[Federal Register Volume 89, Number 3 (Thursday, January 4, 2024)]
[Proposed Rules]
[Pages 504-587]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-27189]



[[Page 503]]

Vol. 89

Thursday,

No. 3

January 4, 2024

Part II





 Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 217





Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to the Maryland Offshore Wind Project 
Offshore of Maryland; Proposed Rule

Federal Register / Vol. 89 , No. 3 / Thursday, January 4, 2024 / 
Proposed Rules

[[Page 504]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 231206-0289]
RIN 0648-BM32


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Maryland Offshore Wind Project 
Offshore of Maryland

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS has received a request from US Wind, Inc., (US Wind) for 
Incidental Take Regulations (ITR) and an associated Letter of 
Authorization (LOA) pursuant to the Marine Mammal Protection Act 
(MMPA). The requested regulations would govern the authorization of 
take, by Level A harassment and Level B harassment, of small number of 
marine mammals over the course of 5 years (2025-2029) incidental to 
construction of the Maryland Offshore Wind Project offshore of Maryland 
within the Bureau of Ocean Energy Management (BOEM) Commercial Lease of 
Submerged Lands for Renewable Energy Development on the Outer 
Continental Shelf (OCS) Lease Area OCS-A 0490 (Lease Area) and 
associated Export Cable Routes. Project activities likely to result in 
incidental take include impact pile driving and site assessment surveys 
using high-resolution geophysical (HRG) equipment. NMFS requests 
comments on its proposed rule. NMFS will consider public comments prior 
to making any final decision on the promulgation of the requested ITR 
and issuance of the LOA; agency responses to public comments will be 
summarized in the final notice of our decision. The proposed 
regulations, if issued, would be effective January 1, 2025 through 
December 31, 2029.

DATES: Comments and information must be received no later than February 
5, 2024.

ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to https://www.regulations.gov and enter NOAA-
NMFS-2023-0110 in the Search box. (note: copying and pasting the FDMS 
Docket Number directly from this document may not yield search 
results). 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 
https://www.regulations.gov 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).

FOR FURTHER INFORMATION CONTACT: Jessica Taylor, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

    A copy of US Wind's Incidental Take Authorization (ITA) application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. In case of 
problems accessing these documents, please call the contact listed 
above (see FOR FURTHER INFORMATION CONTACT).

Purpose and Need for Regulatory Action

    This proposed rule would provide a framework under the authority of 
the MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of 
take of marine mammals incidental to construction of the Maryland 
Offshore Wind Project (hereafter, ``Project'') within the BOEM 
Renewable Energy Development Lease Area and along export cable 
corridors to landfall locations in Delaware. NMFS received a request 
from US Wind for 5-year regulations and a LOA that would authorize take 
of individuals of 19 species of marine mammals (5 species by Level A 
harassment and Level B harassment and 14 species by Level B harassment 
only), comprising 20 stocks, incidental to US Wind's construction 
activities. No mortality or serious injury is anticipated or proposed 
for authorization. Please see below for definitions of harassment. 
Please see the Estimated Take of Marine Mammals section below for 
definitions of relevant terms.

Legal Authority for the Proposed Action

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made, regulations are 
promulgated (when applicable), 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, the availability of the species or stocks for taking for 
certain subsistence uses (referred to as ``mitigation''), and 
requirements pertaining to the mitigation, monitoring and reporting of 
the takings are set forth.
    As noted above, no serious injury or mortality is anticipated or 
proposed for authorization in this proposed rule. Relevant definitions 
of MMPA statutory and regulatory terms are included below:
    <bullet> Citizen--individual U.S. citizens or any corporation or 
similar entity if it is organized under the laws of the United States 
or any governmental unit defined in 16 U.S.C. 1362(13) (50 CFR 
216.103);
    <bullet> Take--to harass, hunt, capture, or kill, or attempt to 
harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362; 50 
CFR 216.3);
    <bullet> Incidental taking--an accidental taking. This does not 
mean that the taking is unexpected, but rather it includes those 
takings that are infrequent, unavoidable, or accidental (50 CFR 
216.103);
    <bullet> Serious injury--any injury that will likely result in 
mortality (50 CFR 216.3);
    <bullet> Level A harassment--any act of pursuit, torment, or 
annoyance which has the potential to injure a marine mammal or marine 
mammal stock in the wild (16 U.S.C. 1362); and
    <bullet> Level B harassment--any act of pursuit, torment, or 
annoyance which has the potential to disturb a marine

[[Page 505]]

mammal or marine mammal stock in the wild by causing disruption of 
behavioral patterns, including, but not limited to, migration, 
breathing, nursing, breeding, feeding, or sheltering (16 U.S.C. 1362).
    Section 101(a)(5)(A) of the MMPA and the implementing regulations 
at 50 CFR part 216, subpart I, provide the legal basis for proposing 
and, if appropriate, issuing 5-year regulations and associated LOA. 
This proposed rule also establishes required mitigation, monitoring, 
and reporting requirements for US Wind's activities.

Summary of Major Provisions Within the Proposed Action

    The major provisions within this proposed rule are as follows:
    <bullet> Authorize take of marine mammals by Level A harassment 
and/or Level B harassment;
    <bullet> No mortality or serious injury of any marine mammal is 
proposed to be authorized;
    <bullet> Establish a seasonal moratorium on pile driving during the 
months of highest North Atlantic right whale (Eubalaena glacialis) 
presence in the project area (December 1-April 30);
    <bullet> Require both visual and passive acoustic monitoring by 
trained, NMFS-approved Protected Species Observers (PSOs) and Passive 
Acoustic Monitoring (PAM) operators before, during, and after impact 
pile driving and HRG surveys;
    <bullet> Require training for all US Wind personnel that would 
clearly articulate all relevant responsibilities, communication 
procedures, marine mammal monitoring and mitigation protocols, 
reporting protocols, safety, operational procedures, and requirements 
of the ITA and ensure that all requirements are clearly understood by 
all participating parties;
    <bullet> Require the use of sound attenuation device(s) during all 
foundation installation activities to reduce noise levels;
    <bullet> Delay the start of foundation installation if a North 
Atlantic right whale is observed at any distance by a PSO or 
acoustically detected within certain distances;
    <bullet> Delay the start of foundation installation if other marine 
mammals are observed entering or within their respective clearance 
zones;
    <bullet> Shut down pile driving (if feasible) if a North Atlantic 
right whale is observed or if other marine mammals enter their 
respective shut down zones;
    <bullet> Shut down HRG survey equipment that may impact marine 
mammals if a marine mammal enters their respective shut down zones;
    <bullet> Conduct sound field verification during impact pile 
driving to ensure in situ noise levels are not exceeding those modeled;
    <bullet> Implement soft starts for impact pile driving;
    <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 very high-frequency 
(VHF) Channel 16, as well as reporting any sightings to the sighting 
network;
    <bullet> Implement various vessel strike avoidance measures;
    <bullet> Implement Best Management Practices (BMPs) during 
fisheries monitoring surveys, such as removing gear from the water if 
marine mammals are considered at-risk or are interacting with gear; and
    <bullet> Require frequent scheduled and situational reporting 
including, but not limited to, information regarding activities 
occurring, marine mammal observations and acoustic detections, and 
sound field verification monitoring results.
    Under section 105(a)(1) of the MMPA, failure to comply with these 
requirements or any other requirements in a regulation or permit 
implementing the MMPA may result in civil monetary penalties. Pursuant 
to 50 CFR 216.106, violations may also result in suspension or 
withdrawal of the LOA for the project. Knowing violations may result in 
criminal penalties under section 105(b) of the MMPA.

National Environmental Policy Act (NEPA)

    To comply with the National Environmental Policy Act of 1969 (NEPA) 
(42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must evaluate the proposed action (i.e., promulgation of 
regulations and subsequent issuance of a 5-year LOA) and alternatives 
with respect to potential impacts on the human environment.
    Accordingly, NMFS plans to adopt the BOEM 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, ``Maryland Offshore Wind Project Draft Environmental Impact 
Statement (DEIS) for Commercial Wind Lease OCS-A 0490'', was made 
available for public comment on October 6, 2023 (88 FR 69658) and is 
available at https://www.boem.gov/renewable-energy/state-activities/maryland-offshore-wind. The DEIS had a 45-day public comment period 
open from October 6, 2023 to November 20, 2023. Additionally, BOEM held 
two in-person public meetings on October 24, 2023 in Ocean City, 
Maryland and October 26, 2023 in Dagsboro, Delaware and two virtual 
public meetings on October 19, 2023 and October 30, 2023.
    Information contained within US Wind's ITA application and this 
Federal Register document provide the environmental information related 
to these proposed regulations and associated 5-year LOA for public 
review and comment. NMFS will review all comments submitted in response 
to this notice of proposed rulemaking prior to concluding the NEPA 
process or making a final decision on the requested 5-year ITR and LOA.

Fixing America's Surface Transportation Act (FAST-41)

    This project is covered under Title 41 of the Fixing America's 
Surface Transportation Act, or ``FAST-41.'' FAST-41 includes a suite of 
provisions designed to expedite the environmental review for covered 
infrastructure projects, including enhanced interagency coordination as 
well as milestone tracking on the public-facing Permitting Dashboard. 
FAST-41 also places a 2-year limitations period on any judicial claim 
that challenges the validity of a Federal agency decision to issue or 
deny an authorization for a FAST-41 covered project (42 U.S.C. 4370m-
6(a)(1)(A)).
    US Wind's proposed project is listed on the Permitting Dashboard. 
Milestones and schedules related to the environmental review and 
permitting for the US Wind's Maryland Offshore Wind Project can be 
found at https://www.permits.performance.gov/permitting-project/maryland-offshore-wind-project.

Summary of Request

    On August 31, 2022, NMFS received a request from US Wind, a 
Baltimore, Maryland-based company registered in the State of Delaware 
and subsidiary of Renexia SpA, 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 
Project offshore of Maryland in the BOEM Lease Area OCS-A 0490 and 
associated export cable routes. The request was for the incidental, but 
not intentional, taking of a small number of 19 marine mammal species 
(comprising 20 stocks). Neither

[[Page 506]]

US Wind nor NMFS expects serious injury or mortality to result from the 
specified activities nor is any proposed for authorization.
    US Wind is proposing to develop the Project over the course of 
three construction campaigns. In total, the 3 campaigns would result in 
a maximum of 114 wind turbine generators (WTGs), 4 offshore substations 
(OSS) positions, and 1 Meteorological tower (Met tower) within the 
Lease Area. The initial construction campaign, MarWin, would include 
installation of approximately 21 WTGs, 1 OSS, and cable landing 
infrastructure during the first year of activities in the most eastern 
part of the Lease Area. The second construction campaign, Momentum 
Wind, would take place during the second year of construction 
activities and include installation of approximately 55 WTGs, 2 OSSs, 
and a Met tower immediately to the west of MarWin. The third 
construction campaign, currently unnamed and referred to as Future 
Development, would occur during the third year of construction 
activities and include the installation of approximately 38 WTGs and 1 
OSS in the most western portion of the Lease Area. Four offshore export 
cables would transmit electricity generated by the WTGs from the Lease 
Area to onshore transmission systems within Delaware Seashore State 
Park.
    In response to our comments and following extensive information 
exchanges with NMFS, US Wind submitted a final, revised application on 
March 31, 2023 that NMFS deemed adequate and complete on April 3, 2023. 
The final version of the application is available on NMFS' website at: 
https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-wind-inc-construction-and-operation-maryland-offshore-wind. On May 2, 
2023, NMFS published a notice of receipt (NOR) of the adequate and 
complete application in the Federal Register (88 FR 27463), requesting 
comments and soliciting information related to US Wind's request during 
a 30-day public comment period. During the NOR public comment period, 
NMFS received comment letters from 77 private citizens, 6 non-
governmental organizations, and 1 state government organization 
(Delaware Department of Natural Resources and Environmental Control). 
NMFS has reviewed all submitted material and has taken these into 
consideration during the drafting of this proposed rule.
    On August 1, 2022, NMFS announced proposed changes to the existing 
North Atlantic right whale vessel speed regulations (87 FR 46921, 
August 1, 2022) to further reduce the likelihood of mortalities and 
serious injuries to endangered right whales from vessel collisions, 
which are a leading cause of the species' decline and a primary factor 
in an ongoing Unusual Mortality Event (UME). Should a final vessel 
speed rule be issued and become effective during the effective period 
of this ITR (or any other MMPA incidental take authorization), the 
authorization holder would be required to comply with any and all 
applicable requirements contained within the final rule. Specifically, 
where measures in any final vessel speed rule are more protective or 
restrictive than those in this or any other MMPA authorization, 
authorization holders would be required to comply with the requirements 
of the rule. Alternatively, where measures in this or any other MMPA 
authorization are more restrictive or protective than those in any 
final vessel speed rule, the measures in the MMPA authorization would 
remain in place. The responsibility to comply with the applicable 
requirements of any vessel speed rule would become effective 
immediately upon the effective date of any final vessel speed rule and 
when notice is published on the effective date, NMFS would also notify 
US Wind if the measures in the speed rule were to supersede any of the 
measures in the MMPA authorization such that they were no longer 
required.
    On September 6, 2023, and September 11, 2023, US Wind submitted 
supplemental information related to its pilot whale and seal take 
analyses. The corresponding memos, entitled ``US Wind NMFS Request for 
Information (RFI) Response Memo and Maryland Offshore Wind Project 
Revised Requested Take Tables'' are available on our website.

Description of the Specified Activities

Overview

    US Wind has proposed to construct and operate a wind energy 
facility, the Project, in the Atlantic Ocean in lease area OCS-A 0490, 
offshore Maryland. The Project would allow the State of Maryland to 
advance Federal and State offshore wind targets as well as reduce 
greenhouse gas emissions, increase grid reliability, and support 
economic development growth in the region. The Project consists of 
three construction campaigns including MarWin, located in the 
southeastern portion of the Lease Area with the potential to generate 
approximately 300 megawatts (MW) of energy, Momentum Wind, located 
immediately west of MarWin with the potential to generate approximately 
808 MW of energy, and Future Development, which encompasses buildout of 
the remainder of the Lease Area and for which generation capacity has 
yet to be determined. Once operational, MarWin and Momentum Wind would 
advance the State of Maryland's renewable energy goals of 50 percent by 
the year 2030, with the full buildout of the Lease Area further 
achieving renewable energy targets. US Wind also anticipates completing 
the Future Development campaign within the effective period of the 
proposed rule.
    The Project would consist of several different types of permanent 
offshore infrastructure, including up to 114 WTGs (e.g., 18-MW model 
with a 250-meter (m) rotor diameter platform), four OSSs, a Met tower, 
and inter-array and export cables. The Project is divided into three 
construction campaigns: MarWin, Momentum Wind, and Future Development 
(table 1). MarWin would occupy approximately 46.6 km\2\ (11,515 acres) 
which would include approximately 21 WTGs and 1 OSS. The MarWin 
campaign, as well as subsequent Momentum Wind and Future Development, 
includes monopiles as the one potential WTG foundation type. For each 
campaign, the OSS would be supported by monopiles or jacket foundations 
with skirt piles. Skirt piles are post-piled pin piles. Jacket 
foundations are placed on the seabed and pin piles are driven into 
jacket pile guides, which are known as skirts. Table 1 provides a 
summary of each construction campaign.

                                              Table 1--US Wind's Anticipated Construction Campaign Schedule
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Number of 11-m                                Number of 1.8-
                Campaigns                   Construction     monopiles for     Number 3-m pin piles for     m pin piles    Onshore export     Offshore
                                                year             WTGs         OSS jacket foundations \1\   for Met tower       cables        substations
--------------------------------------------------------------------------------------------------------------------------------------------------------
MarWin...................................        1 (2025)                21  4 (1 jacket)...............               0                 4             1
Momentum.................................        2 (2026)                55  8 (2 jackets)..............               3                 0             2

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Future Development.......................        3 (2027)                38  4 (1 jacket)...............               0                 0             1
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\1\ Potential OSS foundations could also include monopile and suction bucket jacket foundations.

    Strings of WTGs will connect with the OSS via a submarine inter-
array cable transmission system. Up to four high-voltage alternating 
current (HVAC) offshore export cables would be installed during the 
MarWin campaign, spanning approximately 65-97 km (40-60 miles (mi)) in 
length, dependent on the location of the OSS and the final routing. The 
Export Cable Corridor (ECC) would transmit electricity from the OSS to 
one or two landfall sites in Delaware Seashore State Park.
    The second construction campaign, Momentum Wind, would contain 
approximately 55 WTGs, 2 OSSs, and 1 Met tower within an area of 
approximately 142.4 km\2\ (35,188 acres). The Met tower would be 
supported by pin pile foundations. During the third construction 
campaign, Future Development, approximately 38 WTGs and 1 OSS would be 
installed within an area of approximately 80.3 km\2\ (19,843 acres).
    US Wind plans to install all monopile or pin pile foundations via 
impact pile driving. If suction bucket foundations are selected for OSS 
jacket foundations, impact pile driving would not be necessary. US Wind 
would also conduct the following supporting activities: temporary 
installation and subsequent removal of gravity cells to connect the 
offshore export cables to onshore facilities; permanently install scour 
protection around all foundations; permanently install and perform 
trenching, laying, and burial activities associated with the export 
cables from the OSSs to shore-based switching and sub-stations and WTG 
inter-array cables; and, during years 2 and 3, performance of HRG 
surveys using active acoustic sources with frequencies of less than 180 
kilohertz (kHz). Vessels would transit within the project area and 
anticipated between ports (Port Norris, NJ; Lewes, DE; Ocean City, MD; 
Baltimore, MD; Hampton Roads, VA; and Cape Charles, VA) and the Lease 
Area and cable corridors to transport crew, supplies, and materials to 
support construction activities.
    Up to four offshore export cables would be located among up to two 
corridors from the OSSs and connect to the planned landfall at either 
3R's Beach or Tower Road within Delaware Seashore State Park. When the 
cables reach the landfall site, they would be pulled into a cable duct 
generated by horizontal directional drilling (HDD), which would route 
the cables under the existing beach to subterranean transition vaults. 
All offshore cables would be connected to onshore export cables at the 
sea-to-shore transition point via trenchless installation (i.e., 
underground tunneling utilizing micro tunnel boring installation 
methodologies).
    Fishery monitoring surveys, performed via recreational boat-based 
surveys and a pot-based monitoring approach using ropeless gear 
technology, would be conducted in conjunction with the University of 
Maryland Center for Environmental Science (UMCES) to enhance existing 
data for specific benthic and pelagic species of concern.

Dates and Duration

    As described above, US Wind would conduct 3 campaigns over 3 years: 
MarWin, Momentum Wind, and Future Development (table 1). In case of any 
delays to any campaign, NMFS is proposing a 5-year effective date of 
the proposed regulations and LOA; however, no more work in any given 
year or total over 5 years other than described here would occur. US 
Wind anticipates that activities with the potential to result in 
incidental take of marine mammals would occur throughout 3 of the 5 
years (2025-2027) of the proposed regulations which, if issued, would 
be effective from January 1, 2025 through December 31, 2029. Based on 
US Wind's proposed schedule, the installation of all permanent 
structures would be completed by the end of November 2027. More 
specifically, US Wind would install piles only between May 1 and 
November 30. Also, the installation of WTG foundations and OSS 3-m pin 
pile jacket foundations is expected to occur during daylight hours 
between May 1 and November 30 of 2025, 2026, and 2027 (table 2); 
however, NMFS is proposing to allow nighttime pile driving if US Wind 
submits, and NMFS approves, an Alternative Monitoring Plan, as 
discussed below. The single Met tower foundation would be installed in 
2026 (table 2).
    US Wind anticipates HRG surveys using sparkers and boomers to occur 
during 2026 and 2027. Up to 14 days of HRG survey activity are planned 
from April through June 2026 during the Momentum campaign. In addition, 
up to 14 days of HRG survey activity are planned from April through 
June 2027 during the Future Development campaign. No HRG surveys using 
equipment that has the potential to result in the harassment of marine 
mammals (e.g., sparkers or boomers) are planned for the MarWin campaign 
during year 1.

 Table 2--US Wind's Anticipated Construction and Operations Schedule During the Effective Period of the LOA \1\
----------------------------------------------------------------------------------------------------------------
                                                                                              Expected duration
         Project activity                 Construction campaign         Expected timing \2\     (approximate)
----------------------------------------------------------------------------------------------------------------
Scour Protection Pre-Installation  MarWin.............................  Year 1: Q2 through   21 days.
                                                                         Q3 of 2025.
                                   Momentum Wind......................  Year 2: Q2 through   55 days.
                                                                         Q3 of 2026.
                                   Future Development.................  Year 3: Q2 through   38 days.
                                                                         Q3 of 2027.
WTG Foundation Installation 3 5..  MarWin.............................  Year 1: June         21 days.
                                                                         through September
                                                                         of 2025.
                                   Momentum Wind......................  Year 2: May through  55 days.
                                                                         August of 2026.
                                   Future Development.................  Year 3: June         38 days.
                                                                         through August of
                                                                         2027.
Scour Protection Post-             MarWin.............................  Year 1: Q2 through   42 days.
 Installation.                                                           Q3 of 2025.
                                   Momentum Wind......................  Year 2: Q2 through   110 days.
                                                                         Q3 of 2026.
                                   Future Development.................  Year 3: Q2 through   76 days.
                                                                         Q3 of 2027.
OSS Foundation Installation 3 5..  MarWin.............................  Year 1: July of      1 day.
                                                                         2025.

[[Page 508]]

 
                                   Momentum Wind......................  Year 2: July of      2 days.
                                                                         2026.
                                   Future Development.................  Year 3: July of      1 day.
                                                                         2027.
Met Tower Installation 3 4.......  Momentum Wind......................  Year 2: June of      1 day.
                                                                         2026.
HRG Surveys \5\..................  Momentum Wind......................  Year 2: Q2 through   14 days.
                                                                         Q3 of 2026.
                                   Future Development.................  Year 3: Q2 through   14 days.
                                                                         Q3 of 2027.
Site Preparation.................  n/a................................  Not anticipated....  n/a.
Inter-array Cable Installation...  Marwin.............................  Year 1: Q2 through   42 days.
                                                                         Q4 of 2025.
                                   Momentum Wind......................  Year 2: Q2 through   110 days.
                                                                         Q4 of 2026.
                                   Future Development.................  Year 3: Q2 through   76 days.
                                                                         Q4 of 2027.
Export Cable Installation........  MarWin.............................  Year 1: Q1 through   60 days.
                                                                         Q4 of 2025.
                                   Momentum Wind......................  Year 2: Q1 through   120 days (2
                                                                         Q4 of 2026.          cables).
                                   Future Development.................  Year 3: Q1 through   60 days.
                                                                         Q4 of 2027.
Fishery Monitoring Surveys.......  MarWin.............................  Q1 through Q4 Years  16 days/year for
                                                                         1-5.                 commercial pot
                                                                                              surveys.
                                   Momentum Wind......................                       12 days/year for
                                   Future Development.................                        recreational
                                                                                              surveys.
----------------------------------------------------------------------------------------------------------------
\1\ While the effective period of the proposed regulations would extend through December 31, 2029, no activities
  are proposed to occur in 2028 or 2029 by US Wind so these were not included in this table.
\2\ Installation timing will depend on vessel availability, contractor selection, weather, and more. Year 1 is
  anticipated to be 2025, year 2 to be 2026, and year 3 to be 2027, although these are subject to change per the
  factors identified. Note: ``Q1, Q2, Q3, and Q4'' each refer to a quarter of the year, starting in January and
  comprising 3 months each. Therefore, Q1 represents January through March, Q2 represents April through June, Q3
  represents July through September, and Q4 represents October through December.
\3\ The months identified here represent US Wind's planned schedule; however, in case of unanticipated delays,
  foundation installation may occur between May 1 and November 30 annually.
\4\ US Wind anticipates that all WTGs, OSS, and Met tower foundations will be installed by November 30, 2027;
  however, unanticipated delays may require some foundation pile driving to occur in years 4 (2028) or 5 (2029).
\5\ Represents HRG surveys that may result in take of marine mammals. US Wind plans to conduct HRG surveys that
  do not have the potential to result in take of marine mammals during Q2 through Q3 of year 1 given those
  surveys would utilize equipment all operating over 180kHz or have no acoustic output.

Specific Geographic Region

    US Wind's specified activities would occur within the Northeast 
U.S. Continental Shelf Large Marine Ecosystem (NES LME), an area of 
approximately 260,000 km\2\ (64,247,399.2 acres) from Cape Hatteras in 
the south to the Gulf of Maine in the north. Specifically, the 
specified geographic region is the Middle-Atlantic Bight (Mid-Atlantic 
Bight) sub-area of the NES LME. The Mid-Atlantic Bight encompasses 
waters of the Atlantic Ocean between Cape Hatteras, North Carolina and 
Martha's Vineyard, Massachusetts, extending westward into the Atlantic 
to the 100-m isobath. In the Mid-Atlantic Bight, the pattern of 
sediment distribution is relatively simple. The continental shelf south 
of New England is broad and flat, dominated by fine grained sediments. 
Most of the surficial sediments on the continental shelf are sands and 
gravels. Silts and clays predominate at and beyond the shelf edge, with 
most of the slope being 70-100 percent mud. Fine sediments are also 
common in the shelf valleys leading to the submarine canyons. There are 
some larger materials, left by retreating glaciers, along the coast of 
Long Island and to the north and east.
    Primary productivity is highest in the nearshore and estuarine 
regions, with coastal phytoplankton blooms initiating in the winter and 
summer, although the timing and spatial extent of blooms varies from 
year to year. The relatively productive continental shelf supports a 
wide variety of fauna and flora, making it important habitat for 
various benthic and fish species and marine mammals, including but not 
limited to, fin whales, humpback whales, North Atlantic right whales, 
and other large whales as they migrate through the area. The Cold Pool, 
a bottom-trapped cold, nutrient-rich pool and distinct oceanographic 
feature of the Mid-Atlantic Bight, creates habitat that provides 
thermal refuge to cold water species in the area (Lentz, 2017). Cold 
Pool waters, when upwelled to the surface, promote primary productivity 
within this region (Voynova et al., 2013).
    The seafloor in the Project Area is dynamic and changes over time 
due to current, tidal flows, and wave conditions. As the Lease Area is 
located just south of the mouth of Delaware Bay, the seafloor bedforms 
and sediments are affected by interactions between storm-driven 
currents, storm discharges from Delaware Bay, and tidal flows 
associated with Delaware Bay (US Wind, 2023b). The Lease Area is 
defined by medium-coarse grained sand at the surface and sub-surface 
interlays of clay and gravel (Alpine, 2015). The most prominent 
bathymetric features of the Lease Area are ridges and swales offshore 
of the Delmarva Peninsula that extend seaward from Delaware Bay (US 
Wind, 2023b). Sand ripples are present throughout the Project area. 
Sediment within the onshore export cable corridor is composed of 
predominantly silt-sand mixed with medium-coarse grained sand (US Wind, 
2023b). The bottom habitat of Indian River Bay, through which the 
export cable route may pass through, is relatively flat in elevation 
and comprises fine to course-grained sands area.
    The benthic habitat of the Project Area contains a variety of 
seafloor substrates, physical features, and associated benthic 
organisms. The benthic macrofaunal community of the Lease Area is 
dominated by polychaetes and oligochaete worms yet may also include 
sand dollars, sea stars, tube anemones, hermit crabs, rock crabs, moon 
snails, nassa snails, surf clams, sea scallops, shrimp, and ocean 
quahog (Guida et al., 2017).
    Additional information on the underwater environment's physical 
resources can be found in the COP for the Maryland Offshore Wind 
Project (US Wind, 2023b) available at: https://www.boem.gov/renewable-energy/state-activities/maryland-offshore-wind-construction-and-
operations-plan.
    US Wind would construct the Project in Federal and State waters 
offshore of Maryland within the BOEM Lease Area OCS-A 0490 and 
associated export cable routes (figure 1). The Lease Area covers 
approximately 323.7 square kilometers (km\2\) (80,000 acres) and is 
located approximately 18.5 km offshore of Maryland. The water depths in 
the Lease Area range from 13 m along the western lease border to 41.5 m 
(43 to 136.1 feet (ft)) along the southeast corner of the lease area 
while depths along the export cable routes range from 10 m to 45 m (33 
to 148 ft). Mean sea

[[Page 509]]

surface temperatures range from 42 to 75.8 degrees Fahrenheit ([deg]F; 
5.56 to 24.3 degrees Celsius ([deg]C), while the depth-average annual 
water temperature is 58.2 [deg]F (14.6 [deg]C). Cables would come 
ashore at 3Rs Beach or Tower Road within Delaware Seashore State Park. 
The Project Area is defined as the Lease Area and export cable route 
area.
BILLING CODE 3510-22-P
[GRAPHIC] [TIFF OMITTED] TP04JA24.000

BILLING CODE 3510-22-C

Detailed Description of the Specified Activity

    Below, we provide detailed descriptions of US Wind's planned 
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, OSS, and Met Tower Foundations
    US Wind proposes to install up to 114 WTGs on monopile foundations, 
4 OSSs on 3-m pin pile jacket foundations, and one Met tower on a 1.8-m 
pin pile foundation. US Wind is also considering monopile foundations 
and suction bucket jacket foundations for OSSs, although 3-m pin pile 
jacket foundations are the most likely foundation type. All WTG and OSS 
foundations would be installed between May 1 and November 30 in 2025 
(MarWin), 2026 (Momentum Wind), and 2027 (Future Development) (refer 
back to table 1). No pile driving would occur December 1-April 30. For 
purposes of this proposed rule, US Wind assumed all foundations would 
be installed using an impact hammer, unless US Wind

[[Page 510]]

uses gravity suction bucket-based jacket foundations for OSSs.
    A WTG monopile foundation typically consists of a coated single 
steel tubular section, with several sections of rolled steel plate 
welded together. Each monopile would have a maximum diameter of 11 m 
(36 ft). WTGs would be spaced approximately 0.77 nautical miles (nmi; 
1.42 km) in an east-west direction and 1.02 nmi (1.89 km) in a north-
south direction and driven to a maximum penetration depth of 50 m (164 
ft) below the seafloor (US Wind, 2023a). Monopile foundations would 
consist of a monopile with an integrated or separate transition piece. 
US Wind would install rock scour protection around the base of the 
monopile foundations prior to or following installation to minimize 
scour around the foundation bases (US Wind, 2023). Monopile foundations 
would be installed using an MHU 4400 impact hammer at a maximum hammer 
energy of 4,400 kJ. US Wind anticipates that one monopile will be 
installed per day at a rate of approximately 2 hours of active pile 
driving time per monopile, though two or more monopile installations 
per day may be possible depending on operational limitations and 
environmental conditions (table 3).
    Monopile, pin pile jacket, and gravity suction-bucket jacket 
foundations are technically and economically feasible for OSSs. Up to 
four OSSs would be installed via impact pile driving (monopile and pin 
pile jacket foundations) or dewatering process to sink suction buckets 
to the appropriate depth. Rock scour protection would be applied after 
foundation installation.
    Monopile foundations for the OSSs would have a maximum diameter of 
11 m (36 ft) and maximum pile penetration depth of 40 m (131 ft). 
Monopile foundations would have a separate transition piece with a 
number of J-tubes to support and protect cables as well as to connect 
the inter-array cables and the offshore export cable to the OSS. If 
monopiles are selected for the OSSs, monopiles would be installed 
through impact pile driving according to the same methods as described 
for WTG monopile foundations.
    Jacket foundations with pin piles, if selected for OSS design, may 
be pre-piled or post-piled using pin piles with a maximum diameter of 
3-m (9.8 ft). A pre-piled jacket would involve pin piles pre-installed 
in the seabed using a template. A post-piled jacket foundation is 
formed by a steel lattice construction (comprising tubular steel 
members and welded joints) secured to the seabed by means of hollow 
steel pin piles attached to the jacket where the pin piles have been 
driven through jacket skirts (skirt piles). Each jacket structure may 
have three, four, or six legs. A four-leg OSS with a post-piled pin 
pile jacket foundation is the most likely design and was selected for 
modeling impacts to marine mammals from OSS installation. Each jacket 
foundation would consist of up to four pin piles. In total, US Wind 
would install up to 4 OSSs for a total of 16 pin piles. Up to four 3-m 
pin piles would be installed per day using an impact hammer with a 
maximum hammer energy 1,500 kJ (table 3). Pin piles would have a 
maximum diameter of 3 m (9.8 ft) each and would be installed 
vertically.
    US Wind plans to install one Met tower to serve as a permanent 
metocean monitoring station. The Met tower foundation would be a Braced 
Caisson design, in which one main steel pile would be supported 
laterally by two steel supporting (bracing) piles. The main steel pin 
pile would have a maximum diameter of 1.8 m (72 in) and the two bracing 
pin piles would have a maximum diameter of 1.5 m (60 in). US Wind 
assumed bracing pin piles would be 1.8 m in diameter for the purposes 
of modeling impacts of installation on marine mammals. The main caisson 
and bracing piles would be installed using an impact hammer with a 
maximum energy of 500 kJ at a rate of approximately 2 hours per pin 
over the course of 2 days (table 3). The Met tower would include 
measurement devices to record weather conditions, such as wind and 
waves, in the Project Area. US Wind identified three potential 
locations for placement of the Met tower along the southern edge of the 
Lease Area, as shown in figure 1-2 of the ITA application.
    If US Wind installs suction bucket jacket foundations, they would 
have a maximum diameter of 15 m (49 ft) and pile penetration depth of 
15 m (49 ft). Suction bucket jacket foundations would be installed 
through a dewatering process which generates pressure that draws the 
buckets to the desired depth. The process to install a suction bucket 
foundation does not produce elevated noise levels that could harass 
marine mammals; therefore, no take from this activity is anticipated to 
occur or is proposed to be authorized. Installation is not expected to 
result in take of marine mammals. Suction bucket foundations are not 
further discussed.

                                      Table 3--Impact Pile Driving Schedule
----------------------------------------------------------------------------------------------------------------
                                                                           Piling time  Piling time
                                    Project      Max  hammer   Number of     duration     duration      Number
          Pile type                component        energy       hammer      per pile     per day     piles/day
                                                   (kJ) \1\      blows        (min)        (min)
----------------------------------------------------------------------------------------------------------------
11-m monopile................  WTG.............        1,100          600          120          120            1
                                                       2,200        2,400
                                                       3,300    \2\ 1,800
3-m pin pile jacket            OSS.............        1,500       19,200          120          480            4
 foundations.
1.8-m Steel Bracing Caisson    Met tower.......          500        2,988          120          360            1
 pile \3\.
1.8-m Steel Bracing pile \3\.                                                                                  2
----------------------------------------------------------------------------------------------------------------
\1\ Assumes MHU 4400 hammer.
\2\ US Wind has proposed a hammer strike energy progression for impact pile driving of monopiles, beginning at a
  hammer energy of 1,100 kJ to an energy of 3,300 kJ, although the maximum hammer energy possible (4,400 kJ) was
  used and scaled in the modeling.
\3\ A bracing caisson design has one main pile supported laterally by two bracing piles. The bracing caisson
  pile and bracing piles for the Met tower are pin piles.

    While pre-piling preparatory work and post-piling activities could 
be ongoing at one foundation position as pile driving is occurring at 
another position, no concurrent/simultaneous pile driving of 
foundations would occur (see Dates and Duration section). Installation 
of foundations is anticipated to result in the take of marine mammals 
due to noise generated during pile driving. Proposed mitigation, 
monitoring, and reporting measures for impact pile driving are 
described in detail later in this document (see Proposed Mitigation and 
Proposed Monitoring and Reporting).
    US Wind anticipates the 21 WTGs to be installed during the MarWin 
campaign would become operational by December 31, 2025. The 55 WTGs to 
be installed during the Momentum Wind

[[Page 511]]

campaign would become operational by December 31, 2026, and the 38 WTGs 
to be installed during the Future Development campaign would become 
operational by December 31, 2027 (table 2).
HRG Surveys
    US Wind plans on conducting HRG surveys to identify any seabed 
debris or unexploded ordnance (UXO), confirm previously surveyed site 
conditions prior to cable installation, meet BOEM or other agency 
requirements for additional surveys, and to refine or (microsite) 
locations of construction footprints, WTG and OSS foundations, and 
cables. US Wind has committed to not detonating any UXOs. US Wind would 
prepare an avoidance plan for working around UXOs and conduct micro-
siting surveys to identify any UXOs in the area. Only the micro-siting 
surveys have the potential to result in harassment of marine mammals 
and would be limited to the Lease Area. Pre-construction and UXO HRG 
surveys would utilize equipment that have operating frequencies that 
are above relevant marine mammal hearing thresholds or no acoustic 
output (e.g., magnetometers). Take is not anticipated from the use of 
this equipment; therefore, pre-construction and UXO HRG surveys are not 
analyzed further.
    HRG micro-siting surveys would occur within the Lease Area, 
focusing on the inter-array cable layout, as well as along the offshore 
export cable corridors, if necessary. US Wind estimates approximately 
14 days of HRG micro-siting survey effort per year from April through 
June during years 2 and 3 (Momentum Wind in 2026, Future Development in 
2027) and only during daylight hours. HRG micro-siting surveys would be 
conducted using one vessel at a time. Up to 111.1 km of survey lines 
would be surveyed per vessel each survey day at approximately 7.4 km/
hour (4 knots (kn)) during daylight hours. Acoustic equipment described 
above (multibeam echosounders, side scan sonars, and marine 
magnetometers) may be used during micro-siting surveys as well as non-
impulsive ultra-short baseline positioning equipment (i.e., Ultra-Short 
BaseLine (USBL) and other parametric sub-bottom profilers), shallow 
penetration sub-bottom profilers (SBPs) (e.g., Innomar SES-2000 non-
parametric SBP), and medium penetration SBPs (e.g., sparkers and 
boomers). Take is not anticipated resulting from the use of ultra-short 
baseline position equipment or the Innomar SBP as these equipment types 
have a very narrow beam width which limits acoustic propagation, and 
these sources are not analyzed further.
    Of the HRG equipment types proposed for use during micro-siting 
surveys, the following sources have the potential to result in take of 
marine mammals:
    <bullet> Medium penetration SBPs (boomers) to map deeper subsurface 
stratigraphy as needed. A boomer is a broad-band sound source operating 
in the 0.2 kHz to 15 kHz frequency range. This system is typically 
mounted on a sled and towed behind the vessel.
    <bullet> Medium penetration SBPs (sparkers) to map deeper 
subsurface stratigraphy as needed. A sparker creates acoustic pulses 
from 0.05 kHz to 3 kHz omni-directionally from the source that can 
penetrate several hundred meters into the seafloor. These are typically 
towed behind the vessel with adjacent hydrophone arrays to receive the 
return signals.
    Table 4 provides a list of the equipment specifications for the 
medium penetration SBPs that may result in take of marine mammals 
during HRG micro-siting surveys. Equipment with operating frequencies 
above 180 kHz are not discussed further because they are outside the 
general hearing range of marine mammals and therefore do not have the 
potential to cause harassment. Although US Wind has proposed a 
beamwidth of 100 degrees for the Geo Spark sparker, NMFS has determined 
that a 180-degree beamwidth is more appropriate for this analysis, as 
sparkers are considered omnidirectional sources (Ruppel et al., 2022). 
Additionally, US Wind proposed an RMS source level of 219 decibels 
(dB), based on a manufacturer specification. Because it was not clear 
which operating energy, tip configuration, or specific sparker model 
this source level was based on, and also because the manufacturer-
provided source levels are not well-documented, NMFS considers the 
well-documented measurements for a wide variety of sparker 
configurations from Crocker and Fratantonio (2016) to be the best-
available data for use in deriving appropriate proxy source levels. 
Further, the RMS source levels are given directly in Crocker and 
Fratantonio (2016), thus mitigating uncertainty associated with 
deriving RMS levels from peak levels. For these reasons, we have 
instead used an RMS source level of 206 dB, based on Crocker and 
Fratantonio (2016) and a 3 dB adjustment to account for the potential 
use of two 400 tip decks. Source characteristics and details of the 
source proxy are found in Table 4, and its footnotes below. The net 
result of NMFS's changes to the proposed methodology is an increase of 
the Level B isopleth from 50.1 m to 200 m.
    Proposed mitigation, monitoring, and reporting measures for HRG 
micro-siting surveys are described in detail later in this document 
(see Proposed Mitigation and Proposed Monitoring and Reporting).

                   Table 4--Summary of Representative HRG Micro-Siting Survey Equipment That May Result in Take of Marine Mammals \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Operating   Peak  source   RMS source      Pulse
               HRG system                    Representative  survey     frequencies      level        level       duration     Repetition     Beamwidth
                                                   equipment               (kHz)       (dBpeak)      (dBRMS)        (ms)       rate  (Hz)     (degrees)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Medium- penetration SBP.................  Applied Acoustic S Boomer           0.1-5           211          205           0.6             3            80
                                           \2\.
                                          AA Dura Spark 400 tip (500          0.3-4           214          206           2.3             2           180
                                           J) \3\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
dB = decibels; Hz = hertz.
\1\ Of note, NMFS has performed a preliminary review of a report submitted by Rand (2023), that includes measurements of the Geo-Marine Geo-Source 400
  sparker (400 tip, 800 J), and suggests that NMFS is assuming lower source and received levels than appropriate in its assessments of HRG impacts. NMFS
  has determined that the values in our assessment remain appropriate, based on the model methodology (i.e., source level propagated using spherical
  spreading) here predicting a peak level 3 dB louder than the maximum measured peak levels at the closest measurement range in Rand (2023). NMFS will
  continue reviewing any available data relevant to these sources.
\2\ Crocker and Fratantonio (2016) provide Applied Acoustics S Boomer measurements. Frequency and repetition rate of the Applied Acoustics S Boomer
  verified by survey contractors.
\3\ AA Dura-Spark 400 tip used as a proxy due to similar configuration and energy to the Geo-spark 2000. See Table 10 in Crocker and Fratantonio (2016)
  source levels for 500 J setting and 400 tips. Based on previous survey experience, US Wind expects to operate the Geo-spark at 400-500 J per 400 tip
  deck, with the possibility of one or two total 400 tip decks (i.e., 400-1000 J total energy). To account for the potential of two decks, the source
  level is doubled in energy, which results in the addition of approximately 3 dB (to the 206 dB RMS, as shown in Table 4).


[[Page 512]]

Cable Landfall Construction
    US Wind would bring up to four offshore export cables through 
Indian River Bay to shore to landing locations at 3Rs Beach or Tower 
Road within the Delaware Seashore State Park (figure 1). The US Wind 
export cable would be connected to the onshore transmission cable at 
the landfall locations using horizontal directional drilling (HDD) and 
a jet plow. Cables would be pulled into cable ducts that would route 
the cables under the beach to subterranean transition vaults, located 
in existing developed areas such as parking lots. US Wind evaluated 
cofferdams at the HDD locations and determined that the use of a 
gravity cell would be more appropriate for soil conditions as well as 
avoid the use of a vibratory hammer that would create additional 
underwater sound. The gravity cell would be lowered onto the seafloor 
and would not require the walls of the cell to be driven into the 
seabed (i.e., no pile driving would occur). The HDD drill rig would be 
set up onshore in an excavated area and the drill would advance to the 
offshore exit point. The offshore cable would be pulled in through the 
HDD ducts into the cable jointing/transition vault at the landfall 
location. The cable installation vessel would then begin laying the 
cable on the seabed as described in the Cable Laying and Installation 
section below. Given the work is not expected to produce noise levels 
that could result in harassment to marine mammals, HDD and gravity cell 
installation is not expected to result in the take of marine mammals. 
US Wind did not request, and NMFS is not proposing to authorize, take 
associated with cable landfall construction; therefore, this activity 
is not discussed further.
Cable Laying and Installation
    Cable burial operations would occur both in the Lease Area and ECCs 
from the Lease Area to shore. The inter-array cables would connect the 
WTGs to any one of the OSSs. All WTGs would connect to an OSS in 
strings of 4-6 WTGs via the inter-array cables. Cables within the ECCs 
would carry power from the OSSs to shore at the landfall location(s) 
within Delaware Seashore State Park. The offshore export cables would 
be buried in the seabed at a target depth of up to 1 m (3.3 ft) to 3 m 
(9.8 ft), although the exact depth would not exceed 4 m (13.1 ft). 
Inter-array cable burial operations would be installed to a target 
depth of 1 m (3.3 ft) to 2 m (6.6 ft), not to exceed 4 m (13.1 ft) in 
depth and would follow installation of the WTG and OSS foundations as 
the foundations must be in place to provide connection points. Offshore 
cable installation may occur concurrently with foundation installation.
    Cable laying, cable installation, and cable burial activities 
planned to occur during the construction of the Project would include 
the following methods: offshore export cable pull through the HDD duct, 
simultaneous lay and burial for cable installation through the use of a 
jet plow, and post-lay burial for cables, as needed. Offshore export 
cables would be pulled through the HDD duct, as described in the Cable 
Landfall Construction section above. The inter-array cables would be 
installed from a dynamically positioned cable installation vessel. US 
Wind plans to use a jet plow to achieve the target inter-array and 
offshore cable burial depth. If necessary, post-lay cable burial would 
be completed through the use of a cable installation support vessel and 
remotely operated vehicle (ROV) system (US Wind, Inc., 2023a). Areas 
with cable crossings or hard bottoms may require additional protection 
measures, such as mattresses, rock placement, or cable protection 
systems. In shallow areas of cable installation, dredging may be 
necessary to allow access by the cable lay barge. As the noise levels 
generated from cable laying and installation work are low, the 
potential for take of marine mammals to result is discountable. US Wind 
is not requesting, and NMFS is not proposing, to authorize take 
associated with cable laying activities. Therefore, cable laying 
activities are not analyzed further in this document.
Site Preparation and Scour Protection
    Site preparation typically includes sand bedform leveling, boulder 
clearance, pre-lay grapnel runs, and a pre-lay survey to prepare the 
area for export cable installation. Route clearance activities would be 
conducted prior to offshore export cable installation. Project 
activities would include a pre-installation survey and grapnel run 
along the offshore export cable corridor to remove debris that could 
impact the cable lay and burial. US Wind does not expect pre-
installation seabed preparation, such as leveling, pre-trenching, to be 
necessary. A pre-lay grapnel run would be conducted along the cable 
route to remove debris that could impact cable lay and burial.
    US Wind would also deposit rock around each foundation as scour 
protection. Prior to or following the installation of a monopile or 
jacket foundation for the OSS, a first layer of scour protection rocks 
will be deployed in a circle around the pile location to stabilize the 
seabed (US Wind, Inc., 2023a). If suction bucket foundations are 
selected for OSSs, scour protection would be deployed after buckets 
reach target penetration depth. A 1-2 m (2-7 ft) thick second layer of 
larger rocks would be placed for stabilization once the inter-array 
cables have been pulled into the monopile. Scour protection may also be 
applied as additional protection for cables after burial.
    NMFS does not expect scour protection placement or site preparation 
work, including pre-lay grapnel runs and pre-lay surveys, to generate 
noise levels that would cause take of marine mammals. Although not 
anticipated, any necessary dredging, bedform leveling, or boulder 
clearance would be extremely localized at any given time, and NMFS 
expects that any marine mammals would not be exposed at levels or 
durations likely to disrupt behavioral patterns (i.e., migrating, 
foraging, calving, etc.). Therefore, the potential for the take of 
marine mammals to result from these activities is so low as to be 
discountable. US Wind did not request, and NMFS is not proposing, to 
authorize any takes associated with site preparation and scour 
protection activities; therefore, they are not analyzed further in this 
document.
Vessel Operation
    US Wind will utilize various types of vessels over the course of 
the 5-year proposed regulations for surveying, foundation installation, 
cable installation, WTG and OSS installation, and support activities. 
US Wind has identified several existing port facilities located in 
Maryland, Virginia, Delaware, and New Jersey to support offshore 
construction, assembly and fabrication, crew transfer and logistics, 
and other operational activities. In addition, some components, 
materials, and vessels could come from Canadian and European ports. A 
variety of vessels would be used throughout the construction 
activities. These range from crew transportation vessels, tugboats, 
jack-up vessels, cargo ships, and various support vessels (table 5). 
Details on the vessels, related work, operational speeds, and general 
trip behavior can be found in table 1-2 of the ITA application and 
table 4-1 in the COP volume 1.
    As part of various vessel-based construction activities, including 
cable laying and construction material delivery, dynamic positioning 
thrusters may be utilized to hold vessels in position or move slowly. 
Sound produced through use of dynamic positioning thrusters is similar 
to that

[[Page 513]]

produced by transiting vessels, and dynamic positioning thrusters are 
typically operated either in a similarly predictable manner or used for 
short durations around stationary activities. Fall pipe vessels may use 
dynamic positioning thrusters during the installation of scour 
protection up to 24 hours per day. Jack-up cranes or floating cranes 
may use dynamic positioning thrusters for up to 4 hours per WTG or OSS 
installation. Heavy lift and general cargo vessels may use dynamic 
positioning thrusters for the delivery of Project components from the 
manufacturing location to the staging/assembly port only while 
maneuvering in port. Multipurpose offshore supply vessels may also use 
dynamic positioning thrusters throughout the day during the pre-lay 
grapnel run boulder clearance and cable burial. Jack-up or 
accommodation vessels may use dynamic positioning thrusters while 
constructing housing for offshore works, yet only while maneuvering to 
the site, which would last approximately 2 hours per WTG or OSS. 
Dynamic positioning thrusters may also be used by vessels throughout 
the day for pre-installation, geophysical and geotechnical verification 
surveys, cable installation, placement of scour protection and concrete 
mattresses, seabed preparation and leveling, and commissioning 
activities. Sound produced by dynamic positioning thrusters would be 
preceded by, and associated with, sound from ongoing vessel noise and 
would be similar in nature; thus, any marine mammals in the vicinity of 
the activity would be aware of the vessel's presence. Construction-
related vessel activity, including the use of dynamic positioning 
thrusters, is not expected to result in take of marine mammals. US Wind 
did not request, and NMFS does not propose to authorize, any take 
associated with vessel activity.
    The total vessels expected for use during the Project are provided 
in table 5; more details can be found in table 1-2 of the ITA 
application. Assuming the maximum design scenario, approximately 458 
total vessel round trips are expected to occur during the MarWin 
construction campaign (2025), approximately 1,944 total vessel round 
trips are expected to occur during the Momentum Wind construction 
campaign (2026), and approximately 1,587 total vessel round trips are 
expected to occur during the Future Development construction campaign 
(2027). Vessels would remain on site during construction activities 
each year to reduce the number of transits between the Project Area and 
ports.
    For operations and maintenance, US Wind anticipates that up to 10 
vessels could be used, although not all vessels would operate at the 
same time or every year. A fall pipe vessel, jack-up vessel, and multi-
role survey vessel only be used for non-routine maintenance activities 
(table 5). Crew transfer vessels would not be likely to operate on a 
daily basis year-round, however, to be conservative, US Wind assumed 
that these vessels would operate on a daily basis (table 5).

               Table 5--Type and Number of Vessels Anticipated During Construction and Operations
----------------------------------------------------------------------------------------------------------------
                                                                                                     Expected
                                                                                  Max number  of      maximum
                Project period                            Vessel types                vessels     annual  number
                                                                                                    of trips \1\
----------------------------------------------------------------------------------------------------------------
Foundation Installation.......................  Transport, Installation, and                   5              10
                                                 Support.
                                                Crew Transfer...................               1              26
                                                Environmental Monitoring and                   4              52
                                                 Mitigation.
WTG Installation..............................  Transport, Installation, and                   4              26
                                                 Support.
                                                Crew Transfer Vessel............               0               0
Inter-array Cable Installation................  Transport, Installation, and                   4               5
                                                 Support.
                                                Crew Transfer Vessel............               2             136
OSS Installation..............................  Transport, Installation, and                   9              16
                                                 Support.
                                                Crew Transfer Vessel............               0               0
Offshore Export Cable Installation............  Transport, Installation, and                   6              25
                                                 Support.
                                                Crew Transfer Vessel............               0               0
Operations and Maintenance \2\................  Fall Pipe Vessel................               1               1
                                                Crew Transfer Vessel (refueling)               1              20
                                                 \3\.
                                                Jack-up Vessel..................               1               1
                                                Multi-role Survey Vessel \4\....               2              13
                                                Sportfisher Vessel..............               1             100
                                                Crew Transfer Vessel............               4         365 \5\
----------------------------------------------------------------------------------------------------------------
\1\ Vessels and trips provided represent the maximum number of year 2 trips for each vessel category for each
  activity from US Wind's OCS air permit application, appendix A.
\2\ Potential operation and maintenance ports include Ocean City, MD; Baltimore, MD; and Portsmouth, VA.
\3\ Only for non-routine maintenance activities
\4\ One of these vessels would be for non-routine maintenance activities
\5\ Expected maximum annual number of trips per year for each of the four vessels. Fourth vessel may not be
  necessary.

    While a vessel strike could cause injury or mortality of a marine 
mammal, NMFS is proposing to require extensive vessel strike avoidance 
measures that would avoid vessel strikes from occurring (see Proposed 
Mitigation section). US Wind has not requested, and NMFS is not 
proposing to authorize, take from vessel strikes.
Fisheries and Benthic Monitoring
    Fisheries and benthic monitoring surveys are being designed for the 
project in collaboration with UMCES. UMCES and US Wind would conduct 
pot surveys and recreational fishing surveys focusing on evaluating the 
extent that commercial and recreational fisheries would be impacted due 
to changes in black sea bass aggregation behaviors during and after 
Project construction activities. The program includes a trial baseline 
year to test deployments and collect baseline data in the Project Area 
as well as a data synthesis year before construction activities would 
begin. UMCES and US Wind would conduct additional passive acoustic 
monitoring research for marine mammals.

[[Page 514]]

    Pot surveys offshore Ocean City would be conducted monthly from 
March through November using ropeless fishing gear to collect data on 
black sea bass relative abundance in the vicinity of the proposed 
turbine areas. Catches and sizes of other fauna would be assessed as 
well. US Wind would set strings of 15 pots (six strings, up to 90 pots 
total) from a commercial fishing vessel, each string with a 1-day 
duration set period. EdgeTech ropeless gear (EdgeTech, 2023) would 
allow sets (trawls) of 15 pots without any rope in the water column. 
Approximately 300-355 m (984-1,165 ft) of \7/16\ inch (in) main-line 
rope would lie on the bottom during the survey. There would also be 
approximately 1.5 m of \7/16\ in line that would form the bridle 
connecting each pot to the main line. Each string of pots would consist 
of 15 black sea bass pots, an EdgeTech pot, and an anchor. The EdgeTech 
pot would be the release pot attached at the end of each trawl. Each 
survey would consist of six strings deployed for a 1-day soak time (see 
diagram in Proposed Rule Comment Responses Memo, October 12, 2023). 
After the 1-day set period, UMCES and US Wind would retrieve the pot 
trawls by sending a release command from the on-site research vessel to 
activate an acoustic release on the release pot. Upon activation, the 
flotation with the attached rope would ascend to the water surface. 
UMCES and US Wind would recover the floatation connected to the release 
pot as well as the rest of the pots for that trawl. The pot survey 
would be conducted under a NMFS Scientific LOA for black sea bass 
collection research, of which a similar letter was received by UMCES 
from NMFS Greater Atlantic Regional Fisheries Office (GARFO) for the 
initial trial baseline year.
    UMCES and US Wind would operate the recreational fishing survey off 
a recreational charter vessel based in Ocean City to compare data on 
black sea bass and other fauna between two artificial reef/wreck sites 
and two turbine sites using a Before-After-Control-Impact (BACI) study 
design. Angling techniques, such as drop bottom fishing and jigging, 
would be used to collect catch data on black sea bass and other fauna. 
Six monthly recreational surveys spanning a 2-day window each, would be 
conducted annually from May through October.
    Passive acoustic monitoring research would focus on using 
rockhopper recorders to determine occurrence and position of large 
whales and dolphins as well as F-POD (full waveform capture Pod) 
devices to detect tonal echolocation clicks of small cetaceans in the 
Lease Area. The goal of the research would be to distinguish changes in 
marine mammal behavior due to natural inter-annual variation versus 
behaviors influenced by wind facility operations. US Wind and UMCES 
would use a before-during-after gradient design involving 2 years of 
monitoring in each period before, during, and after Project 
construction, from 2023 to 2029. The Rockhopper recorder would sample 
at 200 kHz for baleen whales and dolphins while the F-POD would detect 
echolocation clicks of small cetaceans. Rockhopper recorders would 
include a localization array with the Lease Area to allow the positions 
of calling North Atlantic right whales, humpback whales, and dolphins 
to be detected. Innovasea receivers would also be attached at up to 
four mooring sites within the Lease Area to examine spatiotemporal 
patterns of previously tagged fish, such as Atlantic sturgeon, white 
sharks, and sand tiger sharks.
    Given the gear used (ropeless pot and hook and line), the fishery 
surveys present little risk to marine mammals (although some hook and 
line entanglement has been documented in marine mammals). To further 
minimize this already low risk of interaction, US Wind has proposed, 
and NMFS has included in the proposed rule, mitigation and monitoring 
measures to avoid taking marine mammals, including, but not limited to, 
monitoring for marine mammals before and during fishing/survey 
activities, not deploying, pulling gear, or fishing in certain 
circumstances, limiting tow times, and fully repairing nets and lines. 
All vessel captains and crew would also abide by the vessel strike 
avoidance measures outlined in Sec.  217.344(b) of this rule. A full 
description of mitigation measures can be found in the Proposed 
Mitigation section.
    With the implementation of these measures, US Wind does not 
anticipate, and NMFS is not proposing to authorize, take of marine 
mammals incidental to research pot and recreational surveys. Given no 
take is anticipated from these surveys, impacts from fishery surveys 
will not be discussed further in this document (with the exception of 
the description of measures in the Proposed Mitigation section).

