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Proposed Rule2023-07417

Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Empire Wind Project, Offshore New York

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Published

April 13, 2023

Issuing agencies

Commerce DepartmentNational Oceanic and Atmospheric Administration

Abstract

NMFS has received a request from Empire Offshore Wind, LLC (Empire Wind), a 50/50 joint venture between Equinor and BP p.l.c., for Incidental Take Regulations (ITR) and an associated Letter of Authorization (LOA). 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 (2024- 2029) incidental to construction of the Empire Wind Project offshore New York in a designated lease area on the Outer Continental Shelf (OCS-A-512). Project activities likely to result in incidental take include impact pile driving, vibratory pile driving and removal, and site assessment surveys using high-resolution geophysical (HRG) equipment. As required by the Marine Mammal Protection Act (MMPA), NMFS requests comments on its proposed rule. NMFS will consider public comments prior to making any final decision on the promulgation of the requested incidental take authorization (ITA) and issuance of the LOA; agency responses to public comments will be summarized in the final notice of our decision. The proposed regulations, if issued, would be effective January 22, 2024, through January 21, 2029.

Full Text

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[Federal Register Volume 88, Number 71 (Thursday, April 13, 2023)]
[Proposed Rules]
[Pages 22696-22787]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-07417]

[[Page 22695]]

Vol. 88

Thursday,

No. 71

April 13, 2023

Part III

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 Empire Wind Project, Offshore New
York; Proposed Rule

Federal Register / Vol. 88, No. 71 / Thursday, April 13, 2023 /
Proposed Rules

[[Page 22696]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 230404-0092]
RIN 0648-BL97

Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Empire Wind 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 Empire Offshore Wind, LLC
(Empire Wind), a 50/50 joint venture between Equinor and BP p.l.c., for
Incidental Take Regulations (ITR) and an associated Letter of
Authorization (LOA). 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 (2024-
2029) incidental to construction of the Empire Wind Project offshore
New York in a designated lease area on the Outer Continental Shelf
(OCS-A-512). Project activities likely to result in incidental take
include impact pile driving, vibratory pile driving and removal, and
site assessment surveys using high-resolution geophysical (HRG)
equipment. As required by the Marine Mammal Protection Act (MMPA), NMFS
requests comments on its proposed rule. NMFS will consider public
comments prior to making any final decision on the promulgation of the
requested incidental take authorization (ITA) and issuance of the LOA;
agency responses to public comments will be summarized in the final
notice of our decision. The proposed regulations, if issued, would be
effective January 22, 2024, through January 21, 2029.

DATES: Comments and information must be received no later than May 15,
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-
0053 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: Robert Pauline, Office of Protected
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

A copy of Empire 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 issued, would provide a framework under
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 Empire Wind Project within the Bureau of Ocean Energy Management
(BOEM) Renewable Energy Lease Area OCS-A 512 and along export cable
corridors to two landfall locations in New York. NMFS received a
request from Empire Wind requesting 5-year regulations and a LOA that
would authorize take of individuals of 17 species of marine mammals
(two species by Level A harassment and Level B harassment and 17
species by Level B harassment only) incidental to Empire Wind's
construction activities. No mortality or serious injury is anticipated
or proposed for authorization. Please see the Estimated Take of Marine
Mammals section 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 (when required), 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 this rule containing five-year regulations
and associated LOA. As directed by this legal authority, this proposed
rule also establishes required mitigation, monitoring, and reporting
requirements for Empire Wind's activities.

Summary of Major Provisions Within the Proposed Rule

The major provisions within this proposed rule are as follows:
<bullet> Establish 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> Require both visual and passive acoustic monitoring by
trained, NOAA Fisheries-approved Protected Species Observers (PSOs) and
Passive Acoustic Monitoring (PAM) operators before, during, and after
the in-water construction activities;
<bullet> Require the use of sound attenuation device(s) during all
impact pile driving to reduce noise levels;
<bullet> Delay the start of pile driving if a North Atlantic right
whale is observed at any distance by PSOs or acoustically detected;
<bullet> Delay the start of pile driving if other marine mammals
are observed entering or within their respective clearance zones;

[[Page 22697]]

<bullet> Shut down pile driving (if feasible) if a North Atlantic
right whale is observed or if other marine mammals enter their
respective shut down zones;
<bullet> Implement sound field verification requirements during
impact pile driving to measure in situ noise levels for comparison
against the model results;
<bullet> Implement soft-starts for impact pile driving and use the
least hammer energy possible;
<bullet> Require PSOs to continue to monitor for the presence of
marine mammals for 30 minutes after any impact pile driving occurs;
<bullet> Implement ramp-up for HRG site characterization survey
equipment;
<bullet> Increase awareness of North Atlantic right whale presence
through monitoring of the appropriate networks and Channel 16, as well
as reporting any sightings to the sighting network;
<bullet> Implement various vessel strike avoidance measures; and
<bullet> Implement 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 CF 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 review our proposed action (i.e., promulgation
of regulations and subsequent issuance of a 5-year LOA) and
alternatives with respect to potential impacts on the human
environment.
Accordingly, NMFS proposes to adopt the Bureau of Ocean Energy
Management's (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 (Empire Wind Draft
Environmental Impact Statement (DEIS) for Commercial Wind Lease OCS-A
512) was made available for public comment on November 18, 2022 (87 FR
69330), beginning the 60-day comment period ending on January 17, 2023.
The draft EIS can be found at: <a href="https://www.boem.gov/renewable-energy/state-activities/empire-wind">https://www.boem.gov/renewable-energy/state-activities/empire-wind</a>. Additionally, BOEM held three virtual
public hearings on December 7, 2022, December 13, 2022 and December 15,
2022.
Information contained within Empire Wind's ITA application and this
proposed rule collectively 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 ITA 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).
Empire Wind's proposed project is listed on the Permitting
Dashboard (<a href="https://www.permits.performance.gov/">https://www.permits.performance.gov/</a>), 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/empire-wind-energy-project">https://www.permits.performance.gov/permitting-project/empire-wind-energy-project</a>.

Summary of Request

On December 7, 2021, Empire 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 Empire Wind Project offshore of New York in
BOEM Lease Area OCS-A-0512. Empire Wind's request is for the
incidental, but not intentional, taking of a small number of 17 marine
mammal species (comprising 18 stocks) by Level B harassment (for all 18
stocks) and by Level A harassment (for two species or stocks). Neither
Empire Wind, nor NMFS, expect serious injury or mortality to result
from the specified activities nor is any proposed for authorization.
In response to our comments, and following extensive information
exchange with NMFS, Empire Wind submitted a final, revised application
on July 28, 2022, that NMFS deemed adequate and complete on August 11,
2022. In June 2022, new scientific information was released regarding
marine mammal densities (Robert and Halpin, 2022). In response, Empire
Wind submitted a final addendum to the application on January 25, 2023,
which included revised marine mammal densities and take estimates based
on Roberts and Halpin 2022. The addendum also identified a revision to
the density calculation methodology. Both of these revisions were
recommended by NMFS. Empire Wind requests the regulations and
subsequent LOA be valid for 5 years beginning in the first quarter of
2024 (January 22) through the first quarter of 2029 (January 21).
Neither Empire Wind nor NMFS expects serious injury or mortality to
result from the specified activities. Empire Wind's complete
application and associated addendum are available on NMFS' website at:
<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-empire-offshore-wind-llc-construction-empire-wind-project-ew1?check_logged_in=1">https://www.fisheries.noaa.gov/action/incidental-take-authorization-empire-offshore-wind-llc-construction-empire-wind-project-ew1?check_logged_in=1</a>.
On September 9, 2022, NMFS published a notice of receipt (NOR) of
the application in the Federal Register (87 FR 55409), requesting
comments and soliciting information related to Empire Wind's request
during a 30-day public comment period. During the NOR public comment
period, NMFS received comment letters from an environmental non-
governmental organization (Responsible Offshore Development Alliance)
and a corporate entity (Allco Renewable Energy Limited). NMFS has
reviewed all submitted material and has taken these into consideration
during the drafting of this proposed rulemaking.
NMFS previously issued three Incidental Harassment Authorizations
(IHAs) to Equinor and its predecessors for the taking of marine mammals
incidental to marine site characterization surveys (using HRG
equipment) of the Empire Wind Lease Area (OCS-A 0512) and cable
corridors (these were not issued to Empire Wind as this subsidiary of
Equinor had not yet been established). On April 24, 2018, NMFS issued
an IHA to Statoil Wind U.S. LLC, effective from April 24, 2018, through
April 23, 2019 (83 FR 19532; May 3, 2018) which included Lease

[[Page 22698]]

Area OCS-A 512 and associated cable route corridors. Since the initial
IHA was issued, Statoil Wind U.S. LLC changed the name under which the
company operates to Equinor. A renewal IHA was issued to Equinor and
was effective from April 25, 2019 through April 24, 2020 (84 FR 18801)
which covered the same area. A new IHA was issued to Equinor on
September 25, 2020 (85 FR 60424) and was effective from September 20,
2020, to September 19, 2021 which included OCS-A 512 and associated
cable routes.
To date, Equinor, the parent company of Empire Wind, has complied
with all IHA requirements (e.g., mitigation, monitoring, and reporting)
of these IHAs. Information regarding Equinor's take estimates and
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 to endangered right whales
from vessel collisions, which are a leading cause of the species'
decline and a primary factor in an ongoing Unusual Mortality Event (87
FR 46921). Should a final vessel speed rule be issued and become
effective during the effective period of this ITA (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 Empire Wind if the measures in the speed rule
were to supersede any of the measures in the MMPA authorization such
that they were not longer required.

Description of the Specified Activity

Overview

Empire Wind proposes to construct and operate two offshore wind
projects within OCS-A 0512: Empire Wind 1 (EW 1; western portion of
Lease Area) and Empire Wind 2 (EW 2; eastern portion of Lease Area)
(Figure 1). Combined the two projects would produce a total of
approximately 2,076 megawatts (MW) of renewable energy to New York. EW
1 (816 MW) and EW 2 (1,260 MW) will be electrically isolated and
independent of each other and each will be connected to their own
points of interconnection (POIs) via individual submarine export cable
routes.
Empire Wind's project would consist of several different types of
permanent offshore infrastructure, including wind turbine generators
(WTGs) and associated foundations, offshore substations (OSSs), inter-
array cables, submarine export cables and scour protection.
Specifically, activities to construct the project include the
installation of up to 147 WTGs and two OSSs by impact pile driving
(total of 149 foundations). Additional activities would include cable
installation, site preparation activities (e.g., dredging), HRG
surveys, installation of cofferdams or casing pipes supported by goal
post piles, removal of berthing piles and performing marina bulkhead
work; and conducting several types of fishery and ecological monitoring
surveys. Multiple vessels would transit within the project area and
between ports and the wind farm to perform the work and transport crew,
supplies, and materials. All offshore cables will connect to onshore
export cables, substations, and grid connections on Long Island and
Brooklyn, New York. Marine mammals exposed to elevated noise levels
during impact and vibratory pile driving or site characterization
surveys may be taken by Level A harassment and/or Level B harassment
depending on the specified activity.
Activities Not Considered in Empire Wind's Request for Authorization
During construction, Empire Wind will receive equipment and
materials to be staged and loaded onto installation vessels at one or
more existing third-party port facilities. Empire Wind not yet
finalized the selection of all facilities, although they will include
the South Brooklyn Marine Terminal (SBMT) in Brooklyn, New York. SBMT
has been selected as the location for export cable landfall and the
onshore substation for EW 1. Empire Wind also has leased portions of
SBMT for EW 1 and EW 2 for laydown and staging of wind turbine blades,
turbines, and nacelles; foundation transition pieces; or other facility
parts during construction of the offshore wind farm.
The final port selection(s) for staging and construction will be
determined based upon whether the ports are able to accommodate Empire
Wind's schedule, workforce and equipment needs. Any port improvement
construction activities to facilitate laydown and staging would be
conducted by a separate entity and would serve the broader offshore
wind industry in addition to the Empire Wind Project. Empire Wind
would, therefore, not be the applicant for the authorization of marine
mammal take incidental to these activities if an authorization for
incidental take is warranted, and these activities are not analyzed
further in this proposed rule.
Empire Wind is not planning on detonating any unexploded ordnance
(UXO) or munitions and explosives of concern (MEC) during the effective
period of the proposed rule, if issued. Hence, Empire Wind did not
analyze or request take associated with this activity as it would not
occur. Other means of removing UXO/MEC may occur (e.g., lift and
shift). As UXO/MEC detonation would not occur, it is not discussed
further in this analysis.

