[Federal Register Volume 89, Number 56 (Thursday, March 21, 2024)]
[Notices]
[Pages 20170-20182]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-05998]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD583]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Transco Lower New York Bay Lateral 
(LNYBL) Natural Gas Pipeline Maintenance in Sandy Hook Channel, NJ

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

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 
Transcontinental Gas Pipe Line Company LLC (Transco), to incidentally 
harass marine mammals during construction activities associated with a 
natural gas pipeline stabilization project in Sandy Hook Channel, New 
Jersey (NJ).

DATES: This authorization is effective from June 15, 2024, through June 
14, 2025.

ADDRESSES: 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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems accessing these documents, please call 
the contact listed below.

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

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

[[Page 20171]]

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 April 28, 2023, NMFS received a request from Transco for an IHA 
to take marine mammals incidental to pile driving activities associated 
with the LNYBL maintenance project in Sandy Hook Channel, NJ. On 
September 1, 2023 Transco submitted updates to the planned daily 
duration of pile driving and on October 27, 2023, Transco notified NMFS 
of changes to project timing. Following NMFS' review of the 
application, discussions between NMFS and Transco, and reanalysis 
following the aforementioned project changes, the application was 
deemed adequate and complete on November 2, 2023. Transco's request is 
for take of 11 species of marine mammal, by Level B harassment and, for 
a subset of 3 of these species, Level A harassment. Neither Transco 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 the Specified Activity

Overview

    Transco plans to stabilize the LNYBL natural gas pipeline that 
extends 34 miles (mi) [55 kilometers (km)] in Raritan Bay, Lower New 
York Bay, and the Atlantic Ocean from Morgan, NJ to Long Beach, New 
York (NY). During routine monitoring of the existing LNYBL, Transco 
identified seven discrete sections of the gas pipeline with either 
limited cover or exposure resulting from dynamic conditions. The LNYBL 
maintenance project involves the maintenance of pipeline sections with 
seven corresponding ``work areas'' that encompass all in-water 
temporary work spaces within NY and NJ where project-related activities 
may cause sediment disturbance. To stabilize the pipeline, Transco will 
place rock over the pipeline at seven distinct work areas. At Work Area 
3, near Sandy Hook Channel, NJ, Transco plans to install 960 sheet 
piles to provide additional stability and protection, and to mitigate 
future seabed lowering and erosion along the north flank of Sandy Hook 
Channel. Activities included as part of the project with potential to 
affect marine mammals include vibratory and impact pile driving of 
steel sheet piles at Work Area 3. The pile driving activities are 
expected to occur on 80 days between June and September 2024. Other in-
water work described above will not cause take of marine mammals.
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed IHA (88 FR 
84789, December 6, 2023). Since that time, no changes have been made to 
the planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for the 
description of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to Transco was published 
in the Federal Register on December 6, 2023 (88 FR 84789). That notice 
described, in detail, Transco's 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 any other aspect of the notice of proposed IHA, and 
requested that interested persons submit relevant information, 
suggestions, and comments. This proposed notice was available for a 30-
day public comment period. During the 30-day public comment period, the 
United States Geological Survey noted that they have ``no comment at 
this time.'' NMFS received no other public comments.

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 all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/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 1 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 anticipated or authorized here, 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 managed stocks in this region are assessed in 
NMFS' U.S. Atlantic and Gulf of Mexico SARs (Hayes et al., 2022; Hayes 
et al., 2023). All values presented in table 1 are available online at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                              Table 1--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 Balaenopteridae (rorquals):
    Fin Whale.......................  Balaenoptera physalus..  Western N Atlantic.....  E, D, Y             6,802 (0.24, 5,573,            11        1.8
                                                                                                             2016).
    Humpback Whale..................  Megaptera novaeangliae.  Gulf of Maine..........  -, -, N             1,396.................         22      12.15

[[Page 20172]]