Description of Marine Mammals in the Geographic Area

    Thirty-eight marine mammal species under NMFS' jurisdiction have 
geographic ranges within the western North Atlantic OCS (Hayes et al., 
2023). However, for reasons described below, US Wind has requested, and 
NMFS proposes to authorize, take of only 19 species (comprising 20 
stocks) of marine mammals. Sections 3 and 4 of US Wind's ITA 
application summarize available information regarding status and 
trends, distribution and habitat preferences, and behavior and life 
history of the potentially affected species. NMFS fully considered all 
of this information, and we refer the reader to these descriptions in 
the application instead of reprinting the information.
    Additional information regarding population trends and threats may 
be found in NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports) and more general information about 
these species (e.g., physical and behavioral descriptions) may be found 
on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Of the 38 marine mammal species and/or stocks with geographic 
ranges that include the Project Area (i.e., found in the coastal and 
offshore waters of Maryland), 19 species are not expected to be present 
or are considered rare or unexpected in the Project Area based on 
sighting and distribution data (see table 3-1 in US Wind's ITA 
application). Specifically, the following cetacean species are known to 
occur off of Maryland but are not expected to occur in the Project Area 
due to the location of preferred habitat outside the Lease Area and 
ECCs, based on the best available information, and therefore US Wind 
did not request, and NMFS is not proposing to authorize take, of these 
species: Blue whale (Balaenoptera musculus), Cuvier's beaked whale 
(Ziphius cavirostris), four species of Mesoplodont beaked whales 
(Mesoplodon densitostris, M. europaeus, M. mirus, and M. bidens), 
Atlantic white-sided dolphin (Lagenorhynchus acutus), Clymene dolphin 
(Stenella clymene), dwarf sperm whale (Kogia sima), false killer whale 
(Pseudorca crassidens), Fraser's dolphin (Lagenodelphis hosei), melon-
headed whale (Peponocephala electra), northern bottlenose whale 
(Hyperoodon ampullatus), pygmy killer whale (Feresa attenuata), pygmy 
sperm whale (Kogia breviceps), sperm whale (Physeter macrocephalus), 
spinner dolphin (Stenella longirostris), and white-beaked dolphin 
(Lagenorhynchus albirostris). Two species of phocid pinnipeds are also 
uncommon in the Project Area, including: harp seals (Pagophilus 
groenlandica) and hooded seals (Cystophora cristata). However, harp 
seals are known to strand in coastal Maryland. Therefore, NMFS is

[[Page 515]]

proposing to authorize take of harp seals.
    In addition, the Florida manatee (Trichechus manatus, a sub-species 
of the West Indian manatee) has been previously documented as an 
occasional visitor to the Mid-Atlantic region during summer months 
(Morgan et al., 2002; Cummings et al., 2014). However, manatees are 
managed by the U.S. Fish and Wildlife Service (USFWS) and are not 
considered further in this document.
    Table 6 lists all species or 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 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)). 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 or stocks and 
other threats. Take for 19 species (20 stocks) in table 6 is expected 
and proposed to be authorized for this activity.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock, 
or the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
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' U.S. Atlantic and Gulf of Mexico SARs. All values presented in 
table 6 are the most recent available at the time of publication and, 
unless noted otherwise, use NMFS' final 2022 SARs (Hayes et al., 2023) 
available online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports.

                              Table 6--Marine Mammal Species That May Occur in the Project Area and Be Taken, by Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/ MMPA status;   Stock abundance (CV,
           Common name \1\                Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
    North Atlantic right whale......  Eubalaena glacialis....  Western Atlantic.......  E, D, Y             338 (0; 332; 2020);           0.7   \6\ 31.2
                                                                                                             356 (346-363, 2022)
                                                                                                             \5\.
Family Balaenopteridae (rorquals):
    Fin whale.......................  Balaenoptera physalus..  Western North Atlantic.  E, D, Y             6,802 (0.24, 5573,             11        1.8
                                                                                                             2016).
    Sei whale.......................  Balaenoptera borealis..  Nova Scotia............  E, D, Y             6,292 (1.02, 3098,            6.2        0.8
                                                                                                             2016).
    Minke whale.....................  Balaenoptera             Canadian Eastern         -, -, N             21,968 (0.31, 17,002,         170       10.6
                                       acutorostrata.           Coastal.                                     2016).
    Humpback whale..................  Megaptera novaeangliae.  Gulf of Maine..........  -, -, Y             1,396 (0, 1,380, 2016)         22      12.15
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale \7\................  Orcinus orca...........  Western North Atlantic.  -, -, N             UNK (UNK, UNK, 2016)..        UNK          0
    Long-finned pilot whale.........  Globicephala melas.....  Western North Atlantic.  -, -, N             39,215 (0.3, 30,627,          306         29
                                                                                                             2016).
    Short-finned pilot whale........  Globicephala             Western North Atlantic.  -, -, Y             28,924 (0.24, 23,637,         236        136
                                       macrorhynchus.                                                        2016).
    Bottlenose dolphin..............  Tursiops truncatus.....  Western North Atlantic   -, -, N             62,851 (0.23, 51,914,         519         28
                                                                Offshore.                                    2016).
    Bottlenose dolphin..............  Tursiops truncatus.....  Northern Migratory       -, -, Y             6,639 (0.41, 4,759,            48  12.2-21.5
                                                                Coastal.                                     2016).
    Common dolphin..................  Delphinus delphis......  Western North Atlantic.  -, -, N             172,897 (0.21,              1,452        390
                                                                                                             145,216, 2016).
    Atlantic spotted dolphin........  Stenella frontalis.....  Western North Atlantic.  -, -, N             39,921 (0.27, 32,032,         320          0
                                                                                                             2016).
    Pantropical spotted dolphin.....  Stenella attenuata.....  Western North Atlantic.  -, D, N             6,593 (0.52, 4,367,            44          0
                                                                                                             2016).
    Risso's dolphin.................  Grampus griseus........  Western North Atlantic.  -, -, N             35,215 (0.19, 30,051,         301         34
                                                                                                             2016).
    Rough-toothed dolphin \7\.......  Steno bredanensis......  Western North Atlantic.  -, -, N             136 (1, 67, 2016).....        0.7          0
    Striped dolphin \7\.............  Stenella coeruleoalba..  Western North Atlantic.  -, -, N             67,036 (0.29, 52,939,         529          0
                                                                                                             2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of     -, -, N             95,543 (0.31, 74,034,         851        164
                                                                Fundy.                                       2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Western North Atlantic.  -, -, N             61,336 (0.08, 57,637,       1,729        339
                                                                                                             2018).
    Gray seal \8\...................  Halichoerus grypus.....  Western North Atlantic.  -, -, N             27,300 (0.22, 22,785,       1,389       4453
                                                                                                             2016).
    Harp seal.......................  Pagophilus               Western North Atlantic.  -, -, N             7.6M (UNK, 7.1M, 2019)    426,000    178,573
                                       groenlandicus.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).

[[Page 516]]

 
\2\ 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.
\3\ NMFS 2022 marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is the coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike).
\5\ The current SAR includes an estimated population (Nbest 338) based on sighting history through November 2020 (Hayes et al., 2023). In October 2023,
  NMFS released a technical report identifying that the North Atlantic right whale population size based on sighting history through 2022 was 356
  whales, with a 95 percent credible interval ranging from 346 to 363 (Linden, 2023).
\6\ Total annual average observed North Atlantic right whale mortality during the period 2016-2020 was 8.1 animals and annual average observed fishery
  mortality was 5.7 animals. Numbers presented in this table (31.2 total mortality and 22 fishery mortality) are 2015-2019 estimated annual means,
  accounting for undetected mortality and serious injury.
\7\ US Wind did not request take of these species; however, their exposure analysis demonstrates there is a low risk of harassment. Although these
  species are rare in the project area, NMFS is proposing to authorize a small amount of Level B harassment in the case of potential presence during
  pile driving.
\8\ 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.

    As indicated above, all 19 species and 20 stocks in table 6 
temporally and spatially co-occur with the activity to the degree that 
take is reasonably likely to occur. Three of the marine mammal species 
for which take is requested are listed as endangered under the ESA, 
including North Atlantic right, fin, and sei whales. In addition to 
what is included in sections 3 and 4 of US Wind's ITA application 
(https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-wind-inc-construction-and-operation-maryland-offshore-wind), the 
SARs (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments), and NMFS' website (https://www.fisheries.noaa.gov/species-directory/marine-mammals), we provide 
further detail below informing the baseline for select species (e.g., 
information regarding current UME and known important habitat areas, 
such as Biologically Important Areas (BIAs; https://oceannoise.noaa.gov/biologically-important-areas) (Van Parijs, 2015)). 
There are no ESA-designated critical habitats for any species within 
the project area (https://www.fisheries.noaa.gov/resource/map/national-esa-critical-habitat-mapper).
    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 July 2023, five UMEs are active. Four of these UMEs are occurring 
along the U.S. Atlantic coast for various marine mammal species. Of 
these, the most relevant to the project area are the North Atlantic 
right whale, humpback whale, and harbor and gray seal UMEs given the 
prevalence of these species in the project area. More information on 
UMEs, including all active, closed, or pending, can be found on NMFS' 
website at https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events.
    Below, we include information for a subset of the species that 
presently have an active or recently closed UME occurring along the 
Atlantic coast or for which there is information available related to 
areas of biological significance. For the majority of species 
potentially present in the specific geographic region, NMFS has 
designated only a single generic stock (e.g., ``western North 
Atlantic'') for management purposes. This includes the ``Canadian east 
coast'' stock of minke whales, which includes all minke whales found in 
U.S. waters and is also a generic stock for management purposes. For 
humpback and sei whales, NMFS defines stocks on the basis of feeding 
locations (i.e., Gulf of Maine and Nova Scotia, respectively). However, 
references to humpback whales and sei whales in this document refer to 
any individuals of the species that are found in the project area. Any 
areas of known biological importance (including the BIAs identified in 
LaBrecque et al., 2015) that overlap spatially (or are adjacent) with 
the project area are addressed in the species sections below.

North Atlantic Right Whale

    The North Atlantic right whale has been listed as Endangered since 
the ESA's enactment in 1973. The species was recently uplisted from 
Endangered to Critically Endangered on the International Union for 
Conservation of Nature (IUCN) Red List of Threatened Species (Cooke, 
2020). The uplisting was due to a decrease in population size (Pace et 
al., 2017), an increase in vessel strikes and entanglements in fixed 
fishing gear (Daoust et al., 2017; Davis & Brillant, 2019; Knowlton et 
al., 2012; Knowlton et al., 2022; Moore et al., 2021; Sharp et al., 
2019), and a decrease in birth rate (Pettis et al., 2022; Reed et al., 
2022). The western Atlantic stock is considered depleted under the MMPA 
(Hayes et al., 2023). There is a recovery plan (NMFS, 2005) for the 
North Atlantic right whale, and NMFS completed 5-year reviews of the 
species in 2012, 2017, and 2022 which concluded no change to the 
listing status is warranted.
    Designated by NMFS as a Species in the Spotlight, the North 
Atlantic right whale is considered among the species with the greatest 
risk of extinction in the near future (https://www.fisheries.noaa.gov/topic/endangered-species-conservation/species-in-the-spotlight).
    The North Atlantic right whale population had only a 2.8-percent 
recovery rate between 1990 and 2011 and an overall abundance decline of 
23.5 percent from 2011 to 2019 (Hayes et al., 2023). Since 2011, the 
North Atlantic right whale population has been in decline; however, the 
sharp decrease observed from 2015 to 2020 appears to have slowed, 
though the right whale population continues to experience annual 
mortalities above recovery thresholds (Pace et al., 2017; Pace et al., 
2021; Linden, 2023). North Atlantic right whale calving rates dropped 
from 2017 to 2020 with zero births recorded during the 2017-2018 
season. The 2020-2021 calving season had the first substantial calving 
increase in 5 years with 20 calves born (including 2 mortalities) 
followed by 15 calves during the 2021-2022 calving season and 12 births 
(including 1 mortality) in 2022-2023 calving season. These data 
demonstrate that birth rates are increasing. However, mortalities 
continue to outpace births. Best estimates indicate fewer than 70 
reproductively active females remain in the population and adult 
females experience a lower average survival rate than males (Linden, 
2023). In 2023, the total annual average observed North Atlantic right 
whale mortality increased from 8.1 (which represents 2016-2020) to 31.2 
(which represents 2015-2019), however, this updated estimate also 
accounts for undetected mortality and serious injury (Hayes et al., 
2023). Although the predicted number of deaths from the population are 
lower in recent years (2021-2022) when compared to the high number of 
deaths

[[Page 517]]

from 2014 to 2020 suggesting a short-term increase in survival, annual 
mortality rates still exceed PBR (Linden, 2023).
    Critical habitat for North Atlantic right whales is not present in 
the Project Area. However, the Project Area both spatially and 
temporally overlaps a portion of the migratory corridor BIA within 
which North Atlantic right whales migrate south to calving grounds 
generally in November and December, followed by a northward migration 
(primarily moms with young calves) into feeding areas far north of the 
Project Area in March and April (LaBrecque et al., 2015; Van Parijs, 
2015). North Atlantic right whale foraging may rarely opportunistically 
occur around the Project Area, yet the region is not considered primary 
foraging habitat. Engelhaupt et al. (2023) documented feeding and 
socializing behavior off Virginia and North Carolina, just south of the 
Project Area, suggesting that North Atlantic right whales may use the 
mid-Atlantic migratory corridor for more than just migration.
    NMFS' regulations at 50 CFR 224.105 designated Seasonal Management 
Areas (SMAs) for North Atlantic right whales in 2008 (73 FR 60173, 
October 10, 2008). SMAs were developed to reduce the threat of 
collisions between ships and North Atlantic right whales around their 
migratory route and calving grounds. The Delaware Bay SMA overlaps with 
the export cable corridor of the proposed project. This SMA is 
currently active from November 1 through April 30 of each year and may 
be used by North Atlantic right whales for migrating and/or feeding. As 
noted above, NMFS is proposing changes to the North Atlantic right 
whale speed rule (87 FR 46921, August 1, 2022). Due to the current 
status of North Atlantic right whales and the spatial proximity overlap 
of the proposed project with areas of biological significance, (i.e., a 
migratory corridor, SMA), the potential impacts of the proposed project 
on North Atlantic right whales warrant particular attention.
    During the spring, North Atlantic right whales use the migratory 
corridor BIA to move north from calving grounds off Georgia and Florida 
to feeding grounds in New England and Canadian waters (Hayes et al., 
2023). 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 over the same time period 
(Davis et al., 2020; Meyer-Gutbrod et al., 2022; Quintano-Rizzo et al., 
2021; O'Brien et al., 2022; Van Parijs et al., 2023) with reduced use 
of foraging habitats in the Great South Channel and Bay of Fundy and 
increased use of habitats within Cape Cod Bay and a region south of 
Martha's Vineyard and Nantucket Islands (Stone et al., 2017; Mayo et 
al., 2018; Ganley et al., 2019; Record et al., 2019; Meyer-Gutbrod et 
al., 2021; Van Parijs et al., 2023); these foraging habitats are all 
located several hundred kilometers north of the project area. 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. Observations of these transitions in right whale 
habitat use, variability in seasonal presence in identified core 
habitats, and utilization of habitat outside of previously focused 
survey effort prompted the formation of a NMFS' Expert Working Group, 
which identified current data collection efforts, data gaps, and 
provided recommendations for future survey and research efforts (Oleson 
et al., 2020). 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). 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).
    Although North Atlantic right whales move seasonally between 
foraging and calving grounds, Davis et al. (2017) acoustically detected 
right whales along the coast from Cape Hatteras, NC, United States to 
Nova Scotia, Canada year-round, suggesting that North Atlantic right 
whale use of the mid-Atlantic and southeast has increased since 2010 
(Davis et al., 2017). North Atlantic right whale presence in the 
Project Area is predominately seasonal with individuals likely to be 
transient and migrating through the area. Bailey et al. (2018) 
acoustically detected the year-round presence of North Atlantic right 
whales in the vicinity of the Project Area, with a maximum abundance 
during the late winter and early spring. In addition, a monitoring 
buoy, deployed by UMCES offshore of Ocean City Maryland in 2022, 
acoustically detected the presence of North Atlantic right whales in 
the lease area from November through January, with the highest 
frequency of confirmed detections occurring during the months of 
December and January (Woods Hole Oceanographic Institute, 2022). Visual 
surveys also confirm a maximum abundance of North Atlantic right whales 
in the vicinity of the Lease Area during the winter (Barco et al., 
2015; Williams et al., 2015). As part of the Mid-Atlantic Baseline 
Studies Project and Maryland Project, Williams et al. (2015) conducted 
standardized aerial and boat-based surveys of the Delaware, Maryland, 
Virginia Wind Energy Areas (WEAs), and visually observed North Atlantic 
right whales in the lease area during the months of February and March. 
Based upon year-round aerial surveys conducted from 2013 to 2015, Barco 
et al. (2015) observed the largest numbers of North Atlantic right 
whales in the Maryland WEA during the month of January, suggesting that 
the area may be a destination for non-breeding individuals and pulses 
of North Atlantic right whales may travel through the region. Barco et 
al. (2015) also documented North Atlantic right whale open mouth 
behavior, which is consistent with, though not necessarily indicative 
of, feeding. As part of the U.S. Navy's Marine Species Monitoring 
Program, HDR has conducted aerial and vessel-based surveys for large 
whales off Virginia and North Carolina since 2015. The majority of 
North Atlantic right whale sightings have occurred in these areas, just 
south of the Project Area, during the months of January-March 
(Aschettino et al., 2023). The highest density month for North Atlantic 
right whales in the vicinity of the lease area is February (0.00076 
individuals/km (0.54 nmi grid square)) (Roberts et al., 2023).
    Since 2017, 98 dead, seriously injured, or sublethally injured or 
ill North Atlantic right whales along the United States and Canadian 
coasts have been documented, necessitating a UME declaration and 
investigation. The leading category for the cause of death for this 
ongoing UME is ``human interaction,'' specifically from entanglements 
or vessel strikes. As of October 30, 2023, there have been 36 confirmed 
mortalities (dead, stranded, or floaters) and 34 seriously injured 
free-swimming whales for a total of 70 whales. Beginning on October 14, 
2022, the UME also considers animals with sublethal injury or illness 
bringing the total number of whales in the UME to

[[Page 518]]

115. Approximately 42 percent of the population is known to be in 
reduced health (Hamilton et al., 2021) likely contributing to smaller 
body sizes at maturation, making them more susceptible to threats and 
reducing fecundity (Moore et al., 2021; Reed et al., 2022; Stewart et 
al., 2022). More information about the North Atlantic right whale UME 
is available online at https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2023-north-atlantic-right-whale-unusual-mortality-event.

Humpback Whale

    Humpback whales were listed as endangered under the Endangered 
Species Conservation Act (ESCA) in June 1970. In 1973, the ESA replaced 
the ESCA, and humpbacks continued to be listed as endangered. On 
September 8, 2016, NMFS divided the once single species into 14 
distinct population segments (DPS), removed the species-level listing, 
and, in its place, listed 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 confidence interval 
(CI) 8,688-15,954) whales in 2004-2005, which is consistent with 
previous population estimates of approximately 10,000-11,000 whales 
(Stevick et al., 2003; Smith et al., 1999) and the increasing trend for 
the West Indies DPS (Bettridge et al., 2015).
    The Project Area does not overlap with any BIAs or other important 
areas for the humpback whales. A humpback whale feeding BIA extends 
throughout the Gulf of Maine, Stellwagen Bank, and Great South Channel 
from May through December, annually (LaBrecque et al., 2015). However, 
this BIA is located approximately 556.2 km (345.6 mi) north of the 
Project Area, and thus, would not be impacted by project activities.
    Humpback whale presence in the mid-Atlantic varies seasonally. 
Humpback whales are most typically observed in this region during the 
winter months (Williams et al., 2015d; Barco et al., 2015) and are 
known to be migratory off coastal Maryland, moving seasonally between 
northern feeding grounds in New England and southern calving grounds in 
the West Indies (Hayes et al., 2023). However, not all humpback whales 
migrate to the Caribbean during the winter as individuals are sighted 
in mid- to high-latitude areas during this season (Swingle et al., 
1993; Davis et al., 2020). In addition to a migratory pathway, the mid-
Atlantic region also represents a supplemental winter feeding ground 
for juveniles and mature whales (Barco et al., 2002). Records of 
humpback whales off the U.S. mid-Atlantic coast (New Jersey south to 
North Carolina) suggest that these waters are used as a winter feeding 
ground from December through March (Mallette et al., 2017; Barco et 
al., 2002; LaBrecque et al., 2015) and represent important habitat for 
juveniles, in particular (Swingle et al., 1993; Wiley et al., 1995).
    Acoustic monitoring in the vicinity of the lease area has detected 
the presence of humpback whales year-round, although detections exhibit 
similar seasonal trends as visual sightings. Humpback whale detections 
were lowest during the summer months (June through September), 
increased through the winter (January through March) and peaked in 
April (Bailey et al., 2018). Davis et al. (2020) also found detections 
of humpback whales off the mid-Atlantic (Virginia) to peak from January 
through May. Density modeling (Roberts et al., 2023) confirms April 
(0.00187 individuals per 1 km (0.54 nmi) grid cell) as the month of the 
highest average density of humpback whales in the vicinity of the 
Project Area.
    Since January 2016, elevated humpback whale mortalities along the 
Atlantic coast from Maine to Florida led to the declaration of a UME. 
As of October 2, 2023, 209 humpback whales have stranded as part of 
this UME. Partial or full necropsy examinations have been conducted on 
approximately 90 of the known cases. Of the whales examined, about 40 
percent had evidence of human interaction, either ship strike or 
entanglement. While a portion of the whales have shown evidence of pre-
mortem vessel strike, this finding is not consistent across all whales 
examined and more research is needed. As the humpback whale population 
has grown, they are seen more often in the mid-Atlantic. Since January 
2023, 34 humpbacks have stranded along the east coast of the United 
States (1 of these stranded in Maryland). These whales may have been 
following their prey (small fish) which were reportedly close to shore 
this past winter. These prey also attract fish that are targeted by 
recreational and commercial fishermen, which increases the number of 
boats in these areas. More information is available at https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events.

Fin Whale

    Fin whales frequently occur in the waters of the U.S. Atlantic 
Exclusive Economic Zone (EEZ), principally from Cape Hatteras, North 
Carolina northward and are distributed in both continental shelf and 
deep-water habitats (Hayes et al., 2023). Although fin whales are 
present north of the 35-degree latitude region in every season and are 
broadly distributed throughout the western North Atlantic for most of 
the year, densities vary seasonally (Edwards et al., 2015; Hayes et 
al., 2023). Fin whales typically feed in the Gulf of Maine and the 
waters surrounding New England, but their mating and calving (and 
general wintering) areas are largely unknown (Hain et al., 1992; Hayes 
et al., 2023). Acoustic detections of fin whale singers augment and 
confirm these visual sighting conclusions for males. Recordings from 
Massachusetts Bay, New York Bight, and deep-ocean areas have detected 
some level of fin whale singing from September through June (Watkins et 
al., 1987; Clark and Gagnon, 2002; Morano et al., 2012). These acoustic 
observations from both coastal and deep-ocean regions support the 
conclusion that male fin whales are broadly distributed throughout the 
western North Atlantic for most of the year (Hayes et al., 2022).
    Fin whale feeding BIAs occur offshore of Montauk Point, New York 
from March to October (2,933 km\2\) (Hain et al., 1992; LaBrecque et 
al., 2015) and year-round in the southern Gulf of Maine (18,015 km\2\). 
However, given the more southerly location of the Project Area (located 
approximately 364.8 km (226.7 mi) and 546.2 km (339.4 mi) away from 
these BIAs, respectively), there is no spatial overlap from with these 
BIAs.
    Fin whales were among the most frequently observed baleen whale 
species during the Maryland Wind Energy Area aerial surveys conducted 
for the Maryland Department of Natural Resources (MD DNR) by the 
Virginia Aquarium and Marine Science Center Foundation (Barco et al., 
2015), and the most commonly detected baleen whale species during 
acoustic monitoring surveys from 2014 to 2017 in the Maryland WEA, 
although the majority of detections were offshore of the WEA (Bailey et 
al., 2018a). Fin whale abundance in the vicinity of the Project Area 
peaked during the winter and early spring (Williams et al., 2015d; 
Barco et al., 2015), with the lowest occurrence documented during 
summer and early fall (Bailey et al., 2018). Consistent with visual 
sightings and acoustic detections,

[[Page 519]]

the highest average density of fin whales in the vicinity of the 
proposed Project Area occurs in January (0.00214 individuals per 1 km 
(0.54 nmi) grid cell) (Roberts et al., 2023). There is no active fin 
whale UME.

Minke Whale

    Minke whales are common and widely distributed throughout the U.S. 
Atlantic EEZ (Cetacean and Turtle Assessment Program (CETAP), 1982; 
Hayes et al., 2022), although their distribution has a strong seasonal 
component. Individuals have often been detected acoustically in shelf 
waters from spring to fall and more often detected in deeper offshore 
waters from winter to spring (Risch et al., 2013). Minke whales are 
abundant in New England waters from May through September (Pittman et 
al., 2006; Waring et al., 2014), yet largely absent from these areas 
during the winter, suggesting the possible existence of a migratory 
corridor (LaBrecque et al., 2015). A migratory route for minke whales 
transiting between northern feeding grounds and southern breeding areas 
may exist to the east of the Project Area, as minke whales may track 
warmer waters along the continental shelf while migrating (Risch et 
al., 2014). Risch et al. (2014) suggests the presence of a minke whale 
breeding ground offshore of the southeastern US during the winter.
    There are two minke whale feeding BIAs identified in the southern 
and southwestern section of the Gulf of Maine, including Georges Bank, 
the Great South Channel, Cape Cod Bay and Massachusetts Bay, Stellwagen 
Bank, Cape Anne, and Jeffreys Ledge from March through November, 
annually (LaBrecque et al., 2015). However, these BIAs are 
approximately 512.1 km (318.2 mi) and 668.8 km (415.6 mi) northwest of 
the Project Area, respectively, and would not be impacted by the 
proposed project activities.
    Overall, minke whale use of the Project Area is likely highest 
during fall, winter, and spring months based upon visual sightings and 
acoustic detections in the vicinity of the lease area during the months 
of November, January, February, and April (Bailey et al., 2018a; Barco 
et al., 2015; Williams et al., 2015b). The highest average density of 
minke whales in the vicinity of the lease area is expected to occur in 
May (0.00750 individuals per 1 km (0.54 nmi)).
    From 2017 through 2022, elevated minke whale mortalities detected 
along the Atlantic coast from Maine through South Carolina resulted in 
the declaration of a UME. As of October 2, 2023, a total of 160 minke 
whale mortalities have occurred during this UME. Full or partial 
necropsy examinations were conducted on more than 60 percent of the 
whales. Preliminary findings in several of the whales have shown 
evidence of human interactions or infectious disease, but these 
findings are not consistent across all of the minke whales examined, so 
more research is needed. More information is available at https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast.

Sei Whale

    The Nova Scotia stock of sei whales can be found in deeper waters 
of the continental shelf edge of the eastern United States and 
northeastward to south of Newfoundland (Mitchell, 1975; Hain et al., 
1985; Hayes et al., 2022). During spring and summer, the stock is 
mainly concentrated in northern feeding areas, including the Scotian 
Shelf (Mitchell and Chapman, 1977), the Gulf of Maine, Georges Bank, 
the Northeast Channel, and south of Nantucket (CETAP, 1982; Kraus et 
al., 2016; Roberts et al., 2016; Palka et al., 2017; Cholewiak et al., 
2018; Hayes et al., 2022). Sei whales have been detected acoustically 
along the Atlantic Continental Shelf and Slope from south of Cape 
Hatteras, North Carolina to the Davis Strait, with acoustic occurrence 
increasing in the mid-Atlantic region since 2010 (Davis et al., 2020). 
Although their migratory movements are not well understood, sei whales 
are believed to migrate north in June and July to feeding areas and 
south in September and October to breeding areas (Mitchell, 1975; 
CETAP, 1982; Davis et al., 2020). Sei whales generally occur offshore; 
however, individuals may also move into shallower, more inshore waters 
(Payne et al., 1990; Halpin et al., 2009; Hayes et al., 2022).
    A sei whale feeding BIA occurs in New England waters from May 
through November (LaBrecque et al., 2015). However, this BIA is located 
approximately 501.5 km (311.6 mi) north of the Project Area and not 
likely to be impacted by the Project activities.
    Sei whales were sighted infrequently during visual surveys 
(Williams et al., 2015d) and acoustic monitoring (WHOI, 2022; WHOI, 
2023) of the Maryland WEA. The highest average density of sei whales in 
the vicinity of the lease area is expected to occur during the month of 
April (0.00061 individuals per 1 km (0.54 nmi) (Roberts et al., 2023). 
There is no active sei whale UME.

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 
Project Area, the populations affected by the UME are the same as those 
potentially affected by the project. Information on this UME is 
available online at https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast.
    The above event was preceded by a different UME, occurring from 
2018 to 2020 (closure of the 2018-2020 UME is pending). Beginning in 
July 2018, elevated numbers of harbor seal and gray seal mortalities 
occurred across Maine, New Hampshire, and Massachusetts. Additionally, 
stranded seals have shown clinical signs as far south as Virginia, 
although not in elevated numbers, therefore the UME investigation 
encompassed all seal strandings from Maine to Virginia. A total of 
3,152 reported strandings (of all species) occurred from July 1, 2018, 
through March 13, 2020. Full or partial necropsy examinations have been 
conducted on some of the seals and samples have been collected for 
testing. Based on tests conducted thus far, the main pathogen found in 
the seals is phocine distemper virus. NMFS is performing additional 
testing to identify any other factors that may be involved in this UME, 
which is pending closure. Information on this UME is available online 
at: https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019a) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges

[[Page 520]]

(behavioral response data, anatomical modeling, etc.). Note that no 
direct measurements of hearing ability have been successfully completed 
for mysticetes (i.e., low-frequency cetaceans). Subsequently, NMFS 
(2018) described generalized hearing ranges for these marine mammal 
hearing groups. Generalized hearing ranges were chosen based on the 
approximately 65-decibel (dB) threshold from the normalized composite 
audiograms, with the exception for lower limits for low-frequency 
cetaceans where the lower bound was deemed to be biologically 
implausible and the lower bound from Southall et al. (2007) retained. 
Marine mammal hearing groups and their associated hearing ranges are 
provided in table 7.

                  Table 7--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 (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65-dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013). For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.
    NMFS notes that in 2019a, Southall et al. recommended new names for 
hearing groups that are widely recognized. However, this new hearing 
group classification does not change the weighting functions or 
acoustic thresholds (i.e., the weighting functions and thresholds in 
Southall et al. (2019a) are identical to NMFS 2018 Revised Technical 
Guidance). When NMFS updates our Technical Guidance, we will be 
adopting the updated Southall et al. (2019a) hearing group 
classification.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take of Marine Mammals section later in 
this document includes a quantitative analysis of the number of 
individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take of Marine Mammals section, 
and the Proposed Mitigation section, to draw conclusions regarding the 
likely impacts of these activities on the reproductive success or 
survivorship of individuals and how those impacts on individuals are 
likely to impact marine mammal species or stocks. General background 
information on marine mammal hearing was provided previously (see the 
Description of Marine Mammals in the Geographic Area section). Here, 
the potential effects of sound on marine mammals are discussed.
    US Wind has requested, and NMFS proposes to authorize, the take of 
marine mammals incidental to the construction activities associated 
with the project area. In their application, US Wind presented their 
analyses of potential impacts to marine mammals from the acoustic 
sources. NMFS both carefully reviewed the information provided by US 
Wind, as well as independently reviewed applicable scientific research 
and literature and other information to evaluate the potential effects 
of the Project's activities on marine mammals.
    The proposed activities would result in the construction and 
placement of up to 119 permanent foundations to support WTGs, OSSs, a 
Met tower, and seafloor mapping using HRG surveys. There are a variety 
of types and degrees of effects to marine mammals, prey species, and 
habitat that could occur as a result of the Project. Below we provide a 
brief description of the types of sound sources that would be generated 
by the project, the general impacts from these types of activities, and 
an analysis of the anticipated impacts on marine mammals from the 
project, with consideration of the proposed mitigation measures.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see: Au and Hastings, 2008; Richardson et al., 1995; Urick, 
1983; as well as the Discovery of Sound in the Sea (DOSITS) website at 
https://www.dosits.org. Sound is a vibration that travels as an 
acoustic wave through a medium such as a gas, liquid, or solid. Sound 
waves alternately compress and decompress the medium as the wave 
travels. These compressions and decompressions are detected as changes 
in pressure by aquatic life and man-made sound receptors such as 
hydrophones (underwater microphones). In water, sound waves radiate in 
a manner similar to ripples on the surface of a pond and may be either 
directed in a beam (narrow beam or directional sources) or sound beams 
may radiate in all directions (omnidirectional sources).
    Sound travels in water more efficiently than almost any other form 
of energy, making the use of acoustics ideal for the aquatic 
environment and its inhabitants. In seawater, sound travels at roughly 
1,500 meters per second (m/s). In-air, sound waves travel much more 
slowly, at about 340 m/s. However, the speed of sound can vary by a 
small amount based on characteristics of the transmission

[[Page 521]]

medium, such as water temperature and salinity. Sound travels in water 
more efficiently than almost any other form of energy, making the use 
of acoustics ideal for the aquatic environment and its inhabitants. In 
seawater, sound travels at roughly 1,500 m/s. In-air, sound waves 
travel much more slowly, at about 340 m/s. However, the speed of sound 
can vary by a small amount based on characteristics of the transmission 
medium, such as water temperature and salinity.
    The basic components of a sound wave are frequency, wavelength, 
velocity, and amplitude. Frequency is the number of pressure waves that 
pass by a reference point per unit of time and is measured in hertz 
(Hz) or cycles per second. Wavelength is the distance between two peaks 
or corresponding points of a sound wave (length of one cycle). Higher 
frequency sounds have shorter wavelengths than lower frequency sounds, 
and typically attenuate (decrease) more rapidly, except in certain 
cases in shallower water.
    The intensity (or amplitude) of sounds is measured in dB, which 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 hundred-fold increase in 
power and a 30-dB increase is a thousand-fold increase in power. 
However, a ten-fold increase in acoustic power does not mean that the 
sound is perceived as being 10 times louder. Decibels are a relative 
unit comparing two pressures; therefore, a reference pressure must 
always be indicated. For underwater sound, this is 1 microPascal 
([mu]Pa). For in-air sound, the reference pressure is 20 microPascal 
([mu]Pa). The amplitude of a sound can be presented in various ways; 
however, NMFS typically considers three metrics. In this proposed rule, 
all decibel levels are referenced to (re) 1[mu]Pa.
    Sound exposure level (SEL) represents the total energy in a stated 
frequency band over a stated time interval or event and considers both 
amplitude and duration of exposure (represented as dB re 1 [mu]Pa\2\-
s). SEL is a cumulative metric; it can be accumulated over a single 
pulse (for pile driving this is often referred to as single-strike SEL; 
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, 2019a) for an in-depth discussion 
of these concepts. Impulsive sound sources (e.g., airguns, explosions, 
gunshots, sonic booms, impact pile driving) produce signals that are 
brief (typically considered to be less than 1 second), broadband, 
atonal transients (American National Standards Institute (ANSI), 1986; 
ANSI, 2005; Harris, 1998; National Institute for Occupational Safety 
and Health (NIOSH), 1998; International Organization for 
Standardization (ISO), 2003) and occur either as isolated events or 
repeated in some succession. Impulsive sounds are all characterized by 
a relatively rapid rise from ambient pressure to a maximal pressure 
value followed by a rapid decay period that may include a period of 
diminishing, oscillating maximal and minimal pressures, and generally 
have an increased capacity to induce physical injury as compared with 
sounds that lack these features. Impulsive sounds are typically 
intermittent in nature.
    Non-impulsive sounds can be tonal, narrowband, or broadband, brief, 
or prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-impulsive sounds can be transient 
signals of short duration but without the essential properties of 
pulses (e.g., rapid rise time). Examples of non-impulsive sounds 
include those produced by vessels, aircraft, machinery operations such 
as drilling or dredging, vibratory pile driving, and active sonar 
systems. Sounds are also characterized by their temporal component. 
Continuous sounds are those whose sound pressure level remains above 
that of the ambient sound with negligibly small fluctuations in level 
(NIOSH, 1998; ANSI, 2005) while intermittent sounds are defined as 
sounds with interrupted levels of low or no sound (NIOSH, 1998). NMFS 
identifies Level B harassment thresholds based on if a sound is 
continuous or intermittent.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The sound level of a region 
is defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
Hz and 50 kHz (International Council for the Exploration of the Sea 
(ICES), 1995). In general, ambient sound levels tend to increase with 
increasing wind speed and wave height. Precipitation can become an 
important component of total sound at frequencies above 500 Hz and 
possibly down to 100 Hz during quiet times. Marine mammals can 
contribute significantly to ambient sound levels as can some fish and 
snapping shrimp. The frequency band for biological contributions is 
from approximately 12 Hz to over 100 kHz. Sources of ambient sound 
related to human activity include transportation (surface vessels), 
dredging and construction, oil and gas drilling and production, 
geophysical surveys, sonar, and explosions. Vessel noise typically 
dominates the total ambient sound for

[[Page 522]]

frequencies between 20 and 300 Hz. In general, the frequencies of 
anthropogenic sounds are below 1 kHz, and if higher frequency sound 
levels are created, they attenuate rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human activity) but also on the ability of 
sound to propagate through the environment. In turn, sound propagation 
is dependent on the spatially and temporally varying properties of the 
water column and sea floor and is frequency-dependent. As a result of 
the dependence on a large number of varying factors, ambient sound 
levels can be expected to vary widely over both coarse and fine spatial 
and temporal scales. Sound levels at a given frequency and location can 
vary by 10-20 dB from day to day (Richardson et al., 1995). The result 
is that, depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals. Human-generated sound is a significant contributor to the 
acoustic environment in the project location.

Potential Effects of Underwater Sound on Marine Mammals

    Anthropogenic sounds cover a broad range of frequencies and sound 
levels and can have a range of highly variable impacts on marine life 
from none or minor to potentially severe responses depending on 
received levels, duration of exposure, behavioral context, and various 
other factors. Broadly, underwater sound from active acoustic sources, 
such as those in the Project, can potentially result in one or more of 
the following: temporary or permanent hearing impairment, non-auditory 
physical or physiological effects, behavioral disturbance, stress, and 
masking (Richardson et al., 1995; Gordon et al., 2003; Nowacek et al., 
2007; Southall et al., 2007; G[ouml]tz et al., 2009). Non-auditory 
physiological effects or injuries that theoretically might occur in 
marine mammals exposed to high level underwater sound or as a secondary 
effect of extreme behavioral reactions (e.g., change in dive profile as 
a result of an avoidance reaction) caused by exposure to sound include 
neurological effects, bubble formation, resonance effects, and other 
types of organ or tissue damage (Cox et al., 2006; Southall et al., 
2007; Zimmer and Tyack, 2007; Tal et al., 2015).
    In general, the degree of effect of an acoustic exposure is 
intrinsically related to the signal characteristics, received level, 
distance from the source, and duration of the sound exposure, in 
addition to the contextual factors of the receiver (e.g., behavioral 
state at time of exposure, age class, etc.). In general, sudden, high-
level sounds can cause hearing loss as can longer exposures to lower-
level sounds. Moreover, any temporary or permanent loss of hearing will 
occur almost exclusively for noise within an animal's hearing range. We 
describe below the specific manifestations of acoustic effects that may 
occur based on the activities proposed by US Wind. Richardson et al. 
(1995) described zones of increasing intensity of effect that might be 
expected to occur in relation to distance from a source and assuming 
that the signal is within an animal's hearing range. First (at the 
greatest distance) is the area within which the acoustic signal would 
be audible (potentially perceived) to the animal but not strong enough 
to elicit any overt behavioral or physiological response. The next zone 
(closer to the receiving animal) corresponds with the area where the 
signal is audible to the animal and of sufficient intensity to elicit 
behavioral or physiological responsiveness. The third is a zone within 
which, for signals of high intensity, the received level is sufficient 
to potentially cause discomfort or tissue damage to auditory or other 
systems. Overlaying these zones to a certain extent is the area within 
which masking (i.e., when a sound interferes with or masks the ability 
of an animal to detect a signal of interest that is above the absolute 
hearing threshold) may occur; the masking zone may be highly variable 
in size.
    Below, we provide additional detail regarding potential impacts on 
marine mammals and their habitat from noise in general, starting with 
hearing impairment, as well as from the specific activities US Wind 
plans to conduct, to the degree it is available (noting that there is 
limited information regarding the impacts of offshore wind construction 
on marine mammals).
Hearing Threshold Shift
    Marine mammals exposed to high-intensity sound or to lower-
intensity sound for prolonged periods can experience hearing threshold 
shift (TS), which NMFS defines as a change, usually an increase, in the 
threshold of audibility at a specified frequency or portion of an 
individual's hearing range above a previously established reference 
level expressed in decibels (NMFS, 2018). Threshold shifts can be 
permanent, in which case there is an irreversible increase in the 
threshold of audibility at a specified frequency or portion of an 
individual's hearing range or temporary, in which there is reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range and the animal's hearing 
threshold would fully recover over time (Southall et al., 2019a). 
Repeated sound exposure that leads to TTS could cause PTS.
    When PTS occurs, there can be physical damage to the sound 
receptors in the ear (i.e., tissue damage) whereas TTS represents 
primarily tissue fatigue and is reversible (Henderson et al., 2008). In 
addition, other investigators have suggested that TTS is within the 
normal bounds of physiological variability and tolerance and does not 
represent physical injury (e.g., Ward, 1997; Southall et al., 2019a). 
Therefore, NMFS does not consider TTS to constitute auditory injury. 
Relationships between TTS and PTS thresholds have not been studied in 
marine mammals, and there is no PTS data for cetaceans. However, such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. Noise exposure can result in either a permanent 
shift in hearing thresholds from baseline (a 40-dB threshold shift 
approximates a PTS onset; e.g., Kryter et al., 1966; Miller, 1974; 
Henderson et al., 2008) or a temporary, recoverable shift in hearing 
that returns to baseline (a 6-dB threshold shift approximates a TTS 
onset; e.g., Southall et al., 2019a). Based on data from terrestrial 
mammals, a precautionary assumption is that the PTS thresholds, 
expressed in the unweighted peak sound pressure level metric (PK), for 
impulsive sounds (such as impact pile driving pulses) are at least 6 dB 
higher than the TTS thresholds and the weighted PTS cumulative sound 
exposure level thresholds are 15 (impulsive sound) to 20 (non-impulsive 
sounds) dB higher than TTS cumulative sound exposure level thresholds 
(Southall et al., 2019a). Given the higher level of sound or longer 
exposure duration necessary to cause PTS as compared with TTS, PTS is 
less likely to occur as a result of these activities; however, it is 
possible, and a small amount has been proposed for authorization for 
several species.
    TTS is the mildest form of hearing impairment that can occur during 
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

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experiencing TTS, the hearing threshold rises, and a sound must be at a 
higher level in order to be heard. In terrestrial and marine mammals, 
TTS can last from minutes or hours to days (in cases of strong TTS). In 
many cases, hearing sensitivity recovers rapidly after exposure to the 
sound ends. There is data on sound levels and durations necessary to 
elicit mild TTS for marine mammals, but recovery is complicated to 
predict and dependent on multiple factors.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
depending on the degree of interference of marine mammals hearing. For 
example, a marine mammal may be able to readily compensate for a brief, 
relatively small amount of TTS in a non-critical frequency range that 
occurs during a time where ambient noise is lower and there are not as 
many competing sounds present. Alternatively, a larger amount and 
longer duration of TTS sustained during time when communication is 
critical (e.g., for successful mother/calf interactions, consistent 
detection of prey) could have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor 
porpoise, and Yangtze finless porpoise (Neophocaena asiaeorientalis)) 
and six species of pinnipeds (northern elephant seal (Mirounga 
angustirostris), harbor seal, ring seal, spotted seal, bearded seal, 
and California sea lion (Zalophus californianus)) that were exposed to 
a limited number of sound sources (i.e., mostly tones and octave-band 
noise with limited number of exposure to impulsive sources such as 
seismic airguns or impact pile driving) in laboratory settings 
(Southall et al., 2019a). There is currently no data available on 
noise-induced hearing loss for mysticetes. For summaries of data on TTS 
or PTS in marine mammals or for further discussion of TTS or PTS onset 
thresholds, please see Southall et al. (2019a) and NMFS (2018).
    Recent studies with captive odontocete species (bottlenose dolphin, 
harbor porpoise, beluga, and false killer whale) have observed 
increases in hearing threshold levels when individuals received a 
warning sound prior to exposure to a relatively loud sound (Nachtigall 
and Supin, 2013; Nachtigall and Supin, 2015; Nachtigall et al., 2016a; 
Nachtigall et al., 2016b; Nachtigall et al., 2016c; Finneran, 2018; 
Nachtigall et al., 2018). These studies suggest that captive animals 
have a mechanism to reduce hearing sensitivity prior to impending loud 
sounds. Hearing change was observed to be frequency dependent and 
Finneran (2018) suggests hearing attenuation occurs within the cochlea 
or auditory nerve. Based on these observations on captive odontocetes, 
the authors suggest that wild animals may have a mechanism to self-
mitigate the impacts of noise exposure by dampening their hearing 
during prolonged exposures of loud sound or if conditioned to 
anticipate intense sounds (Finneran, 2018; Nachtigall et al., 2018).
Behavioral Effects
    Exposure of marine mammals to sound sources can result in, but is 
not limited to, no response or any of the following observable 
responses: increased alertness; orientation or attraction to a sound 
source; vocal modifications; cessation of feeding; cessation of social 
interaction; alteration of movement or diving behavior; habitat 
abandonment (temporary or permanent); and in severe cases, panic, 
flight, stampede, or stranding, potentially resulting in death 
(Southall et al., 2007). A review of marine mammal responses to 
anthropogenic sound was first conducted by Richardson (1995). More 
recent reviews address studies conducted since 1995 and focused on 
observations where the received sound level of the exposed marine 
mammal(s) was known or could be estimated (Nowacek et al., 2007; 
DeRuiter et al., 2013; Ellison et al., 2012; Gomez et al., 2016). Gomez 
et al. (2016) conducted a review of the literature considering the 
contextual information of exposure in addition to received level and 
found that higher received levels were not always associated with more 
severe behavioral responses and vice versa. Southall et al. (2021) 
states that results demonstrate that some individuals of different 
species display clear yet varied responses, some of which have negative 
implications while others appear to tolerate high levels and that 
responses may not be fully predictable with simple acoustic exposure 
metrics (e.g., received sound level). Rather, the authors state that 
differences among species and individuals along with contextual aspects 
of exposure (e.g., behavioral state) appear to affect response 
probability.
    Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception 
of and response to (nature and magnitude) an acoustic event. An 
animal's prior experience with a sound or sound source affects whether 
it is less likely (habituation) or more likely (sensitization) to 
respond to certain sounds in the future (animals can also be innately 
predisposed to respond to certain sounds in certain ways) (Southall et 
al., 2019a). Related to the sound itself, the perceived nearness of the 
sound, bearing of the sound (approaching vs. retreating), the 
similarity of a sound to biologically relevant sounds in the animal's 
environment (i.e., calls of predators, prey, or conspecifics), and 
familiarity of the sound may affect the way an animal responds to the 
sound (Southall et al., 2007; DeRuiter et al., 2013). Individuals (of 
different age, gender, reproductive status, etc.) among most 
populations will have variable hearing capabilities, and differing 
behavioral sensitivities to sounds that will be affected by prior 
conditioning, experience, and current activities of those individuals. 
Often, specific acoustic features of the sound and contextual variables 
(i.e., proximity, duration, or recurrence of the sound or the current 
behavior that the marine mammal is engaged in or its prior experience), 
as well as entirely separate factors, such as the physical presence of 
a nearby vessel, may be more relevant to the animal's response than the 
received level alone.
    Overall, the variability of responses to acoustic stimuli depends 
on the species receiving the sound, the sound source, and the social, 
behavioral, or environmental contexts of exposure (e.g., DeRuiter and 
Doukara, 2012). For example, Goldbogen et al. (2013a) demonstrated that 
individual behavioral state was critically important in determining 
response of blue whales to sonar, noting that some individuals engaged 
in deep (greater than 50 m) feeding behavior had greater dive responses 
than those in shallow feeding or non-feeding conditions. Some blue 
whales in the Goldbogen et al. (2013a) study that were engaged in 
shallow feeding behavior demonstrated no clear changes in diving or 
movement even when received levels were high (~160 dB re 1[micro]Pa 
(microPascal)) for exposures to 3-4 kHz sonar signals, while deep 
feeding and non-feeding whales showed a clear response at exposures at 
lower received levels of sonar and pseudorandom noise. Southall et al. 
(2011) found that blue whales had a different response to sonar 
exposure

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depending on behavioral state, more pronounced when deep feeding/travel 
modes than when engaged in surface feeding.
    With respect to distance influencing disturbance, DeRuiter et al. 
(2013) examined behavioral responses of Cuvier's beaked whales to mid-
frequency sonar and found that whales responded strongly at low 
received levels (89-127 dB re 1[micro]Pa) by ceasing normal fluking and 
echolocation, swimming rapidly away, and extending both dive duration 
and subsequent non-foraging intervals when the sound source was 3.4-9.5 
km away. Importantly, this study also showed that whales exposed to a 
similar range of received levels (78-106 dB re 1[micro]Pa) from distant 
sonar exercises (118 km away) did not elicit such responses, suggesting 
that context may moderate reactions. Thus, distance from the source is 
an important variable in influencing the type and degree of behavioral 
response and this variable is independent of the effect of received 
levels (e.g., DeRuiter et al., 2013; Dunlop et al., 2017a; Dunlop et 
al., 2017b; Falcone et al., 2017; Dunlop et al., 2018; Southall et al., 
2019a).
    Ellison et al. (2012) outlined an approach to assessing the effects 
of sound on marine mammals that incorporates contextual-based factors. 
The authors recommend considering not just the received level of sound, 
but also the activity the animal is engaged in at the time the sound is 
received, the nature and novelty of the sound (i.e., is this a new 
sound from the animal's perspective), and the distance between the 
sound source and the animal. They submit that this ``exposure 
context,'' as described, greatly influences the type of behavioral 
response exhibited by the animal. Forney et al. (2017) also point out 
that an apparent lack of response (e.g., no displacement or avoidance 
of a sound source) may not necessarily mean there is no cost to the 
individual or population, as some resources or habitats may be of such 
high value that animals may choose to stay, even when experiencing 
stress or hearing loss. Forney et al. (2017) recommend considering both 
the costs of remaining in an area of noise exposure such as TTS, PTS, 
or masking, which could lead to an increased risk of predation or other 
threats or a decreased capability to forage, and the costs of 
displacement, including potential increased risk of vessel strike, 
increased risks of predation or competition for resources, or decreased 
habitat suitable for foraging, resting, or socializing. This sort of 
contextual information is challenging to predict with accuracy for 
ongoing activities that occur over large spatial and temporal expanses. 
However, distance is one contextual factor for which data exist to 
quantitatively inform a take estimate, and the method for predicting 
Level B harassment in this rule does consider distance to the source. 
Other factors are often considered qualitatively in the analysis of the 
likely consequences of sound exposure where supporting information is 
available.
    Behavioral change, such as disturbance manifesting in lost foraging 
time, in response to anthropogenic activities is often assumed to 
indicate a biologically significant effect on a population of concern. 
However, individuals may be able to compensate for some types and 
degrees of shifts in behavior, preserving their health and thus their 
vital rates and population dynamics. For example, New et al. (2013) 
developed a model simulating the complex social, spatial, behavioral, 
and motivational interactions of coastal bottlenose dolphins in the 
Moray Firth, Scotland, to assess the biological significance of 
increased rate of behavioral disruptions caused by vessel traffic. 
Despite a modeled scenario in which vessel traffic increased from 70 to 
470 vessels a year (a six-fold increase in vessel traffic) in response 
to the construction of a proposed offshore renewables' facility, the 
dolphins' behavioral time budget, spatial distribution, motivations, 
and social structure remained unchanged. Similarly, two bottlenose 
dolphin populations in Australia were also modeled over 5 years against 
a number of disturbances (Reed et al., 2020) and results indicate that 
habitat/noise disturbance had little overall impact on population 
abundances in either location, even in the most extreme impact 
scenarios modeled. Friedlaender et al. (2016) provided the first 
integration of direct measures of prey distribution and density 
variables incorporated into across-individual analyses of behavior 
responses of blue whales to sonar and demonstrated a fivefold increase 
in the ability to quantify variability in blue whale diving behavior. 
These results illustrate that responses evaluated without such 
measurements for foraging animals may be misleading, which again 
illustrates the context-dependent nature of the probability of 
response.
    The following subsections provide examples of behavioral responses 
that give an idea of the variability in behavioral responses that would 
be expected given the differential sensitivities of marine mammal 
species to sound, contextual factors, and the wide range of potential 
acoustic sources to which a marine mammal may be exposed. Behavioral 
responses that could occur for a given sound exposure should be 
determined from the literature that is available for each species, or 
extrapolated from closely related species when no information exists, 
along with contextual factors.
Avoidance and Displacement
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
(Eschrichtius robustus) and humpback whales are known to change 
direction--deflecting from customary migratory paths--in order to avoid 
noise from airgun surveys (Malme et al., 1984; Dunlop et al., 2018). 
Avoidance is qualitatively different from the flight response but also 
differs in the magnitude of the response (i.e., directed movement, rate 
of travel, etc.). Avoidance may be short-term with animals returning to 
the area once the noise has ceased (e.g., Malme et al., 1984; Bowles et 
al., 1994; Goold, 1996; Stone et al., 2000; Morton and Symonds, 2002; 
Gailey et al., 2007; D[auml]hne et al., 2013; Russel et al., 2016). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006; Forney et al., 2017). Avoidance of marine mammals during 
the construction of offshore wind facilities (specifically, impact pile 
driving) has been documented in the literature with some significant 
variation in the temporal and spatial degree of avoidance and with most 
studies focused on harbor porpoises as one of the most common marine 
mammals in European waters (e.g., Tougaard et al., 2009; D[auml]hne et 
al., 2013; Thompson et al., 2013; Russell et al., 2016; Brandt et al., 
2018).
    Available information on impacts to marine mammals from pile 
driving associated with offshore wind is limited to information on 
harbor porpoises and seals, as the vast majority of this research has 
occurred at European offshore wind projects where large whales and 
other odontocete species are uncommon. Harbor porpoises and harbor 
seals are considered to be behaviorally sensitive species (e.g., 
Southall et al., 2007) and the effects of wind farm construction in 
Europe on

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these species have been well documented. These species have received 
particular attention in European waters due to their abundance in the 
North Sea (Hammond et al., 2002; Nachtsheim et al., 2021). A summary of 
the literature on documented effects of wind farm construction on 
harbor porpoise and harbor seals is described below.
    Brandt et al. (2016) summarized the effects of the construction of 
eight offshore wind projects within the German North Sea (i.e., Alpha 
Ventus, BARD Offshore I, Borkum West II, DanTysk, Global Tech I, 
Meerwind S[uuml]d/Ost, Nordsee Ost, and Riffgat) between 2009 and 2013 
on harbor porpoises, combining passive acoustic monitoring (PAM) data 
from 2010 to 2013 and aerial surveys from 2009 to 2013 with data on 
noise levels associated with pile driving. Results of the analysis 
revealed significant declines in porpoise detections during pile 
driving when compared to 25-48 hours before pile driving began, with 
the magnitude of decline during pile driving clearly decreasing with 
increasing distances to the construction site. During the majority of 
projects, significant declines in detections (by at least 20 percent) 
were found within at least 5-10 km of the pile driving site, with 
declines at up to 20-30 km of the pile driving site documented in some 
cases. Similar results demonstrating the long-distance displacement of 
harbor porpoises (18-25 km) and harbor seals (up to 40 km) during 
impact pile driving have also been observed during the construction at 
multiple other European wind farms (Tougaard et al., 2009; Bailey et 
al., 2010; D[auml]hne et al., 2013; Lucke et al., 2012; Haelters et 
al., 2015).
    While harbor porpoises and seals tend to move several kilometers 
away from wind farm construction activities, the duration of 
displacement has been documented to be relatively temporary. In two 
studies at Horns Rev II using impact pile driving, harbor porpoise 
returned within 1 to 2 days following cessation of pile driving 
(Tougaard et al., 2009; Brandt et al., 2011). Similar recovery periods 
have been noted for harbor seals off England during the construction of 
four wind farms (Brasseur et al., 2012; Carroll et al., 2010; Hamre et 
al., 2011; Hastie et al., 2015; Russell et al., 2016). In some cases, 
an increase in harbor porpoise activity has been documented inside wind 
farm areas following construction (e.g., Lindeboom et al., 2011). Other 
studies have noted longer term impacts after impact pile driving. Near 
Dogger Bank in Germany, harbor porpoises continued to avoid the area 
for over 2 years after construction began (Gilles et al., 2009). 
Approximately 10 years after construction of the Nysted wind farm, 
harbor porpoise abundance had not recovered to the original levels 
previously seen, although the echolocation activity was noted to have 
been increasing when compared to the previous monitoring period 
(Teilmann and Carstensen, 2012). However, overall, there are no 
indications for a population decline of harbor porpoises in European 
waters (e.g., Brandt et al., 2016). Notably, where significant 
differences in displacement and return rates have been identified for 
these species, the occurrence of secondary project-specific influences 
such as use of mitigation measures (e.g., bubble curtains, acoustic 
deterrent devices (ADDs)), or the manner in which species use the 
habitat in the project area, are likely the driving factors of this 
variation.
    NMFS notes the aforementioned studies from Europe involve 
installing much smaller piles than US 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 Maryland. However, we do not anticipate 
any greater severity of response due to harbor porpoise and harbor seal 
habitat use off Maryland 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 Maryland, harbor porpoises are transient (with higher 
abundances in winter when foundation installation would not occur) and 
a very small percentage of the large harbor seal population are only 
seasonally present with no rookeries established. In summary, we 
anticipate that harbor porpoise and harbor seals will likely respond to 
pile driving by moving several kilometers away from the source but 
return to typical habitat use patterns when pile driving ceases.
    Some avoidance behavior of other marine mammal species has been 
documented to be dependent on distance from the source. As described 
above, DeRuiter et al. (2013) noted that distance from a sound source 
may moderate marine mammal reactions in their study of Cuvier's beaked 
whales (an acoustically sensitive species), which showed the whales 
swimming rapidly and silently away when a sonar signal was 3.4-9.5 km 
away while showing no such reaction to the same signal when the signal 
was 118 km away even though the received levels were similar. Tyack et 
al. (1983) conducted playback studies of Surveillance Towed Array 
Sensor System (SURTASS) low-frequency active (LFA) sonar in a gray 
whale migratory corridor off California. Similar to North Atlantic 
right whales, gray whales migrate close to shore (approximately +2 km) 
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). US Wind 
does not anticipate, and NMFS is not proposing to authorize take of 
beaked whales and, moreover, the sounds produced by US 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