Dates and Duration

Empire Wind anticipates that activities with the potential to
result in harassment of marine mammals would occur throughout all five
years of the proposed regulations which, if promulgated, would be
effective from January 22, 2024 through January 21, 2029.
The estimated schedule, including dates and duration, for various
activities is provided in Table 1. Detailed information about the
activities themselves may be found in the Detailed Description of the
Specific Activity subsection.
Empire Wind anticipates that 96 WTG monopiles will be installed in
2025 and the remaining 51 WTG monopiles will be installed in 2026.
Specifically, installation of WTG monopiles is expected to begin in the
second quarter of 2025 and end in the fourth quarter of 2025 for both
EW 1 and EW 2. Installation of monopile foundations would resume in EW
2 in the second quarter of 2026 and end in the fourth quarter of that
year. OSS foundation installation would occur in 2025 for both EW 1 and
EW 2; however, topside work on the EW 2 OSS would occur in 2026 and
2025 and 2026 (EW 2). While Empire Wind currently anticipates adherence
to this schedule, it is possible

[[Page 22699]]

that foundations could be installed in later time periods (but within
the 5-year effective period of the LOA) should permitting or scheduling
delays occur).
Installation of foundation piles would not occur from January 1-
April 30 in any given year. In addition, impact pile driving is not
planned from December 1 through December 31 but could only occur if
unanticipated delays due to weather or technical problems arise that
necessitate extending pile driving into December in which case Empire
Wind would notify NOAA Fisheries and BOEM in advance writing by
September 1 that circumstances are expected to necessitate pile driving
in December. Given this uncertainty, Empire Wind has included December
into its analysis to be precautionary; however, pile driving is
currently planned for May through November. Each monopile pile will
require up to 3.5 hours of impact pile driving and each pin pile will
require up to 5 hours of impact pile driving.
Either cofferdams or casing pipe and goal post installation may
occur as part of cable landfall activities, but not both. EW 1 cable
landfall work would occur sometime between Q1 to Q4 in 2024 while EW 2
cable landfall work would occur sometime between Q1 2024-Q4 2025.
Depending on the construction method chosen, each cable landfall site
would require 7-30 days of work. Exact dates and durations could shift
depending on factors such as weather delays, procurement, or
contracting issues
The anticipated activity schedule for all activities is shown in
Table 1. Empire Wind anticipates that WTGs in EW 1 would become
operational late in Q2 or early Q3 in 2026 while those in EW 2 would
become operational in Q4 of 2027. Turbines would be commissioned
individually by personnel on location, so the number of commissioning
teams would dictate how quickly turbines would become operational.

Table 1--Estimated Activity Schedule To Construct and Operate the Empire Wind Project
----------------------------------------------------------------------------------------------------------------
Project activity Expected timing EW 1 Expected timing EW 2
----------------------------------------------------------------------------------------------------------------
Submarine Export Cables............ Q3 2024; Q3 2025........... Q3-Q4 2025.
Offshore Substation Jacket Q2 \1\-Q4 2025............. Q2 \1\-Q4 2025; Q2 \1\-Q4 2026. \2\
Foundation and Topside.
Monopile Foundation Installation... Q2 \1\-Q4 2025............. Q2 \1\-Q4 2025; Q2 \1\-Q4 2026.
WTG Installation................... Q4 2025-Q2 2026............ Q4 2026-Q3 2027.
Interarray Cables.................. Q2-Q4 2025................. Q2-Q3 2026.
HRG Surveys........................ Q1 2024-Q4 2028............ Q1 2024-Q4 2028.
Cable Landfall Construction........ Q1-Q4 2024 \3\............. Q1 2024-Q4 2025. \3\
Marina Activities.................. n/a........................ Q1-Q4 2024.
Barnum Channel Cable Bridge n/a........................ Q4 2024-Q2 2025.
Construction.
----------------------------------------------------------------------------------------------------------------
Note: Project activities are anticipated to start no earlier than Q1 2024.
\1\ Impact driving of foundation piles is prohibited between January 1 and April 30. During Q2 such activities
could not start until May 1.
\2\ EW 2 OSS jacket installation is planned for 2025, only EW 2 topside work is planned for 2026.
\3\ While cable landfall construction could occur at any time during the time period identified would only occur
for approximately 30 days.

Specific Geographic Region

Empire Wind would conduct activities in state waters and Federal
waters within the designated Lease Area OCS-A 0512 (which covers
approximately 321 square kilometers (km\2\; 79,350 acres) and New York
state waters (See Figure 1)). The Lease Area is located in the New York
Bight, approximately 14 miles (mi; 12 nautical miles (nm); 22 km) south
of Long Island, New York, and 19.5 mi (16.9 nm; 31.4 km) east of Long
Branch, New Jersey. The New York Bight is a section of the northwestern
Atlantic Ocean that extends along the United States East Coast between
Cape May, New Jersey in the southwest, to Montauk Point, New York in
the northeast. It includes the waters over the continental shelf and
offshore to the shelf break. It is part of the larger Mid-Atlantic
Bight, which spans from Cape Hatteras, North Carolina to Cape Cod,
Massachusetts. A number of estuaries drain into the New York Bight and
provide spawning and nursery areas for many of the diadromous and
marine species that utilize the New York Bight. Important geological
features of the area include the Hudson Shelf Valley and Hudson Canyon,
which provide habitat for deep-sea coral that shelters benthic
invertebrates and fish. Nutrient-rich water created by water-column
stratification from spring through fall, known as the cold pool, plays
an essential role in the ecosystem and supports high biodiversity and
phytoplankton productivity. The average temperature of the cold pool
has increased due to changes to ocean circulation. The cold pool has
been decreasing over the last several decades with the smallest sizes
associated with warmer years while area fish distributions have shifted
north or offshore (Zoidis et al., 2021). The geology and geomorphology
in the New York Bight region are diverse with glacial deposits as a
result of the Pleistocene Epoch sea level falls and rises, and more
recent Flandrian transgression of sea level (Messina and Stoffer,
1996). Analysis of geophysical and geotechnical survey data collected
across the Lease Area indicates the current geological conditions
underlying the Lease Area are generally flat.
Water depths vary within the Lease Area from 24 m (78 ft) to 44 m
(144 ft), with deeper water depths in the southeast portion of the
Lease Area. From June to September, the average temperature of the
upper (10-15 m) water column is higher, which can lead to a surface
layer of increased sound speeds (Kusel et al. 2022). This creates a
downward refracting environment in which propagating sound interacts
with the seafloor more than in a well-mixed environment. Increased wind
mixing combined with a decrease in solar energy during winter, from
December through March, results in a sound speed profile that is more
uniform with depth.
Sediments in the project area are characterized as predominantly
sands and fine sands in the New York Bight area, which includes the
Lease Area and most of the submarine export cable routes, to
predominantly clays and silts in New York Bay, which includes a section
of the EW 1 submarine export cable route. Impact pile driving would
occur in a continental shelf environment characterized by predominantly
fine to coarse grained sandy seabed sediments, with some clay content.
The EW 1 submarine export cable route exits the Lease Area from the
northwestern edge of the Lease Area and will travel northwest through
Raritan Bay to the EW 1 export cable landfall in

[[Page 22700]]

Brooklyn, New York. Current geological conditions underlying the EW 1
submarine export cable route trend with shoaling towards the shore, and
with more significant variation in the bathymetry closer to shore,
where dredging patterns influence the seabed. Water depths vary along
the EW 1 submarine export cable route from 5.9 m (19.4 ft) to 31.7 m
(104.0 ft). Several channels exist along the submarine export cable
route, both natural and anthropogenic. The general gradient along the
cable is less than 1 degree, although isolated gradients of up to five
degrees exist along the near shore portion of the route.
The EW 2 submarine export cable route exits the Lease Area from the
central portion of the Lease Area and travels in a northwestern
direction in a relatively straight line until turning north to the EW 2
export cable landfall in Long Beach, New York. Conditions along the EW
2 submarine export cable route exhibit a general trend of shoaling
towards the shore. Water depth variations range, in the current
surveyed and interpreted portion of the route, from 21.5 m (70 ft) to
35.5 m (116 ft). The slope gradient along the EW 2 submarine export
cable route reaches a maximum of 1 degree.
Impact pile driving activities to install monopile and the piled
jacket foundations will occur within the proposed WTG and offshore
substation layout within EW 1 (Figure 3 in application). The WTGs and
offshore substations will be located in the Wind Farm Development Area
(WFDA), which is a subset of the Lease Area. EW 1 is located in the
northwest portion of the WFDA. Additionally, impact pile driving
activities to install monopile and the piled jacket foundations will
occur within the proposed WTG and offshore substation layout within EW
2 (Figure 3 in application). EW 2 is located in the southeast portion
of the WFDA.
Cable Landfall activities for EW 1 would occur at the South
Brooklyn Marine Terminal in Brooklyn, NY along the waterfront and
adjacent to 1st Avenue/2nd Avenue (Figure 1 in Application). The EW 1
submarine export siting corridor itself begins on the northern edge of
the EW 1 portion of the WFDA and extends northwest for approximately 40
nm (74 km). EW 2 landfall locations would occur at one of the following
locations: Landfall A (Riverside Boulevard); EW 2 Landfall B (Monroe
Boulevard); EW 2 Landfall C (Lido Beach West Town Park); or Landfall E
(Laurelton Boulevard). The final location is still being determined.
The EW 2 submarine export siting corridor itself begins on the
northwest corner of the EW 2 portion of the WFDA and extends northwest
for approximately 26 nm (48 km).
All marina activities, both the berthing pile removal and bulkhead
work, would be conducted at the Onshore Substation C location along
inshore Long Island on the Wreck Lead Channel. Wreck Lead Channel
adjoins Reynolds Channel. Reynolds Channel's median salinity is 30-32
practical salinity units (PSU) and dissolved oxygen levels range from
6-12 milligrams per decilitre (mg/dL), decreasing seasonally with
warming temperatures. The sediments in the New York Bight, outer
harbor, and barrier islands region are composed primarily of sand,
gravel, silt, and clay. Currents in the area are minimal and are
expected to be similar to those reported at Rockaway Inlet, which vary
between 0.0 and 1.0 knots.
BILLING CODE 3510-22-P

[[Page 22701]]

[GRAPHIC] [TIFF OMITTED] TP13AP23.110

BILLING CODE 3510-22-C

Detailed Description of Specific Activity

Below, we provide detailed descriptions of Empire Wind's
activities, explicitly noting those that are anticipated to result in
the take of marine mammals and for which incidental take authorization
is requested. Additionally, a brief explanation is provided for those
activities that are not expected to result in the take of marine
mammals.
WTG and OSS Foundation Installation
As described above, Empire Wind would construct two independent

[[Page 22702]]

