# Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the New England Wind Project, Offshore Massachusetts

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2024-12085

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** June 21, 2024
- **Citation:** 89 FR 52222

## Text

DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 240524-0146]
RIN 0648-BL96
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the New England Wind Project, Offshore Massachusetts

AGENCY:

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

ACTION:

Final rule; notification of issuance of letter of authorization.

SUMMARY:

In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA), as amended, NMFS hereby promulgates regulations to govern the incidental taking of marine mammals by Avangrid Renewables, LLC, (Avangrid), the parent company of the original applicant, Park City Wind, LLC (Park City Wind), during the construction of the New England Wind Project (the Project), an offshore wind energy project, developed in two phases, known as Park City Wind (phase 1) and Commonwealth Wind (phase 2), in Federal and State waters off of Massachusetts, specifically within the Bureau of Ocean Energy Management (BOEM) Commercial Lease of Submerged Lands for Renewable Energy Development on the Outer Continental Shelf (OCS) Lease Areas (OCS-A 0534 and OCS-A 0561) and the southwest (SW) portion of Lease Area OCS-A 0501 (collectively referred to as the Lease Area), and along an export cable routes to sea-to-shore transition points (collectively, the Project Area), over the course of 5 years (March 27, 2025, through March 26, 2030). The proposed rule for this action concerned only Lease Areas OCS-A 0534 and the SW portion of Lease Area OCS-A 0501. However, after publication of the proposed rule, Lease Area OCS-A 0534 was segregated into two portions: OCS-A 0534 and OCS-A 0561. Phase 1 remained with Park City Wind (OCS-A 0534) while phase 2 (OCS-A 0561) was assigned to a sister company named Commonwealth Wind, LLC (subsidiary of Avangrid). As a result of this, Park City Wind requested that the Letter of Authorization (LOA), if issued, be issued to Avangrid, who would oversee the construction of the both phases of the Project by its two subsidiaries. These regulations, which allow for the issuance of a LOA for the incidental take of marine mammals during construction-related activities within the Project Area during the effective dates of the regulations, prescribe the permissible methods of taking and other means of effecting the least practicable adverse impact on marine mammal species or stocks and their habitat as well as requirements pertaining to the monitoring and reporting of such taking.

DATES:

This rule is effective from March 27, 2025, through March 26, 2030.

FOR FURTHER INFORMATION CONTACT:

Karolyn Lock, Office of Protected Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

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

Purpose and Need for Regulatory Action

This final rule, as promulgated, provides a framework under the authority of the MMPA (16 U.S.C. 1361
et seq.
) for NMFS to authorize the take of marine mammals incidental to construction of the Project within the Project Area. NMFS received a request from the applicant to incidentally take a small number of marine mammals from 39 species of marine mammals. After reviewing the request and making the required findings, NMFS could authorize the take, by harassment only, of 38 species, representing 38 stocks (19 species by Level A harassment and all 38 species by Level B harassment) incidental to the applicant's 5 years of construction activities. The applicant did not request and NMFS neither anticipates nor allows take by serious injury or mortality incidental to the specified activities in this final rulemaking.

Legal Authority for the Final 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). If such findings are made, NMFS must prescribe the permissible methods of taking, “other means of effecting the least practicable adverse impact” on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stocks for taking for certain subsistence uses (referred to as “mitigation”); and requirements pertaining to the monitoring and reporting of such takings.

As noted above, the applicant did not request and NMFS neither anticipates nor would allow take by serious injury or mortality incidental to the specified activities in this final rulemaking. Relevant definitions of MMPA statutory and regulatory terms are included below:

•
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);

•
Take
—to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362);

•
Incidental Harassment, Incidental Taking and Incidental, but not Intentional, 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);

•
Serious Injury
—any injury that will likely result in mortality (50 CFR 216.3);

•
Level A harassment
—any act of pursuit, torment, or annoyance which has the potential to injure a marine mammal or marine mammal stock in the wild (16 U.S.C. 1362; 50 CFR 216.3); and

•
Level B harassment
—any act of pursuit, torment, or annoyance which has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering (16 U.S.C. 1362).

Section 101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR part 216, subpart I, provide the legal basis for proposing and, if appropriate, issuing this rule containing 5-year regulations and associated LOA. This final rule also establishes required mitigation, monitoring, and reporting requirements for the in-water specified activities.

Summary of Major Provisions Within the Final Rule

The major provisions within this final rule include:

• Allowing NMFS to authorize, under a LOA, the take of small numbers of marine mammals by Level A harassment and/or Level B harassment (50 CFR 217.322) incidental to the Project and prohibiting take of such species or stocks in any manner not permitted (50 CFR 217.323) (
e.g.,
mortality or serious injury);

• Establishing a seasonal moratorium on impact pile driving and drilling during January 1 through April 30, annually, as well as avoiding impact pile driving and drilling in December in order to minimize impacts to North Atlantic right whales (
Eubalaena glacialis
). Impact pile driving and drilling must not be planned in December; however, it may then only occur if necessary to complete the Project within a given year and with prior approval by NMFS (
e.g.,
as a result of unforeseen circumstances such as unanticipated weather delays, unexpected technical difficulties). LOA Holder must notify NMFS in writing by September 1 of that year that pile driving or drilling cannot be avoided and circumstances are expected to necessitate pile driving or drilling in December;

• Establishing a seasonal moratorium on vibratory pile driving (
i.e.,
vibratory setting of piles) during December 1 through May 31, annually, to minimize impacts to North Atlantic right whales (
Eubalaena glacialis
);

• Establishing a seasonal moratorium on the detonation of unexploded ordnance or munitions and explosives of concern (UXO/MEC) from December 1 through May 31, annually. UXO/MEC detonation must not be planned for December or May in order to minimize impacts to North Atlantic right whales (
Eubalaena glacialis
); however, UXO/MEC detonation may occur in December or May with NMFS' approval on a case-by-case basis only.

• Requirements for UXO/MEC detonations to only occur if all other means of removal are impracticable (
i.e.,
As Low As Reasonably Practicable (ALARP) risk mitigation procedure)), conducting UXO/MEC detonations during daylight hours only, and limiting detonations to one per 24 hour period;

• Conducting both visual and passive acoustic monitoring (PAM) by trained, NMFS-approved Protected Species Observers (PSOs) and PAM operators before, during, and after select in-water construction activities;

• Establishing clearance and shutdown zones for all in-water construction activities to prevent or reduce the risk of Level A harassment and to minimize the risk of Level B harassment, including a delay or shutdown of foundation impact pile driving and delay to UXO/MEC detonation if a North Atlantic right whale is observed at any distance by PSOs or acoustically detected within certain distances;

• Establishing minimum visibility and PAM monitoring zones during foundation installation activities (
i.e.,
impact pile driving, vibratory pile driving, and drilling);

• Requiring use of at least two noise attenuation devices during all foundation installation activities and UXO/MEC detonations to reduce noise levels to those modeled assuming a broadband 10 decibel (dB) attenuation;

• Requiring sound field verification (SFV) requirements during foundation installation and UXO/MEC detonations to measure in situ noise levels for comparison against the modeled results.

• Requiring SFV during the operational phase of the Project;

• Requiring soft-start during impact pile driving and ramp-up during the use of high-resolution geophysical (HRG) marine site characterization survey equipment;

• Requiring various vessel strike avoidance measures;

• Requiring various measures during fisheries monitoring surveys, such as removing gear from the water if marine mammals are considered at-risk or are interacting with gear;

• Requiring regular and situational reporting including, but not limited to, information regarding activities occurring, marine mammal observations and acoustic detections, and sound field verification monitoring results; and

• Requiring monitoring of the North Atlantic right whale sighting networks, Channel 16, and PAM data, as well as reporting any sightings to the NMFS or sighting network.

Through adaptive management, as described in the provisions established in these regulations, NMFS Office of Protected Resources may modify (
e.g.,
delete, revise, or add to) the existing mitigation, monitoring, or reporting measures summarized above and required by the LOA.

NMFS must withdraw or suspend an LOA issued under these regulations, after notice and opportunity for public comment, if it finds the methods of taking or the mitigation, monitoring, or reporting measures are not being substantially complied with or the authorized take is having, or may have, more than a negligible impact on the concerned species or stock (16 U.S.C. 1371(a)(5)(B); 50 CFR 216.106(e)). Additionally, failure to comply with the requirements of the LOA may result in civil monetary penalties and knowing violations may result in criminal penalties (16 U.S.C. 1375; 50 CFR 216.106(g)).

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)).

The Project is listed on the Permitting Dashboard, where milestones and schedules related to the environmental review and permitting for the Project can be found at
https://www.permits.performance.gov/permitting-project/new-england-wind.

Summary of Request

On December 1, 2021, the original applicant, Park City Wind, a limited liability company registered in the State of Delaware and wholly owned subsidiary of Avangrid submitted a request for the promulgation of regulations and issuance of an associated 5-year LOA to take, by harassment only, marine mammals incidental to construction activities associated with implementation of the New England Wind Project (hereafter “Project”) offshore of Massachusetts in the BOEM Lease Area OCS-A 0534 and the possible use of the SW portion of Lease Area OCS-A 0501. The request was for the incidental, but not intentional, taking of a small number of 39 marine mammal species by Level B harassment (for all species or stocks) and by Level A harassment (for 19 species or stocks). Park City Wind did

not request, and NMFS neither expects nor would allow under this rule, take by serious injury or mortality to occur for any marine mammal species or stock incidental to the specified activities.

In response to our questions and comments, and following extensive information exchange between Park City Wind and NMFS, the applicant submitted a final revised application on July 13, 2022. NMFS deemed it adequate and complete on July 20, 2022. This final application is available on NMFS' website at
https://www.fisheries.noaa.gov/protected-resource-regulations.

On August 22, 2022, NMFS published a notice of receipt (NOR) of the adequate and complete application in the
Federal Register
(87 FR 51345), requesting public comments and information during a 30-day public comment period. During the NOR public comment period, NMFS received comment letters from one private citizen and one non-governmental organization (ALLCO Renewable Energy Limited). NMFS reviewed all submitted material and took the material into consideration during the drafting of the proposed rule.

In January 2023 and again in March 2023, Park City Wind submitted memos to NMFS detailing updates and changes to their ITA application (“Update Application”). These memos updated the density models using the 2022 Roberts
et al.
density models, project foundation installation and potential UXO/MEC detonation schedules, vibratory pile driving (
i.e.,
vibratory setting of piles) assessment, and mitigation of drilling activity. In addition, the applicant detailed development of their fisheries monitoring program and associated mitigation measures. In a May 2023 memo, Park City Wind submitted corrected take estimate amounts for foundation installation activities and total take requested across all activities. These updates were reflected in the proposed rule. These memos are available on the NMFS website at
https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llc-construction-new-england-wind-offshore-wind.

On June 8, 2023, NMFS published a proposed rule for the Project in the
Federal Register
(88 FR 37606). In the proposed rule, NMFS synthesized all of the information provided by the applicant, all best available scientific information and literature relevant to the proposed project, made preliminary small numbers and negligible impact determinations, and outlined, in detail, proposed mitigation designed to effect the least practicable adverse impacts on marine mammal species and stocks, as well as proposed monitoring and reporting measures. The public comment period on the proposed rule was open for 30 days from June 8, 2023 through July 10, 2023. A summary of public comments received during this 30-day period are described in the Comments and Responses section. The public comments are available to be viewed on the Federal e-Rulemaking Portal at
https://www.regulations.gov.