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sound field associated with active sonar (Frid and Dill, 2002). Most 
animals can avoid that energetic cost by swimming away at slow speeds 
or speeds that minimize the cost of transport (Miksis-Olds, 2006), as 
has been demonstrated in Florida manatees (Miksis-Olds, 2006). Those 
energetic costs increase, however, when animals shift from a resting 
state, which is designed to conserve an animal's energy, to an active 
state that consumes energy the animal would have conserved had it not 
been disturbed. Marine mammals that have been disturbed by 
anthropogenic noise and vessel approaches are commonly reported to 
shift from resting to active behavioral states, which would imply that 
they incur an energy cost.
    Forney et al. (2017) detailed the potential effects of noise on 
marine mammal populations with high site fidelity, including 
displacement and auditory masking, noting that a lack of observed 
response does not imply absence of fitness costs and that apparent 
tolerance of disturbance may have population-level impacts that are 
less obvious and difficult to document. Avoidance of overlap between 
disturbing noise and areas and/or times of particular importance for 
sensitive species may be critical to avoiding population-level impacts 
because (particularly for animals with high site fidelity) there may be 
a strong motivation to remain in the area despite negative impacts. 
Forney et al. (2017) stated that, for these animals, remaining in a 
disturbed area may reflect a lack of alternatives rather than a lack of 
effects.
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, but observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996; Frid and Dill, 2002). The result of a flight response 
could range from brief, temporary exertion and displacement from the 
area where the signal provokes flight to, in extreme cases, beaked 
whale strandings (Cox et al., 2006; D'Amico et al., 2009). However, it 
should be noted that response to a perceived predator does not 
necessarily invoke flight (Ford and Reeves, 2008), and whether 
individuals are solitary or in groups may influence the response. 
Flight responses of marine mammals have been documented in response to 
mobile high intensity active sonar (e.g., Tyack et al., 2011; DeRuiter 
et al., 2013; Wensveen et al., 2019), and more severe responses have 
been documented when sources are moving towards an animal or when they 
are surprised by unpredictable exposures (Watkins, 1986; Falcone et 
al., 2017). Generally speaking, however, marine mammals would be 
expected to be less likely to respond with a flight response to either 
stationery pile driving (which they can sense is stationery and 
predictable) or significantly lower-level HRG surveys, unless they are 
within the area ensonified above behavioral harassment thresholds at 
the moment the source is turned on (Watkins, 1986; Falcone et al., 
2017).
Diving and Foraging
    Changes in dive behavior in response to noise exposure can vary 
widely. They may consist of increased or decreased dive times and 
surface intervals as well as changes in the rates of ascent and descent 
during a dive (e.g., Frankel and Clark, 2000; Costa et al., 2003; Ng 
and Leung, 2003; Nowacek et al., 2004; Goldbogen et al., 2013a; 
Goldbogen et al., 2013b). Variations in dive behavior may reflect 
interruptions in biologically significant activities (e.g., foraging) 
or they may be of little biological significance. Variations in dive 
behavior may also expose an animal to potentially harmful conditions 
(e.g., increasing the chance of ship-strike) or may serve as an 
avoidance response that enhances survivorship. The impact of a 
variation in diving resulting from an acoustic exposure depends on what 
the animal is doing at the time of the exposure, the type and magnitude 
of the response, and the context within which the response occurs 
(e.g., the surrounding environmental and anthropogenic circumstances).
    Nowacek et al. (2004) reported disruptions of dive behaviors in 
foraging North Atlantic right whales when exposed to an alerting 
stimulus, an action, they noted, that could lead to an increased 
likelihood of ship strike. The alerting stimulus was in the form of an 
18-minute exposure that included three 2-minute signals played three 
times sequentially. This stimulus was designed with the purpose of 
providing signals distinct to background noise that serve as 
localization cues. However, the whales did not respond to playbacks of 
either right whale social sounds or vessel noise, highlighting the 
importance of the sound characteristics in producing a behavioral 
reaction. Although source levels for the proposed pile driving 
activities may exceed the received level of the alerting stimulus 
described by Nowacek et al. (2004), proposed mitigation strategies 
(further described in the Proposed Mitigation section) will reduce the 
severity of response to proposed pile driving activities. Converse to 
the behavior of North Atlantic right whales, Indo-Pacific humpback 
dolphins have been observed to dive for longer periods of time in areas 
where vessels were present and/or approaching (Ng and Leung, 2003). In 
both of these studies, the influence of the sound exposure cannot be 
decoupled from the physical presence of a surface vessel, thus 
complicating interpretations of the relative contribution of each 
stimulus to the response. Indeed, the presence of surface vessels, 
their approach, and speed of approach, seemed to be significant factors 
in the response of the Indo-Pacific humpback dolphins (Ng and Leung, 
2003). Low-frequency signals of the Acoustic Thermometry of Ocean 
Climate (ATOC) sound source were not found to affect dive times of 
humpback whales in Hawaiian waters (Frankel and Clark, 2000) or to 
overtly affect elephant seal dives (Costa et al., 2003). They did, 
however, produce subtle effects that varied in direction and degree 
among the individual seals, illustrating the equivocal nature of 
behavioral effects and consequent difficulty in defining and predicting 
them.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the cessation of secondary 
indicators of foraging (e.g., bubble nets or sediment plumes), or 
changes in dive behavior. As for other types of behavioral response, 
the frequency, duration, and temporal pattern of signal presentation, 
as well as differences in species sensitivity, are likely contributing 
factors to differences in response in any given circumstance (e.g., 
Croll et al., 2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko 
et al., 2007; Southall et al., 2019b). An understanding of the 
energetic requirements of the affected individuals and the relationship 
between prey availability, foraging effort and success, and the life 
history stage of the animal can facilitate the assessment of whether 
foraging disruptions are likely to incur fitness consequences 
(Goldbogen et al., 2013b; Farmer et al., 2018; Pirotta et al., 2018a; 
Southall et al., 2019a; Pirotta et al., 2021).
    Impacts on marine mammal foraging rates from noise exposure have 
been documented, though there is little data regarding the impacts of 
offshore turbine construction specifically. Several broader examples 
follow, and it

[[Page 527]]

is reasonable to expect that exposure to noise produced during the 5 
years that 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 airgun arrays at received levels in 
the range 140-160 dB at distances of 7-13 km, following a phase-in of 
sound intensity and full array exposures at 1-13 km (Madsen et al., 
2006; Miller et al., 2009). Sperm whales did not exhibit horizontal 
avoidance behavior at the surface. However, foraging behavior may have 
been affected. The sperm whales exhibited 19 percent less vocal (buzz) 
rate during full exposure relative to post exposure, and the whale that 
was approached most closely had an extended resting period and did not 
resume foraging until the airguns had ceased firing. The remaining 
whales continued to execute foraging dives throughout exposure; 
however, swimming movements during foraging dives were 6 percent lower 
during exposure than during control periods (Miller et al., 2009). 
Miller et al. (2009) noted that more data are required to understand 
whether the differences were due to exposure or natural variation in 
sperm whale behavior. Balaenopterid whales exposed to moderate low-
frequency signals similar to the ATOC sound source demonstrated no 
variation in foraging activity (Croll et al., 2001), whereas five out 
of six North Atlantic right whales exposed to an acoustic alarm 
interrupted their foraging dives (Nowacek et al., 2004). Although the 
received SPLs were similar in the latter two studies, the frequency, 
duration, and temporal pattern of signal presentation were different. 
These factors, as well as differences in species sensitivity, are 
likely contributing factors to the differential response. The source 
levels of both the proposed construction and HRG activities exceed the 
source levels of the signals described by Nowacek et al. (2004) and 
Croll et al. (2001), and noise generated by US Wind's activities at 
least partially overlap in frequency with the described signals. Blue 
whales exposed to mid-frequency sonar in the Southern California Bight 
were less likely to produce low-frequency calls usually associated with 
feeding behavior (Melc[oacute]n et al., 2012). However, Melc[oacute]n 
et al. (2012) were unable to determine if suppression of low-frequency 
calls reflected a change in their feeding performance or abandonment of 
foraging behavior and indicated that implications of the documented 
responses are unknown. Further, it is not known whether the lower rates 
of calling actually indicated a reduction in feeding behavior or social 
contact since the study used data from remotely deployed, passive 
acoustic monitoring buoys. Results from the 2010-2011 field season of a 
behavioral response study in Southern California waters indicated that, 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2011; 
Southall et al., 2012b; Southall et al., 2019).
    Information on or estimates of the energetic requirements of the 
individuals and the relationship between prey availability, foraging 
effort and success, and the life history stage of the animal will help 
better inform a determination of whether foraging disruptions incur 
fitness consequences. Foraging strategies may impact foraging 
efficiency, such as by reducing foraging effort and increasing success 
in prey detection and capture, in turn promoting fitness and allowing 
individuals to better compensate for foraging disruptions. Surface 
feeding blue whales did not show a change in behavior in response to 
mid-frequency simulated and real sonar sources with received levels 
between 90 and 179 dB re 1 [micro]Pa, but deep feeding and non-feeding 
whales showed temporary reactions including cessation of feeding, 
reduced initiation of deep foraging dives, generalized avoidance 
responses, and changes to dive behavior (DeRuiter et al., 2017; 
Goldbogen et al., 2013b; Sivle et al., 2015). Goldbogen et al. (2013b) 
indicate that disruption of feeding and displacement could impact 
individual fitness and health. However, for this to be true, we would 
have to assume that an individual whale could not compensate for this 
lost feeding opportunity by either immediately feeding at another 
location, by feeding shortly after cessation of acoustic exposure, or 
by feeding at a later time. There is no indication that individual 
fitness and health would be impacted, particularly since unconsumed 
prey would likely still be available in the environment in most cases 
following the cessation of acoustic exposure.
    Similarly, while the rates of foraging lunges decrease in humpback 
whales due to sonar exposure, there was variability in the response 
across individuals, with one animal ceasing to forage completely and 
another animal starting to forage during the exposure (Sivle et al., 
2016). In addition, almost half of the animals that demonstrated 
avoidance were foraging before the exposure, but the others were not; 
the animals that avoided while not feeding responded at a slightly 
lower received level and greater distance than those that were feeding 
(Wensveen et al., 2017). These findings indicate the behavioral state 
of the animal and foraging strategies play a role in the type and 
severity of a behavioral response. For example, when the prey field was 
mapped and used as a covariate in examining how behavioral state of 
blue whales is influenced by mid-frequency sound, the response in blue 
whale deep-feeding behavior was even more apparent, reinforcing the 
need for contextual variables to be included when assessing behavioral 
responses (Friedlaender et al., 2016).
Vocalizations and Auditory Masking
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, production of echolocation clicks, calling, 
and singing. Changes in vocalization behavior in response to 
anthropogenic noise can occur for any of these modes and may result 
directly from increased vigilance or a startle response, or from a need 
to compete with an increase in background noise (see Erbe et al., 2016 
review on communication masking), the latter of which is described more 
below.
    For example, in the presence of potentially masking signals, 
humpback whales and killer whales have been observed to increase the 
length of their songs (Miller et al., 2000; Fristrup et al., 2003; 
Foote et al., 2004) and blue whales increased song production (Di Iorio 
and Clark, 2009), while North Atlantic right whales have been observed 
to shift the frequency content of their calls upward while reducing the 
rate of calling in areas of increased anthropogenic noise (Parks et 
al., 2007). In some cases, animals may cease or reduce sound production 
during production of aversive signals (Bowles et al., 1994; Thode et 
al., 2020; Cerchio et al., 2014; McDonald et al., 1995). Blackwell et 
al. (2015) showed that whales increased calling rates as soon as airgun 
signals were detectable before ultimately decreasing calling rates at 
higher received levels.
    Sound can disrupt behavior through masking, or interfering with, an 
animal's ability to detect, recognize, or discriminate between acoustic 
signals of interest (e.g., those used for intraspecific communication 
and social interactions, prey detection, predator avoidance, or 
navigation) (Richardson et al., 1995; Erbe and Farmer, 2000; Tyack, 
2000; Erbe et al., 2016). Masking occurs when the receipt of a sound is 
interfered with

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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 
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, the 
detection of frequencies above those of the masking stimulus decreases. 
This principle is expected to apply to marine mammals as well because 
of common biomechanical cochlear properties across taxa.
    Therefore, when the coincident (masking) sound is man-made, it may 
be considered harassment when disrupting behavioral patterns. It is 
important to distinguish TTS and PTS, which persist after the sound 
exposure, from masking, which only occurs during the sound exposure. 
Because masking (without resulting in threshold shift) is not 
associated with abnormal physiological function, it is not considered a 
physiological effect, but rather a potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009; Matthews, 2017) and may result in energetic or 
other costs as animals change their vocalization behavior (e.g., Miller 
et al., 2000; Foote et al., 2004; Parks et al., 2007; Di Iorio and 
Clark, 2009; Holt et al., 2009). Masking can be reduced in situations 
where the signal and noise come from different directions (Richardson 
et al., 1995), through amplitude modulation of the signal, or through 
other compensatory behaviors (Houser and Moore, 2014). Masking can be 
tested directly in captive species (e.g., Erbe, 2008), but in wild 
populations it must be either modeled or inferred from evidence of 
masking compensation. There are few studies addressing real-world 
masking sounds likely to be experienced by marine mammals in the wild 
(e.g., Branstetter et al., 2013; Cholewiak et al., 2018).
    The echolocation calls of toothed whales are subject to masking by 
high-frequency sound. Human data indicate low-frequency sound can mask 
high-frequency sounds (i.e., upward masking). Studies on captive 
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species 
may use various processes to reduce masking effects (e.g., adjustments 
in echolocation call intensity or frequency as a function of background 
noise conditions). There is also evidence that the directional hearing 
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A 
study by Nachtigall and Supin (2008) showed that false killer whales 
adjust their hearing to compensate for ambient sounds and the intensity 
of returning echolocation signals.
    Impacts on signal detection, measured by masked detection 
thresholds, are not the only important factors to address when 
considering the potential effects of masking. As marine mammals use 
sound to recognize conspecifics, prey, predators, or other biologically 
significant sources (Branstetter et al., 2016), it is also important to 
understand the impacts of masked recognition thresholds (often called 
``informational masking''). Branstetter et al. (2016) measured masked 
recognition thresholds for whistle-like sounds of bottlenose dolphins 
and observed that they are approximately 4 dB above detection 
thresholds (energetic masking) for the same signals. Reduced ability to 
recognize a conspecific call or the acoustic signature of a predator 
could have severe negative impacts. Branstetter et al. (2016) observed 
that if ``quality communication'' is set at 90 percent recognition the 
output of communication space models (which are based on 50 percent 
detection) would likely result in a significant decrease in 
communication range.
    As marine mammals use sound to recognize predators (Allen et al., 
2014; Cummings and Thompson, 1971; Cur[eacute] et al., 2015; Fish and 
Vania, 1971), the presence of masking noise may also prevent marine 
mammals from responding to acoustic cues produced by their predators, 
particularly if it occurs in the same frequency band. For example, 
harbor seals that reside in the coastal waters off British Columbia are 
frequently targeted by mammal-eating killer whales. The seals 
acoustically discriminate between the calls of mammal-eating and fish-
eating killer whales (Deecke et al., 2002), a capability that should 
increase survivorship while reducing the energy required to attend to 
all killer whale calls. Similarly, sperm whales (Cur[eacute] et al., 
2016; Isojunno et al., 2016), long-finned pilot whales (Visser et al., 
2016), and humpback whales (Cur[eacute] et al., 2015) changed their 
behavior in response to killer whale vocalization playbacks; these 
findings indicate that some recognition of predator cues could be 
missed if the killer whale vocalizations were masked. The potential 
effects of masked predator acoustic cues depend on the duration of the 
masking noise and the likelihood of a marine mammal encountering a 
predator during the time that detection and recognition of predator 
cues are impeded.
    Redundancy and context can also facilitate detection of weak 
signals. These phenomena may help marine mammals detect weak sounds in 
the presence of natural or manmade noise. Most masking studies in 
marine mammals present the test signal and the masking noise from the 
same direction. The dominant background noise may be highly directional 
if it comes from a particular anthropogenic source such as a ship or 
industrial site. Directional hearing may significantly reduce the 
masking effects of these sounds by improving the effective signal-to-
noise ratio.
    Masking affects both senders and receivers of acoustic signals and, 
at higher levels and longer duration, can potentially have long-term 
chronic effects on marine mammals at the population level as well as at 
the individual level. Low-frequency ambient sound levels have increased 
by as much as 20 dB (more than three times

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in terms of sound pressure level (SPL)) in the world's ocean from pre-
industrial periods, with most of the increase from distant commercial 
shipping (Hildebrand, 2009; Cholewiak et al., 2018). All anthropogenic 
sound sources, but especially chronic and lower-frequency signals 
(e.g., from commercial vessel traffic), contribute to elevated ambient 
sound levels, thus intensifying masking.
    In addition to making it more difficult for animals to perceive and 
recognize acoustic cues in their environment, anthropogenic sound 
presents separate challenges for animals that are vocalizing. When they 
vocalize, animals are aware of environmental conditions that affect the 
``active space'' (or communication space) of their vocalizations, which 
is the maximum area within which their vocalizations can be detected 
before it drops to the level of ambient noise (Brenowitz, 2004; Brumm 
et al., 2004; Lohr et al., 2003). Animals are also aware of 
environmental conditions that affect whether listeners can discriminate 
and recognize their vocalizations from other sounds, which is more 
important than simply detecting that a vocalization is occurring 
(Brenowitz, 1982; Brumm et al., 2004; Dooling, 2004; Marten and Marler, 
1977; Patricelli and Blickley, 2006). Most species that vocalize have 
evolved with an ability to adjust their vocalizations to increase the 
signal-to-noise ratio, active space, and recognizability/
distinguishability of their vocalizations in the face of temporary 
changes in background noise (Brumm et al., 2004; Patricelli and 
Blickley, 2006). Vocalizing animals can adjust their vocalization 
characteristics such as the frequency structure, amplitude, temporal 
structure, and temporal delivery (repetition rate), or ceasing to 
vocalize.
    Many animals will combine several of these strategies to compensate 
for high levels of background noise. Anthropogenic sounds that reduce 
the signal-to-noise ratio of animal vocalizations, increase the masked 
auditory thresholds of animals listening for such vocalizations, or 
reduce the active space of an animal's vocalizations impair 
communication between animals. Most animals that vocalize have evolved 
strategies to compensate for the effects of short-term or temporary 
increases in background or ambient noise on their songs or calls. 
Although the fitness consequences of these vocal adjustments are not 
directly known in all instances, like most other trade-offs animals 
must make, some of these strategies likely come at a cost (Patricelli 
and Blickley, 2006; Noren et al., 2017; Noren et al., 2020). Shifting 
songs and calls to higher frequencies may also impose energetic costs 
(Lambrechts, 1996).
    Marine mammals are also known to make vocal changes in response to 
anthropogenic noise. In cetaceans, vocalization changes have been 
reported from exposure to anthropogenic noise sources such as sonar, 
vessel noise, and seismic surveying (e.g., Gordon et al., 2003; Di 
Iorio and Clark, 2009; Hatch et al., 2012; Holt et al., 2009; 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 1 to 40 kHz band and reported 
that the whales increased their call source levels by 1-dB SPL for 
every 1-dB SPL increase in background noise level. Similarly, another 
study on St. Lawrence River belugas reported a similar rate of increase 
in vocalization activity in response to passing vessels (Scheifele et 
al., 2005). Di Iorio and Clark (2009) showed that blue whale calling 
rates vary in association with seismic sparker survey activity, with 
whales calling more on days with surveys than on days without surveys. 
They suggested that the whales called more during seismic survey 
periods as a way to compensate for the elevated noise conditions.
    In some cases, these vocal changes may have fitness consequences, 
such as an increase in metabolic rates and oxygen consumption, as 
observed in bottlenose dolphins when increasing their call amplitude 
(Holt et al., 2015). A switch from vocal communication to physical, 
surface-generated sounds such as pectoral fin slapping or breaching was 
observed for humpback whales in the presence of increasing natural 
background noise levels, indicating that adaptations to masking may 
also move beyond vocal modifications (Dunlop et al., 2010).
    While these changes all represent possible tactics by the sound-
producing animal to reduce the impact of masking, the receiving animal 
can also reduce masking by using active listening strategies such as 
orienting to the sound source, moving to a quieter location, or 
reducing self-noise from hydrodynamic flow by remaining still. The 
temporal structure of noise (e.g., amplitude modulation) may also 
provide a considerable release from masking through comodulation 
masking release (a reduction of masking that occurs when broadband 
noise, with a frequency spectrum wider than an animal's auditory filter 
bandwidth at the frequency of interest, is amplitude modulated) 
(Branstetter and Finneran, 2008; Branstetter et al., 2013). Signal type 
(e.g., whistles, burst-pulse, sonar clicks) and spectral 
characteristics (e.g., frequency modulated with harmonics) may further 
influence masked detection thresholds (Branstetter et al., 2016; 
Cunningham et al., 2014).
    Masking is more likely to occur in the presence of broadband, 
relatively continuous noise sources, such as vessels. Several studies 
have shown decreases in marine mammal communication space and changes 
in behavior as a result of the presence of vessel noise. For example, 
right whales were observed to shift the frequency content of their 
calls upward while reducing the rate of calling in areas of increased 
anthropogenic noise (Parks et al., 2007) as well as increasing the 
amplitude (intensity) of their calls (Parks, 2009; 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 (e.g., Holt et al., 
2009; 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

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is an intermittent sound and would not be continuous throughout the 
day.
Habituation and Sensitization
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance having a neutral or positive outcome (Bejder et al., 
2009). The opposite process is sensitization, when an unpleasant 
experience leads to subsequent responses, often in the form of 
avoidance, at a lower level of exposure.
    Both habituation and sensitization require an ongoing learning 
process. As noted, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; National Research Council (NRC), 2003; Wartzok et al., 2003; 
Southall et al., 2019b). Controlled experiments with captive marine 
mammals have shown pronounced behavioral reactions, including avoidance 
of loud sound sources (e.g., Ridgway et al., 1997; Finneran et al., 
2003; Houser et al., 2013a; Houser et al., 2013b; Kastelein et al., 
2018). Observed responses of wild marine mammals to loud impulsive 
sound sources (typically airguns or acoustic harassment devices) have 
been varied but often consist of avoidance behavior or other behavioral 
changes suggesting discomfort (Morton and Symonds, 2002; Richardson et 
al., 1995; Nowacek et al., 2007; Tougaard et al., 2009; Brandt et al., 
2011; Brandt et al., 2012; D[auml]hne et al., 2013; Brandt et al., 
2014; Russell et al., 2016; Brandt et al., 2018).
    Stone (2015) reported data from at-sea observations during 1,196 
airgun surveys from 1994 to 2010. When large arrays of airguns 
(considered to be 500 cubic inches (in\3\) or more) were firing, 
lateral displacement, more localized avoidance, or other changes in 
behavior were evident for most odontocetes. However, significant 
responses to large arrays were found only for the minke whale and fin 
whale. Behavioral responses observed included changes in swimming or 
surfacing behavior with indications that cetaceans remained near the 
water surface at these times. Behavioral observations of gray whales 
during an airgun survey monitored whale movements and respirations 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., Selye, 1950; Moberg and Mench, 
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; NRC, 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.

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Stranding
    The definition for a stranding under title IV of the MMPA is that 
(A) a marine mammal is dead and is (i) on a beach or shore of the 
United States, or (ii) in waters under the jurisdiction of the United 
States (including any navigable waters); or (B) a marine mammal is 
alive and is (i) on a beach or shore of the United States and is unable 
to return to the water, (ii) on a beach or shore of the United States 
and, although able to return to the water, is in need of apparent 
medical attention, or (iii) in the waters under the jurisdiction of the 
United States (including any navigable waters), but is unable to return 
to its natural habitat under its own power or without assistance (16 
U.S.C. 1421h).
    Marine mammal strandings have been linked to a variety of causes, 
such as illness from exposure to infectious agents, biotoxins, or 
parasites; starvation; unusual oceanographic or weather events; or 
anthropogenic causes including fishery interaction, ship strike, 
entrainment, entrapment, sound exposure, or combinations of these 
stressors sustained concurrently or in series. There have been multiple 
events worldwide in which marine mammals (primarily beaked whales, or 
other deep divers) have stranded coincident with relatively nearby 
activities utilizing loud sound sources (primarily military training 
events), and five in which mid-frequency active sonar has been more 
definitively determined to have been a contributing factor.
    There are multiple theories regarding the specific mechanisms 
responsible for marine mammal strandings caused by exposure to loud 
sounds. One primary theme is the behaviorally mediated responses of 
deep-diving species (odontocetes), in which their startled response to 
an acoustic disturbance (1) affects ascent or descent rates, the time 
they stay at depth or the surface, or other regular dive patterns that 
are used to physiologically manage gas formation and absorption within 
their bodies, such that the formation or growth of gas bubbles damages 
tissues or causes other injury, or (2) results in their flight to 
shallow areas, enclosed bays, or other areas considered ``out of 
habitat,'' in which they become disoriented and physiologically 
compromised. For more information on marine mammal stranding events and 
potential causes, please see the Mortality and Stranding section of 
NMFS Proposed Incidental Take Regulations for the Navy's Training and 
Testing Activities in the Hawaii-Southern California Training and 
Testing Study Area (50 CFR part 218, volume 83, No. 123, June 26, 
2018).
    The construction activities proposed by US Wind (i.e., pile 
driving) do not inherently have the potential to result in marine 
mammal strandings. While vessel strikes could kill or injure a marine 
mammals (which may eventually strand), the required mitigation measures 
would reduce the potential for take from these activities to de minimus 
levels (see Proposed Mitigation section for more details). As described 
above, no mortality or serious injury is anticipated or proposed to be 
authorized from any Project activities.
    Of the strandings documented to date worldwide, NMFS is not aware 
of any being attributed to pile driving or to the types of HRG 
equipment proposed for use during the Project. Recently, there has been 
heightened interest in HRG surveys and their potential role in recent 
marine mammals strandings along the U.S. east coast. HRG surveys 
involve the use of certain sources to image the ocean bottom, which are 
very different from seismic airguns used in oil and gas surveys or 
tactical military sonar, in that they produce much smaller impact 
zones. Marine mammals may respond to exposure to these sources by, for 
example, avoiding the immediate area, which is why offshore wind 
developers have authorization to allow for Level B (behavioral) 
harassment, including US Wind. However, because of the combination of 
lower source levels, higher frequency, narrower beam-width (for some 
sources), and other factors, the area within which a marine mammal 
might be expected to be behaviorally disturbed by HRG sources is much 
smaller (by orders of magnitude) than the impact areas for seismic 
airguns or the military sonar with which a small number of marine 
mammal have been causally associated. Specifically, estimated 
harassment zones for HRG surveys are typically less than 200m (such as 
those associated with the Project), while zones for military mid-
frequency active sonar or seismic airgun surveys typically extend for 
several kms ranging up to 10s of km. Further, because of this much 
smaller ensonified area, any marine mammal exposure to HRG sources is 
reasonably expected to be at significantly lower levels and shorter 
duration (associated with less severe responses), and there is no 
evidence suggesting, or reason to speculate, that marine mammals 
exposed to HRG survey noise are likely to be injured, much less strand, 
as a result. Last, all but one of the small number of marine mammal 
stranding events that have been causally associated with exposure to 
loud sound sources have been deep-diving toothed whale species (not 
mysticetes), which are known to respond differently to loud sounds.

Potential Effects of Disturbance on Marine Mammal Fitness

    The different ways that marine mammals respond to sound are 
sometimes indicators of the ultimate effect that exposure to a given 
stimulus will have on the well-being (survival, reproduction, etc.) of 
an animal. There are numerous data relating the exposure of terrestrial 
mammals from sound to effects on reproduction or survival, and data for 
marine mammals continues to grow. Several authors have reported that 
disturbance stimuli may cause animals to abandon nesting and foraging 
sites (Sutherland and Crockford, 1993); may cause animals to increase 
their activity levels and suffer premature deaths or reduced 
reproductive success when their energy expenditures exceed their energy 
budgets (Daan et al., 1996; Feare, 1976; Mullner et al., 2004); or may 
cause animals to experience higher predation rates when they adopt 
risk-prone foraging or migratory strategies (Frid and Dill, 2002). Each 
of these studies addressed the consequences of animals shifting from 
one behavioral state (e.g., resting or foraging) to another behavioral 
state (e.g., avoidance or escape behavior) because of human disturbance 
or disturbance stimuli.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
subconsciously (for example, when an animal hears sounds that it 
associates with the approach of a predator) and the shift in attention 
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has 
captured an animal's attention, the animal can respond by ignoring the 
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus 
as a disturbance and respond accordingly, which includes scanning for 
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
    Vigilance is an adaptive behavior that helps animals determine the 
presence or absence of predators, assess their distance from 
conspecifics, or to attend cues from prey (Bednekoff and Lima,

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1998; Treves, 2000). Despite those benefits, however, vigilance has a 
cost of time; when animals focus their attention on specific 
environmental cues, they are not attending to other activities such as 
foraging or resting. These effects have generally not been demonstrated 
for marine mammals, but studies involving fish and terrestrial animals 
have shown that increased vigilance may substantially reduce feeding 
rates (Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002; 
Purser and Radford, 2011). Animals will spend more time being vigilant, 
which may translate to less time foraging or resting, when disturbance 
stimuli approach them more directly, remain at closer distances, have a 
greater group size (e.g., multiple surface vessels), or when they co-
occur with times that an animal perceives increased risk (e.g., when 
they are giving birth or accompanied by a calf).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand while decreasing their caloric intake/energy). In a 
study of northern resident killer whales off Vancouver Island, exposure 
to boat traffic was shown to reduce foraging opportunities and increase 
traveling time (Holt et al., 2021). A simple bioenergetics model was 
applied to show that the reduced foraging opportunities equated to a 
decreased energy intake of 18 percent while the increased traveling 
incurred an increased energy output of 3-4 percent, which suggests that 
a management action based on avoiding interference with foraging might 
be particularly effective.
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hour 
cycle). Behavioral reactions to noise exposure (such as disruption of 
critical life functions, displacement, or avoidance of important 
habitat) are more likely to be significant for fitness if they last 
more than one diel cycle or recur on subsequent days (Southall et al., 
2007). Consequently, a behavioral response lasting less than 1 day and 
not recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). It is important to note the difference between behavioral 
reactions lasting or recurring over multiple days and anthropogenic 
activities lasting or recurring over multiple days. For example, just 
because certain activities last for multiple days does not necessarily 
mean that individual animals will be either exposed to those activity-
related stressors (i.e., sonar) for multiple days or further exposed in 
a manner that would result in sustained multi-day substantive 
behavioral responses. However, special attention is warranted where 
longer-duration activities overlay areas in which animals are known to 
congregate for longer durations for biologically important behaviors.
    There are few studies that directly illustrate the impacts of 
disturbance on marine mammal populations. Lusseau and Bejder (2007) 
present data from three long-term studies illustrating the connections 
between disturbance from whale-watching boats and population-level 
effects in cetaceans. In Shark Bay, Australia, the abundance of 
bottlenose dolphins was compared within adjacent control and tourism 
sites over three consecutive 4.5-year periods of increasing tourism 
levels. Between the second and third time periods, in which tourism 
doubled, dolphin abundance decreased by 15 percent in the tourism area 
and did not change significantly in the control area. In Fiordland, New 
Zealand, two populations (Milford and Doubtful Sounds) of bottlenose 
dolphins with tourism levels that differed by a factor of seven were 
observed and significant increases in traveling time and decreases in 
resting time were documented for both. Consistent short-term avoidance 
strategies were observed in response to tour boats until a threshold of 
disturbance was reached (average of 68 minutes between interactions), 
after which the response switched to a longer-term habitat displacement 
strategy. For one population, tourism only occurred in a part of the 
home range. However, tourism occurred throughout the home range of the 
Doubtful Sound population and once boat traffic increased beyond the 
68-minute threshold (resulting in abandonment of their home range/
preferred habitat), reproductive success drastically decreased 
(increased stillbirths) and abundance decreased significantly (from 67 
to 56 individuals in a short period).
    In order to understand how the effects of activities may or may not 
impact species and stocks of marine mammals, it is necessary to 
understand not only what the likely disturbances are going to be but 
how those disturbances may affect the reproductive success and 
survivorship of individuals, and then how those impacts to individuals 
translate to population-level effects. Following on the earlier work of 
a committee of the U.S. NRC (NRC, 2005), New et al. (2014), in an 
effort termed the Potential Consequences of Disturbance (PCoD), 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 the PCoD general framework was outlined and the relevant 
supporting literature compiled, multiple studies developing state-space 
energetic models for species with extensive long-term monitoring (e.g., 
southern elephant seals, 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 effect. Since New et al. (2014), several 
publications have described models developed to examine the long-term 
effects of environmental or anthropogenic disturbance of foraging on 
various life stages of selected species (e.g., sperm whale, Farmer et 
al., 2018; California sea lion, McHuron et al., 2018; blue whale, 
Pirotta et al., 2018a; humpback whale, Dunlop et al., 2021). These 
models continue to add to refinement of the approaches to the PCoD 
framework. Such models also help identify what data inputs require 
further investigation. Pirotta et al. (2018b) provides a review of the 
PCoD framework with details on each step of the process and approaches 
to applying real data or simulations to achieve each step.
    Despite its simplicity, there are few complete PCoD models 
available for any marine mammal species due to a lack of data available 
to parameterize many of the steps. To date, no PCoD model has

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been fully parameterized with empirical data (Pirotta et al., 2018a) 
due to the fact they are data intensive and logistically challenging to 
complete. Therefore, most complete PCoD models include simulations, 
theoretical modeling, and expert opinion to move through the steps. For 
example, PCoD models have been developed to evaluate the effect of wind 
farm construction on the North Sea harbor porpoise populations (e.g., 
King et al., 2015; Nabe-Nielsen et al., 2018). These models include a 
mix of empirical data, expert elicitation (King et al., 2015) and 
simulations of animals' movements, energetics, and/or survival (New et 
al., 2014; Nabe-Nielsen et al., 2018).
    PCoD models may also be approached in different manners. Dunlop et 
al. (2021) modeled migrating humpback whale mother-calf pairs in 
response to seismic surveys using both a forwards and backwards 
approach. While a typical forwards approach can determine if a stressor 
would have population-level consequences, Dunlop et al. demonstrated 
that working backwards through a PCoD model can be used to assess the 
``worst case'' scenario for an interaction of a target species and 
stressor. This method may be useful for future management goals when 
appropriate data becomes available to fully support the model. In 
another example, harbor porpoise PCoD model investigating the impact of 
seismic surveys on harbor porpoise included an investigation on 
underlying drivers of vulnerability. Harbor porpoise movement and 
foraging were modeled for baseline periods and then for periods with 
seismic surveys as well; the models demonstrated that temporal (i.e., 
seasonal) variation in individual energetics and their link to costs 
associated with disturbances was key in predicting population impacts 
(Gallagher et al., 2021).
    Behavioral change, such as disturbance manifesting in lost foraging 
time, in response to anthropogenic activities is often assumed to 
indicate a biologically significant effect on a population of concern. 
However, as described above, individuals may be able to compensate for 
some types and degrees of shifts in behavior, preserving their health 
and thus their vital rates and population dynamics. For example, New et 
al. (2013) developed a model simulating the complex social, spatial, 
behavioral, and motivational interactions of coastal bottlenose 
dolphins in the Moray Firth, Scotland, to assess the biological 
significance of increased rate of behavioral disruptions caused by 
vessel traffic. Despite a modeled scenario in which vessel traffic 
increased from 70 to 470 vessels a year (a six-fold increase in vessel 
traffic) in response to the construction of a proposed offshore 
renewables' facility, the dolphins' behavioral time budget, spatial 
distribution, motivations, and social structure remain unchanged. 
Similarly, two bottlenose dolphin populations in Australia were also 
modeled over 5 years against a number of disturbances (Reed et al., 
2020), and results indicated that habitat/noise disturbance had little 
overall impact on population abundances in either location, even in the 
most extreme impact scenarios modeled.
    By integrating different sources of data (e.g., controlled exposure 
data, activity monitoring, telemetry tracking, and prey sampling) into 
a theoretical model to predict effects from sonar on a blue whale's 
daily energy intake, Pirotta et al. (2021) found that tagged blue 
whales' activity budgets, lunging rates, and ranging patterns caused 
variability in their predicted cost of disturbance. This method may be 
useful for future management goals when appropriate data becomes 
available to fully support the model. Harbor porpoise movement and 
foraging were modeled for baseline periods and then for periods with 
seismic surveys as well; the models demonstrated that the seasonality 
of the seismic activity was an important predictor of impact (Gallagher 
et al., 2021).
    In their table 1, Keen et al. (2021) summarize the emerging themes 
in PCoD models that should be considered when assessing the likelihood 
and duration of exposure and the sensitivity of a population to 
disturbance (see table 1 from Keen et al., 2021, below). The themes are 
categorized by life history traits (movement ecology, life history 
strategy, body size, and pace of life), disturbance source 
characteristics (overlap with biologically important areas, duration 
and frequency, and nature and context), and environmental conditions 
(natural variability in prey availability and climate change). Keen et 
al. (2021) then summarize how each of these features influence an 
assessment, noting, for example, that individual animals with small 
home ranges have a higher likelihood of prolonged or year-round 
exposure, that the effect of disturbance is strongly influenced by 
whether it overlaps with biologically important habitats when 
individuals are present, and that continuous disruption will have a 
greater impact than intermittent disruption.
    Nearly all PCoD studies and experts agree that infrequent exposures 
of a single day or less are unlikely to impact individual fitness, let 
alone lead to population level effects (Booth et al., 2016; Booth et 
al., 2017; Christiansen and Lusseau, 2015; Farmer et al., 2018; Wilson 
et al., 2020; Harwood and Booth, 2016; King et al., 2015; McHuron et 
al., 2018; National Academies of Sciences, Engineering, and Medicine 
(NAS), 2017; New et al., 2014; Pirotta et al., 2018a; Southall et al., 
2007; Villegas-Amtmann et al., 2015). As described through this 
proposed rule, NMFS expects that any behavioral disturbance that would 
occur due to animals being exposed to construction activity would be of 
a relatively short duration, with behavior returning to a baseline 
state shortly after the acoustic stimuli ceases or the animal moves far 
enough away from the source. Given this, and NMFS' evaluation of the 
available PCoD studies, and the required mitigation discussed later, 
any such behavioral disturbance resulting from US Wind's activities is 
not expected to impact individual animals' health or have effects on 
individual animals' survival or reproduction, thus no detrimental 
impacts at the population level are anticipated. Marine mammals may 
temporarily avoid the immediate area but are not expected to 
permanently abandon the area or their migratory or foraging behavior. 
Impacts to breeding, feeding, sheltering, resting, or migration are not 
expected nor are shifts in habitat use, distribution, or foraging 
success.

Potential Effects From Vessel Strike

    Vessel collisions with marine mammals, also referred to as vessel 
strikes or ship strikes, can result in death or serious injury of the 
animal. Wounds resulting from ship strike may include massive trauma, 
hemorrhaging, broken bones, or propeller lacerations (Knowlton and 
Kraus, 2001). An animal at the surface could be struck directly by a 
vessel, a surfacing animal could hit the bottom of a vessel, or an 
animal just below the surface could be cut by a vessel's propeller. 
Superficial strikes may not kill or result in the death of the animal. 
Lethal interactions are typically associated with large whales, which 
are occasionally found draped across the bulbous bow of large 
commercial ships upon arrival in port. Although smaller cetaceans are 
more maneuverable in relation to large vessels than are large whales, 
they may also be susceptible to strike. The severity of injuries 
typically depends on the size and speed of the vessel (Knowlton and 
Kraus, 2001; Laist et al., 2001; Vanderlaan and Taggart, 2007; Conn and 
Silber, 2013). Impact forces increase with speed, as does the 
probability of a strike at a given distance (Silber et al., 2010; Gende 
et al., 2011).

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    The most vulnerable marine mammals are those that spend extended 
periods of time at the surface in order to restore oxygen levels within 
their tissues after deep dives (e.g., the sperm whale). In addition, 
some baleen whales seem generally unresponsive to vessel sound, making 
them more susceptible to vessel collisions (Nowacek et al., 2004). 
These species are primarily large, slow-moving whales. Marine mammal 
responses to vessels may include avoidance and changes in dive pattern 
(NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike occurs and, if so, whether it results in 
injury, serious injury, or mortality (Knowlton and Kraus, 2001; Laist 
et al., 2001; Jensen and Silber, 2003; Pace and Silber, 2005; 
Vanderlaan and Taggart, 2007; Conn and Silber, 2013). In assessing 
records in which vessel speed was known, Laist et al. (2001) found a 
direct relationship between the occurrence of a whale strike and the 
speed of the vessel involved in the collision. The authors concluded 
that most deaths occurred when a vessel was traveling in excess of 13 
kn.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58 cases. Of 
these 58 cases, 39 (or 67 percent) resulted in serious injury or death 
(19 of those resulted in serious injury as determined by blood in the 
water, propeller gashes or severed tailstock, and fractured skull, jaw, 
vertebrae, hemorrhaging, massive bruising, or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 kn. The 
majority (79 percent) of these strikes occurred at speeds of 13 kn or 
greater. The average speed that resulted in serious injury or death was 
18.6 kn. Pace and Silber (2005) found that the probability of death or 
serious injury increased rapidly with increasing vessel speed. 
Specifically, the predicted probability of serious injury or death 
increased from 45 to 75 percent as vessel speed increased from 10 to 14 
kn and exceeded 90 percent at 17 kn. Higher speeds during collisions 
result in greater force of impact and also appear to increase the 
chance of severe injuries or death. While modeling studies have 
suggested that hydrodynamic forces pulling whales toward the vessel 
hull increase with increasing speed (Clyne, 1999; Knowlton et al., 
1995), this is inconsistent with Silber et al. (2010), which 
demonstrated that there is no such relationship (i.e., hydrodynamic 
forces are independent of speed).
    In a separate study, Vanderlaan and Taggart (2007) analyzed the 
probability of lethal mortality of large whales at a given speed, 
showing that the greatest rate of change in the probability of a lethal 
injury to a large whale as a function of vessel speed occurs between 
8.6 and 15 kn. The chances of a lethal injury decline from 
approximately 80 percent at 15 kn to approximately 20 percent at 8.6 
kn. At speeds below 11.8 kn, the chances of lethal injury drop below 50 
percent, while the probability asymptotically increases toward 100 
percent above 15 kn.
    The Jensen and Silber (2003) report notes that the Large Whale Ship 
Strike Database represents a minimum number of collisions, because the 
vast majority probably goes undetected or unreported. In contrast, the 
Project's personnel are likely to detect any strike that does occur 
because of the required personnel training and lookouts, along with the 
inclusion of Protected Species Observers (as described in the Proposed 
Mitigation section), and they are required to report all ship strikes 
involving marine mammals.
    There are no known vessel strikes of marine mammals by any offshore 
wind energy vessel in the United States. Given the extensive mitigation 
and monitoring measures (see the Proposed Mitigation and Proposed 
Monitoring and Reporting section) that would be required of US Wind, 
NMFS believes that a vessel strike is not likely to occur.

Potential Effects to Marine Mammal Habitat

    US Wind's proposed activities could potentially affect marine 
mammal habitat through the introduction of impacts to the prey species 
of marine mammals (through noise, oceanographic processes, or reef 
effects), acoustic habitat (sound in the water column), water quality, 
and biologically important habitat for marine mammals.
Effects on Prey
    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., crustaceans, 
cephalopods, fish, and zooplankton). Marine mammal prey varies by 
species, season, and location and, for some, is not well documented. 
Here, we describe studies regarding the effects of noise on known 
marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay, 
2009). The most likely effects on fishes exposed to loud, intermittent, 
low-frequency sounds are behavioral responses (i.e., flight or 
avoidance). Short duration, sharp sounds (such as pile driving or 
airguns) can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to acoustic sources depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. Key 
impacts to fishes may include behavioral responses, hearing damage, 
barotrauma (pressure-related injuries), and mortality. While it is 
clear that the behavioral responses of individual prey, such as 
displacement or other changes in distribution, can have direct impacts 
on the foraging success of marine mammals, the effects on marine 
mammals of individual prey that experience hearing damage, barotrauma, 
or mortality is less clear, though obviously population scale impacts 
that meaningfully reduce the amount of prey available could have more 
serious impacts.
    Fishes, like other vertebrates, have a variety of different sensory 
systems to glean information from ocean around them (Astrup and Mohl, 
1993; Astrup, 1999; Braun and Grande, 2008; Carroll et al., 2017; 
Hawkins and Johnstone, 1978; Ladich and Popper, 2004; Ladich and 
Schulz-Mirbach, 2016; Mann, 2016; Nedwell et al., 2004; Popper et al., 
2003; Popper et al., 2005). Depending on their hearing anatomy and 
peripheral sensory structures, which vary among species, fishes hear 
sounds using pressure and particle motion sensitivity capabilities and 
detect the motion of surrounding water (Fay et al., 2008) (terrestrial 
vertebrates generally only detect pressure). Most marine fishes 
primarily detect particle motion using the inner ear and lateral line 
system while some fishes possess additional morphological adaptations 
or specializations that can enhance their sensitivity to sound 
pressure, such as a gas-filled swim bladder (Braun and Grande, 2008; 
Popper and Fay, 2011).
    Hearing capabilities vary considerably between different fish 
species with data only available for just over 100 species out of the 
34,000 marine and freshwater fish species (Eschmeyer and Fong, 2016). 
In order to better understand acoustic impacts on fishes, fish hearing 
groups are defined by species that possess a similar continuum of 
anatomical features, which result in varying degrees of hearing 
sensitivity

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(Popper and Hastings, 2009a). There are four hearing groups defined for 
all fish species (modified from Popper et al., 2014) within this 
analysis, and they include: fishes without a swim bladder (e.g., 
flatfish, sharks, rays, etc.); fishes with a swim bladder not involved 
in hearing (e.g., salmon, cod, pollock, etc.); fishes with a swim 
bladder involved in hearing (e.g., sardines, anchovy, herring, etc.); 
and fishes with a swim bladder involved in hearing and high-frequency 
hearing (e.g., shad and menhaden). Most marine mammal fish prey species 
would not be likely to perceive or hear mid- or high-frequency sonars. 
While hearing studies have not been done on sardines and northern 
anchovies, it would not be unexpected for them to have hearing 
similarities to Pacific herring (up to 2-5 kHz) (Mann et al., 2005). 
Currently, less data are available to estimate the range of best 
sensitivity for fishes without a swim bladder.
    In terms of physiology, multiple scientific studies have documented 
a lack of mortality or physiological effects to fish from exposure to 
low- and mid-frequency sonar and other sounds (Halvorsen et al., 2012a; 
J[oslash]rgensen et al., 2005; Juanes et al., 2017; Kane et al., 2010; 
Kvadsheim and Sevaldsen, 2005; Popper et al., 2007; Popper et al., 
2016; Watwood et al., 2016). Techer et al. (2017) exposed carp in 
floating cages for up to 30 days to low-power 23 and 46 kHz source 
without any significant physiological response. Other studies have 
documented either a lack of TTS in species whose hearing range cannot 
perceive sonar (such as Navy sonar), or for those species that could 
perceive sonar-like signals, any TTS experienced would be recoverable 
(Halvorsen et al., 2012a; Ladich and Fay, 2013; Popper and Hastings, 
2009a, 2009b; Popper et al., 2014; Smith, 2016). Only fishes that have 
specializations that enable them to hear sounds above about 2,500 Hz 
(2.5 kHz), such as herring (Halvorsen et al., 2012a; Mann et al., 2005; 
Mann, 2016; Popper et al., 2014), would have the potential to receive 
TTS or exhibit behavioral responses from exposure to mid-frequency 
sonar. In addition, any sonar induced TTS to fish whose hearing range 
could perceive sonar would only occur in the narrow spectrum of the 
source (e.g., 3.5 kHz) compared to the fish's total hearing range 
(e.g., 0.01 kHz to 5 kHz).
    In terms of behavioral responses, Juanes et al. (2017) discuss the 
potential for negative impacts from anthropogenic noise on fish, but 
the author's focus was on broader based sounds, such as ship and boat 
noise sources. Watwood et al. (2016) also documented no behavioral 
responses by reef fish after exposure to mid-frequency active sonar. 
Doksaeter et al. (2009; 2012) reported no behavioral responses to mid-
frequency sonar (such as naval sonar) by Atlantic herring; 
specifically, no escape reactions (vertically or horizontally) were 
observed in free swimming herring exposed to mid-frequency sonar 
transmissions. Based on these results (Doksaeter et al., 2009; 
Doksaeter et al., 2012; Sivle et al., 2012), Sivle et al. (2014) 
created a model in order to report on the possible population-level 
effects on Atlantic herring from active sonar. The authors concluded 
that the use of sonar poses little risk to populations of herring 
regardless of season, even when the herring populations are aggregated 
and directly exposed to sonar. Finally, Bruintjes et al. (2016) 
commented that fish exposed to any short-term noise within their 
hearing range might initially startle but would quickly return to 
normal behavior.
    Pile driving noise during construction is of particular concern as 
the very high sound pressure levels could potentially prevent fish from 
reaching breeding or spawning sites, finding food, and acoustically 
locating mates. A playback study in West Scotland revealed that there 
was a significant movement response to the pile driving stimulus in 
both species at relatively low received sound pressure levels (sole: 
144-156 dB re 1[mu]Pa Peak; cod: 140-161 dB re 1 [mu]Pa Peak, particle 
motion between 6.51 * 10\3\ and 8.62 * 10\4\ m/s\2\ peak) (Mueller-
Blenkle et al., 2010). The swimming speed of sole increased 
significantly during the playback of construction noise when compared 
to the playbacks of before and after construction. While not 
statistically significant, cod also displayed a similar behavioral 
response during before, during, and after construction playbacks. 
However, cod demonstrated a specific and significant freezing response 
at the onset and cessation of the playback recording. In both species, 
indications were present displaying directional movements away from the 
playback source. During wind farm construction in the eastern Taiwan 
Strait, Type 1 soniferous fish chorusing showed a relatively lower 
intensity and longer duration while Type 2 chorusing exhibited higher 
intensity and no changes in its duration. Deviation from regular fish 
vocalization patterns may affect fish reproductive success, cause 
migration, augmented predation, or physiological alterations.
    Occasional behavioral reactions to activities that produce 
underwater noise sources are unlikely to cause long-term consequences 
for individual fish or populations. The most likely impact to fish from 
impact and vibratory pile driving activities at the project areas would 
be temporary behavioral avoidance of the area. Any behavioral avoidance 
by fish of the disturbed area would still leave significantly large 
areas of fish and marine mammal foraging habitat in the nearby 
vicinity. The duration of fish avoidance of an area after pile driving 
stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. In general, impacts to marine 
mammal prey species are expected to be minor and temporary due to the 
expected short daily duration of individual pile driving events and the 
relatively small areas being affected.
    SPLs of sufficient strength have been known to cause fish auditory 
impairment, injury, and mortality. Popper et al. (2014) found that fish 
with or without air bladders could experience TTS at 186 dB 
SEL<INF>cum</INF>. Mortality could occur for fish without swim bladders 
at >216 dB SEL<INF>cum</INF>. Those with swim bladders or at the egg or 
larvae life stage, mortality was possible at >203 dB SEL<INF>cum</INF>. 
Other studies found that 203 dB SEL<INF>cum</INF> or above caused a 
physiological response in other fish species (Casper et al., 2012; 
Halvorsen et al., 2012a; Halvorsen et al., 2012b; Casper et al., 2013a; 
Casper et al., 2013b). However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours 
for one species. Impacts would be most severe when the individual fish 
is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013a).
    As described in the Proposed Mitigation section below, US Wind 
would utilize a sound attenuation device which would reduce potential 
for injury to marine mammal prey. Other fish that experience hearing 
loss as a result of exposure to impulsive sound sources may have a 
reduced ability to detect relevant sounds such as predators, prey, or 
social vocalizations. However, PTS has not been known to occur in 
fishes and any hearing loss in fish may be as temporary as the 
timeframe required to repair or replace the sensory cells that were 
damaged or destroyed (Popper et al., 2005; Popper et al., 2014; Smith, 
2006). It is not known if damage to auditory nerve fibers could

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occur, and if so, whether fibers would recover during this process. In 
addition, most acoustic effects, if any, are expected to be short-term 
and localized. Long-term consequences for fish populations, including 
key prey species within the project area, would not be expected.
    Required soft-starts would allow prey and marine mammals to move 
away from the source prior to any noise levels that may physically 
injure prey and the use of the noise attenuation devices would reduce 
noise levels to the degree any mortality or injury of prey is also 
minimized. Use of bubble curtains, in addition to reducing impacts to 
marine mammals, for example, is a key mitigation measure in reducing 
injury and mortality of ESA-listed salmon on the U.S. west coast. 
However, we recognize some mortality, physical injury and hearing 
impairment in marine mammal prey may occur, but we anticipate the 
amount of prey impacted in this manner is minimal compared to overall 
availability. Any behavioral responses to pile driving by marine mammal 
prey are expected to be brief. We expect that other impacts, such as 
stress or masking, would occur in fish that serve as marine mammals 
prey (Popper et al., 2019); however, those impacts would be limited to 
the duration of impact pile driving, and, if prey were to move out the 
area in response to noise, these impacts would be minimized.
    In addition to fish, prey sources such as marine invertebrates 
could potentially be impacted by noise stressors as a result of the 
proposed activities. However, most marine invertebrates' ability to 
sense sounds is limited. Invertebrates appear to be able to detect 
sounds (Pumphrey, 1950; Frings and Frings, 1967) and are most sensitive 
to low-frequency sounds (Packard et al., 1990; Budelmann and 
Williamson, 1994; Lovell et al., 2005; Mooney et al., 2010). Data on 
response of invertebrates such as squid, another marine mammal prey 
species, to anthropogenic sound is more limited (de Soto, 2016; Sole et 
al., 2017). Data suggest that cephalopods are capable of sensing the 
particle motion of sounds and detect low frequencies up to 1-1.5 kHz, 
depending on the species, and so are likely to detect airgun noise 
(Kaifu et al., 2008; Hu et al., 2009; Mooney et al., 2010; Samson et 
al., 2014). Sole et al. (2017) reported physiological injuries to 
cuttlefish in cages placed at-sea when exposed during a controlled 
exposure experiment to low-frequency sources (315 Hz, 139 to 142 dB re 
1 [mu]Pa\2\; 400 Hz, 139 to 141 dB re 1 [mu]Pa\2\). Fewtrell and 
McCauley (2012) reported squids maintained in cages displayed startle 
responses and behavioral changes when exposed to seismic airgun sonar 
(136-162 re 1 [mu]Pa\2\[middot]s). Jones et al. (2020) found that when 
squid (Doryteuthis pealeii) were exposed to impulse pile driving noise, 
body pattern changes, inking, jetting, and startle responses were 
observed and nearly all squid exhibited at least one response. However, 
these responses occurred primarily during the first eight impulses and 
diminished quickly, indicating potential rapid, short-term habituation.
    Cephalopods have a specialized sensory organ inside the head called 
a statocyst that may help an animal determine its position in space 
(orientation) and maintain balance (Budelmann, 1992). Packard et al. 
(1990) showed that cephalopods were sensitive to particle motion, not 
sound pressure, and Mooney et al. (2010) demonstrated that squid 
statocysts act as an accelerometer through which particle motion of the 
sound field can be detected. Auditory injuries (lesions occurring on 
the statocyst sensory hair cells) have been reported upon controlled 
exposure to low-frequency sounds, suggesting that cephalopods are 
particularly sensitive to low-frequency sound (Andre et al., 2011; Sole 
et al., 2013). Behavioral responses, such as inking and jetting, have 
also been reported upon exposure to low-frequency sound (McCauley et 
al., 2000; Samson et al., 2014). Squids, like most fish species, are 
likely more sensitive to low-frequency sounds and may not perceive mid- 
and high-frequency sonars.
    With regard to potential impacts on zooplankton, McCauley et al. 
(2017) found that exposure to airgun noise resulted in significant 
depletion for more than half the taxa present and that there were two 
to three times more dead zooplankton after airgun exposure compared 
with controls for all taxa, within 1 km of the airguns. However, the 
authors also stated that in order to have significant impacts on r-
selected species (i.e., those with high growth rates and that produce 
many offspring) such as plankton, the spatial or temporal scale of 
impact must be large in comparison with the ecosystem concerned, and it 
is possible that the findings reflect avoidance by zooplankton rather 
than mortality (McCauley et al., 2017). In addition, the results of 
this study are inconsistent with a large body of research that 
generally finds limited spatial and temporal impacts to zooplankton as 
a result of exposure to airgun noise (e.g., Dalen and Knutsen, 1987; 
Payne, 2004; Stanley et al., 2011). Most prior research on this topic, 
which has focused on relatively small spatial scales, has showed 
minimal effects (e.g., Kostyuchenko, 1973; Booman et al., 1996; 
S[aelig]tre and Ona, 1996; Pearson et al., 1994; Bolle et al., 2012).
    A modeling exercise was conducted as a follow-up to the McCauley et 
al. (2017) study (as recommended by McCauley et al.), in order to 
assess the potential for impacts on ocean ecosystem dynamics and 
zooplankton population dynamics (Richardson et al., 2017). Richardson 
et al. (2017) found that a full-scale airgun survey would impact 
copepod abundance within the survey area, but that effects at a 
regional scale were minimal (2 percent decline in abundance within 150 
km of the survey area and effects not discernible over the full 
region). The authors also found that recovery within the survey area 
would be relatively quick (3 days following survey completion) and 
suggest that the quick recovery was due to the fast growth rates of 
zooplankton, and the dispersal and mixing of zooplankton from both 
inside and outside of the impacted region. The authors also suggest 
that surveys in areas with more dynamic ocean circulation in comparison 
with the study region and/or with deeper waters (i.e., typical offshore 
wind locations) would have less net impact on zooplankton.
    Notably, a recently described study produced results inconsistent 
with those of McCauley et al. (2017). Researchers conducted a field and 
laboratory study to assess if exposure to airgun noise affects 
mortality, predator escape response, or gene expression of the copepod 
Calanus finmarchicus (Fields et al., 2019). Immediate mortality of 
copepods was significantly higher, relative to controls, at distances 
of 5 m or less from the airguns. Mortality 1 week after the airgun 
blast was significantly higher in the copepods placed 10 m from the 
airgun but was not significantly different from the controls at a 
distance of 20 m from the airgun. The increase in mortality, relative 
to controls, did not exceed 30 percent at any distance from the airgun. 
Moreover, the authors caution that even this higher mortality in the 
immediate vicinity of the airguns may be more pronounced than what 
would be observed in free-swimming animals due to increased flow speed 
of fluid inside bags containing the experimental animals. There were no 
sub-lethal effects on the escape performance, or the sensory threshold 
needed to initiate an escape response, at any of the distances from the 
airgun that were tested. Whereas McCauley et al. (2017) reported an SEL