projects under these proposed regulations: EW 1 and EW 2. In total, 147
WTGs would be installed. Turbine size includes either 9.6 or 11-m
diameter piles driven to a penetration depth of 38 m or 55 m
respectively. Both of the 9.6-m and 11-m piles would be installed using
a 5,500 kilojoule (kJ) impact pile driver, although only up to 5,225 kJ
would be necessary for the 9.6-m piles and up to 2,500 kJ would be used
for 11-m piles. Empire Wind anticipates installing up to 57 WTG
monopile foundations and 1 OSS jacket foundation for EW 1 and up to 90
WTG monopile foundations and 1 OSS jacket foundation for EW 2. Only one
foundation is proposed to be installed via pile driving at a given time
(i.e., no concurrent foundation-specific pile driving activities are
proposed) and there would be no overlap in pile driving activities
between EW 1 and EW 2. WTGs turbines would be installed in clearly
marked rows aligned with the dominant trawl directions when feasible.
Minimum spacing of no less than 0.65 nm (1.2 km) in a north-south
orientation will be maintained between WTGs. Additionally, the layout
maintains a 1 nm setback from existing shipping lanes.
Monopile installation techniques are as follows. Once the
installation vessel is in place, the steel pile is lifted into a
vertical position and lowered onto the seabed. The steel pile is then
driven into the seabed. Pile driving is conducted with the use of a
large crane mounted hydraulic impact hammer being dropped, or driven,
onto the top of a foundation pile, and driving it into the ground to a
penetration depth of up to 38 m for 9.6-m piles and 55 m for 11-m
piles. Each monopile pile will require a maximum of up to 3.5 hours of
impact pile driving. All monopiles would be installed using impact
hammers capable of reaching 5,500 kJ of energy. Typically, 9.6-m piles
would require a maximum energy level of 2,300 kJ; however, there may be
positions (up to 17) wherein the pile is difficult to drive due to
seabed conditions. These difficult-to-drive piles would require hammer
energies up to 5,225 kJ. Typically, 11-m piles require an energy level
of up to 2,500 kJ. An additional hammer energy schedule was generated
for difficult-to-drive monopiles (the difficult-to-drive hammer energy
schedule was generated only for the 9.6-m diameter scenario as larger
diameter monopiles could not be driven in difficult-to-drive
conditions).
Installation of each monopile will include a 20-minute soft-start
where lower hammer energy is used at the beginning of each pile
installation. Following pile driving, the transition piece and
secondary ancillary equipment are installed onto the steel pile. Only
one foundation is proposed to be installed via pile driving at a given
time and there will be no overlap in pile driving activities between EW
1 and EW 2.
Installation of the OSS foundations would be similar to WTG
foundation installation. Pin piles (2.5 m) for jacket foundations would
be installed via impact driving and would require the installation of
up to 12 pin piles per OSS. Once the installation vessel is in place,
the jacket structure is lifted from the vessel and lowered onto the
seabed. The support piles are placed in the jacket structure and then
driven into the seabed. The piles will be driven using the same
methodology as described for monopiles. Each pin pile will require a
maximum of up to 4.2 hours of impact pile driving. Pin piles at both
OSSs would require use of a hammer with an energy level of 4,000 kJ.
However, the maximum energy level would be 3,200 kJ at each location.
The OSS 1 location would have a penetration depth of 56 m while OSS 2
would have a penetration depth of 47 m. Installation of each pin pile
would include a 20-minute soft-start where lower hammer energy is used
at the beginning of each pile installation. Following pile driving of
the pin piles, the jacket structure is secured to the driven piles.
Seabed preparation will include installation of a filter layer
prior to monopile installation and an armor layer after cable
installation on each WTG location. The filter layer and armor layer are
rock layers installed on the seabed to prevent scour due to flow
increase around the monopiles. This activity would not have any impacts
on marine mammals.
Foundation installation is scheduled for May through November in
2025 and 2026. Pile driving in December would not occur unless
unforeseen circumstances arise. Foundation installation pile driving
would not occur January 1-April 30 of any year. Pile driving would
occur during daylight hours, only extending into night if Empire Wind
starts installing a pile 1.5 hours prior to civil sunset.
Installation of WTG monopile foundations and OSS pin piles are
anticipated to result in the take of marine mammals due to noise
generated during pile driving. Therefore, Empire Wind has requested,
and NMFS proposes to authorize, take (by Level A harassment and Level B
harassment) of marine mammals incidental to foundation installation.
Cable Landfall Construction
To connect the offshore export cable to the onshore cable, Empire
Wind proposes to conduct construction related activities at two cable
landfall sites. The export cable landfall for the EW 1 export cables
will occur at SBMT, located along the Brooklyn waterfront and adjacent
to 1st Avenue/2nd Avenue. The cable landfall site for EW2 has not yet
been chosen but will occur somewhere between Jones Beach to Long Beach,
NY. Installation of the export cable landfall will be accomplished
using a horizontal directional drilling (HDD) methodology. HDD
operations for an export cable landfall originate from an onshore
landfall location and exit a certain distance offshore, which is
determined by the water depth contour, as well as total length
considerations. To support this installation, both onshore and offshore
work areas are required. The onshore work areas are typically located
within the landfall parcels. Target transition depths of landfall HDD
paths vary by the length of the HDD, up to approximately 80 ft (24 m).
Once the onshore work area is set up, the HDD activities commence using
a rig that drills a borehole underneath the surface. Once the drill for
the HDDs exits onto the seafloor, the ducts in which the submarine
cable will be installed are floated out to sea and then pulled back
onshore within the drilled borehole. The offshore exit locations
require some seafloor preparation to collect any drilling fluids that
localize during HDD completion. Preparation will include excavation of
pits at each offshore exit location. To facilitate the retaining of
drilling fluids, Empire Wind may utilize a casing pipe supported by
goal posts on the exit side from a jack-up barge or cofferdams (but not
both). The jack-up barge will also house the drill rig.
If Empire Wind installs temporary cofferdams to facilitate
transition of the export cable to the onshore cable, up to five
cofferdams would be required (up to two cofferdams for EW 1 and three
cofferdams for EW 2). Each cofferdam would be installed using vibratory
driving over 3 days and removed over 3 days for a total of 6 days for
each cofferdam (or 30 days total (5 cofferdams x 6 days of pile driving
per cofferdam)). Empire Wind anticipates only 1 hour of pile driving
would be required each day (30 hours total). The temporary offshore
cofferdams will be constructed by installing up to 60 0.61-m (24-inch)
steel sheet piles per cofferdam in a tight configuration around an area
of up to 30 m by 30 m (100 ft by 100 ft). A total of up to five

[[Page 22703]]

temporary cofferdams may be constructed (two cofferdams for EW 1 and
three cofferdams for EW 2). Variation in the final cofferdam design is
possible, with designs ranging from 30 to 40 sheet piles per cofferdam.
To be conservative, up to 60 sheet piles per cofferdam have been
accounted for in the modeling (see Estimated Take of Marine Mammals
section). Sheet piles would be installed with a vibratory hammer.
Vibratory pile drivers install piling into the ground by applying a
rapidly alternating force to the pile. This is generally accomplished
by rotating eccentric weights about shafts. Each rotating eccentric
produces a force acting in a single plane and directed toward the
centerline of the shaft. The weights are set off-center of the axis of
rotation by the eccentric arm. If only one eccentric is used, in one
revolution a force will be exerted in all directions, giving the system
a good deal of lateral whip. To avoid this problem, the eccentrics are
paired so the lateral forces cancel each other, leaving only axial
force for the pile.
Seabed preparation may also be completed with installation of a
cofferdam for each HDD and an excavation pit to remove material from
the cofferdam. The pit would likely be excavated using a bucket--there
are no acoustic impacts from this activity if it were to occur and
therefore no potential for take.
An alternative to the use of cofferdams for the cable landfall
would be the use of a casing pipe supported by up to 3 goal posts. The
casing pipe at each landfall location would likely be a 42'' pipe
installed with a pneumatic hammer. Empire Wind estimates it would take
approximately 4 hours to install the casing pipe with a strike rate of
180 strikes/minute. Each goal post would consist of two piles for a
total of 18 piles at each landfall location. Each goal post pile would
be installed with an impact hammer requiring up to 2,000 strikes per
pile over 2 hours. In total, up to 36 hours (18 piles x 2 hours per
pile) of impact pile driving to install three goal posts may occur.
For the goal post installation process, a barge with necessary
support equipment is first mobilized and anchored into position. The
support equipment on the barge will include at least one crane, a
hydraulic impact hammer mounted at the end of the crane hook or load
block, and the piles to be driven. An additional crane or similar
equipment may also be located on the support barge to aid in the
handling of the goal post piles. For each HDD installation, it is
estimated that three goal posts will need to be installed to support
the casing pipe. Therefore, for each HDD installation there could be up
to ten 12-inch piles. For each goal post, a total of two 12-inch steel
piles must be driven to complete a single goal post installation, with
2,000 strikes per pile. The piles are installed by attaching the
hydraulic hammer to the end of the pile, and lifting the hydraulic
hammer with the crane, and swinging the pile into place for the goal
post installation. The hydraulic hammer then drives the pile into the
subsea floor by repeated percussive blows until the pile reaches a
sufficient depth where enough strength to support the casing pipe is
achieved. This process is repeated until all piles necessary for the
goal post are installed.
HRG Surveys
Empire Wind would conduct HRG surveys in the EW 1 and EW 2 marine
environment of the approximately 321 km\2\ (79,350 acres) Lease Area
and along the submarine export cable route corridors, inter-array cable
locations, and export cable landfall sites. The HRG survey activities
will include the following equipment summarized in Table 2, or
comparable sources. HRG site characterization surveys would occur
annually throughout the five years the rule and LOA would be effective.
Empire Wind would conduct HRG surveys within the lease area and the
export cable corridor, including the cable landfall sites. The
estimated distance of the daily vessel track line was determined using
the estimated average speed of the vessel and the 24-hour operational
period within each of the corresponding survey segments. Empire Wind
proposes to use up to three vessels to conduct the surveys. The
estimated daily vessel track for all vessels is approximately 177.792
km (110.475 mi) for 24-hour operations with a daily ensonified area of
17.8 km\2\. The number of active survey vessel days ranges from 41 (in
2024) to 191 (in 2025). There would be an anticipated 483 survey days
over the 5-year LOA period covering 85,872 km. The duration of each
survey varies as described in Table 11 in the application. The survey
schedule is based on 24-hour operations and includes estimated weather
down time.
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. Surveys would occur
annually, with durations dependent on the activities occurring in that
year (i.e., construction years versus operational years).
Of the HRG equipment types proposed for use, only Shallow
penetration sub-bottom profilers (SBPs) have the potential to result in
take. SBPs would be used 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. Boomers and
sparkers would not be used during HRG surveys.
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. Equipment
with operating frequencies above 180 kHz (e.g., SSS, MBES) 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. No harassment exposures can be reasonably expected
from the operation of these sources; therefore, they are not considered
further in this proposed action.

Table 2--Summary of Representative HRG Survey Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Operating Primary Pulse duration Pulse
Representative HRG equipment \a\ frequencies RMS source Peak source beamwidth (milliseconds repetition
(kHz) level level (degrees) (ms)) (Hz)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Kongsberg HiPAP 501/502 USBL............................ 21--31 190 207 Omni 2 0.5-2

[[Page 22704]]

iXblue, IxSea GAPS Beacon System........................ 8-16 188 194 Omni 10 1
Sonardyne Ranger 2 and Mini Ranger 2 USBL HPT 3000/5/ 19-34 200 206 Omni 5 1
7000...................................................
Reson Seabat T20P multibeam echosounder \a\............. 200-400 221 227 90 0.253 ..............
Reson 7111.............................................. 100 224 228 6 1.35 ..............
Kongsberg EM2040Quad.................................... 200-400 - - - - ..............
R2 Sonic 2026........................................... 170-450 191 221 1 1.115 ..............
R2 Sonic 2024........................................... 200-700 - - - - ..............
Klein 3900 SSS \a\...................................... 445-900 200 226 1.8 0.1 ..............
EdgeTech DW106.......................................... 1 to 6 194 197 Omni <66 8
EdgeTech 424 \a\........................................ 4-20 180 186 122 4.8 ..............
Innomar, SES-2000 compact............................... 85-115 232 238 4 40 1
Innomar, SES-2000 Light & Light Plus.................... 85-115 232 238 4 40 1
Innomar, SES-2000 Standard & Standard Plus.............. 85-115 234 240 1-3.5 60 1.5
Innomar, SES-2000 Smart................................. 90-110 229 235 5 40 0.5
Innomar, SES-2000 Medium-70............................. 60-80 240 246 3 40 5
Teledyne Benthos Chirp III-TTV 170...................... 2 to 7 219 225 100 60 15
Coda Octopus 3D......................................... 240-300 - - - - 20
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note:
\a\ Equipment specifications found in the 2016 Crocker and Fratantonio Report. Equipment selected would be the same or similar.
``-'' indicates Empire Wind was unable to provide this information; however, it is not relevant to the analysis herein.

Based on the operating frequencies of some types of HRG survey
equipment and the hearing ranges of the marine mammals that have the
potential to occur in the Project Area, HRG survey activities will have
the potential to result in Level B harassment of marine mammals. No
Level A harassment is anticipated as a result of HRG survey activities.
Onshore Substation C Marina Activities
Construction activities will also be completed to facilitate the
connection of the cables to Onshore Substation C, located inshore Long
Island on the Wreck Lead Channel, as shown in Figure 1. Work includes
removing berthing piles and bulkhead repair. Up to 130 12-inch diameter
timber berthing piles would be removed using a combination of a crane
and vibratory hammer, depending on the condition of the piles. Two
piles would be removed each hour with up to 15 piles per day (7-8 hours
per day) with approximately 130 piles removed over the course of two
weeks for a total of approximately 65 hours. Vibratory installation of
24-inch z-type steel sheet piles would also occur at the marina
bulkheads, consisting of 20 piles per day, with installation occurring
for approximately 1 hour of noise generation time per day for 35 days.
The onshore substation will be used to transform and prepare the
power received by the export cables from EW 2 for connection to the
points of interconnection (POIs) in New York. SMBT Vibratory
installation of sheet piles would also occur at the marina bulkheads,
consisting of 20 piles per day, with installation occurring for
approximately 1 hour of noise generation time per day for 35 days for a
total of 700 sheet piles between Q1-Q4 for EW 1 and EW 2 in 2024 and
between Q1-Q4 for EW 2 in 2025.
Barnums Channel Cable Bridge Activities
The cable bridge structure for EW 2 only requires two support
columns (pile caps) located within the waterway to support the truss
system, which will hold the cables above water. The support may be
installed by a hammer, but other methods are under consideration. There
could be up to six 1.5 ft (0.5 meter) diameter steel pipe piles per cap
for a total of 12 steel pipe piles. The location is in an inland
waterway near the Barrett Generation Station in an industrialized
section of the island, where water depths are only 1 meter, therefore,
marine mammals, including seals, are not expected. Sightings data
support this assumption, as no sightings of seals have been recorded in
the vicinity (OBIS 2023). No take is anticipated from this activity.