 
    Minke Whale.....................  Balaenoptera             Canadian Eastern         -, -, N             21,968 (0.31, 17,002,         170       10.6
                                       acutorostrata.           Coastal.                                     2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Atlantic White-sided Dolphin....  Lagenorhynchus acutus..  Western N Atlantic.....  -, -, N             93,233 (0.71, 54,443,         544         27
                                                                                                             2016).
    Bottlenose Dolphin..............  Tursiops truncatus.....  Northern Migratory       -, -, Y             6,639, (0.41, 4,759,           48  12.2-21.5
                                                                Coastal.                                     2016).
                                                               Western North Atlantic   -, -, N             62,851 (0.23, 51,914,         519         28
                                                                Offshore.                                    2016).
    Common Dolphin..................  Delphinus delphis......  Western N Atlantic.....  -, -, N             172,974 (0.21,              1,452        390
                                                                                                             145,216, 2016).
    Atlantic Spotted Dolphin........  Stenella frontalis.....  Western N Atlantic.....  -, -, N             39,921 (0.27, 32,032,         320          0
                                                                                                             2016).
Family Phocoenidae (porpoises):
    Harbor Porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of     -, -, N             95,543 (0.31, 74,034,         851        164
                                                                Fundy.                                       2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harp Seal.......................  Pagophilus               Western N Atlantic.....  -, -, N             7.6M (UNK, 7.1M, 2019)    426,000    178,573
                                       groenlandicus.
    Harbor Seal.....................  Phoca vitulina.........  Western N Atlantic.....  -, -, N             61,336 (0.08, 57,637,       1,729        339
                                                                                                             2018).
    Gray Seal \4\...................  Halichoerus grypus.....  Western N Atlantic.....  -, -, N             27,300 (0.22, 22,785,       1,458      4,453
                                                                                                             2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual Mortality and Serious Injury (M/SI) often cannot be determined precisely and is in some cases presented
  as a minimum value or range.
\4\ This stock abundance estimate is only for the U.S. portion of this stock. The actual stock abundance, including the Canadian portion of the
  population, is estimated to be approximately 424,300 animals. The PBR value listed here is only for the U.S. portion of the stock, while M/SI reflects
  both the Canadian and U.S. portions.

    A detailed description of the species likely to be affected by the 
Transco LNYBL Maintenance project, including brief introductions to the 
species and relevant stocks as well as available information regarding 
population trends and threats, and information regarding local 
occurrence, were provided in the Federal Register notice for the 
proposed IHA (88 FR 84789, December 6, 2023); 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 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al., (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in table 2.

                  Table 2--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen         7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).

[[Page 20173]]

 
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al., (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al., 
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 Transco's construction 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the project area. The notice of the 
proposed IHA (88 FR 84789, December 6, 2023) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from Transco's construction on marine 
mammals and their habitat. That information and analysis is 
incorporated by reference into this final IHA determination and is not 
repeated here; please refer to the notice of proposed IHA (88 FR 84789, 
December 6, 2023).

Estimated Take of Marine Mammals

    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 will be by Level B harassment, as use of the 
acoustic sources (i.e., impact and vibratory pile driving) has the 
potential to result in disruption of behavioral patterns for individual 
marine mammals. There is also some potential for auditory injury (Level 
A harassment) to result for phocids because predicted auditory injury 
zones are relatively large, and seals are expected to be relatively 
common and are more difficult to detect at greater distances. The 
planned mitigation and monitoring measures are expected to minimize the 
severity of the taking to the extent practicable.
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
authorized 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; 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 
are reasonably expected to be behaviorally harassed (equated to Level B 
harassment) or to incur Permanent Threshold Shift (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 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive 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.
    Transco's planned activity includes the use of continuous 
(vibratory pile driving) and impulsive (impact pile driving) sources, 
and therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa is/
are applicable.

[[Page 20174]]

    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). Transco's 
planned activity includes the use of impulsive (impact pile driving) 
and non-impulsive (vibratory pile driving) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

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.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the planned project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., pile driving).
    The project includes vibratory and impact pile driving. Source 
levels for these activities are based on reviews of measurements of the 
same or similar types and dimensions of piles available in the 
literature. Source levels for each pile size and activity are presented 
in table 4. Source levels for vibratory installation and removal of 
piles of the same diameter are assumed to be the same.

Table 4--Estimates of Mean Underwater Sound Levels Generated During Vibratory and Impact Pile Installation of 36-
                                              Inch Steel Sheet Pile
----------------------------------------------------------------------------------------------------------------
               Hammer type                   dB rms       dB SEL      dB peak           Literature source
----------------------------------------------------------------------------------------------------------------
Vibratory *.............................        **182          N/A          N/A  Quijano et al., 2018.
Impact *................................          190          180          205  Caltrans, 2015.
----------------------------------------------------------------------------------------------------------------
Note: dB peak = peak sound level; rms = root mean square; SEL = sound exposure level.
* Vibratory source levels are referenced at 1 m and the impact source levels are referenced at 10 m.
** Since vibratory pile installation is a continuous, non-impulsive source, it was assumed that the dB rms
  source levels are the same as the dB SEL source level reported in Quijano et al. (2018).

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R1/R2), where

TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. Site-specific 
transmission loss data for the Raritan Bay is not available; therefore, 
the default coefficient of 15 is used to determine the distances to the 
harassment thresholds.
    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources such as pile driving, the optional User Spreadsheet 
tool predicts the distance at which, if a marine mammal remained at 
that distance for the duration of the activity, it will be expected to 
incur PTS. Inputs used in the optional User Spreadsheet tool, and

[[Page 20175]]

the resulting estimated isopleths, are reported below (table 5). The 
resulting estimated isopleths and the calculated Level B harassment 
isopleths are reported in table 6.

                    Table 5--User Spreadsheet Inputs
------------------------------------------------------------------------
       Spreadsheet tab used           A.1) Vibratory    E.1) Impact pile
-----------------------------------    pile driving         driving
                                   -------------------------------------
        Source level (SPL)               182 RMS            180 SEL
------------------------------------------------------------------------
                        36-inch steel sheet piles
------------------------------------------------------------------------
Transmission Loss Coefficient.....                 15                 15
Weighting Factor Adjustment (kHz).                2.5                  2
Activity Duration per pile                         10                N/A
 (minutes)........................
Number of strikes per pile........  .................                520
Number of piles per day...........                 12                 12
Distance of sound pressure level                    1                 10
 measurement......................
------------------------------------------------------------------------


                                              Table 6--Level A Harassment and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Level A harassment isopleths (m) [verbar] area  of harassment zone (km\2\)       Level B
                                                                                                *                                          harassment
                                                          ----------------------------------------------------------------------------    isopleth (m)
                       Hammer type                                                                                                      [verbar] area of
                                                                   LF                 MF                 HF                 PW          harassment zone
                                                                                                                                           (km\2\) *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                36-inch Steel Sheet Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving...................................               27.2                2.4               40.3               16.6    13,594 [verbar]
                                                                                                                                                  426.13
Impact Pile Driving......................................   2,135.6 [verbar]      76.0 [verbar]   2,543.9 [verbar]   1,142.9 [verbar]              1,000
                                                                       18.99               0.30              25.23               7.72
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Harassment zone areas are clipped by viewshed.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations.
    Transco applied the Duke University Marine Geospatial Ecology 
Laboratory marine mammal habitat-based density models (https://seamap.env.duke.edu/models/Duke/EC/) to estimate take from vibratory 
and impact pile driving (Roberts et al., 2016; Roberts et al., 2023). 
These density data incorporate aerial and shipboard line-transect data 
from NMFS and other organizations and incorporate data from 8 
physiographic and 16 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). Most recently, all models 
were updated in 2022 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 project area (animals/km\2\) were obtained using the 
most recent model results for all taxa (Roberts et al., 2023).
    For each species, the average monthly density (June-September) near 
work area 3, Sandy Hook Channel, was calculated (table 7). 
Specifically, in a Geographic Information Systems, density rasters were 
clipped to polygons representing the zone of influence for Level A 
harassment zones for each hearing group and the largest Level B 
harassment zone, which applies to all hearing groups. Densities in 
Roberts et al., (2023) are provided in individuals per 100 square km, 
however they were converted to individuals per square km for ease of 
calculation. The monthly maximum density of individuals per square km 
for each zone of influence was averaged over the months of June to 
September near work area 3 to provide a single density estimate for 
each species or species group. The available density information 
provides densities for seals as a guild due to difficulty in 
distinguishing these species at sea. Similarly, density information for 
bottlenose dolphins does not differentiate between stocks. The 
resulting density values (table 7) were used to calculate take 
estimates of marine mammals for sheet pile installation activities. 
Note that other data sources were evaluated for pinnipeds (e.g., Save 
Coastal Wildlife reports) but were found unsuitable due to data quality 
and applicability.

                         Table 7--Average Monthly Density of Species in the Project Area
                                                [June-September]
----------------------------------------------------------------------------------------------------------------
                                                         Average monthly density       Average monthly density
                                                       (individual/km\2\) used in    (individual/km\2\) used in
                       Species                        Level B take calculations at  Level A take calculations at
                                                         work area 3, Sandy Hook       work area 3, Sandy Hook
                                                        Channel (June-September)      Channel (June-September)
----------------------------------------------------------------------------------------------------------------
Fin Whale...........................................                   1.41361E-04                   4.53952E-06

[[Page 20176]]

 
Humpback Whale......................................                   9.37889E-05                   2.14387E-05
Minke Whale.........................................                   2.34113E-04                   3.12779E-05
Atlantic white-sided dolphin........................                   4.97340E-05                   6.98975E-07
Bottlenose dolphin..................................                   1.88295E-01                   4.76450E-02
Harbor porpoise.....................................                   1.64816E-04                   3.27277E-05
Common dolphin......................................                   5.91282E-04                   1.24663E-05
Atlantic Spotted Dolphin............................                   2.38665E-04                   8.76649E-07
Harp Seals, Gray Seals, Harbor Seals................                       0.11387                       0.11130
----------------------------------------------------------------------------------------------------------------

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 authorized.
    Take estimates are the product of density, ensonified area, and 
number of days of pile driving work. Specifically, take estimates are 
calculated by multiplying the expected densities of marine mammals in 
the activity area(s) by the area of water likely to be ensonified above 
the NMFS defined threshold levels in a single day (24-hour period). 
Transco used the construction method that produced the largest isopleth 
to estimate exposure of marine mammal noise impacts (i.e., the largest 
ensonified area estimated for vibratory pile driving was used to 
estimate potential takes by Level B harassment, and the hearing group-
specific ensonified areas estimated for impact pile driving were used 
to estimate potential Level A harassment). Next, that product is 
multiplied by the number of days vibratory or impact pile driving is 
likely to occur. The exposure estimate was rounded to the nearest whole 
number at the end of the calculation. A summary of this method is 
illustrated in the following formula:

Estimated Take = D x ZOI x # of construction days

Where:

D = density estimate for each species within the ZOI
ZOI = maximum daily ensonified area (km\2\) to relevant thresholds

    For bottlenose dolphins, the density data presented by Roberts et 
al., (2023) does not differentiate between bottlenose dolphin stocks. 
Thus, the take estimate for bottlenose dolphins calculated by the 
method described above resulted in an estimate of the total number of 
bottlenose dolphins expected to be taken, from all stocks (for a total 
of 6,419 takes by Level B harassment). However, as described above, 
both the Western North Atlantic Northern Migratory Coastal stock and 
the Western North Atlantic Offshore stock have the potential to occur 
in the project area. Because approximately 95 percent of the project 
area occurs in waters shallower than 20 m, we assign take to stock 
accordingly. Thus, we assume that 95 percent of the total authorized 
bottlenose dolphin takes will accrue to the Western North Atlantic 
Offshore stock (total 6,098 takes by Level B harassment), and 5 percent 
to the Western North Atlantic Northern Migratory Coastal stock (total 
321 takes by Level B harassment) (table 8).
    Additional data regarding average group sizes from survey effort in 
the region was considered to ensure adequate take estimates are 
evaluated. Take estimates for several species were adjusted based upon 
average groups sizes derived from NOAA Atlantic Marine Assessment 
Program for Protected Species data from 2010-2019 shipboard distance 
sampling surveys (Palka et al., 2021). This is particularly true for 
uncommon or rare species with very low densities in the models. These 
calculated take estimates were adjusted for these species as follows:
     Atlantic white-sided dolphin: Only 1 take by Level B 
harassment was estimated but takes authorized were increased to the 
average number of dolphins in a group reported in Palka et al., 2021 (n 
= 12);
     Common dolphin: Only 26 takes were estimated but 
authorized takes were increased to the average number of dolphins in a 
group reported in Palka et al., 2021 (n = 30);
     Atlantic spotted dolphin: Only 9 takes were estimated but 
authorized takes were increased to the average number of dolphins in a 
group reported in Palka et al., 2021 (n = 24);

          Table 8--Authorized Take by Stock and Harassment Type and as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                                          Authorized take
                                                                    --------------------------     Take as a
               Species                             Stock               Level B      Level A      percentage of
                                                                      harassment   harassment   stock abundance
----------------------------------------------------------------------------------------------------------------
Fin Whale............................  Western North Atlantic......            5            0                 <1
Humpback Whale.......................  Gulf of Maine...............            3            0                 <1
Minke Whale..........................  Canadian East Coast.........            8            0                 <1
Atlantic White-sided Dolphin.........  Western North Atlantic......           12            0                 <1
Bottlenose Dolphin...................  Northern Migratory Coastal..        6,098            0                 92
                                       Western North Atlantic                321            0                 <1
                                        Offshore.
Harbor Porpoise......................  Gulf of Maine/Bay of Fundy..            6            0                 <1
Common Dolphin.......................  Western North Atlantic......           30            0                 <1
Atlantic Spotted Dolphin.............  Western North Atlantic......           24            0                 <1
Harbor Seal..........................  Western North Atlantic......        3,813           69                6.3
Gray Seal............................  Western North Atlantic......                                           <1

[[Page 20177]]

 
Harp Seal............................  Western North Atlantic......                                           <1
----------------------------------------------------------------------------------------------------------------

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. 
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.
    Transco has indicated that pile driving will be conducted between 
June 15 and September 15, a time of year when North Atlantic Right 
Whales are unlikely to occur near the project area. Transco will 
implement the following mitigation requirements:
    Shutdown Zones--For all pile driving activities, Transco will 
implement shutdowns within designated zones. The purpose of a shutdown 
zone is generally to define an area within which shutdown of the 
activity will occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
vary based on the activity type and marine mammal hearing group (table 
9). In most cases, the shutdown zones are based on the estimated Level 
A harassment isopleth distances for each hearing group. However, in 
cases where it will be challenging to detect marine mammals at the 
Level A harassment isopleth and frequent shutdowns are expected to 
create practicability concerns (e.g., for phocids during impact pile 
driving), smaller shutdown zones have been established (table 9). 
Additionally, Transco has agreed to implement a minimum shutdown zone 
of 60 m during all pile driving activities.
    Finally, construction supervisors and crews, Protected Species 
Observers (PSOs), and relevant Transco staff must avoid direct physical 
interaction with marine mammals during construction activity. If a 
marine mammal comes within 10 m of such activity, operations must cease 
and vessels must reduce speed to the minimum level required to maintain 
steerage and safe working conditions, as necessary to avoid direct 
physical interaction. If an activity is delayed or halted due to the 
presence of a marine mammal, the activity may not commence or resume 
until either the animal has voluntarily exited and been visually 
confirmed beyond the shutdown zone indicated in table 9 or 15 minutes 
have passed without re-detection of the animal.
    Construction activities must be halted upon observation of a 
species for which incidental take is not authorized or a species for 
which incidental take has been authorized but the authorized number of 
takes has been met entering or within the harassment zone. In the case 
of North Atlantic right whale, construction activities must be halted 
upon observation of this species at any distance, regardless of its 
proximity to a harassment zone.

                                             Table 9--Shutdown Zones
----------------------------------------------------------------------------------------------------------------
                                                                        Shutdown zones (m)
                                                ----------------------------------------------------------------
           Activity                Pile type      North Atlantic      Low          Mid-         High
                                                   right whale     frequency    frequency    frequency    Phocid
----------------------------------------------------------------------------------------------------------------
Vibratory Installation.......  36-inch sheet...  Any distance...                        60
                                                                 -----------------------------------------------
Impact Installation..........  ................  ...............        1,000           80          200      150
----------------------------------------------------------------------------------------------------------------

    Protected Species Observers--The number and placement of PSOs 
during all construction activities (described in the Monitoring and 
Reporting section) will ensure that the entire shutdown zone is 
visible. Transco will employ at least two PSOs for all pile driving 
activities.
    Monitoring for Level A and Level B harassment--PSOs will monitor 
the shutdown zones and beyond to the extent that PSOs can see. 
Monitoring beyond the shutdown zones enables observers to be aware of 
and communicate the presence of marine mammals in the project areas 
outside the shutdown zones and thus prepare for a potential cessation 
of activity should the animal enter the shutdown zone. If a marine 
mammal enters either

[[Page 20178]]

harassment zone, PSOs will document the marine mammal's presence and 
behavior.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving of 30 
minutes or longer occurs, PSOs will observe the shutdown, Level A 
harassment, and Level B harassment zones for a period of 30 minutes. 
Pre-start clearance monitoring must be conducted during periods of 
visibility sufficient for the lead PSO to determine that the shutdown 
zones are clear of marine mammals. If the shutdown zone is obscured by 
fog or poor lighting conditions, in-water construction activity will 
not be initiated until the entire shutdown zone is visible. Pile 
driving may commence following 30 minutes of observation when the 
determination is made that the shutdown zones are clear of marine 
mammals. If a marine mammal is observed entering or within shutdown 
zones, pile driving activity must be delayed or halted. If pile driving 
is delayed or halted due to the presence of a marine mammal, the 
activity may not commence or resume until either the animal has 
voluntarily exited and been visually confirmed beyond the shutdown zone 
or 15 minutes have passed without re-detection of the animal. If a 
marine mammal for which Level B harassment take is authorized is 
present in the Level B harassment zone, activities may begin.
    Soft-Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
are be required to provide an initial set of three strikes from the 
hammer at reduced energy, with each strike followed by a 30-second 
waiting period. This procedure will be conducted a total of three times 
before impact pile driving begins. Soft start will be implemented at 
the start of each day's impact pile driving and at any time following 
cessation of impact pile driving for a period of 30 minutes or longer. 
Soft start is not required during vibratory pile driving activities.
    Based on our evaluation of the applicant's planned measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
listed 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.
    Visual Monitoring--Marine mammal monitoring during pile driving 
activities must be conducted by NMFS-approved PSOs in a manner 
consistent with the following:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor), and have no other assigned tasks 
during monitoring periods;
     At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field) or training 
for experience performing the duties of a PSO during construction 
activities pursuant to a NMFS-issued incidental take authorization;
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator will be designated. The lead 
observer will be required to have prior experience working as a marine 
mammal observer during construction activity pursuant to a NMFS-issued 
incidental take authorization; and,
     PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    PSOs should also have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including, but not limited to, the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and,
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Visual monitoring will be conducted by a minimum of two trained 
PSOs positioned at suitable vantage points on or near the maintenance 
barge. One PSO will have an unobstructed view of all water within the 
shutdown zone. Remaining PSOs will observe as much as the Level A and 
Level B harassment zones as possible.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after all inwater construction activities. In addition, PSOs 
will record all incidents of marine mammal occurrence, regardless of 
distance from activity, and will document any

[[Page 20179]]

behavioral reactions in concert with distance from piles being driven 
or removed. Pile driving activities include the time to install or 
remove a single pile or series of piles, as long as the time elapsed 
between uses of the pile driving equipment is no more than 30 minutes.

Reporting

    Transco will submit a draft marine mammal monitoring report to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to a requested date of issuance of any future IHAs for the 
project, or other projects at the same location, whichever comes first. 
The marine mammal monitoring report will include an overall description 
of work completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report will include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including: (1) The number and type of piles that 
were driven and the method (e.g., impact or vibratory); and, (2) Total 
duration of driving time for each pile (vibratory driving) and number 
of strikes for each pile (impact driving);
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information: (1) Name of PSO who sighted the animal(s) and PSO location 
and activity at time of sighting; (2) Time of sighting; (3) 
Identification of the animal(s) (e.g., genus/species, lowest possible 
taxonomic level, or unidentified), PSO confidence in identification, 
and the composition of the group if there is a mix of species; (4) 
Distance and location of each observed marine mammal relative to the 
pile being driven for each sighting; (5) Estimated number of animals 
(min/max/best estimate); (6) Estimated number of animals by cohort 
(adults, juveniles, neonates, group composition, etc.); (7) Animal's 
closest point of approach and estimated time spent within the 
harassment zone; (8) Description of any marine mammal behavioral 
observations (e.g., observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g., no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
     Number of marine mammals detected within the harassment 
zones, by species; and,
     Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specific 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    A final report must be prepared and submitted within 30 calendar 
days following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered final. All PSO data 
will be submitted electronically in a format that can be queried such 
as a spreadsheet or database and will be submitted with the draft 
marine mammal report.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Holder must report the 
incident to the Office of Protected Resources (OPR), NMFS 
([email protected] and [email protected]) and 
Greater Atlantic Region New England/Mid-Atlantic Regional Stranding 
Coordinator (978-282-8478 or 978-281-9291) as soon as feasible. If the 
death or injury was clearly caused by the specified activity, the 
Holder must immediately cease the activities until NMFS OPR is able to 
review the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of this IHA. The Holder must not resume their activities until notified 
by NMFS. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

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 1, given that many of 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 described independently in the analysis below.
    Pile driving associated with the Transco LNYBL maintenance project, 
as outlined previously, has the potential to disturb or displace marine 
mammals. Specifically, the specified activities may result in take, in 
the form of Level B harassment and, for some species, Level A 
harassment, from underwater sounds generated by pile driving.
    No serious injury or mortality is expected, even in the absence of 
required mitigation measures, given the nature of the activities. 
Further, no take by Level A harassment is anticipated for low-
frequency, mid-frequency, or high-frequency cetaceans. The potential 
for

[[Page 20180]]

harassment will be minimized through the implementation of planned 
mitigation measures (see Mitigation section).
    Take by Level A harassment is expected for pinnipeds (harbor seal, 
harp seal, and gray seal). Any take by Level A harassment is expected 
to arise from, at most, a small degree of PTS (i.e., minor degradation 
of hearing capabilities within regions of hearing that align most 
completely with the energy produced by impact pile driving such as the 
low-frequency region below 2 kilohertz (kHz), not severe hearing 
impairment or impairment within the ranges of greatest hearing 
sensitivity. Animals would need to be exposed to higher levels and/or 
longer duration than are expected to occur here in order to incur any 
more than a small degree of PTS.
    Further, the amount of take authorized by Level A harassment is 
very low for all marine mammal stocks and species. For 8 species, NMFS 
anticipates no Level A harassment take over the duration of Transco's 
planned activities; for pinnipeds, NMFS expects no more than 69 takes 
by Level A harassment across all 3 pinniped species (harbor seal, gray 
seal, harp seal). If hearing impairment occurs, it is most likely that 
the affected animal would lose only a few decibels in its hearing 
sensitivity. Due to the small degree anticipated, any PTS potential 
incurred would not be expected to affect the reproductive success or 
survival of any individuals, much less result in adverse impacts on the 
species or stock.
    Additionally, some subset of the individuals that are behaviorally 
harassed could also simultaneously incur some small degree of TTS for a 
short duration of time. However, since the hearing sensitivity of 
individuals that incur TTS is expected to recover completely within 
minutes to hours, it is unlikely that the brief hearing impairment 
would affect the individual's long-term ability to forage and 
communicate with conspecifics, and would therefore not likely impact 
reproduction or survival of any individual marine mammal, let alone 
adversely affect rates of recruitment or survival of the species or 
stock.
    As described above, NMFS expects that marine mammals will likely 
move away from an aversive stimulus, especially at levels that would be 
expected to result in PTS, given sufficient notice through use of soft 
start. Transco would also shut down pile driving activities if marine 
mammals enter the shutdown zones (table 9) further minimizing the 
degree of PTS that would be incurred.
    Effects on individuals that are taken by Level B harassment in the 
form of behavioral disruption, on the basis of reports in the 
literature as well as monitoring from other similar activities, will 
likely be limited to reactions such as avoidance, increased swimming 
speeds, increased surfacing time, or decreased foraging (if such 
activity were occurring) (e.g., Thorson and Reyff, 2006). Most likely, 
individuals will simply move away from the sound source and temporarily 
avoid the area where pile driving is occurring. If sound produced by 
project activities is sufficiently disturbing, animals are likely to 
simply avoid the area while the activities are occurring. We expect 
that any avoidance of the project areas by marine mammals will be 
temporary in nature and that any marine mammals that avoid the project 
areas during construction will not be permanently displaced. Short-term 
avoidance of the project areas and energetic impacts of interrupted 
foraging or other important behaviors is unlikely to affect the 
reproduction or survival of individual marine mammals, and the effects 
of behavioral disturbance on individuals is not likely to accrue in a 
manner that will affect the rates of recruitment or survival of any 
affected stock.
    As described above, humpback whales, and gray, harbor and harp 
seals are experiencing ongoing Unusual Mortality Events (UMEs). With 
regard to humpback whales, 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 Distinct Population Segment (DPS) remains healthy. The 
West Indies DPS, which consists of the whales whose breeding range 
includes the Atlantic margin of the Antilles from Cuba to northern 
Venezuela, and whose feeding range primarily includes the Gulf of 
Maine, eastern Canada, and western Greenland, was delisted. The status 
review identified harmful algal blooms, vessel collisions, and fishing 
gear entanglements as relevant threats for this DPS, but noted that all 
other threats are considered likely to have no or minor impact on 
population size or the growth rate of this DPS (Bettridge et al., 
2015). As described in Bettridge et al., (2015), the West Indies DPS 
has a substantial population size (i.e., approximately 10,000; Stevick 
et al., 2003; Smith et al., 1999; Bettridge et al., 2015), and appears 
to be experiencing consistent growth.
    In regards to pinnipeds (harbor seals, gray seals and harp seals), 
we do not expect takes that may be authorized under this IHA to 
exacerbate or compound upon ongoing UMEs. Between July 2018 and March 
2020, elevated seal mortalities occurred across ME, NH and MA, and as 
far south as VA due to phocine distemper virus (the UME is still active 
but pending closure). Since June 2022, a UME has been declared for 
Northeast pinnipeds in which elevated numbers of sick and dead harbor 
seals, gray seals, and harp seals have been documented along the 
southern and central coast of ME (NOAA Fisheries, 2022). Between June 
1, 2022 and July 16, 2023, 65 grays seals, 379 harbor seals, and 6 harp 
seals have stranded. As noted previously, no injury, serious injury, or 
mortality is expected or will be authorized, and takes of harbor seal, 
gray seal, and harp seal will be minimized through the incorporation of 
the required mitigation measures. The population abundance for these 
species is 61,336, 27,300, and 7.6 million, respectively (Hayes et al., 
2022). The 3,882 takes that may be authorized across these species 
represent a small proportion of each population and as such we do not 
expect this authorization to exacerbate or compound upon these UMEs.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. No ESA-designated 
critical habitat or recognized Biologically Important Areas are located 
within the project area. The project activities are not expected to 
modify existing marine mammal habitat for a significant amount of time. 
The activities may cause a low level of turbidity in the water column 
and some fish may leave the area of disturbance, thus temporarily 
impacting marine mammals' foraging opportunities in a limited portion 
of the foraging range; but, because of the short duration of the 
activities and the relatively small area of the habitat that may be 
affected (with no known particular importance to marine mammals), the 
impacts to marine mammal habitat are not expected to cause significant 
or long-term negative consequences. The closest pinniped haulout is 
located 2.9 km from the work area but does not intersect with the 
harassment zones.
    For all species and stocks, take is expected to occur within a 
limited, relatively confined area (primarily Raritan Bay) of the 
stock's range, which is not of particular importance for marine mammals 
that may occur there. Given the availability of suitable habitat 
nearby, any displacement of marine mammals from the project areas is 
not expected to affect marine mammals' fitness, survival, and 
reproduction due to the limited geographic area that will

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be affected in comparison to the much larger habitat for marine mammals 
outside the bay along the NJ and NY coasts. Additionally, NMFS 
anticipates that the prescribed mitigation will minimize the duration 
and intensity of expected harassment events.
    Some individual marine mammals in the project area, such as harbor 
seals or bottlenose dolphins, may be present and be subject to repeated 
exposure to sound from pile driving activities on multiple days. 
However, pile driving and extraction is not expected to occur on every 
day, and these individuals will likely return to normal behavior during 
gaps in pile driving activity within each day of construction and in 
between work days. As discussed above, individuals could temporarily 
relocate during construction activities to reduce exposure to elevated 
sound levels from the project. Additionally, haulout habitat available 
for pinnipeds does not intersect with the harassment zones. Therefore, 
any behavioral effects of repeated or long duration exposures are not 
expected to negatively affect survival or reproductive success of any 
individuals. Thus, even repeated Level B harassment of some small 
subset of an overall stock is unlikely to result in any effects on 
rates of reproduction and survival of the stock.
    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 any of the species or stocks 
through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     The anticipated impacts of the planned activity on marine 
mammals will be temporary behavioral changes due to avoidance of the 
project area and limited instances of Level A harassment in the form of 
a slight PTS for pinnipeds. Potential instances of exposure above the 
Level A harassment threshold are expected to be relatively low for most 
species;
     The availability of alternate areas of similar habitat 
value nearby;
     Effects on species that serve as prey species for marine 
mammals from the planned project are expected to be short-term and are 
not expected to result in significant or long-term consequences for 
individual marine mammals, or to contribute to adverse impacts on their 
populations;
     There are no known important feeding, breeding, or calving 
areas in the project area; and,
     The established mitigation measures, including visual 
monitoring, shutdown zones, and soft start, are expected to minimize 
potential impacts to 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 planned activity will have a negligible impact on all affected 
marine mammal species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
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.
    We authorize incidental take of 12 marine mammal stocks. The total 
amount of taking authorized is well below one-third of the estimated 
stock abundance for all species except for the western north Atlantic 
northern coastal migratory stock of bottlenose dolphins (table 8).
    The total number of authorized takes for bottlenose dolphins, if 
assumed to accrue solely to new individuals of the northern migratory 
coastal stock, is >90 percent of the total stock abundance, which is 
currently estimated as 6,639. However, these numbers represent the 
estimated incidents of take, not the number of individuals taken. That 
is, it is highly likely that a relatively small subset of these 
bottlenose dolphins will be harassed by project activities.
    Western North Atlantic Northern Migratory Coastal bottlenose 
dolphins make broad scale, seasonal migrations in coastal waters of the 
Western north Atlantic. During the warm months, when the project is 
planned, their range extends from the shoreline to the 20 m isobaths 
between Assateague, VA to Long Island, NY (Garrison et al., 2017b), an 
area spanning approximately 300 linear km of coastline. It is likely 
that the majority of the Western North Atlantic Northern Migratory 
Coastal bottlenose dolphins will not occur within waters ensonified by 
project activities.
    In summary, the Western North Atlantic Northern Migratory Coastal 
bottlenose dolphins are not expected to occur in a significant portion 
of the larger ZOI. Given that the specified activity will be stationary 
within an area not recognized as any special significance that would 
serve to attract or aggregate dolphins, we therefore believe that the 
estimated numbers of takes, were they to occur, likely represent 
repeated exposures of a much smaller number of bottlenose dolphins and 
that these estimated incidents of take represent small numbers of 
bottlenose dolphins.
    Based on the analysis contained herein of the planned activity 
(including the required mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will 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 will 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, in this case with the NMFS Greater 
Atlantic Regional Fisheries Office (GARFO).
    OPR requested initiation of consultation with GARFO under section 7 
of the ESA on the issuance of the IHA to Transco under section 
10(a)(5)(D) of the MMPA. On March 6, 2024, GARFO concluded consultation 
with OPR and the U.S. Army Corps of Engineers concerning the conduct of 
the specified activities which concluded that the

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issuance of the authorization is not likely to adversely affect any 
listed marine mammal species.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must evaluate our proposed action (i.e., the issuance of an IHA) 
and alternatives with respect to potential impacts on the human 
environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NAO 216-6A, which do not 
individually or cumulatively have the potential for significant impacts 
on the quality of the human environment and for which we have not 
identified any extraordinary circumstances that precludes this 
categorical exclusion. Accordingly, NMFS has determined that the 
issuance of this IHA qualifies to be categorically excluded from 
further NEPA review.

Authorization

    NMFS has issued an IHA to Transco for the potential harassment of 
small numbers of 11 marine mammal species incidental to the LNYBL 
Maintenance project in Sandy Hook Channel, NJ, that includes the 
previously explained mitigation, monitoring and reporting requirements.

    Dated: March 14, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2024-05998 Filed 3-20-24; 8:45 am]
BILLING CODE 3510-22-P