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of 156 dB at a range of 509-658 m, with zooplankton mortality observed 
at that range, Fields et al. (2019) reported an SEL of 186 dB at a 
range of 25 m, with no reported mortality at that distance.
    The presence of large numbers of turbines has been shown to impact 
meso- and sub-meso-scale water column circulation, which can affect the 
density, distribution, and energy content of zooplankton and thereby, 
their availability as marine mammal prey. Topside, atmospheric wakes 
result in wind speed reductions influencing upwelling and downwelling 
in the ocean while underwater structures such as WTG and OSS 
foundations may cause turbulent current wakes, which impact 
circulation, stratification, mixing, and sediment resuspension (Daewel 
et al., 2022). Overall, the presence of structures such as wind 
turbines is, in general, likely to result in certain oceanographic 
effects in the marine environment and may alter marine mammal prey, 
such as aggregations and distribution of zooplankton through changing 
the strength of tidal currents and associated fronts, changes in 
stratification, primary production, the degree of mixing, and 
stratification in the water column (Chen et al., 2021; Johnson et al., 
2021; Christiansen et al., 2022; Dorrell et al., 2022).
    US Wind intends to install up to 114 WTG and 4 OSS foundations, 
with turbine operations commencing in 2025 and all turbines being 
operational in 2027. As described above, there is scientific 
uncertainty around the scale of oceanographic impacts (meters to 
kilometers) associated with turbine operation. The Project is located 
offshore of Maryland along the mid-Atlantic Bight, and the project area 
does not include key foraging grounds for marine mammals with 
planktonic diets (e.g., North Atlantic right whale), as all known prime 
foraging habitat is located much further north, off southern New 
England and north into Canada. This foraging area is approximately 
544.1 km (338.1 mi) north of the project area, and it would be highly 
unlikely for this foraging area to be influenced by activities related 
to the proposed Project.
    Although the project area does not provide high-quality foraging 
habitat for plankton-feeding marine mammals, such as North Atlantic 
right whales, coastal Maryland may provide seasonal high-quality 
foraging habitat for piscivorous marine mammals, such as humpback 
whales. Generally speaking, and depending on the extent, impacts on 
prey could impact the distribution of marine mammals in an area, 
potentially necessitating additional energy expenditure to find and 
capture prey. However, at the temporal and spatial scales anticipated 
for this activity, any such impacts on prey are not expected to impact 
the reproduction or survival of any individual marine mammals. Although 
studies assessing the impacts of offshore wind development on marine 
mammals are limited, the repopulation of wind energy areas by harbor 
porpoises (Brandt et al., 2016; Lindeboom et al., 2011) and harbor 
seals (Lindeboom et al., 2011; Russell et al., 2016) following the 
installation of wind turbines are promising. Overall, any impacts to 
marine mammal foraging capabilities due to effects on prey aggregation 
from the turbine presence and operation during the effective period of 
the proposed rule is likely to be limited.
    In general, impacts to marine mammal prey species are expected to 
be relatively minor and temporary due to the expected short daily 
duration of individual pile driving events and the relatively small 
areas being affected. In addition, NMFS does not expect HRG acoustic 
sources to impact fish and most sources are likely outside the hearing 
range of the primary prey species in the project area.
    Overall, the combined impacts of sound exposure and oceanographic 
impacts on marine mammal habitat resulting from the proposed activities 
would not be expected to have measurable effects on populations of 
marine mammal prey species. Prey species exposed to sound might move 
away from the sound source, experience TTS, experience masking of 
biologically relevant sounds, or show no obvious direct effects.
Reef Effects
    The presence of monopile, post-piled jacket, and pin pile 
foundations, scour protection, and cable protection will result in a 
conversion of the existing sandy bottom habitat to a hard bottom 
habitat with areas of vertical structural relief. This could 
potentially alter the existing habitat by creating an ``artificial reef 
effect'' that results in colonization by assemblages of both sessile 
and mobile animals within the new hard-bottom habitat (Wilhelmsson et 
al., 2006; Reubens et al., 2013; Bergstr[ouml]m et al., 2014; Coates et 
al., 2014). This colonization by marine species, especially hard-
substrate preferring species, can result in changes to the diversity, 
composition, and/or biomass of the area thereby impacting the trophic 
composition of the site (Wilhelmsson et al., 2010; Krone et al., 2013; 
Bergstr[ouml]m et al., 2014; Hooper et al., 2017; Raoux et al., 2017; 
Harrison and Rousseau, 2020; Taormina et al., 2020; Buyse et al., 
2022a; ter Hofstede et al., 2022).
    Artificial structures can create increased habitat heterogeneity 
important for species diversity and density (Langhamer, 2012). The WTG, 
OSS, and meteorological tower foundations will extend through the water 
column, which may serve to increase settlement of meroplankton or 
planktonic larvae on the structures in both the pelagic and benthic 
zones (Boehlert and Gill, 2010). Fish and invertebrate species are also 
likely to aggregate around the foundations and scour protection which 
could provide increased prey availability and structural habitat 
(Boehlert and Gill, 2010; Bonar et al., 2015). Further, instances of 
species previously unknown, rare, or nonindigenous to an area have been 
documented at artificial structures, changing the composition of the 
food web and possibly the attractability of the area to new or existing 
predators (Adams et al., 2014; de Mesel, 2015; Bishop et al., 2017; 
Hooper et al., 2017; Raoux et al., 2017; van Hal et al., 2017; Degraer 
et al., 2020; Fernandez-Betelu et al., 2022). Notably, there are 
examples of these sites becoming dominated by marine mammal prey 
species, such as filter-feeding species and suspension-feeding 
crustaceans (Andersson and [Ouml]hman, 2010; Slavik et al., 2019; 
Hutchison et al., 2020; Pezy et al., 2020; Mavraki et al., 2022).
    Numerous studies have documented significantly higher fish 
concentrations including species like cod and pouting (Trisopterus 
luscus), flounder (Platichthys flesus), eelpout (Zoarces viviparus), 
and eel (Anguilla anguilla) near in-water structures than in 
surrounding soft bottom habitat (Langhamer and Wilhelmsson, 2009; 
Bergstr[ouml]m et al., 2013; Reubens et al., 2013). In the German Bight 
portion of the North Sea, fish were most densely congregated near the 
anchorages of jacket foundations, and the structures extending through 
the water column were thought to make it more likely that juvenile or 
larval fish encounter and settle on them (Rhode Island Coastal 
Resources Management Council, 2010; Krone et al., 2013). In addition, 
fish can take advantage of the shelter provided by these structures 
while also being exposed to stronger currents created by the 
structures, which generate increased feeding opportunities and 
decreased potential for predation (Wilhelmsson et al., 2006). The 
presence of the foundations and resulting fish aggregations around the 
foundations is

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expected to be a long-term habitat impact, but the increase in prey 
availability could potentially be beneficial for some marine mammals.
    The most likely impact on marine mammal habitats from the project 
is expected to be from pile driving, which may affect marine mammal 
food sources such as forage fish and could also affect acoustic habitat 
effects on marine mammal prey (e.g., fish).
Water Quality
    Temporary and localized reduction in water quality will occur as a 
result of in-water construction activities. Most of this effect will 
occur during pile driving and installation of the cables, including 
auxiliary work such as dredging and scour placement. These activities 
will disturb bottom sediments and may cause a temporary increase in 
suspended sediment in the project area. Currents should quickly 
dissipate any raised total suspended sediment (TSS) levels, and levels 
should return to background levels once the project activities in that 
area cease. No direct impacts on marine mammals are anticipated due to 
increased TSS and turbidity; however, turbidity within the water column 
has the potential to reduce the level of oxygen in the water and 
irritate the gills of prey fish species in the proposed project area. 
However, turbidity plumes associated with the project would be 
temporary and localized, and fish in the proposed project area would be 
able to move away from and avoid the areas where plumes may occur. 
Therefore, it is expected that the impacts on prey fish species from 
turbidity, and therefore on marine mammals, would be minimal and 
temporary.
    Equipment used by US Wind within the project area, including ships 
and other marine vessels, potentially aircrafts, and other equipment, 
are also potential sources of by-products (e.g., hydrocarbons, 
particulate matter, heavy metals). All equipment is properly maintained 
in accordance with applicable legal requirements. All such operating 
equipment meets Federal water quality standards, where applicable. 
Given these requirements, impacts to water quality are expected to be 
minimal.
Acoustic Habitat
    Acoustic habitat is the soundscape, which encompasses all of the 
sound present in a particular location and time, as a whole when 
considered from the perspective of the animals experiencing it. Animals 
produce sound for, or listen for sounds produced by, conspecifics 
(communication during feeding, mating, and other social activities), 
other animals (finding prey or avoiding predators), and the physical 
environment (finding suitable habitats, navigating). Together, sounds 
made by animals and the geophysical environment (e.g., produced by 
earthquakes, lightning, wind, rain, waves) make up the natural 
contributions to the total acoustics of a place. These acoustic 
conditions, termed acoustic habitat, are one attribute of an animal's 
total habitat.
    Soundscapes are also defined by, and acoustic habitat influenced 
by, the total contribution of anthropogenic sound. This may include 
incidental emissions from sources such as vessel traffic or may be 
intentionally introduced to the marine environment for data acquisition 
purposes (as in the use of airgun arrays) or for Navy training and 
testing purposes (as in the use of sonar and explosives and other 
acoustic sources). Anthropogenic noise varies widely in its frequency, 
content, duration, and loudness and these characteristics greatly 
influence the potential habitat-mediated effects to marine mammals 
(please also see the previous discussion on Masking), which may range 
from local effects for brief periods of time to chronic effects over 
large areas and for long durations. Depending on the extent of effects 
to habitat, animals may alter their communications signals (thereby 
potentially expending additional energy) or miss acoustic cues (either 
conspecific or adventitious). Problems arising from a failure to detect 
cues are more likely to occur when noise stimuli are chronic and 
overlap with biologically relevant cues used for communication, 
orientation, and predator/prey detection (Francis and Barber, 2013). 
For more detail on these concepts, see: Barber et al., 2009; Pijanowski 
et al., 2011; Francis and Barber, 2013; Lillis et al., 2014.
    The term ``listening area'' refers to the region of ocean over 
which sources of sound can be detected by an animal at the center of 
the space. Loss of communication space concerns the area over which a 
specific animal signal, used to communicate with conspecifics in 
biologically important contexts (e.g., foraging, mating), can be heard, 
in noisier relative to quieter conditions (Clark et al., 2009). Lost 
listening area concerns the more generalized contraction of the range 
over which animals would be able to detect a variety of signals of 
biological importance, including eavesdropping on predators and prey 
(Barber et al., 2009). Such metrics do not, in and of themselves, 
document fitness consequences for the marine animals that live in 
chronically noisy environments. Long-term population-level consequences 
mediated through changes in the ultimate survival and reproductive 
success of individuals are difficult to study, and particularly so 
underwater. However, it is increasingly well documented that aquatic 
species rely on qualities of natural acoustic habitats, with 
researchers quantifying reduced detection of important ecological cues 
(e.g., Francis and Barber, 2013; Slabbekoorn et al., 2010) as well as 
survivorship consequences in several species (e.g., Simpson et al., 
2014; Nedelec et al., 2014).

Potential Effects From Offshore Wind Farm Operational Noise

    Although this proposed rulemaking primarily covers the noise 
produced from construction activities relevant to the Maryland Offshore 
Wind Project offshore wind facility, operational noise was a 
consideration in NMFS' analysis of the project, as all turbines would 
become operational within the effective dates of the rule (if issued). 
It is expected that all turbines would be operational in Q1 2028. Once 
operational, offshore wind turbines are known to produce continuous, 
non-impulsive underwater noise, primarily below 1 kHz (Tougaard et al., 
2020; St[ouml]ber and Thomsen, 2021).
    In both newer, quieter, direct-drive systems and older generation, 
geared turbine designs, recent scientific studies indicate that 
operational noise from turbines is on the order of 110 to 125 dB re 1 
[mu]Pa root-mean-square sound pressure level (SPL<INF>rms</INF>) at an 
approximate distance of 50 m (Tougaard et al., 2020). Recent 
measurements of operational sound generated from wind turbines (direct 
drive, 6 MW, jacket foundations) at Block Island wind farm (BIWF) 
indicate average broadband levels of 119 dB at 50 m from the turbine, 
with levels varying with wind speed (HDR, Inc., 2019). Interestingly, 
measurements from BIWF turbines showed operational sound had less tonal 
components compared to European measurements of turbines with gear 
boxes.
    Tougaard et al. (2020) further stated that the operational noise 
produced by WTGs is static in nature and lower than noise produced by 
passing ships. This is a noise source in this region to which marine 
mammals are likely already habituated. Furthermore, operational noise 
levels are likely lower than those ambient levels already present in 
active shipping lanes, such that operational noise would likely only be 
detected in very close proximity to the WTG (Thomsen et al., 2006; 
Tougaard et al.,

[[Page 539]]

2020). Similarly, recent measurements from a wind farm (3 MW turbines) 
in China found at above 300 Hz, turbines produced sound that was 
similar to background levels (Zhang et al., 2021). Other studies by 
Jansen and de Jong (2016) and Tougaard et al. (2009) determined that, 
while marine mammals would be able to detect operational noise from 
offshore wind farms (again, based on older 2 MW models) for several 
kilometers, they expected no significant impacts on individual 
survival, population viability, marine mammal distribution, or the 
behavior of the animals considered in their study (harbor porpoises and 
harbor seals). In addition, Madsen et al. (2006) found the intensity of 
noise generated by operational wind turbines to be much less than the 
noises present during construction, although this observation was based 
on a single turbine with a maximum power of 2 MW.
    More recently, St[ouml]ber and Thomsen (2021) used monitoring data 
and modeling to estimate noise generated by more recently developed, 
larger (10 MW) direct-drive WTGs. Their findings, similar to Tougaard 
et al. (2020), demonstrate that there is a trend that operational noise 
increases with turbine size. Their study predicts broadband source 
levels could exceed 170-dB SPL<INF>rms</INF> for a 10-MW WTG; however, 
those noise levels were generated based on geared turbines; newer 
turbines operate with direct drive technology. The shift from using 
gear boxes to direct drive technology is expected to reduce the levels 
by 10 dB. The findings in the St[ouml]ber and Thomsen (2021) study have 
not been experimentally validated, though the modeling (using largely 
geared turbines) performed by Tougaard et al. (2020) yields similar 
results for a hypothetical 10 MW WTG.
    Recently, Holme et al. (2023) cautioned that Tougaard et al. (2020) 
and St[ouml]ber and Thomsen (2021) extrapolated levels for larger 
turbines should be interpreted with caution since both studies relied 
on data from smaller turbines (0.45 to 6.15 MW) collected over a 
variety of environmental conditions. They demonstrated that the model 
presented in Tougaard et al. (2020) tends to potentially overestimate 
levels (up to approximately 8 dB) measured to those in the field, 
especially with measurements closer to the turbine for larger turbines. 
Holme et al. (2023) measured operational noise from larger turbines 
(6.3 and 8.3 MW) associated with three wind farms in Europe and found 
no relationship between turbine activity (power production, which is 
proportional to the blade's revolutions per minute) and noise level, 
though it was noted that this missing relationship may have been masked 
by the area's relatively high ambient noise sound levels. Sound levels 
(RMS) of a 6.3-MW direct-drive turbine were measured to be 117.3 dB at 
a distance of 70 m. However, measurements from 8.3 MW turbines were 
inconclusive as turbine noise was deemed to have been largely masked by 
ambient noise.
    Finally, operational turbine measurements are available from the 
Coastal Virginia Offshore Wind (CVOW) pilot pile project, where two 7.8 
m monopile WTGs were installed (HDR, 2023). Compared to BIWF, levels at 
CVOW were higher (10-30 dB) below 120 Hz, believed to be caused by the 
vibrations associated with the monopile structure, while above 120 Hz 
levels were consistent among the two wind farms.
    Overall, noise from operating turbines would raise ambient noise 
levels in the immediate vicinity of the turbines; however, the spatial 
extent of increased noise levels would be limited. NMFS proposes to 
require US Wind to measure operational noise levels. US Wind did not 
request, and NMFS is not proposing to authorize, take incidental to 
operational noise from WTGs. Therefore, the topic is not discussed or 
analyzed further herein.

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization through the regulations, which will inform 
both NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment) 
or has the potential to disturb a marine mammal or marine mammal stock 
in the wild by causing disruption of behavioral patterns, including, 
but not limited to, migration, breathing, nursing, breeding, feeding, 
or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as noise 
from pile driving and HRG surveys, could result in behavioral 
disturbance of marine mammals that qualifies as take. Impacts such as 
masking and TTS can contribute to the disruption of behavioral patterns 
and are accounted for within those takes proposed for authorization. 
There is also some potential for auditory injury (Level A harassment) 
of all marine mammals except North Atlantic right whales. However, the 
amount of Level A harassment that US Wind requested, and NMFS proposes 
to authorize, is low. While NMFS is proposing to authorize Level A 
harassment and Level B harassment, the proposed mitigation and 
monitoring measures are expected to minimize the amount and severity of 
such taking to the extent practicable (see Proposed Mitigation and 
Proposed Monitoring and Reporting).
    As described previously, no serious injury or mortality is 
anticipated or proposed to be authorized incidental to the specified 
activities. Even without mitigation, both pile driving activities and 
HRG surveys would not have the potential to directly cause marine 
mammal mortality or serious injury. However, NMFS is proposing measures 
to more comprehensively reduce impacts to marine mammal species. While, 
in general, there is a low probability that mortality or serious injury 
of marine mammals could occur from vessel strikes, the mitigation and 
monitoring measures contained within this proposed rule are expected to 
avoid vessel strikes (see Proposed Mitigation section). No other 
activities have the potential to result in mortality or serious injury.
    For acoustic impacts, we estimate take by considering: (1) acoustic 
thresholds above which the best available science indicates marine 
mammals will be behaviorally harassed or incur some degree of permanent 
hearing impairment; (2) the area or volume of water that will be 
ensonified above these levels in a day; (3) the density or occurrence 
of marine mammals within these ensonified areas; and (4) the number of 
days of activities. We note that while these factors can contribute to 
a basic calculation to provide an initial prediction of potential 
takes, additional information that can qualitatively inform take 
estimates is also sometimes available (e.g., previous monitoring 
results or average group size). Below, we describe the factors 
considered here in more detail and present the proposed take estimates.
    As described below, there are multiple methods available to predict 
density or occurrence and, for each species and activity, the largest 
value resulting from the three take estimation methods described below 
(i.e., density-based, PSO-based, or mean group size) was carried 
forward as the amount of take proposed for authorization, by Level B 
harassment. The amount of take

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proposed for authorization, by Level A harassment, reflects the 
density-based exposure estimates and, for some species and activities, 
consideration of other data such as mean group size.
    Below, we describe NMFS' acoustic thresholds, acoustic and exposure 
modeling methodologies, marine mammal density calculation methodology, 
occurrence information, and the modeling and methodologies applied to 
estimate take for each of the Project's proposed construction 
activities. NMFS has carefully considered all information and analysis 
presented by US Wind, as well as all other applicable information and, 
based on the best available science, concurs that the estimates of the 
types and amounts of take for each species and stock are reasonable, 
and is proposing to authorize the amount requested. NMFS notes the take 
estimates described herein for foundation installation can be 
considered conservative as the estimates do not reflect the 
implementation of clearance and shutdown zones for any marine mammal 
species or stock.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (Level B 
harassment) or to incur PTS of some degree (Level A harassment). A 
summary of all NMFS' thresholds can be found at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Level B Harassment
    Though significantly driven by received level, the onset of 
behavioral disturbance from anthropogenic noise exposure is also 
informed to varying degrees by other factors related to the source or 
exposure context (e.g., frequency, predictability, duty cycle, duration 
of the exposure, signal-to-noise ratio, distance to the source, ambient 
noise, and the receiving animal's hearing, motivation, experience, 
demography, behavior at time of exposure, life stage, depth) and can be 
difficult to predict (e.g., Southall et al., 2007, 2021; Ellison et 
al., 2012). Based on what the available science indicates and the 
practical need to use a threshold based on a metric that is both 
predictable and measurable for most activities, NMFS typically uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment.
    NMFS generally predicts that marine mammals are likely to be 
behaviorally harassed in a manner considered to be Level B harassment 
when exposed to underwater anthropogenic noise above the received sound 
pressure levels (SPL<INF>RMS</INF>) of 120 dB for continuous sources 
(e.g., vibratory pile driving, drilling) and above the received 
SPL<INF>RMS</INF> 160 dB for non-explosive impulsive or intermittent 
sources (e.g., impact pile driving, scientific sonar). Generally 
speaking, Level B harassment take estimates based on these behavioral 
harassment thresholds are expected to include any likely takes by TTS 
as, in most cases, the likelihood of TTS occurs at distances from the 
source less than those at which behavioral harassment is likely. TTS of 
a sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavioral patterns that would not otherwise 
occur.
    The proposed Project's construction activities include the use of 
impulsive or intermittent sources (i.e., impact pile driving, some HRG 
acoustic sources); therefore, the 160-dB re 1 [mu]Pa (rms) threshold is 
applicable to our analysis.
Level A Harassment
    NMFS' Technical Guidance for Assessing the Effects of Anthropogenic 
Sound on Marine Mammal Hearing (Version 2.0, Technical Guidance) (NMFS, 
2018) identifies dual criteria to assess auditory injury (Level A 
harassment) to five different marine mammal groups (based on hearing 
sensitivity) as a result of exposure to noise from two different types 
of sources (impulsive or non-impulsive). As dual metrics, NMFS 
considers onset of PTS (Level A harassment) to have occurred when 
either one of the two metrics is exceeded (i.e., metric resulting in 
the largest isopleth). As described above, US Wind's proposed 
activities include the use of impulsive sources. NMFS' thresholds 
identifying the onset of PTS are provided in table 8. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                            Table 8--Permanent Threshold Shift (PTS) Onset Thresholds
                                                  [NMFS, 2018]
----------------------------------------------------------------------------------------------------------------
                                                         PTS onset thresholds * (received level)
             Hearing group             -------------------------------------------------------------------------
                                                Impulsive                          Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans..........  L,0-pk,flat: 219 dB; LE,,  LE,, LF,24h: 199 dB.
                                         LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans..........  L,0-pk,flat: 230 dB; LE,,  LE,, MF,24h: 198 dB.
                                         MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.........  L,0-pk,flat: 202 dB; LE,,  LE,, HF,24h: 173 dB.
                                         HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)....  L,0-pk.flat: 218 dB; LE,,  LE,, PW,24h: 201 dB.
                                         PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)...  Cell 9: L,0-pk,flat: 232   Cell 10: LE,, OW,24h: 219 dB.
                                         dB; LE,, OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
  onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
  associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (L,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO, 2017). The subscript
  ``flat'' is included to indicate peak sound pressure are flat weighted or unweighted within the generalized
  hearing range of marine mammals (i.e., 7 Hz to 160 kHz). The subscript associated with cumulative sound
  exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF, and HF
  cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The weighted
  cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e., varying exposure
  levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the
  conditions under which these thresholds will be exceeded.


[[Page 541]]

    Below, we describe the assumptions and methodologies used to 
estimate take, in consideration of acoustic thresholds and appropriate 
marine mammals density and occurrence information, for WTG, OSS, and 
meteorological tower installation, and HRG surveys. Resulting distances 
to thresholds, densities used, activity-specific exposure estimates (as 
relevant to the analysis), and activity-specific take estimates can be 
found in each activity subsection below. At the end of this section, we 
present the amount of annual and 5-year take that US Wind requested, 
and NMFS proposes to authorize, from all activities combined.

Acoustic and Exposure Modeling

    The predominant underwater noise associated with the construction 
of the Project results from impact pile driving. US Wind employed 
Marine Acoustic, Inc., (MAI) to conduct acoustic modeling to better 
understand sound fields produced during these activities (see appendix 
A of ITA Application). The basic acoustic modeling approach is to 
characterize the sounds produced by the source and determine how the 
sounds propagate within the surrounding water column. MAI derived 
surrogate source spectra for each pile type and conducted sophisticated 
propagation modeling (as described below). To assess the potential for 
take from impact pile driving, MAI also conducted animal movement 
modeling; MAI estimated species-specific exposure probability by 
considering the range- and depth-dependent sound fields in relation to 
animal movement in simulated representative construction scenarios. 
More details on these acoustic source modeling, propagation modeling 
and exposure modeling methods are described below.
    The amount of sound generated during pile driving varies with the 
energy required to drive piles to a desired depth and depends on the 
sediment resistance encountered. Sediment types with greater resistance 
require hammers that deliver higher energy strikes and/or an increased 
number of strikes relative to installations in softer sediment. Maximum 
sound levels usually occur during the last stage of impact pile driving 
where the greatest resistance is encountered (Betke, 2008). Therefore, 
variations in hammer energies must be taken into account during 
acoustic source modeling.
    For impact pile driving, MAI derived surrogate source spectra for 
each impact pile driving scenario based upon available measured or 
modeled source spectra for hammer energies and pile diameters similar 
to those expected for the Project impact pile driving activities (table 
9). Source spectra (or a representative of sound by frequency) were 
then adjusted based upon pile diameters and hammer energies that would 
be used by US Wind using pile driving scaling laws (Von Pein et al., 
2022), which are derived from a large number of measurements for wide 
ranges of hammer energies, pile diameters, and other parameters.
    MAI used the predicted spectrum of an 11-m diameter monopile 
developed for the South Fork Wind Farm (Denes et al., 2018; Denes et 
al., 2021) as a surrogate source signature in modeling of the 11-m 
monopile for the WTG foundations for the Project. The surrogate 
spectrum was predicted assuming an IHC S-4000 hammer with a maximum 
strike energy of 4,000 kJ, while the planned scenario includes an 11-m 
monopile with a hammer capable of a 4,400-kJ maximum strike energy of 
4,400 kJ. Hence, MAI adjusted the spectra accordingly to account for 
slightly higher maximum source levels. The expected difference in sound 
level between 4,000 and 4,400 kJ can be approximated using energy 
scaling laws (Von Pein et al., 2022), and is estimated to be minimal 
(0.4 dB).
    MAI used a 3-m post-piled pin pile source spectrum in the modeling 
for impact pile driving of OSS foundations that was based upon the mean 
of the measured spectra of a 6-m pile reported by Bruns et al. (2014) 
and a 3.5-m FINO2 pile reported by Matuschek and Betke (2009) (see 
appendix A of the LOA application for additional detail on deriving 
source spectra for the 3-m pin pile). The resulting representative 
source level for the 3-m pin pile (208 dB<INF>SEL</INF>) is comparable 
to the estimated value for a 2.4-m diameter post-piled pin pile driven 
by a 1,700-kJ Menck hammer (209 dB<INF>SEL</INF>) measured by Molnar et 
al. (2020). Molnar et al. (2020) estimated this value by back 
calculating the source level assuming transmission loss of 15 * 
log<INF>10</INF> (range) based upon a measured SEL of 188 dB at a range 
of 25 m from the pile during uninitiated impact pile driving. This 
suggests that the modeling for the 3-m pin pile is representative of a 
post-piled pin pile.
    The spectrum derived for the 3-m pin pile was scaled to represent 
the 1.8 m pin piles for the Met tower based upon the maximum hammer 
energy and pile diameter using relationships presented in Von Pein et 
al. (2022). The 3-m post-piled pin pile source levels being scaled down 
by 8 dB and a SEL source level of 199 dB for the 1.8-m pin pile (see 
section 4.4, ``Source Characterization,'' in appendix A of the ITA 
application for a full description of scaling) (table 11).
    Once acoustic modeling for the monopile at a maximum hammer energy 
of 4,400 kJ was performed, the modeled sound fields were then adjusted 
by a broadband sound reduction to represent the lower strike energy 
levels (i.e., 1,100 kJ, 2,200 kJ, and 3,300 kJ) planned for portions of 
the monopile installation. To account for the differences in hammer 
energies planned for use and the maximum hammer energy (4,400 kJ), the 
modeled spectra for the 4,400-kJ hammer was scaled using 
10*log<INF>10</INF>(E<INF>1</INF>/E<INF>2</INF>) (where E<INF>1</INF> 
is the lower strike energy level and E<INF>2</INF> is the modeled 
energy level), to represent each of the lower proposed hammer energies 
(Von Pein et al., 2022). This resulted in the application of scaling 
factors of -6, -3, and -1 dB to represent the 1,100 kJ, 2,200 kJ, and 
3,300 kJ hammer energies, respectively, as shown in table 10. The ramp 
up of hammer energy is accounted for when calculating the cumulative 
SEL over the installation of each monopile using the number of strikes 
at each energy level. The broadband scaling factor (table 10) was 
subtracted from the modeled received levels for the indicated number of 
strikes before the cumulative SEL was calculated. This hammer strike 
energy progression for monopile installation was considered in the 
calculation of the acoustic ranges and acoustic exposures. Although US 
Wind originally considered and modeled maximum hammer strikes at an 
energy of 4,400 kJ, the final hammer schedule (table 10) did not 
include any strikes at the 4,400 kJ energy level as US Wind has 
indicated they do not plan to use hammer energies above 3,300 kJ. SEL 
acoustic ranges assume a hammer schedule up to a maximum energy of 
3,300 kJ, however, peak and RMS acoustic ranges assume a hammer 
schedule up to a maximum energy of 4, 400 kJ (tables 14 and 15). For 
additional details on surrogate source spectra development and scaling, 
please see section 4.4, ``Source Characterization,'' in appendix A of 
US Wind's ITA application.
    US Wind would use at least two noise abatement systems (NAS) during 
all pile driving associated with foundation installations, such as a 
double bubble curtain or single bubble curtain and an encapsulated 
bubble or foam sleeve, to reduce sound levels. NAS, such as bubble 
curtains, are often used to decrease the sound levels radiated from a 
source. Hence, hypothetical broadband attenuation levels of 0 dB, 10 
dB, and 20 dB were incorporated into the foundation source models to 
gauge effects on the ranges to thresholds given

[[Page 542]]

these levels of attenuation (appendix A of the ITA application). 
Although two attenuation levels were evaluated, NMFS anticipates that 
the noise attenuation systems ultimately chosen will be capable of 
reliably reducing source levels by 10 dB; therefore, this assumption 
was carried forward in this analysis for monopile, jacket, and Met 
tower foundation pile driving installation. See the Proposed Mitigation 
section for more information regarding the justification for the 10-dB 
assumption.
    Key modeling assumptions for the monopiles and pin piles are listed 
in table 10 (additional modeling details and input parameters can be 
found in appendix A of the ITA application). Hammer energy schedules 
for monopiles (11-m), 3-m pin piles, and 1.8-m pin piles (are also 
provided in table 10 and the resulting broadband source levels of the 
monopiles and pin piles are presented in table 11.

                          Table 9--Surrogate Spectra Hammer Energies and Pile Diameters
----------------------------------------------------------------------------------------------------------------
                                                                           Representative
          Foundation type           Maximum hammer      Representative      hammer energy        Reference
                                      energy (kJ)         foundation            (kJ)
----------------------------------------------------------------------------------------------------------------
11-m Monopile.....................       \1\ 4,400  11-m monopile........           4,400  Denes et al., 2021.
3-m Pin Pile......................           1,500  6-m pin pile \2\.....           (\4\)  Bruns et al., 2014.
                                                    3.5-m FINO2 pile \3\.                  Matuschek and Betke,
                                                                                            2009.
1.8-m Pin Pile....................             500  3-m Skirt Pile.......           1,500  MAI, 2022.
----------------------------------------------------------------------------------------------------------------
\1\ US Wind confirmed with NMFS that their maximum hammer energy will not exceed 3,300 kJ (Jodziewicz, 2023).
\2\ Measured at a distance of 15 m.
\3\ Measured at a distance of 500 m.
\4\ Hammer energies were not available.


                                Table 10--Key Piling Assumptions and Hammer Energy Schedules for Monopiles and Pin Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         Hammer
                                                     Hammer    Duration at  Strikes per     Strike       energy       Seabed    Piling time   Number of
                 Foundation type                  energy (kJ)     energy       minute       count       scaling    penetration    per day     piles per
                                                               level (min)                            factor (dB)   depth (m)      (min)         day
--------------------------------------------------------------------------------------------------------------------------------------------------------
11-m Monopile \1\...............................        1,100           30           20          600           -6           50          120            1
                                                        2,200           60           40        2,400           -3
                                                        3,300           30           60        1,800           -1
                                                    \1\ 4,400  ...........  ...........  ...........            0
3-m Pin Pile....................................    \3\ 1,500          480           40       19,200          n/a    \5\ 50-60      \6\ 480            4
1.8-m Pin Pile..................................      \3\ 500          360      \4\ 8.3        2,988          n/a    \5\ 51-53      \6\ 360            3
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ While US Wind would use a hammer capable of striking the pile at 4,400 kJ, US Wind has committed to not using hammer energies about 3,300 kJ
  (Jodziewicz, 2023). Modeled sound fields were adjusted by broadband sound reduction to represent the lower strike energy levels planned for monopile
  installation.
\2\ Assumed this maximum hammer energy for the duration of installation.
\3\ Although the fractional number of 8.3 hammer strikes per minute is unlikely to be accomplished during installation, this number instead of the
  rounded, more realistic value of 8 strikes per minute is included as it results in a higher number of total hammer blows than if the rounded blows per
  minute value were used.
\4\ Subject to final design.
\5\ Piling time refers to all pin piles installed within a 24-hour period.


           Table 11--Broadband Source Levels, Assuming 10-dB Attenuation, Derived From Source Modeling
----------------------------------------------------------------------------------------------------------------
                                                         Source level (dB) at 1 m
                                                 ---------------------------------------
                                    Max hammer     SELss SPL
            Pile type               energy (kJ)     (dB) re      Peak SPL     RMS SPL             Source
                                        \a\       1[mu] Pa\2\    (dB) re      (dB) re
                                                      m\2\       1[mu] Pa     1[mu] Pa
----------------------------------------------------------------------------------------------------------------
11-m Monopile...................           4,400          214          262          224  Denes et al. (2018;
                                                                                          2021).
3-m Pin Pile b c................           1,500          198          249          208  Bruns et al., 2014;
                                                                                          Matuschek and Betke,
                                                                                          2009.
1.8 m Pin Pile \c\..............             500          189          237          199  MAI, 2022.
----------------------------------------------------------------------------------------------------------------
SELss = single strike SEL.
\a\ Assumes MHU 4400 hammer.
\b\ Based upon measured spectra of a 6-m pile reported by Bruns et al. (2014).
\c\ Based upon measured spectra of a 3.5-m pile reported by Matuschek and Betke (2009).

    After calculating source levels, MAI used the Navy Standard 
Parabolic Equation (NSPE) propagation model to estimate distances to 
NMFS' harassment thresholds. The NSPE is a modern iteration of the 
well-known Range-dependent Acoustic Model (RAM) (Collins, 1993). The 
propagation of sound through the environment can be modeled by 
predicting the acoustic propagation loss--a measure, in decibels, of 
the decrease in sound level between a source and a receiver some 
distance away. Geometric spreading of acoustic waves is the predominant 
way by which propagation loss occurs. Propagation loss also happens 
when the sound is absorbed and scattered within the water column, as 
well as absorbed, scattered, and reflected at the water surface and 
within the seabed. Propagation loss depends on the acoustic properties 
of the ocean and seabed and its value changes with frequency.
    A single representative location of intermediate water depth (27 m) 
was selected for the underwater acoustic propagation modeling analysis. 
A sensitivity analysis was conducted to assess the differences in 
acoustic propagation at the selected intermediate-depth model location 
(27 m), the deepest location (42 m), and shallowest location (13 m) 
within the

[[Page 543]]

Project Area. The results of the sensitivity analysis indicated that 
although acoustic propagation was not significantly different between 
the sites, lower received levels were predicted at the shallowest and 
deepest locations relative to the intermediate depth modeling location. 
Therefore, of the three considered modeling locations, the intermediate 
depth (27 m) location was selected to provide the most conservative and 
representative modeling results. MAI included physical site parameters, 
such as bathymetry, water surface roughness, seasonal sound velocity 
profiles, wind speed, and sediment type/size into the acoustic 
propagation model. The model generated the predicted noise during 
impact pile driving scenarios for the 11-m monopiles, 3-m pin piles, 
and 1.8-m pin piles. The May sound velocity profile was selected to be 
representative of the proposed pile driving construction period as this 
profile represented the largest acoustic propagation ranges (see 
appendix A of the ITA application). Pile driving sources were included 
in the propagation model as vertical line arrays. The pile beampattern 
was created from a vertical line array of elements with 1-m spacing 
from the surface to the seafloor. This representative array was used to 
create a frequency-specific beampattern (see appendix A of the ITA 
application). MAI followed this propagation process for each one-third 
octave center frequency in the bands from 10 Hz to 25 kHz with radials 
running at 10[deg] intervals to a range of 50 km. Based upon the source 
levels derived for each pile driving source (table 11), the one-third 
octave band source levels were added to each transmission loss value to 
produce a received level value at each range, depth, and bearing point. 
The combined sound fields for each frequency were then summed to 
generate a representative broadband sound field. This process was 
followed for each radial around each pile driving source to produce an 
N * two-dimensional grid of received sound levels in range, depth and 
bearing. The resulting predicted acoustic SEL field was assessed with 
the appropriate marine mammal weighting functions for low-frequency, 
mid-frequency, and high-frequency cetaceans as well as pinnipeds in 
water (NMFS, 2018). These weighting functions were applied to 
individual sound received levels to reflect the susceptibility of each 
hearing group to noise-induced threshold shifts.
    To estimate the probability of exposure of animals to sound above 
NMFS' harassment thresholds during foundation installation, MAI 
integrated the sound fields generated from the source and propagation 
models described above with marine mammal species-typical behavioral 
parameters (e.g., dive parameters, swimming speed, and course/direction 
changes) using the Acoustic Integration Model (AIM) (Frankel et al., 
2002). AIM is a Monte Carlo based statistical model in which multiple 
iterations of realistic predictions of acoustic source use as well as 
animal distribution and movement patterns are conducted to provide 
statistical predictions of estimated effects from exposure to 
underwater sound transmissions. For each species, separate AIM 
simulations were developed and iterated for each modeling scenario and 
activity location. During the simulations, animats (modeled receivers 
representing individual marine mammals) were randomly distributed in 
the model simulation area and the predicted received sound level was 
estimated every 30 seconds to create a history over a 24-hour period. 
Animats were programmed to reflect off the boundaries of the model 
simulation area and remain within this simulation area. The model 
simulation area was delineated by four boundaries consisting of lines 
of latitude (37.5[deg] to 39[deg] N) and lines of longitude (73.75[deg] 
to 75.5[deg] W). These lines extended one latitude or longitude beyond 
the model simulation area to ensure that the region was large enough to 
capture anticipated substantial behavior reactions and an adequate 
number of animats would be modeled in all directions. This model area 
box, which included the model simulation area, was approximately 20,000 
km\2\ in size. Animats were also pre-programmed to move every 30 
seconds based upon species-specific behaviors, yet were limited in 
movements by the coastline and minimum occurrence depth for each 
species, based upon scientific literature. Animat movement behavior 
parameters included diving, swimming, aversion, and residency patterns 
based upon existing scientific literature for each species in the model 
(see table B-1 in appendix A of the ITA application). Animat movement 
behavior parameters for seals were modeled based upon harbor seal 
parameters (see table B-1 in appendix A of the ITA application). At the 
end of each 30-second interval, the received sound level (in dB RMS) 
for each animat was recorded.
    The output of the simulation is the exposure history for each 
animat within the simulation, and the combined history of all animats 
gives a probability density function of exposure during the project. 
The acoustic exposure history for each animat was analyzed to produce 
Level A harassment and Level B harassment exposure estimates. MAI 
estimated the amount of potential acoustic exposures above NMFS' Level 
A (PTS) harassment and Level B (behavioral) harassment thresholds 
predicted to occur within the Project area from any pile driving event 
(see below in section WTG, OSS, and Met tower Foundation Installation 
for more details). Once an animat received an exposure from a sound 
field greater than the Level A harassment (PTS) threshold, the animat 
was eliminated from further analysis; animats not exposed to sound 
fields greater than the Level A harassment threshold were further 
analyzed to determine whether the animat would be exposed to sound 
fields greater than the Level B harassment (behavioral) threshold. 
Therefore, animats were not counted as both Level A harassment and 
Level B harassment exposures.
    To obtain acoustic exposure estimates for each species per pile, 
the numbers of modeled animat sound exposures were multiplied by the 
ratio of the modeled animat density to the real-world marine mammal 
density estimate for the buffered Lease Area (Roberts et al., 2023, see 
below for more details on how a 5.25-km buffer zone around the Lease 
Area was calculated and densities were estimated). The animat exposure 
estimates per pile are the product of the number of modeled exposures 
multiplied by the ratio of real-world density per month (Roberts et 
al., 2023) to model density. The daily exposures were then multiplied 
by the planned number of piles driven each month and then summed for 
the year for each of years 1-3 when pile driving would take place. US 
Wind plans to install only one monopile per day, four 3-m pin piles per 
day, and three 1.8-m pin piles per day (for Met tower).

Density and Occurrence

    In this section, we provide the information about marine mammal 
density, presence, and group dynamics that informed the take 
calculations for all activities. US Wind applied the 2022 Duke 
University Marine Geospatial Ecology Laboratory Habitat-based Marine 
Mammal Density Models for the U.S. Atlantic (Duke Model-Roberts et al., 
2016; Roberts et al., 2023) to estimate take from foundation 
installation and HRG surveys (please see each activity subsection below 
for the resulting densities). The models estimate absolute density 
(individuals/

[[Page 544]]

100 km\2\) by statistically correlating sightings reported on shipboard 
and aerial surveys with oceanographic conditions. For most marine 
mammal species, densities are provided on a monthly basis. Where 
monthly densities are not available (e.g., pilot whales), annual 
densities are provided. Moreover, some species are represented as 
guilds (e.g., seals (representing Phocidae spp., primarily harbor and 
gray seals and pilot whales (representing short-finned and long-finned 
pilot whales)).
    The Duke habitat-based density models delineate species' density 
into 5 * 5 km (3.1 * 3.1 mi) grid cells. US Wind calculated mean 
monthly (or annual) densities for each species for each grid cell 
within the Lease Area and 5.25 km buffer perimeter around the Lease 
Area that represented the largest 10-dB attenuated expected range to 
NMFS' harassment thresholds. The buffer perimeter was calculated based 
upon the largest range to Level B harassment threshold, which was 5.25 
km for impact pile driving of 11-m monopiles at a maximum hammer energy 
of 4,400 kJ. This distance was added as a buffer surrounding the Lease 
Area for all pile driving and HRG activities, and marine mammal 
densities were compiled for this buffered area (see figure 6-1 in the 
LOA application). All 5 x 5 km grid cells in the models that fell 
within the analysis polygon were considered in the calculations. If the 
centroid of the grid cell, or a minimum of half the cell, fell within 
the buffered lease area boundary, the cell was included in the density 
analysis (see section 3.2 of appendix A of the ITA application for 
additional information on how the centroid of each grid cell was 
determined).
    Densities were computed monthly for each species where monthly 
densities were available. For the pilot whale guild (i.e., long-finned 
and short-finned), monthly densities are unavailable, so annual mean 
densities were used instead. Additionally, the models provide density 
for pilot whales and seals as guilds. To obtain density estimates for 
long-finned and short-finned pilot whales, US Wind scaled the guild 
density by the relative abundance of each species in the Project Area 
based upon sighting, biopsy, and stranding data (Garrison and Rosel, 
2017; Palka et al., 2021; Hayes et al., 2023; Maryland Marine Mammal 
Stranding Program, 2023). Biopsy and stranding data indicated that 
short-finned pilot whales are more likely than long-finned pilot whales 
to occur along the Maryland coast (Garrison and Rosel, 2017; Hayes et 
al., 2023). Based on these data, US Wind partitioned total pilot whale 
exposures based upon the assumption that 60 percent of exposures would 
be to short-finned pilot whales and 40 percent of exposures would be to 
long-finned pilot whales.
    The equation below shows how local occurrence scaling is applied to 
compute density for pilot whales.

D<INF>short-finned</INF> = D<INF>both</INF> x 
(N<INF>short-finned</INF>/(N<INF>short-finned</INF> + 
N<INF>long-finned</INF>)),

where D represents density and N represents occurrence.

    Density estimates for gray seals, harbor seals, and harp seals were 
not scaled by local occurrence as limited at-sea data was available for 
these seal species in the Project Area (i.e., no local abundance 
estimates could be calculated). Although harp seals are considered 
extralimital in the Project Area, the MD DNR and National Aquarium at 
Baltimore (NAB) have documented harp seal strandings inshore of the 
Lease Area (NAB, 2023a). Over the past 10 years, stranding reports of 
harp seals in Maryland have become more common in areas such as Ocean 
City (NAB, 2023b). Although stranding records for harbor and gray seals 
exist as well for coastal Maryland, stranding records may not 
accurately reflect the numbers and distribution of seals offshore in 
the vicinity of the Project Area. In addition, the Roberts et al. 
(2023) density data includes all three species of seals in the seal 
guild. MAI conducted animat modeling using harbor seal behavior 
parameters (see appendix B, ``Animat Modeling Parameters,'' of appendix 
A of the ITA application) and, while behavioral parameters may differ 
slightly between seal species, NMFS concurs that harbor seal behavior 
is a suitable proxy for all seals as any behavioral differences between 
seal species are not likely to be large enough to require separate 
modeling. Harbor seals are likely to be the prevalent seal species in 
the Project Area and, given the difficulty predicting the likely 
proportion of exposures by species, exposure estimates for seals are 
presented for gray seals, harbor seals, and harp seals collectively.
    The density models (Roberts et al., 2023) also do not distinguish 
between bottlenose dolphin stocks and only provide densities for 
bottlenose dolphins as a species. For impact pile driving, take of each 
bottlenose dolphin stock was allocated based upon the progression of 
pile driving from the southeastern corner of Lease Area in year 1 
(2025) towards the western portion of the Lease Area in years 2 and 3, 
as described further in the WTG, OSS, and Met Tower Foundation 
Installation section. Mean monthly density estimates are provided in 
table 12.

          Table 12--Mean Monthly Marine Mammal Density Estimates (Animals per 100 km\2\) Considering a 5.25-km Buffer Around the Lease Area \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   Species                      Jan      Feb     March    April     May      June     July     Aug      Sept     Oct      Nov      Dec
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale..................    0.075    0.076    0.063    0.045    0.008    0.003    0.001    0.001    0.002    0.004    0.011    0.036
Fin whale...................................    0.214    0.184    0.154    0.135    0.094    0.111    0.041    0.028     0.04    0.037    0.045    0.151
Humpback whale..............................    0.091    0.062    0.083    0.187    0.142    0.102     0.02    0.011    0.027    0.112    0.143    0.088
Minke whale.................................    0.069    0.089    0.114    0.687    0.750    0.155     0.05     0.02     0.01    0.055    0.025    0.064
Sei whale...................................    0.029    0.021    0.034    0.061     0.02    0.005    0.001        0    0.001    0.006    0.017    0.046
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale \ 2\...........................                                                     0.002
--------------------------------------------------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin....................    0.003    0.001    0.002    0.013    0.046     0.09    0.396    1.505    0.475    0.335    0.243    0.032
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pantropical spotted dolphin \2\.............                                                     0.004
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin \3\......................    3.855    1.316    1.659    5.668   15.225    15.92   18.323   20.608    16.47   14.689    17.13   11.705
--------------------------------------------------------------------------------------------------------------------------------------------------------
Short-finned pilot whale and long-finned
 pilot whale \4\............................                                                     0.039
--------------------------------------------------------------------------------------------------------------------------------------------------------
Common dolphin..............................    4.298    1.869    1.972    3.268    3.289    1.471    1.301    0.501    0.044    0.765    5.746    7.939
Risso's dolphin.............................    0.045    0.006    0.006    0.056    0.051    0.018    0.017    0.018     0.01    0.023    0.092    0.169
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 545]]

 
Rough-toothed dolphin \2\...................                                                     0.002
--------------------------------------------------------------------------------------------------------------------------------------------------------
Striped dolphin \ 2\........................                                                     0.004
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise.............................    3.653    3.336    2.586    3.191    0.615    0.002    0.001    0.001        0        0    0.002    2.025
Seals \4\...................................   16.993   12.084    7.569   11.879    9.843    1.087    0.408    0.236    0.405    2.158    3.222   15.741
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Species that were modeled as a representative group rather than as individual species.
\2\ Annual densities are shown for species with insufficient sightings to derive density estimates by month.
\3\ Two stocks of common bottlenose dolphin (the western North Atlantic migratory coastal stock and the western North Atlantic offshore stock) may occur
  in the Project area. Both stocks are presented here.
\4\ Densities are only available for the combined seal and pilot whale groups in the Roberts et al. (2023) dataset. Seals include harbor seals, gray
  seals, and harp seals were in the seal guild.
\5\ Density estimates are presented yet take is not requested for these species due to low density estimates and few occurrences in the Project area.

    For some species and activities, PSO survey data for the Lease Area 
(RPS, 2023; Smultea, 2022) and group size data compiled from RPS (2013) 
and DoN (2017b) indicate that the density-based exposure estimates may 
be insufficient to account for the number of individuals of a species 
that may be encountered during the planned activities. This is 
particularly true for uncommon or rare species with very low densities 
in the models. Hence, consideration of other data is required to ensure 
the potential for take is adequately assessed.
    In cases where the acoustic exposure estimate for a species was 
less than the mean group size, the take request was increased to the 
mean group size (in some cases multiple groups were assumed) and 
rounded to the nearest integer (table 13). Requested take for pile 
driving activities was adjusted according to average group size in 
table 13 and rounded to the nearest whole number.
    Additional detail regarding the density and occurrence as well as 
the assumptions and methodology used to estimate take for specific 
activities is included in the activity-specific subsections below and 
in section 6.1 of the ITA application. Average group sizes used in take 
estimates, where applicable, for all activities are provided in table 
13.

    Table 13--Average Marine Mammal Group Sizes Used in Take Estimate
                              Calculations
------------------------------------------------------------------------
            Species              Mean group size         Source \1\
------------------------------------------------------------------------
Fin whale 2 3.................               1.64  RPS, 2023.
North Atlantic right whale \3\               2.00  RPS, 2023.
Humpback whale \3\............               1.95  RPS, 2023.
Atlantic spotted dolphin \3\..               5.89  RPS, 2023.
Pantropical spotted dolphin                  4.33  RPS, 2023.
 \3\.
Common dolphin \3\............               7.00  RPS, 2023.
Killer whale \4\..............                2.5  DoN, 2017.
Long-finned pilot whale \3\...               11.0  DoN, 2017.
Short-finned pilot whale \3\..               16.0  DoN, 2017.
Risso's dolphin \3\...........               8.47  DoN, 2017.
Rough-toothed dolphin \4\.....               5.50  DoN, 2017.
Striped dolphin \4\...........              45.59  DoN, 2017.
Harbor porpoise \5\...........               3.00  RPS, 2023.
------------------------------------------------------------------------
\1\ PSO data from the Smultea Associate PSO interim report (Smultea,
  2022) was not used to assess group sizes as the activity documented in
  the report occurred outside the pile driving and HRG micro-siting
  periods planned for the Project.
\2\ For fin whales, US Wind adjusted take by Level A harassment
  according to group size for years 1 and 3.
\3\ US Wind adjusted take by Level B harassment for these species
  according to group size.
\4\ For killer whales, rough-toothed dolphins, and striped dolphins,
  NMFS adjusted take by Level B harassment according to the assumption
  that one group of each species would be encountered per year of impact
  pile driving.
\5\ For harbor porpoises, US Wind adjusted take by Level A harassment
  according to group size for years 2 and 3 and take by Level B
  harassment according to group size for years 1 and 3.

WTG, OSS, and Met Tower Foundation Installation

    Here, we describe the results from the acoustic, exposure, and take 
estimate methodologies outlined above for WTG, OSS, and meteorological 
tower installation pile driving activities that have the potential to 
result in harassment of marine mammals. We present acoustic ranges to 
Level A harassment and Level B harassment thresholds, densities, 
exposure estimates and take estimates following the aforementioned 
assumptions (e.g., construction and hammer schedules).
    As previously described, MAI integrated the results from acoustic 
source and propagation modeling into an animal movement model to 
calculate acoustic ranges for 16 marine mammal species considered 
common in the project area. The acoustic ranges represent distances to 
NMFS' harassment isopleths independent of movement of a receiver. The 
pile progression schedule (refer back to table 3) was taken into 
account when calculating the acoustic ranges to SEL thresholds (see 
appendix A of the ITA application of additional details on 
calculations). The modeled sound fields represented the single strike 
SELs at the modeled strike energies (table 11). The single strike SEL 
fields were converted to cumulative SEL fields based on the different 
strike energy levels and the number of expected hammer blows at each 
energy. The difference between a single strike SEL and the cumulative 
SEL was calculated using 10 * log<INF>10</INF> (number of strikes). MAI 
calculated

[[Page 546]]

acoustic ranges for the 11-m monopile assuming one monopile would be 
installed per day using 4,800 impact hammer strikes (table 3). For the 
3-m pin piles for the OSSs scenario, MAI calculated the acoustic ranges 
assuming 4 pin piles would be installed per day with 19,200 hammer 
strikes each day (table 3). MAI calculated acoustic ranges for the 1.8-
m pin piles for the Met tower foundation assuming 3 pin piles would be 
installed per day with an associated 2,998 impact hammer strikes that 
day (table 3). The maximum received level-over-depth was calculated at 
each range step and along each radial. The maximum and 95th percentile 
acoustic range to the marine mammal regulatory thresholds were then 
calculated for each of the modeling scenarios (table 14). The maximum 
acoustic range value represents the greatest distance along any single 
radial. The 95th percentile acoustic range (R<INF>95</INF><not-eq>) is 
an improved representation of the range to the threshold as it 
eliminates major outliers and better represents all the modeled 
radials. All acoustic ranges presented to regulatory thresholds are the 
95th percentile range. PTS peak sound pressure level thresholds and the 
Level B behavioral harassment threshold (160-dB RMS sound pressure 
level) represent instantaneous exposures. The distances to the PTS dB 
SEL threshold are likely an overestimate as it assumes an animal 
remains at the distance for the entire duration of pile driving 
(however, an animal could come closer for a shorter period of time and 
still incur PTS or an animal could move further away and, thus, not be 
exposure to the entire duration of piling in a 24-hour period that 
would result in the exceedance of the PTS SELcum threshold). Acoustic 
ranges to the Level A harassment and Level B harassment thresholds are 
shown in tables 14 and 15, respectively.

    Table 14--Acoustic Ranges (R95%) in Meters (m) to Marine Mammal Level A Harassment Thresholds (SEL and Peak \1\) During Impact Pile Driving 11-m
                                        Monopiles, 3-m Pin Piles, and 1.8-m Pin Piles, Assuming 10-dB Attenuation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Distances to Level A harassment thresholds (m)
                                                                 ---------------------------------------------------------------------------------------
                                                                      Low-frequency         Mid-frequency        High-frequency            Phocids
                                     Maximum hammer    Activity         cetaceans             cetaceans             cetaceans      ---------------------
           Pile installed              energy (kJ)     duration  ------------------------------------------------------------------
                                                      (min/day)    219 Lp,    183 LE,    230 Lp,    185 LE,    202 Lp,    155 LE,    218 Lp,    185 LE,
                                                                      pk        24hr        pk        24hr        pk        24hr        pk        24hr
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
11 m Monopile......................       \2\ 3,300          120        <50      2,900        <50          0        200        250        <50        100
3 m Pin Piles......................           1,500          480        <50      1,400        <50          0        <50        100        <50         50
1.8 m Pin Pile.....................             500          240        <50         50        <50          0        <50          0        <50          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ SEL acoustic ranges assumed a maximum hammer energy of 3,300 kJ while peak acoustic ranges assumed a maximum hammer energy of 4,400 kJ. US Wind
  confirmed with NMFS that they would not utilize hammer energies above 3,300 kJ (Jodziewicz, 2023).


 Table 15--Acoustic Ranges (R95%) in Meters (m) to Marine Mammal Level B
   Harassment Thresholds (160-dB SPL) During Impact Pile Driving 11-m
      Monopiles, 3-m Pin Piles, and 1.8-m Pin Piles, Assuming 10-dB
                               Attenuation
------------------------------------------------------------------------
                                                    Distance to Level B
        Pile installed            Hammer energy     harassment threshold
                                       (kJ)             (m) (160 dB)
------------------------------------------------------------------------
11-m Monopile.................              4,400                  5,250
3-m Pin Piles.................              1,500                    500
1.8-m Pin Pile................                500                    100
------------------------------------------------------------------------

    To estimate take from foundation installation activities, US Wind 
used the pile installation construction schedule shown in table 16, 
assuming 22 total days of foundation installation activities during the 
MarWin campaign, 58 total days of pile installation activities during 
the Momentum Wind campaign, and 39 total days of pile installation 
during the Future Development campaign.

                                       Table 16--Pile Installation Construction Schedule Used for Take Estimation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Expected
                                                                                                             number of                     Total  number
                                                                                             Number of        days to      Installation         of
            Campaign                  Year           Structure         Foundation  type        piles          install      rate per  day   installation
                                                                                                            foundation                       days for
                                                                                                               type                          campaign
--------------------------------------------------------------------------------------------------------------------------------------------------------
MarWin..........................         2025  WTG..................  11-m Monopile.....              21              21               1              22
                                               OSS..................  3-m Pin Piles.....               4               1               4
Momentum Wind...................         2026  WTG..................  11-m Monopile.....              55              55               1              58
                                               OSS..................  3-m Pin Piles.....               8               2               4
                                               Met tower............  1.8-m Pin Piles...               3               1               3
Future Development..............         2027  WTG..................  11-m Monopile.....              38              38               1              39
                                               OSS..................  3-m Pin Piles.....               4               1               4
--------------------------------------------------------------------------------------------------------------------------------------------------------

    To estimate the amount of Level A harassment and Level B harassment 
that may occur incidental to foundation installation, US Wind used the 
animat modeling described above to integrate the predicted received 
sound level fields of the impact pile driving resulting from the 
acoustic modeling of the impact pile driving sources (acoustic ranges) 
with the four-dimensional movements of marine mammals. US Wind used the 
modeled SEL and peak

[[Page 547]]

SEL received by each individual animat over the duration of the model 
simulation (24 hours) to calculate the potential for that animat to 
have been exposed to sound levels exceeding the Level A harassment 
threshold. To estimate the amount of Level B (behavioral) harassment 
that may occur incidental to foundation installation, US Wind used the 
modeled root mean square (RMS) sound pressure levels to estimate the 
potential for marine mammal behavioral responses for animats that did 
not experience exposure to sound levels that exceeded Level A 
harassment thresholds. Modeled results for Level A harassment and Level 
B harassment exposure estimates were subsampled to reflect the duty 
cycle of each construction activity's source to create multiple 
estimates of sound exposure for each source and marine mammal 
combinations. The number of modeled exposures were multiplied by the 
ratio of real-world density and animat model densities to obtain per 
pile animat exposure estimates. US Wind calculated maximum acoustic 
exposure estimates on an annual basis according to the annual 
installation schedule (table 16) for the 11-m monopile, 3-m skirt pile, 
and 1.8-m pin pile, assuming a 10-dB sound level attenuation each year. 
As described above, MAI multiplied the final acoustic per pile exposure 
estimate for each modeled species by the number of piles to be 
installed per month to obtain a monthly exposure estimate for each 
species. To obtain annual exposure estimates, MAI summed the monthly 
exposure estimates for each modeled species for each year of pile 
driving (years 1-3). MAI conducted these calculations for both Level A 
harassment and Level B harassment exposure estimates for each modeled 
species. Table 17 identifies the amount of take calculated for impact 
installation of monopiles for WTGs, table 18 identifies the amount of 
take calculated for impact installation of 3-m pin piles for jacket 
foundations for OSSs, and table 19 identifies the amount of take 
calculated for impact installation of 1.8-m pin piles for the Met 
tower. No take by Level A harassment is anticipated or proposed for 
authorization during impact pile driving of 3-m pin piles for OSSs 
(table 18) or 1.8-m pin piles for the Met tower (table 19). Take 
proposed for authorization for all impact pile driving activities 
combined across years 1-3 and carried forward for this proposed rule as 
shown in table 20.
    Bottlenose dolphin estimated take by Level B harassment was 
distributed between the coastal stock and offshore stock based upon the 
where impact pile driving would take place within the Lease Area 
throughout years 1-3 and how pile driving locations may overlap the 
expected ranges of the coastal and offshore stocks. North of Cape 
Hatteras, NC, the coastal stocks of bottlenose dolphins are expected to 
occur in waters less than 25 m deep and within 34 km of shore (Kenney, 
1990; Torres et al., 2003). Impact pile driving would progress from the 
southeastern corner of the Lease Area in year 1 and extend west during 
years 2 and 3. During year 1, impact pile driving would occur furthest 
offshore, with the ensonified zone above NMFS harassment threshold 
beyond the expected range of the coastal stock, therefore, US Wind 
allocated 100 percent of estimated take by Level B harassment during 
year 1 to the offshore stock. During years 2 and 3, pile driving would 
take place further west than year 1 and within the range of the coastal 
stock as well. As pile driving is expected to progress westward into 
shallower waters and further into the range of the coastal stock during 
years 2 and 3, estimated take by Level B harassment would increase for 
the coastal stock as compared to the offshore stock as the pile driving 
locations progress west. US Wind distributed estimated take by Level B 
harassment between stocks for years 2 and 3 as follows: year 2 (70 
percent offshore stock, 30 percent coastal stock) and year 3 (15 
percent offshore stock; 85 percent coastal stock).
    For Atlantic spotted dolphins, it was expected that five groups 
would be observed during pile driving activities in year 1 and 10 
groups would be observed in years 2 and 3 (RPS, 2023). Although 
acoustic exposures were calculated as zero for each species of pilot 
whales each year, based upon sighting data in the area (DoN, 2017), it 
was assumed that one pilot whale group of each species may be 
encountered. US Wind adjusted pilot whale requested take by Level B 
harassment for years 1 to 3. For Risso's dolphin, it was expected that 
two groups of nine would be observed for each year of pile driving 
(years 1 through 3) and taken by Level B harassment. Although killer 
whales, rough-toothed dolphins, and striped dolphins are expected to be 
rare in the Project Area due to habitat preferences, a very small 
amount of exposures (e.g., 0.22) were modeled; therefore, it was 
assumed one group of each species may be encountered during the LOA 
period. For harbor porpoises, it was expected that one group of three 
(RPS, 2023) would be taken by Level A harassment in years 2 and 3 and 
one group of three would be taken by Level B harassment in years 1 and 
3. US Wind adjusted requested take for harbor porpoises, accordingly. 
Year 2 request for take by Level B harassment for harbor porpoises 
during pile driving activities was not adjusted for group size as the 
estimated acoustic exposure was greater than the average expected group 
size, and the acoustic exposure estimate was rounded up to the nearest 
whole number. Correcting for group size for these species is used as a 
conservative measure to ensure all animals in a group are accounted for 
in the take request.