Cable Laying and Installation

Submarine export cables will be installed from specialized
installation vessels/barges, which will install the cables from a
turntable on the lay vessel/barge. One or several vessels might be used
for the installation of the cables depending on a number of factors,
such as seabed depth, depth of cable protection, distance to shore, and
cable protection method to be used. There are several cable
installation and burial methods being considered. Some activities will
be performed before the installation of the cables, some during the
installation of the cables, and some after the installation of the
cables. Cable pre-lay activities may include pre-installation grapnel
run, route clearance and boulder removal, pre-sweeping, dredging and
pre-trenching. The cable burial methods being considered are plowing,
jetting, trenching, and dredging. The equipment selected will depend on
seabed conditions, the required burial depths, as well as the results
of various cable burial studies. More than one installation and burial
method may be selected per route and has the potential to be used pre-
installation, during installation, and/or post-installation.
Installation of the submarine export cables is expected to take
approximately four months for the EW 1 submarine export cables and
approximately four months for the EW 2 submarine export cables. The
actual installation schedule will be subject to seabed characteristics,
installation vessel availability, seasonal restriction windows for
protected species, and weather. Installation of the EW 1 and EW 2
submarine export cables may occur at the same time; however,

[[Page 22705]]

any overlap in installation activities would not occur at the same
stage (i.e., pre-installation activities may commence for EW 2 while
the cable lay and burial for EW 1 is being completed).
The noise levels generated from cable laying and installation work
are low so the potential for take of marine mammals to result is
discountable. Empire 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.

Vessel Operation

Multiple vessels will be in use during construction and operations.
Empire Wind estimates that the Project will require approximately 18
vessels for construction of EW 1 and approximately 18 vessels for
construction of EW 2. Vessels including barges, tugboats, crew transfer
vessels, heavy transport vessels, and various supply vessels are
expected to be utilized. Helicopters may also be used to provide site
support (Table 3).

Table 3--Preliminary Summary of Offshore Vessels for Construction
--------------------------------------------------------------------------------------------------------------------------------------------------------
Foundations Offshore
----------------------------------------------------------------------------------- Substation
Topside &
Wind Foundation Submarine Interarray Scour
turbines -------------- Export Cables Protection
Vessel Description Monopile Piled Jacket Substation Cables
Topside &
Foundation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Heavy lift vessel................ Vessel for X X ............ X ............ ............ ............
installation of
foundations.
Monopile supply vessel........... Vessel for X ............ ............ ............ ............ ............ ............
transport of
monopile
foundations.
Wind turbine installation vessel. Vessel for ............ ............ X ............ ............ ............ ............
installation of
wind turbine
components.
Wind turbine supply vessel....... Vessel for ............ ............ X ............ ............ ............ ............
transport of wind
turbine components.
Cable lay vessel/barge........... Vessel for ............ ............ ............ ............ X X ............
installation of
submarine cables.
Heavy transport vessel........... Vessel for X X ............ X ............ ............ ............
transport of
offshore
substation topside.
Cable lay support vessel......... Support vessel for ............ ............ ............ ............ X X ............
cable lay
operations.
Pre-lay grapnel run vessel....... Vessel for seabed ............ ............ ............ ............ X X ............
clearance along
cable routes.
Fall pipe vessel................. Vessel for X X ............ X X X X
installation of
scour protection.
Crew transfer vessel............. Vessel for X X X X X X ............
transporting
workers to and
from shore.
----------------------------
Accommodation vessel............. Vessel for worker ............ ............ ............ X ............ ............
accommodations.
----------------------------
Construction support vessel...... Vessel for general X X ............ ............ X X ............
construction
support.
Tugboat.......................... Vessel for X X X X X ............ ............
transporting and
maneuvering barges.
Barge............................ Vessel for X X X X ............ ............ ............
transport of
construction
materials.
Safety vessel.................... Vessel for X X ............ ............ X X ............
protection of
construction areas.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Fisheries and Benthic Monitoring
Empire Wind will engage in various fisheries and benthic monitoring
surveys that 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). Empire Wind would conduct a number of
surveys including trawl surveys, baited underwater video surveys, and
hard bottom monitoring surveys.
Because the gear types and equipment used for 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. Only trawl surveys, in general, have the potential to result
in harassment to marine mammals. Empire Wind did not propose to
implement mitigation measures to avoid take of marine mammals
incidental to trawl surveys; however, NMFS has included them in this
proposed rule (see Proposed Mitigation). With the implementation of
those measures, NMFS does not anticipate, and is not proposing to
authorize, take associated with fisheries and benthic monitoring
surveys.

Description of Marine Mammals in the Area of Specified Activities

Thirty-eight marine mammal species under NMFS' jurisdiction have
geographic ranges within the western North Atlantic OCS (Hayes et al.,
2022). However, for reasons described below, Empire Wind has requested,
and NMFS proposes to authorize, take of 17 species (comprising 18
stocks) of marine mammals. Sections 3 and 4 of Empire Wind's
application summarize available information regarding status and
trends, distribution and habitat preferences, and behavior and life
history of the potentially affected species (Empire Wind, 2022). 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

[[Page 22706]]

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>).
Of the 38 marine mammal species in the Atlantic OCS under NMFS'
jurisdiction, 21 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
Empire Wind project area based on the best scientific information
available: blue whale (Balaenoptera musculus), 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), melon-headed whale (Peponocephala electra), white-beaked
dolphin (Lagenorhynchus albirotris), pantropical spotted dolphin
(Stenella attenuata), Clymene dolphin (Stenella clymene), striped
dolphin (Stenella coeruleoalba), spinner dolphin (Stenella
longirostris), Fraser's dolphin (Lagenodelphis hosei), and rough-
toothed dolphin (Steno bredanensis) and the hooded seal (Cystophora
cristata).
In addition, Florida manatees (Trichechus manatus; a sub-species of
the West Indian manatee) have been previously documented as an
occasional visitor to the Northeast region during summer months.
However, manatees are managed by the U.S. Fish and Wildlife Service and
are not considered further in this document.
In anticipation of the Empire Wind Project, Equinor (prior to
establishing its subsidiary, Empire Wind) conducted 12 monthly aerial
digital surveys of Empire Wind Lease Area OCS-A 0512 in the New York
Bight between November 2017 and October 2018 using APEM Inc.'s high-
resolution camera system to capture digital still imagery. Raw counts
and design-based abundance estimates of all species and incidental
observations recorded during the surveys are presented here as well as
information on species distribution, flight height and flight
direction. The key findings from each of the monthly aerial digital
surveys are summarized below. (Normandeau-APEM, 2019). Common dolphins
were the most abundant marine mammal species recorded, with a peak
count (n=68) in the May survey, followed by bottlenose dolphins, with a
peak raw count (n=22) in the June survey. Harbor porpoises, minke
whales and a single humpback whale were also recorded, as were three
unidentified dolphins and three unidentified marine mammals. Marine
mammals were recorded in peak numbers in spring. Equinor's required
marine mammal monitoring report as part of HRG surveys covering Lease
Area OCS-A 0512 and the associate export cable routes from September
20, 2020 through September 19, 2021 reported sightings of humpback
whales, bottlenose dolphins, common dolphins, unidentifiable dolphin
species, and harbor seals. Between April 19, 2019 through July 22,
2019, Equinor also observed fin whales, humpback whales, unidentified
whales, common bottlenose dolphins, unidentifiable dolphins, and gray
seals during HRG surveys. The lack of detections of any of the 22
species listed above during these surveys reinforces the fact that they
are not expected to occur in the project area. As these species are not
expected to occur in the project area during the proposed activities,
Equinor did not request, and NMFS does not propose to authorize, take
of these species, and they are not discussed further in this document.
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), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (16 U.S.C. 1362(20)), as
described 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 species, 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' final 2021 SARs (Hayes et al., 2022) and draft
2022 SARs 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>.

T able 4--Marine Mammal Species Likely To Occur Near the Project Area That May Be Taken by Empire 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 338 (0; 332; 2020) \ 0.7 8.1
5\.
Family Balaenopteridae (rorquals):
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
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 22707]]

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).
Migratory Coastal...... -, -, N 6,639 (0.41; 4,759; 48 12.2-21.5
2016).
Long-finned pilot whales........ Globicephala melas..... Western North Atlantic. -, -, N 39,215 (0.3; 30,627; 306 29
2016).
Short-finned pilot whales....... Globicephala Western North Atlantic. -, -, N 28,924 (0.24; 23,637; 236 136
macrorhynchus. 2016).
Risso's dolphin................. Grampus griseus........ Western North Atlantic. -, -, N 35,215 (0.19; 30,051; 301 34
2016).
Common dolphin (short-beaked)... Delphinus delphis...... Western North Atlantic. -, -, N 172,897 (0.21; 1,452 390
145,216; 2016).
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena 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; 1,458 4,453
2016).
Harbor seal..................... Phoca vitulina......... Western North Atlantic. -, -, N 61,336 (0.08; 57,637; 1,729 339
2018).
Harp seal \6\................... Pagophilus Western North Atlantic. -, -, N 7,600,000 (UNK, 426,000 178,573
grownlandicus. 7,100,000.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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\ 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> whale).
\6\ Harp seals are rare in the region; however, stranding data suggest this species may be present during activities that may take marine mammals.

As indicated above, all 17 species and 18 stocks in Table 4
temporally and spatially co-occur with the activity to the degree that
there is a potential for take. Four of the marine mammal species for
which take is requested are listed as threatened or endangered under
the ESA, including North Atlantic right, fin, sei, and sperm whales. In
addition to what is included in Sections 3 and 4 of Empire Wind's
application (<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-empire-offshore-wind-llc-construction-empire-wind-project-ew1?check_logged_in=1">https://www.fisheries.noaa.gov/action/incidental-take-authorization-empire-offshore-wind-llc-construction-empire-wind-project-ew1?check_logged_in=1</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 is no ESA-designated critical habitat 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 January 24, 2023, five UMEs in total are considered active, with
four of these occurring along the U.S. Atlantic coast for various
marine mammal species; of these, the most relevant to the Empire Wind
Project are the right whale, humpback whale, and northeast pinniped
UMEs, given the prevalence of these species in the project area. More
information on UMEs, including all active, closed, or pending, can be
found on NMFS' website at <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events">https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events</a>.
Below we include additional 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

[[Page 22708]]

