pile driving.
The OCS-DC requires the withdrawal of raw seawater through a
cooling water intake structure (CWIS) to dissipate heat produced
through the AC to DC conversion and then discharge this water as
thermal effluent to the marine receiving waters. It includes intake
pipes and sweater lift pumps (SWLP), course filters,
electrochlorination system, heat exchange system, and a dump caisson.
The OCS-DC would discharge non-contact cooling water (NCCW) and non-
contact stormwater to the marine receiving waters. The design intake
flow (DIF) for the OCS-DC is 8.1 million gallons per day (MGD);
however, the Average Flow Intake (AFI) will generally range from 4.0
MGD to 5.3 MGD. The rate at which seawater would be taken (e.g. maximum
through-screen velocity [TSV]) is 0.1525 m/s [0.5 ft/s]). The dump
caisson consists of a single outlet vertical pipe oriented downward in
the water column. The dump caisson is the primary discharge point for
the OCS-DC. Pollutants discharged at the dump caisson will include NCCW
and residual chlorine. The temperature of the water exiting the heat
exchange system will depend on the ambient air temperature, ambient
water temperature, power output, and other factors. Sunrise Wind
indicated the maximum temperature under all operating scenarios and
conditions will not exceed 32 [deg]C (90 [deg]F) and the thermal plume
is not expected to extend beyond 30 m of the dump caisson. No take of
marine mammals would occur due to water withdrawal or thermal
discharge.
Cable Landfall Construction
Installation of the SRWF export cable landfall will be accomplished
using a horizontal directional drilling (HDD) methodology. HDD will be
used to connect the SRWEC offshore cable to the Onshore Transmission
Cable at the landfall location and to cross the Intercoastal Waterway
(ICW) from Fire Island to mainland Long Island. The drilling equipment
will be located onshore and used to create a borehole, one for each
cable, from shore to an exit point on the seafloor approximately 0.5 mi
(800 m) offshore. At the seaward exit site for each borehole,
construction activities may include the temporary installation of a
casing pipe, supported by sheet pile goal posts, to collect drilling
mud from the borehole exit point. Additionally, 10 sheet piles may be
used to support the casing pipe and help to anchor/stabilize the vessel
which will be collecting drilling fluid. Installation of up to two
casing pipes (one at each HDD exit pit location) would be completed
using pneumatic pipe ramming equipment while installation of sheet pile
for goal posts would be completed using a vibratory pile driving
hammer. These activities would not occur simultaneously as some of the
same equipment on the barge is necessary to conduct both types of
installations. All installation activities would occur during daylight
periods.
Sunrise Wind would install a single casing pipe at an 11-12-degree
angle with the seabed so that the casing pipe creates a straight
alignment between the point of penetration at the seabed and the
construction barge. Casing pipe installation will occur from the
construction barge and be accomplished using a pneumatic pipe ramming
tool (e.g., Grundoram Taurus or similar) with a hammer energy of up to
18 kJ. If necessary, additional sections of casing pipe may be welded
together on the barge to extend the length of the casing pipe from the
barge to the penetration depth in the seabed.
Installation of the single casing pipe may take up to 3 hours of
pneumatic hammering on each of the 2 days for installation.
Installation time will be dependent on the number of pauses required to
weld additional sections onto the casing pipe. Removal of the casing
pipe is anticipated to require approximately the same amount of
pneumatic hammering and overall time, or less, meaning the pneumatic
pipe ramming tool may be used for up to 3 hours per day on up to 4
days.
Up to six goal posts may be installed to support the casing pipe
between the barge and the penetration point on the seabed. Each goal
post would be composed of two vertical sheet piles installed using a
vibratory hammer such as an American Pile Equipment (APE) model 300 (or
similar). A horizontal cross beam connecting the two sheet piles would
then be installed to provide support to the casing pipe. Up to 10
additional sheet piles may be installed to help anchor the barge and
support the construction activities. This results in a total of up to
22 sheet piles. Installation of the goal posts would require up to 6
days. Sheet pile may require up to 2 hours of vibratory piling and up
to four sheet piles may be installed per day (total of 8 hours of
vibratory pile driving per day). Removal of the goal posts may also
involve the use of a vibratory hammer and likely require approximately
the same amount of time
[[Page 9003]]
as installation (6 days total). Thus, use of a vibratory pile driver to
install and remove sheet piles may occur on up to 12 days at the
landfall locations. Installation and removal of the casing pipe and
goal posts is anticipated to result in the take of marine mammals due
to noise generated during pile driving.
UXO/MEC Detonations
Sunrise Wind anticipates the potential for construction activities
to encounter UXO/MECs on the seabed within the SRWF and along the SRWEC
corridor. 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 (Sunrise Wind
2022). Sunrise Wind follows an industry standard As Low as Reasonably
Practicable (ALARP) process that minimizes the number of potential
detonations (COP Appendix G2, (Sunrise-Wind 2021).
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) moving
the UXO/MEC away from the activity (lift and shift), (3) cutting the
UXO/MEC open to apportion large ammunition or deactivate fused
munitions, using shaped charges to reduce the net explosive yield of a
UXO/MEC (low-order detonation), or (4) 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 would in-situ high-order UXO/MEC detonation
be pursued. To detonate a UXO/MEC, a small charge would be placed on
the UXO/MEC and ignited, causing the UXO/MEC to then detonate, which
could result in the take of marine mammals.
To better assess the likelihood of encountering UXO/MECs during
project construction, Sunrise Wind has and will continue to conduct 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, Sunrise Wind assumes that up to three UXO/MEC
454-kg (1000 pounds; lbs) charges, which is the largest charge that is
reasonably expected to be encountered, may require in situ detonation.
Although it is highly unlikely that all three 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 3 different days (i.e., only one detonation would occur
per day). In the event that high-order removal (detonation) is
determined to be the preferred and safest method of disposal, all
detonations would occur during daylight hours. Sunrise Wind would avoid
detonating UXO/MECs from December 1 through April 30 to provide
protection for North Atlantic right whales during the timeframe they
are expected to occur more frequently in the project area. UXO/MEC
detonation is anticipated to result in the take of marine mammals due
to noise.
HRG Surveys
HRG surveys would be conducted to identify any seabed debris and to
support micrositing of the WTG and OCS-DC foundations and cable routes.
These surveys may utilize active acoustic equipment such as multibeam
echosounders, side scan sonars, shallow penetration sub-bottom
profilers (SBPs) (e.g., Compressed High-Intensity Radiated Pulses
(CHIRPs) non-parametric SBP), medium penetration sub-bottom profilers
(e.g., sparkers and boomers), ultra-short baseline positioning
equipment, and marine magnetometers, some of which are expected to
result in the take of marine mammals. Equipment may be mounted to the
survey vessel or Sunrise Wind 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
four vessels. On average, 70-line km will be surveyed per vessel each
survey day at approximately 7.4 km/hour (4 knots) on a 24-hour basis
although some vessels may only operate during daylight hours (~12-hour
survey vessels). During the construction phase (Yr1 and Yr2), an
estimated 24,550 survey line km, plus in-fill and re-surveys, may be
necessary to survey the inter-array cables and the Sunrise Wind Export
Cable in water depths ranging from 2 m (6.5 ft) to 55 m (180 ft). HRG
surveys are anticipated to operate at any time of year for a maximum of
351 active sound source days over the 2 years of construction. During
the operations phase (Yrs 3-5), an estimated 6,311 km per year for 3
years (18,933 km total) may be surveyed in the Sunrise Wind Farm and
along the Sunrise Wind Export Cable. Using the same estimate of 70 km
of survey completed each day per vessel, approximately 90 days of
survey would occur each year for a total of up to 270 active sound
source days over the 3-year operations period. In total, across all 5
years, a total of 43,484 kms of trackline may be surveyed.
Of the HRG equipment types proposed for use, the following sources
have the potential to result in take of marine mammals:
<bullet> Shallow penetration sub-bottom profilers (SBPs) to map the
near-surface stratigraphy (top 0 to 5 m (0 to 16 ft) of sediment below
seabed). A CHIRP system emits sonar pulses that increase in frequency
over time. The pulse length frequency range can be adjusted to meet
project variables. These are typically mounted on the hull of the
vessel or from a side pole.
<bullet> Medium penetration SBPs (boomers) to map deeper subsurface
stratigraphy as needed. A boomer is a broad-band sound source operating
in the 3.5 Hz to 10 kHz frequency range. This system is typically
mounted on a sled and towed behind the vessel.
<bullet> Medium penetration SBPs (sparkers) to map deeper
subsurface stratigraphy as needed. A sparker creates acoustic pulses
from 50 Hz to 4 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 2 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) will 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 or do not produce noise. Hence, no harassment
is reasonably expected to occur from the operation of these sources.
[[Page 9004]]
Table 2--Summary of Representative HRG Survey Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source
Operating level Source Pulse Repetition Beamwidth
Equipment type Representative model frequency SPLrms level 0-pk duration rate (Hz) (degrees) Source
(kHz) (dB) (dB) (ms)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sub-bottom profiler............. EdgeTech 216.......... 2-16 195 - 20 6 24 MAN
EdgeTech 424.......... 4-24 176 - 3.4 2 71 CF
Edgetech 512.......... 0.7-12 179 - 9 8 80 CF
GeoPulse 5430A........ 2-17 196 - 50 10 55 MAN
Teledyn Benthos CHIRP 2-17 197 - 60 15 100 MAN
III--TTV 170.
Sparker......................... Applied Acoustics Dura- 0.3-1.2 203 211 1.1 4 Omni CF
Spark UHD (400 tips,
500 J).
Boomer.......................... Applied Acoustics 0.1-5 205 211 0.6 4 80 CF
triple plate S-Boom
(700-1,000 J).
--------------------------------------------------------------------------------------------------------------------------------------------------------
- = not applicable; ET = EdgeTech; J = joule; kHz = kilohertz; dB = decibels; SL = source level; UHD = ultra-high definition; AA = Applied Acoustics;
rms = root-mean square; [micro]Pa = microPascals; re = referenced to; SPL = sound pressure level; PK = zero-to-peak pressure level; Omni =
omnidirectional source.
\a\ The Dura-spark measurements and specifications provided in Crocker and Fratantonio (2016) were used for all sparker systems proposed for the survey.
These include variants of the Dura-spark sparker system and various configurations of the GeoMarine Geo-Source sparker system. The data provided in
Crocker and Fratantonio (2016) represent the most applicable data for similar sparker systems with comparable operating methods and settings when
manufacturer or other reliable measurements are not available.
\b\ Crocker and Fratantonio (2016) provide S-Boom measurements using two different power sources (CSP-D700 and CSP-N). The CSP-D700 power source was
used in the 700 J measurements but not in the 1,000 J measurements. The CSP-N source was measured for both 700 J and 1,000 J operations but resulted
in a lower SL; therefore, the single maximum SL value was used for both operational levels of the S-Boom.
Cable Laying and Installation
Cable burial operations would occur both in SRWF for the inter-
array cables connecting the 94 WTGs to single OCS-DC and in the SRWEC
corridor for cables carrying power from the OCS-DC to shore. The
offshore export and inter-array cables would be buried in the seabed at
a target depth of up to 1.2 to 2.8 m (4 to 6 ft) and buried onshore up
to the transition joint bays. All cable burial operations would follow
installation of the monopile foundations as the foundations must be in
place to provide connection points for the export cable and inter-array
cables. Cable laying, cable installation, and cable burial activities
planned to occur during the construction of the Sunrise Wind project
may include the following: jetting; vertical injection; leveling;
mechanical cutting; plowing (with or without jet-assistance); pre-
trenching; boulder removal; and controlled flow excavation.
Some dredging may be required prior to cable laying due to the
presence of sandwaves. Sandwave clearance may be undertaken where cable
exposure is predicted over the lifetime of the Project due to seabed
mobility. This facilitates cable burial below the reference seabed.
Alternatively, sandwave clearance may be undertaken where slopes become
greater than approximately 10 degrees (17.6 percent), which could cause
instability to the burial tool. The work could be undertaken by
traditional dredging methods such as a trailing suction hopper.
Alternatively, controlled flow excavation or a sandwave removal plough
could be used. In some cases, multiple passes may be required. The
method of sandwave clearance Sunrise Wind chooses would be based on the
results from the site investigation surveys and cable design.
As the noise levels generated from cable laying and installation
work are low, the potential for take of marine mammals to result is
discountable. Sunrise 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.
Temporary Pier Construction
Construction of the cable landfall at Smith Point County Park
parking lot will require equipment and materials to transit from Long
Island to Fire Island. The Smith Point Bridge, the only vehicle access
to the Smith Point County Park parking lot, has had its posted weight
limitation of 15 tons gross weight due to structural condition issues
and concerns over accelerated aging. Due to these weight limitations,
Sunrise Wind will utilize a transport barge and temporary landing
structure (pier) to transport the heavy construction equipment and
materials necessary to construct the Sunrise Wind Farm Project across
the Intracoastal Waterway (ICW) to Smith Point County Park. The
materials moved using the barge and temporary equipment are required to
construct the Project and includes equipment needed to complete the HDD
work and onshore civil works that are otherwise too heavy to travel
across the Smith Point Bridge. In addition to the temporary pier on
Fire Island, temporary mooring and breasting dolphins will be installed
near the boat ramp at the Smith Point Marina on the Long Island side of
the ICW to facilitate safe loading and unloading of the barge at the
Smith Point Marina boat launch on Long Island.
The temporary pier will require the installation of up to 26 total
production piles that will remain the entire time the temporary pier is
in place. Temporary piles may be used to support a steel-framed
template used to ensure installation of the bent production piles in
the correct positions. The temporary piles may include up to 24 H-
shaped or cylinder piles of the same size as the production piles.
Therefore, a total of 50 piles (up to 26 production piles and up to 24
temporary piles) may be installed, and in some cases removed, during
construction.
Installation and removal of the up to 24 temporary piles would be
completed using only vibratory pile driving equipment. The up to 26
production piles would first be driven using a vibratory hammer
followed by an impact hammer. Both production and temporary piles will
be removed using vibratory pile driving. It is anticipated that
installation of the pier will occur over approximately 3 to 4 weeks in
and around December 2023. Installation of up to 26 production piles may
result in a total of up to 351 minutes (5 hours 51 min) of vibratory
pile driving (26 x 13.5 min) and 39 minutes of impact pile driving (26
x 1.5 min). Installation and removal of up to 24 temporary piles may
require up to 720 minutes (16 hours) of vibratory pile driving only (2
x 24 x 15 min). The maximum total pile driving time for installation is
therefore 1,071 min (17 hours 51 min) of vibratory pile driving and 39
minutes of impact pile driving. Following completion of the landfall
construction work on Fire Island, the temporary pier is expected to be
removed in approximately April or May of 2025. Removal of the temporary
pier would involve the removal of all 26 production piles using a
vibratory hammer. Thus, the total duration of
[[Page 9005]]
vibratory pile driving during pier removal may be up to 390 min (6
hours 30 min; 26 x 15 min).
While pile driving would result in Level B harassment isopleths up
to approximately 750 m from the piles (as described in Sunrise Wind's
Temporary Pier Memo (available 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>), the very short duration of pile driving,
the limited harassment area, the location of the harassment area (in an
area where marine mammals are not typically present), and the
implementation of monitoring and mitigation measures (see Proposed
Mitigation and Proposed Monitoring and Reporting sections), Sunrise
Wind is not requesting, and NMFS is not proposing to authorize, take of
marine mammals incidental to temporary pier and breasting and mooring
dolphin construction activities.
Vessel Operation
Sunrise Wind will utilize various types of vessels over the course
of the 5-year proposed regulations. Sunrise Wind is evaluating the
potential use of several existing port facilities located in New York,
Connecticut, Maryland, Massachusetts, New Jersey, Rhode Island, and
Virginia to support offshore construction, assembly and fabrication,
crew transfer and logistics. The primary construction ports that are
expected to be used during construction include: Albany and/or
Coeymans, New York; Port of New London, Connecticut; and Port of
Dainsville-Quonset Point, Rhode Island.
The largest vessels are expected to be used during the WTG
installation phase with floating/jackup crane barges, cable-laying
vessels, supply/crew vessels, and associated tugs and barges
transporting construction equipment and materials. Large work vessels
(e.g., jack-up installation vessels and cable-laying vessels) for
foundation and WTG installation will generally transit to the work
location and remain in the area until installation time is complete.
These large vessels will move slowly over a short distance between work
locations. Transport vessels will travel between several ports and the
SRWF over the course of the construction period following mandatory
vessel speed restrictions (see Proposed Mitigation section). These
vessels will range in size from smaller crew transport boats to tug and
barge vessels. However, construction crews responsible for assembling
the WTGs will hotel onboard installation vessels at sea, thus limiting
the number of crew vessel transits expected during the installation of
the SRWF.
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. Sunrise Wind did not
request, and NMFS does not propose to authorize, any take associated
with vessel activity.
During operation, up to three crew transfer vessels and a service
operation vessel will be used to conduct maintenance activities.
Sunrise Wind has also included potential for helicopters to be used in
lieu of crew transfer vessels. The use of helicopters is included in
Table 3 below; however, it is important to note that Sunrise Wind has
indicated that there are a number of uncertainties regarding the how
many trips will be made using helicopters, the number of passengers to
be carried, and the vessels to which those passengers would be
transported. Therefore, the total number of vessel trips shown in Table
3 has not been reduced based on the anticipated helicopter flights. As
such, the number of crew transfer vessel trips may be less than
depicted here.
Table 3--Type and Number of Vessels and Number of Vessel Trips
Anticipated During Construction and Operations
------------------------------------------------------------------------
Max number of Max annual
Vessel types simultaneous number of
vessels return trips
------------------------------------------------------------------------
Wind Turbine Foundation Installation (Yrs 1-2)
------------------------------------------------------------------------
Heavy Lift Installation Vessel.......... 2 20
Heavy Transport Vessel.................. 4 50
Platform Supply Vessel.................. 2 80
In-field support tug.................... 2 50
Vessel for Bubble Curtain............... 1 30
Crew Transport Vessel................... 1 50
Monitoring Vessel....................... 4 102
Completion Vessel....................... 1 50
Fall Pipe Vessel........................ 1 6
------------------------------------------------------------------------
Turbine Installation (Yrs 1-2)
------------------------------------------------------------------------
Installation Vessel..................... 1 26
Support Vessel.......................... 1 9
------------------------------------------------------------------------
Array Cable Installation (Yrs 1-2)
------------------------------------------------------------------------
Pre-Lay Grapnel Run..................... 1 5
Boulder Clearance Vessel................ 1 5
Sandwave Clearance Vessel............... 1 3
Cable Laying Vessel..................... 3 3
[[Page 9006]]
Cable Burial Vessel..................... 2 3
Walk to Work Vessel (SOV)............... 1 6
Crew Transport Vessel................... 1 260
Survey Vessel........................... 4 8
Construction Vessel..................... 2 4
Fall Pipe Vessel........................ 2 10
------------------------------------------------------------------------
Offshore Converter Station Installation (Yrs 1-2)
------------------------------------------------------------------------
Primary Installation Vessel............. 3 3
Transport Vessel........................ 2 2
Support Vessels......................... 11 5
Fall Pipe Vessel........................ 1 2
------------------------------------------------------------------------
Offshore Export Cable Installation (Yrs 1-2)
------------------------------------------------------------------------
Pre-Lay Grapnel Run..................... 1 1
Boulder Clearance Vessel................ 1 1
Sandwave Clearance Vessel............... 1 1
Cable Laying Vessel..................... 3 6
Cable Burial Vessel..................... 2 4
Tugs.................................... 4 8
Crew Transport Vessel................... 1 260
Guard Vessel/Scout Vessel............... 5 9
Survey Vessel........................... 2 6
Fall Pipe Vessel........................ 1 2
Construction Vessel..................... 2 2
------------------------------------------------------------------------
All Construction Activities (Yrs 1-2)
------------------------------------------------------------------------
Safety Vessel........................... 2 114
Crew Transport Vessel................... 3 300
Jack-up/Lift Boat....................... 1 1
Supply Vessel........................... 1 10
Service Operation Vessel................ 1 6
Helicopter.............................. 2 350
------------------------------------------------------------------------
Operations Vessels (Yrs 3-5)
------------------------------------------------------------------------
Crew Transport Vessel................... 3 300
Service Operation Vessel................ 1 40
------------------------------------------------------------------------
Helicopters may be used during Sunrise Wind Farm construction and
operation phases for crew transfer activities to provide a reduction in
the overall transfer time as well as to reduce the number of vessels on
the water. Sunrise Wind estimates crew transfer time could be decreased
by 92 percent (16 to 30 minutes via a helicopter versus 3.5 to 6 hours
using a vessel). However, use of helicopters may be limited by many
factors, such as logistical constraints (e.g., ability to land on the
vessels) and weather conditions that affect flight operations.
Helicopter use also adds significant health, safety and environment
(HSE) risk to personnel and therefore, requires substantially more crew
training and additional safety procedures. These factors can result in
significant limitations to helicopter usage. The use of helicopters to
conduct crew transfers is likely to provide an overall benefit to
marine mammals in the form of reduced vessel activity.
Project-related aircraft would only occur at low altitudes over
water during takeoff and landing at an offshore location where one or
more vessels are located. Helicopters produce sounds that can be
audible to marine mammals; however, most sound energy from aircraft
reflects off the air-water interface as only sound radiated downward
within a 26-degree cone penetrates below the surface water (Urick
1972). Due to the intermittent nature and the small area potentially
ensonified by this sound source, Sunrise Wind did not request, and NMFS
is not proposing to authorize, take of marine mammals incidental to
helicopter flights; therefore, it will not be discussed further.
Seafloor Preparation
For export cable installation, seafloor preparation will include
required sand wave leveling, boulder clearance, and removal of any out
of service cables. Boulder clearance trials may be performed prior to
wide-scale seafloor preparation activities to evaluate efficacy of
boulder clearing techniques. Additionally, pre-lay grapnel runs (PLGR)
will be undertaken to remove any seafloor debris along the export cable
route. A specialized vessel will tow a grapnel rig along the centerline
of each cable to recover any debris to the deck for appropriate
licensed disposal ashore. Rock berm or concrete mattress separation
layers will also be installed at the eight known telecommunications
cables crossed by the SRWEC and/or inter-array cable (IAC) routes prior
to cable installation for both in-service
[[Page 9007]]
assets as well as out-of-service assets that cannot be safely removed
and pose a risk to the SRWEC or IAC.
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 prior to installation and will
involve a rock dumping vessel placing scour at each foundation
location.
Boulder clearance may be required in targeted locations to clear
boulders along the SRWEC, inter-array cable (IAC) routes, and/or
foundations prior to installation. Boulder removal can be performed
using a combination of methods to optimize clearance of boulder debris
of varying size and frequency. Removal is based on pre-surveys to
identify location, size, and density of boulders. The size of boulders
that can be relocated is dependent on a number of factors including the
boulder weight, dimensions, embedment, density and ground conditions.
Typically, boulders with dimensions less than 8 ft (2.5 m) can be
relocated with standard tools and equipment. Where required, Sunrise
Wind has assumed the route would be cleared of boulders up to 98 feet
(30-m) in width along the final SRWEC and IAC centerlines. Around the
foundations, Sunrise Wind assumes boulder clearance will occur within a
722-ft (220-m) radius centered on the foundations to ensure safe
foundation installation as well as safe vessel jack-up.
Boulder removal would occur prior to installation and would be
completed by a support vessel based on pre-construction surveys. A
boulder grab or a boulder plow may be used to complete boulder removal
prior to installation. A boulder grab involves a grab most likely
deployed from a dynamic positioning offshore support vessel being
lowered to the seabed over the targeted boulder. Once ``grabbed'', the
boulder is relocated away from the cable route and/or foundation
location. Boulder clearance using a boulder plow is completed by a
high-bollard pull vessel with a towed plow generally forming an
extended V-shaped configuration splaying from the rear of the main
chassis. The V-shaped configuration displaces any boulders to the
extremities of the plow, thus clearing the corridor. A tracked plow
with a front blade similar to a bulldozer may also be used to push
boulders away from the corridor.
Sand leveling (inclusive of leveling of sand accumulation areas)
may be required during seafloor preparation activities prior to
installation of the SRWEC. Two installation methods may be used to
complete sand leveling including Suction Hopper Dredging and controlled
flow excavation (CFE). The dredging technique consists of one or more
suction downpipes equipped with a seafloor drag head. The drag head is
towed over the sand wave by the vessel while a pump system sucks
fluidized sand into the vessel's storage hopper. Any sediment removed
would be relocated within the local sand wave field along the SRWEC and
IAC using continuous overflow from the vessel. Alternatively, the
removed sediment can be caught in the hopper storage and the vessel can
relocate to a designated storage or disposal area and either offload
material through a hatch in the vessel's hull or more carefully
position material subsea using a downpipe. CFE is a contactless
dredging tool, providing a method of clearing loose sediment below
submarine cables, enabling burial. CFE utilizes thrust to direct
waterflow into sediment, creating liquefaction and subsequent
dispersal. 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.
NMFS does not expect site preparation work, including boulder
removal and sand leveling, 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 SRWEC. Sound 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 the
high bollard pull vessel with a towed plow or a support vessel carrying
a boulder grab would be comparable to or less than the noise produced
by DP vessels, so impacts are also expected to be similar. Boulder
clearance is a discreet action occurring over a short duration
resulting in short term direct effects. Additionally, sound produced by
boulder clearance vessels and 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 Sunrise
Wind did not request, and NMFS does not propose to authorize, any takes
associated with seafloor preparation work and these activities are not
analyzed further in this document.
Fisheries and Benthic Monitoring
Fisheries and benthic monitoring surveys have been 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). Sunrise Wind
would conduct trawl surveys, acoustic telemetry studies, benthic
habitat monitoring using a remotely operated vehicle (ROV), video
surveillance, grab surveys, and Habcam surveys using towed video
surveillance. Because the gear types and equipment used for the
acoustic telemetry study, benthic habitat monitoring, and Habcam
surveys do not have components with which marine mammals are likely to
interact (i.e.,become entangled in or hooked by), these activities are
unlikely to have any impacts on marine mammals. Therefore, only trawl
surveys, in general, have the potential to result in harassment to
marine mammals. However, Sunrise 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, Sunrise Wind does not
anticipate, and NMFS is not proposing to authorize, take of marine
mammals incidental to research trawl surveys. Any lost gear associated
with the fishery surveys will be reported to the NOAA Greater Atlantic
Regional Fisheries Office Protected Resources Division as soon as
possible. Given no take is anticipated from these surveys, impacts from
fishery surveys will not be discussed further in this document.
[[Page 9008]]
Description of Marine Mammals in the Area of Specified Activities
Thirty-nine marine mammal species (comprising 40 stocks) have
geographic ranges within the western North Atlantic OCS (Hayes et al.,
2022). However, for reasons described below, Sunrise Wind has
requested, and NMFS proposes to authorize, take of only 16 species
(comprising 16 stocks) of marine mammals. Sections 3 and 4 of Sunrise
Wind's application summarize available information regarding status and
trends, distribution and habitat preferences, and behavior and life
history of the potentially affected species (Sunrise Wind, 2021). NMFS
fully considered all of this information, and we refer the reader to
these descriptions in the application, incorporated here by reference,
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 4 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 4 are the most recent available at the time of publication and
are available in NMFS' 2021 SARs (Hayes et al., 2022) 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 4--Marine Mammal Species Likely To Occur Near the Project Area That May Be Taken by Sunrise Wind's Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
North Atlantic right whale...... Eubalaena glacialis.... Western Atlantic....... E, D, Y 368 (0; 364; 2019) \5\ 0.7 7.7
Family Balaenopteridae (rorquals)
Blue whale...................... Balaenoptera musculus.. Western North Atlantic. E, D, Y UNK (UNK; 402; 1980- 0.8 0
2008).
Fin whale....................... Balaenoptera physalus.. Western North Atlantic. E, D, Y 6,802 (0.24; 5,573; 11 1.8
2016).
Sei whale....................... Balaenoptera borealis.. Nova Scotia............ E, D, Y 6,292 (1.02; 3,098; 6.2 0.8
2016).
Minke whale..................... Balaenoptera Canadian Eastern -, -, N 21,968 (0.31; 17,002; 170 10.6
acutorostrata. Coastal. 2016).
Humpback whale.................. Megaptera novaeangliae. Gulf of Maine.......... -, -, Y 1,396 (0; 1,380; 2016) 22 12.15
--------------------------------------------------------------------------------------------------------------------------------------------------------
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 Delphinidae
Atlantic white-sided dolphin.... Lagenorhynchus acutus.. Western North Atlantic. -, -, N 93,233 (0.71; 54,433; 544 27
2016).
Atlantic spotted dolphin........ Stenella frontalis..... Western North Atlantic. -, -, N 39,921 (0.27; 32,032; 320 0
2016).
Common bottlenose dolphin....... Tursiops truncatus..... Western North Atlantic -, -, N 62,851 (0.23; 51,914; 519 28
Offshore. 2016).
Long-finned pilot whales........ Globicephala melas..... Western North Atlantic. -, -, N 39,215 (0.3; 30,627; 306 29
2016).
Common dolphin (short-beaked)... Delphinus delphis...... Western North Atlantic. -, -, N 172,974 (0.21; 1,452 390
145,216; 2016).
Risso's dolphin................. Grampus griseus........ Western North Atlantic. -, -, N 35,215 (0.19; 30,051; 301 34
2016).
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena............... Gulf of Maine/Bay of -, -, N 95,543 (0.31; 74,034; 851 16
Fundy. 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals)
Gray seal \4\................... Halichoerus grypus..... Western North Atlantic. -, -, N 27,300 (0.22; 22,785; 1,389 4,453
2016).
[[Page 9009]]
Harbor seal..................... Phoca vitulina......... Western North Atlantic. -, -, N 61,336 (0.08; 57,637; 1,729 339
2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 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>
(Hayes et al., 2022). 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).
\4\ 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.
\5\ The values represent abundance estimates from NMFS 2021 Stock Assessment Report (Hayes et al., 2022). On Monday, October 24, 2022, the North
Atlantic Right Whale Consortium announced that the North Atlantic right whale population estimate for 2021 was 340 individuals. NMFS' website also
indicates that less than 350 animals remain (<a href="https://www.fisheries.noaa.gov/species/north-atlantic-right-whale">https://www.fisheries.noaa.gov/species/north-atlantic-right-whale</a>).
Of the 40 marine mammal species and/or stocks with geographic
ranges that include the western North Atlantic OCS (Table 5 in Sunrise
Wind ITA application), 24 are not expected to be present or are
considered rare or unexpected in the project area based on sighting and
distribution data; they are, therefore, not discussed further beyond
the explanation provided here. The following species are not expected
to occur in the project area due to the location of preferred habitat
outside the SRWF and SRWEC based on the best scientific information
available: Dwarf and pygmy sperm whales (Kogia sima and K breviceps),
northern bottlenose whale (hyperoodon ampullatus), cuvier's beaked
whale (Ziphius cavirostris), four species of Mesoplodont beaked whales
(Mesoplodon densitostris, M. europaeus, M. mirus, and M. bidens),
killer whale (Orcinus orca), false killer whale (Pseudorca crassidens),
pygmy killer whale (Feresa attenuate), short-finned pilot whale
(Globicephalus macrohynchus), melon-headed whale (Peponocephala
electra), Fraser's dolphin (Lagenodelphis hosei), white-beaked dolphin
(Lagenorhynchus albirotris), pantropical spotted dolphin (Stenella
attenuata), Clymene dolphin (Stenella clymene), striped dolphin
(Stenella coeruleoalba), spinner dolphin (Stenella longirostris),
rough-toothed dolphin (Steno bredanensis), and the northern migratory
coastal stock of common bottlenose dolphins (Tursiops truncatus
truncatus). The following species may occur in the project area but at
such low densities that take is not anticipated: hooded seal
(Cystophora cristata) and harp seal (Pagophilus groenlandica).
In addition, 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 and 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 SRWF is contained
within 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). The lack of detections of any of the 24 species listed above
during these surveys reinforces the fact that they are not expected to
occur in the project area. In addition, none of these species were
observed during HRG surveys conducted by Orsted in from 2018 to 2021.
As these species are not expected to occur in the project area during
the proposed activities, NMFS does not propose to authorize take of
these species, and they are not discussed further in this document.
As indicated above, all 16 species and stocks in Table 4 temporally
and spatially co-occur with the activity to the degree that take is
reasonably likely to occur. 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 Sunrise Wind's ITA application
(<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-sunrise-wind-llc-construction-and-operation-sunrise-wind">https://www.fisheries.noaa.gov/action/incidental-take-authorization-sunrise-wind-llc-construction-and-operation-sunrise-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.
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 November 7, 2022, seven UMEs are active. Five of these UMEs are
occurring along the U.S. Atlantic coast for various marine mammal
species; of these, the most relevant to the Sunrise Wind project are
the minke whale, 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 https://
www.fisheries.noaa.gov/national/marine-life-distress/
[[Page 9010]]
active-and-closed-unusual-mortality-events.
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. 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
La Brecque et al., 2015) that overlap spatially with the project area
are addressed in the species sections below.
North Atlantic Right Whale
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., 2021; Reed et al.,
2022). The Western Atlantic stock is considered depleted under the MMPA
(Hayes et al., 2022). There is a recovery plan (NOAA Fisheries, 2005)
for the North Atlantic right whale, and NMFS completed 5-year reviews
of the species in 2012 and 2017 (NOAA Fisheries, 2012; NOAA Fisheries,
2017). In February 2022, NMFS initiated a subsequent 5-year review
process (<a href="https://www.fisheries.noaa.gov/action/initiation-5-year-review-north-atlantic-right-whale">https://www.fisheries.noaa.gov/action/initiation-5-year-review-north-atlantic-right-whale</a>). 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
23.5percent 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 100
reproductively active females remain in the population. Presently, the
best available peer-reviewed population estimate for North Atlantic
right whales is 368 per the 2021 SARs (Hayes et al., 2022). As of this
writing, the draft 2022 SARs have yet to be released; however, as
reflected on NMFS' species web page, new estimates indicate that the
right whale population has continued to decline to fewer than 350
animals (<a href="https://www.fisheries.noaa.gov/species/north-atlantic-right-whale">https://www.fisheries.noaa.gov/species/north-atlantic-right-whale</a>). We note that the application of either abundance estimate in
our analysis would not change the estimated take of right whales or the
take NMFS has proposed to authorize as take estimates are based on the
habitat-density models (Roberts and Halpin 2022).
Since 2017, 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
January 12, 2023, there have been 35 confirmed mortalities (dead
stranded or floaters; 21 in Canada; 14 in the United States) and 22
seriously injured free-swimming whales for a total of 57 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 94. 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="http://www.fisheries.noaa.gov/national/marine-life-distress/2017-2021-north-atlantic-right-whale-unusual-mortality-event">www.fisheries.noaa.gov/national/marine-life-distress/2017-2021-north-atlantic-right-whale-unusual-mortality-event</a>.
North Atlantic right whale presence in the project area is
predominately seasonal; however, year-round occurrence is documented
with irregular occurrence during summer months (O'Brien et al., 2022,
Quintano-Rizzo et al., 2021). As a result of recent years of aerial
surveys and PAM deployments within the RI/MA WEA, we have confidence
that North Atlantic right whales are expected in the project area with
higher numbers of animals present in winter and spring followed by
decreasing abundance into summer and early fall (e.g., (O'Brien et al.,
2022, Quintano-Rizzo et al., 2021). 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., 2015). While the
project does not overlap previously identified critical feeding habitat
or a feeding BIA, it is located west of a more recently described
important feeding area south of Martha's Vineyard and Nantucket along
the western side of Nantucket Shoals. Finally, the project overlaps the
currently established November 1 through April 30th Block Island
Seasonal Management Area (SMA) (73 FR 60173, October 10, 2008) and the
proposed November 1 through May 30th Atlantic Seasonal Speed Zone (87
FR 46921, August 1, 2022), which may be used by North Atlantic right
whales for various activities, including feeding and migration. Due to
the current status of North Atlantic right whales and the 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.
Southern New England and New York waters are both a migratory
corridor in the spring and early winter and a primary feeding habitat
for North Atlantic right whales during late winter through spring.
North Atlantic 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;
[[Page 9011]]
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; Quintano-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 to
the east of the SRWF and SRWEC corridor (Stone et al., 2017; Mayo et
al., 2018; Ganley et al., 2019; Record et al., 2019; Meyer-Gutbrod et
al., 2021). Pendleton et al. (2022) found that peak use of North
Atlantic right whale foraging habitat in Cape Cod Bay has shifted over
the past 20 years to later in the spring, likely due to variations in
seasonal conditions. However, initial sightings of individual North
Atlantic right whales in Cape Cod Bay have started earlier, indicating
that they may be using regional water temperature as a cue for
migratory movements between habitats (Ganley et al. 2022). North
Atlantic right whales have recently been observed feeding year-round in
the region south of Martha's Vineyard and Nantucket (Quintana-Rizzo et
al., 2021) with larger numbers in this area in the winter making it the
only known winter foraging habitat for the species (Leiter et al.,
2017). North Atlantic right whale use of habitats, such as in the Gulf
of St. Lawrence and East Coast mid-Atlantic waters of the United
States., have also increased over time (Davis et al., 2017; Davis and
Brillant, 2019; Crowe et al., 2021; Quintana-Rizzo et al., 2021).
Simard et al. (2019) documented the presence of North Atlantic right
whales in the southern Gulf of St. Lawrence foraging habitat from late
April through mid-January annually from 2010-2018 using passive
acoustics with occurrences peaking in the area from August through
November each year (Simard et al., 2019). Observations of these
transitions in North Atlantic right whale habitat use, variability in
seasonal presence in identified core habitats, and utilization of
habitat outside of previously focused survey effort prompted the
formation of a NMFS' Expert Working Group, which identified current
data collection efforts, data gaps, and provided recommendations for
future survey and research efforts (Oleson et al., 2020).
Around November, a portion of the North Atlantic right whale
population (including pregnant females) typically departs the feeding
grounds in the North Atlantic, move south along the migratory corridor
BIA, including through the project area, to North Atlantic 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 (Gowen et al., 2019).
Within the project area, North Atlantic right whales have primarily
been observed during the winter and spring seasons through recent
visual surveys (Kraus et al., 2016; Quintana-Rizzo et al., 2021).
During aerial surveys conducted in the RI/MA and MA WEAs from 2011-
2015, the highest number of North Atlantic right whale sightings
occurred in March (n=21), with sightings also occurring in December
(n=4), January (n=7), February (n=14), and April (n=14), and no
sightings in any other months (Kraus et al., 2016). There was not
significant variability in sighting rate among years, indicating
consistent annual seasonal use of the area by North Atlantic right
whales. Despite the lack of visual detection, North Atlantic right
whales were acoustically detected in 30 out of the 36 recorded months
(Kraus et al., 2016). Since 2017, whales have been sighted in the
southern New England area nearly every month with peak sighting rates
between late winter and spring. 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 (Quintano-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
(75percent array-days, n = 193), and summer had the lowest presence
(10percent array-days, n = 27). Spring and autumn were similar, where
45percent (n = 117) and 51percent (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 broadscale 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.
While density data from Roberts et al. (2022) confirm that the
highest average density of North Atlantic right whales in the project
area (both the lease area and SRWEC corridor) occurs in May (0.0018
whales/km\2\), which aligns with available sighting and acoustic data,
it is clear that that habitat use is changing and North Atlantic right
whales are present to some degree in or near the project area
throughout the year, most notably south of Martha's Vineyard and
Nantucket Islands (Leiter et al., 2017; Stone et al., 2017; Oleson et
al., 2020, Quintano-Rizzo et al., 2021). Since 2010, North Atlantic
right whale abundances have increased in Southern New England waters,
south of Martha's Vineyard and Nantucket Islands. O'Brien et al. (2022)
detected significant increases in North Atlantic right whale abundance
during winter and spring seasons from 2013-2019 likely due to changes
in prey availability. Since 2017, North Atlantic right whales were also
detected in small numbers during summer and fall, suggesting that
southern New England waters provide year-round habitat for North
Atlantic right whales (O'Brien et al., 2022).
NMFS' regulations at 50 CFR 224.105 designate nearshore waters of
the Mid-Atlantic Bight as the Mid-Atlantic U.S. SMAs for North Atlantic
right whales in 2008. These specific SMAs were
[[Page 9012]]
developed to reduce the threat of collisions between ships and North
Atlantic right whales around their migratory route and calving grounds.
As mentioned previously, the Block Island SMA overlaps spatially with
the proposed project area (<a href="https://apps-nefsc.fisheries.noaa.gov/psb/surveys/MapperiframeWithText.html">https://apps-nefsc.fisheries.noaa.gov/psb/surveys/MapperiframeWithText.html</a>). The 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).
Humpback Whale
Humpback whales were listed as endangered under the Endangered
Species Conservation Act (ESCA) in June 1970. In 1973, the ESA replaced
the ESCA, and humpbacks continued to 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 4 DPSs as endangered and 1 DPS as threatened
(81 FR 62259, September 8, 2016). The remaining nine DPSs were not
listed. The West Indies DPS, which is not listed under the ESA, is the
only DPS of humpback whales that is expected to occur in the project
area. Bettridge et al. (2015) estimated the size of the West Indies DPS
population at 12,312 (95 percent 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 (LeBrecque 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 January 12, 2023, 174 humpback whales have stranded as part of
this UME. Partial or full necropsy examinations have been conducted on
approximately half of the 161 known cases (as of November 7, 2022). Of
the whales examined, about 50 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.
NOAA is consulting with researchers that are conducting studies on the
humpback whale populations, and these efforts may provide information
on changes in whale distribution and habitat use that could provide
additional insight into how these vessel interactions occurred. More
information is available at: <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast">https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast</a>.
Fin Whale
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
indicated that this species was present in the RI/MA & MA WEAs during
all months of the year.
New England waters represent a major feeding ground for fin whales.
Almost the entire lease area (351 km\2\) overlaps approximately 12
percent of a relatively small 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 Whale
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 (LeBrecque 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
[[Page 9013]]
may exist to the east of the proposed project area as minke whales may
trac warmer waters along the continental shelf while migrating (Risch
et al., 2014).
Since January 2017, elevated minke whale mortalities detected along
the Atlantic coast from Maine through South Carolina resulted in the
declaration of a UME. As of January 12 2023, a total of 136 minke
whales have stranded 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>.
Phocid Seals
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
Sunrise Wind project area, the populations affected by the UME are the
same as those potentially affected by the project.
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="http://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along">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 5.
Table 5--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Generalized hearing range
Hearing group *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales). 7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
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) (true 50 Hz to 86 kHz.
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.
Sixteen marine mammal species (14 cetacean species (6 mysticetes and 8
odontocetes) and 2 pinniped species (both phocid)) have the reasonable
potential to co-occur with the proposed project activities (Table 4).
NMFS notes that in 2019, 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. (2019) are identical to NMFS 2018 Revised Technical
Guidance). When NMFS updates our Technical Guidance, we will be
adopting the updated Southall et al. (2019) hearing group
classification.
Potential Effects of Specified Activities to 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
[[Page 9014]]
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 Specified Activities section). Here, the potential
effects of sound on marine mammals are discussed.
Sunrise Wind has requested authorization to take marine mammals
incidental to construction activities associated with in the Sunrise
Wind project area. In the ITA application, Sunrise Wind presented
analyses of potential impacts to marine mammals from use of acoustic
and explosive sources. NMFS carefully reviewed the information provided
by Sunrise Wind and independently reviewed applicable scientific
research and literature and other information to evaluate the potential
effects of Sunrise Wind's activities on marine mammals.
The proposed activities would result in placement of up to 95
permanent foundations (94 WTGs and 1 OCS-DC) and a temporary casing
pipe in the marine environment. Up to three UXO/MEC detonations may
occur during construction if any found UXO/MEC cannot be 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 in 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, e.g., 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.
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 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.
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. Sounds are
typically classified by their spectral and temporal properties.
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 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,
[[Page 9015]]
2019) for an in-depth discussion of these concepts. Impulsive sound
sources (e.g., airguns, explosions, gunshots, sonic booms, impact pile
driving) produce signals that are brief (typically considered to be
less than 1 second), broadband, atonal transients (ANSI, 1986, 2005;
Harris, 1998; NIOSH, 1998; 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 (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 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. Underwater ambient sound in the Atlantic Ocean southeast of
Rhode Island comprises sounds produced by a number of natural and
anthropogenic sources. Human-generated sound is a significant
contributor to the acoustic environment in the project location.
Potential Effects of Underwater Sound on Marine Mammals and Their
Habitat
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 Sunrise Wind 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). Potential effects from explosive sound sources
can range in severity from behavioral disturbance or tactile perception
to physical discomfort, slight injury of the internal organs and the
auditory system, or mortality (Yelverton et al., 1973).
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 Sunrise 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 animale) 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
[[Page 9016]]
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 Sunrise
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).
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., 2019).
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., 2019).
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., 2019). 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., 2019). 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 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 (Neophocoena 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., 2019). 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. (2019), 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,b,c, 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 Disturbance
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
[[Page 9017]]
to anthropogenic sound was first conducted by Richardson (1995). More
recent reviews (Nowacek et al., 2007; DeRuiter et al., 2012 and 2013;
Ellison et al., 2012; Gomez et al., 2016) 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. 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., 2019). 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. (2013) 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. (2013) 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 MF
sonar and found that whales responded strongly at low received levels
(89-127 dB re 1[micro]Pa) by ceasing normal fluking and echolocation,
swimming rapidly away, and extending both dive duration and subsequent
non-foraging intervals when the sound source was 3.4-9.5 km 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; Dunlop et
al., 2017b; Falcone et al., 2017; Dunlop et al., 2018; Southall et al.,
2019).
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 sixfold 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.
[[Page 9018]]
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
or 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., 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; Malme et al., 1984). 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 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 (Haleters et al., 2015; Lucke et al., 2012; D[auml]hne et al.,
2013; Tougaard et al., 2009; Bailey et al., 2010.)
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 (Carroll et al., 2010; Hamre et al., 2011; Hastie et al., 2015;
Russell et al., 2016; Brasseur et al., 2010). 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 Sunrise Wind proposes to install.
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 New York. However, we do not anticipate
any greater severity of response due to harbor porpoise and harbor seal
habitat use off New York or population level consequences similar to
European findings. In many cases, harbor porpoises and harbor seals are
resident
[[Page 9019]]
to the areas where European wind farms have been constructed. However,
off New York, harbor porpoises are transient (with higher abundances in
winter when impact pile driving 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. As previously noted, the
literature on marine mammal responses to offshore wind farms is limited
to species which are known to be more behaviorally sensitive to
auditory stimuli than the other species that occur in the project area.
Therefore, the documented behavioral responses of harbor porpoises and
harbor seals to pile driving in Europe should be considered as a worst-
case scenario in terms of the potential responses among all marine
mammals to offshore pile driving, and these responses cannot reliably
predict the responses that will occur in other marine mammal species.
Some avoidance behavior of other marine mammal species has been
documented to be dependent on distance from the source in response to
playbacks. 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 the 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). Sunrise
Wind does not anticipate, and NMFS is not proposing to authorize, take
of beaked whales and, moreover, the sounds produced by Sunrise 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 consequence of behavioral avoidance results in 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).
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.
Flight Response
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). A flight
response may also be possible in response to UXO/MEC detonation;
however, given a detonation is instantaneous, only one detonation would
occur on a given day,
[[Page 9020]]
only 3 detonations may occur over 5 years, and the proposed mitigation
and monitoring would result in any animals being far from the
detonation (i.e., the clearance zone extends 10 km from the UXO/MEC
location), any flight response would be spatially and temporally
limited.
Alteration of 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, 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 and the type and magnitude of the response.
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 North Atlantic right whale social sounds or vessel noise,
highlighting the importance of the sound characteristics in producing a
behavioral reaction. All signals were relatively brief in duration,
similar to the proposed Sunrise construction and HRG activities.
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 any response
to proposed pile driving activities. 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 appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation as well as
differences in species sensitivity are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al.; 2004; Madsen et al., 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.,
2013; Farmer et al., 2018; Pirotta et al., 2018; Southall et al., 2019;
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 behavior prior to,
during, and following exposure to air gun 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 air guns had ceased firing. The remaining
whales continued to execute foraging dives throughout exposure;
however, swimming movements during foraging dives were six 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 the proposed
construction and HRG activities exceed the source levels of the signals
described by Nowacek et al. (2004) and Croll et al. (2001), yet noise
generated by Sunrise Wind's activities would 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
[[Page 9021]]
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., 2019b).
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 this is the case,
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).
Breathing
Respiration naturally varies with different behaviors and
variations in respiration rate as a function of acoustic exposure can
be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Mean exhalation rates of gray whales at rest and while
diving were found to be unaffected by seismic surveys conducted
adjacent to the whale feeding grounds (Gailey et al., 2007). Studies
with captive harbor porpoises show increased respiration rates upon
introduction of acoustic alarms (Kastelein et al., 2001; Kastelein et
al., 2006a) and emissions for underwater data transmission (Kastelein
et al., 2005). However, exposure of the same acoustic alarm to a
striped dolphin under the same conditions did not elicit a response
(Kastelein et al., 2006a), again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure.
Vocalizations (Also see the Auditory Masking Section)
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 (also see the Potential Effects of
Behavioral Disturbance on Marine Mammal Fitness section) 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 in the Auditory Masking section
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 air
gun signals were detectable before ultimately decreasing calling rates
at higher received levels.
Orientation
A shift in an animal's resting state or an attentional change via
an orienting response represent behaviors that would be considered mild
disruptions if occurring alone. As previously mentioned, the responses
may co-occur with other behaviors; for instance, an animal may
initially orient toward a sound source and then move away from it.
Thus, any orienting response should be considered in context of other
reactions that may occur.
Habituation and Sensitization
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. It is important to note that
habituation is appropriately considered as a ``progressive reduction in
response to stimuli that are perceived as neither aversive nor
beneficial,'' rather than as, more generally, moderation in response to
human disturbance having a neutral or positive outcome (Bejder et al.,
2009). The opposite process is sensitization, when an unpleasant
experience leads to subsequent responses, often in the form of
avoidance, at a lower level of exposure. Both habituation and
sensitization require an ongoing learning process. As noted, behavioral
state may affect the type of response. For example, animals that are
resting may show greater behavioral change in response to disturbing
sound levels than animals that are highly motivated to remain in an
area for feeding (Richardson et al., 1995; NRC, 2003; Wartzok et al.,
2003; Southall et al., 2019b). Controlled experiments with captive
marine mammals have shown pronounced behavioral reactions, including
avoidance of loud sound sources (e.g., Ridgway et al., 1997; Finneran
et al., 2003; Houser et al. (2013a, b); Kastelein et al. (2018).
Observed responses of wild marine mammals to loud impulsive sound
[[Page 9022]]
sources (typically airguns or acoustic harassment devices) have been
varied but often consist of avoidance behavior or other behavioral
changes suggesting discomfort (Morton and Symonds, 2002; see also
Richardson et al., 1995; Nowacek et al., 2007; Tougaard et al., 2009;
Brandt et al., 2011, Brandt et al., 2012, D[auml]hne et al., 2013;
Brandt et al., 2014; Russell et al., 2016; Brandt et al., 2018).
However, many delphinids approach low-frequency airgun source vessels
with no apparent discomfort or obvious behavioral change (e.g.,
Barkaszi et al., 2012), indicating the importance of frequency output
in relation to the species' hearing sensitivity.
Stress Response
An animal's perception of a threat may be sufficient to trigger
stress responses consisting of some combination of behavioral
responses, autonomic nervous system responses, neuroendocrine
responses, or immune responses (e.g., Seyle, 1950; Moberg, 2000). In
many cases, an animal's first and sometimes most economical (in terms
of energetic costs) response is behavioral avoidance of the potential
stressor. Autonomic nervous system responses to stress typically
involve changes in heart rate, blood pressure, and gastrointestinal
activity. These responses have a relatively short duration and may or
may not have a significant long-term effect on an animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha,
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Lusseau and Bejder, 2007; Romano et al., 2002a; Rolland et al.,
2012). For example, Rolland et al. (2012) found that noise reduction
from reduced ship traffic in the Bay of Fundy was associated with
decreased stress in North Atlantic right whales. Lusseau and Bejder
(2007) present data from three long-term studies illustrating the
connections between disturbance from whale-watching boats and
population-level effects in cetaceans. In Shark Bay, Australia, the
abundance of bottlenose dolphins was compared within adjacent control
and tourism sites over three consecutive 4.5-year periods of increasing
tourism levels. Between the second and third time periods, in which
tourism doubled, dolphin abundance decreased by 15 percent in the
tourism area and did not change significantly in the control area. In
Fiordland, New Zealand, two populations (Milford and Doubtful Sounds)
of bottlenose dolphins with tourism levels that differed by a factor of
seven were observed and significant increases in traveling time and
decreases in resting time were documented for both. Consistent short-
term avoidance strategies were observed in response to tour boats until
a threshold of disturbance was reached (average 68 minutes between
interactions), after which the response switched to a longer-term
habitat displacement strategy. For one population, tourism only
occurred in a part of the home range. However, tourism occurred
throughout the home range of the Doubtful Sound population and once
boat traffic increased beyond the 68-minute threshold (resulting in
abandonment of their home range/preferred habitat), reproductive
success drastically decreased (increased stillbirths) and abundance
decreased significantly (from 67 to 56 individuals in a short period).
These and other studies lead to a reasonable expectation that some
marine mammals will experience physiological stress responses upon
exposure to acoustic stressors and that it is possible that some of
these would be classified as ``distress.'' In addition, any animal
experiencing TTS would likely also experience stress responses (NRC,
2003, 2017).
Auditory Masking
Sound can disrupt behavior through masking or interfering with an
animal's ability to detect, recognize, or discriminate between acoustic
signals of interest (e.g., those used for intraspecific communication
and social interactions, prey detection, predator avoidance, 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, 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, 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 Level B harassment when disrupting or altering critical
behaviors. It is important to distinguish TTS and
[[Page 9023]]
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., 2016) 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).
High-frequency sounds may mask the echolocation calls of toothed
whales. 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 intensi
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