In January 2024, Park City Wind submitted a final draft of the new modeling and associated acoustic ranges, exposure estimates, and take estimates. Within these memos, the applicant revised the model(s) used and model assumptions for foundation installation activities and updated the acoustic ranges, exposure ranges, exposure estimates, take estimates, and amount of requested take as a result. The model changes are detailed in the
Modeling and Take Estimates
section in this final rule. NMFS accepted the updated modeling and has reflected the changes to the distance to thresholds, exposure estimates, and take estimates within the final rule. A description of these changes can be found below in the
Modeling and Take Estimates
section. This January 2024 Application Update is on NMFS website at
https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llc-construction-new-england-wind-offshore-wind.

On May 6, 2024, Park City Wind notified NMFS that it had requested that BOEM segregate a portion of lease area OCS-A-0534, which would then be assigned to another subsidiary of Avangrid, Commonwealth Wind, LLC, as lease area OCS-A 0561. Park City Wind requested to NMFS that the incidental take regulation (ITR) governing take of marine mammals incidental to activities associated with both phases of the Project and the associated LOA (if issued by NMFS) be issued to Park City Wind's parent company, Avangrid, a limited liability company registered in the State of Oregon, who would oversee phase 1 (constructed and operated by Park City Wind) and phase 2 (constructed and operated by Commonwealth Wind) of the New England Wind Project. The lease segregation, completed by BOEM on May 15, 2024, did not alter the geographic location or size of the area in which the project would be built, nor did the applicant request any changes to the construction schedule, planned activities, or take. In short, no substantive changes to the Project were requested. As a result, where appropriate, Avangrid, owner of Park City Wind, has henceforth been incorporated as the applicant or LOA Holder throughout this final rule.

NMFS previously issued one Incidental Harassment Authorization (IHA) to Park City Wind for the taking of small numbers of marine mammals incidental to marine site characterization surveys, using HRG of the Project's phase 1 (Park City Wind) in the BOEM Lease Area OCS-A 0534 (87 FR 44087, July 7, 2022); phase 2 was not part of this authorization (Commonwealth Wind). However, no work occurred under this initial IHA and Park City Wind requested a reissuance of the IHA with new effective dates. NMFS reissued the IHA (88 FR 88892, December 26, 2023) with the new effective dates of March 1, 2024, through February 28, 2025. NMFS has also previously issued an IHA to Avangrid, owner of Park City Wind, LLC, to take small numbers of marine mammals incidental to HRG surveys in BOEM Lease Area (OCS-A 0508) off the coasts of North Carolina and Virginia (84 FR 31032, June 28, 2019). To date, Park City Wind and Avangrid have complied with all IHA requirements (
e.g.,
mitigation, monitoring, and reporting). Applicable monitoring results may be found in the Estimated Take of Marine Mammals section. If available, the full monitoring reports can be found on NMFS' website at
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable.

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 (ITA)—the authorization holder will 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 will 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

will remain in place. The responsibility to comply with the applicable requirements of any vessel speed rule will become effective immediately upon the effective date of any final vessel speed rule and, when notice is published on the effective date, NMFS will also notify Avangrid if the measures in the speed rule were to supersede any of the measures in the MMPA authorization such that they were no longer required.

Description of the Specified Activity

Overview

Avangrid plans to construct and operate two offshore wind projects within OCS-A 0534 and OCS-A 0561: Park City Wind (phase 1, 0534) and Commonwealth Wind (phase 2, 0561) (collectively called New England Wind; hereinafter referred to as “Project”). The Project will occupy all of Lease Area OCS-A 0534, OCS-A 0561, and potentially a portion of Lease Area OCS-A 0501 in the event that Vineyard Wind 1 does not develop spare or extra positions included in Lease Area OCS-A 0501. If Vineyard Wind 1 does not develop spare or extra positions in Lease Area OCS-A 0501, those positions would be assigned to Lease Area OCS-A 0534.

The Project will consist of several different types of permanent offshore infrastructure, including wind turbine generators (WTGs) and associated foundations, electrical service platforms (ESPs) and their foundations, inter-array cables, offshore export cables, and scour protection. Specifically, activities to construct the Project include the installation of 41-62 WTGs and 1-2 ESPs in phase 1 by impact and vibratory pile driving and, in the event of an obstruction, drilling. Phase 2 depends upon the final footprint of phase 1. Phase 2 is expected to include the installation of 64-88 WTGs and 1-3 ESP positions by impact and vibratory pile driving and, in the event of an obstruction, drilling. In total, up to 129 WTGs and 2-5 ESPs may be constructed at a maximum of 130 positions (2 positions may potentially have co-located ESPs (
i.e.,
two foundations installed at one grid position), resulting in 132 foundations). Additional activities will include cable installation, site preparation activities (
e.g.,
dredging), HRG surveys, the potential detonations of up to 10 UXO/MEC, and conducting several types of fishery and ecological monitoring surveys. Multiple vessels will transit within the Project Area and between ports and the wind farm to perform the work and transport crew, supplies, and materials. All offshore cables will connect to onshore export cables, substations, and grid connections in Barnstable County, Massachusetts. Marine mammals exposed to elevated noise levels during pile driving, drilling, UXO/MEC detonations, or site characterization surveys may be taken by Level A harassment and/or Level B harassment, depending on the specified activity. A detailed description of the construction project is provided in the proposed rule as published in the
Federal Register
(88 FR 37606, June 8, 2023).

Dates and Duration

Avangrid anticipates activities resulting in harassment to marine mammals occurring throughout all 5 years of the final rule (table 1). Offshore Project activities are expected to begin in March 2025, after issuance of the 5-year LOA, and continue through March 2030. Avangrid anticipates the following construction schedule over the 5-year period. Avangrid has noted that these are the best and conservative estimates for activity durations, but that the schedule may shift due to weather, mechanical, or other related delays. Additional information on dates and activity-specific durations can be found in the proposed rule and are not repeated here.

Table 1—Activity Schedule To Construct and Operate the Project

Project activity
Expected timing
Expected duration

HRG Surveys
Q1 2025-Q4 2029
Any time of the year, up to 25 days per year.

Scour Protection Pre- or Post-Installation
Q1 2025-Q4 2029
Any time of the year.

WTG and ESP Foundation Installation, Schedule A

Q2-Q4 2026 and 2027
1

Up to 8 months per year.

WTG and ESP Foundation Installation, Schedule B

Q2-Q4 2026, 2027, and 2028
1

Up to 8 months per year.

Horizontal Directional Drilling at Cable Landfall Sites
Q4 2025-Q2 2026
Up to 150 days.

UXO/MEC Detonations
Q2-Q4 2025 and 2026
Up to 6 days in 2025 and 4 days in 2026. No more than 10 days total.

Inter-array Cable Installation
Q3-Q4 2026 and Q2 2027-Q2 2028
Phase 1: 5 months; Phase 2: 10 months.

Export Cable Installation and Termination
Q2 2026-Q2 2028
Phase 1: 8-9 months; Phase 2: 13-17 months.

Fishery Monitoring Surveys
Q1 2025-Q4 2029
Any time of year.

Turbine Operation
Initial turbines operational 2027, all turbines operational by 2028.

Note:
Project activities are anticipated to start no earlier than Q1 2025. Q1 = January through March; Q2 = April through June; Q3 = July through September; Q4 = October through December. The Project is divided into two phases: Park City Wind (phase 1) and Commonwealth Wind (phase 2).

1
Foundation installation pile driving and drilling would be limited to May 1-December 31, annually; however, impact pile driving and drilling in December will not be planned but may occur due to unforeseen circumstances (
e.g.,
unanticipated extended weather delays, unexpected technical difficulties) and with NMFS approval. Vibratory pile driving (
e.g.,
vibratory setting of piles) must not occur December 1-May 31, annually.

Specified Geographical Region

A detailed description of the Specified Geographical Region, identified as the Mid-Atlantic Bight, is provided in the proposed rule (88 FR 37606, June 8, 2023). Since the proposed rule was published, no changes have been made to the Specified Geographical Region. This final rule provides clarity on the boundaries of the Mid-Atlantic Bight, which spans from Cape Hatteras, North Carolina to Cape Cod, Massachusetts and extends into the western Atlantic to the 100-m isobath. All of Avangrid's specified activities (
i.e.,
pile driving and drilling of WTG and ESP foundations; number of possible UXO/MEC detonations (
n
=10); placement of scour protection; trenching, laying, and burial activities associated with the installation of the export cable route and inter-array cables; HRG site characterization surveys; and WTG operation) are concentrated in the Lease Area and cable corridor offshore Massachusetts. Avangrid would also concentrate vessel use within this area;

however, some limited vessel movement may occur outside this area.

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BILLING CODE 3510-22-C
Comments and Responses

NMFS published a proposed rule in the
Federal Register
on June 8, 2023 (88 FR 37606) for a 30-day public comment period. The proposed rule described, in detail, the specified activities, the specified geographical region of the specified activities, the marine mammal species that may be affected by these activities, and the anticipated effects on marine mammals. In the proposed rule, we requested that interested persons submit relevant information, suggestions, and comments on Park City Wind's (now Avangrid's) request for the promulgation of regulations and issuance of an associated LOA described therein, our estimated take analyses, the

preliminary determinations, and the proposed regulations.

NMFS received 41 comment submissions, including comments from the Marine Mammal Commission (Commission), several non-governmental organizations, and private citizens, all of which are available for review on
https://www.regulations.gov.
Some of these comments were out-of-scope or not applicable to the Project (
e.g.,
general opposition to or support of offshore wind projects, concerns for other species outside NMFS' jurisdiction) and are not described herein or discussed further. Non-governmental organizations included: Long Island Commercial Fishing Association, Responsible Offshore Development Alliance, and Green Oceans. These letters, and the Commission's, contained substantive information that NMFS considered in this final rule, including comments related to the estimated take analysis, final determinations, and final mitigation, monitoring, and reporting requirements. A summary of comments are described below, along with NMFS' responses.

Modeling and Take Estimates

Comment 1:
The Commission has stated that, due to uncertainty in how NMFS will be addressing their previously submitted comments for other final offshore wind rulemakings, they are not providing “an exhaustive letter regarding similar issues” for the proposed action. They have stated that, in lieu of this, they incorporate by reference all previously submitted comment letters for past proposed rules (
i.e.,
Empire Wind, Dominion Energy Virginia, Sunrise Wind, Revolution Wind, Ocean Wind 1, South Fork Wind) and that NMFS should specifically review these previously submitted letters (
e.g.,
Sunrise Wind (88 FR 8996, February 10, 2023), Revolution Wind (87 FR 79072, December 23, 2022), and Ocean Wind 1 (87 FR 64868, October 26, 2022) and incorporate, where applicable, relevant information in the context of the Project. They specifically noted that these general concerns could include “underestimated numbers of Level A and B harassment takes (including failing to round up to group size), incomplete SFV measurement requirements, insufficient mitigation and monitoring measures, errors and omissions in the preamble to and the proposed rule, and the general issue of quality control and quality assurance in NMFS's preparation of proposed incidental take authorizations.”