a generic stock for management purposes. For humpback and sei whales,
NMFS defines stocks on the basis of feeding locations, i.e., Gulf of
Maine and Nova Scotia, respectively. However, references to humpback
whales and sei whales in this document refer to any individuals of the
species that are found in the specific geographic region. 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 was enacted in 1973. They were 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, 2017, and 2022 which concluded no change to the
listing status is warranted.
The North Atlantic right whale population had only a 2.8 percent
recovery rate between 1990 and 2011, and an overall abundance decline
of 29.7 percent from 2011-2020 (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 five 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.
The project area both spatially and temporally overlaps a portion
of the migratory corridor BIA within which 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).
In late fall (i.e., November), a portion of the right whale
population (including pregnant females) typically departs the feeding
grounds in the North Atlantic, moves south along the migratory corridor
BIA, including through the project area, to right whale calving grounds
off Georgia and Florida. However, recent research indicates
understanding of their movement patterns remains incomplete and not all
of the population undergoes a consistent annual migration (Davis et
al., 2017; Gowan et al., 2019; Krzystan et al., 2018). The results of
multistate temporary emigration capture-recapture modeling, based on
sighting data collected over the past 22 years, indicate that non-
calving females may remain in the feeding grounds, during the winter in
the years preceding and following the birth of a calf to increase their
energy stores (Gowen et al., 2019).
Right whales are anticipated to occur in the proposed survey area
year-round but with lower levels in the summer from July-September.
(Estabrook et al., 2021). Recent aerial surveys in the New York Bight
showed right whales near the proposed survey area with the highest
sighting rate in spring, followed by winter, preferring deeper waters
near the shelf break (right whales observed in depths ranging from 33-
1,041 m), but were observed throughout the survey area. No right whales
were observed in summer months (Normandeau Associates and APEM, 2020;
Zoidis et al., 2021). Similarly, passive acoustic data collected from
2018 to 2020 in the New York Bight showed detections of right whales
throughout the year. During the Year 3 survey period, North Atlantic
right whales were detected in each month, except in February, March,
and October 2020, with the most detections occurring in late fall
through early spring. Seasonally, North Atlantic right whale acoustic
presence was highest in the fall at sites that were closer to New York
Harbor and during spring months at sites farthest from the Harbor
(Zoidis et al., 2021).
North Atlantic right whales present in the Empire Wind project area
are primarily migrating through. Some opportunistic foraging may occur
although core foraging habitat is located north of the project area in
Southern New England, Gulf of Maine and Gulf of St. Lawrence. Right
whales feed primarily on the copepod Calanus finmarchicus, a species
whose availability and distribution has changed both spatially and
temporally over the last decade due to an oceanographic regime shift
that has been ultimately linked to climate change (Meyer-Gutbrod et
al., 2021; Record et al., 2019; Sorochan et al., 2019). This
distribution change in prey availability has led to shifts in 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).
Elevated right whale mortalities have occurred since June 7, 2017,
along the U.S. and Canadian coast, with the leading category for the
cause of death for this UME determined to be ``human interaction,''
specifically from entanglements or vessel strikes. As of February,
2023, there have been 36 confirmed mortalities and 22 seriously injured
free-swimming whales for a total of 58. The UME also considers animals
with sublethal injury or illness, also known as morbidity cases. There
have been 39 bringing the total number of whales in the UME to 97.
2021), likely contributing to smaller body sizes at maturation, making
them more susceptible to threats and reducing fecundity (Moore et al.,
2021; Reed et al., 2022; Stewart et al., 2022). More information about
the North Atlantic right whale UME is available online at: <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2023-north-atlantic-right-whale-unusual-mortality-event">https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2023-north-atlantic-right-whale-unusual-mortality-event</a>.
NMFS' regulations at 50 CFR part 224.105 designated nearshore
waters of the Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal
Management Areas (SMAs) for right whales in 2008. These specific SMAs
were developed to reduce the threat of collisions between ships and
right whales around their migratory route and calving grounds. The SMA
southeast of Ports of New York/New Jersey is currently active from
November 1 through April 30 of each year and may be used by right
whales for feeding. As noted above, NMFS is proposing changes to the
North Atlantic right whale speed rule (87 FR 46921; August 1, 2022). In
addition, Dynamic Management Areas (DMAs) are areas of temporary
protection established by NOAA Fisheries for particular marine mammal
species, in an effort to respond to movements of high-risk whale
species (such as right whale). These DMAs are determined by sighting
reports made through vessel traffic in the larger Northern Atlantic and
are communicated through marine communication systems and published on
their website. The Right Whale Sighting Advisory System, a statutory

[[Page 22709]]

requirement to reduce the risk of right whale collisions, is in place
for any DMA. As noted above, NMFS is proposing changes to the North
Atlantic right whale speed rule (87 FR 46921; August 1, 2022).

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). 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).
There are no fin whale BIAs in the immediate vicinity of the
project area although a small feeding BIA is located approximately 140
km to the northeast offshore of Montauk Point, from March to October
(Hain et al., 1992; LaBrecque et al., 2015).

Minke Whale

Minke whales are among the most widely distributed of all the
baleen whales. They occur in the North Atlantic and North Pacific, from
tropical to polar waters. Generally, they inhabit warmer waters during
winter and travel north to colder regions in summer, while some animals
migrate as far as the ice edge. There appears to be a strong seasonal
component to minke whale distribution in the survey areas, in which
spring to fall are times of relatively widespread and common occurrence
while during winter the species appears to be largely absent (Waring et
al., 2016). Recent aerial surveys in the New York Bight area found that
minke whales were observed throughout the survey area, with highest
numbers sighting in the spring months (Normandeau Associates and APEM).
Minke whales are primarily documented near the continental shelf
offshore of New Jersey (Schwartz, 1962; Mead, 1975; Potter, 1979;
Rowlett, 1980; Potter, 1984; Winn et al., 1985, DoN, 2005). Acoustic
recordings of minke whales have been detected north of the Lease survey
area within the New York Bight during the fall (August to December) and
winter (February to May) (Biedron et al., 2009). Minke whales are most
common off New Jersey in coastal waters in the spring and early summer
as they move north to feeding ground in New England and fall as they
migrate south (Geo-Marine, 2010). Geo-Marine (2010) observed four minke
whales near the survey area and surrounding waters during winter and
spring. A juvenile minke whale was sighted northwest of the Lease
survey area near the New York Harbor in April 2007 (Hamazaki, 2002).
Minke whale sightings off the coast of New Jersey were within water
depths of 36 ft to 79 ft (11 m to 24 m) and temperatures ranging from
5.4 to 11.5 [deg]C (47 [deg]F) (Geo-Marine, 2010).
There are no minke whale BIAs in or near the project area. The
closest is a feeding BIA identified in the southern and southwestern
section of the Gulf of Maine from March through November, annually
(LeBrecque et al., 2015). A migratory route for minke whales transiting
between northern feeding grounds and southern breeding areas may exist
to the east of the proposed project area, as minke whales may track
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. However, that UME is now nonactive with closure
pending. During the active phase of the UME, a total of 140 strandings
had been reported with 21 occurring in New York and 11 in New Jersey.
Previous minke whale UMEs occurred in 2003 and 2005 (NOAA Fisheries
2018c). 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 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>.

Humpback Whale

Humpback whales are a cosmopolitan species, found worldwide in all
oceans, but were listed as endangered under the Endangered Species
Conservation Act (ESCA) in June 1970. In 1973, the ESA replaced the
ESCA, and humpbacks continued to be listed as endangered.
On September 8, 2016, NMFS divided the once single species into 14
distinct population segments (DPS), removed the species-level listing,
and, in its place, listed four DPSs as endangered and one DPS as
threatened (81 FR 62259; September 8, 2016). The remaining nine DPSs
were 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).
The project area does not overlap any designated critical habitat,
nor any identified BIAs or other known 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.
Four decades ago, humpback whales were infrequently sighted off the
US mid-Atlantic states (USMA, New York, New Jersey, Delaware, Maryland,
Virginia and North Carolina, CeTAP, 1982), but they are now regular
visitors. Humpback whales are now frequently seen inside the New York-
New Jersey harbor estuary and in the greater New York Bight (Brown et
al., 2018, 2019; King et al., 2021; Zoidis et al., 2021; Smith et al.,
2022). Based on a 2012-2018 dataset, mean occurrence was low (2.5
days), mean occupancy was 37.6 days, and 31.3 percent of whales
returned from one year to the next (Brown et al., 2022). Sightings of
mother-calf pairs are rare in the New York Bight Area, suggesting that
maternally directed fidelity may not be responsible for the presence of
young whales in this area (Brown et al., 2022).
Humpback whales belonging to the West Indies DPS typically feed in
the waters between the Gulf of Maine and Newfoundland during spring,
summer, and fall, but they have been observed feeding in other areas,
such as off the coast of New York and New Jersey, including in close-
proximity to the entrance of the Port of New York and New Jersey
(Sieswerda et al., 2015, Brown et al., 2019).
Recent aerial surveys in the New York Bight observed humpback
whales in the spring and winter, but sightings were reported year round
in the area (Normandeau Associates and APEM, 2020). During 36 line-
transect aerial surveys conducted systematically nearshore out to 120
nm from March 2017 to February 2020. Humpback whales preferred deeper
waters near the shelf break, but were observed throughout the area.
Additionally,

[[Page 22710]]

passive acoustic data recorded humpback whales in the New York Bight
throughout the year, but the presence was highest in the fall and
summer months (Estabrook et al., 2021). In addition, recent research
has demonstrated a higher occurrence and foraging use of the New York
Bight area by humpback whales than previously known.
Since January 2016, elevated humpback whale mortalities along the
Atlantic coast from Maine to Florida led to the declaration of a UME. A
total of 27 and 36 strandings have been reported in the waters off New
Jersey and New York, respectively. Partial or full necropsy
examinations have been conducted on approximately half of the 189 known
cases (as of February 2023). 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>.
Since December 1, 2022, the number of humpback strandings along the
mid-Atlantic coast, including New York, has been elevated. In some
cases, the cause of death is not yet known. In others, vessel strike
has been deemed the cause of death. As the humpback whale population
has grown, they are seen more often in the Mid-Atlantic. Along the New
York/New Jersey shore, these whales may be following their prey which
are reportedly close to shore this winter. These prey also attract fish
that are of interest to recreational and commercial fishermen. This
increases the number of boats in these areas. More whales in the water
in areas traveled by boats of all sizes increases the risk of vessel
strikes. Vessel strikes and entanglement in fishing gear are the
greatest human threats to large whales.

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
Empire 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>.
There are several seal haul-out sites in New York. Harbor seals
generally predominate in the onshore haul-out sites but gray seals
intermix and are present as well. There are 26 known haul-out sites on
Long Island, New York (CRESLI, 2019). During surveys from 2004-2019, a
total of 18,321 harbor seals were documented using these sites (CRESLI,
2019). While there are no known haul-out sites directly at or near the
proposed nearshore activities (i.e., cable landfall construction,
marine activities), harbor seals will occur throughout the New York
coastline and have potential to haul out at many beach sites. The only
known and consistently used gray seal haul out locations are along the
sandy shoals located closer to Monomoy Refuge and on Nantucket, both in
Massachusetts (Kenney and Vigness-Raposa 2010). This species has been
reported with greater frequency in waters south of Cape Cod in recent
years, likely due to a population rebound in the Mid-Atlantic (Kenney
and Vigness-Raposa 2010).

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]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).

[[Page 22711]]

High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).

The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Seventeen marine mammal species (14 cetacean species (6 mysticetes and
8 odontocetes) and 3 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.

Acoustic Habitat

Acoustic habitat is defined as distinguishable soundscapes
inhabited by individual animals or assemblages of species, inclusive of
both the sounds they create and those they hear (NOAA, 2016). All of
the sound present in a particular location and time, considered as a
whole, comprises a ``soundscape'' (Pijanowski et al., 2011). When
examined from the perspective of the animals experiencing it, a
soundscape may also be referred to as ``acoustic habitat'' (Clark et
al., 2009, Moore et al., 2012, Merchant et al., 2015). High value
acoustic habitats, which vary spectrally, spatially, and temporally,
support critical life functions (feeding, breeding, and survival) of
their inhabitants. Thus, it is important to consider acute (e.g.,
stress or missed feeding/breeding opportunities) and chronic effects
(e.g., masking) of noise on important acoustic habitats. Effects that
accumulate over long periods can ultimately result in detrimental
impacts on the individual, stability of a population, or ecosystems
that they inhabit.

Potential Effects 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 section, to draw conclusions regarding the
likely impacts of these activities on the reproductive success or
survivorship of individuals and how those impacts on individuals are
likely to impact marine mammal species or stocks. General background
information on marine mammal hearing was provided previously (see the
Description of Marine Mammals in the Area of the Specified Activities
section). Here, the potential effects of sound on marine mammals are
discussed.
Empire Wind has requested, and NMFS proposes to authorize, the
taking of marine mammals incidental to construction activities
associated with in the EW 1 and EW 2 project area. In their
application, Empire Wind presented analyses of potential impacts to
marine mammals from use of acoustic sources. NMFS both carefully
reviewed the information provided by Empire Wind, as well as
independently reviewed applicable scientific research and literature
and other information to evaluate the potential effects of Empire
Wind's activities on marine mammals.
The proposed activities would result in placement of up to 147
permanent monopiles foundations and two OSS jacket foundations in the
marine environment. There are a variety of the types and degrees of
effects to marine mammals, prey species, and habitat that could occur
as a result from the project. Below we provide a brief description of
the types of sound sources that would be generated by the project, the
general impacts from these types of activities, and an analysis of the
anticipated impacts on marine mammals from the project, with
consideration of the proposed mitigation measures.

