[Federal Register Volume 87, Number 66 (Wednesday, April 6, 2022)]
[Notices]
[Pages 19886-19903]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-07257]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB918]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Navy Construction of the 
Multifunctional Expansion of Dry Dock 1 at Portsmouth Naval Shipyard, 
Kittery, Maine

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

ACTION: Notice; issuance of an incidental harassment authorization.

-----------------------------------------------------------------------

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 
the U.S. Navy (Navy) to incidentally harass, by Level A and B 
harassment, marine mammals during activities associated with the 
Multifunctional Expansion of Dry Dock 1 at Portsmouth Naval Shipyard, 
Kittery, Maine

DATES: This Authorization is effective from April, 1 2022 through March 
31, 2023.

FOR FURTHER INFORMATION CONTACT: Stephanie Egger, 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: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. 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 issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be 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 such 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 such 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 September 2, 2021, NMFS received a request from the Navy for an 
IHA to take marine mammals incidental to construction activities 
associated with the multifunctional expansion of Dry Dock 1 project 
(also referred to as P-831) at Portsmouth Naval Shipyard in Kittery, 
Maine. The Navy submitted a revised version of the application on 
December 21, 2021. The application was deemed adequate and complete on 
February 10, 2022. The Navy's request is for take of harbor porpoises, 
harbor seals, gray seals, harp seals, and hooded seals by Level A 
harassment and Level B harassment. Neither the Navy nor NMFS expects 
serious injury or mortality to result from this activity; therefore, an 
IHA is appropriate.

Description of Proposed Activity

    The shipyard is located in the Piscataqua River in Kittery, Maine. 
The Piscataqua River originates at the boundary of Dover, New 
Hampshire, and Eliot, Maine Multifunctional Expansion of Dry Dock 1 (P-
381) is one of three projects that support the overall expansion and 
modification of Dry Dock 1, located in the western extent of the 
shipyard. The previous two projects, construction of a super flood 
basin (P-310) and extension of portal crane rail and utilities (P-1074) 
are currently under construction. Work associated with P-310 and P-1074 
has been and/or is being completed under the separate IHAs issued by 
NMFS. The projects have been phased to support Navy mission schedules. 
P-381 will be constructed within the same footprint of the super flood 
basin over an approximated 7-year period. In-water activities are 
expected to occur within the first 5 years, between April 2022 and

[[Page 19887]]

April 2027. This IHA request is for the first year of in-water 
construction for P-381 occurring from April 2022 through April 2023. 
All work beyond year 1 is anticipated to be requested in a rulemaking/
Letter of Authorization (LOA) application submission to NMFS.
    The purpose of the proposed project, Multifunctional Expansion of 
Dry Dock 1 (P-381), is to modify the super flood basin to create two 
additional dry docking positions (Dry Dock 1 North and Dry Dock 1 West) 
in front of the existing Dry Dock 1 East. The super flood basin 
provides the starting point for the P-381 work (see Figure 1-2 of the 
application).
    Year 1 construction activities will focus on the preparation of the 
walls and floors of the super flood basin to support the placement of 
the monoliths and the construction of the two dry dock positions. The 
primary work needed to prepare the super flood basin involves 
structural reinforcement of the existing berths and floor within the 
super flood basin, bedrock removal, and demolition of portions of the 
super flood basin walls. Most of the preparatory work will occur behind 
the existing super flood basin walls that would act as a barrier to 
sound and would contain underwater noise to within a small portion of 
the Piscataqua River (see Figure 1-3 of the application). Construction 
activities that could affect marine mammals are limited to in-water 
pile driving and removal activities, rock hammering, rotary drilling, 
and down-the-hole (DTH) hammering.
    The construction activities are anticipated to begin in March 2022 
and proceed to March 2023. In-water construction activities would occur 
for 365 days over a period of approximately 12 consecutive months. All 
in-water work capable of producing noise harmful to marine mammals will 
be limited to daylight hours. Pile driving days are not necessarily 
consecutive and certain activities may occur at the same time, 
decreasing the total number of in-water construction days. Vibratory 
pile driving and extraction is assumed to occur during 84 days of Year 
1. Impact pile driving will occur during 24 days in Year 1. DTH 
activities would occur for 919 days and rotary drilling would occur for 
282 days. Rock hammering would occur for 252 days. Overlapping 
activities are estimated to reduce the number of construction days by 
1,172 days for a total of 365 construction days. A total of 539 shafts/
borings; 2,855 holes/anchors; and 422 sheet piles would occur for this 
project.
    Preparatory work for P-381 in Year 1 as proposed for this IHA can 
be generally grouped into four categories: center wall support and tie-
in, structural reinforcement of super flood basin sidewalls and 
entrance, mechanical bedrock removal, and demolition of super flood 
basin wall components. Each category involves one or more activities 
expected to result in harassment of marine mammals.
    A detailed description of the planned project is provided in the 
Federal Register notice for the proposed IHA (87 FR 11860; March 2, 
2022). 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 Response

    A notice of NMFS's proposal to issue an IHA to the Navy was 
published in the Federal Register on March 2, 2022 (87 FR 11860). That 
notice described, in detail, the Navy's activity, the marine mammal 
species that may be affected by the activity, and the anticipated 
effects on marine mammals. During the 30-day public comment period, 
NMFS received no public comment or comment letter from the Marine 
Mammal Commission.

Changes From the Proposed IHA to the Final IHA

    No public comments were received during the comment period; 
however, NMFS made a few minor clarifications and corrections to this 
final notice and the corresponding IHA. In the sections of the 
documents that refer to the use of a bubble curtain, it was established 
that the bubble curtain would be used in cases where the Level A 
harassment zone extends to the full region of influence (ROI). To 
clarify this further, NMFS add that this refers to DTH (cluster and 
mono-hammer), rock hammering, and impact pile driving of sheet piles. 
Specifically, these include the 78-in cluster and 42-in mono DTH, rock 
hammering, and impact pile driving of sheet piles for the secant pile 
guide wall. In addition, for bubble curtains, NMFS clarified that the 
air flow to the bubblers would be balanced across the entrance openings 
to the superflood basin, rather than the piles. Finally, NMFS removed 
the mitigation condition that outlined observers shall work in shifts 
lasting no longer than 4 hours (hrs) with at least a 1-hr break between 
shifts and will not perform duties as a observer for more than 12 hrs 
in a 24-hr period. This is not a required condition for the Navy for 
these construction activities, rather it is related to seismic surveys 
but was accidentally included. That said, NMFS communicated to the Navy 
that observers should be given adequate breaks and work in shifts to 
reduce observer fatigue to ensure their ability to best monitor for 
marine mammals.

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. 
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 with expected potential for occurrence in 
the Piscataqua River in Kittery, Maine, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and ESA and potential biological removal (PBR), where known. 
For taxonomy, NMFS follows Committee on Taxonomy (2021). 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 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 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 Marine Mammal SARs. All values presented in Table 3 
are the most recent available at the time of publication and are 
available in the final 2020 SARs (Hayes et al., 2021) and draft 2021 
SARs, available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports.

[[Page 19888]]



                                    Table 1--Marine Mammals With Potential Presence Within the Proposed Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    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 Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises):
    Harbor porpoise................  Phocoena phocoena.....  Gulf of Maine/Bay of   -; N              95,543...............  851.............        164
                                                              Fundy.                                  (0.31; 74,034; 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harbor seal....................  Phoca vitulina........  Western North          -; N              61,336...............  1,729...........        339
                                                              Atlantic.                               (0.08, 57,637; 2018).
    Gray seal......................  Halichoerus grypus....  Western North          -; N              27,300\4\............  1,389...........      4,453
                                                              Atlantic.                               (0.22; 22,785; 2016).
    Harp seal......................  Pagophilus              Western North          -; N              7,600,000(unk,7,100.0  426,000.........    178,573
                                      groenlandicus.          Atlantic.                                00, 2019).
Hooded seal........................  Cystophora cristata...  Western North          -; N              593,500..............  Unknown.........      1,680
                                                              Atlantic.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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-region#reports. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
\4\ This abundance value and the associated PBR value reflect the US population only. Estimated abundance for the entire Western North Atlantic stock,
  including animals in Canada, is 451,600. The annual M/SI estimate is for the entire stock.

    All species that could potentially occur in the proposed action 
area are included in Table 1. More detailed descriptions of marine 
mammals in the PNSY project area are provided below.
    A detailed description of the species likely to be affected by the 
Navy's 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 (87 FR 
11860; March 2, 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.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the Navy's construction 
activities have the potential to result in Level A and Level B 
harassment by behavioral disturbance, temporary threshold shift to 
marine mammals in the vicinity of the project area. The notice of 
proposed IHA (87 FR 11860; March 2, 2022) included a discussion of the 
effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from the Navy's construction activities 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 (87 FR 11860; 
March 2, 2022).

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of small numbers and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (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 would primarily be by Level B harassment, in the 
form of behavioral disturbance, masking, and potential TTS, with a 
smaller amount of Level A harassment in the form of PTS. As described 
previously, no mortality is anticipated or proposed to be authorized 
for this activity. Below we describe how the take is estimated.
    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 
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 estimate.