   Table 17--Modeled Level A Harassment and Level B Harassment Exposures Assuming 10-dB Sound Attenuation During Impact Pile Driving of 11-m Monopile
                                 Foundations In the Buffered Lease Area Over 3 Years and Proposed Take (in Parentheses)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Level A harassment (SELcum) \6\               Level B harassment (160 dBrms)
                                                                                               ---------------------------------------------------------
                                                              ---------------------------------
                    Marine mammal species                        Year 1     Year 2     Year 3    Year 1  (2025)                         Year 3  (2027)
                                                                 (2025)     (2026)     (2027)          \8\        Year 2  (2026) \9\         \10\
                                                                  \8\        \9\        \10\
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale 1 2...............................   0.01 (0)   0.05 (0)   0.02 (0)      \3\ 0.06 (2)        \3\ 0.24 (2)        \3\ 0.08 (2)
Fin whale \1\................................................   \3\ 0.39   \3\ 1.16   \3\ 0.68      \4\ 3.94 (4)      \4\ 11.57 (12)        \4\ 6.83 (7)
                                                                     (2)        (2)        (2)
Humpback whale...............................................   \3\ 0.42   \3\ 1.55   \3\ 0.67      \4\ 2.52 (3)       \4\ 9.29 (10)        \4\ 4.05 (5)
                                                                     (2)        (2)        (2)
Minke whale..................................................   \4\ 0.49   \4\ 5.55   \4\ 1.11      \4\ 2.96 (3)      \4\ 33.31 (34)        \4\ 6.66 (7)
                                                                     (1)        (6)        (2)
Sei whale \1\................................................    \4\ 0.1   \4\ 0.12   \4\ 0.02      \4\ 0.11 (1)        \4\ 0.83 (1)        \4\ 0.17 (1)
                                                                     (1)        (1)        (1)
Killer whale.................................................      0 (0)      0 (0)      0 (0)      \3\ 0.08 (3)        \3\ 0.22 (3)        \3\ 0.15 (3)
Atlantic spotted dolphin.....................................      0 (0)      0 (0)      0 (0)    \3\ 14.07 (24)      \3\ 38.86 (54)      \3\ 50.75 (54)
Bottlenose dolphin (offshore stock/coastal stock) \5\........      0 (0)      0 (0)      0 (0)  \4\ 846.85 (847)        \4\ 2,320.67        \4\ 1,711.04
                                                                                                                             (2,321)             (1,721)
Common dolphin...............................................      0 (0)      0 (0)      0 (0)    \4\ 28.63 (29)    \4\ 233.12 (234)      \4\ 96.48 (97)
Long-finned pilot whale......................................      0 (0)      0 (0)      0 (0)        \3\ 0 (11)          \3\ 0 (11)          \3\ 0 (11)
Short-finned pilot whale.....................................      0 (0)      0 (0)      0 (0)        \3\ 0 (16)          \3\ 0 (16)          \3\ 0 (16)

[[Page 548]]

 
Pantropical spotted dolphin..................................      0 (0)      0 (0)      0 (0)      \3\ 0.17 (5)        \3\ 0.45 (5)        \3\ 0.31 (5)
Risso's dolphin..............................................      0 (0)      0 (0)      0 (0)      \3\ 0.79 (9)        \3\ 4.33 (9)        \3\ 1.94 (9)
Rough toothed dolphin........................................      0 (0)      0 (0)      0 (0)      \3\ 0.04 (6)        \3\ 0.11 (6)        \3\ 0.08 (6)
Striped dolphin..............................................      0 (0)      0 (0)      0 (0)     \3\ 0.17 (46)       \3\ 0.45 (46)       \3\ 0.31 (46)
Harbor porpoise \6\..........................................      0 (0)   \3\ 1.19   \3\ 0.01      \3\ 0.03 (3)      \3\ 15.83 (16)        \3\ 0.08 (3)
                                                                                (3)        (3)
Gray seal \5\................................................      0 (0)      0 (0)      0 (0)    \4\ 17.87 (18)    \4\ 234.31 (235)      \4\ 30.02 (31)
Harbor seal \5\..............................................
Harp seal \5\................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Listed as Endangered under the Endangered Species Act (ESA)
\2\ Level A harassment exposures were initially estimated for this species, but due to the mitigation measures that US Wind will be required to abide
  by, no Level A harassment take is expected, nor proposed to be authorized.
\3\ Proposed take adjusted according to group size in table 13.
\4\ Proposed take rounded to the nearest whole number.
\5\ Two stocks of common bottlenose dolphin (the western North Atlantic migratory coastal stock and the western North Atlantic offshore stock) may occur
  in the Project area. Both stocks are presented together here.
\6\ Peak levels were not considered because SEL distances were larger than peak in all cases, with the exception of harbor porpoise. Peak exposure
  estimates were greater than the cumulative SEL exposure estimates for harbor porpoises due to the frequency weighting of the SEL-based metric and a
  lower peak threshold for high-frequency cetaceans compared to other marine mammal hearing groups.
\7\ Exposure estimates include harbor seals, gray seals, and harp seals combined.
\8\ During the MarWin campaign in year 1, US Wind plans to install 21 11-m monopiles and 4 3-m pin piles.
\9\ During the Momentum Wind campaign in year 2, US Wind plans to install 55 11-m monopiles, 8 3-m pin piles, and 3 1.8-m pin piles.
\10\ During the Future Development campaign in year 3, US Wind plans to install 38 11-m monopiles and 4 3-m pin piles.


 Table 18--Modeled Level B Harassment Exposures (Assuming 10-dB Sound Attenuation) Due To Impact Pile Driving of
                 3-m Pin Piles In the Buffered Lease Area Over 3 Years \1\ and Proposed Take \8\
----------------------------------------------------------------------------------------------------------------
                                                           Level B harassment (160 dB rms)
                                   -----------------------------------------------------------------------------
                                        Year 1 (2025) \5\         Year 2 (2026) \6\         Year 3 (2027) \7\
       Marine mammal species       -----------------------------------------------------------------------------
                                      Exposure     Proposed     Exposure     Proposed     Exposure     Proposed
                                      estimate       take       estimate       take       estimate       take
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale \2\....            0            0            0            0            0            0
Fin whale 2 3.....................         0.03            2         0.06            2         0.03            2
Humpback whale \3\................         0.01            2         0.01            2         0.01            2
Minke whale \4\...................         0.04            1         0.08            1         0.04            1
Sei whale \2\.....................            0            0            0            0            0            0
Killer whale......................            0            0            0            0            0            0
Atlantic spotted dolphin \3\......         0.17          \6\         0.35            6         0.17            6
Bottlenose dolphin (offshore stock/        9.53           10        19.06           19         9.53           10
 coastal stock) 4 5...............
Common dolphin \3\................         0.57            7         1.14            7         0.57            7
Long-finned pilot whale...........            0            0            0            0            0            0
Short-finned pilot whale..........            0            0            0            0            0            0
Pantropical spotted dolphin.......            0            0            0            0            0            0
Risso's dolphin \3\...............         0.01            9         0.03            9         0.01            9
Rough toothed dolphin.............            0            0            0            0            0            0
Striped dolphin...................            0            0            0            0            0            0
Harbor porpoise...................            0            0            0            0            0            0
Gray seal \6\.....................         0.08            0         0.16            0         0.08            0
Harbor seal \ 6\..................
Harp seal \6\.....................
----------------------------------------------------------------------------------------------------------------
\1\ Modeled acoustic exposure estimates for all species were zero for take by Level A harassment. Therefore, no
  take by Level A harassment is anticipated or proposed for authorization.
\2\ Listed as Endangered under the Endangered Species Act (ESA)
\3\ Proposed take is adjusted according to group size in table 13.
\4\ Proposed take is rounded to the nearest whole number.
\5\ Two stocks of common bottlenose dolphin (the western North Atlantic migratory coastal stock and the western
  North Atlantic offshore stock) may occur in the Project area. Both stocks are presented together here.
\6\ Exposure estimates include harbor seals, gray seals, and harp seals combined.
\7\ During the MarWin campaign in year 1, US Wind plans to install 21 11-m monopiles and 4 3-m pin piles.
\8\ During the Momentum Wind campaign in year 2, US Wind plans to install 55 11-m monopiles, 8 3-m pin piles,
  and 3 1.8-m pin piles.
\9\ During the Future Development campaign in year 3, US Wind plans to install 38 11-m monopiles and 4 3-m pin
  piles.


[[Page 549]]


  Table 19--Modeled Level B Harassment Exposures (Assuming 10-dB Sound
Attenuation) Due To Impact Pile Driving of 1.8-m Pin Piles (Assume Three
  Total Pin Piles for the Met Tower) in the Buffered Lease Area During
                  Year 2 \1\ \2\ and Proposed Take \8\
------------------------------------------------------------------------
                                         Level B
                                        harassment          Level B
       Marine mammal species        acoustic exposure      harassment
                                      estimate (160      proposed take
                                          dBrms)            estimate
------------------------------------------------------------------------
North Atlantic right whale \3\....                  0                  0
Fin whale 3 4.....................               0.01                  2
Humpback whale \4\................               0.01                  2
Minke whale \5\...................               0.01                  1
Sei whale \3\.....................                  0                  0
Killer whale......................                  0                  0
Atlantic spotted dolphin..........                  0                  0
Bottlenose dolphin (offshore stock/              1.91                  2
 coastal stock) 5 6...............
Common dolphin \4\................               0.18                  7
Long-finned pilot whale...........                  0                  0
Short-finned pilot whale..........                  0                  0
Pantropical spotted dolphin.......                  0                  0
Risso's dolphin...................                  0                  0
Rough toothed dolphin.............                  0                  0
Striped dolphin...................                  0                  0
Harbor porpoise...................                  0                  0
Gray seal \7\.....................               0.09                  0
Harbor seal \7\...................
Harp seal \7\.....................
------------------------------------------------------------------------
\1\ In-water construction activities to install the Met tower would take
  place only during year 2.
\2\ Modeled acoustic exposure estimates for all species were zero for
  take by Level A harassment. Therefore, no take by Level A harassment
  is anticipated or proposed for authorization.
\3\ Listed as Endangered under the Endangered Species Act (ESA).
\4\ Proposed take is adjusted according to group size in table 13.
\5\ Proposed take is rounded to the nearest whole number.
\6\ Two stocks of common bottlenose dolphin (the western North Atlantic
  migratory coastal stock and the western North Atlantic offshore stock)
  may occur in the Project area. Both stocks are presented together
  here.
\7\ Exposure estimates include harbor seals, gray seals, and harp seals.
\8\ During the Momentum Wind campaign in year 2, US Wind plans to
  install 55 11-m monopiles, 8 3-m pin piles, and 3 1.8-m pin piles.


  Table 20--Proposed Takes by Level A Harassment and Level B Harassment for All Impact Pile Driving Activities in the Buffered Lease Area Over 3 Years
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Proposed take by Level A harassment    Proposed take by Level B harassment
                                                                Population -----------------------------------------------------------------------------
                    Marine mammal species                        estimate      Year 1       Year 2       Year 3       Year 1       Year 2       Year 3
                                                                               (2025)       (2026)       (2027)       (2025)       (2026)       (2027)
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale \1\...............................          338            0            0            0            2            2            2
Fin whale 1 2................................................        6,802            2            2            2            6           16            9
Humpback whale \2\...........................................        1,396            2            2            2            5           14            7
Minke whale..................................................       21,968            1            6            2            4           36            8
Sei whale \1\................................................        6,292            1            1            1            1            1            1
Killer whale \3\.............................................          UNK            0            0            0            3            3            3
Atlantic spotted dolphin \4\.................................       39,921            0            0            0           30           60           60
Bottlenose dolphin (coastal stock) \5\.......................        6,639            0            0            0            0          703        1,462
Bottlenose dolphin (offshore stock) \5\......................       62,851            0            0            0          857        1,639          259
Common dolphin...............................................      172,974            0            0            0           36          248          104
Long-finned pilot whale \6\..................................       39,215            0            0            0           11           11           11
Short-finned pilot whale \6\.................................       28,924            0            0            0           16           16           16
Pantropical spotted dolphin..................................        6,593            0            0            0            5            5            5
Risso's dolphin \7\..........................................       35,215            0            0            0           18           18           18
Rough toothed dolphin \3\....................................          136            0            0            0            6            6            6
Striped dolphin \3\..........................................       67,306            0            0            0           46           46           46
Harbor porpoise \8\..........................................       95,543            0            3            3            3           16            3
Gray seal \9\................................................       27,300            0            0            0           18          235           31
Harbor seal \9\..............................................       61,336
Harp seal \9\................................................         7.6M
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Listed as Endangered under the Endangered Species Act (ESA).
\2\ Total proposed take by Level A harassment was increased according to average group size (table 13), rounded to the nearest whole number, for years 1
  and 3.
\3\ Total proposed take by Level B harassment was increased according to average group size for each year of pile driving activities (table 13). It was
  assumed that one group would be encountered per year.
\4\ Total proposed take by Level B harassment was increased according to average group size for each year of pile driving activities. Proposed takes for
  Atlantic spotted dolphins are based upon the assumption that 5 groups of 6 (RPS, 2023) will be observed during year 1 of pile driving activities, and
  10 groups of 6 would be observed during each of years 2 and 3 pile driving activities.
\5\ Bottlenose dolphin take by Level B harassment was allocated to each stock based upon the direction of the progression of pile driving throughout
  project years 1-3 as follows: year 1 (100 percent offshore stock); year 2 (70 percent offshore stock; 30 percent coastal stock); year 3 (15 percent
  offshore stock; 85 percent coastal stock).

[[Page 550]]

 
\6\ Total pilot whale acoustic exposures were low, and apportioning take as 60 percent short-finned pilot whale and 40 percent long-finned pilot whale
  resulted in calculated takes of less than one for both species. As these calculated acoustic exposure estimates were less than average group size for
  both species, requested take by Level B harassment was based upon the assumption of one group of each species being encountered during each year of
  pile driving activities (table 13).
\7\ Total proposed take by Level B harassment was increased according to average group size for each year of pile driving activities. Proposed take by
  Level B harassment for Risso's dolphins is based upon the assumption that two groups of nine (DoN, 2017) would be observed during each year of pile
  driving.
\8\ Total proposed take was increased according to average group size. It is expected that one group of harbor porpoises would be taken by Level A
  harassment during years 2 and 3 and by Level B harassment in years 1 and 3. Proposed take represents monopile installation only as exposure estimates
  for pin pile installation were zero.
\9\ Total proposed take by Level B harassment for seals includes harbor seals, gray seals, and harp seals.

HRG Surveys

    US Wind's proposed HRG survey activity includes the use of 
impulsive sources (i.e., boomers, sparkers) that have the potential to 
harass marine mammals. The list of equipment proposed is in table 4 
(see Detailed Description of the Specified Activity).
    Authorized takes would be by Level B harassment only in the form of 
disruption of behavioral patterns for individual marine mammals 
resulting from exposure to noise from certain HRG acoustic sources. 
Based primarily on the characteristics of the signals produced by the 
acoustic sources planned for use, Level A harassment is neither 
anticipated nor proposed to be authorized. Therefore, the potential for 
Level A harassment is not evaluated further in this document. US Wind 
did not request, and NMFS is not proposing to authorize, take by Level 
A harassment incidental to HRG surveys. No serious injury or mortality 
is anticipated to result from HRG survey activities.
    Specific to HRG surveys, in order to better consider the narrower 
and directional beams of the sources, NMFS has developed a tool, 
available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance, for determining 
the distances at which sound pressure level (SPLrms) generated from HRG 
surveys reach the 160-dB threshold. The equations in the tool consider 
water depth, frequency-dependent absorption, and some directionality to 
refine estimated ensonified zones. The isopleth distances corresponding 
to the Level B harassment threshold for each type of HRG equipment with 
the potential to result in harassment of marine mammals were calculated 
per NOAA Fisheries' Interim Recommendation for Sound Source Level and 
Propagation Analysis for High Resolution Geophysical Sources. Input for 
HRG equipment specifications are provided in table 4. Micro-siting HRG 
surveys could occur throughout the Lease Area, therefore, US Wind 
assumed a maximum depth of 42 m (137.8 ft) which corresponds to the 
maximum depth of the Lease Area. The distances to the 160-dB RMS re 1 
[mu]Pa isopleth for Level B harassment are presented in table 21.

  Table 21--Distances Corresponding to the Level B Harassment Threshold
                          for HRG Equipment \1\
------------------------------------------------------------------------
                                                            Horizontal
                                                           distance (m)
       HRG survey equipment            Equipment type       to Level B
                                                            harassment
                                                             threshold
------------------------------------------------------------------------
Applied Acoustics S Boomer........  SBP: Boomer.........            35.2
AA Dura Spark 400 tip.............  SBP: Sparker........             200
------------------------------------------------------------------------
\1\ Of note, NMFS has performed a preliminary review of a report
  submitted by Rand (2023), that includes measurements of the Geo-Marine
  Geo-Source 400 sparker (400 tip, 800 J), and suggests that NMFS is
  assuming lower source and received levels than appropriate in its
  assessments of HRG impacts. NMFS has determined that the values in our
  assessment remain appropriate, based on the model methodology (i.e.,
  source level propagated using spherical spreading) here predicting a
  peak level 3 dB louder than the maximum measured peak levels at the
  closest measurement range in Rand (2023). NMFS will continue reviewing
  Rand (2023) and other available data relevant to these sources.

    The survey activities that have the potential to result in Level B 
harassment (160-dB SPL) include the noise produced by Applied Acoustics 
S Boomer or AA Dura Spark sparker (table 21), of which the Dura Spark 
sparker results in the greatest calculated distance to the Level B 
harassment criteria at 200 m (656 ft). US Wind has applied the 
estimated distance of 200 m (656 ft) to the 160 dB<INF>RMS90</INF> 
percent re 1 [mu]Pa Level B harassment criteria as the basis for 
determining potential take from all HRG sources. All noise-producing 
survey equipment is assumed to be operated concurrently. One vessel 
will operate at a time during HRG surveys.
    The zone of influence (ZOI) is the total ensonified area around the 
sound source over a 24-hour period. The maximum ZOI was estimated by 
considering the distance of the daily vessel track line (111.2 km) and 
the largest distance from the sound source to the isopleth for the 
Level B harassment threshold (200 m for the Dura Spark sparker). US 
Wind calculated the distance of the daily vessel track line by 
multiplying the estimated average speed of the vessel (4 kn; 2.06 m/s) 
by a maximum of 15 hours per survey per day. The following equation was 
used to calculate the maximum ZOI:

ZOI = (Distance traveled/day * 2r) + r\2\,

where

r is the maximum distance to the Level B threshold (200 m) and the 
maximum ZOI was 44.6 km\2\.

    Exposure calculations assumed that there would be 14 days of HRG 
surveying per year during years 2 (2026) and 3 (2027). As described in 
the ITA application, density data were mapped within the buffered Lease 
Area using geographic information systems, and these data were updated 
based upon the revised data from the Duke Model (Roberts et al., 2023). 
Although HRG surveys are expected to occur between April and June each 
year, to be conservative, the maximum monthly average density for each 
species for an entire year was used and carried forward in the take 
calculations (table 21). Calculations assume a daylight-only schedule 
for HRG surveys. NMFS rounded exposure estimates to the nearest whole 
number to generate take estimates, except for species for which take is 
not proposed due to mitigation measures (table 22).

[[Page 551]]



    Table 22--Marine Mammal Densities (Animals/100 km\2\), Exposure Estimates, and Proposed Takes by Level B
                              Harassment From HRG Surveys During Years 2 and 3 1 2
----------------------------------------------------------------------------------------------------------------
                                      Maximum                 Year 2                          Year 3
                                      monthly    ---------------------------------------------------------------
      Marine mammal species        density (No./     Exposure                        Exposure
                                      km\2\)         estimate      Proposed take     estimate      Proposed take
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale \3\..         0.00076             0.5           \4\ 2             0.5           \4\ 2
Fin whale \3\...................           0.214             1.3           \4\ 2             1.3           \4\ 2
Humpback whale..................           0.187             1.2          \4\ 02             1.2           \4\ 2
Minke whale.....................            0.75             4.7               5             4.7               5
Sei whale \3\...................           0.061             0.4               0             0.4               0
Killer whale....................           0.002            0.01               0            0.01               0
Atlantic spotted dolphin........           1.505             9.4               9             9.4               9
Bottlenose dolphin \5\..........          20.608           128.7             129           128.7             129
Common dolphin..................           7.939            49.6              50            49.6              50
Pilot whale species \6\.........           0.039             0.2               0             0.2               0
Pantropical spotted dolphin.....           0.004            0.02               0            0.02               0
Risso's dolphin.................           0.169             1.1           \4\ 8             1.1           \4\ 8
Rough-toothed dolphin...........           0.002            0.01               0            0.01               0
Striped dolphin.................           0.004            0.02               0            0.02               0
Harbor porpoise.................           3.653            22.8              23            22.8              23
Gray seal \7\...................          16.993           106.1             106           106.1             106
Harbor seal \7\
Harp seal \7\
----------------------------------------------------------------------------------------------------------------
\1\ Density estimates are calculated from the 2022 Duke Habitat-Based Marine Mammal Density Models (Roberts et
  al., 2016; Roberts et al., 2023). Maximum monthly average density for each marine mammal species was used for
  take calculations.
\2\ The survey area accounts for waters within and around the Lease Area.
\3\ Listed as Endangered under the ESA.
\4\ Proposed take adjusted for group size. See table 13 for average group size estimates.
\5\ Two stocks of common bottlenose dolphin (the western North Atlantic migratory coastal stock and the western
  North Atlantic offshore stock) may occur in the Project area. Both stocks are presented here.
\6\ Densities are only available for the combined seal and pilot whale groups in the Roberts et al. (2023)
  dataset.
\7\ Proposed take by Level B harassment is for harbor seals, gray seals, and harp seals.

Total Take Across All Activities

    The amount of Level A harassment and Level B harassment NMFS 
proposes to authorize incidental to all Project activities combined 
(i.e., pile driving to install WTG, OSS, and Met tower foundations, and 
HRG surveys are shown in table 24. The annual amount of take that is 
expected to occur in each year based on US Wind's current schedules is 
provided in table 24. The year 1 proposed take includes impact pile 
driving of monopiles for WTGs and 3-m pin piles for the OSSs. Proposed 
take during year 2 includes all activities occurring: WTG, OSS, and Met 
tower foundation installation and HRG surveys. Year 3 proposed take 
includes WTG and OSS foundation installation and HRG surveys. As 
mentioned above, the timing of installation activities and HRG surveys 
would depend upon vessel availability, contractor selection, weather, 
and additional factors. However, in the event that activities are 
delayed or spread over 4-5 years (instead of 3 years), the maximum 
annual amount of take for each species would not exceed the numbers 
listed in table 25.
    For each species, if the acoustic exposure (for pile driving 
activities or HRG surveys) was less than the average group size (table 
13), the average group size was rounded to the nearest integer and used 
as the proposed take estimate by Level A harassment or Level B 
harassment. If the acoustic exposure was greater than the average group 
size (table 13), the acoustic exposure was rounded to the nearest 
integer and used as the proposed take estimate by Level A harassment or 
Level B harassment.
    For the species for which modeling was conducted, the take 
estimates are considered conservative for a number of reasons. The 
amount of take proposed to be authorized assumes the most impactful 
scenario with respect to project design and schedules. As described in 
the Description of Specified Activity section, US Wind may use suction-
buckets to install OSS foundations. Should US Wind use suction-bucket 
foundations, take would not occur from OSS foundation installation as 
noise levels would not be elevated to the degree there is a potential 
for take (i.e., no pile driving is involved with installing suction 
buckets). All calculated take incorporated the highest densities for 
any given species in any given month. In addition, the amount of 
proposed Level A harassment does not fully account for the likelihood 
that marine mammals would avoid a stimulus when possible before the 
individual accumulates enough acoustic energy to potentially cause 
auditory injury, or the effectiveness of the proposed monitoring and 
mitigation measures (with exception of North Atlantic right whales 
given the enhanced mitigation measures proposed for this species).

     Table 23--Proposed Takes by Level A Harassment and Level B Harassment for All Activities Proposed To Be
                                       Conducted Annually Over 3 Years \1\
----------------------------------------------------------------------------------------------------------------
                                             Year 1                    Year 2                    Year 3
                                   -----------------------------------------------------------------------------
       Marine mammal species          Level A      Level B      Level A      Level B      Level A      Level B
                                     harassment   harassment   harassment   harassment   harassment   harassment
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale 2 3....            0            2            0            4            0            4
Fin whale 2 3.....................            2            6            2           18            2           11

[[Page 552]]

 
Humpback whale \3\................            2            5            2           16            2            9
Minke whale \3\...................            1            4            6           41            2           13
Sei whale \3\.....................            1            1            1            1            1            1
Killer whale \3\..................            0            3            0            3            0            3
Atlantic spotted dolphin \3\......            0           30            0           69            0           69
Coastal bottlenose dolphin \4\....            0            0            0          703            0        1,462
Offshore bottlenose dolphin \4\...            0          857            0        1,639            0          259
Bottlenose dolphin \5\............            0            0            0          129            0          129
Common dolphin....................            0           36            0          298            0          154
Long-finned pilot whale \3\.......            0           16            0           16            0           16
Short-finned pilot whale \3\......            0           11            0           11            0           11
Pantropical spotted dolphin \3\...            0            5            0            5            0            5
Risso's dolphin...................            0           18            0           26            0           26
Rough-toothed dolphin \3\.........            0            6            0            6            0            6
Striped dolphin \3\...............            0           46            0           46            0           46
Harbor porpoise \3\...............            0            3            3           39            3           26
Gray seal \6\.....................            0           18            0          341            0          147
Harbor seal \6\
Harp seal \6\
----------------------------------------------------------------------------------------------------------------
\1\ The final rule and LOA, if issued, would be effective from January 1, 2025 through December 31, 2029.
\2\ Listed as Endangered under the ESA.
\3\ Average group size applied to the proposed take estimate.
\4\ Proposed take represents take from impact pile driving activities.
\5\ Proposed take numbers represent requested take from HRG survey activities. Assumes take from the coastal and
  offshore stock of bottlenose dolphins.
\6\ Proposed take includes harbor seals, gray seals, and harp seals.


  Table 24--Proposed Takes of Marine Mammals (by Level A Harassment and
 Level B Harassment) for All Activities Proposed To Be Conducted During
     the Construction of the Project and Over the Course of the Rule
------------------------------------------------------------------------
                                         Total proposed   Total proposed
         Marine mammal species          take by Level A  take by Level B
                                           harassment       harassment
------------------------------------------------------------------------
North Atlantic right whale 1 2........                0               10
Fin whale 1 2.........................                6               35
Humpback whale \2\....................                6               30
Minke whale \2\.......................                9               58
Sei whale \2\.........................                3                3
Killer whale \3\......................                0                9
Atlantic spotted dolphin \2\..........                0              168
Coastal bottlenose dolphin \3\........                0            2,165
Offshore bottlenose dolphin \3\.......                0            2,755
Bottlenose dolphin \4\................                0              258
Common dolphin........................                0              488
Long-finned pilot whale \2\...........                0               48
Short-finned pilot whale \2\..........                0               33
Pantropical spotted dolphin \2\.......                0               15
Risso's dolphin.......................                0               70
Rough-toothed dolphin \3\.............                0               18
Striped dolphin \3\...................                0              138
Harbor porpoise \2\...................                6               68
Gray seal \5\.........................                0              496
Harbor seal.\5\
Harp seal.\5\
------------------------------------------------------------------------
\1\ The final rule and LOA, if issued, would be effective from January
  1, 2025 through December 31, 2029.
\2\ Listed as Endangered under the ESA.
\3\ Total 3-year proposed take by Level B harassment includes impact
  pile driving activities only.
\4\ Total 3-year proposed take by Level B harassment includes HRG survey
  activities for both stocks combined.
\5\ Proposed take includes harbor seals, gray seals, and harp seals.

    To inform both the negligible impact analysis and the small numbers 
determination, NMFS assesses the maximum number of takes of marine 
mammals that could occur within any given year. In this calculation, 
the maximum estimated number of Level A harassment takes in any one 
year is summed with the maximum estimated

[[Page 553]]

number of Level B harassment takes in any one year for each species to 
yield the highest number of estimated take that could occur in any year 
(table 25). Table 25 also depicts the number of takes proposed relative 
to the abundance of each stock. The takes enumerated here represent 
daily instances of take, not necessarily individual marine mammals 
taken. One take represents a day in which an animal was exposed to 
noise above the associated harassment threshold at least once. Some 
takes represent a brief exposure above a threshold, while in some cases 
takes could represent a longer, or repeated, exposure of one individual 
animal above a threshold within a 24-hour period. Whether or not every 
take assigned to a species represents a different individual depends on 
the daily and seasonal movement patterns of the species in the area. 
For example, activity areas with continuous activities (all or nearly 
every day) overlapping known feeding areas (where animals are known to 
remain for days or weeks on end) or areas where species with small home 
ranges live (e.g., some pinnipeds) are more likely to result in 
repeated takes to some individuals. Alternatively, activities that are 
not occurring on consecutive days for the duration of the project 
(e.g., foundation installation) or occurring in an area where animals 
are migratory and not expected to remain for multiple days, represent 
circumstances where repeat takes of the same individuals are less 
likely. For example, 100 takes could represent 100 individuals each 
taken on one day within the year, or it could represent 5 individuals 
each taken on 20 days within the year. The combination of number of 
individuals each taken and number of days on which take would occur 
would depend upon the activity, the presence of biologically important 
areas in the project area, and the movement patterns of the marine 
mammal species exposed. Where information to better contextualize the 
enumerated takes for a given species is available, it is discussed in 
the Negligible Impact Analysis and Determination and/or Small Numbers 
sections, as appropriate.

  Table 25--Maximum Number of Proposed Takes (by Level A Harassment and Level B Harassment) That Could Occur in
                        Any One Year of the Project Relative to Stock Population Size \1\
----------------------------------------------------------------------------------------------------------------
                                                                                               Maximum  proposed
                                                          Maximum      Maximum                 take  (instances)
                                            NMFS stock     annual       annual      Maximum      as a percentage
          Marine mammal species             abundance     Level A      Level B    annual take       of stock
                                                         harassment   harassment                 abundance) 1 2
 
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale 3 4...........          338            0            4            4               1.18
Fin whale 3 4............................        6,802            2           18           20               0.29
Humpback whale \4\.......................        1,396            2           16           18               1.29
Minke whale..............................       21,968            6           41           47               0.21
Sei whale 3 4............................        6,292            1            1            2               0.03
Killer whale \4\.........................          UNK            0            3            3                UNK
Atlantic spotted dolphin \4\.............       39,921            0           69           69               0.17
Coastal bottlenose dolphin \5\...........        6,639            0        1,591        1,591               24.0
Offshore bottlenose dolphin \5\..........       62,851            0        1,768        1,768               2.81
Common dolphin...........................      172,974            0          298          298               0.17
Long-finned pilot whale \4\..............       39,215            0           16           16               0.04
Short-finned pilot whale \4\.............       28,924            0           11           11               0.04
Pantropical spotted dolphin \4\..........        6,593            0            5            5               0.08
Risso's dolphin \4\......................       35,215            0           26           26               0.07
Rough-toothed dolphin \4\................          136            0            6            6               4.41
Striped dolphin \4\......................       67,036            0           46           46               0.07
Harbor porpoise \4\......................       95,543            3           39           42               0.04
Gray seal \6\............................       27,300            0          341          341               1.25
Harbor seal \6\..........................       61,336                                                      0.56
Harp seal \6\............................         7.6M                                                    0.0004
----------------------------------------------------------------------------------------------------------------
\1\ Year 2 (2026) represents the most impactful year overall.
\2\ The values in this column represent the assumption that each take proposed to be authorized would occur to a
  unique individual. Given the scope of work proposed, this is highly unlikely for species common to the project
  area (e.g., North Atlantic right whales, humpback whales) such that the actual percentage of the population
  taken is less than the percentages identified here.
\3\ Listed as Endangered under the ESA.
\4\ Proposed take is based on average group size.
\5\ Maximum proposed take for each bottlenose dolphin species includes the maximum proposed take by Level B
  harassment of any year for HRG surveys.
\6\ Assumes 100 percent of the take by Level B harassment is from either the gray seal stock, harbor seal stock,
  or harp seal stock.

Proposed Mitigation

    In order to promulgate a rulemaking under section 101(a)(5)(A) of 
the MMPA, NMFS must set forth the permissible methods of taking 
pursuant to the activity, and other means of effecting the least 
practicable adverse impact on the species or stock and its habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance, and on the availability of the species or stock 
for taking for certain subsistence uses (latter not applicable for this 
action). NMFS' regulations require applicants for incidental take 
authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting the activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks and 
their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is

[[Page 554]]

expected to reduce impacts to marine mammals, marine mammal species or 
stocks, and their habitat. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope, range). It further 
considers the likelihood that the measure will be effective if 
implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned); and,
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The mitigation strategies described below are consistent with those 
required and successfully implemented under previous incidental take 
authorizations issued in association with in-water construction 
activities (e.g., soft-start, establishing shutdown zones). Additional 
measures have also been incorporated to account for the fact that the 
proposed construction activities would occur offshore. Modeling was 
performed to estimate harassment zones, which were used to inform 
mitigation measures for the Project's activities to minimize Level A 
harassment and Level B harassment to the extent practicable, while 
providing estimates of the areas within which Level B harassment might 
occur.
    Generally speaking, the mitigation measures considered and proposed 
to be required here fall into three categories: temporal (seasonal and 
daily) work restrictions, real-time measures (shutdown, clearance, and 
vessel strike avoidance), and noise attenuation/reduction measures. 
Seasonal work restrictions are designed to avoid or minimize operations 
when marine mammals are concentrated or engaged in behaviors that make 
them more susceptible or make impacts more likely, in order to reduce 
both the number and severity of potential takes and are effective in 
reducing both chronic (longer-term) and acute effects. Real-time 
measures, such as implementation of shutdown and clearance zones, as 
well as vessel strike avoidance measures, are intended to reduce the 
probability or severity of harassment by taking steps in real time once 
a higher-risk scenario is identified (e.g., once animals are detected 
within an impact zone). Noise attenuation measures, such as bubble 
curtains, are intended to reduce the noise at the source, which reduces 
both acute impacts, as well as the contribution to aggregate and 
cumulative noise that may result in longer-term chronic impacts.
    Below, we briefly describe the required training, coordination, and 
vessel strike avoidance measures that apply to all activity types, and 
then in the following subsections we describe the measures that apply 
specifically to foundation installation, nearshore installation and 
removal activities for cable laying, and HRG surveys. Details on 
specific requirements can be found in Part 217--Regulations Governing 
The Taking And Importing Of Marine Mammals at the end of this proposed 
rulemaking.

Training and Coordination

    NMFS requires all US Wind's employees and contractors conducting 
activities on the water, including, but not limited to, all vessel 
captains and crew, to be trained in marine mammal detection and 
identification, communication protocols, and all required measures to 
minimize impacts on marine mammals and support US Wind's compliance 
with the LOA, if issued. Additionally, all relevant personnel and the 
marine mammal species monitoring team(s) are required to participate in 
joint, onboard briefings prior to the beginning of project activities. 
The briefing must be repeated whenever new relevant personnel (e.g., 
new PSOs, construction contractors, relevant crew) join the project 
before work commences. During this training, US Wind is required to 
instruct all project personnel regarding the authority of the marine 
mammal monitoring team(s). For example, the HRG acoustic equipment 
operator, pile driving personnel, etc., are required to immediately 
comply with any call for a delay or shut down by the Lead PSO. Any 
disagreement between the Lead PSO and the project personnel must only 
be discussed after delay or shutdown has occurred. In particular, all 
captains and vessel crew must be trained in marine mammal detection and 
vessel strike avoidance measures to ensure marine mammals are not 
struck by any project or project-related vessel.
    Prior to the start of in-water construction activities, vessel 
operators and crews would receive training about marine mammals and 
other protected species known or with the potential to occur in the 
Project Area, making observations in all weather conditions, and vessel 
strike avoidance measures. In addition, training would include 
information and resources available regarding applicable Federal laws 
and regulations for protected species. US Wind will provide 
documentation of training to NMFS.

North Atlantic Right Whale Awareness Monitoring

    US Wind would be required to use available sources of information 
on North Atlantic right whale presence, including daily monitoring of 
the Right Whale Sightings Advisory System, monitoring of U.S. Coast 
Guard very high-frequency (VHF) Channel 16 throughout each day to 
receive notifications of any sightings, and information associated with 
any regulatory management actions (e.g., establishment of a zone 
identifying the need to reduce vessel speeds). Maintaining daily 
awareness and coordination affords increased protection of North 
Atlantic right whales by understanding North Atlantic right whale 
presence in the area through ongoing visual and passive acoustic 
monitoring efforts and opportunities (outside of US Wind's efforts), 
and allows for planning of construction activities, when practicable, 
to minimize potential impacts on North Atlantic right whales.

Vessel Strike Avoidance Measures

    This proposed rule contains numerous vessel strike avoidance 
measures that reduce the risk that a vessel and marine mammal could 
collide. While the likelihood of a vessel strike is generally low, they 
are one of the most common ways that marine mammals are seriously 
injured or killed by human activities. Therefore, enhanced mitigation 
and monitoring measures are required to avoid vessel strikes, to the 
extent practicable. While many of these measures are proactive, 
intending to avoid the heavy use of vessels during times when marine 
mammals of particular concern may be in the area, several are reactive 
and occur when a project personnel sights a marine mammal. The 
mitigation requirements we propose are described generally here and in 
detail in the regulation text at the end of this proposed rule (see 50 
CFR 217.264(b)). US Wind would be required to comply with these 
measures except under circumstances when doing so would create an 
imminent and serious threat to a person or vessel or to the extent that 
a vessel is unable to maneuver and, because of the inability to 
maneuver, the vessel cannot comply.
    While underway, US Wind's personnel would be required to monitor 
for and maintain a minimum separation distance from marine mammals and 
operate vessels in a manner that reduces the potential for vessel 
strike.

[[Page 555]]

Regardless of the vessel's size, all vessel operators, crews, and 
dedicated visual observers (i.e., PSO or trained crew member) must 
maintain a vigilant watch for all marine mammals and slow down, stop 
their vessel, or alter course (as appropriate) to avoid striking any 
marine mammal. The dedicated visual observer, equipped with suitable 
monitoring technology (e.g., binoculars, night vision devices), must be 
located at an appropriate vantage point for ensuring vessels are 
maintaining required vessel separation distances from marine mammals 
(e.g., 500 m from North Atlantic right whales).
    All project vessels, regardless of size, must maintain the 
following minimum separation zones: 500 m from North Atlantic right 
whales; 100 m from sperm whales and non-North Atlantic right whale 
baleen whales; and 50 m from all delphinid cetaceans and pinnipeds (an 
exception is made for those species that approach the vessel such as 
bow-riding dolphins) (table 26). All reasonable steps must be taken to 
not violate minimum separation distances. If any of these species are 
sighted within their respective minimum separation zone, the underway 
vessel must shift its engine to neutral (if safe to do so) and the 
engines must not be engaged until the animal(s) have been observed to 
be outside of the vessel's path and beyond the respective minimum 
separation zone. If a North Atlantic right whale is observed at any 
distance by any project personnel or acoustically detected, project 
vessels must reduce speeds to 10 kn. Additionally, in the event that 
any project-related vessel, regardless of size, observes any large 
whale (other than a North Atlantic right whale) within 500 m of an 
underway vessel, the vessel is required to immediately reduce speeds to 
10 kn or less. The 10 kn speed restriction will remain in effect as 
outlined in 50 CFR 217.344(b).

         Table 26--HRG Vessel Strike Avoidance Separation Zones
------------------------------------------------------------------------
                                                  Vessel separation zone
             Marine mammal species                         (m)
------------------------------------------------------------------------
North Atlantic right whale.....................                      500
Other ESA-listed species and large whales......                      100
Other marine mammals \1\.......................                       50
------------------------------------------------------------------------
\1\ With the exception of seals and delphinid(s) from the genera
  Delphinus, Lagenorhynchus, Stenella or Tursiops, as described below.

    All of the project-related vessels would be required to comply with 
existing NMFS vessel speed restrictions for North Atlantic right whales 
and the measures within this rulemaking for operating vessels around 
North Atlantic right whales and other marine mammals. When NMFS vessel 
speed restrictions are not in effect and a vessel is traveling at 
greater than 10 kn, in addition to the required dedicated visual 
observer, US Wind would be required to monitor the crew transfer vessel 
transit corridor (the path crew transfer vessels take from port to any 
work area) in real-time with PAM prior to and during transits. To 
maintain awareness of North Atlantic right whale presence, vessel 
operators, crew members, and the marine mammal monitoring team will 
monitor U.S. Coast Guard VHF Channel 16, WhaleAlert, the Right Whale 
Sighting Advisory System (RWSAS), and the PAM system. Any marine mammal 
observed by project personnel must be immediately communicated to any 
on-duty PSOs, PAM operator(s), and all vessel captains. Any North 
Atlantic right whale or large whale observation or acoustic detection 
by PSOs or PAM operators must be conveyed to all vessel captains. All 
vessels would be equipped with an AIS and US Wind must report all 
Maritime Mobile Service Identity (MMSI) numbers to NMFS Office of 
Protected Resources prior to initiating in-water activities. US Wind 
will submit a NMFS-approved North Atlantic Right Whale Vessel Strike 
Avoidance Plan at least 90 days prior to commencement of vessel use.
    US Wind's compliance with these proposed measures would reduce the 
likelihood of vessel strike to the extent practicable. These measures 
increase awareness of marine mammals in the vicinity of project vessels 
and require project vessels to reduce speed when marine mammals are 
detected (by PSOs, PAM, and/or through another source, e.g., RWSAS) and 
maintain separation distances when marine mammals are encountered. 
While visual monitoring is useful, reducing vessel speed is one of the 
most effective, feasible options available to reduce the likelihood of 
and effects from a vessel strike. Numerous studies have indicated that 
slowing the speed of vessels reduces the risk of lethal vessel 
collisions, particularly in areas where right whales are abundant and 
vessel traffic is common and otherwise traveling at high speeds 
(Vanderlaan and Taggart, 2007; Conn and Silber, 2013; Van der Hoop et 
al., 2014; Martin et al., 2015; Crum et al., 2019).

Seasonal and Daily Restrictions

    Temporal restrictions in places where marine mammals are 
concentrated, engaged in biologically important behaviors, and/or 
present in sensitive life stages are effective measures for reducing 
the magnitude and severity of human impacts. The temporal restrictions 
required here are built around North Atlantic right whale protection. 
Based upon the best scientific information available (Roberts et al., 
2023), the highest densities of North Atlantic right whales in the 
specified geographic region are expected during the months of January 
through April, with an increase in density starting in December. 
However, North Atlantic right whales may be present in the specified 
geographic region throughout the year.
    NMFS is proposing to require seasonal work restrictions to minimize 
risk of noise exposure to the North Atlantic right whales incidental to 
certain specified activities to the extent practicable. These seasonal 
work restrictions are expected to greatly reduce the number of takes of 
North Atlantic right whales. These seasonal restrictions also afford 
protection to other marine mammals that are known to use the Project 
Area with greater frequency during winter months, including other 
baleen whales.
    As described previously, no impact pile driving activities may 
occur December 1 through April 30. NMFS is not proposing any seasonal 
restrictions to HRG surveys; however, US Wind has planned a limited 
amount of surveys (over 14 days) during daylight within the proposed 
effective period of these regulations.
    NMFS is also proposing temporal restrictions for some activities. 
Within any 24-hour period, NMFS proposes to limit installing up to one 
monopile foundation or four 3-m pin piles during daylight hours only 
unless US Wind requests to install additional piles per

[[Page 556]]

day in order to complete construction more quickly, provided the 
modeling information necessary to adaptively manage mitigation zone 
sizes as well as information identifying the change to the pile driving 
schedule would not result in more take (annual or 5-year total) than 
analyzed in the final rule or authorized in any associated LOA, and 
such request is approved by NMFS. US Wind does not plan to initiate 
pile driving later than 1.5 hours after civil sunset or continue pile 
driving after or1 hour before civil sunrise. However, if US Wind 
determines that they may initiate pile driving after the aforementioned 
time frame, they must submit a sufficient nighttime pile driving plan 
for NMFS review and approval to do so. A sufficient nighttime pile 
driving plan would demonstrate that proposed detection systems would be 
capable of detecting marine mammals, particularly large whales, at 
distances necessary to ensure mitigation measures are effective. US 
Wind would also be encouraged to investigate and test advanced 
technology to support their request. NMFS proposes to condition the LOA 
such that nighttime pile driving would only be allowed if US Wind 
submitted an Alternative Monitoring Plan to NMFS for approval that 
proved the efficacy of their night vision devices (e.g., mounted 
thermal/infrared (IR) camera systems, hand-held or wearable night 
vision devices (NVDs), IR spotlights) in detecting protected marine 
mammals. If the plan did not include a full description of the proposed 
technology, monitoring methodology, and data supporting that marine 
mammals could reliably and effectively be detected within the clearance 
and shutdown zones for monopiles and pin piles before and during impact 
pile driving, nighttime pile driving (unless a pile was initiated 1.5 
hours prior to civil sunset) would not be allowed. The Plan should 
identify the efficacy of the technology at detecting marine mammals in 
the clearance and shutdown zones under all of the various conditions 
anticipated during construction, including varying weather conditions, 
sea states, and in consideration of the use of artificial lighting. 
Given the very small Level B harassment zone associated with HRG survey 
activities and no anticipated or authorized Level A harassment, NMFS is 
not proposing any daily restrictions for HRG surveys.
    More information on activity-specific seasonal and daily 
restrictions can be found in the regulatory text at the end of this 
proposed rulemaking.

Noise Attenuation Systems

    US Wind would be required to employ noise abatement systems (NAS), 
also known as noise attenuation systems, during all foundation 
installation (i.e., impact pile driving) activities to reduce the sound 
pressure levels that are transmitted through the water in an effort to 
reduce acoustic ranges to the Level A harassment and Level B harassment 
acoustic thresholds and minimize, to the extent practicable, any 
acoustic impacts resulting from these activities. US Wind would be 
required to use at least two NAS to ensure that measured sound levels 
do not exceed the levels modeled for a 10-dB sound level reduction for 
foundation installation, which is likely to include a double big bubble 
curtain combined with another NAS (other available NAS technologies are 
the hydro-sound damper, or an AdBm Helmholz resonator), as well as the 
adjustment of operational protocols to minimize noise levels. A single 
bubble curtain, alone or in combination with another NAS device, may 
not be used for pile driving as received SFV data reveals this approach 
is unlikely to attenuate sound sufficiently to be consistent with the 
modeling underlying our take analysis here, which incorporates expected 
ranges to the Level A and Level B harassment isopleths assuming 10 dB 
of attenuation and appropriate NAS use. Should the research and 
development phase of newer systems demonstrate effectiveness, as part 
of adaptive management, US Wind may submit data on the effectiveness of 
these systems and request approval from NMFS to use them during 
foundation installation activities.
    Two categories of NAS exist: primary and secondary. A primary NAS 
would be used to reduce the level of noise produced by foundation 
installation activities at the source, typically through adjustments to 
the equipment (e.g., hammer strike parameters). Primary NAS are still 
evolving and will be considered for use during mitigation efforts when 
the NAS has been demonstrated as effective in commercial projects. 
However, as primary NAS are not fully effective at eliminating noise, a 
secondary NAS would be employed. The secondary NAS is a device or group 
of devices that would reduce noise as it was transmitted through the 
water away from the pile, typically through a physical barrier that 
would reflect or absorb sound waves and, therefore, reduce the distance 
the higher energy sound propagates through the water column. Together, 
these systems must reduce noise levels to those not exceeding modeled 
ranges to Level A harassment and Level B harassment isopleths 
corresponding to those modeled assuming 10-dB sound attenuation, 
pending results of SFV (see Sound Field Verification section below and 
Part 217--Regulations Governing The Taking And Importing Of Marine 
Mammals).
    Noise abatement systems, such as bubble curtains, are used to 
decrease the sound levels radiated from a source. Bubbles create a 
local impedance change that acts as a barrier to sound transmission. 
The size of the bubbles determines their effective frequency band, with 
larger bubbles needed for lower frequencies. There are a variety of 
bubble curtain systems, confined or unconfined bubbles, and some with 
encapsulated bubbles or panels. Attenuation levels also vary by type of 
system, frequency band, and location. Small bubble curtains have been 
measured to reduce sound levels, but effective attenuation is highly 
dependent on depth of water, current, and configuration and operation 
of the curtain (Austin et al., 2016; Koschinski and L[uuml]demann, 
2013). Bubble curtains vary in terms of the sizes of the bubbles and 
those with larger bubbles tend to perform a bit better and more 
reliably, particularly when deployed with two separate rings (Bellmann, 
2014; Koschinski and L[uuml]demann, 2013; Nehls et al., 2016). 
Encapsulated bubble systems (i.e., Hydro Sound Dampers (HSDs)), can be 
effective within their targeted frequency ranges (e.g., 100-800 Hz), 
and when used in conjunction with a bubble curtain appear to create the 
greatest attenuation. The literature presents a wide array of observed 
attenuation results for bubble curtains. The variability in attenuation 
levels is the result of variation in design as well as differences in 
site conditions and difficulty in properly installing and operating in-
water attenuation devices.
    For example, D[auml]hne et al. (2017) found that single bubble 
curtains that reduce sound levels by 7 to 10 dB reduced the overall 
sound level by approximately 12 dB when combined as a double bubble 
curtain for 6-m steel monopiles in the North Sea. During installation 
of monopiles (consisting of approximately 8-m in diameter) for more 
than 150 WTGs in comparable water depths (>25 m) and conditions in 
Europe indicate that attenuation of 10 dB is readily achieved 
(Bellmann, 2019; Bellmann et al., 2020) using single big bubble 
curtains (BBCs) for noise attenuation. When a double big bubble curtain 
is used (noting a single bubble curtain is not allowed), US Wind would 
be required to maintain numerous

[[Page 557]]

operational performance standards. These standards are defined in the 
regulatory text at the end of this proposed rulemaking and include but 
are not limited to construction contractors must train personnel in the 
proposed balancing of airflow to the bubble ring and US Wind would be 
required to submit a performance test and maintenance report to NMFS 
within 72 hours following the performance test. Corrections to the 
attenuation device to meet regulatory requirements must occur prior to 
use during foundation installation activities. In addition, a full 
maintenance check (e.g., manually clearing holes) must occur prior to 
each pile being installed. If US Wind uses a noise mitigation device in 
addition to a double big bubble curtain, similar quality control 
measures are required.
    US Wind would be required to conduct SFV and submit an SFV plan to 
NMFS for approval at least 180 days prior to installing foundations. 
They would also be required to submit interim and final SFV data 
results to NMFS and make corrections to the noise attenuation systems 
in the case that any SFV measurements demonstrate noise levels are 
above those modeled assuming 10 dB of attenuation. These frequent and 
immediate reports would allow NMFS to better understand the sound 
fields to which marine mammals are being exposed and require immediate 
corrective action should they be misaligned with anticipated noise 
levels within our analysis.
    Noise abatement devices are not required during HRG surveys. NAS 
cannot practicably be employed around a moving survey ship, but US Wind 
would be required to make efforts to minimize source levels by using 
the lowest energy settings on equipment that has the potential to 
result in harassment of marine mammals (e.g., sparkers, boomers) and 
turn off equipment when not actively surveying. Overall, minimizing the 
amount and duration of noise in the ocean from any of the project's 
activities through use of all means necessary (e.g., noise abatement, 
turning off power) will effect the least practicable adverse impact on 
marine mammals.

Clearance and Shutdown Zones

    NMFS is proposing to require the establishment of both clearance 
and shutdown zones during project activities that have the potential to 
result in harassment of marine mammals. The purpose of ``clearance'' of 
a particular zone is to minimize potential instances of auditory injury 
and more severe behavioral disturbances by delaying the commencement of 
an activity if marine mammals are near the activity. The purpose of a 
shutdown is to prevent a specific acute impact, such as auditory injury 
or severe behavioral disturbance of sensitive species, by halting the 
activity.
    All relevant clearance and shutdown zones during project activities 
would be monitored by NMFS-approved PSOs and/or PAM operators (as 
described in the regulatory text at the end of this proposed 
rulemaking). At least one PAM operator must review data from at least 
24 hours prior to foundation installation and actively monitor 
hydrophones for 60 minutes prior to commencement of these activities. 
Any sighting or acoustic detection of a North Atlantic right whale 
triggers a delay to commencing pile driving and shutdown.
    Prior to the start of certain specified activities (foundation 
installation and HRG surveys), US Wind would be required to ensure 
designated areas (i.e., clearance zones, tables 26, 27, and 28) are 
clear of marine mammals prior to commencing activities to minimize the 
potential for and degree of harassment. For foundation installation, 
PSOs must visually monitor clearance zones for marine mammals for a 
minimum of 60 minutes, where the zone must be confirmed free of marine 
mammals at least 30 minutes directly prior to commencing these 
activities. For monopile foundation installation, the minimum 
visibility zone, defined as the area over which PSOs must be able to 
visually detect marine mammals, would extend 2,900 m (9,514 ft) for 
monopile installation, 1,400 m for 3-m pin pile installation, and 200 m 
for 1.8-m pin pile installation (table 26). Clearance zones are defined 
and provided in table 26 for all species.
    For any other in-water construction heavy machinery activities 
(e.g., trenching, cable laying, etc.), if a marine mammal is on a path 
towards or comes within 10 m (32.8 ft) of equipment, US Wind would be 
required to cease operations until the marine mammal has moved more 
than 10 m on a path away from the activity to avoid direct interaction 
with equipment.
    Once an activity begins, any marine mammal entering their 
respective shutdown zone would trigger the activity to cease. In the 
case of pile driving, the shutdown requirement may be waived if is not 
practicable due to imminent risk of injury or loss of life to an 
individual or risk of damage to a vessel that creates risk of injury or 
loss of life for individuals, or if the lead engineer determines there 
is pile refusal or pile instability.
    In situations when shutdown is called for, but US Wind determines 
shutdown is not practicable due to aforementioned emergency reasons, 
reduced hammer energy must be implemented when the lead engineer 
determines it is practicable. Specifically, pile refusal or pile 
instability could result in not being able to shut down pile driving 
immediately. Pile refusal occurs when the pile driving sensors indicate 
the pile is approaching refusal, and a shut-down would lead to a stuck 
pile which then poses an imminent risk of injury or loss of life to an 
individual, or risk of damage to a vessel that creates risk for 
individuals. Pile instability occurs when the pile is unstable and 
unable to stay standing if the piling vessel were to ``let go.'' During 
these periods of instability, the lead engineer may determine a shut-
down is not feasible because the shut-down combined with impending 
weather conditions may require the piling vessel to ``let go'' which 
then poses an imminent risk of injury or loss of life to an individual, 
or risk of damage to a vessel that creates risk for individuals. US 
Wind must document and report to NMFS all cases where the emergency 
exemption is taken.
    After shutdown, impact pile driving may be reinitiated once all 
clearance zones are clear of marine mammals for the minimum species-
specific periods, or, if required to maintain pile stability, impact 
pile driving may be reinitiated but must be used to maintain stability. 
If pile driving has been shut down due to the presence of a North 
Atlantic right whale, pile driving must not restart until the North 
Atlantic right whale has not been visually or acoustically detected for 
30 minutes. Upon re-starting pile driving, soft-start protocols must be 
followed if pile driving has ceased for 30 minutes or longer.
    The clearance and shutdown zone sizes vary by species and are shown 
in tables 27 and 28. US Wind would be allowed to request modification 
to these zone sizes pending results of sound field verification (see 
regulatory text at the end of this proposed rulemaking). Any changes to 
zone size would be part of adaptive management and would require NMFS' 
approval.

[[Page 558]]



        Table 27--Minimum Visibility, Clearance, Shutdown, and Level B Harassment Zones During Impact Pile Driving, Assuming 10 dB of Attenuation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      North Atlantic  right                          Delphinids and  pilot
          Monitoring zone                    whales            Other large whales            whales            Harbor porpoises            Seals
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minimum Visibility Zone \1\........                                                  Monopiles: 2,900 m.
                                                                                   3-m pin piles: 1,400 m.
                                                                                   1.8-m pin piles: 200 m.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Clearance Zone.....................  Any distance (visual)   Monopiles: 5,250 m....                           Monopiles: 500 m.
                                      or
                                      within PAM Monitoring  3-m pin piles: 1,400 m                         3-m pin piles: 200 m.
                                      Zone.                  1.8-m Pin piles: 200 m                      1.8 m pin piles: 200 m \3\.
                                                              \2\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown Zone......................  Any distance (visual)   Monopiles: 2,900 m....                           Monopiles: 250 m.
                                      or
                                      within PAM Monitoring  3-m pin piles: 1,400 m               3-m pin piles, 1.8-m pin piles: 100 m \5\.
                                      Zone.                  1.8-m Pin piles: 100 m
                                                              \4\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
PAM Monitoring Zone \6\............                                                        10,000 m
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level B Harassment                                                                   Monopiles: 5,250 m.
 (Acoustic Range, R95%)                                                             3-m pin piles: 500 m.
                                                                                   1.8-m pin piles: 100 m.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The minimum visibility zone is equal to the modeled maximum R95 percent distances to the Level A harassment threshold for low-frequency cetaceans
  for monopiles and 3-m pin piles. The minimum visibility zone for 1.8-m pin piles is equal to the clearance zone, which is double the modeled maximum
  R95 percent distance to the Level B harassment threshold (100 m) and four times the modeled maximum R95 percent distance to the Level A harassment
  threshold (50 m) for low-frequency cetaceans. NMFS increased the 1.8-m pin pile minimum visibility zone given the very small zone sizes from this
  short (3 piles total) activity.
\2\ The clearance zone for other large whales from monopile installation is equal to the modeled maximum R95 percent distance to the Level B harassment
  threshold (5,250 m). The clearance zone for other large whales from 3-m pin pile installation is equal to the modeled maximum R95 percent distance to
  the Level A harassment threshold (1,400 m), given the Level B harassment zone (500 m) is less than this distance. The clearance zone for other large
  whales from 1.8-m pin pile installation is equal to twice the modeled maximum R95 percent distance to the Level B harassment threshold given the very
  small Level B harassment zone (100 m), which could be encompassed by the bubble curtains.
\3\ The clearance zone for non-large whales (i.e., delphinids and pilot whales, harbor porpoises, and seals) from monopile and 3-m pin pile installation
  is equal to double the modeled maximum R95 percent distances to the Level A harassment threshold for harbor porpoise (the most sensitive species). The
  clearance zone for 1.8-m pin pile installation is equal to double the modeled maximum R95 percent distance to the Level B harassment threshold given
  Level A harassment thresholds were not exceeded for this activity (i.e., 0 m). US Wind requested the clearance zone for non-large whales be identical
  for PSO implementation ease.
\4\ The shutdown zones for other large whales from monopiles and 3-m pin piles are equal to the modeled maximum R95 percent distances to the Level A
  harassment threshold for low-frequency cetaceans. The shutdown zone for other large whales from 1.8-m pin piles is equal to two times the modeled
  maximum R95 percent distance to the Level A harassment threshold for low-frequency cetaceans.
\5\ The shutdown zones for non-large whales from monopile and 3-m pin pile installation are equal to the modeled maximum R95 percent distances to the
  Level A harassment threshold for harbor porpoise (the most sensitive species). The shutdown zone for non-large whales from 1.8-m pin pile installation
  is equal to the modeled maximum R95 percent distance to the Level B harassment threshold, given the Level A harassment thresholds were not exceeded
  for this activity (i.e., 0 m). US Wind requested the shutdown zone for non-large whales be identical for PSO implementation ease.
\6\ The PAM system must be capable of detecting baleen whales at 10,000 m during pile driving. The system should also be designed to detect other marine
  mammals; however, it is not required these other species be detected out to 10,000 m given higher frequency calls and echolocation clicks are not
  typically detectable at large distances.


            Table 28--HRG Survey Clearance and Shutdown Zones
------------------------------------------------------------------------
                                                 Clearance
             Marine mammal species                  zone       Shutdown
                                                   (m\2\)     zone  (m)
------------------------------------------------------------------------
North Atlantic right whale....................          500          500
Other ESA-listed species (i.e., fin, sei,               500          100
 sperm whale).................................
Other marine mammals \1\......................          200          100
------------------------------------------------------------------------
\1\ With the exception of seals and delphinid(s) from the genera
  Delphinus, Lagenorhynchus, Stenella or Tursiops, as described below.

Soft-Start/Ramp Up

    The use of a soft-start or ramp up procedure is believed to provide 
additional protection to marine mammals by warning them or providing 
them with a chance to leave the area prior to the hammer or HRG 
equipment operating at full capacity. Soft-start typically involves 
initiating hammer operation at a reduced energy level (relative to full 
operating capacity) followed by a waiting period. US Wind would be 
required to utilize a soft-start protocol for impact pile driving of 
monopiles, 3-m pin piles, and 1.8-m pin piles by performing four to six 
strikes per minute at 10 to 20 percent of the maximum hammer energy, 
for a minimum of 20 minutes. NMFS notes that it is difficult to specify 
a reduction in energy for any given hammer because of variation across 
drivers and installation conditions. US Wind will reduce energy based 
on consideration of site-specific soil properties and other relevant 
operational considerations. HRG survey operators would be required to 
ramp-up sources when the acoustic sources are used unless the equipment 
operates on a binary on/off switch. The ramp up would involve starting 
from the smallest setting to the operating level over a period of 
approximately 30 minutes.
    Soft-start and ramp up would be required at the beginning of each 
day's activity and at any time following a cessation of activity of 30 
minutes or longer. Prior to soft-start or ramp up beginning, the 
operator must receive confirmation from the PSO that the clearance zone 
is clear of any marine mammals.

Fishery Monitoring Surveys

    While the likelihood of US Wind's fishery monitoring surveys 
impacting marine mammals is minimal, NMFS proposed to require US Wind 
to adhere to gear and vessel mitigation measures to reduce potential 
impacts to the extent practicable. In addition, all crew undertaking 
the fishery monitoring survey activities would be required to receive 
protected species identification training prior to activities occurring 
and attend the aforementioned onboarding training. The specific 
requirements that NMFS would set for the fishery monitoring surveys can 
be found in the

[[Page 559]]

regulatory text at the end of this proposed rulemaking.
    Based on our evaluation of the mitigation measures, NMFS has 
preliminarily determined that these proposed measures would provide the 
means of affecting 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.

Proposed Monitoring and Reporting

    In order to promulgate a rulemaking for an activity, section 
101(a)(5)(A) of the MMPA states that NMFS must set forth requirements 
pertaining to the monitoring and reporting of such taking. The MMPA 
implementing regulations at 50 CFR 216.104(a)(13) indicate that 
requests for authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present in the proposed action area. Effective reporting is critical 
both to compliance as well as ensuring that the most value is obtained 
from the required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and/or
    <bullet> Mitigation and monitoring effectiveness.
    Separately, monitoring is also regularly used to support mitigation 
implementation, which is referred to as mitigation monitoring, and 
monitoring plans typically include measures that both support 
mitigation implementation and increase our understanding of the impacts 
of the activity on marine mammals.
    During the planned activities, visual monitoring by NMFS-approved 
PSOs would be conducted before, during, and after all impact pile 
driving and HRG surveys. PAM would also be conducted during impact pile 
driving. Visual observations and acoustic detections would be used to 
support the activity-specific mitigation measures (e.g., clearance 
zones). To increase understanding of the impacts of the activity on 
marine mammals, PSOs must record all incidents of marine mammal 
occurrence at any distance from the piling locations, near the HRG 
acoustic sources. PSOs would document all behaviors and behavioral 
changes, in concert with distance from an acoustic source. The required 
monitoring is described below, beginning with PSO measures that are 
applicable to all the aforementioned activities, followed by activity-
specific monitoring requirements.

Protected Species Observer and PAM Operator Requirements

    US Wind would be required to employ NMFS-approved PSOs and PAM 
operators. PSOs are trained professionals who are tasked with visual 
monitoring for marine mammals during pile driving and HRG surveys. The 
primary purpose of a PSO is to carry out the monitoring, collect data, 
and, when appropriate, call for the implementation of mitigation 
measures. In addition to visual observations, NMFS would require US 
Wind to conduct PAM using PAM operators during impact pile driving and 
vessel transit.
    The inclusion of PAM, which would be conducted by NMFS-approved PAM 
operators, following a standardized measurement, processing methods, 
reporting metrics, and metadata standards for offshore wind alongside 
visual data collection is valuable to provide the most accurate record 
of species presence as possible, together with visual monitoring, and 
these two monitoring methods are well understood to provide best 
results when combined together (e.g., Barlow and Taylor, 2005; Clark et 
al., 2010; Gerrodette et al., 2011; Van Parijs et al., 2021). Acoustic 
monitoring (in addition to visual monitoring) increases the likelihood 
of detecting marine mammals within the shutdown and clearance zones of 
project activities, which when applied in combination with required 
shutdowns helps to further reduce the risk of marine mammals being 
exposed to sound levels that could otherwise result in acoustic injury 
or more intense behavioral harassment.
    The exact configuration and number of PAM systems depends on the 
size of the zone(s) being monitored, the amount of noise expected in 
the area, and the characteristics of the signals being monitored. More 
closely spaced hydrophones would allow for more directionality, and 
perhaps, range to the vocalizing marine mammals; although, this 
approach would add additional costs and greater levels of complexity to 
the project. Larger baleen cetacean species (i.e., mysticetes), which 
produce loud and lower-frequency vocalizations, may be able to be heard 
with fewer hydrophones spaced at greater distances. However, smaller 
cetaceans (such as mid-frequency delphinids or odontocetes) may 
necessitate more hydrophones and to be spaced closer together given the 
shorter range of the shorter, mid-frequency acoustic signals (e.g., 
whistles and echolocation clicks). As there are no ``perfect fit'' 
single-optimal-array configurations, NMFS will consider and approve 
these set-ups, as appropriate, on a case-by-case basis. Specifically, 
US Wind will be required to provide a plan that describes an optimal 
configuration for collecting the required marine mammal data, based on 
the real-world circumstances in the project area, recognizing that we 
will continue to learn more as monitoring results from other wind 
projects are submitted.
    NMFS does not formally administer any PSO or PAM operator training 
program or endorse specific providers but will approve PSOs and PAM 
operators that have successfully completed courses that meet the 
curriculum and trainer requirements referenced below and further 
specified in the regulatory text at the end of this proposed 
rulemaking.
    NMFS will provide PSO and PAM operator approvals in the context of 
the need to ensure that PSOs and PAM operators have the necessary 
training and/or experience to carry out their duties competently. In 
order for PSOs and PAM operators to be approved, NMFS must review and 
approve PSO and PAM operator resumes indicating successful completion 
of an acceptable training course. PSOs and PAM operators must have 
previous

[[Page 560]]

experience observing marine mammals and must have the ability to work 
with all required and relevant software and equipment. NMFS may approve 
PSOs and PAM operators as conditional or unconditional. Conditional 
approval may be given to one who is trained but has not yet attained 
the requisite experience. Unconditional approval is given to one who is 
trained and has attained the necessary experience. The specific 
requirements for conditional and unconditional approval can be found in 
the regulatory text at the end of this proposed rulemaking.
    Conditionally approved PSOs and PAM operators would be paired with 
an unconditionally approved PSO (or PAM operator, as appropriate) to 
ensure that the quality of marine mammal observations and data 
recording is kept consistent. Additionally, activities requiring PSO 
and/or PAM operator monitoring must have a lead on duty. The visual PSO 
field team, in conjunction with the PAM team (i.e., marine mammal 
monitoring team) would have a lead member (designated as the ``Lead 
PSO'' or ``Lead PAM operator'') who would be required to meet the 
unconditional approval standard.
    Although PSOs and PAM operators must be approved by NMFS, third-
party observer providers and/or companies seeking PSO and PAM operator 
staffing should expect that those having satisfactorily completed 
acceptable training and with the requisite experience (if required) 
will be quickly approved. US Wind is required to request PSO and PAM 
operator approvals 60 days prior to those personnel commencing work. An 
initial list of previously approved PSO and PAM operators must be 
submitted by US Wind at least 30 days prior to the start of the 
project. Should US Wind require additional PSOs or PAM operators 
throughout the project, US Wind must submit a subsequent list of pre-
approved PSOs and PAM operators to NMFS at least 15 days prior to 
planned use of that PSO or PAM operator. A PSO may be trained and/or 
experienced as both a PSO and PAM operator and may perform either duty, 
pursuant to scheduling requirements (and vice versa).
    A minimum number of PSOs would be required to actively observe for 
the presence of marine mammals during certain project activities with 
more PSOs required as the mitigation zone sizes increase. A minimum 
number of PAM operators would be required to actively monitor for the 
presence of marine mammals during foundation installation. The types of 
equipment required (e.g., Big Eye binoculars on the pile driving 
vessel) are also designed to increase marine mammal detection 
capabilities. Specifics on these types of requirements can be found in 
the regulations at the end of this proposed rulemaking. At least three 
PSOs and one PAM operator per acoustic data stream (equivalent to the 
number of acoustic buoys) must be on-duty and actively monitoring per 
platform during foundation installation; and at least one PSO must be 
on-duty during HRG surveys conducted during daylight hours.
    In addition to monitoring duties, PSOs and PAM operators are 
responsible for data collection. The data collected by PSO and PAM 
operators and subsequent analysis provide the necessary information to 
inform an estimate of the amount of take that occurred during the 
project, better understand the impacts of the project on marine 
mammals, address the effectiveness of monitoring and mitigation 
measures, and to adaptively manage activities and mitigation in the 
future. Data reported includes information on marine mammal sightings, 
activity occurring at time of sighting, monitoring conditions, and if 
mitigative actions were taken. Specific data collection requirements 
are contained within the regulations at the end of this proposed 
rulemaking.
    US Wind would be required to submit a Pile Driving Marine Mammal 
Monitoring Plan to NMFS 180 days in advance of foundation installation 
activities. The Plan must include details regarding PSO and PAM 
monitoring protocols and equipment proposed for use. More specifically, 
the PAM portion of the plan must include a description of all proposed 
PAM equipment, address how the proposed passive acoustic monitoring 
must follow standardized measurement, processing methods, reporting 
metrics, and metadata standards for offshore wind as described in NOAA 
and BOEM Minimum Recommendations for Use of Passive Acoustic Listening 
Systems in Offshore Wind Energy Development Monitoring and Mitigation 
Programs (Van Parijs et al., 2021). NMFS must approve the plan prior to 
the commencement of foundation installation activities. Specific 
details on NMFS' PSO or PAM operator qualifications and requirements 
can be found in Part 217--Regulations Governing The Taking And 
Importing Of Marine Mammals at the end of this proposed rulemaking. 
Additional information can be found in US Wind Marine Mammal Monitoring 
and Mitigation Plan (appendix B) on the NMFS' website at https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-wind-inc-construction-and-operation-maryland-offshore-wind.

Sound Field Verification

    US Wind would be required to conduct SFV measurements during all 
impact pile driving activities associated with the installation of, at 
minimum, the first three monopile foundations. SFV measurements must 
continue until at least three consecutive monopiles and three entire 
jacket foundations demonstrate noise levels are at or below those 
modeled, assuming 10-dB of attenuation. Subsequent SFV measurements 
would also be required should larger piles be installed or if 
additional piles are driven that are anticipated to produce louder 
sound fields than those previously measured (e.g., higher hammer 
energy, greater number of strikes, etc.). The measurements and 
reporting associated with SFV can be found in the regulatory text at 
the end of this proposed rulemaking. The proposed requirements are 
extensive to ensure monitoring is conducted appropriately and the 
reporting frequency is such that US Wind would be required to make 
adjustments quickly (e.g., add additional sound attenuation) to ensure 
marine mammals are not experiencing noise levels above those considered 
in this analysis. For recommended SFV protocols for impact pile 
driving, please consult International Organization for Standardization 
(ISO) 18406 Underwater acoustics--Measurement of radiated underwater 
sound from percussive pile driving (2017).

Reporting

    Prior to any construction activities occurring, US Wind would 
provide a report to NMFS Office of Protected Resources that 
demonstrates that all US Wind personnel, which includes the vessel 
crews, vessel captains, PSOs, and PAM operators have completed all 
required trainings.
    NMFS would require standardized and frequent reporting from US Wind 
during the life of the regulations and LOA. All data collected relating 
to the Project would be recorded using industry-standard software 
(e.g., Mysticetus or a similar software) installed on field laptops 
and/or tablets. US Wind would be required to submit weekly, monthly, 
annual, and situational reports. The specifics of what we require to be 
reported can be found in the regulatory text at the end of this 
proposed rulemaking.

[[Page 561]]

    Weekly Report--During foundation installation activities, US Wind 
would be required to compile and submit weekly marine mammal monitoring 
reports for foundation installation pile driving to NMFS Office of 
Protected Resources that document the daily start and stop of all pile 
driving activities, the start and stop of associated observation 
periods by PSOs, details on the deployment of PSOs, a record of all 
detections of marine mammals (acoustic and visual), any mitigation 
actions (or if mitigation actions could not be taken, provide reasons 
why), and details on the noise abatement system(s) (e.g., system type, 
distance deployed from the pile, bubble rate, etc.). Weekly reports 
will be due on Wednesday for the previous week (Sunday to Saturday). 
The weekly reports are also required to identify which turbines become 
operational and when (a map must be provided). Once all foundation pile 
installation is complete, weekly reports would no longer be required.
    Monthly Report--US Wind would be required to compile and submit 
monthly reports to NMFS Office of Protected Resources that include a 
summary of all information in the weekly reports, including project 
activities carried out in the previous month, vessel transits (number, 
type of vessel, and route), number of piles installed, all detections 
of marine mammals, and any mitigative actions taken. Monthly reports 
would be due on the 15th of the month for the previous month. The 
monthly report would also identify which turbines become operational 
and when (a map must be provided). Once all foundation pile 
installation is complete, monthly reports would no longer be required.
    Annual Reporting--US Wind would be required to submit an annual 
marine mammal monitoring (both PSO and PAM) report to NMFS Office of 
Protected Resources no later than 90 days following the end of a given 
calendar year describing, in detail, all of the information required in 
the monitoring section above. A final annual report must be prepared 
and submitted within 30 calendar days following receipt of any NMFS 
comments on the draft report.
    Final 5-Year Reporting--US Wind would be required to submit its 
draft 5-year report(s) to NMFS Office of Protected Resources on all 
visual and acoustic monitoring conducted under the LOA within 90 
calendar days of the completion of activities occurring under the LOA. 
A final 5-year report must be prepared and submitted within 60 calendar 
days following receipt of any NMFS comments on the draft report. 
Information contained within this report is described at the beginning 
of this section.
    Situational Reporting--Specific situations encountered during the 
development of the Project would require immediate reporting. For 
instance, if a North Atlantic right whale is observed at any time by 
PSOs or project personnel, the sighting must be immediately (if not 
feasible, as soon as possible, and no longer than 24 hours after the 
sighting) reported to NMFS. If a North Atlantic right whale is 
acoustically detected at any time via a project-related PAM system, the 
detection must be reported as soon as possible and no longer than 24 
hours after the detection to NMFS via the 24-hour North Atlantic right 
whale Detection Template (https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates). Calling the 
hotline is not necessary when reporting PAM detections via the 
template.
    If a sighting of a stranded, entangled, injured, or dead marine 
mammal occurs, the sighting would be reported to NMFS Office of 
Protected Resources, the NMFS Greater Atlantic Stranding Coordinator 
for the New England/Mid-Atlantic area (866-755-6622), and the U.S. 
Coast Guard within 24 hours. If the injury or death was caused by a 
project activity, US Wind would be required to immediately cease all 
activities until NMFS Office of Protected Resources is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the LOA. NMFS Office of Protected Resources may impose additional 
measures to minimize the likelihood of further prohibited take and 
ensure MMPA compliance consistent with the adaptive management 
provisions described below and codified at Sec.  217.307. US Wind could 
not resume their activities until notified by NMFS Office of Protected 
Resources.
    In the event of a vessel strike of a marine mammal by any vessel 
associated with the Project, US Wind must immediately report the strike 
incident. If the strike occurs in the Greater Atlantic Region (Maine to 
Virginia), US Wind must call the NMFS Office of Protected Resources and 
GARFO. US Wind would be required to immediately cease all on-water 
activities until NMFS Office of Protected Resources is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the LOA. NMFS Office of Protected Resources may impose additional 
measures to minimize the likelihood of further prohibited take and 
ensure MMPA compliance. US Wind may, consistent with the adaptive 
management provisions described below and codified at Sec.  217.307, 
not resume their activities until notified by NMFS.
    In the event of any lost gear associated with the fishery surveys, 
US Wind must report to the GARFO as soon as possible or within 24 hours 
of the documented time of missing or lost gear. This report must 
include information on any markings on the gear and any efforts 
undertaken or planned to recover the gear.
    The specifics of what NMFS Office of Protected Resources requires 
to be reported is listed at the end of this proposed rulemaking in the 
regulatory text.
    Sound Field Verification--US Wind would be required to submit 
interim SFV reports after each foundation installation within 48 hours. 
A final SFV report for all monopile, jacket foundation, and pin pile 
installation monitoring would be required within 90 days following 
completion of acoustic monitoring.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
US Wind construction activities contain an adaptive management 
component. Our understanding of the effects of offshore wind 
construction activities (e.g., acoustic stressors) on marine mammals 
continues to evolve, which makes the inclusion of an adaptive 
management component both valuable and necessary within the context of 
5-year regulations.
    The monitoring and reporting requirements in this final rule 
provide NMFS with information that helps us to better understand the 
impacts of the project's activities on marine mammals and informs our 
consideration of whether any changes to mitigation and monitoring are 
appropriate. The use of adaptive management allows NMFS to consider new 
information and modify mitigation, monitoring, or reporting 
requirements, as appropriate, with input from US Wind regarding 
practicability, if such modifications will have a reasonable likelihood 
of more effectively accomplishing the goal of the measures.
    The following are some of the possible sources of new information 
to be considered through the adaptive management process: (1) results 
from monitoring reports, including the weekly, monthly, situational, 
and annual reports required; (2) results from marine mammal and sound 
research; and (3) any information which reveals

[[Page 562]]

that marine mammals may have been taken in a manner, extent, or number 
not authorized by these regulations or subsequent LOA. During the 
course of the rule, US Wind (and other LOA Holders conducting offshore 
wind development activities) are required to participate in one or more 
adaptive management meetings convened by NMFS and/or BOEM, in which the 
above information will be summarized and discussed in the context of 
potential changes to the mitigation or monitoring measures.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' by mortality, serious injury, Level A harassment and Level B 
harassment, we consider other factors, such as the likely nature of any 
behavioral responses (e.g., intensity, duration), the context of any 
such responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338, September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    In the Estimated Take section, we estimated the maximum number of 
takes by Level A harassment and Level B harassment that could occur 
from US Wind's specified activities based on the methods described. The 
impact that any given take would have is dependent on many case-
specific factors that need to be considered in the negligible impact 
analysis (e.g., the context of behavioral exposures such as duration or 
intensity of a disturbance, the health of impacted animals, the status 
of a species that incurs fitness-level impacts to individuals, etc.). 
In this proposed rule, we evaluate the likely impacts of the enumerated 
harassment takes that are proposed to be authorized in the context of 
the specific circumstances surrounding these predicted takes. We also 
collectively evaluate this information, as well as other more taxa-
specific information and mitigation measure effectiveness, in group-
specific discussions that support our negligible impact conclusions for 
each stock. As described above, no serious injury or mortality is 
expected or proposed to be authorized for any species or stock.
    The Description of the Specified Activities section describes US 
Wind specified activities proposed for the project that may result in 
take of marine mammals and an estimated schedule for conducting those 
activities. US Wind has provided a realistic construction schedule 
although we recognize schedules may shift for a variety of reasons 
(e.g., weather or supply delays). However, the total amount of take 
would not exceed the 3-year totals and maximum annual total in any 
given year indicated in tables 24 and 25, respectively.
    We base our analysis and preliminary negligible impact 
determination on the maximum number of takes that could occur and are 
proposed to be authorized annually and across the effective period of 
these regulations, and extensive qualitative consideration of other 
contextual factors that influence the degree of impact of the takes on 
the affected individuals and the number and context of the individuals 
affected. As stated before, the number of takes, both maximum annual 
and 5-year total, alone are only a part of the analysis.
    To avoid repetition, we provide some general analysis in this 
Negligible Impact Analysis and Determination section that applies to 
all the species listed in table 6 given that some of the anticipated 
effects of US Wind's construction activities on marine mammals are 
expected to be relatively similar in nature. Then, we subdivide into 
more detailed discussions for mysticetes, odontocetes, and pinnipeds 
which have broad life history traits that support an overarching 
discussion of some factors considered within the analysis for those 
groups (e.g., habitat-use patterns, high-level differences in feeding 
strategies).
    Last, we provide a negligible impact determination for each species 
or stock, providing species or stock-specific information or analysis, 
where appropriate, for example, for North Atlantic right whales given 
the population status. Organizing our analysis by grouping species or 
stocks that share common traits or that would respond similarly to 
effects of US Wind's activities, and then providing species- or stock-
specific information allows us to avoid duplication while ensuring that 
we have analyzed the effects of the specified activities on each 
affected species or stock. It is important to note that in the group or 
species sections, we base our negligible impact analysis on the maximum 
annual take that is predicted under the 5-year rule; however, the 
majority of the impacts are associated with WTG, Met tower, and OSS 
foundation installation, which are schedule to occur within the first 1 
to 3 years (2025 through 2027) (tables 23, 24, and 25).
    As described previously, no serious injury or mortality is 
anticipated or proposed to be authorized in this rule. Any Level A 
harassment proposed to be authorized would be in the form of auditory 
injury (i.e., PTS) and not non-auditory injury (e.g., lung injury or 
gastrointestinal injury from detonations). The amount of harassment US 
Wind has requested, and NMFS proposes to authorize, is based on 
exposure models that consider the outputs of acoustic source and 
propagation models and other data such as frequency of occurrence or 
group sizes. Several conservative parameters and assumptions are 
ingrained into these models, modeling the impact installation of all 
piles at a maximum hammer energy and application of the May sound speed 
profile to all months within a given season. The exposure model results 
do not reflect any mitigation measures (other than 10-dB sound 
attenuation) or avoidance response. The amount of take requested and 
proposed to be authorized also reflects careful consideration of other 
data (e.g., group size data) and, for Level A harassment potential of 
some large whales, the consideration of mitigation measures. For all 
species, the amount of take proposed to be authorized represents the 
maximum amount of Level A harassment and Level B harassment that could 
occur.

Behavioral Disturbance

    In general, NMFS anticipates that impacts on an individual that has 
been harassed are likely to be more intense when exposed to higher 
received levels and for a longer duration (though this is in no way a 
strictly linear relationship for behavioral effects across species, 
individuals, or circumstances) and less severe impacts result when 
exposed to lower received levels and for a brief

[[Page 563]]

duration. However, there is also growing evidence of the importance of 
contextual factors such as distance from a source in predicting marine 
mammal behavioral response to sound--i.e., sounds of a similar level 
emanating from a more distant source have been shown to be less likely 
to evoke a response of equal magnitude (DeRuiter and Doukara, 2012; 
Falcone et al., 2017). As described in the Potential Effects of 
Specified Activities on Marine Mammals and their Habitat section, the 
intensity and duration of any impact resulting from exposure to US 
Wind's activities is dependent upon a number of contextual factors 
including, but not limited to, sound source frequencies, whether the 
sound source is moving towards the animal, hearing ranges of marine 
mammals, behavioral state at time of exposure, status of individual 
exposed (e.g., reproductive status, age class, health) and an 
individual's experience with similar sound sources. Southall et al. 
(2021), Ellison et al. (2012) and Moore and Barlow (2013), among 
others, emphasize the importance of context (e.g., behavioral state of 
the animals, distance from the sound source) in evaluating behavioral 
responses of marine mammals to acoustic sources. Harassment of marine 
mammals may result in behavioral modifications (e.g., avoidance, 
temporary cessation of foraging or communicating, changes in 
respiration or group dynamics, masking) or may result in auditory 
impacts such as hearing loss. In addition, some of the lower-level 
physiological stress responses (e.g., change in respiration, change in 
heart rate) discussed previously would likely co-occur with the 
behavioral modifications, although these physiological responses are 
more difficult to detect, and fewer data exist relating these responses 
to specific received levels of sound. Take by Level B harassment, then, 
may have a stress-related physiological component as well; however, we 
would not expect US Wind's activities to produce conditions of long-
term and continuous exposure to noise leading to long-term 
physiological stress responses in marine mammals that could affect 
reproduction or survival.
    In the range of behavioral effects that might be expected to be 
part of a response that qualifies as an instance of Level B harassment 
by behavioral disturbance (which by nature of the way it is modeled/
counted, occurs within 1 day), the less severe end might include 
exposure to comparatively lower levels of a sound, at a greater 
distance from the animal, for a few or several minutes. A less severe 
exposure of this nature could result in a behavioral response such as 
avoiding an area that an animal would otherwise have chosen to move 
through or feed in for some amount of time or breaking off one or a few 
feeding bouts. More severe effects could occur if an animal gets close 
enough to the source to receive a comparatively higher level, is 
exposed continuously to one source for a longer time or is exposed 
intermittently to different sources throughout a day. Such effects 
might result in an animal having a more severe flight response and 
leaving a larger area for a day or more or potentially losing feeding 
opportunities for a day. However, such severe behavioral effects are 
expected to occur infrequently.
    Many species perform vital functions, such as feeding, resting, 
traveling, and socializing on a diel cycle (24-hour cycle). Behavioral 
reactions to noise exposure, when taking place in a biologically 
important context, such as disruption of critical life functions, 
displacement, or avoidance of important habitat, are more likely to be 
significant if they last more than 1 day or recur on subsequent days 
(Southall et al., 2007) due to diel and lunar patterns in diving and 
foraging behaviors observed in many cetaceans (Baird et al., 2008; 
Barlow et al., 2020; Henderson et al., 2016; Schorr et al., 2014). It 
is important to note the water depth in the Project Area is shallow 
(ranging up to 10-45 m in the ECRs, and 13 to 41.5 m in the Lease Area) 
and deep diving species, such as sperm whales, are not expected to be 
engaging in deep foraging dives when exposed to noise above NMFS 
harassment thresholds during the specified activities. Therefore, we do 
not anticipate impacts to deep foraging behavior to be impacted by the 
specified activities.
    It is also important to identify that the estimated number of takes 
does not necessarily equate to the number of individual animals US Wind 
expects to harass (which is lower), but rather to the instances of take 
(i.e., exposures above the Level B harassment thresholds) that may 
occur. These instances may represent either seconds to minutes for HRG 
surveys, or, in some cases, longer durations of exposure within a day 
(e.g., pile driving). Some individuals of a species may experience 
recurring instances of take over multiple days throughout the year 
while some members of a species or stock may experience one exposure as 
they move through an area, which means that the number of individuals 
taken is smaller than the total estimated takes. In short, for species 
that are more likely to be migrating through the area and/or for which 
only a comparatively smaller number of takes are predicted (e.g., some 
of the mysticetes), it is more likely that each take represents a 
different individual whereas for non-migrating species with larger 
amounts of predicted take, we expect that the total anticipated takes 
represent exposures of a smaller number of individuals of which some 
would be taken across multiple days.
    For US Wind, impact pile driving of foundation piles is most likely 
to result in a higher magnitude and severity of behavioral disturbance 
than HRG surveys. Impact pile driving has higher source levels and 
longer durations (on an annual basis) than HRG surveys. HRG survey 
equipment also produces much higher frequencies than pile driving, 
resulting in minimal sound propagation. While impact pile driving for 
foundation installation is anticipated to be most impactful for these 
reasons, impacts are minimized through implementation of mitigation 
measures, including use of a sound attenuation system, soft-starts, the 
implementation of clearance zones that would facilitate a delay to pile 
driving commencement, and implementation of shutdown zones. All these 
measures are designed to avoid or minimize harassment. For example, 
given sufficient notice through the use of soft-start, marine mammals 
are expected to move away from a sound source that is disturbing prior 
to becoming exposed to very loud noise levels. The requirement to 
couple visual monitoring and PAM before and during all foundation 
installation will increase the overall capability to detect marine 
mammals compared to one method alone.
    Occasional, milder behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations, and even if 
some smaller subset of the takes is in the form of a longer (several 
hours or a day) and more severe response, if they are not expected to 
be repeated over numerous or sequential days, impacts to individual 
fitness are not anticipated. Also, the effect of disturbance is 
strongly influenced by whether it overlaps with biologically important 
habitats when individuals are present--avoiding biologically important 
habitats will provide opportunities to compensate for reduced or lost 
foraging (Keen et al., 2021). Nearly all studies and experts agree that 
infrequent exposures of a single day or less are unlikely to impact an 
individual's overall energy budget (Farmer et al., 2018; Harris et al., 
2017; King et al., 2015; National Academy of Science, 2017; New et al., 
2014; Southall et al., 2007; Villegas-Amtmann et al., 2015).

[[Page 564]]

Temporary Threshold Shift (TTS)

    TTS is one form of Level B harassment that marine mammals may incur 
through exposure to US Wind's activities and, as described earlier, the 
proposed takes by Level B harassment may represent takes in the form of 
behavioral disturbance, TTS, or both. As discussed in the Potential 
Effects of Specified Activities on Marine Mammals and their Habitat 
section, in general, TTS can last from a few minutes to days, be of 
varying degree, and occur across different frequency bandwidths, all of 
which determine the severity of the impacts on the affected individual, 
which can range from minor to more severe. Impact pile driving is a 
broadband noise sources but generates sounds in the lower frequency 
ranges (with most of the energy below 1-2 kHz, but with a small amount 
energy ranging up to 20 kHz); therefore, in general and all else being 
equal, we would anticipate the potential for TTS is higher in low-
frequency cetaceans (i.e., mysticetes) than other marine mammal hearing 
groups and would be more likely to occur in frequency bands in which 
they communicate. However, we would not expect the TTS to span the 
entire communication or hearing range of any species given that the 
frequencies produced by these activities do not span entire hearing 
ranges for any particular species. Additionally, though the frequency 
range of TTS that marine mammals might sustain would overlap with some 
of the frequency ranges of their vocalizations, the frequency range of 
TTS from US Wind's pile driving activities would not typically span the 
entire frequency range of one vocalization type, much less span all 
types of vocalizations or other critical auditory cues for any given 
species. In addition, the proposed mitigation measures further reduce 
the potential for TTS in mysticetes.
    Generally, both the degree of TTS and the duration of TTS would be 
greater if the marine mammal is exposed to a higher level of energy 
(which would occur when the peak dB level is higher or the duration is 
longer). The threshold for the onset of TTS was discussed previously 
(refer back to Estimated Take). However, source level alone is not a 
predictor of TTS. An animal would have to approach closer to the source 
or remain in the vicinity of the sound source appreciably longer to 
increase the received SEL, which would be difficult considering the 
proposed mitigation and the nominal speed of the receiving animal 
relative to the stationary sources such as impact pile driving. The 
recovery time of TTS is also of importance when considering the 
potential impacts from TTS. In TTS laboratory studies (as discussed in 
Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat), some using exposures of almost an hour in duration or up to 
217 SEL, almost all individuals recovered within 1 day (or less, often 
in minutes) and we note that while the pile driving activities last for 
hours a day, it is unlikely that most marine mammals would stay in the 
close vicinity of the source long enough to incur more severe TTS. 
Overall, given the small number of instances that any individual might 
incur TTS, the low degree of TTS and the short, anticipated duration, 
and the unlikely scenario that any TTS overlapped the entirety of a 
critical hearing range, it is unlikely that TTS (of the nature expected 
to result from the project's activities) would result in behavioral 
changes or other impacts that would impact any individual's (of any 
hearing sensitivity) reproduction or survival.

Permanent Threshold Shift (PTS)

    NMFS proposes to authorize a very small amount of take by PTS to 
some marine mammal individuals. The numbers of proposed annual takes by 
Level A harassment are relatively low for all marine mammal stocks and 
species (table 23). The only activities incidental to which we 
anticipate PTS may occur is from exposure to impact pile driving, which 
produces sounds that are both impulsive and primarily concentrated in 
the lower frequency ranges (below 1 kHz) (David, 2006; Krumpel et al., 
2021).
    There are no PTS data on cetaceans and only one instance of PTS 
being induced in older harbor seals (Reichmuth et al., 2019). However, 
available TTS data (of mid-frequency hearing specialists exposed to 
mid- or high-frequency sounds (Southall et al., 2007; NMFS, 2018; 
Southall et al., 2019)) suggest that most threshold shifts occur in the 
frequency range of the source up to one octave higher than the source. 
We would anticipate a similar result for PTS. Further, no more than a 
small degree of PTS is expected to be associated with any of the 
incurred Level A harassment, given it is unlikely that animals would 
stay in the close vicinity of a source for a duration long enough to 
produce more than a small degree of PTS.
    PTS would consist of minor degradation of hearing capabilities 
occurring predominantly at frequencies one-half to one octave above the 
frequency of the energy produced by pile driving (i.e., the low-
frequency region below 2 kHz) (Cody and Johnstone, 1981; McFadden, 
1986; Finneran, 2015), not severe hearing impairment. If hearing 
impairment occurs from impact pile driving, it is most likely that the 
affected animal would lose a few decibels in its hearing sensitivity, 
which in most cases is not likely to meaningfully affect its ability to 
forage and communicate with conspecifics. In addition, during impact 
pile driving, given sufficient notice through use of soft-start prior 
to implementation of full hammer energy during impact pile driving, 
marine mammals are expected to move away from a sound source that is 
disturbing prior to it resulting in severe PTS.

Auditory Masking or Communication Impairment

    The ultimate potential impacts of masking on an individual are 
similar to those discussed for TTS (e.g., decreased ability to 
communicate, forage effectively, or detect predators), but an important 
difference is that masking only occurs during the time of the signal, 
versus TTS, which continues beyond the duration of the signal. Also, 
though masking can result from the sum of exposure to multiple signals, 
none of which might individually cause TTS. Fundamentally, masking is 
referred to as a chronic effect because one of the key potential 
harmful components of masking is its duration--the fact that an animal 
would have reduced ability to hear or interpret critical cues becomes 
much more likely to cause a problem the longer it is occurring. 
Inherent in the concept of masking is the fact that the potential for 
the effect is only present during the times that the animal and the 
source are in close enough proximity for the effect to occur (and 
further, this time period would need to coincide with a time that the 
animal was utilizing sounds at the masked frequency).
    As our analysis has indicated, for this project we expect that 
impact pile driving foundations have the greatest potential to mask 
marine mammal signals, and this pile driving may occur for several, 
albeit intermittent, hours per day, for multiple days per year. Masking 
is fundamentally more of a concern at lower frequencies (which are pile 
driving dominant frequencies), because low-frequency signals propagate 
significantly further than higher frequencies and because they are more 
likely to overlap both the narrower low-frequency calls of mysticetes, 
as well as many non-communication cues related to fish and invertebrate 
prey, and geologic sounds that inform navigation. However, the area in 
which masking would occur for all marine mammal species and stocks 
(e.g., predominantly

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in the vicinity of the foundation pile being driven) is small relative 
to the extent of habitat used by each species and stock. As mentioned 
above, the Project Area does not overlap critical habitat for any 
species, and temporary avoidance of the pile driving area by marine 
mammals would likely displace animals to areas of sufficient habitat. 
In summary, the nature of US Wind's activities, paired with habitat use 
patterns by marine mammals, does not support the likelihood that the 
level of masking that could occur would have the potential to affect 
reproductive success or survival. Therefore, we are not predicting take 
due to masking effects, and are not proposing to authorize such take.

Impacts on Habitat and Prey

    Construction activities may result in fish and invertebrate 
mortality or injury very close to the source, and all of US Wind's 
activities may cause some fish to leave the area of disturbance. It is 
anticipated that any mortality or injury would be limited to a very 
small subset of available prey and the implementation of mitigation 
measures such as the use of a noise attenuation system during impact 
pile driving would further limit the degree of impact. Behavioral 
changes in prey in response to construction activities could 
temporarily impact marine mammals' foraging opportunities in a limited 
portion of the foraging range but, because of the relatively small area 
of the habitat that may be affected at any given time (e.g., around a 
pile being driven) and the temporary nature of the disturbance on prey 
species, the impacts to marine mammal habitat are not expected to cause 
significant or long-term negative consequences.
    Cable presence is not anticipated to impact marine mammal habitat 
as these would be buried, and any electromagnetic fields emanating from 
the cables are not anticipated to result in consequences that would 
impact marine mammals' prey to the extent they would be unavailable for 
consumption. Although many species of marine mammal prey can detect 
electromagnetic fields, previous studies have shown little impacts on 
habitat use (Hutchinson et al., 2018). Burying the cables and the 
inclusion of protective shielding on cables will also minimize any 
impacts of electromagnetic fields on marine mammal prey.
    The presence of wind turbines within the Lease Area could have 
longer-term impacts on marine mammal habitat, as the project would 
result in the persistence of the structures within marine mammal 
habitat for more than 30 years. The presence of structures such as wind 
turbines is, in general, likely to result in certain oceanographic 
effects in the marine environment, and may alter aggregations and 
distribution of marine mammal zooplankton prey through changing the 
strength of tidal currents and associated fronts, changes in 
stratification, primary production, the degree of mixing, and 
stratification in the water column (Schultze et al., 2020; Chen et al., 
2021; Johnson et al., 2021; Christiansen et al., 2022; Dorrell et al., 
2022).
    As discussed in the Potential Effects of Specified Activities on 
Marine Mammals and their Habitat section, the project would consist of 
no more than 119 foundations (114 WTGs, 4 OSSs, 1 Met tower) in the 
Lease Area, which will gradually become operational following 
construction completion. While there are likely to be oceanographic 
impacts from the presence of operating turbines, meaningful 
oceanographic impacts relative to stratification and mixing that would 
significantly affect marine mammal foraging and prey over large areas 
in key foraging habitats are not anticipated from the US Wind 
activities covered under these proposed regulations, nor is the Project 
area located in the vicinity of any key marine mammal foraging areas. 
For these reasons, if oceanographic features are affected by the 
project during the effective period of the proposed regulations, the 
impact on marine mammal habitat and their prey is likely to be 
comparatively minor.

Mitigation To Reduce Impacts on All Species

    This proposed rulemaking includes a variety of mitigation measures 
designed to minimize impacts on all marine mammals, with a focus on 
North Atlantic right whales (the latter is described in more detail 
below). For impact pile driving of foundation piles, nine overarching 
mitigation measures are proposed, which are intended to reduce both the 
number and intensity of marine mammal takes: (1) seasonal/time of day 
work restrictions; (2) use of multiple PSOs to visually observe for 
marine mammals (with any detection within specifically designated zones 
triggering a delay or shutdown); (3) use of PAM to acoustically detect 
marine mammals, with a focus on detecting baleen whales (with any 
detection within designated zones triggering delay or shutdown); (4) 
implementation of clearance zones; (5) implementation of shutdown 
zones; (6) use of soft-start; (7) use of noise attenuation technology; 
(8) maintaining situational awareness of marine mammal presence through 
the requirement that any marine mammal sighting(s) by US Wind's 
personnel must be reported to PSOs; (9) sound field verification 
monitoring; and (10) Vessel Strike Avoidance measures to reduce the 
risk of a collision with a marine mammal and vessel. For HRG surveys, 
we are requiring six measures: (1) measures specifically for Vessel 
Strike Avoidance; (2) specific requirements during daytime HRG surveys; 
(3) implementation of clearance zones; (4) implementation of shutdown 
zones; (5) use of ramp-up of acoustic sources; and (6) maintaining 
situational awareness of marine mammal presence through the requirement 
that any marine mammal sighting(s) by US Wind's personnel must be 
reported to PSOs.
    NMFS prescribes mitigation measures based on the following 
rationale. For activities with large harassment isopleths, US Wind 
would be required to reduce the noise levels generated to the lowest 
levels practicable and would be required to ensure that they do not 
exceed a noise footprint above that which was modeled, assuming a 10-dB 
attenuation. Use of a soft-start during impact pile driving will allow 
animals to move away from (i.e., avoid) the sound source prior to 
applying higher hammer energy levels needed to install the pile (US 
Wind would not use a hammer energy greater than necessary to install 
piles). Similarly, ramp-up during HRG surveys would allow animals to 
move away and avoid the acoustic sources before they reach their 
maximum energy level. For all activities, clearance zone and shutdown 
zone implementation, which are required when marine mammals are within 
given distances associated with certain impact thresholds for all 
activities, would reduce the magnitude and severity of marine mammal 
take. Additionally, the use of multiple PSOs (WTG, OSS, and Met tower 
foundation installation; HRG surveys), PAM (for impact foundation 
installation), and maintaining awareness of marine mammal sightings 
reported in the region (WTG, OSS, and Met tower foundation 
installation; HRG surveys) would aid in detecting marine mammals that 
would trigger the implementation of the mitigation measures. The 
reporting requirements, including SFV reporting (for foundation 
installation and foundation operation), will assist NMFS in identifying 
if impacts beyond those analyzed in this proposed rule are occurring, 
potentially leading to the need to enact adaptive management

[[Page 566]]

measures in addition to or in the place of the proposed mitigation 
measures.

Mysticetes

    Five mysticete species (comprising five stocks) of cetaceans (North 
Atlantic right whale, humpback whale, fin whale, sei whale, and minke 
whale) may be taken by harassment. These species, to varying extents, 
utilize the specified geographic region, including the Project Area, 
for the purposes of migration, foraging, and socializing. Mysticetes 
are in the low-frequency hearing group.
    Behavioral data on mysticete reactions to pile driving noise are 
scant. Kraus et al. (2019) predicted that the three main impacts of 
offshore wind farms on marine mammals would consist of displacement, 
behavioral disruptions, and stress. Broadly, we can look to studies 
that have focused on other noise sources such as seismic surveys and 
military training exercises, which suggest that exposure to loud 
signals can result in avoidance of the sound source (or displacement if 
the activity continues for a longer duration in a place where 
individuals would otherwise have been staying, which is less likely for 
mysticetes in this area), disruption of foraging activities (if they 
are occurring in the area), local masking around the source, associated 
stress responses, and impacts to prey, as well as TTS or PTS in some 
cases.
    Mysticetes encountered in the Project Area are expected to 
primarily be migrating and, to a lesser degree, may be engaged in 
foraging behavior. The extent to which an animal engages in these 
behaviors in the area is species-specific and varies seasonally. Many 
mysticetes are expected to predominantly be migrating through the 
Project Area towards or from feeding grounds located further north 
(e.g., southern New England region, Gulf of Maine, Canada). While we 
acknowledged above that mortality, hearing impairment, or displacement 
of mysticete prey species may result locally from impact pile driving, 
given the very short duration of and broad availability of prey species 
in the area and the availability of alternative suitable foraging 
habitat for the mysticete species most likely to be affected, any 
impacts on mysticete foraging is expected to be minor. Whales 
temporarily displaced from the Project Area are expected to have 
sufficient remaining feeding habitat available to them and would not be 
prevented from feeding in other areas within the biologically important 
feeding habitats found further north. In addition, any displacement of 
whales or interruption of foraging bouts would be expected to be 
relatively temporary in nature.
    The potential for repeated exposures is dependent upon the 
residency time of whales, with migratory animals unlikely to be exposed 
on repeated occasions and animals remaining in the area to be more 
likely exposed repeatedly. For mysticetes, where relatively low amounts 
of species-specific take by Level B harassment are predicted (compared 
to the abundance of each mysticete species or stock, such as is 
indicated in table 25) and movement patterns suggest that individuals 
would not necessarily linger in a particular area for multiple days, 
each predicted take likely represents an exposure of a different 
individual; the behavioral impacts would, therefore, be expected to 
occur within a single day within a year--an amount that NMFS would not 
expect to impact reproduction or survival. Species with longer 
residence time in the Project Area may be subject to repeated exposures 
across multiple days.
    In general, for this project, the duration of exposures would not 
be continuous throughout any given day, and pile driving would not 
occur on all consecutive days within a given year due to weather delays 
or any number of logistical constraints US Wind has identified. 
Species-specific analysis regarding potential for repeated exposures 
and impacts is provided below.
    Fin, humpback, minke, and sei whales are the only mysticete species 
for which PTS is anticipated and proposed to be authorized. As 
described previously, PTS for mysticetes from some project activities 
may overlap frequencies used for communication, navigation, or 
detecting prey. However, given the nature and duration of the activity, 
the mitigation measures, and likely avoidance behavior, any PTS is 
expected to be of a small degree, would be limited to frequencies where 
pile driving noise is concentrated (i.e., only a small subset of their 
expected hearing range) and would not be expected to impact 
reproductive success or survival.
North Atlantic Right Whale
    North Atlantic right whales are listed as endangered under the ESA 
and as both depleted and strategic stocks under the MMPA. As described 
in the Potential Effects of the Specified Activities on Marine Mammals 
and Their Habitat section, North Atlantic right whales are threatened 
by a low population abundance, higher than average mortality rates, and 
lower than average reproductive rates. Recent studies have reported 
individuals showing high stress levels (e.g., Corkeron et al., 2017) 
and poor health, which has further implications on reproductive success 
and calf survival (Christiansen et al., 2020; Stewart et al., 2021; 
Stewart et al., 2022). As described below, a UME has been designated 
for North Atlantic right whales. Given this, the status of the North 
Atlantic right whale population is of heightened concern and, 
therefore, merits additional analysis and consideration. No injury or 
mortality is anticipated or proposed for authorization for this 
species.
    For North Atlantic right whales, this proposed rule would allow for 
the authorization of up to ten takes, by Level B harassment only, over 
the 5-year period, with a maximum annual allowable take by Level B 
harassment of four (equating to approximately 1.18 percent of the stock 
abundance, if each take were considered to be of a different 
individual). The Project Area is known as a migratory corridor for 
North Atlantic right whales and given the nature of migratory behavior 
(e.g., continuous path), as well as the low number of total takes, we 
anticipate that few, if any, of the instances of take would represent 
repeat takes of any individual, though it could occur if whales are 
engaged in opportunistic foraging behavior. Barco et al. (2015) 
observed North Atlantic right whales engaging in open mouth behavior, 
which is suggestive, though not necessarily indicative, of feeding. 
While opportunistic foraging may occur in the Project area, the area 
does not support prime foraging habitat.
    The highest density of North Atlantic right whales in the Project 
Area occurs in the winter (table 12). The Mid-Atlantic, including the 
Project Area, may be a stopover site for migrating North Atlantic right 
whales moving to or from southeastern calving grounds. North Atlantic 
right whales have been acoustically detected in the vicinity of the 
Project Area year-round (Bailey et al., 2018) with the highest 
occurrences documented during late winter/early spring. Similarly, the 
waters off the coast of Maryland, including those surrounding the 
Project Area in the Maryland Wind Energy Area (MD WEA), have documented 
North Atlantic right whale presence as the area is an important 
migratory route for the species to the northern feeding areas near the 
Gulf of Maine and Georges Banks and to their southern breeding and 
calving grounds off the southeastern U.S. (CETAP, 1982; LaBrecque et 
al., 2015; Salisbury et al., 2016; Davis et al., 2017). However, 
comparatively, the Project Area is not known as an

[[Page 567]]

important area for feeding, breeding, or calving.
    North Atlantic right whales range outside the Project Area for 
their main feeding, breeding, and calving activities (Hayes et al., 
2023). Additional qualitative observations include animals feeding and 
socializing in New England waters, north of the MD WEA (Quintana-Rizzo 
et al., 2021). The North Atlantic right whales observed north of the MD 
WEA were primarily concentrated in the northeastern and southeastern 
sections of the Massachusetts WEA (MA WEA) during the summer (June-
August) and winter (December-February). North Atlantic right whale 
distribution did shift to the west into the Rhode Island/Massachusetts 
(RI/MA WEA) in the spring (March-May). Quintana-Rizzo et al. (2021) 
found that approximately 23 percent of the right whale population is 
present from December through May, and the mean residence time has 
tripled to an average of 13 days during these months. The MD WEA is not 
in or near these areas important to feeding, breeding, and calving 
activities.
    In general, North Atlantic right whales in the Project Area are 
expected to be engaging in migratory behavior. Given the species' 
migratory behavior in the Project Area, we anticipate individual whales 
would be typically migrating through the area during most months when 
foundation installation would occur (given the seasonal restrictions on 
foundation installation, rather than lingering for extended periods of 
time). Other work that involves much smaller harassment zones (e.g., 
HRG surveys) may also occur during periods when North Atlantic right 
whales are using the habitat for migration. It is important to note the 
activities occurring from December through May that may impact North 
Atlantic right whale would be HRG surveys which are planned to take 
place during years 2 and 3 for only 14 days each year from April 
through June and would not result in very high received levels. Across 
all years, if an individual were to be exposed during a subsequent 
year, the impact of that exposure is likely independent of the previous 
exposure given the duration between exposures.
    As described in the Description of Marine Mammals in the Geographic 
Area of Specified Activities, North Atlantic right whales are presently 
experiencing an ongoing UME (beginning in June 2017). Preliminary 
findings support human interactions, specifically vessel strikes and 
entanglements, as the cause of death for the majority of North Atlantic 
right whales. Given the current status of the North Atlantic right 
whale, the loss of even one individual could significantly impact the 
population. No mortality, serious injury, or injury of North Atlantic 
right whales as a result of the project is expected or proposed to be 
authorized. Any disturbance to North Atlantic right whales due to US 
Wind's activities is expected to result in temporary avoidance of the 
immediate area of construction. As no injury, serious injury, or 
mortality is expected or proposed to be authorized, and Level B 
harassment of North Atlantic right whales will be reduced to the level 
of least practicable adverse impact through use of mitigation measures, 
the proposed number of takes of North Atlantic right whales would not 
exacerbate or compound the effects of the ongoing UME.
    As described in the general Mysticetes section above, foundation 
installation is likely to result in the highest amount of annual take 
and is of greatest concern given loud source levels. This activity 
would likely be limited to up to 119 days (114 for WTG monopile 
foundations, 4 days for OSS jacket foundations, and 1 day for Met tower 
pin pile foundations) over a maximum of 3 years, during times when, 
based on the best available scientific data, North Atlantic right 
whales are less frequently encountered due to their migratory behavior. 
The potential types, severity, and magnitude of impacts are also 
anticipated to mirror that described in the general Mysticetes section 
above, including avoidance (the most likely outcome), changes in 
foraging or vocalization behavior, masking, a small amount of TTS, and 
temporary physiological impacts (e.g., change in respiration, change in 
heart rate). Importantly, the effects of the proposed activities are 
expected to be sufficiently low-level and localized to specific areas 
as to not meaningfully impact important behaviors, such as migratory 
behavior of North Atlantic right whales. These takes are expected to 
result in temporary behavioral reactions, such as slight displacement 
(but not abandonment) of migratory habitat or temporary cessation of 
feeding.
    Further, given these exposures are generally expected to occur to 
different individual right whales migrating through (i.e., most 
individuals would not be expected to be impacted on more than 1 day in 
a year), with some subset potentially being exposed on no more than a 
few days within the year, they are unlikely to result in energetic 
consequences that could affect reproduction or survival of any 
individuals.
    Overall, NMFS expects that any behavioral harassment of North 
Atlantic right whales incidental to the specified activities would not 
result in changes to their migration patterns or foraging success, as 
only temporary avoidance of an area during construction is expected to 
occur. As described previously, North Atlantic right whales migrating 
through the Project Area are not expected to remain in this habitat for 
extensive durations, and any temporarily displaced animals would be 
able to return to or continue to travel through and forage in these 
areas once activities have ceased.
    Although acoustic masking may occur in the vicinity of the 
foundation installation activities, based on the acoustic 
characteristics of noise associated with pile driving (e.g., frequency 
spectra, short duration of exposure) and construction surveys (e.g., 
intermittent signals), NMFS expects masking effects to be minimal 
(e.g., impact pile driving) to none (e.g., HRG surveys). In addition, 
masking would likely only occur during the period of time that a North 
Atlantic right whale is in the relatively close vicinity of pile 
driving, which is expected to be intermittent within a day, and 
confined to the months in which North Atlantic right whales are at 
lower densities and primarily moving through the area, anticipated 
mitigation effectiveness, and likely avoidance behaviors. TTS is 
another potential form of Level B harassment that could result in brief 
periods of slightly reduced hearing sensitivity affecting behavioral 
patterns by making it more difficult to hear or interpret acoustic cues 
within the frequency range (and slightly above) of sound produced 
during impact pile driving; however, any TTS would likely be of low 
amount, limited duration, and limited to frequencies where most 
construction noise is centered (below 2 kHz). NMFS expects that right 
whale hearing sensitivity would return to pre-exposure levels shortly 
after migrating through the area or moving away from the sound source.
    As described in the Potential Effects of Specified Activities on 
Marine Mammals and Their Habitat section, the distance of the receiver 
to the source influences the severity of response with greater 
distances typically eliciting less severe responses. NMFS recognizes 
North Atlantic right whales migrating could be pregnant females (in the 
fall) and cows with older calves (in spring) and that these animals may 
slightly alter their migration course in response to any foundation 
pile driving; however, as described in the Potential Effects of 
Specified Activities on Marine

[[Page 568]]

Mammals and Their Habitat section, we anticipate that course diversion 
would be of small magnitude. Hence, while some avoidance of the pile 
driving activities may occur, we anticipate any avoidance behavior of 
migratory North Atlantic right whales would be similar to that of gray 
whales (Tyack et al., 1983), on the order of hundreds of meters up to 1 
to 2 km. This diversion from a migratory path otherwise uninterrupted 
by the proposed activities is not expected to result in meaningful 
energetic costs that would impact annual rates of recruitment of 
survival. NMFS expects that North Atlantic right whales would be able 
to avoid areas during periods of active noise production while not 
being forced out of this portion of their habitat.
    North Atlantic right whale presence in the Project Area is year-
round. However, abundance during summer months is lower compared to the 
winter months with spring and fall serving as ``shoulder seasons'' 
wherein abundance waxes (fall) or wanes (spring). Given this year-round 
habitat usage, in recognition that where and when whales may actually 
occur during project activities is unknown as it depends on the annual 
migratory behaviors, US Wind has proposed, and NMFS is proposing in 
this rule, to require a suite of mitigation measures designed to reduce 
impacts to North Atlantic right whales to the maximum extent 
practicable. These mitigation measures (e.g., seasonal/daily work 
restrictions, vessel separation distances, reduced vessel speed) would 
not only avoid the likelihood of vessel strikes but also would minimize 
the severity of behavioral disruptions by minimizing impacts (e.g., 
through sound reduction using attenuation systems and reduced temporal 
overlap of project activities and North Atlantic right whales). This 
would further ensure that the number of takes by Level B harassment 
that are estimated to occur are not expected to affect reproductive 
success or survivorship by detrimental impacts to energy intake or cow/
calf interactions during migratory transit. However, even in 
consideration of recent habitat-use and distribution shifts, US Wind 
would still be installing foundations when the presence of North 
Atlantic right whales is expected to be lower.
    As described in the Description of Marine Mammals in the Geographic 
Area of Specified Activities section, the Project would be constructed 
within the North Atlantic right whale migratory corridor BIA, which 
represent areas and months within which a substantial portion of a 
species or population is known to migrate. The area over which North 
Atlantic right whales may be harassed is relatively small compared to 
the width of the migratory corridor. The width of the migratory 
corridor in this area is approximately 163.8 km while the width of the 
Lease Area, at the longest point, is approximately 33.1 km. North 
Atlantic right whales may be displaced from their normal path and 
preferred habitat in the immediate activity area (primarily from pile 
driving activities), however, we do not anticipate displacement to be 
of high magnitude (e.g., beyond a few kilometers); thereby, any 
associated bio-energetic expenditure is anticipated to be small. There 
are no known North Atlantic right whale feeding, breeding, or calving 
areas within the Project Area. Prey species are mobile (e.g., calanoid 
copepods can initiate rapid and directed escape responses) and are 
broadly distributed throughout the Project Area (noting again that 
North Atlantic right whale prey is not particularly concentrated in the 
Project Area relative to nearby habitats). Therefore, any impacts to 
prey that may occur are also unlikely to impact marine mammals.
    The most significant measure to minimize impacts to individual 
North Atlantic right whales is the seasonal moratorium on all 
foundation installation activities from December 1 through April 30, 
when North Atlantic right whale abundance in the Project Area is 
expected to be highest. NMFS also expects this measure to greatly 
reduce the potential for mother-calf pairs to be exposed to impact pile 
driving noise above the Level B harassment threshold during their 
annual spring migration through the Project Area from calving grounds 
to primary foraging grounds (e.g., Cape Cod Bay). NMFS expects that 
exposures to North Atlantic right whales would be reduced due to the 
additional proposed mitigation measures that would ensure that any 
exposures above the Level B harassment threshold would result in only 
short-term effects to individuals exposed.
    Pile driving may only begin in the absence of North Atlantic right 
whales (based on visual and passive acoustic monitoring). If pile 
driving has commenced, NMFS anticipates North Atlantic right whales 
would avoid the area, utilizing nearby waters to carry on pre-exposure 
behaviors. However, foundation installation activities must be shut 
down if a North Atlantic right whale is sighted at any distance unless 
a shutdown is not feasible due to risk of injury or loss of life. 
Shutdown may occur anywhere if North Atlantic right whales are seen 
within or beyond the Level B harassment zone, further minimizing the 
duration and intensity of exposure. NMFS anticipates that if North 
Atlantic right whales go undetected and they are exposed to foundation 
installation noise, it is unlikely a North Atlantic right whale would 
approach the sound source locations to the degree that they would 
expose themselves to very high noise levels. This is because typical 
observed whale behavior demonstrates likely avoidance of harassing 
levels of sound where possible (Richardson et al., 1985). These 
measures are designed to avoid PTS and also reduce the severity of 
Level B harassment, including the potential for TTS. While some TTS 
could occur, given the proposed mitigation measures (e.g., delay pile 
driving upon a sighting or acoustic detection and shutting down upon a 
sighting or acoustic detection), the potential for TTS to occur is low.
    The proposed clearance and shutdown measures are most effective 
when detection efficiency is maximized, as the measures are triggered 
by a sighting or acoustic detection. To maximize detection efficiency, 
US Wind proposed, and NMFS is proposing to require, the combination of 
PAM and visual observers. NMFS is proposing to require communication 
protocols with other project vessels, and other heightened awareness 
efforts (e.g., daily monitoring of North Atlantic right whale sighting 
databases) such that as a North Atlantic right whale approaches the 
source (and thereby could be exposed to higher noise energy levels), 
PSO detection efficacy would increase, the whale would be detected, and 
a delay to commencing foundation installation or shutdown (if feasible) 
would occur. In addition, the implementation of a soft-start for impact 
pile driving would provide an opportunity for whales to move away from 
the source if they are undetected, reducing received levels.
    For HRG surveys, the maximum distance to the Level B harassment 
threshold is 200 m. The estimated take, by Level B harassment only, 
associated with HRG surveys is to account for any North Atlantic right 
whale sightings PSOs may miss when HRG acoustic sources are active. 
However, because of the short maximum distance to the Level B 
harassment threshold, the requirement that vessels maintain a distance 
of 500 m from any North Atlantic right whales, the fact that whales are 
unlikely to remain in close proximity to an HRG survey vessel for any 
length of time, and that the acoustic source would be shut down if a 
North Atlantic right whale is observed within 500 m of the source, any 
exposure to

[[Page 569]]

noise levels above the harassment threshold (if any) would be very 
brief. To further minimize exposures, ramp-up of sub-bottom profilers 
must be delayed during the clearance period if PSOs detect a North 
Atlantic right whale (or any other ESA-listed species) within 500 m of 
the acoustic source. With implementation of the proposed mitigation 
requirements, take by Level A harassment is unlikely and, therefore, 
not proposed for authorization. Potential impacts associated with Level 
B harassment would include low-level, temporary behavioral 
modifications, most likely in the form of avoidance behavior. Given the 
high level of precautions taken to minimize both the amount and 
intensity of Level B harassment on North Atlantic right whales, it is 
unlikely that the anticipated low-level exposures would lead to reduced 
reproductive success or survival.
    As described above, no serious injury or mortality, or Level A 
harassment, of North Atlantic right whale is anticipated or proposed 
for authorization. Extensive North Atlantic right whale-specific 
mitigation measures (beyond the robust suite required for all species) 
are expected to further minimize the amount and severity of Level B 
harassment. Given the documented habitat use within the area, the 
majority of the individuals predicted to be taken (including no more 
than ten instances of take, by Level B harassment only, over the course 
of the 5-year rule, with an annual maximum of no more than four) would 
be impacted on only 1, or maybe 2, days in a year as North Atlantic 
right whales utilize this area for migration and would be transiting 
rather than residing in the area for extended periods of time. Further, 
any impacts to North Atlantic right whales are expected to be in the 
form of lower-level behavioral disturbance.
    Given the magnitude and severity of the impacts discussed above, 
and in consideration of the proposed mitigation and other information 
presented, US Wind's activities are not expected to result in impacts 
on the reproduction or survival of any individuals, much less affect 
annual rates of recruitment or survival. For these reasons, we have 
preliminarily determined that the take (by Level B harassment only) 
anticipated and proposed for authorization would have a negligible 
impact on the North Atlantic right whale.
Fin Whale
    The fin whale is listed as Endangered under the ESA, and the 
western North Atlantic stock is considered both Depleted and Strategic 
under the MMPA. No UME has been designated for this species or stock. 
No serious injury or mortality is anticipated or proposed for 
authorization for this species.
    The proposed rule would allow for the authorization of up to 41 
takes, by Level A harassment and Level B harassment, over the 5-year 
period. The maximum annual allowable take by Level A harassment and 
Level B harassment, would be 2 and 18, respectively (combined, this 
annual take (n=20) equates to approximately 0.29 percent of the stock 
abundance if each take were considered to be of a different 
individual). The Project Area does not overlap with any known areas of 
specific biological importance to fin whales. It is possible that some 
subset of the individual whales exposed could be taken several times 
annually.
    Level B harassment is expected to be in the form of behavioral 
disturbance, primarily resulting in avoidance of the Project Area where 
foundation installation is occurring, and some low-level TTS and 
masking that may limit the detection of acoustic cues for relatively 
brief periods of time. Any potential PTS would be minor (limited to a 
few dB) and any TTS would be of short duration and concentrated at one-
half or one octave above the frequency band of pile driving noise (most 
sound is below 2 kHz) which does not include the full predicted hearing 
range of fin whales. If TTS is incurred, hearing sensitivity would 
likely return to pre-exposure levels relatively shortly after exposure 
ends. Any masking or physiological responses would also be of low 
magnitude and severity for reasons described above. Level B harassment 
would be temporary, with primary impacts being temporary displacement 
of the Project Area but not abandonment of any migratory or foraging 
behavior. There is no known foraging habitat for fin whales within the 
Project Area. Any fin whales in the Project Area would be expected to 
be migrating through the area and would have sufficient space to move 
away from Project activities.
    Fin whales are frequently observed in the waters off of Maryland 
and are one of the most commonly detected large baleen whales in 
continental shelf waters, principally from Cape Hatteras in the Mid-
Atlantic northward to Nova Scotia, Canada (CETAP, 1982; Hain et al., 
1992; BOEM 2012; Barco et al., 2015; Edwards et al., 2015; Bailey et 
al., 2018; Hayes et al., 2023). Fin whales have high relative abundance 
in the Mid-Atlantic and Project Area, and most observations occur in 
the winter and early spring months (Williams et al., 2015d; Barco et 
al., 2015), with larger group sizes occurring during the winter months 
(Barco et al., 2015). However, fin whales typically feed in waters off 
of New England and within the Gulf of Maine, areas north of the Project 
Area, as New England and Gulf of St. Lawrence waters represent major 
feeding ground for fin whales (Hayes et al., 2023). Hain et al. (1992) 
based on an analysis of neonate stranding data, suggested that calving 
takes place during October to January in latitudes of the U.S. mid-
Atlantic region; however, it is unknown where calving, mating, and 
wintering occur for most of the population (Hayes et al., 2023).
    Given the documented habitat use within the area, some of the 
individuals taken may be exposed on multiple days. However, as 
described, the project area does not include areas where fin whales are 
known to concentrate for feeding or reproductive behaviors and the 
predicted takes are expected to be in the form of lower-level impacts. 
Given the magnitude and severity of the impacts discussed above 
(including no more than 18 takes, by Level A harassment and Level B 
harassment, over the course of the 5-year rule, and a maximum annual 
allowable take by Level A harassment and Level B harassment, of 2 and 
18 respectively), and in consideration of the proposed mitigation and 
other information presented, US Wind's proposed activities are not 
expected to result in impacts on the reproduction or survival of any 
individuals, much less affect annual rates of recruitment or survival. 
For these reasons, we have preliminarily determined that the take (by 
Level A harassment and Level B harassment) anticipated and proposed to 
be authorized would have a negligible impact on the western North 
Atlantic stock of fin whales.
Humpback Whale
    The West Indies DPS of humpback whales is not listed as threatened 
or endangered under the ESA, but the Gulf of Maine stock, which 
includes individuals from the West Indies DPS, is considered Strategic 
under the MMPA. However, as described in the Description of Marine 
Mammals in the Geographic Area of Specified Activities, humpback whales 
along the Atlantic Coast have been experiencing an active UME as 
elevated humpback whale mortalities have occurred along the Atlantic 
coast from Maine through Florida since January 2016. Of the cases 
examined, approximately 40 percent had evidence of human interaction 
(vessel strike or entanglement). The

[[Page 570]]

UME does not yet provide cause for concern regarding population-level 
impacts and take from vessel strike and entanglement is not proposed to 
be authorized. Despite the UME, the relevant population of humpback 
whales (the West Indies breeding population, or DPS, of which the Gulf 
of Maine stock is a part) remains stable at approximately 12,000 
individuals.
    The proposed rule would allow for the authorization of up to 36 
takes, by Level A harassment and Level B harassment, over the 5-year 
period. The maximum annual allowable take by Level A harassment and 
Level B harassment would be 2 and 16, respectively (combined, this 
maximum annual take (n=18) equates to approximately 1.29 percent of the 
stock abundance if each take were considered to be of a different 
individual). Given that humpback whales are known to forage in areas 
just south of Maryland during the winter and could potentially be 
foraging off Maryland during this time as well, it is likely that some 
subset of the individual whales exposed could be taken several times 
annually.
    Among the activities analyzed, impact pile driving is likely to 
result in the highest amount of Level A harassment annual take of (n=2) 
humpback whales. The maximum amount of annual take proposed to be 
authorized (n=14), by Level B harassment, is highest for impact pile 
driving.
    As described in the Description of Marine Mammals in the Geographic 
Area of Specified Activities section, humpback whales are known to 
occur regularly throughout the Mid-Atlantic Bight, including Maryland 
waters, with strong seasonality of peak occurrences during winter and 
spring (Barco et al., 2015; Bailey et al., 2018; Hayes et al., 2023).
    In the western North Atlantic, humpback whales feed during spring, 
summer, and fall over a geographic range encompassing the eastern coast 
of the United States. Feeding is generally considered to be focused in 
areas north of the Project Area, including a feeding BIA in the Gulf of 
Maine/Stellwagen Bank/Great South Channel, but has been documented 
farther south and off the coast of Virginia. When foraging, humpback 
whales tend to remain in the area for extended durations to capitalize 
on the food sources.
    Assuming humpback whales who are feeding in waters within or 
surrounding the Project Area behave similarly, we expect that the 
predicted instances of disturbance could be comprised of some 
individuals that may be exposed on multiple days if they are utilizing 
the area as foraging habitat. Also similar to other baleen whales, if 
migrating, individuals would likely be exposed to noise levels from the 
project above the harassment thresholds only once during migration 
through the Project Area.
    For all the reasons described in the Mysticetes section above, we 
anticipate any potential PTS and TTS would be concentrated at one-half 
or one octave above the frequency band of pile driving noise (most 
sound is below 2 kHz) which is lower than the full predicted hearing 
range of humpback whales. If TTS is incurred, hearing sensitivity would 
likely return to pre-exposure levels relatively shortly after exposure 
ends. Any masking or physiological responses would also be of low 
magnitude and severity for reasons described above. Limited foraging 
habitat exists for humpback whales within the Project Area as their 
main foraging habitat is located further north. Any humpback whales in 
the Project Area would more likely be migrating through the area.
    Given the magnitude and severity of the impacts discussed above 
(including no more than 36 humpback whale takes over the course of the 
5-year rule, a maximum annual allowable take by Level A harassment and 
Level B harassment, of 2 and 16, respectively), and in consideration of 
the proposed mitigation measures and other information presented, US 
Wind's activities are not expected to result in impacts on the 
reproduction or survival of any individuals, much less affect annual 
rates of recruitment or survival. For these reasons, we have 
preliminarily determined that the take by harassment anticipated and 
proposed to be authorized would have a negligible impact on the Gulf of 
Maine stock of humpback whales.
Minke Whale
    Minke whales are not listed under the ESA, and the Canadian east 
coast stock is neither considered Depleted nor Strategic under the 
MMPA. There are no known areas of specific biological importance in or 
adjacent to the Project Area. As described in the Description of Marine 
Mammals in the Geographic Area of Specified Activities, a UME has been 
designated for this species but is pending closure. No serious injury 
or mortality is anticipated or proposed for authorization for this 
species.
    The proposed rule would allow for the authorization of up to 67 
minke whale takes, by Level A harassment and Level B harassment, over 
the 5-year period. The maximum annual allowable take by Level A 
harassment and Level B harassment, would be 6 and 41, respectively 
(combined, this annual take (n=47) equates to approximately 0.21 
percent of the stock abundance if each take were considered to be of a 
different individual). As described in the Description of Marine 
Mammals in the Geographic Area of Specified Activities section, minke 
whales are common offshore the U.S. eastern seaboard with a strong 
seasonal component in the continental shelf and in deeper, off-shelf 
waters (CETAP, 1982; Hayes et al., 2023). In the Project Area, minke 
whales are predominantly migratory and their known feeding areas are 
north, including a feeding BIA in the southwestern Gulf of Maine and 
George's Bank. Therefore, they would be more likely to be moving 
through (with each take representing a separate individual), though it 
is possible that some subset of the individual whales exposed could be 
taken up to a few times annually.
    As described in the Description of Marine Mammals in the Geographic 
Area of Specified Activities section, there is a UME for minke whales 
along the Atlantic Coast from Maine through South Carolina, with the 
highest number of deaths in Massachusetts, Maine, and New York, and 
preliminary findings in several of the whales have shown evidence of 
human interactions or infectious diseases. However, we note that the 
population abundance is greater than 21,000 and the take proposed for 
authorization through this action is not expected to exacerbate the UME 
in any way.
    We anticipate the impacts of this harassment to follow those 
described in the general Mysticetes section above. Any potential PTS 
would be minor (limited to a few dB) and any TTS would be of short 
duration and concentrated at one-half or one octave above the frequency 
band of pile driving noise (most sound is below 2 kHz) which does not 
include the full predicted hearing range of minke whales. If TTS is 
incurred, hearing sensitivity would likely return to pre-exposure 
levels relatively shortly after exposure ends. Any masking or 
physiological responses would also be of low magnitude and severity for 
reasons described above. Level B harassment would be temporary, with 
primary impacts being temporary displacement of the Project Area but 
not abandonment of any migratory or foraging behavior. Limited foraging 
habitat for minke whales exists in the Project Area as major foraging 
habitats are located further north near New England. Any minke whales 
in the Project Area would be expected to migrate through the area and 
would

[[Page 571]]

have sufficient space to move away from Project activities.
    Given the magnitude and severity of the impacts discussed above 
(including no more than 67 takes over the course of the 5-year rule, 
and a maximum annual allowable take by Level A harassment and Level B 
harassment, of 6 and 41, respectively), and in consideration of the 
proposed mitigation measures and other information presented, US Wind's 
activities are not expected to result in impacts on the reproduction or 
survival of any individuals, much less affect annual rates of 
recruitment or survival. For these reasons, we have preliminarily 
determined that the take by harassment anticipated and proposed to be 
authorized would have a negligible impact on the Canadian eastern 
coastal stock of minke whales.
Sei Whale
    Sei whales are listed as Endangered under the ESA, and the Nova 
Scotia stock is considered both Depleted and Strategic under the MMPA. 
There are no known areas of specific biological importance in or 
adjacent to the Project Area and no UME has been designated for this 
species or stock. No serious injury or mortality is anticipated or 
proposed for authorization for this species.
    The proposed rule would allow for the authorization of up to six 
takes, by Level A harassment and Level B harassment, over the 5-year 
period. The maximum annual allowable take by Level A harassment and 
Level B harassment, would be one and one, respectively (combined, this 
annual take (n=2) equates to approximately 0.03 percent of the stock 
abundance, if each take were considered to be of a different 
individual). As described in the Description of Marine Mammals in the 
Geographic Area of Specified Activities section, most of the sei whale 
distribution is concentrated in Canadian waters and seasonally in 
northerly United States waters, though they are uncommonly observed in 
the waters off of Maryland. Because sei whales are migratory and their 
known feeding areas are east and north of the Project Area (e.g., there 
is a feeding BIA in the Gulf of Maine), they would be more likely to be 
moving through and, considering this and the very low number of total 
takes, it is unlikely that any individual would be exposed more than 
once within a given year.
    With respect to the severity of those individual takes by 
behavioral Level B harassment, we would anticipate impacts to be 
limited to low-level, temporary behavioral responses with avoidance and 
potential masking impacts in the vicinity of the turbine installation 
to be the most likely type of response. Any potential PTS and TTS would 
likely be concentrated at one-half or one octave above the frequency 
band of pile driving noise (most sound is below 2 kHz) which is below 
the full predicted hearing range of sei whales. Moreover, any TTS would 
be of a small degree. Any avoidance of the Project Area due to the 
Project's activities would be expected to be temporary. There is no 
known foraging habitat that exists in the Project Area for sei whales. 
Any sei whales in the Project Area would be expected to be migrating 
through the area.
    Given the magnitude and severity of the impacts discussed above 
(including no more than six takes over the course of the 5-year rule, 
and a maximum annual allowable take by Level A harassment and Level B 
harassment, of one and one, respectively), and in consideration of the 
proposed mitigation measures and other information presented, US Wind's 
activities are not expected to result in impacts on the reproduction or 
survival of any individuals, much less affect annual rates of 
recruitment or survival. For these reasons, we have preliminarily 
determined that the take by harassment anticipated and proposed to be 
authorized would have a negligible impact on the Nova Scotia stock of 
sei whales.

Odontocetes

    In this section, we include information here that applies to all of 
the odontocete species and stocks addressed below. Odontocetes include 
dolphins, porpoises, and all other whales possessing teeth, and we 
further divide them into the following subsections: sperm whales, small 
whales and dolphins, and harbor porpoise. These sub-sections include 
more specific information, as well as conclusions for each stock 
represented.
    All of the takes of odontocetes proposed for authorization 
incidental to US Wind's specified activities are by pile driving and 
HRG surveys. No serious injury or mortality is anticipated or proposed. 
We anticipate that, given ranges of individuals (i.e., that some 
individuals remain within a small area for some period of time), and 
non-migratory nature of some odontocetes in general (especially as 
compared to mysticetes), these takes are more likely to represent 
multiple exposures of a smaller number of individuals than is the case 
for mysticetes, though some takes may also represent one-time exposures 
to an individual. Foundation installation is likely to disturb 
odontocetes to the greatest extent, compared to HRG surveys. While we 
expect animals to avoid the area during foundation installation, their 
habitat range is extensive compared to the area ensonified during these 
activities.
    As described earlier, Level B harassment may include direct 
disruptions in behavioral patterns (e.g., avoidance, changes in 
vocalizations (from masking) or foraging), as well as those associated 
with stress responses or TTS. Odontocetes are highly mobile species 
and, similar to mysticetes, NMFS expects any avoidance behavior to be 
limited to the area near the sound source. While masking could occur 
during foundation installation, it would only occur in the vicinity of 
and during the duration of the activity and would not generally occur 
in a frequency range that overlaps most odontocete communication or any 
echolocation signals. The mitigation measures (e.g., use of sound 
attenuation systems, implementation of clearance and shutdown zones) 
would also minimize received levels such that the severity of any 
behavioral response would be expected to be less than exposure to 
unmitigated noise exposure.
    Any masking or TTS effects are anticipated to be of low severity. 
First, the frequency range of pile driving, the most impactful activity 
proposed to be conducted in terms of response severity, falls within a 
portion of the frequency range of most odontocete vocalizations. 
However, odontocete vocalizations span a much wider range than the low-
frequency construction activities proposed for the project. As 
described above, recent studies suggest odontocetes have a mechanism to 
self-mitigate (i.e., reduce hearing sensitivity) the impacts of noise 
exposure, which could potentially reduce TTS impacts. Any masking or 
TTS is anticipated to be limited and would typically only interfere 
with communication within a portion of an odontocete's range and as 
discussed earlier, the effects would only be expected to be of a short 
duration and, for TTS, a relatively small degree.
    Furthermore, odontocete echolocation occurs predominantly at 
frequencies significantly higher than low-frequency construction 
activities. Therefore, there is little likelihood that threshold shift 
would interfere with feeding behaviors. For HRG surveys, the sources 
operate at higher frequencies than foundation installation activities. 
However, sounds from these sources attenuate very quickly in the water 
column, as described above. Therefore, any potential for PTS and TTS 
and masking is very limited. Further, odontocetes

[[Page 572]]

(e.g., common dolphins, spotted dolphins, bottlenose dolphins) have 
demonstrated an affinity to bow-ride actively surveying HRG surveys. 
Therefore, the severity of any harassment during HRG surveys, if it 
does occur, is anticipated to be very low in severity based on the lack 
of avoidance previously demonstrated by these species.
    The waters off the coast of Maryland are used by several odontocete 
species. None of these species are listed under the ESA, and there are 
no known habitats of particular importance. In general, odontocete 
habitat ranges are far-reaching along the Atlantic coast of the United 
States, and the waters off of Maryland, including the Project Area, do 
not contain any unique odontocete habitat features.
Dolphins and Small Whales (Including Delphinids)
    The 10 species and 11 stocks included in this group for which NMFS 
is proposing to authorize take are not listed under the ESA; however, 
short-finned pilot whales are listed as Strategic under the MMPA. There 
are no known areas of specific biological importance in or around the 
Project Area for any of these species and no UMEs have been designated 
for any of these species. No serious injury, mortality, or take by 
Level A harassment is anticipated or proposed for authorization for 
these species.
    The 10 delphinid species for which NMFS proposes to authorize take 
are: Atlantic spotted dolphin, Pantropical spotted dolphin, common 
bottlenose dolphin (coastal and northern migratory stocks), common 
dolphin, long-finned pilot whale, short-finned pilot whale, killer 
whale, rough-toothed dolphin, striped dolphin, and Risso's dolphin. The 
proposed rule would allow for the authorization of up to between 3 and 
3,013 takes (depending on species), by Level B harassment only, over 
the 5-year period. The maximum annual allowable take for these species 
by Level B harassment, would range from 3 to 1,762, respectively (this 
annual take equates to approximately 0.07 to 24.0 percent of the stock 
abundance, depending on each species, if each take were considered to 
be of a different individual).
    For both stocks of bottlenose dolphins, given the comparatively 
higher number of total annual takes (1,591 for coastal and 1,768 for 
offshore) and the relative number of takes as compared to the stock 
abundance (24.0 and 2.81, respectively), primarily due to the 
progression of the location of impact pile driving each year, while 
some of the takes likely represent exposures of different individuals 
on 1 day a year, it is likely that some subset of the individuals 
exposed could be taken several times annually. For Atlantic spotted 
dolphins, Pantropical spotted dolphins, common dolphins, long- and 
short-finned pilot whales, killer whales, rough-toothed dolphins, 
striped dolphins, and Risso's dolphins, given the number of takes, 
while many of the takes likely represent exposures of different 
individuals on 1 day a year, some subset of the individuals exposed 
could be taken up to a few times annually.
    Dolphins and small delphinids engage in social, reproductive, and 
foraging behavior in the waters offshore of Maryland. However, the 
number of takes, likely movement patterns of the affected species, and 
the intensity of any Level B harassment, combined with the availability 
of alternate nearby habitat that supports the aforementioned behaviors 
suggests that the likely impacts would not impact the reproduction or 
survival of any individuals. While delphinids may be taken on several 
occasions, none of these species are known to have small home ranges 
within the Project Area or known to be particularly sensitive to 
anthropogenic noise. No Level A harassment (PTS) is anticipated or 
proposed to be authorized. Some TTS could occur, but it would be 
limited to the frequency ranges of the activity and any loss of hearing 
sensitivity is anticipated to return to pre-exposure conditions shortly 
after the animals move away from the source or the source ceases.
    Given the magnitude and severity of the impacts discussed above, 
and in consideration of the proposed mitigation and other information 
presented, US Wind's activities are not expected to result in impacts 
on the reproduction or survival of any individuals, much less affect 
annual rates of recruitment or survival. For these reasons, we have 
preliminarily determined that the take by harassment anticipated and 
proposed for authorization would have a negligible impact on all of the 
species and stocks addressed in this section.
Harbor Porpoise
    Harbor porpoises are not listed as Threatened or Endangered under 
the ESA, and the Gulf of Maine/Bay of Fundy stock is neither considered 
Depleted or Strategic under the MMPA. The stock is found predominantly 
in northern U.S. coastal waters (less than 150 m depth) and up into 
Canada's Bay of Fundy (between New Brunswick and Nova Scotia). Although 
the population trend is not known, there are no UMEs or other factors 
that cause particular concern for this stock. No mortality or non-
auditory injury are anticipated or proposed for authorization for this 
stock.
    The proposed rule would allow for the authorization of up to 74 
takes, by Level A harassment and Level B harassment, over the 5-year 
period. The maximum annual allowable take by Level A harassment and 
Level B harassment, would be 3 and 39, respectively (combined, this 
annual take (n=42) equates to approximately 0.04 percent of the stock 
abundance if each take were considered to be of a different 
individual). Given the number of takes, many of the takes likely 
represent exposures of different individuals on 1 day a year.
    Regarding the severity of takes by Level B harassment, because 
harbor porpoises are particularly sensitive to noise, it is likely that 
a fair number of the responses could be of a moderate nature, 
particularly to pile driving. In response to pile driving, harbor 
porpoises are likely to avoid the area during construction, as 
previously demonstrated in Tougaard et al. (2009) in Denmark, in Dahne 
et al. (2013) in Germany, and in Vallejo et al. (2017) in the United 
Kingdom, although a study by Graham et al. (2019) may indicate that the 
avoidance distance could decrease over time. Given that foundation 
installation is scheduled to occur off the coast of Maryland and, given 
alternative foraging areas nearby, any avoidance of the area by 
individuals is not likely to impact the reproduction or survival of any 
individuals.
    With respect to PTS and TTS, the effects on an individual are 
likely relatively low given the frequency bands of pile driving (most 
energy below 2 kHz) compared to harbor porpoise hearing (150 Hz to 160 
kHz peaking around 40 kHz). Specifically, TTS is unlikely to impact 
hearing ability in their more sensitive hearing ranges, or the 
frequencies in which they communicate and echolocate. We expect any PTS 
that may occur to be within the very low end of their hearing range 
where harbor porpoises are not particularly sensitive, and any PTS 
would affect a relatively small portion of the individual's hearing 
range. As such, any PTS would not interfere with key foraging or 
reproductive strategies necessary for reproduction or survival.
    Harbor porpoises are seasonally distributed (Hayes et al., 2023). 
During fall (October through December) and spring (April through June), 
harbor porpoises are widely dispersed from

[[Page 573]]

New Jersey to Maine, with lower densities farther north and south. 
During winter (January to March), intermediate densities of harbor 
porpoises can be found in waters off New Jersey to North Carolina, and 
lower densities are found in waters off New York to New Brunswick, 
Canada. In non-summer months they have been seen from the coastline to 
deep waters (>1,800 m; Westgate et al., 1998), although the majority 
are found over the continental shelf. While harbor porpoises are likely 
to avoid the area during any of the project's construction activities, 
as demonstrated during European wind farm construction, the time of 
year in which work would occur is when harbor porpoises are not in 
highest abundance, and any work that does occur would not result in the 
species' abandonment of the waters off of Maryland.
    Given the magnitude and severity of the impacts discussed above, 
and in consideration of the proposed mitigation and other information 
presented, US Wind's activities are not expected to result in impacts 
on the reproduction or survival of any individuals, much less affect 
annual rates of recruitment or survival. For these reasons, we have 
preliminarily determined that the take by harassment anticipated and 
proposed for authorization would have a negligible impact on the Gulf 
of Maine/Bay of Fundy stock of harbor porpoises.

Phocids (Harbor Seals, Gray Seals, and Harp Seals)

    The harbor seal, gray seal, and harp seal are not listed under the 
ESA, and these stocks are not considered Depleted or Strategic under 
the MMPA. There are no known areas of specific biological importance in 
or around the Project Area. As described in the Description of Marine 
Mammals in the Geographic Area of Specified Activities section, a UME 
has been designated for harbor seals and gray seals and is described 
further below. No serious injury or mortality is anticipated or 
proposed for authorization for any seal species.
    As limited occurrence data for seals are available for the Project 
Area, take estimates for harbor seals, gray seals, and harp seals are 
presented as one estimate. For the three seal species, the proposed 
rule would allow for the total authorization of up to 496 seals by 
Level B harassment, over the 5-year period. The maximum annual 
allowable take for these species, by Level B harassment, would be 341 
seals. If all of the allocated take was attributed to gray seals, this 
take would equate to 1.25 percent of the gray seal stock abundance, if 
each take were considered to be of a different individual. If all of 
the allocated take was attributed to harbor seals, this take would 
equate to 0.56 percent of the harbor seal stock abundance, if each take 
were considered to be of a different individual. If all of the 
allocated take was attributed to harp seals, this take would equate to 
0.004 percent of the harp seal stock abundance. Gray seals, harbor 
seals, and harp seals are considered migratory and none of these 
species have specific feeding areas that have been designated in the 
area, therefore, it is likely that takes of seals would represent 
exposures of different individuals throughout the project duration.
    Harp seals are considered extralimital in the Project Area, 
however, harp seal strandings have been documented in Maryland during 
the winter and spring (Hayes et al., 2023; NAB, 2023a; NAB, 2023b). 
Harbor and gray seals occur in Maryland waters most often from late 
winter to early spring, with harbor seal occurrences being more common 
than gray seals (Hayes et al., 2023). Seals are more likely to be close 
to shore (e.g., closer to the edge of the area ensonified above NMFS' 
harassment threshold), such that exposure to foundation installation 
and HRG surveys would be expected to be at comparatively lower levels. 
Although a gray seal rookery may occur off the coast of Cape Henlopen, 
north of the Project Area, based on the distance of this area from the 
Project Area it is not expected that in-air sounds produced would cause 
the take of hauled out pinnipeds. As this is the closest documented 
pinniped haul-out to the Project Area, NMFS does not expect any 
harassment to occur, nor have we proposed to authorize any take from 
in-air impacts on hauled out seals.
    As described in the Potential Effects of Specified Activities on 
Marine Mammals and Their Habitat section, construction of wind farms in 
Europe resulted in pinnipeds temporarily avoiding construction areas 
but returning within short time frames after construction was complete 
(Carroll et al., 2010; Hamre et al., 2011; Hastie et al., 2015; Russell 
et al., 2016; Brasseur et al., 2010). Effects on pinnipeds that are 
taken by Level B harassment in the Project Area would likely be limited 
to reactions such as increased swimming speeds, increased surfacing 
time, or decreased foraging (if such activity were occurring). Most 
likely, individuals would simply move away from the sound source and be 
temporarily displaced from those areas (Lucke et al., 2006; Edren et 
al., 2010; Skeate et al., 2012; Russell et al., 2016). Given the low 
anticipated magnitude of impacts from any given exposure (e.g., 
temporary avoidance), even potential repeated Level B harassment across 
a few days of some small subset of individuals, which could occur, is 
unlikely to result in impacts on the reproduction or survival of any 
individuals. Moreover, pinnipeds would benefit from the mitigation 
measures described in 50 CFR part 217--Regulations Governing the Taking 
and Importing of Marine Mammals Incidental to Specified Activities.
    As described above, noise from pile driving is mainly low-frequency 
and, while any TTS that does occur would fall within the lower end of 
pinniped hearing ranges (50 Hz to 86 kHz), TTS would not occur at 
frequencies around 5 kHz, where pinniped hearing is most susceptible to 
noise-induced hearing loss (Kastelein et al., 2018). No Level A 
harassment (PTS) is anticipated or proposed to be authorized. In 
summary, any TTS would be of small degree and not occur across the 
entire, or even most sensitive, hearing range. Hence, any impacts from 
TTS are likely to be of low severity and not interfere with behaviors 
critical to reproduction or survival.
    Elevated numbers of harbor seal and gray seal mortalities were 
first observed in July 2018 and occurred across Maine, New Hampshire, 
and Massachusetts until 2020. Based on tests conducted so far, the main 
pathogen found in the seals belonging to that UME was phocine distemper 
virus, although additional testing to identify other factors that may 
be involved in this UME are underway. Currently, the only active UME is 
occurring in Maine with some harbor and gray seals testing positive for 
highly pathogenic avian influenza (HPAI) H5N1. Although elevated 
strandings continue, neither UME (alone or in combination) provides 
cause for concern regarding population-level impacts to any of these 
stocks. For harbor seals, the population abundance is over 61,000 and 
annual mortality/serious injury (M/SI) (n=339) is well below PBR 
(1,729) (Hayes et al., 2023). The population abundance for gray seals 
in the United States is over 27,000, with an estimated overall 
abundance, including seals in Canada, of approximately 450,000. In 
addition, the abundance of gray seals is likely increasing in the U.S. 
Atlantic, as well as in Canada (Hayes et al., 2023).
    Given the magnitude and severity of the impacts discussed above, 
and in consideration of the proposed mitigation and other information 
presented, US Wind's activities are not expected to result in impacts 
on the reproduction or survival of any individuals, much less affect 
annual

[[Page 574]]

rates of recruitment or survival. For these reasons, we have 
preliminarily determined that the take by harassment anticipated and 
proposed for authorization would have a negligible impact on harbor, 
gray, and harp seals.

Preliminary Negligible Impact Determination

    No mortality or serious injury is anticipated to occur or proposed 
to be authorized. As described in the preliminary analysis above, the 
impacts resulting from the project's activities cannot be reasonably 
expected to, and are not reasonably likely to, adversely affect any of 
the species or stocks for which take is proposed for authorization 
through effects on annual rates of recruitment or survival. Based on 
the analysis contained herein of the likely effects of the specified 
activity on marine mammals and their habitat and taking into 
consideration the implementation of the proposed mitigation and 
monitoring measures, NMFS preliminarily finds that the marine mammal 
take from all of US Wind's specified activities combined will have a 
negligible impact on all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals 
estimated to be taken to the most appropriate estimation of abundance 
of the relevant species or stock in our determination of whether an 
authorization is limited to small numbers of marine mammals. When the 
predicted number of individuals to be taken is less than one-third of 
the species or stock abundance, the take is considered to be of small 
numbers. Additionally, other qualitative factors may be considered in 
the analysis, such as the temporal or spatial scale of the activities.
    NMFS proposes to authorize incidental take (by Level A harassment 
and/or Level B harassment) of 19 species of marine mammal (with 20 
managed stocks). The maximum number of instances of takes by combined 
Level A harassment and Level B harassment possible within any one year 
and proposed for authorization relative to the best available 
population abundance is less than one-third for all species and stocks 
potentially impacted.
    For 13 of these species (13 stocks), less than 1 percent of the 
stock abundance is proposed to be authorized for take by Level A and/or 
Level B harassment. For five stocks, less than 5 percent is proposed, 
and for one stock less than 25 percent is proposed (coastal stock of 
bottlenose dolphins), assuming that each instance of take represents a 
different individual. Specific to the North Atlantic right whale, the 
maximum amount of take in any given year, which is by Level B 
harassment only, is four, or 1.18 percent of the stock abundance, 
assuming that each instance of take represents a different individual. 
Please see table 25 for information relating to this small numbers 
analysis.
    Based on the analysis contained herein of the proposed activities 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals would be taken relative to the population 
size of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Classification

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (16 U.S.C. 
1531 et seq.) requires that each Federal agency ensure that any action 
it authorizes, funds, or carries out is not likely to jeopardize the 
continued existence of any endangered or threatened species or result 
in the destruction or adverse modification of designated critical 
habitat. To ensure ESA compliance for the promulgation of rulemakings, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species, in this case with the NOAA GARFO.
    The NMFS Office of Protected Resources is proposing to authorize 
the take of three marine mammal species which are listed under the ESA: 
North Atlantic right, fin, and sei whales. The Permit and Conservation 
Division requested initiation of section 7 consultation on December 5, 
2023, with GARFO for the promulgation of the rulemaking. NMFS will 
conclude the ESA consultation prior to reaching a determination 
regarding the proposed issuance of the authorization. The proposed 
regulations and any subsequent LOA(s) would be conditioned such that, 
in addition to measures included in those documents, US Wind would also 
be required to abide by the reasonable and prudent measures and terms 
and conditions of the Biological Opinion and Incidental Take Statement, 
as issued by NMFS, pursuant to section 7 of the ESA.

Executive Order 12866

    The Office of Management and Budget has determined that this 
proposed rule is not significant for purposes of Executive Order 12866.

Regulatory Flexibility Act (RFA)

    Pursuant to the RFA (5 U.S.C. 601 et seq.), the Chief Counsel for 
Regulation of the Department of Commerce has certified to the Chief 
Counsel for Advocacy of the Small Business Administration that this 
proposed rule, if adopted, would not have a significant economic impact 
on a substantial number of small entities. US Wind is the sole entity 
that would be subject to the requirements in these proposed 
regulations, and US Wind is not a small governmental jurisdiction, 
small organization, or small business, as defined by the RFA. Because 
of this certification, a regulatory flexibility analysis is not 
required and none has been prepared.

Paperwork Reduction Act (PRA)

    Notwithstanding any other provision of law, no person is required 
to respond to, nor shall a person be subject to a penalty for failure 
to comply with, a collection of information subject to the requirements 
of the PRA unless that collection of information displays a currently 
valid Office of Management and Budget (OMB) control number. These 
requirements have been approved by OMB under control number 0648-0151 
and include applications for regulations, subsequent LOA, and reports. 
Send comments regarding any aspect of this data collection, including 
suggestions for reducing the burden, to NMFS.

Coastal Zone Management Act (CZMA)

    The CZMA requires Federal actions within and outside the coastal 
zone that have reasonably foreseeable effects on any coastal use or 
natural resource of the coastal zone be consistent with the enforceable 
policies of a state's federally approved coastal management program (16 
U.S.C. 1456(c)). NMFS has determined that US Wind's application for 
incidental take regulations is not an

[[Page 575]]

activity listed by the MD DNR pursuant to 15 CFR 930.53 and, thus, is 
not subject to Federal consistency requirements in the absence of the 
receipt and prior approval of an unlisted activity review request from 
the State by the Director of NOAA's Office for Coastal Management. 
Consistent with 15 CFR 930.54, NMFS published Notice of Receipt of US 
Wind's application for this incidental take regulation in the Federal 
Register on May 2, 2023 (88 FR 27453) and is now publishing the 
proposed rule. The State of Maryland did not request approval from the 
Director of NOAA's Office for Coastal Management to review US Wind's 
application as an unlisted activity, and the time period for making 
such request has expired. Therefore, NMFS has determined the incidental 
take authorization is not subject to Federal consistency review.

Proposed Promulgation

    As a result of these preliminary determinations, NMFS proposes to 
promulgate an LOA to US Wind authorizing take, by Level A harassment 
and Level B harassment, incidental to construction activities 
associated with the Maryland Offshore Wind Project offshore of Maryland 
for a 5-year period from January 1, 2025, through December 31, 2029, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

Request for Additional Information and Public Comments

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning US Wind's request and the proposed 
regulations (see ADDRESSES). All comments will be reviewed and 
evaluated as we prepare the final rule and make final determinations on 
whether to issue the requested authorization. This proposed rule and 
referenced documents provide all environmental information relating to 
our proposed action for public review.
    Recognizing, as a general matter, that this action is one of many 
current and future wind energy actions, we invite comment on the 
relative merits of the IHA, single-action rule/LOA, and programmatic 
multi-action rule/LOA approaches, including potential marine mammal 
take impacts resulting from this and other related wind energy actions 
and possible benefits resulting from regulatory certainty and 
efficiency.

List of Subjects in 50 CFR Part 217

    Administrative practice and procedure, Endangered and threatened 
species, Fish, Fisheries, Marine mammals, Penalties, Reporting and 
recordkeeping requirements, Wildlife.

    Dated: December 6, 2023.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, NMFS proposes to amend 50 
CFR part 217 to read as follows:

PART 217--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS INCIDENTAL TO SPECIFIED ACTIVITIES

0
1. The authority citation for part 217 continues to read as follows:

    Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.

0
2. Add subpart II, consisting of Sec. Sec.  217.340 through 217.349, to 
read as follows:
Subpart II--Taking Marine Mammals Incidental to the Maryland Offshore 
Wind Project Offshore of Maryland
Sec.
217.340 Specified activity and specified geographical region.
217.341 Effective dates.
217.342 Permissible methods of taking.
217.343 Prohibitions.
217.344 Mitigation requirements.
217.345 Monitoring and reporting requirements.
217.346 Letter of Authorization.
217.347 Modifications of Letter of Authorization.
217.348-217.349 [Reserved]

Subpart II--Taking Marine Mammals Incidental to the Maryland 
Offshore Wind Project Offshore of Maryland


Sec.  217.340  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply to activities associated with 
the Maryland Offshore Wind Project (hereafter referred to as the 
``Project'') by US Wind, Inc. (hereafter referred to as ``LOA 
Holder''), and those persons it authorizes or funds to conduct 
activities on its behalf in the area outlined in paragraph (b) of this 
section. Requirements imposed on LOA Holder must be implemented by 
those persons it authorizes or funds to conduct activities on its 
behalf.
    (b) The specified geographical region is the Mid-Atlantic Bight, 
which includes, but is not limited to, the Bureau of Ocean Energy 
Management (BOEM) Lease Area Outer Continental Shelf (OCS)-A 0490 
Commercial Lease of Submerged Lands for Renewable Energy Development, 
along the relevant Export Cable Corridors (ECCs), and at the sea-to-
shore transition points located within Delaware Seashore State Park.
    (c) The specified activities are impact pile driving of wind 
turbine generator (WTG), offshore substation (OSS), and a 
meteorological tower (Met tower) foundations; high-resolution 
geophysical (HRG) site characterization surveys; vessel transit within 
the specified geographical region to transport crew, supplies, and 
materials; WTG and OSS operation; fishery and ecological monitoring 
surveys; placement of scour protection; and trenching, laying, and 
cable burial activities.


Sec.  217.341  Effective dates.

    The regulations in this subpart are effective from January 1, 2025, 
through December 31, 2029.


Sec.  217.342  Permissible methods of taking.

    Under the LOA, issued pursuant to Sec. Sec.  216.106 of this 
chapter and 217.346, the LOA Holder, and those persons it authorizes or 
funds to conduct activities on its behalf, may incidentally, but not 
intentionally, take marine mammals within the vicinity of BOEM Lease 
Area OCS-A 0490 Commercial Lease of Submerged Lands for Renewable 
Energy Development, provided the LOA Holder is in complete compliance 
with all terms, conditions, and requirements of the regulations in this 
subpart and the appropriate LOA:
    (a) By Level B harassment associated with the acoustic disturbance 
of marine mammals by impact pile driving (WTG, OSS, and Met tower 
foundation installation) and HRG site characterization surveys;
    (b) By Level A harassment associated with the acoustic disturbance 
of marine mammals by impact pile driving of WTG foundations;
    (c) Take by mortality or serious injury of any marine mammal 
species is not authorized; and
    (d) The incidental take of marine mammals by the activities listed 
in paragraphs (a) and (b) of this section is limited to the following 
species:

[[Page 576]]



                        Table 1 to Paragraph (d)
------------------------------------------------------------------------
    Marine mammal species        Scientific name            Stock
------------------------------------------------------------------------
North Atlantic right whale..  Eubalaena glacialis.  Western Atlantic.
Fin whale...................  Balaenoptera          Western North
                               physalus.             Atlantic.
Humpback whale..............  Megaptera             Gulf of Maine.
                               novaeangliae.
Minke whale.................  Balaenoptera          Canadian Eastern
                               acutorostrata.        Coastal.
Sei whale...................  Balaenoptera          Nova Scotia.
                               borealis.
Killer whale................  Orcinus orca........  Western North
                                                     Atlantic.
Atlantic spotted dolphin....  Stenella frontalis..  Western North
                                                     Atlantic.
Pantropical spotted dolphin.  Stenella attenuata..  Western North
                                                     Atlantic.
Bottlenose dolphin..........  Tursiops truncatus..  Western North
                                                     Atlantic--Offshore.
                                                    Northern Migratory
                                                     Coastal.
Common dolphin..............  Delphinus delphis...  Western North
                                                     Atlantic.
Long-finned pilot whale.....  Globicephala melas..  Western North
                                                     Atlantic.
Short-finned pilot whale....  Globicephala          Western North
                               macrorhynchus.        Atlantic.
Risso's dolphin.............  Grampus griseus.....  Western North
                                                     Atlantic.
Rough-toothed dolphin.......  Steno bredanensis...  Western North
                                                     Atlantic.
Striped dolphin.............  Stenella              Western North
                               coeruleoalba.         Atlantic.
Harbor porpoise.............  Phocoena phocoena...  Gulf of Maine/Bay of
                                                     Fundy.
Gray seal...................  Halichoerus grypus..  Western North
                                                     Atlantic.
Harbor seal.................  Phoca vitulina......  Western North
                                                     Atlantic.
Harp seal...................  Pagophilus            Western North
                               groenlandicus.        Atlantic.
------------------------------------------------------------------------

Sec.  217.343  Prohibitions.

    Except for the takings described in Sec.  217.342 and authorized by 
the LOA issued under this subpart, it is unlawful for any person to do 
any of the following in connection with the activities described in 
this subpart:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or the LOA issued under this subpart;
    (b) Take any marine mammal not specified in Sec.  217.342(d);
    (c) Take any marine mammal specified in the LOA in any manner other 
than as specified in the LOA; or
    (d) Take any marine mammal specified in Sec.  217.342(d), after 
NMFS Office of Protected Resources determines such taking results in 
more than a negligible impact on the species or stocks of such marine 
mammals.


Sec.  217.344  Mitigation requirements.

    When conducting the activities identified in Sec.  217.340(c) 
within the area described in Sec.  217.340(b), LOA Holder must 
implement the mitigation measures contained in this section and any LOA 
issued under Sec. Sec.  217.346 and 217.347. These mitigation measures 
include, but are not limited to:
    (a) General conditions. LOA Holder must comply with the following 
general measures:
    (1) A copy of any issued LOA must be in the possession of LOA 
Holder and its designees, all vessel operators, visual protected 
species observers (PSOs), passive acoustic monitoring (PAM) operators, 
pile driver operators, and any other relevant designees operating under 
the authority of the issued LOA;
    (2) LOA Holder must conduct training for construction, survey, and 
vessel personnel and the marine mammal monitoring team (PSO and PAM 
operators) prior to the start of all in-water construction activities 
in order to explain responsibilities, communication procedures, marine 
mammal detection and identification, mitigation, monitoring, and 
reporting requirements, safety and operational procedures, and 
authorities of the marine mammal monitoring team(s). This training must 
be repeated for new personnel who join the work during the project. A 
description of the training program must be provided to NMFS at least 
60 days prior to the initial training before in-water activities begin. 
Confirmation of all required training must be documented on a training 
course log sheet and reported to NMFS Office of Protected Resources 
prior to initiating project activities;
    (3) Prior to and when conducting any in-water activities and vessel 
operations, LOA Holder personnel and contractors (e.g., vessel 
operators, PSOs) must use available sources of information on North 
Atlantic right whale presence in or near the Project Area including 
daily monitoring of the Right Whale Sightings Advisory System, and 
monitoring of U.S. Coast Guard VHF Channel 16 throughout the day to 
receive notification of any sightings and/or information associated 
with any Slow Zones (i.e., Dynamic Management Areas (DMAs) and/or 
acoustically-triggered slow zones) to provide situational awareness for 
both vessel operators, PSO(s), and PAM operator(s); The marine mammal 
monitoring team must monitor these systems no less than every 4 hours;
    (4) Any marine mammal observed by project personnel must be 
immediately communicated to any on-duty PSOs, PAM operator(s), and all 
vessel captains. Any large whale observation or acoustic detection by 
PSOs or PAM operators must be conveyed to all vessel captains;
    (5) For North Atlantic right whales, any visual detection or 
acoustic detection within the PAM monitoring zone must trigger a delay 
to the commencement of pile driving. Any visual detection within 500 m 
must trigger a delay to the commencement of HRG surveys;
    (6) In the event that a large whale is sighted or acoustically 
detected that cannot be confirmed as a non-North Atlantic right whale, 
it must be treated as if it were a North Atlantic right whale for 
purposes of mitigation;
    (7) If a delay to commencing an activity is called for by the Lead 
PSO or PAM operator, LOA Holder must take the required mitigative 
action. If a delay or shutdown of an activity is called for by the Lead 
PSO or PAM operator, LOA Holder must take the required mitigative 
action unless shutdown would result in imminent risk of injury or loss 
of life to an individual, pile refusal, or pile instability. Any 
disagreements between the Lead PSO, PAM operator, and the activity 
operator regarding delays or shutdowns would only be discussed after 
the mitigative action has occurred;
    (8) If an individual from a species for which authorization has not 
been granted, or a species for which authorization has been granted but 
the authorized take number has been met, is observed entering or within 
the relevant Level B harassment zone prior to

[[Page 577]]

beginning a specified activity, the activity must be delayed. If the 
activity is ongoing, it must be shut down immediately, unless shutdown 
would result in imminent risk of injury or loss of life to an 
individual, pile refusal, or pile instability. The activity must not 
commence or resume until the animal(s) has been confirmed to have left 
and is on a path away from the Level B harassment zone or after 15 
minutes for small odontocetes and pinnipeds, and 30 minutes for all 
other species with no further sightings;
    (9) For in-water construction heavy machinery activities listed in 
Sec.  217.340(c), if a marine mammal is on a path towards or comes 
within 10 meters (m) (32.8 feet (ft)) of equipment, LOA Holder must 
cease operations until the marine mammal has moved more than 10 m on a 
path away from the activity to avoid direct interaction with equipment;
    (10) All vessels must be equipped with a properly installed, 
operational Automatic Identification System (AIS) device and LOA Holder 
must report all Maritime Mobile Service Identity (MMSI) numbers to NMFS 
Office of Protected Resources;
    (11) By accepting the issued LOA, LOA Holder consents to on-site 
observation and inspections by Federal agency personnel (including NOAA 
personnel) during activities described in this subpart, for the 
purposes of evaluating the implementation and effectiveness of measures 
contained within the LOA and this subpart;
    (12) It is prohibited to assault, harm, harass (including sexually 
harass), oppose, impede, intimidate, impair, or in any way influence or 
interfere with a PSO, PAM Operator, or vessel crew member acting as an 
observer, or attempt the same. This prohibition includes, but is not 
limited to, any action that interferes with an observer's 
responsibilities, or that creates an intimidating, hostile, or 
offensive environment. Personnel may report any violations to the NMFS 
Office of Law Enforcement; and
    (13) The LOA Holder must also abide by the reasonable and prudent 
measures and terms and conditions of the Biological Opinion and 
Incidental Take Statement, as issued by NMFS, pursuant to section 7 of 
the Endangered Species Act.
    (b) Vessel strike avoidance measures. LOA Holder must comply with 
the following vessel strike avoidance measures, unless a situation 
presents a threat to the health, safety, or life of a person or when a 
vessel, actively engaged in emergency rescue or response duties, 
including vessel-in-distress or environmental crisis response, requires 
speeds in excess of 10 kn to fulfill those responsibilities, while in 
the specified geographical region:
    (1) Prior to the start of the Project's activities involving 
vessels, all vessel personnel must receive a protected species training 
that covers, at a minimum, identification of marine mammals that have 
the potential to occur where vessels would be operating; detection 
observation methods in both good weather conditions (i.e., clear 
visibility, low winds, low sea states) and bad weather conditions 
(i.e., fog, high winds, high sea states, with glare); sighting 
communication protocols; all vessel speed and approach limit mitigation 
requirements (e.g., vessel strike avoidance measures); and information 
and resources available to the project personnel regarding the 
applicability of Federal laws and regulations for protected species. 
This training must be repeated for any new vessel personnel who join 
the Project. Confirmation of the observers' training and understanding 
of the Incidental Take Authorization (ITA) requirements must be 
documented on a training course log sheet and reported to NMFS;
    (2) LOA Holder, regardless of their vessel's size, must maintain a 
vigilant watch for all marine mammals and slow down, stop their vessel, 
or alter course to avoid striking any marine mammal;
    (3) LOA Holder's underway vessels (e.g., transiting, surveying) 
operating at any speed must have a dedicated visual observer on duty at 
all times to monitor for marine mammals within a 180[deg] direction of 
the forward path of the vessel (90[deg] port to 90[deg] starboard) 
located at an appropriate vantage point for ensuring vessels are 
maintaining appropriate separation distances. Visual observers must be 
equipped with alternative monitoring technology (e.g., night vision 
devices, infrared cameras) for periods of low visibility (e.g., 
darkness, rain, fog, etc.). The dedicated visual observer must receive 
prior training on protected species detection and identification, 
vessel strike minimization procedures, how and when to communicate with 
the vessel captain, and reporting requirements in this subpart. Visual 
observers may be third-party observers (i.e., NMFS-approved PSOs) or 
trained crew members, as defined in paragraph (b)(1) of this section;
    (4) LOA Holder must continuously monitor the U.S. Coast Guard VHF 
Channel 16 at the onset of transiting through the duration of 
transiting, over which North Atlantic right whale sightings are 
broadcasted. At the onset of transiting and at least once every 4 
hours, vessel operators and/or trained crew member(s) must also monitor 
the project's Situational Awareness System, WhaleAlert, and relevant 
NOAA information systems such as the Right Whale Sighting Advisory 
System (RWSAS) for the presence of North Atlantic right whales;
    (5) All LOA Holder's vessels must transit at 10 kn or less within 
any active North Atlantic right whale Slow Zone (i.e., Dynamic 
Management Areas (DMAs) or acoustically-triggered slow zone);
    (6) LOA Holder's vessels, regardless of size, must immediately 
reduce speed to 10 kn or less for at least 24 hours when a North 
Atlantic right whale is sighted at any distance by any project-related 
personnel or acoustically detected by any project-related PAM system. 
Each subsequent observation or acoustic detection in the Project area 
shall trigger an additional 24-hour period. If a North Atlantic right 
whale is reported via any of the monitoring systems (refer back to 
(b)(4) of this section) within 10 kilometers (km; 6.2 miles (mi)) of a 
transiting vessel(s), that vessel must operate at 10 knots (kn; 11.5 
miles per hour (mph)) or less for 24 hours following the reported 
detection;
    (7) LOA Holder's vessels, regardless of size, must immediately 
reduce speed to 10 kn or less when any large whale (other than a North 
Atlantic right whale) is observed within 500 m (1,640 ft) of an 
underway vessel;
    (8) If LOA Holder's vessel(s) are traveling at speeds greater than 
10 kn (i.e., no speed restrictions are enacted) in a transit corridor 
from a port to the Lease Area, in addition to the required dedicated 
visual observer, LOA Holder must monitor the transit corridor in real-
time with PAM prior to and during transits. If a North Atlantic right 
whale is detected via visual observation or PAM within or approaching 
the transit corridor, all crew transfer vessels must travel at 10 kn or 
less for 24 hours following the detection. Each subsequent detection 
shall trigger a 24-hour reset. A slowdown in the transit corridor 
expires when there has been no further visual or acoustic detection in 
the transit corridor in the past 24 hours;
    (9) LOA Holder's vessels must maintain a minimum separation 
distance of 500 m from North Atlantic right whales. If underway, all 
vessels must steer a course away from any sighted North Atlantic right 
whale at 10 kn or less such that the 500-m minimum separation distance 
requirement is not violated. If a North Atlantic right whale is sighted 
within 500 m of an underway vessel, that vessel must reduce speed

[[Page 578]]

and shift the engine to neutral. Engines must not be engaged until the 
whale has moved outside of the vessel's path and beyond 500 m. If a 
whale is observed but cannot be confirmed as a species other than a 
North Atlantic right whale, the vessel operator must assume that it is 
a North Atlantic right whale and take the vessel strike avoidance 
measures described in this paragraph (b)(9);
    (10) LOA Holder's vessels must maintain a minimum separation 
distance of 100 m (328 ft) from sperm whales and non-North Atlantic 
right whale baleen whales. If one of these species is sighted within 
100 m of a transiting vessel, LOA Holder's vessel must reduce speed and 
shift the engine to neutral. Engines must not be engaged until the 
whale has moved outside of the vessel's path and beyond 100 m;
    (11) LOA Holder's vessels must maintain a minimum separation 
distance of 50 m (164 ft) from all delphinoid cetaceans and pinnipeds 
with an exception made for those that approach the vessel (i.e., bow-
riding dolphins). If a delphinid cetacean or pinniped is sighted within 
50 m of a transiting vessel, LOA Holder's vessel must shift the engine 
to neutral, with an exception made for those that approach the vessel 
(e.g., bow-riding dolphins). Engines must not be engaged until the 
animal(s) has moved outside of the vessel's path and beyond 50 m;
    (12) When a marine mammal(s) is sighted while LOA Holder's 
vessel(s) is transiting, the vessel must take action as necessary to 
avoid violating the relevant separation distances (e.g., attempt to 
remain parallel to the animal's course, slow down, and avoid abrupt 
changes in direction until the animal has left the area). This measure 
does not apply to any vessel towing gear or any situation where 
respecting the relevant separation distance would be unsafe (i.e., any 
situation where the vessel is navigationally constrained);
    (13) LOA Holder's vessels underway must not divert or alter course 
to approach any marine mammal;
    (14) LOA Holder is required to abide by other speed and approach 
regulations. Nothing in this subpart exempts vessels from any other 
applicable marine mammal speed and approach regulations;
    (15) LOA Holder must check, daily, for information regarding the 
establishment of mandatory or voluntary vessel strike avoidance areas 
(i.e., DMAs, SMAs, Slow Zones) and any information regarding North 
Atlantic right whale sighting locations;
    (16) LOA Holder must submit a North Atlantic Right Whale Vessel 
Strike Avoidance Plan to NMFS Office of Protected Resources for review 
and approval at least 180 days prior to the planned start of vessel 
activity. The plan must provide details on the vessel-based observer 
and PAM protocols for transiting vessels. If a plan is not submitted or 
approved by NMFS prior to vessel operations, all project vessels 
transiting, year-round, must travel at speeds of 10 kn or less. LOA 
Holder must comply with any approved North Atlantic Right Whale Vessel 
Strike Avoidance Plan; and
    (17) Speed over ground will be used to measure all vessel speed 
restrictions.
    (c) WTG, OSS, Met tower foundation installation. The following 
requirements apply to impact pile driving activities associated with 
the installation of WTG, OSS, and Met tower foundations:
    (1) Impact pile driving must not occur December 1 through April 30.
    (2) Monopiles must be no larger than 11 m in diameter. Hammer 
energies must not exceed 4,400 kilojoules (kJ) for monopile 
installation. No more than one monopile may be installed per day, 
unless otherwise approved by NMFS. Pin piles for the OSSs must be no 
larger than 3 m in diameter. Hammer energies must not exceed 1,500 kJ 
for 3-m pin pile installation. No more than four 3-m pin piles may be 
installed per day. Met tower pin piles must be no larger than 1.8 m in 
diameter, and hammer energies must not exceed 500 kJ for Met tower pin 
pile installation. No more than two 1.8-m pin piles may be installed 
per day.
    (3) LOA Holder must not initiate pile driving earlier than 1 hour 
prior to civil sunrise or later than 1.5 hours prior to civil sunset, 
unless the LOA Holder submits, and NMFS approves, an Alternative 
Monitoring Plan as part of the Pile Driving and Marine Mammal 
Monitoring Plan that reliably demonstrates the efficacy of their night 
vision devices.
    (4) Soft-start must occur at the beginning of impact driving and at 
any time following a cessation of impact pile driving of 30 minutes or 
longer. Soft-start would involve initiating hammer operation at a 
reduced energy level (relative to full operating capacity) followed by 
a waiting period. For impact pile driving of monopiles and pin piles, 
the LOA Holder must utilize a soft-start protocol by performing four to 
six strikes per minute at 10 to 20 percent of the maximum hammer 
energy, for a minimum of 20 minutes.
    (5) LOA Holder must establish clearance and shutdown zones, which 
must be measured using the radial distance around the pile being 
driven. If a marine mammal is detected within or about to enter the 
applicable clearance zones, prior to the beginning of soft-start 
procedures, impact pile driving must be delayed until the animal has 
been visually observed exiting the clearance zone or until a specific 
time period has elapsed with no further sightings. The specific time 
periods are 15 minutes for small odontocetes and pinnipeds, and 30 
minutes for all other species.
    (6) For North Atlantic right whales, any visual observation or 
acoustic detection within the PAM monitoring zone must trigger a delay 
to the commencement of pile driving. The clearance zone may only be 
declared clear if no North Atlantic right whale acoustic or visual 
detections have occurred within the clearance zone during the 60-minute 
monitoring period.
    (7) LOA Holder must deploy at least two functional noise abatement 
systems that reduce noise levels to the modeled harassment isopleths, 
assuming 10-dB attenuation, during all impact pile driving and comply 
with the following measures:
    (i) A single bubble curtain must not be used;
    (ii) Any bubble curtain(s) must distribute air bubbles using an air 
flow rate of at least 0.5 m\3\/(minute*m). The bubble curtain(s) must 
surround 100 percent of the piling perimeter throughout the full depth 
of the water column. In the unforeseen event of a single compressor 
malfunction, the offshore personnel operating the bubble curtain(s) 
must adjust the air supply and operating pressure such that the maximum 
possible sound attenuation performance of the bubble curtain(s) is 
achieved;
    (iii) The lowest bubble ring must be in contact with the seafloor 
for the full circumference of the ring, and the weights attached to the 
bottom ring must ensure 100-percent seafloor contact;
    (iv) No parts of the ring or other objects may prevent full 
seafloor contact with a bubble curtain ring;
    (v) Construction contractors must train personnel in the proper 
balancing of airflow to the bubble curtain ring. LOA Holder must 
provide NMFS Office of Protected Resources with a bubble curtain 
performance test and maintenance report to review within 72 hours after 
each pile using a bubble curtain is installed. Additionally, a full 
maintenance check (e.g., manually clearing holes) must occur prior to 
each pile being installed; and
    (vi) Corrections to the bubble ring(s) to meet the performance 
standards in this paragraph (c)(8) must occur prior to impact pile 
driving of monopiles, 3-m pin piles, and 1.8-m pin piles. If LOA

[[Page 579]]

Holder uses a noise mitigation device in addition to the bubble 
curtain, LOA Holder must maintain similar quality control measures as 
described in this paragraph (c)(7).
    (8) LOA Holder must utilize NMFS-approved PAM systems, as described 
in paragraph(c)(16) of this section. The PAM system components (i.e., 
acoustic buoys) must not be placed closer than 1 km to the pile being 
driven so that the activities do not mask the PAM system. LOA Holder 
must provide a demonstration of and justification for the detection 
range of the system they plan to deploy while considering potential 
masking from concurrent pile driving and vessel noise. The PAM system 
must be able to detect a vocalization of North Atlantic right whales up 
to 10 km (6.2 mi).
    (9) LOA Holder must utilize PSO(s) and PAM operator(s), as 
described in Sec.  217.345(c), to monitor the clearance and shutdown 
zones. At least three on-duty PSOs must be on the pile driving platform 
and any additional platforms used.
    (10) If a marine mammal is detected (visually or acoustically) 
entering or within the respective shutdown zone after pile driving has 
begun, the PSO or PAM operator must call for a shutdown of pile driving 
and LOA Holder must stop pile driving immediately, unless shutdown is 
not practicable due to imminent risk of injury or loss of life to an 
individual or risk of damage to a vessel that creates risk of injury or 
loss of life for individuals, or the lead engineer determines there is 
pile refusal or pile instability. If pile driving is not shut down in 
one of these situations, LOA Holder must reduce hammer energy to the 
lowest level practicable and the reason(s) for not shutting down must 
be documented and reported to NMFS Office of Protected Resources within 
the applicable monitoring reports (e.g., weekly, monthly).
    (11) A visual observation by PSOs at any distance or acoustic 
detection within the PAM monitoring zone of a North Atlantic right 
whale triggers shutdown requirements as per paragraph 10 of this 
section. If pile driving has been shut down due to the presence of a 
North Atlantic right whale, pile driving may not restart until the 
North Atlantic right whale has neither been visually or acoustically 
detected for 30 minutes.
    (12) If pile driving has been shut down due to the presence of a 
marine mammal other than a North Atlantic right whale, pile driving 
must not restart until either the marine mammal(s) has voluntarily left 
the specific clearance zones and has been visually or acoustically 
confirmed beyond that clearance zone, or, when specific time periods 
have elapsed with no further sightings or acoustic detections have 
occurred. The specific time periods are 15 minutes for small 
odontocetes and pinnipeds and 30 minutes for all other marine mammal 
species. In cases where these criteria are not met, pile driving may 
restart only if necessary to maintain pile stability at which time LOA 
Holder must use the lowest hammer energy practicable to maintain 
stability.
    (13) Pile driving sound levels must not exceed modeled distances to 
NMFS marine mammal Level A harassment and Level B harassment thresholds 
assuming 10-dB attenuation.
    (14) LOA Holder must conduct sound field verification (SFV) 
measurements during pile driving activities associated with the 
installation of, at minimum, the first three monopile foundations and 
the first three full jacket foundations (inclusive of all pin piles for 
a specific jacket foundation) for each of the three construction 
campaigns. SFV measurements must continue until at least three 
consecutive monopiles and three entire jacket foundations demonstrate 
noise levels are at or below those modeled, assuming 10-decibels (dB) 
of attenuation. Subsequent SFV measurements are also required should 
larger piles be installed or if additional piles are driven that may 
produce louder sound fields than those previously measured (e.g., 
higher hammer energy, greater number of strikes, etc.). SFV 
measurements must be conducted as follows:
    (i) Measurements must be made at a minimum of four distances from 
the pile(s) being driven, along a single transect, in the direction of 
lowest transmission loss (i.e., projected lowest transmission loss 
coefficient), including, but not limited to, 750 m (2,460 ft) and three 
additional ranges selected such that measurement of Level A harassment 
and Level B harassment isopleths are accurate, feasible, and avoids 
extrapolation. At least one additional measurement at an azimuth 90 
degrees from the array at 750 m must be made. At each location, there 
must be a near bottom and mid-water column hydrophone (measurement 
systems);
    (ii) The recordings must be continuous throughout the duration of 
all pile driving of each foundation;
    (iii) The SFV measurement systems must have a sensitivity 
appropriate for the expected sound levels from pile driving received at 
the nominal ranges throughout the installation of the pile. The 
frequency range of SFV measurement systems must cover the range of at 
least 20 hertz (Hz) to 20 kilohertz (kHz). The SFV measurement systems 
must be designed to have omnidirectional sensitivity so that the 
broadband received level of all pile driving exceeds the system noise 
floor by at least 10 dB. The dynamic range of the SFV measurement 
system must be sufficient such that at each location, the signals 
prevent poor signal-to-noise ratios for low amplitude signals and avoid 
clipping, nonlinearity, and saturation for high amplitude signals;
    (iv) All hydrophones used in SFV measurements systems are required 
to have undergone a full system, traceable laboratory calibration 
conforming to International Electrotechnical Commission (IEC) 60565, or 
an equivalent standard procedure, from a factory or accredited source 
to ensure the hydrophone receives accurate sound levels, at a date not 
to exceed 2 years before deployment. Additional in-situ calibration 
checks using a pistonphone are required to be performed before and 
after each hydrophone deployment. If the measurement system employs 
filters via hardware or software (e.g., high-pass, low-pass, etc.), 
which is not already accounted for by the calibration, the filter 
performance (i.e., the filter's frequency response) must be known, 
reported, and the data corrected before analysis;
    (v) LOA Holder must be prepared with additional equipment 
(hydrophones, recording devices, hydrophone calibrators, cables, 
batteries, etc.), which exceeds the amount of equipment necessary to 
perform the measurements, such that technical issues can be mitigated 
before measurement;
    (vi) LOA Holder must submit interim SFV reports within 48 hours 
after each foundation is measured (see Sec.  217.345(g) for interim and 
final reporting requirements);
    (vii) If any of the interim SFV measurement reports submitted for 
the first three monopiles exceed the modeled distances to NMFS marine 
mammal Level A harassment and Level B harassment thresholds assuming 
10-dB attenuation, then LOA Holder must implement additional sound 
attenuation measures on all subsequent foundations. LOA Holder must 
also increase clearance and shutdown zone sizes to those identified by 
NMFS until SFV measurements on at least three additional foundations 
demonstrate acoustic distances to harassment thresholds meet or are 
less than those modeled assuming 10 dB of attenuation. LOA Holder must 
optimize the sound attenuation systems (e.g., ensure hose maintenance, 
pressure testing, etc.) to meet noise levels modeled, assuming

[[Page 580]]

10-dB attenuation, within three piles or else foundation installation 
activities must cease until NMFS and LOA Holder can evaluate the 
situation and ensure future piles do not exceed noise levels modeled 
assuming 10-dB attenuation;
    (viii) If, after additional measurements conducted pursuant to 
requirements of paragraph (14)(vii) of this section, acoustic 
measurements indicate that ranges to isopleths corresponding to the 
Level A harassment and Level B harassment thresholds are less than the 
ranges predicted by modeling (assuming 10-dB attenuation), LOA Holder 
may request a modification of the clearance and shutdown zones from the 
NMFS Office of Protected Resources. For NMFS Office of Protected 
Resources to consider a modification request for reduced zone sizes, 
LOA Holder must have conducted SFV measurements on an additional three 
foundations (for either/or monopile and jackets) and ensure that 
subsequent foundations would be installed under conditions that are 
predicted to produce smaller harassment zones than those modeled 
assuming 10 dB of attenuation;
    (ix) LOA Holder must conduct SFV measurements as described in c(14) 
upon commencement of turbine operations to estimate turbine operational 
source levels, in accordance with a NMFS-approved Foundation 
Installation Pile Driving SFV Plan. SFV must be conducted in the same 
manner as previously described in Sec.  217.304(c)(14), with 
appropriate adjustments to measurement distances, number of 
hydrophones, and hydrophone sensitivities being made, as necessary; and
    (x) LOA Holder must submit a SFV Plan to NMFS Office of Protected 
Resources for review and approval at least 180 days prior to planned 
start of foundation installation activities and abide by the Plan if 
approved. At minimum, the SFV Plan must describe how LOA Holder would 
ensure that the first three monopile foundation/entire jacket 
foundation (inclusive of all pin piles for a jacket foundation) 
installation sites selected for SFV measurements are representative of 
the rest of the monopile and/or jacket foundation installation sites 
such that future pile installation events are anticipated to produce 
similar sound levels to those piles measured. In the case that these 
sites/scenarios are not determined to be representative of all other 
pile installation sites, LOA Holder must include information in the SFV 
Plan on how additional sites/scenarios would be selected for SFV 
measurements. The SFV Plan must also include methodology for 
collecting, analyzing, and preparing SFV measurement data for 
submission to NMFS Office of Protected Resources and describe how the 
effectiveness of the sound attenuation methodology would be evaluated 
based on the results. SFV for pile driving may not occur until NMFS 
approves the SFV Plan for this activity.
    (15) LOA Holder must submit a Foundation Installation Pile Driving 
Marine Mammal Monitoring Plan to NMFS Office of Protected Resources for 
review and approval at least 180 days prior to planned start of pile 
driving and abide by the Plan if approved. LOA Holder must obtain both 
NMFS Office of Protected Resources and NMFS Greater Atlantic Regional 
Fisheries Office Protected Resources Division's concurrence with this 
Plan prior to the start of any pile driving. The Plan must include a 
description of all monitoring equipment and PAM and PSO protocols 
(including number and location of PSOs) for all pile driving. No 
foundation pile installation can occur without NMFS' approval of the 
Plan.
    (16) LOA Holder must submit a Passive Acoustic Monitoring Plan (PAM 
Plan) to NMFS Office of Protected Resources for review and approval at 
least 180 days prior to the planned start of foundation installation 
activities (impact pile driving) and abide by the Plan if approved. The 
PAM Plan must include a description of all proposed PAM equipment, 
address how the proposed passive acoustic monitoring must follow 
standardized measurement, processing methods, reporting metrics, and 
metadata standards for offshore wind as described in ``NOAA and BOEM 
Minimum Recommendations for Use of Passive Acoustic Listening Systems 
in Offshore Wind Energy Development Monitoring and Mitigation 
Programs'' (2021). The Plan must describe all proposed PAM equipment, 
procedures, and protocols including proof that vocalizing North 
Atlantic right whales will be detected within the clearance and 
shutdown zones. No pile installation can occur if LOA Holder's PAM Plan 
does not receive approval from NMFS Office of Protected Resources and 
NMFS Greater Atlantic Regional Fisheries Office Protected Resources 
Division.
    (d) HRG surveys. The following requirements apply to HRG surveys 
operating sub-bottom profilers (SBPs) (i.e., boomers, sparkers, and 
Compressed High Intensity Radiated Pulse (CHIRPS)):
    (1) LOA Holder must establish and implement clearance and shutdown 
zones for HRG surveys using visual monitoring, as described in 
paragraph (d) of this section;
    (2) LOA Holder must utilize PSO(s), as described in Sec.  
217.345(f);
    (3) SBPs (hereinafter referred to as ``acoustic sources'') must be 
deactivated when not acquiring data or preparing to acquire data, 
except as necessary for testing. Acoustic sources must be used at the 
lowest practicable source level to meet the survey objective, when in 
use, and must be turned off when they are not necessary for the survey;
    (4) LOA Holder is required to ramp-up acoustic sources prior to 
commencing full power, unless the equipment operates on a binary on/off 
switch, and ensure visual clearance zones are observable (e.g., not 
obscured from observation by darkness, rain, fog, etc.) and clear of 
marine mammals, as determined by the Lead PSO, for at least 30 minutes 
immediately prior to the initiation of survey activities using acoustic 
sources specified in the LOA. Ramp-up and activation must be delayed if 
a marine mammal(s) enters its respective shutdown zone. Ramp-up and 
activation may only be reinitiated if the animal(s) has been observed 
exiting its respective shutdown zone or until 15 minutes for small 
odontocetes and pinnipeds, and 30 minutes for all other species, has 
elapsed with no further sightings;
    (5) Prior to a ramp-up procedure starting or activating acoustic 
sources, the acoustic source operator (operator) must notify a 
designated PSO of the planned start of ramp-up as agreed upon with the 
Lead PSO. The notification time should not be less than 60 minutes 
prior to the planned ramp-up or activation in order to allow the PSOs 
time to monitor the clearance zone(s) for 30 minutes prior to the 
initiation of ramp-up or activation (pre-start clearance). During this 
30-minute pre-start clearance period, the entire applicable clearance 
zones must be visible, except as indicated in paragraph (d)(11) of this 
section;
    (6) Ramp-ups must be scheduled so as to minimize the time spent 
with the source activated;
    (7) A PSO conducting pre-start clearance observations must be 
notified again immediately prior to reinitiating ramp-up procedures and 
the operator must receive confirmation from the PSO to proceed;
    (8) LOA Holder must implement a 30-minute clearance period of the 
clearance zones immediately prior to the commencing of the survey or 
when there is more than a 30-minute break in survey activities or PSO 
monitoring. A clearance period is a period when no marine mammals are 
detected in the relevant zone;

[[Page 581]]

    (9) If a marine mammal is observed within a clearance zone during 
the clearance period, ramp-up or acoustic surveys may not begin until 
the animal(s) has been observed voluntarily exiting its respective 
clearance zone or until a specific time period has elapsed with no 
further sighting. The specific time period is 15 minutes for small 
odontocetes and pinnipeds, and 30 minutes for all other species;
    (10) In any case when the clearance process has begun in conditions 
with good visibility, including via the use of night vision equipment 
(infrared (IR)/thermal camera), and the Lead PSO has determined that 
the clearance zones are clear of marine mammals, survey operations 
would be allowed to commence (i.e., no delay is required) despite 
periods of inclement weather and/or loss of daylight. Ramp-up may occur 
at times of poor visibility, including nighttime, if appropriate visual 
monitoring has occurred with no detections of marine mammals in the 30 
minutes prior to beginning ramp-up;
    (11) Once the survey has commenced, LOA Holder must shut down 
acoustic sources if a marine mammal enters a respective shutdown zone, 
except in cases when the shutdown zones become obscured for brief 
periods due to inclement weather, survey operations would be allowed to 
continue (i.e., no shutdown is required) so long as no marine mammals 
have been detected. The shutdown requirement does not apply to small 
delphinids of the following genera: Delphinus, Stenella, 
Lagenorhynchus, and Tursiops. If there is uncertainty regarding the 
identification of a marine mammal species (i.e., whether the observed 
marine mammal belongs to one of the delphinid genera for which shutdown 
is waived), the PSOs must use their best professional judgment in 
making the decision to call for a shutdown. Shutdown is required if a 
delphinid that belongs to a genus other than those specified in this 
paragraph (d)(11) is detected in the shutdown zone;
    (12) If an acoustic source has been shut down due to the presence 
of a marine mammal, the use of an acoustic source may not commence or 
resume until the animal(s) has been confirmed to have left the Level B 
harassment zone or until a full 15 minutes (for small odontocetes and 
seals) or 30 minutes (for all other marine mammals) have elapsed with 
no further sighting;
    (13) LOA Holder must immediately shut down any acoustic source if a 
marine mammal is sighted entering or within its respective shutdown 
zones. If there is uncertainty regarding the identification of a marine 
mammal species (i.e., whether the observed marine mammal belongs to one 
of the delphinid genera for which shutdown is waived), the PSOs must 
use their best professional judgment in making the decision to call for 
a shutdown. Shutdown is required if a delphinid that belongs to a genus 
other than those specified in paragraph (d)(11) of this section is 
detected in the shutdown zone; and
    (14) If an acoustic source is shut down for a period longer than 30 
minutes, all clearance and ramp-up procedures must be initiated. If an 
acoustic source is shut down for reasons other than mitigation (e.g., 
mechanical difficulty) for less than 30 minutes, acoustic sources may 
be activated again without ramp-up only if PSOs have maintained 
constant observation and no additional detections of any marine mammal 
occurred within the respective shutdown zones.
    (e) Fisheries monitoring surveys. The following measures apply to 
fishery monitoring surveys:
    (1) Survey gear must be deployed as soon as possible once the 
vessel arrives on station. Gear must not be deployed if there is a risk 
of interaction with marine mammals. Gear may be deployed after 15 
minutes of no marine mammal sightings within 1 nautical mile (nmi; 
1,852 m) of the sampling station;
    (2) LOA Holder and its cooperating institutions, contracted 
vessels, or commercially hired captains must implement the following 
``move-on'' rule: If marine mammals are sighted within 1 nmi of the 
planned location and 15 minutes before gear deployment, then LOA Holder 
and its cooperating institutions, contracted vessels, or commercially 
hired captains, as appropriate, must move the vessel away from the 
marine mammal to a different section of the sampling area. If, after 
moving on, marine mammals are still visible from the vessel, LOA Holder 
and its cooperating institutions, contracted vessels, or commercially 
hired captains must move again or skip the station;
    (3) If a marine mammal is at risk of interacting with or becoming 
entangled in the gear after the gear is deployed or set, all gear must 
be immediately removed from the water. If marine mammals are sighted 
before the gear is fully removed from the water, the vessel must slow 
its speed and maneuver the vessel away from the animals to minimize 
potential interactions with the observed animal;
    (4) LOA Holder must maintain visual marine mammal monitoring effort 
during the entire period of time that gear is in the water (i.e., 
throughout gear deployment, fishing, and retrieval);
    (5) All fisheries monitoring gear must be fully cleaned and 
repaired (if damaged) before each use/deployment;
    (6) LOA Holder's fixed gear must comply with the Atlantic Large 
Whale Take Reduction Plan regulations at 50 CFR 229.32 during fisheries 
monitoring surveys;
    (7) All gear must be emptied as close to the deck/sorting area and 
as quickly as possible after retrieval;
    (8) During any survey that uses vertical lines, buoy lines must be 
weighted and must not float at the surface of the water and all 
groundlines must consist of sinking lines. All groundlines must be 
composed entirely of sinking lines. Buoy lines must utilize weak links. 
Weak links must break cleanly leaving behind the bitter end of the 
line. The bitter end of the line must be free of any knots when the 
weak link breaks. Splices are not considered to be knots. The 
attachment of buoys, toggles, or other floatation devices to 
groundlines is prohibited;
    (9) All in-water survey gear, including buoys, must be properly 
labeled with the scientific permit number or identification as LOA 
Holder's research gear. All labels and markings on the gear, buoys, and 
buoy lines must also be compliant with the Atlantic Large Whale Take 
Reduction Plan regulations at 50 CFR 229.32, and all buoy markings must 
comply with instructions received by the NOAA Greater Atlantic Regional 
Fisheries Office Protected Resources Division;
    (10) All survey gear must be removed from the water whenever not in 
active survey use (i.e., no wet storage); and
    (11) All reasonable efforts, that do not compromise human safety, 
must be undertaken to recover gear.


Sec.  217.345  Monitoring and reporting requirements.

    (a) Protected species observer (PSO) and passive acoustic 
monitoring (PAM) operator qualifications. LOA Holder must implement the 
following measures applicable to PSOs and PAM operators:
    (1) LOA Holder must use independent, NMFS-approved PSOs and PAM 
operators, meaning that the PSOs and PAM operators must be employed by 
a third-party observer provider, must have no tasks other than to 
conduct observational effort, collect data, and communicate with and 
instruct relevant crew with regard to the presence of protected species 
and mitigation requirements;
    (2) All PSOs and PAM operators must have successfully attained a 
bachelor's degree from an accredited college or

[[Page 582]]

university with a major in one of the natural sciences, a minimum of 30 
semester hours or equivalent in the biological sciences, and at least 
one undergraduate course in math or statistics. The educational 
requirements may be waived if the PSO or PAM operator has acquired the 
relevant skills through a suitable amount of alternate experience. 
Requests for such a waiver must be submitted to NMFS Office of 
Protected Resources and must include written justification containing 
alternative experience. Alternate experience that may be considered 
includes, but is not limited to previous work experience conducting 
academic, commercial, or government-sponsored marine mammal visual and/
or acoustic surveys, or previous work experience as a PSO/PAM operator;
    (3) PSOs must have visual acuity in both eyes (with correction of 
vision being permissible) sufficient enough to discern moving targets 
on the water's surface with the ability to estimate the target size and 
distance (binocular use is allowable); ability to conduct field 
observations and collect data according to the assigned protocols; 
sufficient training, orientation, or experience with the construction 
operation to provide for personal safety during observations; writing 
skills sufficient to document observations, including but not limited 
to, the number and species of marine mammals observed, the dates and 
times when in-water construction activities were conducted, the dates 
and time when in-water construction activities were suspended to avoid 
potential incidental take of marine mammals from construction noise 
within a defined shutdown zone, and marine mammal behavior; and the 
ability to communicate orally, by radio, or in-person, with project 
personnel to provide real-time information on marine mammals observed 
in the area;
    (4) All PSOs must be trained in northwestern Atlantic Ocean marine 
mammal identification and behaviors and must be able to conduct field 
observations and collect data according to assigned protocols. 
Additionally, PSOs must have the ability to work with all required and 
relevant software and equipment necessary during observations (as 
described in paragraphs (b)(6) and (7) of this section;
    (5) All PSOs and PAM operators must successfully complete a 
relevant training course within the last 5 years, including obtaining a 
certificate of course completion;
    (6) PSOs and PAM operators are responsible for obtaining NMFS' 
approval. NMFS may approve PSOs and PAM operators as conditional or 
unconditional. A conditionally approved PSO or PAM operator may be one 
who has completed training in the last 5 years but has not yet attained 
the requisite field experience. An unconditionally approved PSO or PAM 
operator is one who has completed training within the last 5 years and 
attained the necessary experience (i.e., demonstrate experience with 
monitoring for marine mammals at clearance and shutdown zone sizes 
similar to those produced during the respective activity). Lead PSO or 
PAM operators must be unconditionally approved and have a minimum of 90 
days in a northwestern Atlantic Ocean offshore environment performing 
the role (either visual or acoustic), with the conclusion of the most 
recent relevant experience not more than 18 months previous. A 
conditionally approved PSO or PAM operator must be paired with an 
unconditionally approved PSO or PAM operator;
    (7) PSOs for HRG surveys may be unconditionally or conditionally 
approved. PSOs and PAM operators for foundation installation activities 
must be unconditionally approved;
    (8) At least one on-duty PSO and PAM operator, where applicable, 
for each activity (e.g., impact pile driving, vibratory pile driving, 
and HRG surveys) must be designated as the Lead PSO or Lead PAM 
operator;
    (9) LOA Holder must submit NMFS previously approved PSOs and PAM 
operators to NMFS Office of Protected Resources for review and 
confirmation of their approval for specific roles at least 30 days 
prior to commencement of the activities requiring PSOs/PAM operators or 
15 days prior to when new PSOs/PAM operators are required after 
activities have commenced;
    (10) For prospective PSOs and PAM operators not previously 
approved, or for PSOs and PAM operators whose approval is not current, 
LOA Holder must submit resumes for approval at least 60 days prior to 
PSO and PAM operator use. Resumes must include information related to 
relevant education, experience, and training, including dates, 
duration, location, and description of prior PSO or PAM operator 
experience. Resumes must be accompanied by relevant documentation of 
successful completion of necessary training;
    (11) PAM operators are responsible for obtaining NMFS approval. To 
be approved as a PAM operator, the person must meet the following 
qualifications: The PAM operator must demonstrate that they have prior 
experience with real-time acoustic detection systems and/or have 
completed specialized training for operating PAM systems and detecting 
and identifying Atlantic Ocean marine mammals sounds, in particular: 
North Atlantic right whale sounds, humpback whale sounds, and how to 
deconflict them from similar North Atlantic right whale sounds, and 
other co-occurring species' sounds in the area including sperm whales; 
must be able to distinguish between whether a marine mammal or other 
species sound is detected, possibly detected, or not detected, and 
similar terminology must be used across companies/projects; Where 
localization of sounds or deriving bearings and distance are possible, 
the PAM operators need to have demonstrated experience in using this 
technique; PAM operators must be independent observers (i.e., not 
construction personnel); PAM operators must demonstrate experience with 
relevant acoustic software and equipment; PAM operators must have the 
qualifications and relevant experience/training to safely deploy and 
retrieve equipment and program the software, as necessary; PAM 
operators must be able to test software and hardware functionality 
prior to operation; and PAM operators must have evaluated their 
acoustic detection software using the PAM Atlantic baleen whale 
annotated data set available at National Centers for Environmental 
Information (NCEI) and provide evaluation/performance metric;
    (12) PAM operators must be able to review and classify acoustic 
detections in real-time (prioritizing North Atlantic right whales and 
noting detection of other cetaceans) during the real-time monitoring 
periods;
    (13) PSOs may work as PAM operators and vice versa, pending NMFS-
approval; however, they may only perform one role at any time and must 
not exceed work time restrictions, which must be tallied cumulatively; 
and
    (14) All PSOs and PAM operators must complete a Permits and 
Environmental Compliance Plan training and a 2-day refresher session 
that must be held with the PSO provider and Project compliance 
representative(s) prior to the start of in-water project activities 
(e.g., HRG survey, foundation installation, etc.).
    (b) General PSO and PAM operator requirements. The following 
measures apply to PSOs and PAM operators and must be implemented by LOA 
Holder:
    (1) PSOs must monitor for marine mammals prior to, during, and 
following impact pile driving and HRG surveys that use sub-bottom 
profilers (with specific monitoring durations and needs described in 
paragraphs (c) through (f) of this section, respectively).

[[Page 583]]

Monitoring must be done while free from distractions and in a 
consistent, systematic, and diligent manner;
    (2) For foundation installation, PSOs must visually clear (i.e., 
confirm no observations of marine mammals) the entire minimum 
visibility zone for a full 30 minutes immediately prior to commencing 
activities. For HRG surveys, which do not have a minimum visibility 
zone, the entire clearance zone must be visually cleared and as much of 
the Level B harassment zone as possible;
    (3) All PSOs must be located at the best vantage point(s) on any 
platform, as determined by the Lead PSO, in order to obtain 360-degree 
visual coverage of the entire clearance and shutdown zones around the 
activity area, and as much of the Level B harassment zone as possible. 
PAM operators may be located on a vessel or remotely on-shore, the PAM 
operator(s) must assist PSOs in ensuring full coverage of the clearance 
and shutdown zones. The PAM operator must monitor to and past the 
clearance zone for large whales;
    (4) All on-duty PSOs must remain in real-time contact with the on-
duty PAM operator(s), PAM operators must immediately communicate all 
acoustic detections of marine mammals to PSOs, including any 
determination regarding species identification, distance, and bearing 
(where relevant) relative to the pile being driven and the degree of 
confidence (e.g., possible, probable detection) in the determination. 
All on-duty PSOs and PAM operator(s) must remain in contact with the 
on-duty construction personnel responsible for implementing mitigations 
(e.g., delay to pile driving) to ensure communication on marine mammal 
observations can easily, quickly, and consistently occur between all 
on-duty PSOs, PAM operator(s), and on-water Project personnel;
    (5) The PAM operator must inform the Lead PSO(s) on duty of animal 
detections approaching or within applicable ranges of interest to the 
activity occurring via the data collection software system (i.e., 
Mysticetus or similar system) who must be responsible for requesting 
that the designated crewmember implement the necessary mitigation 
procedures (i.e., delay);
    (6) PSOs must use high magnification (25x) binoculars, standard 
handheld (7x) binoculars, and the naked eye to search continuously for 
marine mammals. During foundation installation, at least two PSOs on 
the pile driving vessel must be equipped with functional Big Eye 
binoculars (e.g., 25 * 150; 2.7 view angle; individual ocular focus; 
height control); these must be pedestal mounted on the deck at the best 
vantage point that provides for optimal sea surface observation and PSO 
safety. PAM operators must have the appropriate equipment (i.e., a 
computer station equipped with a data collection software system 
available wherever they are stationed) and use a NMFS-approved PAM 
system to conduct monitoring. PAM systems are approved through the PAM 
Plan as described in Sec.  217.344(c)(17); and
    (7) PSOs and PAM operators must not exceed 4 consecutive watch 
hours on duty at any time, must have a 2-hour (minimum) break between 
watches, and must not exceed a combined watch schedule of more than 12 
hours in a 24-hour period. If the schedule includes PSOs and PAM 
operators on-duty for 2-hour shifts, a minimum 1-hour break between 
watches must be allowed.
    (c) PSO and PAM operator requirements during WTG, OSS, and Met 
Tower foundation installation. The following measures apply to PSOs and 
PAM operators during WTG, OSS, and Met tower foundation installation 
and must be implemented by LOA Holder:
    (1) PSOs and PAM operator(s), using a NMFS-approved PAM system, 
must monitor for marine mammals 60 minutes prior to, during, and 30 
minutes following all pile driving activities. If PSOs cannot visually 
monitor the minimum visibility zone prior to impact pile driving at all 
times using the equipment described in paragraphs (b)(6) and (7) of 
this section, pile driving operations must not commence or must 
shutdown if they are currently active;
    (2) At least three on-duty PSOs must be stationed and observing 
from the activity platform during impact pile driving and at least 
three on-duty PSOs must be stationed on each dedicated PSO vessel. 
Concurrently, at least one PAM operator per acoustic data stream 
(equivalent to the number of acoustic buoys) must be actively 
monitoring for marine mammals 60 minutes before, during, and 30 minutes 
after impact pile driving in accordance with a NMFS-approved PAM Plan; 
and
    (3) LOA Holder must conduct PAM for at least 24 hours immediately 
prior to pile driving activities. The PAM operator must review all 
detections from the previous 24-hour period immediately prior to pile 
driving activities.
    (d) PSO requirements during HRG surveys. The following measures 
apply to PSOs during HRG surveys using acoustic sources that have the 
potential to result in harassment and must be implemented by LOA 
Holder:
    (1) At least one PSO must be on active duty monitoring during HRG 
surveys conducted during daylight (i.e., from 30 minutes prior to civil 
sunrise through 30 minutes following civil sunset) and two PSOs during 
nighttime surveying (if it occurs);
    (2) PSOs on HRG vessels must begin monitoring 30 minutes prior to 
activating acoustic sources, during the use of these acoustic sources, 
and for 30 minutes after use of these acoustic sources has ceased;
    (3) Any observations of marine mammals must be communicated to PSOs 
on all nearby survey vessels during concurrent HRG surveys; and
    (4) During daylight hours when survey equipment is not operating, 
LOA Holder must ensure that visual PSOs conduct, as rotation schedules 
allow, observations for comparison of sighting rates and behavior with 
and without use of the specified acoustic sources.
    (e) Monitoring requirements during fisheries monitoring surveys. 
The following measures apply during fisheries monitoring surveys and 
must be implemented by LOA Holder:
    (1) All captains and crew conducting fishery surveys must be 
trained in marine mammal detection and identification; and
    (2) Marine mammal monitoring must be conducted within 1 nmi from 
the planned survey location by the trained captain and/or a member of 
the scientific crew for 15 minutes prior to deploying gear, throughout 
gear deployment and use, and for 15 minutes after haul back.
    (f) Reporting. LOA Holder must comply with the following reporting 
measures:
    (1) Prior to initiation of any on-water project activities, LOA 
Holder must demonstrate in a report submitted to NMFS Office of 
Protected Resources that all required training for LOA Holder personnel 
(including the vessel crews, vessel captains, PSOs, and PAM operators) 
has been completed.
    (2) LOA Holder must use a standardized reporting system during the 
effective period of the LOA. All data collected related to the Project 
must be recorded using industry-standard software that is installed on 
field laptops and/or tablets. Unless stated otherwise, all reports must 
be submitted to NMFS Office of Protected Resources 
(<a href="/cdn-cgi/l/email-protection#4d1d1f6304191d630022232439223f24232a1f283d223f393e0d23222c2c632a223b"><span class="__cf_email__" data-cfemail="3161631f7865611f7c5e5f58455e43585f566354415e434542715f5e50501f565e47">[email protected]</span></a>), dates must be in MM/DD/YYYY 
format, and location information must be provided in Decimal Degrees 
and with the coordinate system information (e.g., NAD83, WGS84, etc.).
    (3) For all visual monitoring efforts and marine mammal sightings, 
the

[[Page 584]]

following information must be collected and reported to NMFS Office of 
Protected Resources: the date and time that monitored activity begins 
or ends; the construction activities occurring during each observation 
period; the watch status (i.e., sighting made by PSO on/off effort, 
opportunistic, crew, alternate vessel/platform); the PSO who sighted 
the animal; the time of sighting; the weather parameters (e.g., wind 
speed, percent cloud cover, visibility); the water conditions (e.g., 
Beaufort sea state, tide state, water depth); all marine mammal 
sightings, regardless of distance from the construction activity; 
species (or lowest possible taxonomic level possible); the pace of the 
animal(s); the estimated number of animals (minimum/maximum/high/low/
best); the estimated number of animals by cohort (e.g., adults, 
yearlings, juveniles, calves, group composition, etc.); the description 
(i.e., as many distinguishing features as possible of each individual 
seen, including length, shape, color, pattern, scars or markings, shape 
and size of dorsal fin, shape of head, and blow characteristics); the 
description of any marine mammal behavioral observations (e.g., 
observed behaviors such as feeding or traveling) and observed changes 
in behavior, including an assessment of behavioral responses thought to 
have resulted from the specific activity; the animal's closest distance 
and bearing from the pile being driven or specified HRG equipment and 
estimated time entered or spent within the Level A harassment and/or 
Level B harassment zone(s); the activity at time of sighting (e.g., 
impact pile driving, construction survey), use of any noise attenuation 
device(s), and specific phase of activity (e.g., ramp-up of HRG 
equipment, HRG acoustic source on/off, soft-start for pile driving, 
active pile driving, etc.); the marine mammal occurrence in Level A 
harassment or Level B harassment zones; the description of any 
mitigation-related action implemented, or mitigation-related actions 
called for but not implemented, in response to the sighting (e.g., 
delay, shutdown, etc.) and time and location of the action; other human 
activity in the area, and; other applicable information, as required in 
any LOAs issued under Sec.  217.346.
    (4) LOA Holder must compile and submit weekly reports during 
foundation installation to NMFS Office of Protected Resources that 
document the daily start and stop of all pile driving associated with 
the Project; the start and stop of associated observation periods by 
PSOs; details on the deployment of PSOs; a record of all detections of 
marine mammals (acoustic and visual); any mitigation actions (or if 
mitigation actions could not be taken, provide reasons why); and 
details on the noise attenuation system(s) used and its performance. 
Weekly reports are due on Wednesday for the previous week (Sunday to 
Saturday) and must include the information required under this section. 
The weekly report must also identify which turbines become operational 
and when (a map must be provided). Once all foundation pile 
installation is completed, weekly reports are no longer required by LOA 
Holder.
    (5) LOA Holder must compile and submit monthly reports to NMFS 
Office of Protected Resources during foundation installation that 
include a summary of all information in the weekly reports, including 
project activities carried out in the previous month, vessel transits 
(number, type of vessel, MMIS number, and route), number of piles 
installed, all detections of marine mammals, and any mitigative action 
taken. Monthly reports are due on the 15th of the month for the 
previous month. The monthly report must also identify which turbines 
become operational and when (a map must be provided). Full PAM 
detection data and metadata must also be submitted monthly on the 15th 
of every month for the previous month via the webform on the NMFS North 
Atlantic Right Whale Passive Acoustic Reporting System website at 
https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates.
    (6) LOA Holder must submit a draft annual report to NMFS Office of 
Protected Resources no later than 90 days following the end of a given 
calendar year. LOA Holder must provide a final report within 30 days 
following resolution of NMFS' comments on the draft report. The draft 
and final reports must detail the following: the total number of marine 
mammals of each species/stock detected and how many were within the 
designated Level A harassment and Level B harassment zone(s) with 
comparison to authorized take of marine mammals for the associated 
activity type; marine mammal detections and behavioral observations 
before, during, and after each activity; what mitigation measures were 
implemented (i.e., number of shutdowns or clearance zone delays, etc.) 
or, if no mitigative actions was taken, why not; operational details 
(i.e., days and duration of impact and vibratory pile driving, days, 
and amount of HRG survey effort, etc.); any PAM systems used; the 
results, effectiveness, and which noise attenuation systems were used 
during relevant activities (i.e., impact pile driving); summarized 
information related to situational reporting; and any other important 
information relevant to the Project, including additional information 
that may be identified through the adaptive management process.
    (7) LOA Holder must submit its draft 5-year report to NMFS Office 
of Protected Resources on all visual and acoustic monitoring conducted 
within 90 calendar days of the completion of activities occurring under 
the LOA. At a minimum, the draft and final 5-year report must include: 
the total number (annually and across all 5 years) of marine mammals of 
each species/stock detected and how many were detected within the 
designated Level A harassment and Level B harassment zone(s) with 
comparison to authorized take of marine mammals for the associated 
activity type; a summary table(s) indicating the amount of each 
activity type (e.g., pile installation, HRG) completed in each of the 5 
years and total; GIS shapefile(s) of the final location of all piles, 
cable routes, and other permanent structures including an indication of 
what year installed and began operating; GIS shapefile of all North 
Atlantic right whale sightings, including dates and group sizes; a 5-
year summary and evaluation of all SFV data collected; a 5-year summary 
and evaluation of all PAM data collected; a 5-year summary and 
evaluation of marine mammal behavioral observations; a 5-year summary 
and evaluation of mitigation and monitoring implementation and 
effectiveness; a list of recommendations to inform environmental 
compliance assessments for future offshore wind actions. A 5-year 
report must be prepared and submitted within 60 calendar days following 
receipt of any NMFS Office of Protected Resources comments on the draft 
report. If no comments are received from NMFS Office of Protected 
Resources within 60 calendar days of NMFS Office of Protected Resources 
receipt of the draft report, the report shall be considered final.
    (8) For those foundation piles requiring SFV measurements, LOA 
Holder must provide the initial results of the SFV measurements to NMFS 
Office of Protected Resources in an interim report after each 
foundation installation event as soon as they are available and prior 
to a subsequent foundation installation, but no later than 48 hours 
after each completed foundation installation event. The report must 
include, at minimum: hammer energies/schedule used during

[[Page 585]]

pile driving, including, the total number of strikes and the maximum 
hammer energy; the model-estimated acoustic ranges 
(R<INF>95</INF><not-eq>) to compare with the real-world sound field 
measurements; peak sound pressure level (SPL<INF>pk</INF>), root-mean-
square sound pressure level that contains 90 percent of the acoustic 
energy (SPL<INF>rms</INF>), and sound exposure level (SEL, in single 
strike for pile driving, SEL<INF>ss,</INF>), for each hydrophone, 
including at least the maximum, arithmetic mean, minimum, median (L50) 
and L5 (95 percent exceedance) statistics for each metric; estimated 
marine mammal Level A harassment and Level B harassment isopleths, 
calculated using the maximum-over-depth L5 (95 percent exceedance 
level, maximum of both hydrophones) of the associated sound metric; 
comparison of modeled results assuming 10-dB attenuation against the 
measured marine mammal Level A harassment and Level B harassment 
acoustic isopleths; estimated transmission loss coefficients; pile 
identifier name, location of the pile and each hydrophone array in 
latitude/longitude; depths of each hydrophone; one-third-octave band 
single strike SEL spectra; if filtering is applied, full filter 
characteristics must be reported; and hydrophone specifications 
including the type, model, and sensitivity. LOA Holder must also report 
any immediate observations which are suspected to have a significant 
impact on the results including but not limited to: observed noise 
mitigation system issues, obstructions along the measurement transect, 
and technical issues with hydrophones or recording devices. If any in-
situ calibration checks for hydrophones reveal a calibration drift 
greater than 0.75 dB, pistonphone calibration checks are inconclusive, 
or calibration checks are otherwise not effectively performed, LOA 
Holder must indicate full details of the calibration procedure, 
results, and any associated issues in the 48-hour interim reports.
    (9) The final results of SFV measurements from each foundation 
installation must be submitted as soon as possible, but no later than 
90 days following completion of each event's SFV measurements. The 
final reports must include all details prescribed above for the interim 
report as well as, at minimum, the following: the peak sound pressure 
level (SPL<INF>pk</INF>), the root-mean-square sound pressure level 
that contains 90 percent of the acoustic energy (SPL<INF>rms</INF>), 
the single strike sound exposure level (SEL<INF>ss</INF>), the 
integration time for SPL<INF>rms</INF>, the spectrum, and the 24-hour 
cumulative SEL extrapolated from measurements at all hydrophones. The 
final report must also include at least the maximum, mean, minimum, 
median (L<INF>50</INF>) and L<INF>5</INF> (95 percent exceedance) 
statistics for each metric; the SEL and SPL power spectral density and/
or one-third octave band levels (usually calculated as decidecade band 
levels) at the receiver locations should be reported; the sound levels 
reported must be in median, arithmetic mean, and L<INF>5</INF> (95 
percent exceedance) (i.e., average in linear space), and in dB; range 
of transmission loss coefficients; the local environmental conditions, 
such as wind speed, transmission loss data collected on-site (or the 
sound velocity profile); baseline pre- and post-activity ambient sound 
levels (broadband and/or within frequencies of concern); a description 
of depth and sediment type, as documented in the Construction and 
Operation Plan (COP), at the recording and foundation installation 
locations; the extents of the measured Level A harassment and Level B 
harassment zone(s); hammer energies required for pile installation and 
the number of strikes per pile; the hydrophone equipment and methods 
(i.e., recording device, bandwidth/sampling rate; distance from the 
pile where recordings were made; the depth of recording device(s)); a 
description of the SFV measurement hardware and software, including 
software version used, calibration data, bandwidth capability and 
sensitivity of hydrophone(s), any filters used in hardware or software, 
any limitations with the equipment, and other relevant information; the 
spatial configuration of the noise attenuation device(s) relative to 
the pile; a description of the noise abatement system and operational 
parameters (e.g., bubble flow rate, distance deployed from the pile, 
etc.), and any action taken to adjust the noise abatement system. A 
discussion which includes any observations which are suspected to have 
a significant impact on the results including but not limited to: 
observed noise mitigation system issues, obstructions along the 
measurement transect, and technical issues with hydrophones or 
recording devices.
    (10) If at any time during the project LOA Holder becomes aware of 
any issue or issues which may (to any reasonable subject-matter expert, 
including the persons performing the measurements and analysis) call 
into question the validity of any measured Level A harassment or Level 
B harassment isopleths to a significant degree, which were previously 
transmitted or communicated to NMFS Office of Protected Resources, LOA 
Holder must inform NMFS Office of Protected Resources within 1 business 
day of becoming aware of this issue or before the next pile is driven, 
whichever comes first.
    (11) If a North Atlantic right whale is acoustic detected at any 
time by a project-related PAM system, LOA Holder must ensure the 
detection is reported as soon as possible to NMFS, but no longer than 
24 hours after the detection via the ``24-hour North Atlantic right 
whale Detection Template'' (https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates). Calling the 
hotline is not necessary when reporting PAM detections via the 
template.
    (12) Full detection data, metadata, and location of recorders (or 
GPS tracks, if applicable) from all real-time hydrophones used for 
monitoring during construction must be submitted within 90 calendar 
days after pile driving has ended and instruments have been pulled from 
the water. Reporting must use the webform templates on the NMFS Passive 
Acoustic Reporting System website at https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates. Submit 
the completed data templates to <a href="/cdn-cgi/l/email-protection#e08e8d8693ce8e8583ce9081838d84819481a08e8f8181ce878f96"><span class="__cf_email__" data-cfemail="8ee0e3e8fda0e0ebeda0feefede3eaeffaefcee0e1efefa0e9e1f8">[email protected]</span></a>. The full 
acoustic recordings from all real-time hydrophones must also be sent to 
the National Centers for Environmental Information (NCEI) for archiving 
within 90 calendar days following completion of activities requiring 
PAM for mitigation. Submission details can be found at: https://www.ncei.noaa.gov/products/passive-acoustic-data.
    (13) LOA Holder must submit situational reports if the following 
circumstances occur (including all instances wherein an exemption is 
taken must be reported to NMFS Office of Protected Resources within 24 
hours):
    (i) If a North Atlantic right whale is observed at any time by PSOs 
or project personnel, LOA Holder must ensure the sighting is 
immediately (if not feasible, as soon as possible, and no longer than 
24 hours after the sighting) reported to NMFS and the Right Whale 
Sightings Advisory System (RWSAS). If in the Northeast Region (Maine to 
Virginia/North Carolina border) call (866-755-6622). If in the 
Southeast Region (North Carolina to Florida) call (877-WHALE-HELP or 
877-942-5343). If calling NMFS is not possible, reports can also be 
made to the U.S. Coast Guard via channel 16 or through the WhaleAlert 
app (https://www.whalealert.org). The sighting report must include the 
time, date, and location of the sighting,

[[Page 586]]

number of whales, animal description/certainty of sighting (provide 
photos/video if taken), Lease Area/project name, PSO/personnel name, 
PSO provider company (if applicable), and reporter's contact 
information.
    (ii) If a North Atlantic right whale is observed at any time by 
PSOs or project personnel, LOA Holder must submit a summary report to 
NMFS GARFO (<a href="/cdn-cgi/l/email-protection#98f6f5feebb6fff9eab6f1f6fbf1fcfdf6ecf9f4b5ecf9f3fdd8f6f7f9f9b6fff7ee"><span class="__cf_email__" data-cfemail="533d3e35207d3432217d3a3d303a37363d27323f7e27323836133d3c32327d343c25">[email protected]</span></a>) and NMFS Office of 
Protected Resources, and NMFS Northeast Fisheries Science Center 
(NEFSC; <a href="/cdn-cgi/l/email-protection#1678733864613865636460736f567879777738717960"><span class="__cf_email__" data-cfemail="a0cec58ed2d78ed3d5d2d6c5d9e0cecfc1c18ec7cfd6">[email protected]</span></a>) within 24 hours with the above 
information and the vessel/platform from which the sighting was made, 
activity the vessel/platform was engaged in at time of sighting, 
project construction and/or survey activity at the time of the sighting 
(e.g., pile driving, cable installation, HRG survey), distance from 
vessel/platform to sighting at time of detection, and any mitigation 
actions taken in response to the sighting.
    (iii) If an observation of a large whale occurs during vessel 
transit, LOA Holder must report the time, date, and location of the 
sighting; the vessel's activity, heading, and speed (knots); Beaufort 
sea state, water depth (meters), and visibility conditions; marine 
mammal species identification to the best of the observer's ability and 
any distinguishing characteristics; initial distance and bearing to 
marine mammal from vessel and closest point of approach; and any 
avoidance measures taken in response to the marine mammal sighting.
    (iv) In the event that personnel involved in the Project discover a 
stranded, entangled, injured, or dead marine mammal, LOA Holder must 
immediately report the observation to NMFS. If in the Greater Atlantic 
Region (Maine to Virginia) call the NMFS Greater Atlantic Stranding 
Hotline (866-755-6622); if in the Southeast Region (North Carolina to 
Florida), call the NMFS Southeast Stranding Hotline (877-942-5343). 
Separately, LOA Holder must report the incident to NMFS Office of 
Protected Resources (<a href="/cdn-cgi/l/email-protection#0151532f4855512f4c6e6f68756e73686f665364716e737572416f6e60602f666e77"><span class="__cf_email__" data-cfemail="aefefc80e7fafe80e3c1c0c7dac1dcc7c0c9fccbdec1dcdaddeec0c1cfcf80c9c1d8">[email protected]</span></a>) and, if in the 
Greater Atlantic region (Maine to Virginia), NMFS GARFO 
(<a href="/cdn-cgi/l/email-protection#b3ddded5c09dd4d2c19ddaddd0dad7d6ddc7d2df9ec7d2d8d6f3dddcd2d29dd4dcc5"><span class="__cf_email__" data-cfemail="026c6f64712c6563702c6b6c616b66676c76636e2f76636967426c6d63632c656d74">[email protected]</span></a>, <a href="/cdn-cgi/l/email-protection#afc1c2c9dc81c8cedd81dcdbddcec1cbc6c1c8efc1c0cece81c8c0d9"><span class="__cf_email__" data-cfemail="6806050e1b460f091a461b1c1a09060c01060f2806070909460f071e">[email protected]</span></a>) or, if 
in the Southeast region (North Carolina to Florida), NMFS Southeast 
Regional Office (SERO; <a href="/cdn-cgi/l/email-protection#453620262824282824293720352a373136052b2a24246b222a33"><span class="__cf_email__" data-cfemail="abd8cec8c6cac6c6cac7d9cedbc4d9dfd8ebc5c4caca85ccc4dd">[email protected]</span></a>) as soon as feasible. 
The report (via phone or email) must include contact (name, phone 
number, etc.), the time, date, and location of the first discovery (and 
updated location information if known and applicable); species 
identification (if known) or description of the animal(s) involved; 
condition of the animal(s) (including carcass condition if the animal 
is dead); observed behaviors of the animal(s), if alive; if available, 
photographs or video footage of the animal(s); and general 
circumstances under which the animal was discovered.
    (v) In the event of a vessel strike of a marine mammal by any 
vessel associated with the Project or if other project activities cause 
a non-auditory injury or death of a marine mammal, LOA Holder must 
immediately report the incident to NMFS. If in the Greater Atlantic 
Region (Maine to Virginia) call the NMFS Greater Atlantic Stranding 
Hotline (866-755-6622) and if in the Southeast Region (North Carolina 
to Florida) call the NMFS Southeast Stranding Hotline (877-942-5343). 
Separately, LOA Holder must immediately report the incident to NMFS 
Office of Protected Resources (<a href="/cdn-cgi/l/email-protection#89d9dba7c0ddd9a7c4e6e7e0fde6fbe0e7eedbecf9e6fbfdfac9e7e6e8e8a7eee6ff"><span class="__cf_email__" data-cfemail="6535374b2c31354b280a0b0c110a170c0b023700150a171116250b0a04044b020a13">[email protected]</span></a>) and, 
if in the Greater Atlantic region (Maine to Virginia), NMFS GARFO 
(<a href="/cdn-cgi/l/email-protection#dfb1b2b9acf1b8beadf1b6b1bcb6bbbab1abbeb3f2abbeb4ba9fb1b0bebef1b8b0a9"><span class="__cf_email__" data-cfemail="6d03000b1e430a0c1f4304030e04090803190c0140190c06082d03020c0c430a021b">[email protected]</span></a>, <a href="/cdn-cgi/l/email-protection#2d43404b5e034a4c5f035e595f4c434944434a6d43424c4c034a425b"><span class="__cf_email__" data-cfemail="d4bab9b2a7fab3b5a6faa7a0a6b5bab0bdbab394babbb5b5fab3bba2">[email protected]</span></a>) or, if 
in the Southeast region (North Carolina to Florida), NMFS SERO 
(<a href="/cdn-cgi/l/email-protection#82f1e7e1efe3efefe3eef0e7f2edf0f6f1c2ecede3e3ace5edf4"><span class="__cf_email__" data-cfemail="631006000e020e0e020f1106130c111710230d0c02024d040c15">[email protected]</span></a>). The report must include the time, date, 
and location of the incident; species identification (if known) or 
description of the animal(s) involved; vessel size and motor 
configuration (inboard, outboard, jet propulsion); vessel's speed 
leading up to and during the incident; vessel's course/heading and what 
operations were being conducted (if applicable); status of all sound 
sources in use; description of avoidance measures/requirements that 
were in place at the time of the strike and what additional measures 
were taken, if any, to avoid strike; environmental conditions (e.g., 
wind speed and direction, Beaufort sea state, cloud cover, visibility) 
immediately preceding the strike; estimated size and length of animal 
that was struck; description of the behavior of the marine mammal 
immediately preceding and following the strike; if available, 
description of the presence and behavior of any other marine mammals 
immediately preceding the strike; estimated fate of the animal (e.g., 
dead, injured but alive, injured and moving, blood or tissue observed 
in the water, status unknown, disappeared); and to the extent 
practicable, photographs or video footage of the animal(s). LOA Holder 
must immediately cease all on-water activities until the NMFS Office of 
Protected Resources is able to review the circumstances of the incident 
and determine what, if any, additional measures are appropriate to 
ensure compliance with the terms of the LOA. NMFS Office of Protected 
Resources may impose additional measures to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. LOA Holder may not 
resume their activities until notified by NMFS Office of Protected 
Resources.
    (14) LOA Holder must report any lost gear associated with the 
fishery surveys to the NOAA GARFO Protected Resources Division 
(<a href="/cdn-cgi/l/email-protection#57393a312479303625793e39343e33323923363b7a23363c32173938363679303821"><span class="__cf_email__" data-cfemail="fb95969d88d59c9a89d5929598929f9e958f9a97d68f9a909ebb95949a9ad59c948d">[email protected]</span></a>) as soon as possible or within 24 
hours of the documented time of missing or lost gear. This report must 
include information on any markings on the gear and any efforts 
undertaken or planned to recover the gear.


Sec.  217.346  Letter of Authorization.

    (a) To incidentally take marine mammals pursuant to this subpart, 
LOA Holder must apply for and obtain an LOA.
    (b) The LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed December 31, 2029, the expiration date of 
this subpart.
    (c) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by the LOA, LOA Holder must 
apply for and obtain a modification of the LOA as described in Sec.  
217.347.
    (d) The LOA must set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and on the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (e) Issuance of the LOA must be based on a determination that the 
level of taking must be consistent with the findings made for the total 
taking allowable under the regulations of this subpart.
    (f) Notice of issuance or denial of the LOA must be published in 
the Federal Register within 30 days of a determination.


Sec.  217.347  Modifications of Letter of Authorization.

    (a) The LOA issued under Sec. Sec.  217.342 and 217.346 or this 
section for the activity identified in Sec.  217.340 shall be modified 
upon request by LOA Holder, provided that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as

[[Page 587]]

those described and analyzed for this subpart (excluding changes made 
pursuant to the adaptive management provision in paragraph (c)(1) of 
this section); and
    (2) NMFS Office of Protected Resources determines that the 
mitigation, monitoring, and reporting measures required by the previous 
LOA under this subpart were implemented.
    (b) For a LOA modification request by the applicant that includes 
changes to the activity or the mitigation, monitoring, or reporting 
(excluding changes made pursuant to the adaptive management provision 
in paragraph (c)(1) of this section), the LOA shall be modified, 
provided that:
    (1) NMFS Office of Protected Resources determines that the changes 
to the activity or the mitigation, monitoring, or reporting do not 
change the findings made for the regulations in this subpart and do not 
result in more than a minor change in the total estimated number of 
takes (or distribution by species or years); and
    (2) NMFS Office of Protected Resources may, if appropriate, publish 
a notice of proposed LOA in the Federal Register, including the 
associated analysis of the change, and solicit public comment before 
issuing the LOA.
    (c) The LOA issued under Sec. Sec.  217.342 and 217.346 or this 
section for the activities identified in Sec.  217.340 may be modified 
by NMFS Office of Protected Resources under the following 
circumstances:
    (1) Through adaptive management, NMFS Office of Protected Resources 
may modify (including delete, modify, or add to) the existing 
mitigation, monitoring, or reporting measures (after consulting with 
the LOA Holder regarding the practicability of the modifications), if 
doing so creates a reasonable likelihood of more effectively 
accomplishing the goals of the mitigation and monitoring;
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in the LOA 
include, but are not limited to:
    (A) Results from LOA Holder's monitoring;
    (B) Results from other marine mammals and/or sound research or 
studies; and
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by the regulations in 
this subpart or subsequent LOA.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
Office of Protected Resources shall publish a notice of proposed LOA in 
the Federal Register and solicit public comment.
    (2) If NMFS Office of Protected Resources determines that an 
emergency exists that poses a significant risk to the well-being of the 
species or stocks of marine mammals specified in the LOA issued 
pursuant to Sec. Sec.  217.342 and 217.346 or this section, the LOA may 
be modified without prior notice or opportunity for public comment. 
Notice would be published in the Federal Register within 30 days of the 
action.


Sec. Sec.  217.348-217.349  [Reserved]

[FR Doc. 2023-27189 Filed 1-3-24; 8:45 am]
BILLING CODE 3510-22-P


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