Description of Sound Sources

This section contains a brief technical background on sound, on the
characteristics of certain sound types, and on metrics used in this
proposal inasmuch as the information is relevant to the specified
activity and to a discussion of the potential effects of the specified
activity on marine mammals found later in this document. For general
information on sound and its interaction with the marine environment,
please see, 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
1500 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

[[Page 22712]]

characteristics of the transmission medium, such as water temperature
and salinity. Sound travels in water more efficiently than almost any
other form of energy, making the use of acoustics ideal for the aquatic
environment and its inhabitants. In seawater, sound travels at roughly
1500 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
ten times louder. Decibels are a relative unit comparing two pressures,
therefore a reference pressure must always be indicated. For underwater
sound, this is 1 microPascal ([mu]Pa). For in-air sound, the reference
pressure is 20 microPascal ([mu]Pa). The amplitude of a sound can be
presented in various ways; however, NMFS typically considers three
metrics. In this proposed rule, all decibel levels referenced to
1[mu]Pa.
Sound exposure level (SEL) represents the total energy in a stated
frequency band over a stated time interval or event, and considers both
amplitude and duration of exposure (represented as dB re 1 [mu]Pa\2\-
s). SEL is a cumulative metric; it can be accumulated over a single
pulse (for pile driving this is often referred to as single-strike SEL;
SEL<INF>ss</INF>), or calculated over periods containing multiple
pulses (SEL<INF>cum</INF>). Cumulative SEL represents the total energy
accumulated by a receiver over a defined time window or during an
event. The SEL metric is useful because it allows sound exposures of
different durations to be related to one another in terms of total
acoustic energy. The duration of a sound event and the number of
pulses, however, should be specified as there is no accepted standard
duration over which the summation of energy is measured.
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Root mean square is calculated by squaring
all of the sound amplitudes, averaging the squares, and then taking the
square root of the average (Urick, 1983). Root mean square accounts for
both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper, 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units than by peak pressures.
Peak sound pressure (also referred to as zero-to-peak sound
pressure or 0-pk) is the maximum instantaneous sound pressure
measurable in the water at a specified distance from the source, and is
represented in the same units as the rms sound pressure. Along with
SEL, this metric is used in evaluating the potential for PTS (permanent
threshold shift) and TTS (temporary threshold shift).
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, 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 one second), broadband,
atonal transients (ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO,
2003) and occur either as isolated events or repeated in some
succession. 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, and sonar. 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.

[[Page 22713]]

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. Human-generated sound is a significant contributor to the
acoustic environment in the project location.

Potential Effects of Underwater Sound on Marine Mammals

Anthropogenic sounds cover a broad range of frequencies and sound
levels and can have a range of highly variable impacts on marine life,
from none or minor to potentially severe responses, depending on
received levels, duration of exposure, behavioral context, and various
other factors. Broadly, underwater sound from active acoustic sources
such as those in the Empire Wind Project can potentially result in one
or more of the following: temporary or permanent hearing impairment,
non-auditory physical or physiological effects (e.g., stress),
behavioral disturbance, and masking (Richardson et al., 1995; Gordon et
al., 2003; Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et
al., 2009). Non-auditory physiological effects or injuries that
theoretically might occur in marine mammals exposed to high level
underwater sound or as a secondary effect of extreme behavioral
reactions (e.g., change in dive profile as a result of an avoidance
reaction) caused by exposure to sound include neurological effects,
bubble formation, resonance effects, and other types of organ or tissue
damage (Cox et al., 2006; Southall et al., 2007; Zimmer and Tyack,
2007; Tal et al., 2015).
In general, the degree of effect of an acoustic exposure is
intrinsically related to the signal characteristics, received level,
distance from the source, and duration of the sound exposure, in
addition to the contextual factors of the receiver (e.g., behavioral
state at time of exposure, age class, etc). In general, sudden, high
level sounds can cause hearing loss as can longer exposures to lower
level sounds. Moreover, any temporary or permanent loss of hearing will
occur almost exclusively for noise within an animal's hearing range. We
describe below the specific manifestations of acoustic effects that may
occur based on the activities proposed by Empire Wind.
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur, in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First (at the greatest distance) is the area within which the
acoustic signal would be audible (potentially perceived) to the animal
but not strong enough to elicit any overt behavioral or physiological
response. The next zone (closer to the receiving animal) corresponds
with the area where the signal is audible to the animal and of
sufficient intensity to elicit behavioral or physiological
responsiveness. The third is a zone within which, for signals of high
intensity, the received level is sufficient to potentially cause
discomfort or tissue damage to auditory or other systems. Overlaying
these zones to a certain extent is the area within which masking (i.e.,
when a sound interferes with or masks the ability of an animal to
detect a signal of interest that is above the absolute hearing
threshold) may occur; the masking zone may be highly variable in size.
Below, we provide additional detail regarding potential impacts on
marine mammals and their habitat from noise in general, as well as from
the specific activities Empire 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 or cetaceans).
Hearing Threshold Shift
Marine mammals exposed to high-intensity sound, or to lower-
intensity sound for prolonged periods, can experience hearing threshold
shift (TS), which NMFS defines as a change, usually an increase, in the
threshold of audibility at a specified frequency or portion of an
individual's hearing range above a previously established reference
level, expressed in decibels (NMFS, 2018). Threshold shifts can be
permanent (permanent threshold shift; PTS), 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
(temporary threshold shift; TTS), 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, but 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

[[Page 22714]]

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.
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., 2016 a,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).
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.
Behavioral Effects
Exposure of marine mammals to sound sources can result in, but is
not limited to, no response or any of the following observable
responses: Increased alertness; orientation or attraction to a sound
source; vocal modifications; cessation of feeding; cessation of social
interaction; alteration of movement or diving behavior; habitat
abandonment (temporary or permanent); and, in severe cases, panic,
flight, stampede, or stranding, potentially resulting in death
(Southall et al., 2007). A review of marine mammal responses to
anthropogenic sound was first conducted by Richardson (1995). More
recent reviews (Nowacek et al., 2007; DeRuiter et al., 2012 and 2013;
Ellison et al., 2012; Gomez et al., 2016; Southall et al., 2021))
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
not only on the species receiving the sound and the sound source, but
also on 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

[[Page 22715]]

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 (in this case, distance) may moderate reactions. Thus, distance
from the source is an important variable in influencing the type and
degree of behavioral response and this is 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 exists to
potentially quantitatively inform a take estimate. Other factors are
often considered qualitatively in the analysis of the likely
consequences of sound exposure, where supporting information is
available.
Friedlaender et al. (2016) provided the first integration of direct
measures of prey distribution and density variables incorporated into
across-individual analyses of behavior responses of blue whales to
sonar, and demonstrated a five-fold increase in the ability to quantify
variability in blue whale diving behavior. These results illustrate
that responses evaluated without such measurements for foraging animals
may be misleading, which again illustrates the context-dependent nature
of the probability of response.
The following subsections provide examples of behavioral responses
that give an idea of the variability in behavioral responses that would
be expected given the differential sensitivities of marine mammal
species to sound, contextual factors, and the wide range of potential
acoustic sources to which a marine mammal may be exposed. Behavioral
responses that could occur for a given sound exposure should be
determined from the literature that is available for each species, or
extrapolated from closely related species when no information exists,
along with contextual factors.
Avoidance and Displacement
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
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 previously noted in the literature, with
some significant variation in the temporal and spatial degree of
avoidance effects, 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

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(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 on impact driving at Horns Rev II in the North Sea near
Denmark, 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 of 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). For example, although there was no significant displacement
during construction as a whole, Russell et al. (2016) found that
displacement did occur during active pile driving at predicted received
levels between 168 and 178 dB re 1[micro]Pa<INF>(p-p)</INF>; however
seal distribution returned to the pre-piling condition within two hours
of cessation of pile driving. 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 two
years after construction began (Gilles et al. 2009). Approximately ten
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 pile
driving much smaller piles than Empire Wind proposes to install and
therefore we anticipate noise levels from impact pile driving to be
louder. For this reason, we anticipate that the greater distances of
displacement observed in harbor porpoise and harbor seals documented in
Europe are likely to occur off of New York. However, we do not
anticipate any greater severity of response due to harbor porpoise and
harbor seal habitat use off of New York or population level
consequences, similar to European findings. In many cases, harbor
porpoises and harbor seals are resident to the areas where European
wind farms have been constructed. However, off of 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.
Some avoidance behavior of other marine mammal species has been
documented to be dependent on distance from the source. As described
above, DeRuiter et al. (2013) noted that distance from a sound source
may moderate marine mammal reactions in their study of Cuvier's beaked
whales (an acoustically sensitive species), which showed the whales
swimming rapidly and silently away when a sonar signal was 3.4-9.5 km
away while showing no such reaction to the same signal when the signal
was 118 km away even though the received levels were similar. Tyack et
al. (1983) conducted playback studies of SURTASS low frequency active
(LFA) sonar in a gray whale migratory corridor off California. Similar
to North Atlantic right whales, gray whales migrate close to shore
(approximately +2 kms) and are low frequency hearing specialists. The
LFA sonar source was placed within the gray whale migratory corridor
(approximately 2 km offshore) and offshore of most, but not all,
migrating whales (approximately 4 km offshore). These locations
influenced received levels and distance to the source. For the inshore
playbacks, not unexpectedly, the louder the source level of the
playback (i.e., the louder the received level), whale avoided the
source at greater distances. Specifically, when the source level was
170 dB rms and 178 dB rms, whales avoided the inshore source at ranges
of several hundred meters, similar to avoidance responses reported by
Malme et al. (1983, 1984). Whales exposed to source levels of 185 dB
rms demonstrated avoidance levels at ranges of +1 km. Responses to the
offshore source broadcasting at source levels of 185 and 200 dB,
avoidance responses were greatly reduced. While there was observed
deflection from course, in no case did a whale abandon its migratory
behavior.
The signal context of the noise exposure has been shown to play an
important role in avoidance responses. In a 2007-2008 Bahamas study,
playback sounds of a potential predator--a killer whale--resulted in a
similar but more pronounced reaction in beaked whales (an acoustically
sensitive species), which included longer inter-dive intervals and a
sustained straight-line departure of more than 20 km from the area
(Boyd et al., 2008; Southall et al., 2009; Tyack et al., 2011). Empire
Wind does not anticipate, and NMFS is not proposing to authorize take
of beaked whales and, moreover, the sounds produced by Empire Wind do
not have signal characteristics similar to predators. Therefore we
would not expect such extreme reactions to occur. Southall et al. 2011
found that blue whales had a different response to sonar exposure
depending on behavioral state, more pronounced when deep feeding/travel
modes than when engaged in surface feeding.
One potential consequence of behavioral avoidance is the altered
energetic expenditure of marine mammals because energy is required to
move and avoid surface vessels or the sound field associated with
active sonar (Frid and Dill, 2002). Most animals can avoid that
energetic cost by swimming away at slow speeds or speeds that minimize
the cost of transport (Miksis-Olds, 2006), as has been demonstrated in
Florida manatees (Miksis-Olds, 2006). 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

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species may be critical to avoiding population-level impacts because
(particularly for animals with high site fidelity) there may be a
strong motivation to remain in the area despite negative impacts.
Forney et al. (2017) stated that, for these animals, remaining in a
disturbed area may reflect a lack of alternatives rather than a lack of
effects.
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996; Frid and Dill, 2002). The result of a flight response
could range from brief, temporary exertion and displacement from the
area where the signal provokes flight to, in extreme cases, beaked
whale strandings (Cox et al., 2006; D'Amico et al., 2009). However, it
should be noted that response to a perceived predator does not
necessarily invoke flight (Ford and Reeves, 2008), and whether
individuals are solitary or in groups may influence the response.
Flight responses of marine mammals have been documented in response to
mobile high intensity active sonar (e.g., Tyack et al., 2011; DeRuiter
et al., 2013; Wensveen et al., 2019), and more severe responses have
been documented when sources are moving towards an animal or when they
are surprised by unpredictable exposures (Watkins 1986; Falcone et al.,
2017). Generally speaking, however, marine mammals would be expected to
be less likely to respond with a flight response to either stationery
pile driving (which they can sense is stationery and predictable) or
significantly lower-level HRG surveys, unless they are within the area
ensonified above behavioral harassment thresholds at the moment the
source is turned on (Watkins, 1986; Falcone et al., 2017).
Diving and Foraging
Changes in dive behavior in response to noise exposure can vary
widely. They may consist of increased or decreased dive times and
surface intervals as well as changes in the rates of ascent and descent
during a dive (e.g., Frankel and Clark, 2000; Costa et al., 2003; Ng
and Leung, 2003; Nowacek et al.; 2004; Goldbogen et al., 2013a, 2013b).
Variations in dive behavior may reflect interruptions in biologically
significant activities (e.g., foraging) or they may be of little
biological significance. Variations in dive behavior may also expose an
animal to potentially harmful conditions (e.g., increasing the chance
of ship-strike) or may serve as an avoidance response that enhances
survivorship. The impact of a variation in diving resulting from an
acoustic exposure depends on what the animal is doing at the time of
the exposure, the type and magnitude of the response, and the context
within which the response occurs (e.g., the surrounding environmental
and anthropogenic circumstances).
Nowacek et al. (2004) reported disruptions of dive behaviors in
foraging North Atlantic right whales when exposed to an alerting
stimulus, an action, they noted, that could lead to an increased
likelihood of ship strike. The alerting stimulus was in the form of an
18 minute exposure that included three 2-minute signals played three
times sequentially. This stimulus was designed with the purpose of
providing signals distinct to background noise that serve as
localization cues. However, the whales did not respond to playbacks of
either right whale social sounds or vessel noise, highlighting the
importance of the sound characteristics in producing a behavioral
reaction. Although source levels for the proposed pile driving
activities may exceed the received level of the alerting stimulus
described by Nowacek et al. (2004), proposed mitigation strategies
(further described in the Proposed Mitigation section) will reduce the
severity of response to proposed pile driving activities. Converse to
the behavior of North Atlantic right whales, Indo-Pacific humpback
dolphins have been observed to dive for longer periods of time in areas
where vessels were present and/or approaching (Ng and Leung, 2003). In
both of these studies, the influence of the sound exposure cannot be
decoupled from the physical presence of a surface vessel, thus
complicating interpretations of the relative contribution of each
stimulus to the response. Indeed, the presence of surface vessels,
their approach, and speed of approach, seemed to be significant factors
in the response of the Indo-Pacific humpback dolphins (Ng and Leung,
2003). Low frequency signals of the Acoustic Thermometry of Ocean
Climate (ATOC) sound source were not found to affect dive times of
humpback whales in Hawaiian waters (Frankel and Clark, 2000) or to
overtly affect elephant seal dives (Costa et al., 2003). They did,
however, produce subtle effects that varied in direction and degree
among the individual seals, illustrating the equivocal nature of
behavioral effects and consequent difficulty in defining and predicting
them.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the cessation of secondary
indicators of foraging (e.g., bubble nets or sediment plumes), or
changes in dive behavior. As for other types of behavioral response,
the frequency, duration, and temporal pattern of signal presentation,
as well as differences in species sensitivity, are likely contributing
factors to differences in response in any given circumstance (e.g.,
Croll et al., 2001; Nowacek et al.; 2004; Madsen et al., 2006a;
Yazvenko et al., 2007; Southall et al., 2019b). An understanding of the
energetic requirements of the affected individuals and the relationship
between prey availability, foraging effort and success, and the life
history stage of the animal can facilitate the assessment of whether
foraging disruptions are likely to incur fitness consequences
(Goldbogen et al., 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

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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. Though the area ensonified by the HRG
sources is significantly smaller than from construction, the source
levels of both the proposed construction and HRG activities exceed the
source levels of the signals described by Nowacek et al., (2004) and
Croll et al., (2001), and noise generated by Empire Wind's activities
at least partially overlap in frequency with the described signals.
Blue whales exposed to mid-frequency sonar in the Southern California
Bight were less likely to produce low frequency calls usually
associated with feeding behavior (Melc[oacute]n et al., 2012). However,
Melc[oacute]n et al. (2012) were unable to determine if suppression of
low frequency calls reflected a change in their feeding performance or
abandonment of foraging behavior and indicated that implications of the
documented responses are unknown. Further, it is not known whether the
lower rates of calling actually indicated a reduction in feeding
behavior or social contact since the study used data from remotely
deployed, passive acoustic monitoring buoys. Results from the 2010-2011
field season of a behavioral response study in Southern California
waters indicated that, in some cases and at low received levels, tagged
blue whales responded to mid-frequency sonar but that those responses
were mild and there was a quick return to their baseline activity
(Southall et al., 2011; Southall et al., 2012b, Southall et al.,
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 [mu]Pa, but deep feeding and non-feeding
whales showed temporary reactions including cessation of feeding,
reduced initiation of deep foraging dives, generalized avoidance
responses, and changes to dive behavior (DeRuiter et al., 2017;
Goldbogen et al., 2013b; Sivle et al., 2015). Goldbogen et al. (2013b)
indicate that disruption of feeding and displacement could impact
individual fitness and health. However, for this to be true, we would
have to assume that an individual whale could not compensate for this
lost feeding opportunity by either immediately feeding at another
location, by feeding shortly after cessation of acoustic exposure, or
by feeding at a later time. There is no indication that individual
fitness and health would be impacted, particularly since unconsumed
prey would likely still be available in the environment in most cases
following the cessation of acoustic exposure.
Similarly, while the rates of foraging lunges decrease in humpback
whales due to sonar exposure, there was variability in the response
across individuals, with one animal ceasing to forage completely and
another animal starting to forage during the exposure (Sivle et al.,
2016). In addition, almost half of the animals that demonstrated
avoidance were foraging before the exposure but the others were not;
the animals that avoided while not feeding responded at a slightly
lower received level and greater distance than those that were feeding
(Wensveen et al., 2017). These findings indicate the behavioral state
of the animal and foraging strategies play a role in the type and
severity of a behavioral response. For example, when the prey field was
mapped and used as a covariate in examining how behavioral state of
blue whales is influenced by mid-frequency sound, the response in blue
whale deep-feeding behavior was even more apparent, reinforcing the
need for contextual variables to be included when assessing behavioral
responses (Friedlaender et al., 2016).
Vocalizations and Auditory Masking
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, production of echolocation clicks, calling,
and singing. Changes in vocalization behavior in response to
anthropogenic noise can occur for any of these modes and may result
directly from increased vigilance (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 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 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.
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 and to an animal's hearing
abilities (e.g., sensitivity, frequency range, critical ratios,
frequency discrimination, directional discrimination, age, or TTS
hearing loss), and existing ambient noise and propagation conditions.
Masking these acoustic signals can disturb the behavior of individual
animals, groups of animals, or entire populations. Masking can lead to
behavioral changes including vocal changes (e.g., Lombard

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effect, increasing amplitude, or changing frequency), cessation of
foraging or lost foraging opportunities, and leaving an area, to both
signalers and receivers, in an attempt to compensate for noise levels
(Erbe et al., 2016) or because sounds that would typically have
triggered a behavior were not detected. In humans, significant masking
of tonal signals occurs as a result of exposure to noise in a narrow
band of similar frequencies. As the sound level increases, though, the
detection of frequencies above those of the masking stimulus decreases
also. This principle is expected to apply to marine mammals as well
because of common biomechanical cochlear properties across taxa.
Therefore, when the coincident (masking) sound is man-made, it may
be considered harassment when disrupting behavioral patterns. It is
important to distinguish TTS and PTS, which persist after the sound
exposure, from masking, which only occurs during the sound exposure.
Because masking (without resulting in threshold shift) is not
associated with abnormal physiological function, it is not considered a
physiological effect, but rather a potential behavioral effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009; Matthews et al., 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).
The echolocation calls of toothed whales are subject to masking by
high-frequency sound. Human data indicate low-frequency sound can mask
high-frequency sounds (i.e., upward masking). Studies on captive
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species
may use various processes to reduce masking effects (e.g., adjustments
in echolocation call intensity or frequency as a function of background
noise conditions). There is also evidence that the directional hearing
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A
study by Nachtigall and Supin (2008) showed that false killer whales
adjust their hearing to compensate for ambient sounds and the intensity
of returning echolocation signals.
Impacts on signal detection, measured by masked detection
thresholds, are not the only important factors to address when
considering the potential effects of masking. As marine mammals use
sound to recognize conspecifics, prey, predators, or other biologically
significant sources (Branstetter et al., 2016), it is also important to
understand the impacts of masked recognition thresholds (often called
``informational masking''). Branstetter et al. (2016) measured masked
recognition thresholds for whistle-like sounds of bottlenose dolphins
and observed that they are approximately 4 dB above detection
thresholds (energetic masking) for the same signals. Reduced ability to
recognize a conspecific call or the acoustic signature of a predator
could have severe negative impacts. Branstetter et al. (2016) observed
that if ``quality communication'' is set at 90 percent recognition the
output of communication space models (which are based on 50 percent
detection) would likely result in a significant decrease in
communication range.
As marine mammals use sound to recognize predators (Allen et al.,
2014; Cummings and Thompson, 1971; Cur[eacute] et al., 2015; Fish and
Vania, 1971), the presence of masking noise may also prevent marine
mammals from responding to acoustic cues produced by their predators,
particularly if it occurs in the same frequency band. For example,
harbor seals that reside in the coastal waters off British Columbia are
frequently targeted by mammal-eating killer whales. The seals
acoustically discriminate between the calls of mammal-eating and fish-
eating killer whales (Deecke et al., 2002), a capability that should
increase survivorship while reducing the energy required to attend to
all killer whale calls. Similarly, sperm whales (Cur[eacute] et al.,
2016; Isojunno et al., 2016), long-finned pilot whales (Visser et al.,
2016), and humpback whales (Cur[eacute] et al., 2015) changed their
behavior in response to killer whale vocalization playbacks; these
findings indicate that some recognition of predator cues could be
missed if the killer whale vocalizations were masked. The potential
effects of masked predator acoustic cues depends on the duration of the
masking noise and the likelihood of a marine mammal encountering a
predator during the time that detection and recognition of predator
cues are impeded.
Redundancy and context can also facilitate detection of weak
signals. These phenomena may help marine mammals detect weak sounds in
the presence of natural or manmade noise. Most masking studies in
marine mammals present the test signal and the masking noise from the
same direction. The dominant background noise may be highly directional
if it comes from a particular anthropogenic source such as a ship or
industrial site. Directional hearing may significantly reduce the
masking effects of these sounds by improving the effective signal-to-
noise ratio.
Masking affects both senders and receivers of acoustic signals and,
at higher levels and longer duration, can potentially have long-term
chronic effects on marine mammals at the population level as well as at
the individual level. Low-frequency ambient sound levels have increased
by as much as 20 dB (more than three times in terms of SPL) in the
world's ocean from pre-industrial periods, with most of the increase
from distant commercial shipping (Hildebrand, 2009; Cholewiak et al.,
2018). All anthropogenic sound sources, but especially chronic and
lower-frequency signals (e.g., from commercial vessel traffic),
contribute to elevated ambient sound levels, thus intensifying masking.
In addition to making it more difficult for animals to perceive and
recognize acoustic cues in their environment, anthropogenic sound
presents separate challenges for animals that are vocalizing. When they
vocalize, animals are aware of environmental conditions that affect the
``active space'' (or communication space) of their vocalizations, which
is the maximum area within which their vocalizations can be detected
before it drops to the level of ambient noise (Brenowitz, 2004; Brumm
et al., 2004; Lohr et al., 2003).

[[Page 22720]]