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

[[Page 19889]]

factors related to the source (e.g., frequency, predictability, duty 
cycle), the environment (e.g., bathymetry), and the receiving animals 
(hearing, motivation, experience, demography, behavioral context) and 
can be difficult to predict (Southall et al., 2007, Ellison et al., 
2012). Based on what the available science indicates and the practical 
need to use a threshold based on a factor that is both predictable and 
measurable for most activities, NMFS uses a generalized acoustic 
threshold based on received level to estimate the onset of behavioral 
harassment. NMFS predicts that marine mammals are likely to be 
behaviorally harassed in a manner we consider Level B harassment when 
exposed to underwater anthropogenic noise above received levels of 120 
dB re 1 microPascal ([mu]Pa) (root mean square (RMS) for continuous 
(e.g., vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa 
(RMS) for impulsive and/or intermittent (e.g., impact pile driving, 
DTH) sources. The Navy's construction includes the use of continuous 
and impulsive sources, and therefore the 120 and 160 dB re 1 [mu]Pa 
(RMS) thresholds are 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. The 
Navy's modification and expansion of Dry Dock 1 includes the use of 
impulsive (i.e., impact pile driving, DTH) and non-impulsive (i.e., 
drilling, vibratory pile driving) sources.
    These thresholds re provided in Table 2 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.

    Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift for High Frequency Ceteaceans and
                                                    Pinnipeds
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------------
* 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 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]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 (HF cetaceans and PW 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 will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels transmission loss 
coefficient.
    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 * log<INF>10</INF>(R<INF>1</INF>/R<INF>2</INF>),

Where:

B = transmission loss coefficient (assumed to be 15)
R<INF>1</INF> = the distance of the modeled sound pressure level 
(SPL) from the driven pile, and
R<INF>2</INF> = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions, including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log(range)). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log(range)). As is 
common practice in coastal waters, here we assume practical spreading 
(4.5 dB reduction in sound level for each doubling of distance). 
Practical spreading is a compromise that is often used under conditions 
where water depth increases as the receiver moves away from the 
shoreline, resulting in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions. 
Practical spreading was used to determine sound propagation for this 
project.
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. There are sound source 
level (SSL) measurements available for certain pile types and sizes 
from the similar environments from other Navy pile driving projects 
that were evaluated and used as proxy sound source levels to determine 
reasonable sound source levels likely to result from the pile driving 
and removal activities (Table 3). Some of the proxy source levels are 
expected to be more conservative, as the values are from larger pile 
sizes. Acoustic monitoring results and associated monitoring reports 
from past projects conducted at the shipyard and elsewhere were 
reviewed. Projects reviewed were those most similar to the specified 
activity in terms of drilling and rock hammering activities, type and 
size of piles installed, method of pile installation, and substrate 
conditions.

[[Page 19890]]



                                                 Table 3--Summary of In-Water Pile Driving Source Levels
                                                                  [At 10 m from source]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                          SEL (dB re 1
              Pile type                   Installation method          Pile diameter         Peak (dB re 1    RMS (dB re 1 [micro]Pa)    [micro]Pa\ 2\
                                                                                               [micro]Pa)                                     sec)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Casing/Socket........................  Rotary Drill............  102-inch \1\............                 NA  154 m..................                 NA
Shaft................................  DTH Cluster Drill.......  78-inch \2\.............                 NA  195.2 (Level A) 167 dB                 181
                                                                                                               (Level B).
Casing...............................  DTH mono-hammer.........  42-inch \1\.............                194  167....................                164
Rock anchor..........................  DTH mono-hammer.........  9-inch \1\..............                172  167....................                146
Relief hole..........................  DTH mono-hammer.........  4 to 6-inch \1\.........                170  167....................                144
Z-shaped Sheet.......................  Impact..................  28-inch \3\.............                211  196....................                181
                                       Vibratory...............  28-inch \4\.............                 NA  167....................                167
Flat sheet...........................  Vibratory...............  18-inch \5\.............                 NA  163....................                163
Bedrock and concrete demolition......  Rock Hammer \6\ \7\.....  NA......................                197  184....................                175
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Egger 2021a.
\2\ Egger 2021b.
\3\ A proxy value for impact pile driving 28-inch steel sheet piles could not be found so the proxy for a 30-inch steel pipe pile has been used (NAVFAC
  SW 2020 [p. A-4]).
\4\ A proxy value for vibratory pile driving 28-inch steel sheet piles could not be found so a proxy for a 30-inch steel pipe pile has been used (Navy
  2015 [p. 14]).
\5\ NMFS 2019 (p. 24484, Table 5).
\6\ Reyff 2018a
\7\ Reyff 2018b
Notes: All SPLs are unattenuated; dB=decibels; NA = Not applicable; single strike SEL are the proxy sources levels presented for impact pile driving and
  were used to calculate distances to PTS.
dB re 1 [micro]Pa = dB referenced to a pressure of 1 microPascal, measures underwater SPL. dB re 1 [micro]Pa\2\-sec = dB referenced to a pressure of 1
  microPascal squared per second, measures underwater SEL.
All recordings were made at 10 meters unless noted otherwise.

    With regards to the proxy values summarized in Table 3, very little 
information is available regarding source levels for in-water rotary 
drilling activities. As a conservative measure and to be consistent 
with previously issued IHAs for similar projects in the region (Egger 
2021a; Dazey 2012), a proxy of 154 dB RMS is proposed for all rotary 
drilling activities.
    Rock hammering is analyzed as an impulsive noise source. For 
purposes of this analysis, it is assumed that the hammer would have a 
maximum strike rate of 460 strikes per minute and would operate for a 
maximum duration of 15 minutes before needing to reposition or stop to 
check progress. Therefore, noise impacts for rock hammering activities 
are assessed using the number of blows per 15-minute interval (6,900 
blows) and the number of 15-minute intervals anticipated over the 
course of the day based on the durations provided in Table 2-1 and 
Table 6-5 of the application. As with rotary drilling, very little 
information is available regarding source levels associated with 
nearshore rock hammering. Measurements taken for this activity as part 
of the Tappan Zee Bridge replacement project recorded sound levels as 
follows:

<bullet> 197 dBpk, 184 dB RMS, 175 dB SEL (Reyff 2108a, 2018b)

    Since no other comparable proxy values were identified in the 
literature, the Navy is proposing to use the same proxy values for rock 
hammering activities associated with P-381.
    The Navy consulted with NMFS to obtain the appropriate proxy values 
for DTH mono-hammers. With regards to DTH mono-hammers, NMFS provided 
proxy values of 170 dBpk, 167 RMS, and 144 dB single strike SEL for 
holes 8-inches in diameter or less (Reyff 2020); 172 dBpk, 167 RMS, and 
146 dB single strike SEL for holes 8- to 18 inches in diameter (Guan 
and Miner 2020); and 194 dBpk, 167 RMS, and 164 dB single strike SEL 
for holes 24- to 42-inches in diameter (Reyff 2020, Denes et al., 2019 
as cited in NMFS 2021a). For the 78-inch DTH cluster drill, NMFS 
provided an RMS value of 195.2 based off of regression and 
extrapolation calculations of existing data. Because of the high number 
of hammers and strikes for this system, cluster drills were treated as 
a continuous sound source for the time component of Level A harassment 
but still used the impulsive thresholds. The Level B harassment sound 
source level at 10 m remained at 167 dB RMS (Heyvaert and Reyff, 2021 
as cited in NMFS 2021b).
    In conjunction with the NMFS Technical Guidance (2018), in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, NMFS developed a User Spreadsheet that includes 
tools to help predict a simple isopleth that can be used in conjunction 
with marine mammal density or occurrence to help predict takes. We note 
that, because of some of the assumptions included in the methods used 
for these tools, we anticipate that isopleths produced are typically 
going to be overestimates of some degree, which may result in some 
degree of overestimation of Level A harassment take. However, these 
tools offer the best way to predict appropriate isopleths when more 
sophisticated 3D modeling methods are not available, and NMFS continues 
to develop ways to quantitatively refine these tools and will 
qualitatively address the output where appropriate. For stationary 
sources (such as from impact and vibratory pile driving), the NMFS User 
Spreadsheet (2020) predicts the closest distance at which, if a marine 
mammal remained at that distance the whole duration of the activity, it 
would not incur PTS. Inputs used in the User Spreadsheet can be found 
in Appendix A of the Navy's application and the resulting isopleths are 
reported below (Tables 4 and 5).
    Calculated distances to Level A harassment (PTS Onset) and Level B 
harassment thresholds are large, especially for DTH and rock hammering 
activities. However, the full distance of sound propagation would not 
be reached due to the presence of land masses and anthropogenic 
structures that would prevent the noise from reaching nearly the full 
extent of the larger harassment isopleths. The region of influence 
(ROI), which illustrates that the land masses preclude the sound from 
traveling more than approximately

[[Page 19891]]

870 m (3,000 ft) from the source, at most.
    Maximum distances are provided for the behavioral thresholds for 
in-water construction activities. Areas encompassed within the 
threshold (harassment zones) were calculated by using a Geographical 
Information System to clip the maximum calculated distances to the 
extent of the ROI.
    Table 4 summarizes the calculated maximum distances corresponding 
to the underwater marine mammal harassment zones from impulsive (impact 
pile driving, rock hammering, DTH) and Table 5 for non-impulsive noise 
(vibratory pile driving, rotary drilling, etc.) and the area of the 
harassment zone within the ROI. The distances do not take the land 
masses into consideration, but the ensonified areas do. Neither 
consider the reduction that will be achieved by the required use of a 
bubble curtain for certain activities and therefore all take estimates 
are considered conservative. Refer to Figures 6-9 through 6-11 of the 
application for the calculated maximum distances corresponding to the 
underwater marine mammal harassment zones from impulsive (impact pile 
driving, rock hammering, DTH) and non-impulsive noise (vibratory pile 
driving, rotary drilling) and the corresponding area of the harassment 
zone within the ROI.

                              Table 5--Calculated Distance and Areas of Level A and Level B Harassment for Impulsive Noise
                                                  [DTH, impact pile driving, hydraulic rock hammering]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                              Level A harassment (PTS onset) *        Level B harassment
                                                                               Total    --------------------------------------------          *
            Activity                    Purpose          Count and size/     production     High frequency                          --------------------
                                                             duration           days       cetaceans (harbor     Phocid Pinnipeds    Harbor porpoise and
                                                                                               porpoise)                                   phocids
--------------------------------------------------------------------------------------------------------------------------------------------------------
DTH Cluster Drill...............  Foundation Support   38, 78-inch shafts.          247  84,380.4 m/0.417      37,909.7 m/0.417      13,594 m/0.417
                                   Piles for Center                                       km\2\.                km\2\.                km\2\.
                                   Wall.
DTH Cluster Drill...............  Foundation Leveling  18, 78-inch shafts.          117  84,380.4 m/0.417      37,909.7 m/0.417      13,594 m/0.417
                                   Piles for Center                                       km\2\.                km\2\.                km\2\.
                                   Wall.
DTH Cluster Drill...............  Center Wall--Access  38, 78-inch shafts.          133  84,380.4 m/0.417      37,909.7 m/0.417      13,594 m/0.417
                                   Support Platform.                                      km\2\.                km\2\.                km\2\.
DTH Mono-hammer.................  Center Wall--        6, 42-inch shafts..            6  3,880.3 m/0.417       1,743.3 m/0417km\2\.  13,594 m/0.417
                                   Temporary                                              km\2\.                                      km\2\.
                                   Launching Piles.
DTH Mono-hammer.................  Center Wall Tie-     36, 9-inch holes...           18  244.8 m/0.074 km\2\.  110 m/..............  13,594 m/0.417
                                   Downs.                                                                      0.0229 km\2\........   km\2\.
DTH Mono-hammer.................  Center Wall-Access   18, 9-inch holes...            9  244.8 m/0.0741 km\2\  110 m/..............  13,594 m/0.417
                                   Platform Tie-Downs.                                                         0.0229 km\2\........   km\2\.
Impact Pile Driving.............  West Closure Wall    16**, 28-inch Z-            ** 4  988.2 m/0.4034 km\2\  444.0 m/0.2012 km\2\  2,512 m/0.417
                                   Tie-In to Existing   shaped sheets.                                                                km\2\.
                                   Wall.
Impact Pile Driving.............  Berth 11 End Wall    60, 28-inch Z-                 7  1,568.6 m/0.417       704.7 m/0.365 km\2\.  2,512 m/0.417
                                   Secant Pile Guide    shaped sheets.                    km\2\.                                      km\2\.
                                   Wall.
DTH Mono-hammer.................  Relief Holes Under   500, 4-6 inch holes           20  180.1 m/0.0481 km\2\  80.9 m/0.015 km\2\..  13,594 m/
                                   West Closure Cell.                                                                                0. 417km\2\.
DTH Mono-hammer.................  Mechanical Rock      46, 42-inch casing            24  3,880.3 m/0.417       1,743.3 m/0.417       13,594 m/0.417
                                   Removal Along Face   advancements.                     km\2\.                km\2\.                km\2\.
                                   of Existing
                                   Abutment.
DTH Mono-hammer.................  Install Piles for    28, 42-inch shafts.           28  3,880.3 m/0.417       1,743.3 m/0.417       13,594 m/0.417
                                   Dry Dock 1 North                                       km\2\.                km\2\.                km\2\.
                                   Entrance Abutment.
DTH Mono-hammer.................  Relief Holes Under   2,201**, 4-6 inch          ** 82  180.1 m/0.0481km\2\.  80.9 m/0.015 km\2\..  13,594 m/
                                   West Closure Cell.   holes.                                                                       0.417 km\2\.
DTH Mono-hammer.................  Mechanical Rock      365, 42-inch casing          183  3,880.3 m/0.417       1,743.3 m/0.417       13,594 m/
                                   Removal Along Face   advancements.                     km\2\.                km\2\.               0.417 km\2\.
                                   of Existing
                                   Abutment.
DTH Mono-hammer.................  Dry Dock 1 Entrance  100, 9-inch holes..           52  132.9 m/0.0303 km\2\  59.7 m/0.009km\2\...  13,594 m/0.417
                                   Tremie Tie Downs.                                                                                  km\2\.
Impact Pile Driving.............  Install Sheet Piles  96, 28-inch Z-                12  1,568.6 m/0.417       704.7 m/0.365km\2\..  2,512 m/
                                   for Dry Dock 1       shaped sheets.                    km\2\.                                     0.417 km\2\.
                                   North Entrance and
                                   Temporary
                                   Cofferdam.
Hydraulic Rock Hammer...........  Removal of           2.5 hours..........        ** 10  5,860.0 m/0.417       2,633 m/0.4174km\2\.  398 m/
                                   Sheetpile and                                          km\2\.                                     0.165 km\2\.
                                   Granite Quay Wall
                                   (610 cy).
Hydraulic Rock Hammer...........  Mechanical Rock      9 hours............           77  13,766 m/0.417 km\2\  6,184.7 m/0.417       398 m/
                                   Removal (985 cy)                                                             km\2\.               0.165 km\2\.
                                   Under West Closure
                                   Cell.
Hydraulic Rock Hammer...........  Shutter Panel        5 hours............        ** 56  9,303.1 m/0.417       4,179.6 m/0.417       398 m/
                                   Demolition.                                            km\2\.                km\2\.               0.165 km\2\.
Hydraulic Rock Hammer...........  Mechanical Rock      12 hours...........       ** 100  16,676.3 m/0.417      7,492.2 m/0.417       398 m/
                                   Removal (3,500 cy)                                     km\2\.                km\2\.               0.165 km\2\.
                                   Along Face of
                                   Existing Berth 11
                                   at Basin Floor.
Hydraulic Rock Hammer...........  P-310 Sheet Pile     12, 25-inch Z-              ** 3  10,505.4 m/0.417      4,719.8 m/0.417       398 m/
                                   Removal--Berth 1.    shaped sheets, 6                  km\2\.                km\2\.               0.1652 km\2\.
                                                        hours.
Hydraulic Rock Hammer...........  Berth 1 Top of Wall  10 hours...........         ** 6  14,767.7 m/0.417      6,634.7 m/0.417       398 m/
                                   Demolition for                                         km\2\.                km\2\.               0.165km\2\.
                                   Waler Install.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: Kiewit 2021.
Notes:
* To determine underwater harassment zones, ensonified areas from the source were clipped along the shoreline using Geographical Information Systems
  (GIS)
** These activities will continue into the following construction years and the remaining construction days and activities will be included in a
  subsequent LOA. The construction days and activities represented in this table account ONLY for year 1 activities
lf = linear feet; N/A = Not Applicable
Proxy sources used were unattenuated SPLs.


[[Page 19892]]


                            Table 5--Calculated Distance and Areas of Level A and Level B Harassment for Non-Impulsive Noise
                                                        [vibratory pile driving, rotary drilling]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Level A Harassment  (PTS Onset)        Level B Harassment
                                                                               Total    ----------------------------------------------------------------
            Activity                    Purpose           Count and size     production     High frequency
                                                                                days       cetaceans harbor      Phocid Pinnipeds    Harbor porpoise and
                                                                                               porpoise                                    phocids
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rotary Drill....................  Center Wall          38, 102-inch                  38  2.1 m/0.000014 km\2\  1.3 m/0.000005 km\2\  1,848 m/
                                   Foundation Pile--    Borings.                                                                     0.417
                                   Install Outer                                                                                     km\2\
                                   Casing.
Rotary Drill....................  Center Wall          38, 102-inch                  38  8.9 m/0.000248 km\2\  5.4 m/0.000091 km\2\  1,848 m/
                                   Foundation Pile--    Borings.                                                                     0.417
                                   Pre-Drill Socket.                                                                                 km\2\
Rotary Drill....................  Center Wall          38, 102-inch                  38  0.8 m/0.000002 km\2\  0.5 m/0.000001 km\2\  1,848 m/
                                   Foundation Pile--    Borings.                                                                     0.417
                                   Remove Outer                                                                                      km\2\
                                   Casing.
Rotary Drill....................  Center Wall          18, 102-inch                  18  2.1 m/..............  1.3 m/0.000005 km\2\  1,848 m/
                                   Leveling Piles--     Borings.                         0.000014 km\2\......                        0.417
                                   Install Outer                                                                                     km\2\
                                   Casing.
Rotary Drill....................  Center Wall          18, 102-inch                  18  8.9 m/..............  5.4 m/0.000091 km\2\  1,848 m/
                                   Leveling Piles--     Borings.                         0.000248 km\2\......                        0.417
                                   Pre-Drill Socket.                                                                                 km\2\
Rotary Drill....................  Center Wall          18, 102-inch                  18  0.8 m/..............  0.5 m/0.000001 km\2\  1,848 m/
                                   Leveling Piles--     Borings.                         0.000002 km\2\......                        0.417
                                   Remove Outer                                                                                      km\2\
                                   Casing.
Rotary Drill....................  Center Wall Access   38, 102-inch                  38  2.1 m/..............  1.3 m/0.000005 km\2\  1,848 m/
                                   Platform Support--   Borings.                         0.000014 km\2\......                        0.417
                                   Install Outer                                                                                     km\2\
                                   Casing.
Rotary Drill....................  Center Wall Access   38, 102-inch                  38  8.9 m/..............  5.4 m/0.000091 km\2\  1,848 m/
                                   Platform Support--   Borings.                         0.000248 km\2\......                        0.417
                                   Pre-Drill Socket.                                                                                 km\2\
Rotary Drill....................  Center Wall Access   38, 102-inch                  38  0.8 m/..............  0.5 m/0.000001 km\2\  1,848 m/
                                   Platform Support--   Borings.                         0.000002 km\2\......                        0.417
                                   Remove Outer                                                                                      km\2\
                                   Casing.
Vibratory Pile Driving..........  Tie-In to Existing   16**, 28-inch Z-            ** 4  12.2 m/.............  5.0 m/0.000078 km\2\  13,594 m/
                                   West Closure Wall.   Shaped Sheets.                   0.000454 km\2\......                        0.417 km\2\
Vibratory Pile Driving..........  Berth 11 End Wall    60, 28-inch Z-                 7  19.4 m/.............  8.0 m/0.0002 km\2\..  13,594 m/
                                   Secant Pile Guide    Shaped Sheets.                   0.001041 km\2\......                        0.417 km\2\
                                   Wall.
Vibratory Extraction............  Remove P-310 West    238, 18-inch Flat             60  6.6 m/..............  2.7 m/0.000023 km\2\  7,356 m/
                                   Closure Wall.        Sheets.                          0.000136 km\2\......                        0.417 km\2\
Vibratory Pile Driving..........  Install Sheet Piles  96, 28-inch Z-                12  19.4 m/.............  8.0 m/..............  13,594 m/
                                   for Dry Dock 1       Shaped Sheets.                   0.001041 km\2\......  0.0002 km\2\........  0.417 km\2\
                                   North Entrance and
                                   Temporary
                                   Cofferdam.
--------------------------------------------------------------------------------------------------------------------------------------------------------
** These activities will continue into the following construction years and the remaining construction days and activities will be included in a
  subsequent LOA. The construction days and activities represented in this table account ONLY for year 1 activities.
lf = linear feet; N/A = Not Applicable.
Proxy sources used were unattenuated SPLs.

Concurrent Activities
    Simultaneous use of pile drivers, hammers, and drills could result 
in increased SPLs and harassment zone sizes given the proximity of the 
component sites and the rules of decibel addition (see Table 6 below). 
Due to the relatively small size of the ROI, the use of a single DTH 
cluster drill or rock hammer would ensonify the entire ROI to the Level 
A harassment thresholds (PTS Onset) (refer to Table 4). Therefore, when 
this equipment is operated in conjunction with other noise generating 
equipment, there would be no change in the size of the harassment zone. 
The entire ROI would remain ensonified to the Level A harassment 
thresholds for the duration of the activity and there would be no Level 
B harassment zone. However, when DTH cluster drills or rock hammers are 
not in use, increased SPLs and harassment zone sizes within the ROI 
could result. Due to the large amount of bedrock excavation required 
for the construction of the multifunctional expansion of Dry Dock 1, 
the only scenario identified in which DTH cluster drills and/or rock 
hammers would not be in operation would be at the beginning of the 
project when two rotary drills could be used simultaneously.
    According to recent, project specific, guidance provided by NMFS to 
the Navy, when two noise sources have overlapping sound fields, there 
is potential for higher sound levels than for non-overlapping sources 
because the isopleth of one sound source encompasses the sound source 
of another isopleth. In such instances, the sources are considered 
additive and combined using the rules of decibel addition, presented in 
Table 6 below.

         Table 6--Adjustments for Sound Exposure Level Criterion
------------------------------------------------------------------------
                                                       Adjustments to
                               Difference in sound   specifications for
        Source types           level (at specified   Level A harassment
                                     meters)             RMS/SELss*
                                                        calculations
------------------------------------------------------------------------
Non-impulsive, continuous/    0 or 1 dB...........  Add 3 dB to the
 Non-impulsive, continuous                           highest sound level
 OR Impulsive source                                 (at specified
 (multiple strikes per                               meters) AND adjust
 second)/Impulsive source                            number of piles per
 (multiple strikes per                               day to account for
 second).                                            overlap (space and
                                                     time).

[[Page 19893]]

 
                              2 or 3 dB...........  Add 2 dB to the
                                                     highest sound level
                                                     (at specified
                                                     meters) AND adjust
                                                     number of piles per
                                                     day to account for
                                                     overlap (space and
                                                     time).
                              4 to 9 dB...........  Add 1 dB to the
                                                     highest sound level
                                                     (at specified
                                                     meters) AND adjust
                                                     number of piles per
                                                     day to account for
                                                     overlap (space and
                                                     time).
                              10 dB or more.......  Add 0 dB to the
                                                     highest sound level
                                                     (at specified
                                                     meters) AND adjust
                                                     number of piles per
                                                     day to account for
                                                     overlap (space and
                                                     time).
------------------------------------------------------------------------
* RMS level for vibratory pile driving/rotary hammer and single strike
  SEL (SELss) level for DTH/rock hammer.

    For simultaneous usage of three or more continuous sound sources, 
the three overlapping sources with the highest sound source levels are 
identified. Of the three highest sound source levels, the lower two are 
combined using the above rules, then the combination of the lower two 
is combined with the highest of the three. For example, with 
overlapping isopleths from 24-, 36-, and 42-inch diameter steel pipe 
piles with sound source levels of 161, 167, and 168 dB RMS 
respectively, the 24- and 36-inch would be added together; given that 
167-161 = 6 dB, then 1 dB is added to the highest of the two sound 
source levels (167 dB), for a combined noise level of 168 dB. Next, the 
newly calculated 168 dB is added to the 42-inch steel pile with sound 
source levels of 168 dB. Since 168-168 = 0 dB, 3 dB is added to the 
highest value, or 171 dB in total for the combination of 24-, 36-, and 
42-inch steel pipe piles (NMFS, 2021 unpublished). By using this 
method, a revised proxy source for Level A and Level B analysis was 
determined for the use of two, 102-inch diameter rotary drills. The 
revised proxy value is presented in Table 7 and the resulting 
harassment zones are summarized in Table 8 (depicted in Figure 6-13 in 
the Navy's application).

   Table 7--Revised Proxy Values for Simultaneous Use of Non-Impulsive
                                 Sources
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Equipment                                                         Rotary
                                                                   drill
------------------------------------------------------------------------
                                       RMS                           154
------------------------------------------------------------------------
Rotary Drill.........................  154                           157
------------------------------------------------------------------------


   Table 8--Level A and Level B Harassment Zones Resulting From the Simultaneous Use of Two, 102-In. Diameter
                                                  Rotary Drill
----------------------------------------------------------------------------------------------------------------
                                                Level A harassment (PTS onset)              Level B harassment
                                      --------------------------------------------------------------------------
                                           Harbor porpoise                                 Harbor porpoise and
       Multiple source scenario           distance to 155 dB    Phocids distance to 185  phocids distance to 120
                                        SELcum threshold/area     dB SELcum threshold/   dB (DTH) threshold/area
                                          of harassment zone    area of harassment zone     of harassment zone
----------------------------------------------------------------------------------------------------------------
2 Rotary Drills......................  23.6 m/0.002 km\2\.....  9.7 m/0.0002 km\2\.....  2,929 m/0.417 km\2\
----------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. Potential exposures to impact pile and vibratory pile 
driving, rotary drilling, DTH, and rock hammering noise for each 
acoustic threshold were estimated using marine mammal density estimates 
(N) from the Navy Marine Species Density Database (NMSDD) (Navy 2017) 
or from monitoring reports from the Berth 11 Waterfront Improvements 
and P-310 construction projects. Specifically, where monitoring data 
specific to the project area were available, they were used, and the 
NMSDD data were used when there were no monitoring data available. The 
take estimate was determined using the following equation take estimate 
= N * days of activity * area of harassment. The pile type, size, and 
installation method that produce the largest zone of influence (ZOI) 
were used to estimate exposure of marine mammals to noise impacts. We 
describe how the information provided above is brought together to 
produce a quantitative take estimate in the species sections below.
Harbor Porpoise
    Harbor porpoises may be present in the proposed project area during 
spring, summer, and fall, from April to December. Based on density data 
from the Navy Marine Species Density Database, their presence is 
highest in spring, decreases in summer, and slightly increases in fall. 
During previous monitoring of construction projects in the area, three 
harbor porpoise were sighted between April and December of 2017; two 
harbor porpoise were sighted in early August of 2018; and one harbor 
porpoise was sighted in 2020 (Cianbro 2018a, b; Navy 2019; NAVFAC 
2021). