[Federal Register Volume 88, Number 96 (Thursday, May 18, 2023)]
[Notices]
[Pages 31718-31737]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-10639]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC871]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Marine Site Characterization 
Surveys in the New York Bight and Central Atlantic

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

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ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an Incidental Harassment Authorization (IHA) to 
TerraSond Limited (TerraSond) to incidentally harass marine mammals 
during marine site characterization surveys in the New York Bight (off 
of New York and New Jersey) and in the Central Atlantic (from Delaware 
to North Carolina).

DATES: This authorization is effective from April 1, 2024, through 
March 31, 2025.

FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: 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.

SUPPLEMENTARY INFORMATION:

Background

    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 and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

Summary of Request

    On May 19, 2022, NMFS received a request from TerraSond for an IHA 
to take marine mammals incidental to site characterization surveys in 
the New York Bight. Following NMFS' review of the application, 
TerraSond submitted a revised version on July 11, 2022, adding 
additional planned survey activity in the Central Atlantic. This 
revised application was deemed adequate and complete. TerraSond's 
request is for take of 21 species of marine mammals, by Level B 
harassment only. Neither TerraSond nor NMFS expect serious injury or 
mortality to result from this activity and, therefore, an IHA is 
appropriate. There are no changes from the proposed IHA to the final 
IHA.

Description of Activity

Overview

    TerraSond plans to conduct marine site characterization surveys, 
including high-resolution geophysical (HRG) surveys, off the coasts of 
New Jersey and New York (New York Bight) and from Delaware to North 
Carolina (Central Atlantic). The former portion of survey effort would 
be conducted on Bureau of Ocean Energy Management (BOEM) Lease Areas 
OCS-A 0539, 0541, and 0542, while the latter portion of survey effort 
would be conducted in continental shelf waters of BOEM's Central 
Atlantic Call Area. The planned survey effort would be conducted in 
support of wind energy development.
    NMFS notes that, on November 16, 2022, BOEM announced eight draft 
Wind Energy Areas (WEAs), covering approximately 1.7 million acres 
(688,000 hectares), in the Central Atlantic for public review and 
comment. The eight draft WEAs represent a subset of the original 3.9 
million acres of the Call Area that the Department of the Interior 
announced for public comment in April 2022. Therefore, TerraSond's 
actual survey effort in the Central Atlantic, which would be dictated 
by commercial interest, is likely to be less than that described in its 
application.
    The planned marine site characterization survey effort is designed 
to obtain data sufficient to meet BOEM guidelines for providing 
geophysical, geotechnical, and geohazard information for site 
assessment plan surveys and/or construction and operations plan 
development. The objective of the surveys is to acquire data on 
bathymetry, seafloor morphology, subsurface geology, environmental/
biological sites, seafloor obstructions, soil conditions, and locations 
of any man-made, historical or archaeological resources within the 
respective survey areas. Underwater sound resulting from TerraSond's 
potential site characterization survey activities, specifically HRG 
surveys, has the potential to result in incidental take of marine 
mammals in the form of Level B behavioral harassment.

Dates and Duration

    The potential duration of Central Atlantic HRG survey activity is 
expected to include a maximum of 1,052 survey days (minimum 661 survey 
days, depending on final survey plan) over the course of the 1-year 
period of effectiveness for the IHA, with a ``survey day'' defined as a 
24-hour (hr) activity period in which active acoustic sound sources are 
used. The potential duration of New York Bight survey activity is 
expected to include a maximum of 385 survey days. Therefore, the 
potential total survey days would range from 1,046 to a maximum of 
1,437. For both components of the activity, survey activities are 
anticipated to occur over a minimum of 6-8 months using multiple 
vessels concurrently and likely throughout most of a year. TerraSond 
plans to start survey activity as soon as possible, with the IHA 
effective for a period of 1 year.

Specific Geographic Region

    The planned survey activities will occur within the aforementioned 
BOEM Central Atlantic Call Area and within BOEM's Lease Areas OCS-A 
0539, 0541, and 0542 in the New York Bight. Please see Figures 1 and 2 
below or, for color versions, see the same figures in TerraSond's 
application. The Central Atlantic survey area comprises approximately 
11,500 square kilometers (km\2\), covering water depths from 20-60 
meters (m), and the New York Bight survey area comprises approximately 
1,171 km\2\, covering water depths from 30-65 m. As mentioned above, 
based on BOEM's contraction of the likely wind energy development area 
(relative to the initial proposed Call Area), it is likely that actual 
survey effort in the Central Atlantic may be less than that described 
in TerraSond's application.
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TN18MY23.000


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[GRAPHIC] [TIFF OMITTED] TN18MY23.001

BILLING CODE 3510-22-C

Detailed Description of Specific Activity

    TerraSond plans to conduct HRG survey operations, including 
multibeam depth sounding, seafloor imaging, and shallow and medium 
penetration sub-bottom profiling. The HRG surveys may be conducted 
using any or all of the following equipment types: side scan sonar, 
multibeam echosounder, gradiometers, parametric sub-bottom profiler, or 
sparkers. TerraSond assumes that HRG survey operations would be 
conducted 24 hours per day, with an assumed daily survey distance of 
100 km. This average distance per day was calculated by TerraSond from 
the maximum achievable survey distance assuming 24-hour survey 
operations and an average vessel speed of 3.5 knots (kn) (6.5 km/hour), 
and then reducing from there based on prior experience to account for 
expected downtime related

[[Page 31722]]

to weather, equipment malfunction, and other factors.
    The only acoustic source planned for use during HRG survey 
activities planned by TerraSond with expected potential to cause 
incidental take of marine mammals is the sparker. Sparkers are medium 
penetration, impulsive sources used to map deeper subsurface 
stratigraphy, and which may be operated with different numbers of 
electrode tips to allow tuning of the acoustic waveform for specific 
applications. Sparkers create omnidirectional acoustic pulses from 50 
Hz to 4 kHz, and are typically towed behind the vessel. The sparker 
system planned for use is the Applied Acoustics Dura-Spark Ultra-High 
Resolution Seismic (UHRS) 400 + 400 (electrode tips) source, which is 
essentially two of the same Applied Acoustics Dura-Spark sources 
stacked on top of each other creating two ``decks'' to the sparker. 
However, the decks will not be discharged simultaneously, but will be 
used in an alternating ``flip-flop'' pattern (as discussed below). 
Thus, for all source configurations below, the maximum power expected 
when discharging the sparker source (single deck) will be 800 joules 
(J). Crocker and Fratantonio (2016) measured the Applied Acoustics 
Dura-Spark, but did not provide data for an energy setting near 800 J 
(for a 400-tip configuration, Crocker and Fratantonio (2016) provide 
measurements at 500 and 2,000 J). Therefore, TerraSond uses a similar 
alternative system, which was measured with an input voltage of 750 J, 
as a surrogate for purposes of analysis. NMFS concurs with this 
selection, which is described in Table 1.

                                                    Table 1--Summary of Representative HRG Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Operating                                           Pulse  duration
              Equipment                  frequency      SLrms  (dB re 1    SL0-pk  (dB re 1       (width)        Repetition       Beamwidth  (degrees)
                                           (kHz)           [mu]Pa m)          [mu]Pa m)       (millisecond)    rate  (second)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SIG ELC 820 sparker (750 J) \1\.....         0.3-1.2                203                213              1.1             0.25   Omni
--------------------------------------------------------------------------------------------------------------------------------------------------------
[mu]Pa = micropascal; dB = decibel; Omni = omnidirectional source; re = referenced to; PK = zero-to-peak sound pressure level; SL = source level; SPL =
  root-mean-square sound pressure level.
\1\ Proxy for Applied Acoustics Dura-Spark UHRS (800 J).

    Central Atlantic--The Central Atlantic activity component includes 
two different survey phases that may occur involving different survey 
line spacing and potential survey equipment tow configurations. There 
are two possible survey methods that may be used during Phase 1, which 
the applicant refers to as Alternative 1 and Alternative 2. Alternative 
1 would involve the use of a single source vessel towing one sparker 
source composed of two ``decks'' of 400 electrode tips each stacked on 
top of each other. The two decks would be discharged in alternating 
fashion such that only one deck is discharged at a time. Alternative 2 
would involve the use of a single source vessel towing 3 of the same 
sparker sources with a horizontal separation between the sources of 150 
m. Alternative 1 describes acquisition along 58,607 km of trackline, 
while Alternative 2 describes acquisition along 19,536 km of trackline. 
Only one of these two methods will be used for survey acquisition. 
Phase 2 will involve a single vessel towing two of the same sparker 
sources with a horizontal separation between the sources of 30 m, and 
includes acquisition along 46,573 km of trackline. At an assumed 100 km 
per day, Phase 1 would require approximately 586 or 195 days, depending 
on which alternative is ultimately used, and Phase 2 will require 
approximately 466 days. Therefore, based on the description provided by 
TerraSond, the Central Atlantic portion of the survey effort is 
expected to require either 661 or 1,052 survey days. Up to a total of 
four source vessels may be active concurrently to accomplish this.
    New York Bight--The New York Bight activity component includes 
three different survey phases that may occur involving different survey 
line spacing and potential survey equipment tow configurations. Phase 1 
involves the use of a single source vessel towing one sparker source 
composed of two ``decks'' of 400 electrode tips each stacked on top of 
each other. As discussed above, the two decks will typically be 
discharged in alternating fashion such that only one deck is discharged 
at a time. Phases 2 and 3 involve a single vessel towing two of the 
same sparker sources with a horizontal separation between the sources 
of 30 m. These Phases involve acquisition along 14,833, 200, and 23,311 
km of trackline, respectively, requiring a total of approximately 385 
days. Up to a total of three source vessels may be active concurrently 
to accomplish this.
    Further detail regarding the planned HRG surveys is provided in the 
Federal Register notice for the proposed IHA (87 FR 66658; November 4, 
2022). Since that time, no changes have been made to the planned HRG 
survey activities. Required mitigation, monitoring, and reporting 
measures are described in detail later in this document (please see 
Mitigation and Monitoring and Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to TerraSond was 
published in the Federal Register on November 4, 2022 (87 FR 66658) for 
a 30-day comment period. That notice described, in detail, TerraSond's 
planned activities, the marine mammal species that may be affected by 
the activities, and the anticipated effects on marine mammals. In that 
notice, we requested public input on the request for authorization 
described therein, our analyses, the proposed authorization, and other 
aspects of the notice of proposed IHA, and requested that interested 
persons submit relevant information, suggestions, and comments.
    NMFS received two comment letters from private citizens, expressing 
general opposition to issuance of the IHA or to the underlying 
associated activities. The comments received suggested that NMFS should 
not issue the IHA, but without providing information relevant to NMFS' 
decision. We reiterate here that NMFS' proposed action concerns only 
the authorization of marine mammal take incidental to the planned 
surveys--NMFS' authority under the MMPA does not extend to the surveys 
themselves, or to wind energy development more generally. Further, NMFS 
does not have discretion regarding issuance of requested incidental 
take authorizations pursuant to the MMPA, assuming: (1) the total 
taking associated with a specified activity will have a negligible 
impact on

[[Page 31723]]

the affected species or stock(s); (2) the total taking associated with 
a specified activity will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (not 
relevant here); (3) the total taking associated with a specified 
activity is small numbers of marine mammals of any species or stock; 
and (4) appropriate mitigation, monitoring, and reporting of such 
takings are set forth, including mitigation measures sufficient to meet 
the standard of least practicable adverse impact on the affected 
species or stocks. In addition, one commenter suggested that issuance 
of the proposed IHA could result in the death of ``whales.'' We 
reiterate here that no mortality is anticipated or authorized, and note 
that the commenter did not provide any specific information supporting 
this concern.
    NMFS also received letters from two non-governmental organizations, 
Oceana and the Southern Environmental Law Center (SELC), and from the 
Delaware Department of Natural Resources and Environmental Control 
(DNREC). SELC's comments were submitted on behalf of an additional nine 
organizations. All substantive comments, and NMFS' responses, are 
provided below, and all letters are available online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-terrasond-limited-marine-site-characterization-surveys-new. Please review the 
letters for full details regarding the comments and underlying 
justification.
    Comment: Oceana raised objections to NMFS' proposed renewal process 
for potential extension of the 1-year IHA with an abbreviated 15-day 
public comment period. Oceana recommended that an additional 30-day 
public comment period is necessary for any IHA renewal request.
    Response: NMFS' IHA renewal process meets all statutory 
requirements. In prior responses to comments about IHA renewals (e.g., 
84 FR 52464, October 2, 2019 and 85 FR 53342, August 28, 2020), NMFS 
explained the IHA renewal process is consistent with the statutory 
requirements contained in section 101(a)(5)(D) of the MMPA, and 
further, promotes NMFS' goals of improving conservation of marine 
mammals and increasing efficiency in the MMPA compliance process. 
Therefore, we intend continue to implement the existing renewal 
process.
    All IHAs issued, whether an initial IHA or a renewal, are valid for 
a period of not more than one year. And the public has 30 days to 
comment on proposed IHAs, with a cumulative total of 45 days for IHA 
renewals. The notice of the proposed IHA published in the Federal 
Register on November 4, 2022 (87 FR 66658) provided a 30-day public 
comment period and made clear that NMFS was seeking comment on the 
proposed IHA and the potential issuance of a renewal for this survey. 
As detailed in the Federal Register notice for the proposed IHA and on 
the agency's website, eligibility for renewal is determined on a case-
by-case basis, renewals are subject to an additional 15-day public 
comment period, and the renewal is limited to up to another year of 
identical or nearly identical activities as described in the 
Description of Proposed Activities section of the proposed IHA notice 
or the activities described in the Description of Proposed Activities 
section of the proposed IHA notice would not be completed by the time 
the IHA expires and a renewal would allow for completion of the 
activities beyond that described in the Dates and Duration section of 
this notice. NMFS' analysis of the anticipated impacts on marine 
mammals caused by the applicant's activities covers both the initial 
IHA period and the possibility of a 1-year renewal. Therefore, a member 
of the public considering commenting on a proposed initial IHA also 
knows exactly what activities (or subset of activities) would be 
included in a proposed renewal IHA, the potential impacts of those 
activities, the maximum amount and type of take that could be caused by 
those activities, the mitigation and monitoring measures that would be 
required, and the basis for the agency's negligible impact 
determinations, least practicable adverse impact findings, small 
numbers findings, and (if applicable) the no unmitigable adverse impact 
on subsistence use finding--all the information needed to provide 
complete and meaningful comments on a possible renewal at the time of 
considering the proposed initial IHA. Reviewers have the information 
needed to meaningfully comment on both the immediate proposed IHA and a 
possible 1-year renewal, should the IHA holder choose to request one.
    While there would be additional documents submitted with a renewal 
request, for a qualifying renewal these would be limited to 
documentation that NMFS would make available and use to verify that the 
activities are identical to those in the initial IHA, are nearly 
identical such that the changes would have either no effect on impacts 
to marine mammals or decrease those impacts, or are a subset of 
activities already analyzed and authorized but not completed under the 
initial IHA. NMFS would also need to confirm, among other things, that 
the activities would occur in the same location; involve the same 
species and stocks; provide for continuation of the same mitigation, 
monitoring, and reporting requirements; and that no new information has 
been received that would alter the prior analysis. The renewal request 
would also contain a preliminary monitoring report, in order to verify 
that effects from the activities do not indicate impacts of a scale or 
nature not previously analyzed. The additional 15-day public comment 
period, which includes NMFS' direct notice to anyone who commented on 
the proposed initial IHA, provides the public an opportunity to review 
these few documents, provide any additional pertinent information, and 
comment on whether they think the criteria for a renewal have been met. 
Combined together, the 30-day public comment period on the initial IHA 
and the additional 15-day public comment period on the renewal of the 
same or nearly identical activities, provides the public with a total 
of 45 days to comment on the potential for renewal of the IHA.
    In addition to the IHA renewal process being consistent with all 
requirements under section 101(a)(5)(D), it is also consistent with 
Congress' intent for issuance of IHAs to the extent reflected in 
statements in the legislative history of the MMPA. Through the 
description of the process and express invitation to comment on 
specific potential renewals in the Request for Public Comments section 
of each proposed IHA, the description of the process on NMFS' website, 
further elaboration on the process through responses to comments such 
as these, posting of substantive documents on the agency's website, and 
provision of 30 or 45 days for public review and comment on all 
proposed initial IHAs and renewals respectively, NMFS has ensured that 
the public is ``invited and encouraged to participate fully in the 
agency's decision-making process,'' as Congress intended.
    Comment: Oceana stated that NMFS must utilize the best available 
scientific evidence, and suggested that NMFS has not done so, 
specifically referencing information regarding the North Atlantic right 
whale (NARW) such as updated population estimates, habitat usage in the 
survey area, and seasonality information. Oceana specifically asserted 
that NMFS is not using the best available scientific evidence with 
regards to the NARW population estimate.

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    Response: NMFS agrees the best available scientific evidence should 
be used for assessing NARW abundance estimates. Following the recent 
publication of NMFS' draft 2022 Stock Assessment Reports (SAR), NMFS 
updated the information relied upon herein accordingly. In prior 
responses to comments, NMFS has found that the SAR is the best 
available scientific evidence with respect to NARW population estimates 
(see e.g., 87 FR 25452). We find no reason to reconsider or depart from 
this.
    Moreover, the draft 2022 SARs report the same NARW abundance 
estimate (336) cited by Oceana in its public comment. We further note 
that this change in abundance estimate does not change the estimated 
take of NARWs or authorized take numbers, nor does it affect our 
ability to make the required findings under the MMPA for TerraSond's 
survey activities.
    In sum, NMFS considered the best available scientific evidence 
regarding both recent habitat usage patterns for the study area and up-
to-date seasonality information in the notice of the proposed IHA, 
including consideration of existing biologically important areas (BIAs) 
and densities provided by Roberts and Halpin (2022). While the 
commenter has suggested that NMFS consider best available scientific 
evidence for recent habitat usage patterns and seasonality, the 
commenter has not offered any additional scientific information that it 
suggests should be considered best available scientific evidence.
    Comment: Oceana noted that chronic stressors are an emerging 
concern for NARW conservation and recovery, and stated that chronic 
stress may result in energetic effects for NARWs. Oceana suggested that 
NMFS has not fully considered both the use of the area and the effects 
of both acute and chronic stressors on the health and fitness of NARWs, 
as disturbance responses in NARWs could lead to chronic stress or 
habitat displacement, leading to an overall decline in their health and 
fitness.
    Response: NMFS agrees with Oceana that both acute and chronic 
stressors are of concern for NARW conservation and recovery. We 
recognize that acute stress from acoustic exposure is one potential 
impact of these surveys, and that chronic stress can have fitness, 
reproductive, etc. impacts at the population-level scale. NMFS has 
carefully reviewed the best available scientific information in 
assessing impacts to marine mammals, and recognizes that the surveys 
have the potential to impact marine mammals through behavioral effects, 
stress responses, and auditory masking. However, NMFS does not expect 
that the generally short-term, intermittent, and transitory marine site 
characterization survey activities planned by TerraSond will create 
conditions of acute or chronic acoustic exposure leading to long-term 
physiological stress responses in marine mammals. NMFS has prescribed a 
robust suite of mitigation measures, including extended distance 
shutdowns for NARW, that are expected to further reduce the duration 
and intensity of acoustic exposure, while limiting the potential 
severity of any possible behavioral disruption. The potential for 
chronic stress was evaluated in making the determinations presented in 
NMFS' negligible impact analyses. Because NARW generally use this 
location in a transitory manner, specifically for migration, any 
potential impacts from these surveys are lessened for other behaviors 
due to the brief periods where exposure is possible. Thus, the 
transitory nature of occurrence of NARWs as they migrate means it is 
unlikely for any exposure to cause chronic effects, as TerraSond's 
planned survey area and ensonified zones are small relative to the 
overall migratory corridor. As such, NMFS does not expect acute or 
cumulative stress to be a detrimental factor to NARWs from TerraSond's 
described survey activities.
    Lastly, NMFS does not find that the effects of TerraSond's survey 
may contribute to stunted growth rates as suggested by Oceana's 
comments. The activities associated with TerraSond's survey are outside 
the scope of activities described in the Stewart et al. (2021) paper, 
which finds that entanglements in fishing gear are associated with 
shorter whales. There is no evidence suggesting that the survey 
activities considered herein could have energetic effects similar to 
those caused by entanglement in fishing gear. Therefore, NMFS does not 
expect stunted growth rates to result from TerraSond's described survey 
activities.
    Comment: Oceana suggests that all vessels associated with the 
proposed survey should be required to carry and use protected species 
observers (PSOs), and that PSOs complement their survey efforts using 
additional technologies, such as infrared detection devices when in 
low-light conditions.
    Response: NMFS finds that it is unnecessary for all survey vessels 
to use PSOs. PSOs are generally reserved for use onboard acoustic 
source vessels, where PSOs are responsible for conducting observations, 
notifying the crew of the need to implement mitigation measures, and 
recording data. In circumstances similar to those associated with 
TerraSond's proposed activities, watchstanders are fully capable of 
conducting watch for purposes of avoiding vessel strike of any objects, 
including marine mammals. NMFS does, however, agree with Oceana about 
the use of night vision devices. As such, a requirement to utilize at 
least one thermal (infrared) imaging device during low-light conditions 
was included in the proposed Federal Register notice. That requirement 
is included as a requirement of the issued IHA.
    Comment: Oceana recommends that NMFS restrict all vessels of all 
sizes associated with the proposed survey activities to speeds less 
than 10 kn (18.5 km/hour) at all times due to the risk of vessel 
strikes to NARWs and other large whales.
    Response: While NMFS acknowledges that vessel strikes can result in 
injury or mortality, we have analyzed the potential for vessel strike 
resulting from TerraSond's activity and have determined that based on 
the nature of the activity and the required mitigation measures 
specific to vessel strike avoidance included in the IHA, potential for 
vessel strike is so low as to be discountable. The required mitigation 
measures, all of which were included in the proposed IHA and are now 
required in the final IHA, include: (1) a requirement that all vessel 
operators comply with 10 kn (18.5 km/hour) or less speed restrictions 
in any SMA, DMA or Slow Zone while underway, and check daily for 
information regarding the establishment of mandatory or voluntary 
vessel strike avoidance areas (SMAs, DMAs, Slow Zones) and information 
regarding NARW sighting locations; (2) a requirement that all vessels 
greater than or equal to 19.8 m in overall length operating from 
November 1 through April 30 operate at speeds of 10 kn (18.5 km/hour) 
or less; (3) a requirement that all vessel operators reduce vessel 
speed to 10 kn (18.5 km/hour) or less when any large whale, any mother/
calf pairs, pods, or large assemblages of non-delphinid cetaceans are 
observed near the vessel; (4) a requirement that all survey vessels 
maintain a separation distance of 500 m or greater from any Endangered 
Species Act (ESA)-listed whales or other unidentified large marine 
mammals visible at the surface while underway; (5) a requirement that, 
if underway, vessels must steer a course away from any sighted ESA-
listed whale at 10 kn or less until the 500 m minimum separation 
distance has been established; (6) a requirement that, if an

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ESA-listed whale is sighted in a vessel's path, or within 500 m of an 
underway vessel, the underway vessel must reduce speed and shift the 
engine to neutral; (7) a requirement that all vessels underway must 
maintain a minimum separation distance of 100 m from all non-ESA-listed 
baleen whales; and, (8) a requirement that all vessels underway must, 
to the maximum extent practicable, attempt to maintain a minimum 
separation distance of 50 m from all other marine mammals, with an 
understanding that at times this may not be possible (e.g., for animals 
that approach the vessel). We have determined that the vessel strike 
avoidance measures in the IHA are sufficient to ensure the least 
practicable adverse impact on species or stocks and their habitat. 
Furthermore, no documented vessel strikes have occurred for any marine 
site characterization surveys, which were issued IHAs from NMFS during 
the survey activities themselves or while transiting to and from survey 
sites.
    Comment: Oceana suggests that NMFS require vessels maintain a 
separation distance of at least 500 m from NARWs at all times.
    Response: NMFS agrees with Oceana regarding this suggestion and a 
requirement to maintain a separation distance of at least 500 m from 
NARWs at all times was included in the proposed Federal Register notice 
and was included as a requirement in the issued IHA.
    Comment: Oceana recommended that the IHA should require all vessels 
supporting site characterization to be equipped with and use Class A 
Automatic Identification System (AIS) devices at all times while on the 
water. Oceana suggested this requirement should apply to all vessels, 
regardless of size, associated with the survey.
    Response: NMFS is generally supportive of the idea that vessels 
involved with survey activities be equipped with and use Class A AIS 
devices at all times while on the water. Indeed, there is a precedent 
for NMFS requiring such a stipulation for geophysical surveys in the 
Atlantic Ocean (83 FR 63268, December 7, 2018); however, these seismic 
surveys carried the potential for much more significant impacts than 
the marine site characterization surveys planned by TerraSond. Given 
the comparatively small footprint of potential effects and 
correspondingly low level of concern regarding HRG survey activities, 
NMFS has determined that the operational costs associated with a 
requirement to so equip vessels not otherwise required to carry AIS are 
not warranted under the MMPA's least practicable adverse impact 
standard.
    Comment: Oceana asserts that the IHA must include requirements to 
hold all vessels associated with site characterization surveys 
accountable to the IHA requirements, including vessels owned by the 
developer, contractors, employees, and others regardless of ownership, 
operator, and contract. They state that exceptions and exemptions will 
create enforcement uncertainty and incentives to evade regulations 
through reclassification and redesignation. They recommend that NMFS 
simplify this by requiring all vessels to abide by the same 
requirements, regardless of size, ownership, function, contract, or 
other specifics.
    Response: NMFS agrees with Oceana and the proposed IHA and final 
IHA has general conditions to hold TerraSond and its designees 
(including vessel operators and other personnel) accountable while 
performing operations under the authority of the IHA. The plain 
language of the IHA indicates that the conditions contained therein 
apply to TerraSond and its designees. The IHA requires that a copy of 
the IHA must be in the possession of TerraSond, the vessel operators, 
the lead PSO, and any other relevant designees of TerraSond operating 
under the authority of this IHA. The IHA also states that TerraSond 
must ensure that the vessel operator and other relevant vessel 
personnel, including the PSO team, are briefed on all responsibilities, 
communication procedures, marine mammal monitoring protocols, 
operational procedures, and IHA requirements prior to the start of 
survey activity, and when relevant new personnel join the survey 
operations.
    Comment: Oceana stated that the IHA must include a requirement for 
all phases of the survey to subscribe to the highest level of 
transparency, including frequent reporting to federal agencies. Oceana 
recommends requirements to report all visual and acoustic detections of 
NARWs and any dead, injured, or entangled marine mammals to NMFS or the 
Coast Guard as soon as possible and no later than the end of the PSO 
shift, and also states that to foster stakeholder relationships and 
allow public engagement and oversight of the permitting, the IHA should 
require all reports and data to be accessible on a publicly available 
website.
    Response: NMFS agrees with the need for reporting and, indeed, the 
MMPA calls for IHAs to incorporate reporting requirements. As included 
in the proposed IHA, the final IHA includes requirements for reporting 
that supports Oceana's recommendations. TerraSond is required to submit 
a monitoring report to NMFS within 90 days after completion of survey 
activities that fully documents the methods and monitoring protocols, 
summarizes the data recorded during monitoring. PSO datasheets or raw 
sightings data must also be provided with the draft and final 
monitoring report.
    Further, the draft IHA and final IHA stipulate that if a NARW is 
observed at any time by any survey vessels, during surveys or during 
vessel transit, TerraSond must immediately report sighting information 
to the NMFS North Atlantic Right Whale Sighting Advisory System within 
two hours of occurrence, when practicable, or no later than 24 hours 
after occurrence. TerraSond may also report the sighting to the U.S. 
Coast Guard. Additionally, TerraSond must report any discoveries of 
injured or dead marine mammals to the Office of Protected Resources, 
NMFS, and to the New England/Mid-Atlantic Regional Stranding 
Coordinator as soon as feasible. This includes entangled animals. All 
reports and associated data submitted to NMFS are included on the 
website for public inspection.
    Daily visual and acoustic detections of NARWs and other large whale 
species along the Eastern Seaboard, as well as Slow Zone locations, are 
publicly available on WhaleMap (https://whalemap.org/WhaleMap/). 
Further, recent acoustic detections of NARWs and other large whale 
species are available to the public on NOAA's Passive Acoustic Cetacean 
Map website https://apps-nefsc.fisheries.noaa.gov/pacm/#/narw.
    Comment: Oceana recommended that NMFS require a visual clearance 
zone of at least 1,000 m for NARWs around each vessel, and also require 
an acoustic clearance and exclusion zone of at least 1,000 m for NARWs. 
In contrast, DNREC commended the use of exclusion zones as proposed by 
NMFS, but also noted its support for the use of passive acoustic 
monitoring (PAM) as a supplementary monitoring technique.
    Response: NMFS notes that the 500 m shutdown zone for NARWs exceeds 
the modeled distance to the largest 160 dB Level B harassment isopleth 
(141 m during sparker use) by a substantial margin. Oceana does not 
provide a compelling rationale for why the shutdown zone should be even 
larger. Given that these surveys are relatively low impact and that, 
regardless, NMFS has prescribed a NARW shutdown zone that is 
significantly larger (500 m) than the conservatively estimated largest 
harassment zone (141 m), NMFS has determined that the shutdown zone is 
appropriate. Further, Level A

[[Page 31726]]

harassment is not expected to result even in the absence of mitigation, 
given the characteristics of the sources planned for use.
    Regarding the use of acoustic monitoring to implement the exclusion 
zones, NMFS does not anticipate that acoustic monitoring would be 
effective for a variety of reasons discussed below and therefore has 
not required it in this IHA. As described in the Mitigation section, 
NMFS has determined that the prescribed mitigation requirements are 
sufficient to effect the least practicable adverse impact on all 
affected species or stocks.
    The commenters do not explain why they expect that PAM would be 
effective in detecting vocalizing mysticetes, nor does NMFS agree that 
this measure is warranted, as it is not expected to be effective for 
use in detecting the species of concern. It is generally accepted that, 
even in the absence of additional acoustic sources, using a towed 
passive acoustic sensor to detect baleen whales (including NARWs) is 
not typically effective because the noise from the vessel, the flow 
noise, and the cable noise are in the same frequency band and will mask 
the vast majority of baleen whale calls. 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 decibel (dB) referenced to 1 micropascal (re 1 [mu]Pa) at 1 m (NRC, 
2003; Hildebrand, 2009), depending on factors such as ship type, load, 
and speed, and ship 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). PAM systems employ hydrophones towed in streamer cables 
approximately 500 m behind a vessel. Noise from water flow around the 
cables and from strumming of the cables themselves is also low 
frequency and typically masks signals in the same range. Experienced 
PAM operators participating in a recent workshop (Thode et al., 2017) 
emphasized that a PAM operation could easily report no acoustic 
encounters, depending on species present, simply because background 
noise levels rendered any acoustic detection impossible. The same 
workshop report stated that a typical eight-element array towed 500 m 
behind a vessel could be expected to detect delphinids, sperm whales, 
and beaked whales at the required range, but not baleen whales, due to 
expected background noise levels (including seismic noise, vessel 
noise, and flow noise).
    Given that the effects to marine mammals from the types of surveys 
authorized in this IHA are expected to be limited to low level 
behavioral harassment even in the absence of mitigation, the limited 
additional benefit anticipated by adding this detection method 
(especially for NARWs and other low frequency cetaceans, species for 
which PAM has limited efficacy), and the cost and impracticability of 
implementing a full-time PAM program, we have determined the current 
requirements for visual monitoring are sufficient to ensure the least 
practicable adverse impact on the affected species or stocks and their 
habitat. NMFS has previously provided discussions on why PAM is not a 
required monitoring measure during HRG survey IHAs in past Federal 
Register notices (see 86 FR 21289, April 22, 2021, and 87 FR 13975, 
March 11, 2022, for examples).
    Comment: SELC noted that, subsequent to NMFS' publication of the 
notice of proposed IHA, BOEM made available for public comment eight 
draft WEAs, and that these draft WEAs, and that these draft WEAs 
represent a smaller subset of the BOEM Central Atlantic Call Area that 
formed the basis for TerraSond's planned survey activity. SELC 
expressed concern regarding the potential that TerraSond's planned 
survey activity covers an area larger than the draft WEAs. Relatedly, 
SELC asserted that the same area could be subject to repeated survey 
efforts by different companies (characterizing these hypothetical 
repeated surveys as ``redundant'') and expressed concern regarding the 
potential for cumulative impacts of the activities on NARW.
    Response: We first note that BOEM has not yet finalized its draft 
WEAs following closure of the public comment period on December 16, 
2022. Therefore, it is possible that the draft WEAs may yet be expanded 
to an area more closely approaching the initial Call Area, and NMFS 
cannot make any judgment regarding the need for, or likelihood of, 
TerraSond's proposed survey efforts within the Central Atlantic portion 
of its planned efforts. As noted previously, however, NMFS expects that 
the amount of survey effort ultimately conducted by TerraSond will be 
dictated by commercial interest. As such, NMFS considers it unlikely 
that TerraSond would in fact conduct survey effort over a significantly 
larger area than would be available for wind energy development. 
Regardless, it is not within NMFS' purview to judge the merits of an 
applicant's specified activity. NMFS cannot arbitrarily limit planned 
effort and has no legitimate means of changing the specified activity 
absent a conclusion that the activity would have more than a negligible 
impact. However, NMFS has made the necessary findings under the MMPA 
for issuance of this IHA.
    Regarding the suggestion that future surveys could be conducted 
over the same area by other entities, NMFS declines to speculate as to 
the likelihood that such survey effort may be conducted. Neither the 
MMPA nor NMFS' codified implementing regulations call for consideration 
of other unrelated activities and their impacts on populations. 
Regardless, while NMFS shares the commenter's concerns regarding NARW, 
the potential additional surveys described by SELC cannot at this time 
be considered to be reasonably foreseeable activities.
    Comment: SELC expresses concern regarding what it characterizes as 
inadequate protections for NARW, and reiterates prior recommendations 
for NMFS to reinitiate its 2021 ESA Programmatic Informal Consultation.
    Response: NMFS disagrees with SELC's assertion that existing 
mitigation protections for NARW are inadequate. SELC does not provide 
specific recommendations for requirements that it would deem adequate. 
However, we note that TerraSond is required to implement clearance and 
exclusion zones of 500 m for NARW. This 500 m zone exceeds the modeled 
distance to the largest 160 dB Level B harassment isopleth (141 m 
during sparker use) by a substantial margin. Further, Level A 
harassment (auditory injury) is not expected to result even in the 
absence of mitigation, given the characteristics of the sources planned 
for use. We further note that reinitiation of ESA section 7 
consultation is not warranted, as none of the reinitiation triggers 
listed in NMFS' 2021 programmatic consultation have been met.
    Comment: DNREC recommended that TerraSond consider adopting NMFS' 
proposed changes to the NARW vessel speed rule to further reduce the 
likelihood of vessel collisions.
    Response: As discussed in a previous comment response, NMFS 
requires substantial measures towards minimizing the risk of vessel 
strike and has determined that no vessel strike is anticipated to 
occur.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered

[[Page 31727]]

all of this information, and we refer the reader to these descriptions, 
incorporated here by reference, instead of reprinting the information. 
Additional information regarding population trends and threats may be 
found in NMFS' Stock Assessment Reports (SARs; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species or stocks for which take is expected and 
authorized for this activity, and summarizes information related to the 
population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. PBR is defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS' SARs). While no 
serious injury or mortality is expected to occur, PBR and annual 
serious injury and mortality from anthropogenic sources are included 
here as gross indicators of the status of the species or stocks and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All stocks managed under the MMPA in this region 
are assessed in NMFS' U.S. Atlantic and Gulf of Mexico SARs. All values 
presented in Table 2 are the most recent available at the time of 
publication (draft 2022 SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports.

                                              Table 2--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA  status;  Stock  abundance  (CV,
             Common name                  Scientific name               Stock            strategic  (Y/N)      Nmin, most recent       PBR     Annual  M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
    North Atlantic right whale......  Eubalaena glacialis....  Western North Atlantic   E/D; Y              338 (0; 332; 2020)....        0.7        8.1
                                                                (WNA).
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Gulf of Maine..........  -/-; Y              1,393 (0; 1,380; 2016)         22      12.15
    Minke whale.....................  Balaenoptera             Canadian East Coast....  -/-; N              21,968 (0.31; 17,002;         170       10.6
                                       acutorostrata.                                                        2016).
    Sei whale.......................  Balaenoptera borealis..  Nova Scotia............  E/D; Y              6,292 (1.02; 3,098;           6.2        0.8
                                                                                                             2016).
    Fin whale.......................  Balaenoptera physalus..  WNA....................  E/D; Y              6,802 (0.24; 5,573;            11        1.8
                                                                                                             2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Ziphiidae (beaked whales):
    Cuvier's beaked whale...........  Ziphius cavirostris....  WNA....................  -; N                5,744 (0.36; 4,282;            43        0.2
                                                                                                             2016).
    Mesoplodont beaked whales \5\...  Mesoplodon spp.........  WNA....................  -; N                10,107 (0.27; 8,085;           81        0.4
                                                                                                             2016).
Family Physeteridae:
    Sperm whale.....................  Physeter macrocephalus.  North Atlantic.........  E/D; Y              4,349 (0.28; 3,451;           3.9          0
                                                                                                             2016).
Family Delphinidae:
    Rough-toothed dolphin...........  Steno bredanensis......  WNA....................  -; N                136 (1.0; 67; 2016)...        0.7          0
    Bottlenose dolphin..............  Tursiops truncatus.....  WNA Offshore...........  -/-; N              62,851 (0.23; 51,914;         519         28
                                                                                                             2016).
                                                               WNA Northern Migratory   -/D;Y               6,639 (0.41, 4,759,            48  12.2-21.5
                                                                Coastal.                                     2016).
    Atlantic spotted dolphin........  Stenella frontalis.....  WNA....................  -/-; N              39,921 (0.27; 32,032;         320          0
                                                                                                             2016).
    Common dolphin..................  Delphinus delphis......  WNA....................  -/-; N              172,974 (0.21;              1,452        390
                                                                                                             145,216; 2016).
    Atlantic white-sided dolphin....  Lagenorhynchus acutus..  WNA....................  -/-; N              93,233 (0.71; 54,443;         544         27
                                                                                                             2016).
    Risso's dolphin.................  Grampus griseus........  WNA....................  -/-; N              35,215 (0.19; 30,051;         301         34
                                                                                                             2016).
    Short finned pilot whale........  Globicephala             WNA....................  -/-; N              28,924 (0.24; 23,637;         236        136
                                       macrorhynchus.                                                        2016).
    Long-finned pilot whale.........  G. melas...............  WNA....................  -/-; N              39,215 (0.30; 30,627;         306          9
                                                                                                             2016).
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of     -/-; N              95,543 (0.31; 74,034;         851        164
                                                                Fundy.                                       2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Gray seal \4\...................  Halichoerus grypus.....  WNA....................  -/-; N              27,300 (0.22; 22,785,       1,458      4,452
                                                                                                             2016).
    Harbor seal.....................  Phoca vitulina.........  WNA....................  -/-; N              61,336 (0.08; 57,637,       1,729        339
                                                                                                             2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV
  is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These mortality and serious injury (M/SI) values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from
  all sources combined (e.g., commercial fisheries, ship strike).
\4\ NMFS' stock abundance estimate (and associated PBR value) applies to U.S. population only. Total stock abundance (including animals in Canada) is
  approximately 451,600. The annual M/SI value given is for the total stock.

[[Page 31728]]

 
\5\ Mesoplodont beaked whales in the U.S. Atlantic include the Gervais beaked whale (M. europaeus), Blainville's beaked whale (M. densirostris),
  Sowerby's beaked whale (M. bidens), and True's beaked whale (M. mirus). These species are difficult to identify to the species level at sea;
  therefore, much of the available characterization for beaked whales is to genus level only and the species are managed together as a stock.

    A detailed description of the species likely to be affected by 
TerraSond's activities, including information regarding population 
trends, threats, and local occurrence, was provided in the Federal 
Register notice for the proposed IHA (87 FR 66658; November 4, 2022); 
since that time, we are not aware of any changes in the status of these 
species and stocks; therefore, detailed descriptions are not provided 
here. Please refer to that Federal Register notice for these 
descriptions. Please also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. Marine mammal hearing groups and their 
associated hearing ranges are provided in Table 3.

           Table 3--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
                                                    Generalized hearing
                  Hearing group                           range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales)....  7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, toothed   150 Hz to 160 kHz.
 whales, beaked whales, bottlenose whales).
High-frequency (HF) cetaceans (true porpoises,    275 Hz to 160 kHz.
 Kogia, river dolphins, Cephalorhynchid,
 Lagenorhynchus cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true seals).  50 Hz to 86 kHz.
Otariid pinnipeds (OW) (underwater) (sea lions    60 Hz to 39 kHz.
 and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

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

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the deployed acoustic sources 
have the potential to result in behavioral harassment of marine mammals 
in the vicinity of the study area. The Federal Register notice for the 
proposed IHA (87 FR 66658; November 4, 2022) included a discussion of 
the effects of anthropogenic noise on marine mammals and their habitat, 
therefore that information is not repeated here; please refer to the 
Federal Register notice for that information.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, which will inform both NMFS' consideration 
of ``small numbers,'' and the negligible impact determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes are by Level B harassment only, in the form of 
disruption of behavioral patterns for individual marine mammals 
resulting from exposure to sound produced by the sparker. Based 
primarily on the characteristics of the signals produced by the 
acoustic sources planned for use, Level A harassment is neither 
anticipated (even absent mitigation), nor authorized. Consideration of 
the anticipated effectiveness of the mitigation measures (i.e., 
shutdown zones and shutdown measures), discussed in detail below in the 
Mitigation section, further strengthens the conclusion that Level A 
harassment is not a reasonably anticipated outcome of the survey 
activity. As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
take numbers are estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas;

[[Page 31729]]

and, (4) the number of days of activities. We note that while these 
factors can contribute to a basic calculation to provide an initial 
prediction of potential takes, additional information that can 
qualitatively inform take estimates is also sometimes available (e.g., 
previous monitoring results or average group size). Below, we describe 
the factors considered here in more detail and present the take 
estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 160 dB (re 1 [mu]Pa) 
for impulsive (e.g., seismic airguns) or intermittent (e.g., scientific 
sonar) sources. Generally speaking, Level B harassment take estimates 
based on these behavioral harassment thresholds are expected to include 
any likely takes by temporary threshold shift (TTS) as, in most cases, 
the likelihood of TTS occurs at distances from the source less than 
those at which behavioral harassment is likely. TTS of a sufficient 
degree can manifest as behavioral harassment, as reduced hearing 
sensitivity and the potential reduced opportunities to detect important 
signals (conspecific communication, predators, prey) may result in 
changes in behavior patterns that would not otherwise occur.
    TerraSond's planned activity includes the use of impulsive 
(sparker) sources, and therefore the RMS SPL threshold of 160 dB re 1 
[mu]Pa is applicable.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). The 
references, analysis, and methodology used in the development of the 
thresholds are described in NMFS' 2018 Technical Guidance, which may be 
accessed at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    TerraSond's planned activity includes the use of impulsive (i.e., 
sparkers) sources. However, as discussed above, NMFS has concluded that 
Level A harassment is not a reasonably likely outcome for marine 
mammals exposed to noise through use of the sources planned for use 
here, and the potential for Level A harassment is not evaluated further 
in this document. Please see TerraSond's application for details of a 
quantitative exposure analysis exercise, i.e., calculated Level A 
harassment isopleths and estimated Level A harassment exposures. 
TerraSond did not request authorization of take by Level A harassment, 
and no take by Level A harassment is authorized by NMFS.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    NMFS has developed a user-friendly methodology for estimating the 
extent of the Level B harassment isopleths associated with relevant HRG 
survey equipment (NMFS, 2020). This methodology incorporates frequency 
and directionality (when relevant) to refine estimated ensonified 
zones. For acoustic sources that operate with different beamwidths, the 
maximum beamwidth is used, and the lowest frequency of the source is 
used when calculating the frequency-dependent absorption coefficient 
(Table 1). The sparkers planned for use by TerraSond are 
omnidirectional and, therefore, beamwidth does not factor into the 
calculations.
    NMFS considers the data provided by Crocker and Fratantonio (2016) 
to represent the best available information on source levels associated 
with HRG equipment and, therefore, recommends that source levels 
provided by Crocker and Fratantonio (2016) be incorporated in the 
method described above to estimate isopleth distances to harassment 
thresholds. In cases when the source level for a specific type of HRG 
equipment is not provided in Crocker and Fratantonio (2016), NMFS 
recommends that either the source levels provided by the manufacturer 
be used, or, in instances where source levels provided by the 
manufacturer are unavailable or unreliable, a proxy from Crocker and 
Fratantonio (2016) be used instead. Table 1 provides relevant source 
parameters used in the calculations. Results of modeling using the 
methodology described above produced an estimated Level B harassment 
isopleth of 141 m.
    Central Atlantic--Phase 1, Alternative 1 would involve a single 
towed source, and daily ensonified area was calculated as follows: (100 
km x 2 x 0.141 km) + ([pi] x (0.141\2\ km). Distributing the 58,607 km 
of Phase 1, Alternative 1 survey activity across the 12-month period of 
anticipated activity results in approximately 48.8 survey days per 
month, which was multiplied by the daily ensonified area to give a 
monthly ensonified area of 1,380 km. Phase 1, Alternative 2 would 
involve three towed sources with 150 m horizontal separation between 
them. Daily ensonified area was calculated as follows: (100 km x 2 x 
(0.141 km + 0.15 km) + ([pi] x (0.291\2\ km). Distributing the 19,536 
km of Phase 1, Alternative 2 survey activity across the 12-month period 
of anticipated activity results in approximately 16.3 survey days per 
month, which was multiplied by the daily ensonified area to give a 
monthly ensonified area of 952 km\2\. Because only one of the 
alternatives would ultimately be selected, the monthly ensonified area 
associated with Alternative 1 was used to estimate potential marine 
mammal take for Phase 1.
    Phase 2 involves two towed sources with 30 m horizontal separation 
between them. Daily ensonified area was calculated as follows: (100 km 
x 2 x (0.141 km + 0.015 km) + ([pi] x (0.156\2\ km). Distributing the 
46,573 km of Phase 2 survey activity across the 12-month period of 
anticipated activity results in approximately 38.8 survey days per 
month, which was multiplied

[[Page 31730]]

by the daily ensonified area to give a monthly ensonified area of 1,214 
km\2\.
    New York Bight--Phase 1 involves a single towed source, and 
ensonified area was calculated in the same manner as described above 
for Central Atlantic Phase 1, Alternative 1. Distributing the 14,833 km 
of Phase 1 survey activity across the 12-month period of anticipated 
activity results in approximately 12.4 survey days per month, which was 
multiplied by the daily ensonified area to give a monthly ensonified 
area of 349 km\2\. Phases 2 and 3 each use a dual source configuration 
with a horizontal separation distance of 30 m between the sources, and 
ensonified area was calculated in the same manner as described above 
for Central Atlantic Phase 2. For Phase 2, TerraSond assumes that there 
would be two days of survey activity, giving a total ensonified area of 
62.6 km\2\. Distributing the combined 23,311 km of Phase 3 survey 
activity across the 12-month period of anticipated activity results in 
approximately 19.4 survey days per month, which was multiplied by the 
daily ensonified area to give a monthly ensonified area of 608 km\2\.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information, that 
will inform the take calculations.
    Habitat-based density models produced by the Duke University Marine 
Geospatial Ecology Laboratory (Roberts and Halpin, 2022) represent the 
best available information regarding marine mammal densities in the 
survey area. These density data incorporate aerial and shipboard line-
transect survey data from NMFS and other organizations and incorporate 
data from numerous physiographic and dynamic oceanographic and 
biological covariates, and control for the influence of sea state, 
group size, availability bias, and perception bias on the probability 
of making a sighting. These density models were originally developed 
for all cetacean taxa in the U.S. Atlantic (Roberts et al., 2016). In 
subsequent years, the models have been updated based on additional data 
as well as certain methodological improvements. More information is 
available online at https://seamap.env.duke.edu/models/Duke/EC/. Marine 
mammal density estimates in the survey area (animals/km\2\) were 
obtained using the most recent model results for all taxa.
    In order to select a representative sample of grid cells in and 
near each survey area, TerraSond created a 10-km wide perimeter around 
each area (Figures 1 and 2) in a Geographic Information System (GIS). 
The perimeter was then used to select grid cells in and around each 
area containing the monthly or annual estimates for each species. The 
average monthly abundance for each species in each area was calculated 
as the mean value of the selected grid cells in each month. See Tables 
10 and 11 in TerraSond's application for density values used in the 
analysis.
    Density information is presented for seals generically. In order to 
generate species-specific density values, TerraSond multiplied seal 
density values by the proportion of total SAR-estimated seal abundance 
attributed to each species. Roberts and Halpin (2022) similarly provide 
generic density information for pilot whales and bottlenose dolphins. 
In the Central Atlantic survey area, where both species of pilot whales 
could be encountered, TerraSond requested that the density-based take 
estimate be divided equally across the two species. In the New York 
Bight survey area, only the long-finned pilot whale is expected to be 
present, and all estimated takes are attributed to that species. For 
bottlenose dolphins, although the northern coastal migratory stock 
could be present in the region, all survey effort is in sufficiently 
deep water (20-65 m) that we assume all potential bottlenose dolphin 
takes are appropriately assigned to the offshore stock.

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and is authorized.
    Estimates of the potential number of takes by Level B harassment 
were calculated by multiplying the monthly density for each species in 
the respective survey areas (Central Atlantic and New York Bight) by 
the respective monthly ensonified area for each Phase and then summing 
across the 12 months. TerraSond evaluated monitoring reports from the 
vicinity of the survey areas, finding that the common dolphin estimated 
take number for the New York Bight survey area may be underestimated. 
Based on these observational data, TerraSond assumes that 16 common 
dolphins may be encountered within the harassment zone on each survey 
data. Based on the planned 385 survey days in the New York Bight survey 
area, this produces an estimate of 6,160 takes. This larger value is 
substituted for the density-based take estimate for common dolphins. 
Table 4 provides information about the take estimates and authorized 
take.

                                                Table 4--Estimated Take Numbers and Total Authorized Take
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Estimated take-- Central     Estimated take-- New York bight
                                                                 Atlantic         ---------------------------------------   Authorized        Percent
                        Species                         --------------------------                                             take          abundance
                                                           Phase 1      Phase 2      Phase 1      Phase 2      Phase 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale.............................          5.1          4.5          1.9          0.0          3.3              15             4.4
Humpback whale.........................................         21.6         19.0          4.0          0.1          7.0              52             3.7
Minke whale............................................         30.7         27.0         14.7          0.2         25.5              98             0.4
Sei whale..............................................          4.9          4.3          1.2          0.0          2.2              13             0.2
Fin whale..............................................         44.1         38.8          8.0          0.1         14.0             105             1.5
Cuvier's beaked whale..................................         29.1         25.6            0            0            0              55             1.0
Mesoplodont beaked whales..............................          5.7          5.0            0            0            0              11             0.1
Sperm whale............................................         16.0         14.1          0.6            0          1.1              32             0.7
Rough-toothed dolphin \1\..............................          2.0          1.6            0            0            0              10             7.4
Bottlenose dolphin.....................................      1,427.7      1,255.6        116.6          1.8        202.8           3,005             4.8
Atlantic spotted dolphin...............................        605.6        532.6         20.9          0.3         36.3           1,196             3.0
Common dolphin \2\.....................................      5,097.1      4,482.4        597.5          8.9      1,039.1          11,225             6.5
Atlantic white-sided dolphin...........................        117.6        103.4         45.1          0.7         78.4             345             0.4
Risso's dolphin........................................        171.9        151.2          5.7          0.1          9.9             339             1.0
Short-finned pilot whale...............................        238.8        210.1            0            0            0             449             1.6
Long-finned pilot whale................................        238.9        210.0         11.1          0.2         19.3             480             1.2
Harbor porpoise........................................        124.0        109.1        102.1          1.5        177.6             514             0.5
Gray seal..............................................        439.7        386.7         60.6          0.9        105.4             993             0.2

[[Page 31731]]

 
Harbor seal............................................        237.5        208.9        136.2          2.0        236.9             822             1.3
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ For rough-toothed dolphin, we authorize take in the form of one encounter with a group of average size, as assumed average group size (10) is larger
  than the total estimated take number (4). Mean group sizes were calculated from regional sightings data (Whitt et al., 2015; Kraus et al., 2016; Palka
  et al., 2017).
\2\ For common dolphin, estimated take numbers for the New York Bight survey area were calculated based on an assumption (based on monitoring data from
  the area) that 16 dolphins per day could be encountered within the harassment zone. These values were larger than and used instead of the results of
  density-based calculations.

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, as 
well as subsistence uses. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope, range). It further 
considers the likelihood that the measure will be effective if 
implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, and impact on 
operations.
    NMFS requires that the following mitigation measures be implemented 
during TerraSond's planned marine site characterization surveys. 
Pursuant to section 7 of the ESA, TerraSond is also required to adhere 
to relevant Project Design Criteria (PDC) of the NMFS' Greater Atlantic 
Regional Fisheries Office (GARFO) programmatic consultation 
(specifically PDCs 4, 5, and 7) regarding geophysical surveys along the 
U.S. Atlantic coast (www.fisheries.noaa.gov/new-england-mid-atlantic/consultations/section-7-take-reporting-programmatics-greater-atlantic#offshore-wind-site-assessment-and-site-characterization-activities-programmatic-consultation).

Visual Monitoring and Shutdown Zones

    During survey operations (e.g., any day on which use of the sparker 
source is planned to occur, and whenever the sparker source is in the 
water, whether activated or not), a minimum of one visual PSO must be 
on duty on each source vessel and conducting visual observations at all 
times during daylight hours (i.e., from 30 minutes prior to sunrise 
through 30 minutes following sunset). A minimum of two PSOs must be on 
duty on each source vessel during nighttime hours. Visual monitoring 
must begin no less than 30 minutes prior to ramp-up (described below) 
and must continue until one hour after use of the sparker source 
ceases.
    Visual PSOs shall coordinate to ensure 360[deg] visual coverage 
around the vessel from the most appropriate observation posts and shall 
conduct visual observations using binoculars and the naked eye while 
free from distractions and in a consistent, systematic, and diligent 
manner. PSOs shall establish and monitor applicable shutdown zones (see 
below). These zones shall be based upon the radial distance from the 
sparker source (rather than being based around the vessel itself).
    Two shutdown zones are defined, depending on the species and 
context. Here, an extended shutdown zone encompassing the area at and 
below the sea surface out to a radius of 500 m from the sparker source 
(0-500 m) is defined for NARWs. For all other marine mammals, the 
shutdown zone encompasses a standard distance of 100 m (0-100 m). Any 
observations of marine mammals by crew members aboard any vessel 
associated with the survey shall be relayed to the PSO team.
    Visual PSOs may be on watch for a maximum of four consecutive hours 
followed by a break of at least one hour between watches and may 
conduct a maximum of 12 hours of observation per 24-hr period.

Pre-Start Clearance and Ramp-Up

    A ramp-up procedure, involving a gradual increase in source level 
output, is required at all times as part of the activation of the 
sparker source when technically feasible. Operators should ramp up 
sparkers to half power for 5 minutes and then proceed to full power. A 
30-minute pre-start clearance observation period must occur prior to 
the start of ramp-up. The intent of pre-start clearance observation (30 
minutes) is to ensure no marine mammals are within the shutdown zones 
prior to the beginning of ramp-up. The intent of ramp-up is to warn 
marine mammals of pending operations and to allow sufficient time for 
those animals to leave the immediate vicinity. All operators must 
adhere to the following pre-start clearance and ramp-up requirements:
     The operator must notify a designated PSO of the planned 
start of ramp-up as agreed upon with the lead PSO; the notification 
time should not be less than 60 minutes prior to the planned ramp-up in 
order to allow the PSOs time to monitor the shutdown zones for 30 
minutes prior to the initiation of ramp-up (pre-start clearance). 
During this 30 minute pre-start clearance period the entire shutdown 
zone must be visible, except as indicated below.
     Ramp-ups shall be scheduled so as to minimize the time 
spent with the source activated.
     A visual PSO conducting pre-start clearance observations 
must be notified again immediately prior to initiating ramp-up 
procedures and the operator must receive confirmation from the PSO to 
proceed.
     Any PSO on duty has the authority to delay the start of 
survey operations if a marine mammal is detected within the applicable 
pre-start clearance zone.

[[Page 31732]]

     The operator must establish and maintain clear lines of 
communication directly between PSOs on duty and crew controlling the 
acoustic source to ensure that mitigation commands are conveyed swiftly 
while allowing PSOs to maintain watch.
     The pre-start clearance requirement is waived for small 
delphinids and pinnipeds. Detection of a small delphinid (individual 
belonging to the following genera of the Family Delphinidae: Steno, 
Delphinus, Lagenorhynchus, Stenella, and Tursiops) or pinniped within 
the shutdown zone does not preclude beginning of ramp-up, unless the 
PSO confirms the individual to be of a genus other than those listed, 
in which case normal pre-clearance requirements apply.
     If there is uncertainty regarding identification of a 
marine mammal species (i.e., whether the observed marine mammal(s) 
belongs to one of the delphinid genera for which the pre-clearance 
requirement is waived), PSOs may use best professional judgment in 
making the decision to call for a shutdown.
     Ramp-up may not be initiated if any marine mammal to which 
the pre-start clearance requirement applies is within the shutdown 
zone. If a marine mammal is observed within the shutdown zone during 
the 30 minute pre-start clearance period, ramp-up may not begin until 
the animal(s) has been observed exiting the zones or until an 
additional time period has elapsed with no further sightings (30 
minutes for all baleen whale species and sperm whales and 15 minutes 
for all other species).
     PSOs must monitor the shutdown zones 30 minutes before and 
during ramp-up, and ramp-up must cease and the source must be shut down 
upon observation of a marine mammal within the applicable shutdown 
zone.
     Ramp-up may occur at times of poor visibility, including 
nighttime, if appropriate visual monitoring has occurred with no 
detections of marine mammals in the 30 minutes prior to beginning ramp-
up. Sparker activation may only occur at night where operational 
planning cannot reasonably avoid such circumstances.
     If the acoustic source is shut down for brief periods 
(i.e., less than 30 minutes) for reasons other than implementation of 
prescribed mitigation (e.g., mechanical difficulty), it may be 
activated again without ramp-up if PSOs have maintained constant visual 
observation and no detections of marine mammals have occurred within 
the applicable shutdown zone. For any longer shutdown, pre-start 
clearance observation and ramp-up are required.

Shutdown

    All operators must adhere to the following shutdown requirements:
     Any PSO on duty has the authority to call for shutdown of 
the sparker source if a marine mammal is detected within the applicable 
shutdown zone.
     The operator must establish and maintain clear lines of 
communication directly between PSOs on duty and crew controlling the 
source to ensure that shutdown commands are conveyed swiftly while 
allowing PSOs to maintain watch.
     When the sparker source is active and a marine mammal 
appears within or enters the applicable shutdown zone, the source must 
be shut down. When shutdown is instructed by a PSO, the source must be 
immediately deactivated and any dispute resolved only following 
deactivation.
     The shutdown requirement is waived for small delphinids 
and pinnipeds. If a small delphinid (individual belonging to the 
following genera of the Family Delphinidae: Steno, Delphinus, 
Lagenorhynchus, Stenella, and Tursiops) or pinniped is visually 
detected within the shutdown zone, no shutdown is required unless the 
PSO confirms the individual to be of a genus other than those listed, 
in which case a shutdown is required.
     If there is uncertainty regarding identification of a 
marine mammal species (i.e., whether the observed marine mammal(s) 
belongs to one of the delphinid genera for which shutdown is waived or 
one of the species with a larger shutdown zone), PSOs may use best 
professional judgment in making the decision to call for a shutdown.
     Upon implementation of shutdown, the source may be 
reactivated after the marine mammal has been observed exiting the 
applicable shutdown zone or following a clearance period (30 minutes 
for all baleen whale species and sperm whales and 15 minutes for all 
other species) with no further detection of the marine mammal.
    If a species for which authorization has not been granted, or a 
species for which authorization has been granted but the authorized 
number of takes have been met, approaches or is observed within the 
Level B harassment zone, shutdown would occur.

Vessel Strike Avoidance

    Crew and supply vessel personnel should use an appropriate 
reference guide that includes identifying information on all marine 
mammals that may be encountered. Vessel operators must comply with the 
below measures except under extraordinary circumstances when the safety 
of the vessel or crew is in doubt or the safety of life at sea is in 
question. These requirements do not apply in any case where compliance 
would create an imminent and serious threat to a person or vessel or to 
the extent that a vessel is restricted in its ability to maneuver and, 
because of the restriction, cannot comply.
     Vessel operators and crews must maintain a vigilant watch 
for all marine mammals and slow down, stop their vessel, or alter 
course, as appropriate and regardless of vessel size, to avoid striking 
any marine mammal. A single marine mammal at the surface may indicate 
the presence of submerged animals in the vicinity of the vessel; 
therefore, precautionary measures should always be exercised. A visual 
observer aboard the vessel must monitor a vessel strike avoidance zone 
around the vessel (species-specific distances detailed below). Visual 
observers monitoring the vessel strike avoidance zone may be third-
party observers (i.e., PSOs) or crew members, but crew members 
responsible for these duties must be provided sufficient training to: 
(1) distinguish marine mammal from other phenomena and (2) broadly to 
identify a marine mammal as a right whale, other whale (defined in this 
context as sperm whales or baleen whales other than right whales), or 
other marine mammals.
     All vessels, regardless of size, must observe a 10-kn 
speed restriction in specific areas designated by NMFS for the 
protection of North Atlantic right whales from vessel strikes. These 
include all Seasonal Management Areas (SMA) (when in effect), any 
dynamic management areas (DMA) (when in effect), and Slow Zones. See 
www.fisheries.noaa.gov/national/endangered-species-conservation/reducing-ship-strikes-north-atlantic-right-whales for specific detail 
regarding these areas.
     Vessel speeds must also be reduced to 10 kn or less when 
mother/calf pairs, pods, or large assemblages of cetaceans are observed 
near a vessel.
     All vessels must maintain a minimum separation distance of 
500 m from right whales. If a right whale is sighted within the 
relevant separation distance, the vessel must steer a course away at 10 
kn or less until the 500-m separation distance has been established. If 
a whale is observed but cannot be confirmed as a species other than a 
right whale, the vessel operator must assume that it is a right whale 
and take appropriate action.

[[Page 31733]]

     All vessels must maintain a minimum separation distance of 
100 m from sperm whales and all other baleen whales.
     All vessels must, to the maximum extent practicable, 
attempt to maintain a minimum separation distance of 50 m from all 
other marine mammals, with an understanding that at times this may not 
be possible (e.g., for animals that approach the vessel).
     When marine mammals are sighted while a vessel is 
underway, the vessel shall take action as necessary to avoid violating 
the relevant separation distance (e.g., attempt to remain parallel to 
the animal's course, avoid excessive speed or abrupt changes in 
direction until the animal has left the area, reduce speed and shift 
the engine to neutral). This does not apply to any vessel towing gear 
or any vessel that is navigationally constrained.
    Members of the PSO team will consult NMFS' North Atlantic right 
whale reporting system and Whale Alert, daily and as able, for the 
presence of NARWs throughout survey operations, and for the 
establishment of DMAs and/or Slow Zones. It is TerraSond's 
responsibility to maintain awareness of the establishment and location 
of any such areas and to abide by these requirements accordingly.
    Based on our evaluation of the required measures, as well as other 
measures considered by NMFS, NMFS has determined that the mitigation 
measures provide the means of effecting the least practicable impact on 
the affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     Mitigation and monitoring effectiveness.
    TerraSond must use independent, dedicated, trained PSOs, meaning 
that the PSOs must be employed by a third-party observer provider, must 
have no tasks other than to conduct observational effort, collect data, 
and communicate with and instruct relevant vessel crew with regard to 
the presence of marine mammal and mitigation requirements (including 
brief alerts regarding maritime hazards), and must have successfully 
completed an approved PSO training course for geophysical surveys. 
Visual monitoring must be performed by qualified, NMFS-approved PSOs. 
PSO resumes must be provided to NMFS for review and approval prior to 
the start of survey activities.
    PSO names must be provided to NMFS by the operator for review and 
confirmation of their approval for specific roles prior to commencement 
of the survey. For prospective PSOs not previously approved, or for 
PSOs whose approval is not current, NMFS must review and approve PSO 
qualifications. Resumes should include information related to relevant 
education, experience, and training, including dates, duration, 
location, and description of prior PSO experience. Resumes must be 
accompanied by relevant documentation of successful completion of 
necessary training.
    NMFS may approve PSOs as conditional or unconditional. A 
conditionally-approved PSO may be one who is trained but has not yet 
attained the requisite experience. An unconditionally-approved PSO is 
one who has attained the necessary experience. For unconditional 
approval, the PSO must have a minimum of 90 days at sea performing the 
role during a geophysical survey, with the conclusion of the most 
recent relevant experience not more than 18 months previous.
    At least one of the visual PSOs aboard the vessel must be 
unconditionally-approved. One unconditionally-approved visual PSO shall 
be designated as the lead for the entire PSO team. This lead should 
typically be the PSO with the most experience, who would coordinate 
duty schedules and roles for the PSO team and serve as primary point of 
contact for the vessel operator. To the maximum extent practicable, the 
duty schedule shall be planned such that unconditionally-approved PSOs 
are on duty with conditionally-approved PSOs.
    PSOs must successfully complete relevant training, including 
completion of all required coursework and passing (80 percent or 
greater) a written and/or oral examination developed for the training 
program.
    PSOs must have successfully attained a bachelor's degree from an 
accredited college or university with a major in one of the natural 
sciences, a minimum of 30 semester hours or equivalent in the 
biological sciences, and at least one undergraduate course in math or 
statistics. The educational requirements may be waived if the PSO has 
acquired the relevant skills through alternate experience. Requests for 
such a waiver shall be submitted to NMFS and must include written 
justification. Alternate experience that may be considered includes, 
but is not limited to (1) secondary education and/or experience 
comparable to PSO duties; (2) previous work experience conducting 
academic, commercial, or government-sponsored marine mammal surveys; 
and (3) previous work experience as a PSO (PSO must be in good standing 
and demonstrate good performance of PSO duties).
    TerraSond must work with the selected third-party PSO provider to 
ensure PSOs have all equipment (including backup equipment) needed to 
adequately perform necessary tasks, including accurate determination of 
distance and bearing to observed marine

[[Page 31734]]

mammals, and to ensure that PSOs are capable of calibrating equipment 
as necessary for accurate distance estimates and species 
identification. Such equipment, at a minimum, shall include:
     At least one thermal (infrared) imagine device suited for 
the marine environment;
     Reticle binoculars (e.g., 7 x 50) of appropriate quality 
(at least one per PSO, plus backups);
     Global Positioning Units (GPS) (at least one plus 
backups);
     Digital cameras with a telephoto lens that is at least 
300-mm or equivalent on a full-frame single lens reflex (SLR) (at least 
one plus backups). The camera or lens should also have an image 
stabilization system;
     Equipment necessary for accurate measurement of distances 
to marine mammal;
     Compasses (at least one plus backups);
     Means of communication among vessel crew and PSOs; and
     Any other tools deemed necessary to adequately and 
effectively perform PSO tasks.
    The equipment specified above may be provided by an individual PSO, 
the third-party PSO provider, or the operator, but TerraSond is 
responsible for ensuring PSOs have the proper equipment required to 
perform the duties specified in the IHA.
    The PSOs will be responsible for monitoring the waters surrounding 
the survey vessel to the farthest extent permitted by sighting 
conditions, including shutdown zones, during all HRG survey operations. 
PSOs will visually monitor and identify marine mammals, including those 
approaching or entering the established shutdown zones during survey 
activities. It will be the responsibility of the PSO(s) on duty to 
communicate the presence of marine mammals as well as to communicate 
the action(s) that are necessary to ensure mitigation and monitoring 
requirements are implemented as appropriate.
    PSOs must be equipped with binoculars and have the ability to 
estimate distance and bearing to detect marine mammals, particularly in 
proximity to shutdown zones. Reticulated binoculars must also be 
available to PSOs for use as appropriate based on conditions and 
visibility to support the sighting and monitoring of marine mammals. 
During nighttime operations, night-vision goggles with thermal clip-ons 
and infrared technology must be available for use. Position data would 
be recorded using hand-held or vessel GPS units for each sighting.
    During good conditions (e.g., daylight hours; Beaufort sea state 
(BSS) 3 or less), to the maximum extent practicable, PSOs should also 
conduct observations when the acoustic source is not operating for 
comparison of sighting rates and behavior with and without use of the 
active acoustic sources. Any observations of marine mammals by crew 
members aboard the vessel associated with the survey would be relayed 
to the PSO team.
    Data on all PSO observations would be recorded based on standard 
PSO collection requirements (see Reporting Measures). This would 
include dates, times, and locations of survey operations; dates and 
times of observations, location and weather; details of marine mammal 
sightings (e.g., species, numbers, behavior); and details of any 
observed marine mammal behavior that occurs (e.g., noted behavioral 
disturbances).

Reporting Measures

    TerraSond shall submit a draft summary report on all activities and 
monitoring results within 90 days of the completion of the survey or 
expiration of the IHA, whichever comes sooner. The report must describe 
all activities conducted and sightings of marine mammals, must provide 
full documentation of methods, results, and interpretation pertaining 
to all monitoring, and must summarize the dates and locations of survey 
operations and all marine mammals sightings (dates, times, locations, 
activities, associated survey activities). The draft report shall also 
include geo-referenced, time-stamped vessel tracklines for all time 
periods during which acoustic sources were operating. Tracklines should 
include points recording any change in acoustic source status (e.g., 
when the sources began operating, when they were turned off, or when 
they changed operational status such as from full array to single gun 
or vice versa). GIS files shall be provided in ESRI shapefile format 
and include the UTC date and time, latitude in decimal degrees, and 
longitude in decimal degrees. All coordinates shall be referenced to 
the WGS84 geographic coordinate system. In addition to the report, all 
raw observational data shall be made available. The report must 
summarize the information. A final report must be submitted within 30 
days following resolution of any comments on the draft report. All 
draft and final marine mammal monitoring reports must be submitted to 
[email protected] and [email protected].
    PSOs must use standardized electronic data forms to record data. 
PSOs shall record detailed information about any implementation of 
mitigation requirements, including the distance of marine mammal to the 
acoustic source and description of specific actions that ensued, the 
behavior of the animal(s), any observed changes in behavior before and 
after implementation of mitigation, and if shutdown was implemented, 
the length of time before any subsequent ramp-up of the acoustic 
source. If required mitigation was not implemented, PSOs should record 
a description of the circumstances. At a minimum, the following 
information must be recorded:
    1. Vessel name (source vessel), vessel size and type, maximum speed 
capability of vessel;
    2. Dates of departures and returns to port with port name;
    3. PSO names and affiliations;
    4. Date and participants of PSO briefings;
    5. Visual monitoring equipment used;
    6. PSO location on vessel and height of observation location above 
water surface;
    7. Dates and times (Greenwich Mean Time) of survey on/off effort 
and times corresponding with PSO on/off effort;
    8. Vessel location (decimal degrees) when survey effort begins and 
ends and vessel location at beginning and end of visual PSO duty 
shifts;
    9. Vessel location at 30-second intervals if obtainable from data 
collection software, otherwise at practical regular interval
    10. Vessel heading and speed at beginning and end of visual PSO 
duty shifts and upon any change;
    11. Water depth (if obtainable from data collection software);
    12. Environmental conditions while on visual survey (at beginning 
and end of PSO shift and whenever conditions change significantly), 
including BSS and any other relevant weather conditions including cloud 
cover, fog, sun glare, and overall visibility to the horizon;
    13. Factors that may contribute to impaired observations during 
each PSO shift change or as needed as environmental conditions change 
(e.g., vessel traffic, equipment malfunctions); and
    14. Survey activity information (and changes thereof), such as 
acoustic source power output while in operation, number and volume of 
airguns operating in an array, tow depth of an acoustic source, and any 
other notes of significance (i.e., pre-start clearance, ramp-up, 
shutdown, testing, shooting,

[[Page 31735]]

ramp-up completion, end of operations, streamers, etc.).
    15. Upon visual observation of any marine mammal, the following 
information must be recorded:
    a. Watch status (sighting made by PSO on/off effort, opportunistic, 
crew, alternate vessel/platform);
    b. Vessel/survey activity at time of sighting (e.g., deploying, 
recovering, testing, shooting, data acquisition, other);
    c. PSO who sighted the animal;
    d. Time of sighting;
    e. Initial detection method;
    f. Sightings cue;
    g. Vessel location at time of sighting (decimal degrees);
    h. Direction of vessel's travel (compass direction);
    i. Speed of the vessel(s) from which the observation was made;
    j. Identification of the animal (e.g., genus/species, lowest 
possible taxonomic level or unidentified); also note the composition of 
the group if there is a mix of species;
    k. Species reliability (an indicator of confidence in 
identification);
    l. Estimated distance to the animal and method of estimating 
distance;
    m. Estimated number of animals (high/low/best);
    n. Estimated number of animals by cohort (adults, yearlings, 
juveniles, calves, group composition, etc.);
    o. Description (as many distinguishing features as possible of each 
individual seen, including length, shape, color, pattern, scars, or 
markings, shape and size of dorsal fin, shape of head, and blow 
characteristics);
    p. Detailed behavior observations (e.g., number of blows/breaths, 
number of surfaces, breaching, spyhopping, diving, feeding, traveling; 
as explicit and detailed as possible; note any observed changes in 
behavior before and after point of closest approach);
    q. Mitigation actions; description of any actions implemented in 
response to the sighting (e.g., delays, shutdowns, ramp-up, speed or 
course alteration, etc.) and time and location of the action;
    r. Equipment operating during sighting;
    s. Animal's closest point of approach and/or closest distance from 
the center point of the acoustic source; and
    t. Description of any actions implemented in response to the 
sighting (e.g., delays, shutdown, ramp-up) and time and location of the 
action.
    If a NARW is observed at any time by PSOs or personnel on the 
project vessel, during surveys or during vessel transit, TerraSond must 
report the sighting information to the NMFS North Atlantic Right Whale 
Sighting Advisory System (866-755-6622) within 2 hours of occurrence, 
when practicable, or no later than 24 hours after occurrence. North 
Atlantic right whale sightings in any location may also be reported to 
the U.S. Coast Guard via channel 16 and through the WhaleAlert app 
(www.whalealert.org).
    In the event that personnel involved in the survey activities 
discover an injured or dead marine mammal, the incident must be 
reported to NMFS as soon as feasible by phone (866-755-6622) and by 
email ([email protected] and 
[email protected]). The report must include the 
following information:
    1. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    2. Species identification (if known) or description of the 
animal(s) involved;
    3. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    4. Observed behaviors of the animal(s), if alive;
    5. If available, photographs or video footage of the animal(s); and
    6. General circumstances under which the animal was discovered.
    In the event of a ship strike of a marine mammal by any vessel 
involved in the activities, TerraSond must report the incident to NMFS 
by phone (866-755-6622) and by email ([email protected] 
and [email protected]) as soon as feasible. The report 
must include the following information:
    1. Time, date, and location (latitude/longitude) of the incident;
    2. Species identification (if known) or description of the 
animal(s) involved;
    3. Vessel's speed during and leading up to the incident;
    4. Vessel's course/heading and what operations were being conducted 
(if applicable);
    5. Status of all sound sources in use;
    6. Description of avoidance measures/requirements that were in 
place at the time of the strike and what additional measures were 
taken, if any, to avoid strike;
    7. Environmental conditions (e.g., wind speed and direction, BSS, 
cloud cover, visibility) immediately preceding the strike;
    8. Estimated size and length of animal that was struck;
    9. Description of the behavior of the marine mammal immediately 
preceding and/or following the strike;
    10. If available, description of the presence and behavior of any 
other marine mammals immediately preceding the strike;
    11. Estimated fate of the animal (e.g., dead, injured but alive, 
injured and moving, blood or tissue observed in the water, status 
unknown, disappeared); and
    12. To the extent practicable, photographs or video footage of the 
animal(s).

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the majority of our analysis applies to all 
the species listed in Table 2, given that the anticipated effects of 
this project on different marine mammal stocks are expected to be 
relatively similar in nature. Where there are meaningful differences 
between species or stocks, or groups of species, in anticipated 
individual responses to activities, impact of expected take on the 
population due to differences in population status, or impacts on 
habitat, they are included as a separate sub-sections. Specifically, we 
provide additional discussion related to NARWs and to other species 
currently

[[Page 31736]]

experiencing unusual mortality events (UME).
    NMFS does not anticipate that serious injury or mortality would 
occur as a result of HRG surveys, even in the absence of mitigation, 
and no serious injury or mortality is authorized. As discussed in the 
Potential Effects of Specified Activities on Marine Mammals and their 
Habitat section of the proposed Federal Register notice (87 FR 66658, 
November 4, 2022), non-auditory physical effects and vessel strike are 
not expected to occur. NMFS expects that all potential takes would be 
in the form of short-term Level B behavioral harassment, e.g., 
temporary avoidance of the area or decreased foraging (if such activity 
was occurring), reactions that are considered to be of low severity and 
with no lasting biological consequences (e.g., Southall et al., 2007, 
Ellison et al., 2012). As described above, Level A harassment is not 
expected to occur given the nature of the operations, the estimated 
size of the Level A harassment zones, and the required shutdown zones 
for certain activities.
    In addition to being temporary, the maximum expected harassment 
zone around a survey vessel is 141 m. Therefore, the ensonified area 
surrounding each vessel is relatively small compared to the overall 
distribution of the animals in the area and their use of the habitat. 
Feeding behavior is not likely to be significantly impacted as prey 
species are mobile and are broadly distributed throughout the survey 
area; therefore, marine mammals that may be temporarily displaced 
during survey activities are expected to be able to resume foraging 
once they have moved away from areas with disturbing levels of 
underwater noise. Because of the temporary nature of the disturbance 
and the availability of similar habitat and resources in the 
surrounding area, the impacts to marine mammals and the food sources 
that they utilize are not expected to cause significant or long-term 
consequences for individual marine mammals or their populations.
    There are no rookeries, mating or calving grounds known to be 
biologically important to marine mammals within the survey area and 
there are no feeding areas known to be biologically important to marine 
mammals within the survey area. There is no designated critical habitat 
for any ESA-listed marine mammals in the survey area.

North Atlantic Right Whales

    The status of the NARW population is of heightened concern and, 
therefore, merits additional analysis. As noted previously, elevated 
NARW mortalities began in 2017 and there is an active UME. Overall, 
preliminary findings support human interactions, specifically vessel 
strikes and entanglements, as the cause of death for the majority of 
right whales. The survey area overlaps a migratory corridor BIA for 
NARWs that extends from Massachusetts to Florida and from the coast to 
beyond the shelf break. Due to the fact that the survey activities are 
temporary and the spatial extent of sound produced by the survey would 
be small relative to the spatial extent of the available migratory 
habitat in the BIA, right whale migration is not expected to be 
impacted by the planned survey. Given the relatively small size of the 
ensonified area, it is unlikely that prey availability would be 
adversely affected by HRG survey operations. Required vessel strike 
avoidance measures will also decrease risk of ship strike during 
migration; no ship strike is expected to occur during TerraSond's 
activities. Additionally, only very limited take by Level B harassment 
of NARWs has been requested and is being authorized by NMFS as HRG 
survey operations are required to maintain and implement a 500 m 
shutdown zone. The 500 m shutdown zone for right whales is 
conservative, considering the Level B harassment isopleth for the 
acoustic source (i.e., sparker) is estimated to be 141 m, and thereby 
minimizes the potential for behavioral harassment of this species. As 
noted previously, Level A harassment is not expected due to the small 
estimated zones in conjunction with the aforementioned shutdown 
requirements. NMFS does not anticipate North Atlantic right whales 
takes that would result from TerraSond's activities would impact annual 
rates of recruitment or survival. Thus, any takes that occur would not 
result in population level impacts.

Other Marine Mammal Species With Active UMEs

    As noted previously, there are several active UMEs occurring in the 
vicinity of TerraSond's survey areas. Elevated humpback whale 
mortalities have occurred along the Atlantic coast from Maine through 
Florida since 2016. Of the cases examined, approximately half had 
evidence of human interaction (ship strike or entanglement). The UME 
does not yet provide cause for concern regarding population-level 
impacts. Despite the UME, the relevant population of humpback whales 
(the West Indies breeding population, or DPS) remains stable at 
approximately 12,000 individuals.
    Beginning in 2017, elevated minke whale strandings have occurred 
along the Atlantic coast from Maine through South Carolina, with 
highest numbers in Massachusetts, Maine, and New York. This event does 
not provide cause for concern regarding population level impacts, as 
the likely population abundance is greater than 20,000 whales.
    Elevated numbers of harbor seal and gray seal mortalities were 
first observed between 2018-2020 and, as part of a separate UME, again 
in 2022. These have occurred across Maine, New Hampshire, and 
Massachusetts. Based on tests conducted so far, the main pathogen found 
in the seals is phocine distemper virus (2018-2020) and avian influenza 
(2022), although additional testing to identify other factors that may 
be involved in the UMEs is underway. The UMEs do not provide cause for 
concern regarding population-level impacts to any of these stocks. For 
harbor seals, the population abundance is over 60,000 and annual M/SI 
(339) is well below PBR (1,729) (Hayes et al., 2021). The population 
abundance for gray seals in the United States is over 27,000, with an 
estimated abundance, including seals in Canada, of approximately 
450,000. In addition, the abundance of gray seals is likely increasing 
in the U.S. Atlantic as well as in Canada (Hayes et al., 2021).
    The required mitigation measures are expected to reduce the number 
and/or severity of takes for all species listed in Table 2, including 
those with active UMEs, to the level of least practicable adverse 
impact. In particular, they would provide animals the opportunity to 
move away from the sound source before HRG survey equipment reaches 
full energy, thus preventing them from being exposed to more severe 
Level B harassment. No Level A harassment is anticipated, even in the 
absence of mitigation measures, or authorized.
    NMFS expects that takes would be in the form of short-term Level B 
behavioral harassment by way of brief startling reactions and/or 
temporary vacating of the area, or decreased foraging (if such activity 
was occurring)--reactions that (at the scale and intensity anticipated 
here) are considered to be of low severity, with no lasting biological 
consequences. Since both the sources and marine mammals are mobile, 
animals would only be exposed briefly to a small ensonified area that 
might result in take. Required mitigation measures, such as shutdown 
zones and ramp up, would further reduce exposure to sound that could 
result in more severe behavioral harassment.

[[Page 31737]]

    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
     No mortality or serious injury is anticipated or 
authorized;
     No Level A harassment (PTS) is anticipated, even in the 
absence of mitigation measures, or authorized;
     Foraging success is not likely to be significantly 
impacted as effects on species that serve as prey species for marine 
mammals from the survey are expected to be minimal;
     The availability of alternate areas of similar habitat 
value for marine mammals to temporarily vacate the ensonified areas 
during the planned survey to avoid exposure to sounds from the 
activity;
     Take is anticipated to be primarily Level B behavioral 
harassment consisting of brief startling reactions and/or temporary 
avoidance of the ensonified area;
     While the survey area is within areas noted as a migratory 
BIA for NARWs, avoidance of the survey area due to the activities is 
not anticipated and would not likely affect migration. In addition, 
mitigation measures require shutdown at 500 m (almost four times the 
size of the Level B harassment isopleth of 141 m) to minimize the 
effects of any Level B harassment take of the species; and
     The required mitigation measures, including visual 
monitoring and shutdowns, are expected to minimize potential impacts to 
other marine mammals.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the required monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the activity will have a negligible impact on all affected marine 
mammal species or stocks.

Small Numbers

    As noted previously, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS proposes to authorize is below one-third of 
the estimated stock abundance for all species (total take is less than 
7.5 percent of the abundance of the affected stocks for all species, 
see Table 4). The figures presented in Table 4 are considered 
conservative estimates for purposes of the small numbers determination 
as they assume all takes represent different individual animals, which 
is unlikely to be the case.
    Based on the analysis contained herein of the activity (including 
the mitigation and monitoring measures) and the anticipated take of 
marine mammals, NMFS finds that small numbers of marine mammals would 
be taken relative to the population size of the affected species or 
stocks.

Unmitigable Adverse Impact Analysis and Determination

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

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species.
    NMFS has authorized the incidental take of four species of marine 
mammals which are listed under the ESA, including the North Atlantic 
right, fin, sei, and sperm whale, and has determined that these 
activities fall within the scope of activities analyzed in GARFO's 
programmatic consultation regarding geophysical surveys along the U.S. 
Atlantic coast in the three Atlantic Renewable Energy Regions 
(completed June 29, 2021; revised September 2021).

Authorization

    As a result of these determinations, NMFS has issued an IHA to 
TerraSond for conducting marine site characterization surveys in the 
New York Bight and Central Atlantic for a period of 1 year, provided 
the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. The IHA can be found at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-terrasond-limited-marine-site-characterization-surveys-new.

    Dated: May 15, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-10639 Filed 5-17-23; 8:45 am]
BILLING CODE 3510-22-P