Animals are also aware of environmental conditions that affect whether
listeners can discriminate and recognize their vocalizations from other
sounds, which is more important than simply detecting that a
vocalization is occurring (Brenowitz, 1982; Brumm et al., 2004;
Dooling, 2004; Marten and Marler, 1977; Patricelli et al., 2006). Most
species that vocalize have evolved with an ability to make adjustments
to their vocalizations to increase the signal-to-noise ratio, active
space, and recognizability/distinguishability of their vocalizations in
the face of temporary changes in background noise (Brumm et al., 2004;
Patricelli et al., 2006). Vocalizing animals can make adjustments to
vocalization characteristics such as the frequency structure,
amplitude, temporal structure, and temporal delivery (repetition rate),
or ceasing to vocalize.
Many animals will combine several of these strategies to compensate
for high levels of background noise. Anthropogenic sounds that reduce
the signal-to-noise ratio of animal vocalizations, increase the masked
auditory thresholds of animals listening for such vocalizations, or
reduce the active space of an animal's vocalizations impair
communication between animals. Most animals that vocalize have evolved
strategies to compensate for the effects of short-term or temporary
increases in background or ambient noise on their songs or calls.
Although the fitness consequences of these vocal adjustments are not
directly known in all instances, like most other trade-offs animals
must make, some of these strategies likely come at a cost (Patricelli
et al., 2006; Noren et al., 2017; Noren et al., 2020). Shifting songs
and calls to higher frequencies may also impose energetic costs
(Lambrechts, 1996).
Marine mammals are also known to make vocal changes in response to
anthropogenic noise. In cetaceans, vocalization changes have been
reported from exposure to anthropogenic noise sources such as sonar,
vessel noise, and seismic surveying (see the following for examples:
Gordon et al., 2003; Di Iorio and Clark, 2009; Hatch et al., 2012; Holt
et al., 20098; Holt et al., 2011; Lesage et al., 1999; McDonald et al.,
2009; Parks et al., 2007, Risch et al., 2012, Rolland et al., 2012), as
well as changes in the natural acoustic environment (Dunlop et al.,
2014). Vocal changes can be temporary, or can be persistent. For
example, model simulation suggests that the increase in starting
frequency for the North Atlantic right whale upcall over the last 50
years resulted in increased detection ranges between right whales. The
frequency shift, coupled with an increase in call intensity by 20 dB,
led to a call detectability range of less than 3 km to over 9 km
(Tennessen and Parks, 2016). Holt et al. (2009) measured killer whale
call source levels and background noise levels in the one to 40 kHz
band and reported that the whales increased their call source levels by
one dB SPL for every one dB SPL increase in background noise level.
Similarly, another study on St. Lawrence River belugas reported a
similar rate of increase in vocalization activity in response to
passing vessels (Scheifele et al., 2005). Di Iorio and Clark (2009)
showed that blue whale calling rates vary in association with seismic
sparker survey activity, with whales calling more on days with surveys
than on days without surveys. They suggested that the whales called
more during seismic survey periods as a way to compensate for the
elevated noise conditions.
In some cases, these vocal changes may have fitness consequences,
such as an increase in metabolic rates and oxygen consumption, as
observed in bottlenose dolphins when increasing their call amplitude
(Holt et al., 2015). A switch from vocal communication to physical,
surface-generated sounds such as pectoral fin slapping or breaching was
observed for humpback whales in the presence of increasing natural
background noise levels, indicating that adaptations to masking may
also move beyond vocal modifications (Dunlop et al., 2010).
While these changes all represent possible tactics by the sound-
producing animal to reduce the impact of masking, the receiving animal
can also reduce masking by using active listening strategies such as
orienting to the sound source, moving to a quieter location, or
reducing self-noise from hydrodynamic flow by remaining still. The
temporal structure of noise (e.g., amplitude modulation) may also
provide a considerable release from masking through comodulation
masking release (a reduction of masking that occurs when broadband
noise, with a frequency spectrum wider than an animal's auditory filter
bandwidth at the frequency of interest, is amplitude modulated)
(Branstetter and Finneran, 2008; Branstetter et al., 2013). Signal type
(e.g., whistles, burst-pulse, sonar clicks) and spectral
characteristics (e.g., frequency modulated with harmonics) may further
influence masked detection thresholds (Branstetter et al., 2016;
Cunningham et al., 2014).
Masking is more likely to occur in the presence of broadband,
relatively continuous noise sources such as vessels. Several studies
have shown decreases in marine mammal communication space and changes
in behavior as a result of the presence of vessel noise. For example,
right whales were observed to shift the frequency content of their
calls upward while reducing the rate of calling in areas of increased
anthropogenic noise (Parks et al., 2007) as well as increasing the
amplitude (intensity) of their calls (Parks, 2009; Parks et al., 2011).
Clark et al. (2009) observed that right whales' communication space
decreased by up to 84 percent in the presence of vessels. Cholewiak et
al. (2018) also observed loss in communication space in Stellwagen
National Marine Sanctuary for North Atlantic right whales, fin whales,
and humpback whales with increased ambient noise and shipping noise.
Although humpback whales off Australia did not change the frequency or
duration of their vocalizations in the presence of ship noise, their
source levels were lower than expected based on source level changes to
wind noise, potentially indicating some signal masking (Dunlop, 2016).
Multiple delphinid species have also been shown to increase the minimum
or maximum frequencies of their whistles in the presence of
anthropogenic noise and reduced communication space (for examples see:
Holt et al., 20098; Holt et al., 2011; Gervaise et al., 2012; Williams
et al., 2013; Hermannsen et al., 2014; Papale et al., 2015; Liu et al.,
2017). While masking impacts are not a concern from lower intensity,
higher frequency HRG surveys, some degree of masking would be expected
in the vicinity of turbine pile driving and concentrated support vessel
operation. However, pile driving is an intermittent sound and would not
be continuous throughout a day.
Habituation and Sensitization
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). 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

[[Page 22721]]

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 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). Stone (2015a)
reported data from at-sea observations during 1,196 airgun surveys from
1994 to 2010. When large arrays of airguns (considered to be 500 in 3
or more) were firing, lateral displacement, more localized avoidance,
or other changes in behavior were evident for most odontocetes.
However, significant responses to large arrays were found only for the
minke whale and fin whale. Behavioral responses observed included
changes in swimming or surfacing behavior with indications that
cetaceans remained near the water surface at these times. Behavioral
observations of gray whales during an air gun survey monitored whale
movements and respirations pre-, during-, and post-seismic survey
(Gailey et al., 2016). Behavioral state and water depth were the best
`natural' predictors of whale movements and respiration and after
considering natural variation, none of the response variables were
significantly associated with survey or vessel sounds. Many delphinids
approach low-frequency airgun source vessels with no apparent
discomfort or obvious behavioral change (e.g., Barkaszi et al., 2012),
indicating the importance of frequency output in relation to the
species' hearing sensitivity.
Physiological Responses
An animal's perception of a threat may be sufficient to trigger
stress responses consisting of some combination of behavioral
responses, autonomic nervous system responses, neuroendocrine
responses, or immune responses (e.g., 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
sufficiently to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied 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.
These and other studies lead to a reasonable expectation that some
marine mammals will experience physiological stress responses upon
exposure to acoustic stressors and that it is possible that some of
these would be classified as ``distress.'' In addition, any animal
experiencing TTS would likely also experience stress responses (NRC,
2003, 2017).
Respiration naturally varies with different behaviors and
variations in respiration rate as a function of acoustic exposure can
be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Mean exhalation rates of gray whales at rest and while
diving were found to be unaffected by seismic surveys conducted
adjacent to the whale feeding grounds (Gailey et al., 2007). Studies
with captive harbor porpoises show increased respiration rates upon
introduction of acoustic alarms (Kastelein et al., 2001; 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.

Potential Effects of Disturbance on Marine Mammal Fitness

The different ways that marine mammals respond to sound are
sometimes indicators of the ultimate effect that exposure to a given
stimulus will have on the well-being (survival, reproduction, etc.) of
an animal. There is little quantitative marine mammal data relating the
exposure of marine mammals from sound to effects on reproduction or
survival, though data exists for terrestrial species to which we can
draw comparisons for marine mammals. Several authors have reported that
disturbance stimuli may cause animals to abandon nesting and foraging
sites (Sutherland and Crockford, 1993); may cause animals to increase
their activity levels and suffer premature deaths or reduced
reproductive success when their energy expenditures exceed their energy
budgets (Daan et al., 1996; Feare, 1976; Mullner et al., 2004); or may
cause animals to experience higher predation rates when they adopt
risk-prone foraging or migratory strategies (Frid

[[Page 22722]]

and Dill, 2002). Each of these studies addressed the consequences of
animals shifting from one behavioral state (e.g., resting or foraging)
to another behavioral state (e.g., avoidance or escape behavior)
because of human disturbance or disturbance stimuli.
Attention is the cognitive process of selectively concentrating on
one aspect of an animal's environment while ignoring other things
(Posner, 1994). Because animals (including humans) have limited
cognitive resources, there is a limit to how much sensory information
they can process at any time. The phenomenon called ``attentional
capture'' occurs when a stimulus (usually a stimulus that an animal is
not concentrating on or attending to) ``captures'' an animal's
attention. This shift in attention can occur consciously or
subconsciously (for example, when an animal hears sounds that it
associates with the approach of a predator) and the shift in attention
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has
captured an animal's attention, the animal can respond by ignoring the
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus
as a disturbance and respond accordingly, which includes scanning for
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
Vigilance is an adaptive behavior that helps animals determine the
presence or absence of predators, assess their distance from
conspecifics, or to attend cues from prey (Bednekoff and Lima, 1998;
Treves, 2000). Despite those benefits, however, vigilance has a cost of
time; when animals focus their attention on specific environmental
cues, they are not attending to other activities such as foraging or
resting. These effects have generally not been demonstrated for marine
mammals, but studies involving fish and terrestrial animals have shown
that increased vigilance may substantially reduce feeding rates (Saino,
1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002; Purser and
Radford, 2011). Animals will spend more time being vigilant, which may
translate to less time foraging or resting, when disturbance stimuli
approach them more directly, remain at closer distances, have a greater
group size (e.g., multiple surface vessels), or when they co-occur with
times that an animal perceives increased risk (e.g., when they are
giving birth or accompanied by a calf).
The primary mechanism by which increased vigilance and disturbance
appear to affect the fitness of individual animals is by disrupting an
animal's time budget and, as a result, reducing the time they might
spend foraging and resting (which increases an animal's activity rate
and energy demand while decreasing their caloric intake/energy). In a
study of northern resident killer whales off Vancouver Island, exposure
to boat traffic was shown to reduce foraging opportunities and increase
traveling time (Holt et al., 2021). A simple bioenergetics model was
applied to show that the reduced foraging opportunities equated to a
decreased energy intake of 18 percent while the increased traveling
incurred an increased energy output of 3-4 percent, which suggests that
a management action based on avoiding interference with foraging might
be particularly effective.
On a related note, many animals perform vital functions, such as
feeding, resting, traveling, and socializing, on a diel cycle (24-hr
cycle). Behavioral reactions to noise exposure (such as disruption of
critical life functions, displacement, or avoidance of important
habitat) are more likely to be significant for fitness if they last
more than one diel cycle or recur on subsequent days (Southall et al.,
2007). Consequently, a behavioral response lasting less than one day
and not recurring on subsequent days is not considered particularly
severe unless it could directly affect reproduction or survival
(Southall et al., 2007). It is important to note the difference between
behavioral reactions lasting or recurring over multiple days and
anthropogenic activities lasting or recurring over multiple days. For
example, just because certain activities last for multiple days does
not necessarily mean that individual animals will be either exposed to
those activity-related stressors (i.e., sonar) for multiple days or
further exposed in a manner that would result in sustained multi-day
substantive behavioral responses. However, special attention is
warranted where longer-duration activities overlay areas in which
animals are known to congregate for longer durations for biologically
important behaviors.
As noted above, there are few studies that directly illustrate the
impacts of disturbance on marine mammal populations. Lusseau and Bejder
(2007) present data from three long-term studies illustrating the
connections between disturbance from whale-watching boats and
population-level effects in cetaceans. In Shark Bay, Australia, the
abundance of bottlenose dolphins was compared within adjacent control
and tourism sites over three consecutive 4.5-year periods of increasing
tourism levels. Between the second and third time periods, in which
tourism doubled, dolphin abundance decreased by 15 percent in the
tourism area and did not change significantly in the control area. In
Fiordland, New Zealand, two populations (Milford and Doubtful Sounds)
of bottlenose dolphins with tourism levels that differed by a factor of
seven were observed and significant increases in traveling time and
decreases in resting time were documented for both. Consistent short-
term avoidance strategies were observed in response to tour boats until
a threshold of disturbance was reached (average 68 minutes between
interactions), after which the response switched to a longer-term
habitat displacement strategy. For one population, tourism only
occurred in a part of the home range. However, tourism occurred
throughout the home range of the Doubtful Sound population and once
boat traffic increased beyond the 68-minute threshold (resulting in
abandonment of their home range/preferred habitat), reproductive
success drastically decreased (increased stillbirths) and abundance
decreased significantly (from 67 to 56 individuals in a short period).
In order to understand how the effects of activities may or may not
impact species and stocks of marine mammals, it is necessary to
understand not only what the likely disturbances are going to be but
how those disturbances may affect the reproductive success and
survivorship of individuals and then how those impacts to individuals
translate to population-level effects. Following on the earlier work of
a committee of the U.S. National Research Council (NRC, 2005), New et
al. (2014), in an effort termed the Potential Consequences of
Disturbance (PCoD), outline an updated conceptual model of the
relationships linking disturbance to changes in behavior and
physiology, health, vital rates, and population dynamics. This
framework is a four-step process progressing from changes in individual
behavior and/or physiology, to changes in individual health, then vital
rates, and finally to population-level effects. In this framework,
behavioral and physiological changes can have direct (acute) effects on
vital rates, such as when changes in habitat use or increased stress
levels raise the probability of mother-calf separation or predation;
indirect and long-term (chronic) effects on vital rates, such as when
changes in time/energy budgets or increased disease susceptibility
affect health, which then affects vital rates; or no effect to vital
rates (New et al., 2014). Since this general framework was outlined and
the relevant supporting

[[Page 22723]]

literature compiled, multiple studies developing state-space energetic
models for species with extensive long-term monitoring (e.g., southern
elephant seals, North Atlantic right whales, Ziphiidae beaked whales,
and bottlenose dolphins) have been conducted and can be used to
effectively forecast longer-term, population-level impacts from
behavioral changes. While these are very specific models with very
specific data requirements that cannot yet be applied broadly to
project-specific risk assessments for the majority of species, they are
a critical first step towards being able to quantify the likelihood of
a population level effects. Since New et al. (2014), several
publications have described models developed to examine the long-term
effects of environmental or anthropogenic disturbance of foraging on
various life stages of selected species (e.g., sperm whale, Farmer et
al. (2018); California sea lion, McHuron et al. (2018); blue whale,
Pirotta et al. (2018a); humpback whale, Dunlop et al. (2021)). These
models continue to add to refinement of the approaches to the PCoD
framework. Such models also help identify what data inputs require
further investigation. Pirotta et al. (2018b) provides a review of the
PCoD framework with details on each step of the process and approaches
to applying real data or simulations to achieve each step.
D

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