Response:
NMFS acknowledges the receipt of a comment letter on the proposed Project by the Commission, as well as receipt of comment letters from the Commission for the other referenced proposed projects. We appreciate that, in the past, the Commission has provided very specific and detailed comments and suggestions on NMFS' actions, as a collaborative effort to improve both the ITAs themselves as well as the conservation benefits for NMFS' trust species. Because the Commission did not provide specific comments on the proposed rule for the Project, we cannot address any specific concerns. However, we can address general themes of concern raised in previous letters, and, inasmuch as another specific comment is applicable here, we refer the Commission back to our previous responses.

Overall, the Commission's letters raised concerns over concern underestimated Level A and B harassment zones and numbers of takes, incomplete SFV measurement requirements, insufficient mitigation and monitoring measures, errors and omissions in the proposed rule and its preamble, and the general issue of quality control and quality assurance in NMFS's preparation of proposed ITAs. With respect to mitigation, monitoring and reporting requirements, we have thoroughly addressed the Commission's previous concerns and have updated final rules, including this one, accordingly. Lastly, any “omissions” and “general issues of quality control and quality assurance” from one action are less likely to be present in another action as updates are carried through across actions (although NMFS does not agree that every example previously raised by the Commission was, in fact, an error).

Comment 2:
Commenters recommend NMFS re-estimate and authorize Level A harassment takes based on modeling results for the worst-case scenario rather than presuming an arbitrary 80- or 100-percent reduction for mitigation efficacy and/or a 10-dB sound attenuation for impact pile driving, re-estimate and authorize Level B harassment takes based on more conservative assumptions for the pile-driving scenarios that could occur (including only one monopile or fewer than four pin piles installed per day), re-estimate the various mortality, Level A harassment, and Level B harassment zones and numbers of takes based on 0 dB of sound attenuation for UXO/MEC detonations and authorize Level A and B harassment takes, including behavior takes, that could result from UXO/MEC detonations, and increase any Level A or B harassment takes to mean group size (including updates that reflect the results of more recent marine mammal surveys in the Rhode Island-Massachusetts WEA). Other commenters had similar comments. Commenter(s) also suggested that the numbers of takes, particularly with respect to the North Atlantic right whale, rely on mitigation methods that remain unproven.

Response:
NMFS disagrees that our analysis should carry forward take estimates based on the worst-case scenario that assumes no reduction of impacts results from the mitigation and notes that the commenter did not present any data supporting their recommendation. As described in the proposed rule, this final rule reasonably assumes that the mitigation efforts will be effective at reducing the potential for Level A harassment calculated in the density-based models. The models do not account for mitigation (except with respect to assuming attenuation and seasonal restrictions) and, therefore, it is reasonable to assume the model overestimates Level A harassment. Further, while the scientific literature documents marine mammals are likely to avoid loud noises such as pile driving (
e.g.,
Brandt
et al.,
2016, Nowack
et al.,
2004), avoidance was not quantitatively considered in the take estimates (although NMFS reasonably predicts this natural behavior will further reduce the potential for Level A harassment).

In the proposed rule, NMFS described the best available science, which supports the assumption that at least 10 dB of attenuation can be reliably achieved using noise attenuation systems such as a double bubble curtain. The commenter did not provide reason for why they believe this was an overestimate nor did they suggest an alternative amount of attenuation NMFS should consider other than zero attenuation. Other commenters expressed similar support stating that bubble curtains are not effective for low-frequency cetaceans. NMFS agrees that attenuation levels vary by frequency band and that bubble curtains attenuate higher frequency sounds more effectively; however, NMFS disagrees that lower frequency bands, which are important to consider when evaluating impacts, are not attenuated at all. The data from Bellmann (2021), shows that for both single and double bubble curtains, more than 10 dB of attenuation was achieved for bands as low as 32 Hz. And while it is true that performance diminishes significantly at lower frequencies (<32 Hz), those bands also contain significantly less pile driving sound and is 16+ dB outside the most susceptible frequency range for low-frequency cetaceans.

NMFS recognizes that the key to effective mitigation is the ability to detect marine mammals to trigger such mitigation. Avangrid is required to undertake extensive monitoring to maximize marine mammal detection effectiveness. The reduction to the density-based take estimate appropriately reflects and acknowledges the monitoring efforts, including the placement of three PSOs on the pile driving platform and dedicated PSOs vessel(s) and PAM.

NMFS agrees that there is potential for behavioral disturbance from a single detonation per day and disagrees that “behavior takes” were omitted and have not been accounted for. However, the behavioral threshold for underwater detonations identified by the Commission (5 dB less than the temporary threshold shift (TTS) is only applicable to multiple detonations per day. NMFS is not aware of evidence to support the assertion that animals will have behavioral responses that would qualify as take to temporally and spatially isolated explosions at received levels below the TTS threshold. Accordingly, the current take estimate framework allows for the consideration of behavioral disturbance resulting from single explosions specifically if they are exposed above the TTS threshold, as opposed to the 5-dB lower threshold for behavioral disturbance from multiple detonations. We acknowledge in our analysis that individuals exposed above the TTS threshold may also be harassed by direct behavioral, disruption and those potential impacts are considered in the negligible impact determination. The distances to harassment thresholds have not changed from the application and proposed rule and are presented in this final rule. Take estimates did not change as a result of including this additional information.

Comment 3:
Commenter(s) claimed that NMFS thresholds are outdated, primarily because scientific literature demonstrates examples where behavioral disturbances have been documented where received levels are lower than 160 dB. Moreover, the commenter suggested that estimating the extent of Level B take from impact driving using the 160dB (impulsive) threshold is flawed because an animal may be exposed to several hours of pile driving per day which should be considered continuous and that, although impulsive at the source, the sound from impact driving may be received as a continuous source at a distance. Commenter(s) stated that vessel noise is not included in the effects and that it should be included in calculations for harassment zones (as a continuous noise source) and as a source of take. For these reasons, commenter(s) suggested the proposed rule underestimates the takes by Level B harassment and “zones of impact”; thus NMFS' small numbers and negligible impact determination is flawed.

Response:
For the reasons described below, NMFS disagrees that the 160-dB threshold for behavioral harassment is not supported by the best available science and that the small numbers and negligible impact determinations are flawed based on the use of this threshold in the take estimate analysis. The potential for behavioral response to an anthropogenic source can be highly variable and context-specific (Ellison
et al.,
2012). While NMFS acknowledges the potential for Level B harassment at exposures to received levels below 160 dB rms, it should also be acknowledged that not every animal exposed to received levels above 160 dB rms will respond in ways constituting behavioral harassment. There are a variety of studies indicating that contextual variables play a very important role in response to anthropogenic noise, and the severity of effects are not necessarily linear when compared to a received level (RL). Several studies (
e.g.,
Nowacek
et al.,
2004 and Kastelein
et al.,
2012 and 2015) showed there were behavioral responses to sources below the 160 dB threshold but also acknowledged the importance of context in these responses. For example, Nowacek
et al.
(2004) reported the behavior of five out of six North Atlantic right whales was disrupted at RLs of only 133-148 dB re 1 μPa (returning to normal behavior within minutes) when exposed to an alert signal. However, the authors also reported that none of the whales responded to noise from transiting vessels or playbacks of ship noise even though the RLs were at least as loud and contained similar frequencies to those of the alert signal. The authors state that a possible explanation for whales responding to the alert signal and not responding to vessel noise is due to the whales having been habituated to vessel noise while the alert signal was a novel sound. In addition, the authors noted differences between the characteristics of the vessel noise and alert signal, which may also have played a part in the differences in responses to the two noise types. Therefore, it was concluded that the signal itself, as opposed to the RL, was responsible for the response. DeRuiter
et al.
(2012) also indicate that variability of responses to acoustic stimuli depends not only on the species receiving the sound and the sound source, but also on the social, behavioral, or environmental contexts of exposure. Finally, behavioral responses depend on many contextual factors, including range to source, RL above background noise, novelty of the signal, and differences in behavioral state (Ellison
et al.,
2012, Gong
et al.,
2014). Similarly, Kastelein
et al.
(2015) examined behavioral responses of a harbor porpoise to sonar signals in a quiet pool but stated behavioral responses of harbor porpoises at sea would vary with context such as social situation, sound propagation, and background noise levels.

NMFS uses 160 dB (rms) as the received sound pressure level for estimating the onset of Level B behavioral harassment takes for impulsive/intermittent sound sources, and this is currently considered the best available science while acknowledging that the 160 dB
rms
step-function approach is a simplistic approach. While it may be true because of reverberation that impulsive pile driving strikes may “stretch” as their sound travels through the environment, we do not classify these sounds as continuous, like drilling and vibratory pile driving. NMFS' behavioral harassment thresholds consider instantaneous exposure to noise and are based on a received level. These thresholds do not account for duration of exposure, as our PTS onset thresholds do. Thus, whether an individual was exposed to a few pile driving strikes or exposed for several hours of pile driving, the 160-dB threshold would still apply. While it is correct that in practice it works as a step-function (
i.e.,
animals exposed to received levels above the threshold are considered to be “taken” and those exposed to levels below the threshold are not), it is in fact intended as a sort of mid-point of likely behavioral responses, which are extremely complex depending on many factors including species, noise source, individual experience, and behavioral context. What this means is that, conceptually, the function recognizes that some animals exposed to levels below the threshold will in fact react in ways that appropriately considered take while others that are exposed to levels above the threshold will not. Use of the 160-dB threshold allows for a simplistic quantitative estimate of take while we can qualitatively address the variation in responses across different received levels in our discussion and analysis.

Overall, we reiterate the lack of scientific consensus regarding what criteria might be more appropriate. Defining sound levels that disrupt behavioral patterns is difficult because

responses depend on the context in which the animal receives the sound, including an animal's behavioral mode when it hears sounds (
e.g.,
feeding, resting, or migrating), prior experience, and biological factors (
e.g.,
age and sex). Other contextual factors, such as signal characteristics, distance from the source, and signal to noise ratio, may also help determine response to a given received level of sound. Therefore, levels at which responses occur are not necessarily consistent and can be difficult to predict (Southall
et al.,
2007; Ellison
et al.,
2012; Southall
et al.,
2021). For example, Gomez
et al.
(2016) reported that RL was not an appropriate indicator of behavioral response. Further, the seminal reviews presented by Southall
et al.
(2007), Gomez
et al.
(2016), and Southall
et al.
(2021) did not suggest any specific new criteria due to lack of convergence in the data. Undertaking a process to derive defensible exposure-response relationships, as suggested by Tyack and Thomas (2019), is complex. The recent systematic review by Gomez
et al.
(2016) was unable to derive criteria expressing these types of exposure-response relationships based on currently available data.

NMFS acknowledges that there may be methods of assessing likely behavioral responses to acoustic stimuli that better capture the variation and context-dependency of those responses than the simple 160 dB step-function used here; there is no agreement on what that method should be or how more complicated methods may be implemented by applicants. NMFS is committed to continuing its work in developing updated guidance with regard to acoustic thresholds but pending additional consideration and process, is reliant upon an established threshold that is reasonably reflective of best available science.

NMFS disagrees that vessel noise would result in take and, therefore, be necessary to include in the take calculations in this final rule. Vessels produce low-frequency noise, primarily through propeller cavitation, with main energy in the 5-300 hertz (Hz) frequency range. Source levels range from about 140 to 195 decibels (dB) referenced to 1 (re 1) μPa (micropascal) at 1 m (National Research Council (NRC), 2003; Hildebrand, 2009), depending on factors such as vessel type, load, and speed, and vessel hull and propeller design. Studies of vessel noise show that it appears to increase background noise levels in the 71-224 Hz range by 10-13 dB (Hatch
et al.,
2012; McKenna
et al.,
2012; Rolland
et al.,
2012). As discussed in the Negligible Impact Analysis and Determination section (specifically the
Auditory Masking or Communication Impairment
section) of both the proposed and final rule, the level of masking that could occur from the specified activities will have a negligible impact on marine mammals, including North Atlantic right whales. 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 sound source are in close enough proximity for the effect to occur. In addition, this time period would need to coincide with a time that the animal was utilizing sounds at the masked frequency). As our analysis (both quantitative and qualitative components) indicates, because of the relative movement of whales and vessels, as well as the stationary nature of a majority of the activities, we do not expect these exposures with the potential for masking to be of a long duration within a given day. Further, because of the relatively low density of North Atlantic right whales during months when most of project activities would be occurring (
i.e.,
May through November in most cases), and the relatively large area over which the vessels will travel and where the activities will occur, we do not expect any individual North Atlantic right whales to be exposed to potentially masking levels from these surveys for more than a few days in a year. Furthermore, as many of the activities are occurring in clusters and specific areas rather than sporadically dispersed in the Project Area (
i.e.,
foundation installation all occurs in the same general area, nearshore cable installation activities occur in relatively similar and nearby areas), animals are likely to temporarily avoid these locations during periods where activities are occurring but are expected to return once activities have ceased.

As noted above, any masking effects of the project's activities are expected to be limited in duration, if present. For HRG surveys, given the likelihood of significantly reduced received levels beyond short distances from the transiting survey vessel, the short duration of potential exposure, the lower likelihood of extensive additional contributors to background noise offshore and within these short exposure periods, and the fact that the frequency of HRG signals are primarily above those used in social communication or for detection of other important clues, we believe that the incremental addition of the survey vessel is unlikely to result in more than minor and short-term masking effects. For pile driving and drilling, and especially foundation installation, masking effects are more likely given the larger zones and longer durations, and animals that approach the source could experience temporary masking of some lower frequency cues. However, any such effects would be localized to the areas around these stationary activities, which means that whales transiting through the area could adjust their transit away from the construction location and return once the activity has completed. As described in the “Potential Effects of the Activities on Marine Mammals” section of the proposed rule, NMFS acknowledges the noise contributions of vessels to the soundscape and the potential for larger vessels such as commercial shipping vessels, especially, to mask mysticete communication. For the activity as a whole, including the operation of supporting vessels for Avangrid's activities, any masking that might potentially occur would likely be incurred by the same animals predicted to be exposed above the behavioral harassment threshold, and thereby accounted for in the analysis. NMFS notes that the commenter did not provide additional scientific information for NMFS to consider to support its concern.

Comment 4:
Commenter(s) recommended that NMFS should consider the best available data regarding North Atlantic right whale abundance in the project area, as well as the most comprehensive models for estimating marine mammal take and developing robust mitigation measures.

Response:
The MMPA and its implementing regulations require that ITRs be established based on the best scientific evidence available. NMFS generally considers the information in the most recent U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments Report (SAR; Hayes
et al.,
2023) to be the best scientific evidence available for a particular marine mammal stock because of the MMPA's rigorous SAR procedural requirements, which includes peer review by a statutorily established Scientific Review Group. Since publication of the proposed rule, NMFS has released the draft 2023 Stock Assessment Report indicating the North Atlantic right whale population abundance is estimated as 340 individuals based on sighting data through December 31, 2021 (89 FR 5495, January 29, 2024). NMFS has used the best scientific evidence available in the analysis of this final rule. This new stock abundance estimate, which is based on the analysis from Pace
et al.
(2017) and subsequent

refinements found in Pace (2021), provides the best scientific evidence available, and in this case, the most recent estimate, including improvements to NMFS's right whale abundance model. NMFS notes this estimate aligns with the 2022 North Atlantic Right Whale Report Card (Pettis
et al.,
2022) estimate (also 340) based on sighting data through August 2022 but, as described above, the SARs are peer reviewed by other scientific review groups prior to being finalized and published and the Report Card is published independently by Consortium members without undertaking this peer review process. Based on this, NMFS has considered all relevant information regarding North Atlantic right whale, including the information cited by the commenters. However, NMFS has relied on the draft 2023 SAR in this final rule as it reflects the best scientific evidence available.

We further note that this change in abundance estimate does not change the estimated take of North Atlantic right whales or authorized take numbers, nor affect our ability to make the required findings under the MMPA for Avangrid's construction activities.

NMFS evaluates the models used by applicants to support take estimates to ensure that they are methodologically sound and incorporate the best science available. NMFS also requires use of the Roberts
et al.
(2016, 2023) density data and SARs abundance estimates for all species, both of which represent the best scientific evidence available regarding marine mammal occurrence.

Comment 5:
Commenter(s) stated that Level A harassment in the form of a Permanent Threshold Shift (PTS) would result in deafness and lead to mortality. It was also asserted that Level B harassment in the form of a TTS is temporary deafness which could result in an increased risk of vessel strike. Lastly, that NMFS has refused to acknowledge the lack of available data on low frequency cetacean hearing or potential behavioral impacts from noise on low frequency cetacean species.

Response:
Neither the proposed rule or this final rule allow mortality or serious injury of marine mammals to be authorized. The best scientific evidence available indicates that the anticipated impacts from the specified activities potentially include avoidance, cessation of foraging or communication, TTS and PTS, stress, masking,
etc.
(as described in the Effects of the Specified Activities on Marine Mammals and their Habitat section in the proposed rule). NMFS defines a threshold shift 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 (PTS), in which case there is an irreversible increase in the threshold of audibility at a specified frequency or portion of an individual's hearing range or temporary, 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). 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 or deafness as it is a temporary form of hearing impairment. Repeated sound exposure that leads to TTS could cause PTS. For this project, as stated in the proposed rule, 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 or instantaneous UXO/MEC detonation (
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 either impact pile driving or UXO/MEC detonation, 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.

As stated in the proposed rule, NMFS acknowledges that there is limited data on threshold shifts in marine mammals. Relationships between TTS and PTS thresholds have not been studied in marine mammals, and there is no PTS data for cetaceans. However, such relationships are assumed to be similar to those in humans and other terrestrial mammals. Noise exposure can result in either a permanent shift in hearing thresholds from baseline (PTS; a 40 dB threshold shift approximates a PTS onset;
e.g.,
Kryter
et al.,
1966; Miller, 1974; Henderson
et al.,
2008) or a temporary, recoverable shift in hearing that returns to baseline (a 6 dB threshold shift approximates a TTS onset;
e.g.,
Southall
et al.,
2019). Based on data from terrestrial mammals, a precautionary assumption is that the PTS thresholds, expressed in the unweighted peak sound pressure level metric (PK), for impulsive sounds (such as impact pile driving pulses) are at least 6 dB higher than the TTS thresholds and the weighted PTS cumulative sound exposure level thresholds are 15 (impulsive sound) to 20 (non-impulsive sounds) dB higher than TTS cumulative sound exposure level thresholds (Southall
et al.,
2019a). Given the higher level of sound or longer exposure duration necessary to cause PTS as compared with TTS, PTS is less likely to occur as a result of these activities, but it is possible and a small amount has been proposed for authorization for several species. For more detailed information on PTS and TTS, please see the Hearing Threshold Shift and Negligible Impact Determination sections of the proposed rule.

NMFS disagrees that the potential effects to species as a result of the project's specified activities would result in increased risk of vessel strikes. Please see our response to
Comment 8
for more details on the vessel strike avoidance requirements required by this final rule.

Comment 6:
A commenter suggested that NMFS' low-frequency cetacean weighting function is inaccurate because it applies a 2-pole High-pass filter set at 200 Hz, while Southall
et al.
(2007) suggested moving the high-pass filter down to 7Hz. The commenter was also concerned that applying any weighting function underestimates the potential impacts on marine mammals because they claim applying a weighting function assumes that when hearing is less sensitive at the outer limits of the hearing range, the effects to the animal (potential for adverse impact) will be insignificant or non-existent unless inordinately loud. They also claimed that there is no empirical evidence that NMFS' weighting curve aligns with mysticetes infrasonic hearing. Further, they assert signal kurtosis was not accounted for in NMFS analysis and should be included in any predictive impact models. Commenter(s) also state that the spreading model is inadequate for modeling noise levels as it does not account for reflection off the water's surface or from other sources.

Response:
The marine mammal weighting functions in NMFS' 2018 Revised Technical Guidance do not contain any filters. Furthermore, the Revised Technical Guidance provides generalized hearing ranges for marine mammal species, where the low-frequency cetacean lower bounds of the hearing range start at 7 kHz. These weighting functions are meant to reflect the hearing groups' susceptibility to noise-induced hearing loss and are based on audiogram data, as well as TTS data. Furthermore, for impulsive sources, there are peak sound pressure level criteria that are unweighted. Thus, impacts of noise on hearing will not be underestimated. For low-frequency cetaceans, since direct measurements of hearing ability are lacking, weighting functions are based on a multitude of information, including anatomical studies and modeling (Houser
et al.,
2001; Parks
et al.,
2007; Tubelli
et al.,
2012; Cranford and Krysl 2015); vocalizations (see reviews in Richardson
et al.,
1995; Wartzok and Ketten, 1999; Au and Hastings, 2008); taxonomy; and behavioral responses to sound (Dahlheim and Ljungblad, 1990; see review in Reichmuth, 2007). Finally, kurtosis is an additional metric to determine if a sound is impulsive versus non-impulsive (
i.e.,
kurtosis is a measure of the “peakedness” of a noise waveform, with the impulsive components (Qiu
et al.,
2020). As described in the proposed rule and NMFS' Technical Guidance (NMFS, 2018), NMFS applies different thresholds in an impact analysis for impulsive and non-impulsive sources. Impact pile driving is categorized as an impulsive sound. Thus, while kurtosis was not assessed directly, whether a sound is impulsive or non-impulsive is inherently considered in our analyses when assessing the potential for PTS (
i.e.,
deciding which acoustic thresholds are appropriate based on sound source characteristics that include a source's impulsiveness). Therefore, kurtosis (the impulsivity of a sound source) is accounted for in NMFS analysis.

Potential impacts to marine mammal nervous systems through exposure to sound were discussed in the proposed rule in the Potential Effects of Underwater Sound on Marine Mammals section. NMFS assumes that the reference to “injury-causing” SPL by the commenter is the potential for a permanent threshold shift (PTS).

NMFS disagrees that the spreading model is inadequate. The degree to which underwater sound propagates away from a sound source is dependent on a variety of factors, which notably includes the frequency and directivity of the source, water depth (or bathymetry), the reflective or absorptive nature of the seabed, and other factors. Spherical spreading occurs in a perfectly unobstructed (free-field) environment not limited by depth or water surface, resulting in a 6-dB reduction in sound level for each doubling of distance from the source (20 × log[range]). Spherical spreading can be thought of as a `direct path' model, as all sound in the water column is assumed to have arrived via a direct path from the source. Cylindrical spreading occurs in an environment in which sound propagation is bounded by the water surface and sea bottom, resulting in a reduction of 3 dB in sound level for each doubling of distance from the source (10 × log[range]). Both cylindrical spreading and the often used `practical spreading' model are multi-path models, in that they account for sound which may consist of both direct paths and paths consisting of reflections from the seabed and the sea surface.

As described in the proposed rule, the area of water ensonified at or above the RMS 160-dB threshold was calculated using a simple model of sound propagation loss, which accounts for the loss of sound energy over increasing range. Our use of the spherical spreading model, is a reasonable approximation over the relatively short ranges involved. Even in conditions where cylindrical spreading (where propagation loss = 10 × log [range]; such that there would be a 3-dB reduction in sound level for each doubling of distance from the source) may be appropriate (
e.g.,
non-homogenous conditions where sound may be trapped between the surface and bottom), this effect does not begin at the source. Rather, spreading is typically more or less spherical from the source out to some distance, and then may transition to cylindrical (Richardson
et al.,
1995). Further, for these types of surveys, NMFS has determined that spherical spreading is a reasonable assumption even in relatively shallow waters, as the reflected energy from the seafloor will be much weaker than the more dominant, direct path energy. This is a result of the typically high-frequency and often downward directed nature of most HRG sources. Similar arguments, related to the validity of spherical spreading in shallow water for some HRG sources, have been made in literature (Ruppel
et al.,
2022), and NMFS has relied on this approach for past ITAs with similar equipment, locations, and depths. NMFS' User Spreadsheet tool assumes a “safe distance” methodology for mobile sources where propagation loss is spherical spreading (20LogR) (
https://media.fisheries.noaa.gov/2020-12/User_Manual%20_DEC_2020_508.pdf?null
), and NMFS calculator tool for estimating isopleths to Level B harassment thresholds also incorporates the use of spherical spreading. NMFS has determined that spherical spreading is the most appropriate form of propagation loss for these surveys and represents the best scientific information available.

Comment 7:
Commenter(s) stated that auditory injury can occur below the PTS threshold and could occur below the TTS threshold. Further, that noise levels that did not manifest in PTS soon after an exposure event could cause irreversible neural damage in mammals after repeated or cumulative exposure. They also stated that the threshold for tissue injury has been found to occur at lower threshold than the threshold for TTS onset (Houser, 2021). NMFS' nearly singular focus on PTS distance (distance from activity at which partial or full permanent deafness will be induced in the whale) as the only indicator of “take” (premature death or reproductive failure affecting the population) is not reasonable. NMFS has no empirically derived direct measure of thresholds for PTS harm, but rather PTS is modeled from (limited) TTS data. NMFS is inappropriately defining “harm” to low-Frequency baleen whales as NMFS does not have any empirically-determined benchmark for what is the injury-causing sound pressure level (SPL) against which to measure the proposed activities.

Response:
NMFS's TTS thresholds represent an onset of noise-induced hearing loss (
i.e.,
6 dB threshold shift) and are 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). There have been no indications that in marine mammals TTS occurs below our current thresholds. Furthermore, as Houser 2021 indicates “There are relatively few studies demonstrating that TTS can be associated with the destruction of tissue. To date, relevant studies have only been performed in terrestrial laboratory animals.” Studies on terrestrial mammals indicating neuropathy from noise exposure are associated with threshold shifts of 40 to 50 dB. Finally, PTS is defined as a threshold shift that does not fully recover back to baseline levels. It should not be assumed that an animal with PTS is deaf.

As stated in the proposed rule and reiterated here, there are no PTS data available for 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 frequency range affected 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. More information on PTS and TTS-PTS shift can be found in the “Negligible Impact Analysis and Determination” and the “Potential Effects of Underwater Sound on Marine Mammals” sections in the proposed rule. Furthermore, NMFS also relies on our behavioral harassment thresholds to assess potential effects occurring below levels associated with PTS and TTS. For information on the 160 dB threshold (onset of Level B behavioral harassment), please see our response to
Comment 3.
For more information related to PTS, please see our response to
Comment 5.

Mitigation

Comment 8:
Commenter(s) requested NMFS add to or modify the vessel strike avoidance mitigation measures contained within the proposed rule. Recommendations included “strengthening vessel speed restrictions”, and if weather or other conditions limit the range of observation, shutdown zones (including for transiting vessels) will be initiated keeping 500 meters (m) away from North Atlantic right whale. A commenter also incorrectly claimed that vessel speed restrictions are not fully mandated or enforced for offshore wind vessels.

Response:
NMFS acknowledges that vessel strikes pose a risk to all large whales, including North Atlantic right whales and the proposed rule and this final rule require multiple mitigation measures to effect the least practicable adverse impact from vessels on marine mammals. These measures are more restrictive than other industrial, commercial, military, and recreational vessels. All transiting vessels (regardless of speed or size) are required to have a dedicated visual observer watching for marine mammals. In the event a marine mammal is observed under certain circumstances, the vessel must slow to 10 kn or less or, if within separation zones (which are encoded in regulation (62 FR 6729, March 17, 1997) or follow marine mammal viewing guidelines), turn away from and slow engines to neutral. In any SMA, DMA, Slow Zone (the latter two of which are currently voluntary for other vessels), Avangrid must operate vessels at 10 kn or less. Further, between November 1 and April 30, all vessels, regardless of size, in the specified geographical region must operate at 10 kn or less (11.5 mph). NMFS has determined it is impracticable for all vessels to travel 10 kn or less at all times and is not necessary to achieve the least practicable adverse impact given the mitigation discussed above. As described above, in many cases, there are no alternatives to the 10 kn or less speed restriction. However, NMFS has determined that when whales are less likely to be in the area and visual and acoustic monitoring is conducted, Avangrid vessels could travel at over 10 kn. NMFS has determined that the monitoring required, including both direct marine mammal monitoring and situational awareness monitoring and reporting, are sufficient to allow Avangrid vessels to travel at speeds greater than 10 kn when vessel strike risk is lowest when not subjected to the previously described restrictions.

In this final rule, NMFS is requiring that all vessels associated with Avangrid's activities must be equipped with a properly installed, operational Automatic Identification System (AIS) device and Avangrid must report all Maritime Mobile Service Identify (MMSI) numbers to NMFS Office of Protected Resources, thus facilitating monitoring of vessel speeds. In addition, NMFS maintains an Enforcement Hotline for members of the public to report violations of vessel speed restrictions. NMFS is not requiring PSOs to be onboard every transiting vessel as it is impracticable due to potential limited space on the vessels. However, as described in the proposed rule and carried forward in this final rule, Avangrid must have dedicated visual observers onboard all vessels with no other concurrent duties. The dedicated visual observer may be a PSO or a trained crew member.

Avangrid provided information pertaining to the types and number of vessels necessary to construct the project. They are also required to submit a Marine Mammal Vessel Strike Avoidance Plan, which must include, but is not limited to, more detail on ports used and means by which they would abide by the extensive measures outlined here. While NMFS acknowledges that vessel strikes can result in injury or mortality, we have analyzed the potential for vessel strike resulting from Avangrid's activity and, in consideration of the required mitigation measures specific to vessel strike avoidance included in the final rule NMFS has determined that the potential for vessel strike is so low as to be discountable and thus, no vessel strikes are expected or authorized to occur. These measures also ensure the least practicable adverse impact on species or stocks and their habitat.

Comment 9:
Commenter(s) asserted an independent review of mitigation measures should be required due to limitations associated with visual monitoring and PAM.

Response:
The MMPA does not require an independent review of mitigation measures. In contrast, it does require notice and opportunity for public comment (16 U.S.C. 1371(a)(5)(A)(i)). The public comment period is a means by which the public (
i.e.,
independent reviewers) are able to provide NMFS with mitigation measure recommendations supported by scientific evidence that NMFS takes into consideration when finalizing the rulemaking.

Comment 10:
Commenter(s) recommended clarification should be included in the LOA that explicitly states if a shutdown would be initiated as a result of weather or other conditions that limit the range of observation.

Response:
The comment refers to a 500-m shutdown zone for North Atlantic right whales; therefore, NMFS assumes the recommendation is referring to HRG surveys, a low impact activity. As described in the proposed rule and this final rule, PSOs are required to monitor the shutdown zone during operations. During periods of low visibility, alternative monitoring technology (
i.e.,
infrared or thermal cameras) must be used to monitor these zones. This final rule clarifies that when the shutdown zones become obscured for brief periods (no more than 30 minutes) due to inclement weather, survey operations may continue (
i.e.,
no shutdown is required) so long as no marine mammals have been detected. Further, the shutdown requirement is waived for certain genera of small delphids. As noted above, take of marine mammals from HRG surveys is limited overall, take by Level B harassment only is expected to occur only within a small area in close proximity to the vessel, and no Level A harassment is expected to result from exposure to the surveys even in the

absence of mitigation. There is a low likelihood that short periods of obscured visibility might potentially coincide with a marine mammal entering the shutdown zone, and a shutdown not occurring. While such an event may result in a higher level exposure than would occur if the shutdown happened, such an exposure would still not be expected to result in a Level A take and would be brief and not change the number of takes or our evaluation of their likely effects, which again, are expected to be comparatively minor. Additionally, the frequent delay and/or cessation of HRG surveys creates operational challenges and impracticalities for applicants. Altogether, the required measures affect the least practicable adverse impact on the affected species.

Comment 11:
Commenter(s) recommended that NMFS require mitigation measures that meet the least practicable adverse impact standard (
e.g.,
impacts of underwater noise be minimized to the fullest extent feasible) coupled with a robust monitoring and reporting program to ensure compliance.

Response:
As described in both the proposed rule and this final rule, NMFS has included requirements for mitigation measures that effect the least practicable adverse impact on marine mammal species or stocks and their habitat, as required under the MMPA (16 U.S.C. 1371(a)(5)(A)(i)(II). As they relate to underwater noise, the mitigation measures include sound attenuation methods that successfully (evidenced by required sound field verification measurements) reduce real-world noise levels produced by impact pile driving, vibratory pile driving, and drilling of foundation installation to, at a minimum, the levels modeled assuming 10 dB of attenuation. NMFS clarifies that, because no unattenuated piles may be driven, there is no way to confirm a 10-dB reduction; rather, in situ SFV measurements will be conducted to ensure that sound levels are at or below those modeled assuming a 10-dB reduction. In addition to the SFV requirements in the proposed rule, consistent with the Biological Opinion (BiOp), we added to this final rule the requirement that Avangrid must conduct “Abbreviated SFV” monitoring (consisting of a single acoustic recorder placed at an appropriate distance from the pile) on all foundation installations for which the complete SFV monitoring (
i.e.,
“Thorough SFV”), as required in the proposed rule, is not carried out. NMFS is requiring that these SFV results must be included in the weekly reports. Any indications that distances to the Level A harassment and Level B harassment thresholds for whales are exceeded must be addressed by Avangrid, including an explanation of factors that contributed to the exceedance and corrective actions that were taken to avoid exceedance on subsequent piles.

NMFS has required numerous monitoring and reporting requirements which result in a robust compliance program.

Effects Assessment

Comment 12:
Several commenters disagreed with NMFS' negligible impact determination, particularly for North Atlantic right whale. These comments included assertions that NMFS did not consider the imperiled population status of North Atlantic right whale; NMFS did not evaluate the cumulative effects of all projects (such as offshore wind construction and operational noise, underwater noise, and site characterization surveys and baseline background levels of ambient noise which result in stress); NMFS did not meaningfully examine the effects of the loss of communication space on marine mammals and, further, seems to misapprehend the spatial and temporal scope of the effects (
e.g.,
masking, disruption to courtship and mating behaviors, foraging/feeding, and TTS,
etc.
); that NMFS did not adequately assess the impact of behavioral disruption on feeding and similar behaviors resulting in decreased body condition nor the asserted increased risk of mortality from TTS; that any effect to the small number of breeding females can adversely affect fecundity and imperil the species; that NMFS has not used the best available science when reaching its NID by using the 160-dB threshold; and that NMFS did not consider whether abandonment of habitat that was designated with the express purpose of preventing vessel strikes would push the species further into a vessel traffic corridor, thereby elevating the risk to the species nor evaluated all the risks to North Atlantic right whale by habitat displacements as sublethal take has can a measurable effect due to the small population.

Response:
NMFS is required to authorize the requested incidental take if it finds the total incidental take of small numbers of marine mammals by U.S. citizens “while engaging in that (specified) activity” within a specified geographical region during the 5-year period (or less) will have a negligible impact on such species or stock and, where applicable, will not have an unmitigable adverse impact on the availability of such species or stock for subsistence uses (16 U.S.C. 1371(a)(5)(A)). Negligible impact is defined 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 effect on annual rates of recruitment or survival” (50 CFR 216.103). Consistent with the preamble of NMFS' implementing regulations (54 FR 40338, September 29, 1989), the impacts from other past and ongoing anthropogenic activities are factored into the baseline, which is used in the negligible impact analysis. Here, NMFS has factored into its negligible impact analysis the impacts of other past and ongoing anthropogenic activities via their impacts on the baseline (
e.g.,
as reflected in the density/distribution and status of the species, population size and growth rate, and other relevant stressors).

The preamble of NMFS' implementing regulations also addresses cumulative effects from future, unrelated activities. Such effects are not considered in making the negligible impact determination under MMPA section 101(a)(5). NMFS considers: (1) cumulative effects that are reasonably foreseeable when preparing a National Environmental Policy Act (NEPA) analysis; and (2) reasonably foreseeable cumulative effects under section 7 of the ESA for ESA-listed species, as appropriate. Accordingly, NMFS has adopted and reviewed BOEM's EIS and as part of its inter-agency coordination. This EIS addresses cumulative impacts related to the Project and substantially similar activities in similar locations. Cumulative impacts regarding the promulgation of the regulations and issuance of a LOA for construction activities planned by Avangrid, have been adequately addressed in the adopted EIS that supports NMFS' determination that this action has been appropriately analyzed under NEPA. Separately, the cumulative effects of the Project on ESA-listed species, including the North Atlantic right whale, were analyzed under section 7 of the ESA when NMFS engaged in formal inter-agency consultation with the NOAA Greater Atlantic Regional Field Office (GARFO). The BiOp for the Project determined that NMFS' promulgation of the rulemaking and issuance of an LOA for construction activities, individually and cumulatively, are likely to adversely affect, but not jeopardize, listed marine mammals.

NMFS disagrees that our negligible impact determination is flawed or not supported. NMFS fully disclosed the imperiled status of North Atlantic right whales in the Description of Marine

Mammals in the Area of Specified Activity section of the proposed rule. The proposed rule, as well as this final rule by reference, fully explains the impacts to North Atlantic right whales is expected to be limited to low-level behavioral harassment (
e.g.,
temporary avoidance or cessation of foraging). The proposed rule also described the Potential effects of behavioral disturbance on marine mammal fitness and that, based on the best available science, behavioral disturbance resulting from the specified 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. The commenters do not provide scientific evidence that suggests otherwise. Specifically, the commenters did not provide evidence that any effect to a breeding female would result in reduced fecundity.

Commenters suggested NMFS did not meaningfully evaluate loss of communication space; however, the Effects on Marine Mammals and Their Habitat in the proposed rule contained an analysis on the impacts of masking both in general and from the specified activities. NMFS also disagrees that TTS would result in increased risk of mortality. TTS was fully described in the Potential Effects of Underwater Sound on Marine Mammals and Potential Effects of Disturbance on Marine Mammal Fitness in the proposed rule. NMFS does not anticipate nor authorize serious injury or mortality of any marine mammal species for the specified activities.

NMFS acknowledges that whales may temporarily avoid the area where the specified activities occur. However, NMFS does not anticipate, based on the best available science, that whales will abandon their habitat, as suggested by a commenter, or be displaced in a manner that would result in a higher risk of vessel strike, and the commenter does not provide evidence that either of these effects should be a reasonably anticipated outcome of the specified activity. The primary activity that is anticipated to result in temporary avoidance of the otherwise used habitat is foundation installation pile driving and drilling. Not only would this activity be limited to times of year when North Atlantic right whale presence is low, pile driving and drilling would be intermittent, and only occur for a limited time over the course of 2 or 3 years (depending on schedule type). Together, these factors further reduce the likelihood that this species would be in close enough proximity to the activity to engage in avoidance behavior to the degree it would move into an area of risk (which would be closer to shore) that it could be struck by another vessel.

For NMFS' response on the use of the 160-dB threshold, please see our response to
Comment 3.

Comment 13:
Commenter(s) questioned the validity of NMFS small numbers analysis on the basis that the numbers do not account for the cumulative take numbers from previous, ongoing, or potential projects.

Response:
NMFS has provided a reasoned approach to small numbers, as described in the “Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil and Gas Activities in the Gulf of Mexico” final rule (86 FR 5322 at 5438, April 19, 2021). Utilizing that approach, NMFS has made the necessary small numbers finding for all affected species and stocks in this case (see Small Numbers section for more detail). Neither the MMPA nor our implementing regulations require the small numbers analysis to consider take from previous, ongoing, or potential projects.

Comment 14:
Commenters suggested NMFS failed to account for the cumulative (or additive) impacts on marine mammal species in the analysis and that NMFS should evaluate the cumulative impacts of ongoing and future OSW projects rather than evaluating projects individually, including that NMFS must consider the total number of takes proposed to be authorized across all wind projects. They suggested that NMFS must fully consider the discrete effects of each activity and the cumulative effects of the suite of approved, proposed, and potential activities on marine mammals, including North Atlantic right whales, and ensure that the cumulative effects are not excessive before issuing a LOA.

Response:
Neither the MMPA nor NMFS' implementing regulations call for consideration of the take resulting from other specified activities in the negligible impact analysis. The preamble to NMFS' implementing regulations (54 FR 40338, September 29, 1989) states, in response to comments, that the impacts from other past and ongoing anthropogenic activities are to be incorporated into the negligible impact analysis via their impacts on the baseline. Consistent with that direction, NMFS has factored into its negligible impact analysis the impacts of other past and ongoing anthropogenic activities via their impacts on the baseline (
e.g.,
as reflected in the density/distribution and status of the species, population size and growth rate, and other relevant stressors). The 1989 final rule for the MMPA implementing regulations also addressed public comments regarding cumulative effects from future, unrelated activities. There, NMFS stated that such effects are not considered in making findings under section 101(a)(5) concerning negligible impact. In this case, this ITR, as well as other ITRs currently in effect or proposed within the specified geographical region are appropriately considered an unrelated activity relative to the others. The ITRs are unrelated in the sense that they are discrete actions under section 101(a)(5)(A) issued to discrete applicants. Section 101(a)(5)(A) of the MMPA requires NMFS to make a determination that the take incidental to a “specified activity” will have a negligible impact on the affected species or stocks of marine mammals.

NMFS' implementing regulations require applicants to include in their request a detailed description of the specified activity or class of activities that can be expected to result in incidental taking of marine mammals, 50 CFR 216.104(a)(1). Thus, the “specified activity” for which incidental take coverage is being sought under section 101(a)(5)(A) is generally defined and described by the applicant. Here, Avangrid was the applicant for the ITR, and we are responding to the specified activity as described in that application and making the necessary findings on that basis.

Through the response to public comments in the 1989 implementing regulations (54 FR 40338, September 29, 1989), NMFS also indicated (1) that we would consider cumulative effects that are reasonably foreseeable when preparing a NEPA analysis and (2) that reasonably foreseeable cumulative effects would also be considered under section 7 of the ESA for listed species, as appropriate. Accordingly, NMFS has adopted an EIS written by BOEM and reviewed by NMFS as part of inter-agency coordination. This EIS addresses cumulative impacts related to the Project and substantially similar activities in similar locations. Cumulative impacts regarding the promulgation of the regulations and issuance of a LOA for construction activities, such as those planned by Avangrid, have been adequately addressed under NEPA in the adopted EIS that supports NMFS' determination that this action has been appropriately analyzed under NEPA. Separately, the cumulative effects of the Project on ESA-listed species, including North Atlantic right whales, was analyzed under section 7 of the ESA when NMFS engaged in formal inter-agency

consultation with GARFO. The BiOp for the Project determined that NMFS' promulgation of the rulemaking and issuance of a LOA for construction activities associated with leasing, individually and cumulatively, are likely to adversely affect, but not jeopardize, listed marine mammals.

Comment 15:
Commenter(s) claimed the request for an ITA should be denied alleging the specified activities kill marine mammals and some commenters suggested that the ongoing whale UMEs, including the whale deaths occurring in the winter of 2022-2023, are linked with ongoing offshore wind survey work (
i.e.,
HRG surveys). One commenter claimed the burden of proof is on NMFS to prove, with evidence, that there is no association between HRG surveys and whale injuries, including “rectified diffusion”, deaths or otherwise assume that offshore wind activity has contributed to these deaths. A commenter also asserted that the activities covered by the ITR and associated LOA are reasonably likely to result in Level A take of North Atlantic right whales that are not covered by the authorization's terms.

Response:
Neither the proposed rule or this final rule allow mortality or serious injury of marine mammals to be authorized. The best available science indicates that the anticipated impacts from the specified activities potentially include avoidance, cessation of foraging or communication, TTS and PTS, stress, masking,
etc.
(as described in the Effects of the Specified Activities on Marine Mammals and their Habitat section in the proposed rule). NMFS emphasizes that there is no evidence that noise resulting from offshore wind development-related specified activities would cause marine mammal strandings, and there is no evidence linking recent large whale mortalities and currently ongoing offshore wind activities. The commenters offer no such evidence or other scientific information to substantiate their claim. This point has been well supported by other agencies, including BOEM and the Marine Mammal Commission (Marine Mammal Commission Newsletter, Spring 2023).

There is an ongoing UME for humpback whales along the Atlantic coast from Maine to Florida, which includes animals stranded since 2016, and we provide further information on the humpback UME in the humpback whale subsection in the Description of Marine Mammals in the Specified Geographical Region section of this final rule. Partial or full necropsy examinations were conducted on approximately half of the whales that recently stranded along the U.S. east coast. Necropsies were not conducted on other carcasses because they were too decomposed, not brought to land, or stranded on protected lands (
e.g.,
national and state parks) with limited or no access. Of the whales examined (roughly 90), about 40 percent had evidence of human interaction, either ship strike or entanglement. Vessel strikes and entanglement in fishing gear are the greatest human threats to large whales. The remaining 50 necropsied whales either had an undetermined cause of death (due to a limited examination or decomposition of the carcass) or had other causes of death including parasite-caused organ damage and starvation. The best available science indicates that only Level B harassment, or disruption of behavioral patterns (
e.g.,
avoidance), may occur as a result of the Project's HRG surveys. NMFS emphasizes that there is no credible scientific evidence available suggesting that mortality and/or serious injury is a potential outcome of the planned survey activity.

The proposed rule and this final rule state that no take of North Atlantic right whales by Level A harassment, mortality, or serious injury was requested or proposed for authorization (see the Estimated Take and Negligible Impact Analysis and Determination sections), and they are not expected based on the best available science.

One commenter cited literature as evidence that seismic surveys in the mid to low frequency range can injure whales, can cause decompression sickness (the bends) and can cause rectified diffusion. The Fernandez (2005) paper cited refers to pathology results from necropsies conducted on beaked whales involved in a mass stranding event in the Canary Islands following high intensity military training exercises involving numerous surface warships and several submarines and mid-frequency tactical sonar activities. NMFS acknowledges the effects of these activities described by the commenter are known; however, the activities in that paper are not analogous to HRG surveys that would be conducted by Avangrid to construct the Project, and the information presented by the commenter is not applicable due to many factors (
e.g.,
pile driving is stationary, versus the sound sources cited, and HRG surveys utilize a much lower source level).

Comment 16:
Commenter(s) recommended NMFS consider the impacts of structure presence and operations, including those from operational turbine noise on marine mammals as well as ocean mixing and vibrations on phytoplankton, zooplankton, and the food chain. Commenter(s) suggested that NMFS did not evaluate the long-term operational and maintenance impacts of the project on marine mammals and ignored the best available science demonstrating behavioral impacts to marine mammals from operational turbines; therefore, NMFS' small numbers and negligible impact findings are arbitrary and capricious.

Response:
In the proposed rule, NMFS considered the impacts to marine mammals from operational noise and to their habitat, including prey, from the presence of structures and operations based on the best available science. In this final rule, NMFS has supplemented that analysis with new scientific information that has become available regarding these issues since publishing the proposed rule. This new information does not change our findings. The commenter did not provide scientific evidence that suggests the analysis within the proposed rule was unsupported. NMFS has fully evaluated the potential impacts of both issuing this final rule on marine mammals over the five year effective period of this rulemaking and the potential impacts from long-term operations via the BiOp. We refer the reader to the Effects of the Specified Activities on Marine Mammals and Their Habitat section and the Negligible Impact Determination section in the proposed and this final rule for further details.

Other

Comment 17:
Commenter(s) requested that NMFS consideration of LOAs for offshore wind developers be applied equitably across industries (
e.g.,
fishing industry) and that there be a clear threshold for OSW-related takes regionally and across project phases. In addition, the OSW-industry must be held accountable for incidental takes from construction and operations separately from the take authorizations for managed commercial fish stocks. Commenters) also asserted the OSW industry must be held accountable for their impacts on marine mammals as other industries are (
e.g.,
seasonal closures on fisheries, marine mammal entanglements).

Response:
NMFS considers all ITA requests equally, all takes and regulatory measures are project-specific. NMFS carefully reviews models and take estimate methodology to authorize a number of takes, by species and manner of take that is a likely outcome of the Project. There are several conservative assumptions built into the models to ensure the number of takes

authorized is sufficient based on the description of the Project. Therefore, takes authorized, being specific to a project, are managed separately than takes associated with any other project or industry. Avangrid would be accountable to the measures described in their ITA that were set to achieve “the least practicable impact on such species or stock and its habitat”. These include mitigation, monitoring, and reporting measures (
e.g.,
seasonal closures, gear-specific mitigation measures to avoid entanglements,
etc.
).

Avangrid would be required to submit frequent reports which would identify the number of takes applied to the Project. In the unexpected event that Avangrid exceeds the number of takes authorized for a given species, the MMPA and its implementing regulations state that NMFS shall withdraw or suspend the LOA issued under these regulations, after notice and opportunity for public comment, if it finds the methods of taking or the mitigation, monitoring, or reporting measures are not being substantially complied with, or the taking allowed is having, or may have, more than a negligible impact on the species or stock concerned (16 U.S.C. 1371(a)(5)(B); 50 CFR 216.206(e)). Additionally, failure to comply with the requirements of the LOA may result in civil monetary penalties and knowing violations may result in criminal penalties (16 U.S.C. 1375; 50 CFR 216.206(g)).

Moreover, as noted previously, fishing impacts, and NMFS assessment of them, generally center on entanglement in fishing gear, which is a very acute, visible, and severe impact (
i.e.,
mortality or serious injury). In contrast, the impacts incidental to the specified activities are primarily acoustic in nature and limited to Level A harassment and Level B harassment, there is no anticipated or authorized serious injury or mortality that the fishing industry could theoretically be held accountable for. Any take resulting from the specified activities would not be associated with take authorizations related to commercial fisheries. Neither the MMPA nor our implementing regulations require NMFS to analyze impacts to other industries (
e.g.,
fisheries) from issuance of an ITA pursuant to section 101(a)(5)(A). We note that the New England Wind Final EIS assesses the impacts of both BOEM and NMFS' actions (approving Avangrid's activities and authorizing the associated take of marine mammals, respectively) on the human environment, including to fisheries, and NMFS considered the analysis, as appropriate, in the final decisions under the MMPA. The impacts of commercial fisheries on marine mammals and incidental take for said fishing activities are managed separately from those of non-commercial fishing activities such as offshore wind site characterization surveys, under MMPA section 118.

Comment 18:
Commenter(s) questioned what will happen if incidental take is exceeded, and the implications of it.

Response:
In the unlikely scenario that Avangrid exceeds their authorized take levels, any further take would be unauthorized and therefore, prohibited under the MMPA. Avangrid could request additional incidental take of marine mammals from their specified activities. This would require NMFS to reanalyze its small numbers and negligible impact determinations and may require reinitiation of the BiOp and supplemental NEPA analysis depending on the specific facts.

Comment 19:
Commenter(s) expressed concern about NMFS' ability to conduct marine mammal assessment aerial surveys would be detrimentally impacted as a result of offshore wind structures, thus impacting NMFS' ability to continue using current methods to fulfill its mission of precisely and accurately assessing and managing protected species.

Response:
NMFS and BOEM have collaborated to establish the “Federal Survey Mitigation Strategy for the Northeast U.S. Region” (Hare
et al.,
2022). This interagency effort is intended to guide the development and implementation of a program to mitigate impacts of wind energy development on fisheries surveys. For more information on this effort, please see
https://repository.library.noaa.gov/view/noaa/47925.

Changes From the Proposed to Final Rule

Since the publication of the proposed rule in the
Federal Register
(88 FR 37606, June 8, 2023), NMFS has made changes, where appropriate, in response to public comments and new information provided by Avangrid that are reflected in the regulatory text and preamble text of this final rule. Specifically, as described above, Avangrid refined and updated their acoustic modeling for foundation installation activities since the proposed rule which resulted in changes to the exposure estimates and requested take. These changes are briefly identified below, with more information included in the indicated sections of this final rule:

Changes in Information Provided in the Preamble

The information found in the preamble of the proposed rule was based on the best available information at the time of publication. Since publication of the Proposed Rule, new information has become available, which has been incorporated into this final rule as discussed below.

The following change was made throughout the final rule:

At the request of Park City Wind and consent of Avangrid, references to Park City Wind were replaced with Avangrid and lease number OCS-A 0561 was added, where appropriate, since lease area OCS-A-0534 was segregated.

The following changes were made to the Purpose and Need for Regulatory Action section of the preamble to this final rule:

We have added regulatory definitions under Legal Authority for the Final Action for ease of reference.

The following changes were made to the Summary, Summary of Request and Description of the Specified Activity sections of the preamble to this final rule:

We have included OCS-A 0561 as Avangrid segregated the OCS-A 0534 lease area in to two parts: OCS-A 0534 encompasses phase 1 and 0561 encompasses phase 2.

The following changes are reflected in the Description of Marine Mammals in the Specified Geographical Region section of the preamble to this final rule:

NMFS clarified the boundaries of the specified geographical region such that the Mid-Atlantic Bight is defined as from Cape Hatteras, North Carolina to Cape Cod, Massachusetts and extending into the western Atlantic to the 100-m isobath.

Given the release of NMFS' draft 2023 stock assessment reports (SARs; 89 FR 5495, January 29, 2024), we have updated the population estimate used in the proposed rule (Hayes
et al.,
2023) for the North Atlantic right whale (
Eubalaena glacialis
) from 338 to 340 and the total mortality/serious injury (M/SI) amount from 8.1 to 27.2. This increase is due to the inclusion of undetected M/SI (whereas 8.1 accounted only for detected M/SI). As stated in the 2023 draft SARs, the use of the refined methods of Pace
et al.
(2021), the estimated annual rate of total mortality of adults and juveniles for the period 2016-2020 was 27.2, which is over 3 times larger than the 8.1 total derived from reported mortality and serious injury for the same period.

We have also made updates to the UME summaries for North Atlantic right

whales, humpback whales, minke whales, and phocid seals (pinnipeds).

The following changes are reflected in the Estimated Take, Mitigation, and Monitoring and Reporting sections the preamble to this final rule:

NMFS received a number of modeling and density updates from the applicant since the proposed rule, which resulted in associated changes in the size of harassment zones, take numbers, and mitigation zones. As a result of the updated and refined modeling, we have updated the methods by which distances to NMFS harassment thresholds were estimated, the distances to NMFS harassment thresholds, the exposure estimates based on the updated acoustic modeling, and requested and allowable take amounts (which, generally speaking, went down as a result of these modeling refinements). NMFS notes that there were no changes to the number of foundations, construction schedule, or the assumption of 10 dB of noise attenuation as described in the proposed rule. The modeling and density changes are briefly listed here and described in more detail below:

• Upgraded, more refined take estimation modeling of vibratory pile driving, to reflect that which was presented in the proposed rule for impact pile driving (with animats). The revised modeling for vibratory setting of piles (followed by impact pile driving) replaced the practical spreading loss approach with acoustic modeling; and exposures for impact pile driving and vibratory setting were updated using animal movement modeling. This resulted in a notable reduction in exposure ranges and takes by Level B harassment.

• Upgraded sound source propagation modeling of the impact pile driving source, which resulted in little change in take or mitigation zones. The acoustic modeling was upgraded for impact piling as the previous energy-based parabolic equation model used to compute the near-field equivalent source before long range propagation was revised after the proposed rule using JASCO's Full-Wave PE RAM model (FWRAM) to compute the near-field equivalent source before the long-range propagation was computed (also using FWRAM).

• Upgraded sound source propagation modeling of the drilling activity (in lieu of 15 logR spreading), which resulted in some minor reductions in take. The acoustic updated modeling completed for drilling replaced the previous practical spreading loss approach; exposures were calculated by multiplying the zone of influence (ensonified area) by density.

• Improvements to the apportionment of species takes within species guilds (pilot whales, seals). Updates were made by the applicant to guilded species densities for vibratory setting followed by impact pile driving, impact pile driving alone, and drilling.

• An update to the model assumptions for high frequency species (harbor porpoise). This change reduced the exposure ranges and, subsequently, amount of takes by harassment.

Following the proposed rule, new modeling was performed for vibratory pile driving which replaced the previous practical spreading loss approach that defined the distance to Level B harassment as 50 kilometer (km). For the final rule, acoustic modeling was completed for vibratory setting of piles followed by impact driving, and exposures were modeled using animal movement modeling (animat), mirroring the method described in the proposed rule for impact pile driving. In general, the animat modeling resulted in the exposure distance to Level B harassment per species decreasing (most species' distance to the Level B harassment threshold were around 25 km) and, as marine mammals densities were applied depending on the exposure range using the 95th percentile exposure range (ER
95
%
), exposure estimates and takes decreased. Instead of using a broad 50-km distance for estimating exposure and marine mammal density, such as was done in the proposed rule, the exposure estimates and take applied the marine mammal densities at 10 km, 25 km, or 50 km, using the using the next highest density match to the exposure range. For example, if the ER
95
%
was 8.5 km, the 10 km perimeter would be used. These revisions to the more refined modeling methods of estimating take for vibratory pile driving resulted in notable reductions in the Level B take estimates. The primary model refinement that resulted in the majority of the reduction in exposures and take in this final rule was from this change in vibratory pile driving modeling.

Following the proposed rule, the modeling methodology for impact pile driving was refined. In the prior modeling for impact pile driving, an energy-based parabolic equation (PE) model (JASCO's MONM) was used to compute the near-field equivalent source before long range propagation. For the final rule, JASCO's Full-Wave PE RAM model (FWRAM) was used to compute the near-field equivalent source before the long-range propagation was computed (also using FWRAM). FWRAM is an improvement because it calculates full synthetic pressure waveforms (in the time domain), as opposed to summed energy independent of time. Like MONM, FWRAM is range dependent for range-varying marine acoustic environments and takes environmental inputs (bathymetry, water sound speed profile, and seabed geoacoustic profile) into account. FWRAM computes pressure waveforms via Fourier synthesis of the modeled acoustic transfer function in closely spaced frequency bands, and employs the array starter method to accurately model sound propagation from a spatially distributed source (MacGillivray and Chapman 2012). Ultimately, little difference was observed between the prior sound fields with near-field equivalents computed using MONM versus the current modeling with FWRAM, though FWRAM is expected to be a more accurate model.

As part of the above modeling updates to impact pile driving and vibratory pile driving followed by impact pile driving (MONM to FWRAM modeling), changes resulted in the exposure ranges for high-frequency cetaceans (harbor porpoise). PE based models such as MONM and FWRAM are particularly well suited for modeling the propagation of low frequency sounds, such as impact pile driving, but are limited in terms of the total and upper frequency range they can accurately and efficiently model (Etter, 2012). For this reason, propagation must be modeled to some upper cut-off frequency. Beyond this frequency, a linear extrapolation (or roll-off) can be assumed in order to extend the results to higher frequencies. The slope of this roll-off is based on measured pile driving data and chosen to be conservative. Selection of a proper upper cut-off frequency depends on available computational resources, as well as the specific implementation of the PE method of a particular model (Laws, 2013). Because of this, and inherent differences of the two modeling methodologies, the cut-off used in the original modeling for the proposed rule was 300 Hz, while the cut-off in the revised model is 1,000 Hz. Therefore, the new modeling represents a more accurate methodology for frequencies between 300 and 1,000 Hz, as full propagation modeling is performed in this frequency range, rather than an approximate extrapolation (or roll-off). Both modeling approaches produce the same results at low frequencies where pile driving sound is dominant, but since the conservatively chosen roll-off started at

300 Hz, there is more higher frequency energy in the original model than in the revised model. For this reason, the two approaches produce similar results for low-frequency cetaceans, but the revised modeling results in substantially different exposure ranges for high-frequency cetaceans. Following the proposed rule, new modeling was performed for drilling which replaced the previous practical spreading loss approach that defined the distance to Level B harassment as 16.6 km. For the final rule, acoustic modeling was completed for drilling and exposures were calculated by multiplying the zone of influence (ensonified area) by density. Rather than using practical spreading, sound propagation is modeled using a combination of an energy-based parabolic equation (PE) model (JASCO's MONM) at frequencies up to 1 kHz, and the BELLHOP ray tracing model (Porter and Liu 1994) from 1 to 25 kHz. BELLHOP is a widely used Gaussian beam ray-trace propagation model, which incorporates bathymetry, sound speed profiles, and a simplified representation of the sea bottom; as sub-bottom layers have a negligible influence on the propagation of acoustic waves with frequencies above 1 kHz. Sound attenuation due to seawater absorption was included, which can be important for frequencies greater than 5 kHz. The drill was approximated as a point source located at mid-water depth. Further details regarding MONM are provided below, in the context of pile driving. The density perimeter was determined using the longest 10-dB attenuated 95th percentile acoustic range to the behavioral threshold (R
95
%
) for all locations, rounded up to the nearest 5 km, and then applied around the entire lease area (
i.e.,
7.1 km rounded up to 10 km). This new approach is expected to more accurately capture the spatial extent of the sound fields, as it includes an updated source level (191.6 dB) as well as more sophisticated propagation modeling which accounts for bathymetry, sound speed profiles, interaction with the seabed, and seawater absorption. This refinement in the drilling model also resulted in some minor reductions in exposure and take. Further details can be found in the
Modeling and Take Estimates
section.

In order to better reflect available species data specific to the area, we have also updated the methodology for estimating take for species combined into one guild in the Roberts
et al.
density models (harbor seals, grays seals, long-finned pilot whales, and short-finned pilot whales), by using local abundance data to define how the takes within a guild should be apportioned by species or stock as opposed to using SAR abundance data to define how takes should be apportioned with a guild, and subsequently, updated take by Level B harassment authorized for these species.

As a result of the updated modeling, NMFS has changed (some increases, some decreases) the minimum visibility zone, clearance zones, and shutdown zones for all species during foundation installation activities. The clearance and shutdown zones sizes for each foundation type (
i.e.,
monopile, jacket) are now based on the largest distance to Level A harassment threshold of all the foundation installation methods (
i.e.,
impact pile driving, vibratory pile driving, drilling), with a 20 percent increase to the clearance zone. Avangrid requested, and NMFS has carried forward, zone sizes by the largest foundation type (
i.e.,
monopile, jacket) and hammer size. Lastly, Avangrid did not request different zone sizes based on the 12-m monopile versus the 13-m monopile in their January 2024 Application Update as they did prior to the proposed rule. Instead, Avangrid proposed zone sizes based on the 13-m monopile at 6,000 kJ, though this foundation installation scenario remains unlikely though possible. NMFS has therefore set the zone sizes as the largest across all foundation and hammer sizes for each foundation type (monopile, jacket), regardless if Avangrid choses to install a smaller pile or use a smaller hammer during real-world foundation installation. However, Avangrid may request modifications through adaptive management should sound field verification (SFV) demonstrate noise levels are lower than expected.

As a result of the new modeling, the monopile visual (PSO) and acoustic (PAM) clearance zone sizes for other baleen whales and sperm whale has decreased from 4,700 m for all pile driving and drilling to 3,300 m (all installation methods); the pile driving and drilling shutdown zones has similarly decreased from 4,700 m (12-m) and 5,500 m (13-m) to 2,700 m (all installation methods). The refined modeling for harbor porpoise decreased the zone sizes from 2,300 m (monopile pile driving and drilling) to 250 m, as the maximum injury (ER
95
%
) for harbor porpoise is 240 m. The zone sizes for seals decreased from 1,100 m (monopile impact pile driving) and 1,400 m (monopile vibratory pile driving or drilling) to 200 m (all monopiles and installation methods) as the maximum injury (ER
95
%
) for seals was 0 m. The clearance and shutdown zones for small whales and dolphins remain unchanged (200 m) as the maximum injury (ER
95
%
) is 0 m. For those species that modeling resulted in less than 200 m Level A harassment distance to threshold, NMFS has set the minimum clearance and shutdown zone size as 200 m to ensure the zones are outside the monopile's noise attenuation system (NAS). This was also the approach in the proposed rule.

Based on the model changes above, the updated jacket (all pin piles) visual (PSO) and acoustic (PAM) clearance zone sizes for other baleen whales and sperm whale has increased from 4,500 m for impact pile driving and 4,700 m for vibratory pile driving and drilling to 4,900 m (all installation methods); the pile driving and drilling shutdown zones has decreased from 4,500 m for impact pile driving and 4,700 m for vibratory pile driving and drilling to 4,100 m (all installation methods). The refined modeling for harbor porpoise decreased the zone sizes from 1,800 m (impact pile driving) and 2,300 m (vibratory pile driving and drilling) to 250 m as the maximum injury (ER
95
%
) for harbor porpoise is 230 m. The zone sizes for seals decreased from 1,400 m (all pile driving and drilling) to 1,000 m (clearance) and 800 m (shutdown) for all installation methods as the maximum injury (ER
95
%
) for seals was 790 m. The clearance and shutdown zones for small whales and dolphins remain unchanged (50 m) as the maximum injury (ER
95
%
) was 0 m. For those species that modeling resulted in less than 50 m Level A harassment distance to threshold, NMFS has set the minimum clearance and shutdown zone size as 50 m to ensure the zones are outside the jacket's noise attenuation system (NAS). This was also the approach in the proposed rule.

NMFS has not changed the North Atlantic right whale shutdown and clearance zones for visual observations (
i.e.,
any distance), NMFS has set the acoustic clearance and shutdown zones during foundation activities for North Atlantic right whale to any acoustic detection within a 12-km acoustic monitoring zone which were previously set to 5,600 m (monopile impact pile driving), 4,500 m (monopile vibratory pile driving and drilling), and 4,500 m (jacket pile driving and drilling). This final rule also clarifies that PAM must be conducted before, during, and after foundation installation and UXO/MEC detonation for North Atlantic right whales but the PAM system should be designed to detect all other marine mammals to the maximum extent practicable.

We updated the minimum visibility zone based on the new modeling from Avangrid (largest ER
95
%
distance to Level A harassment for low-frequency cetacean, not including fin whale), for all species during each foundation installation type then rounded for PSO clarity. As a result of the new modeling, the final rule sets the minimum visibility zone for monopiles at 2,100 m (humpback whale, 2,070 m), 3,400 m for jacket installation (humpback whale, 3,320 m), and 500 m for HRG (unchanged from the proposed rule). As described in the preamble of the proposed rule (page 405), NMFS originally set the minimum visibility zone size based on the North Atlantic right whale ER
95
%
distance to the Level A harassment threshold, assuming 10 dB. NMFS recognizes that a footnote in table 35 of the proposed rule used incorrect terminology stating that the minimum visibility zone for North Atlantic right whale would be “any distance” which contradicted the earlier stated methodology for setting the minimum visibility zone and would not be practicable. As a result of the updated modeling, the minimum visibility zone in this final rule decreased, however, it is still larger than the updated North Atlantic right whale ER
95
%
distance to the Level A harassment threshold, assuming 10 dB. To align with the BiOp, NMFS has used the largest ER
95
%
distance to Level A harassment for low-frequency cetacean, not including fin whale, which uses the distance to Level A harassment for humpback whale which is greater than the ER
95
%
distance to Level A harassment for North Atlantic right whale (monopile 2,070 m vs 1,620 m; jacket 3,320 m vs 2,350 m).

We have reduced takes by Level B harassment for Northern bottlenose whale from 12 to 8 as a r

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2024-12085. Public record. Not legal advice.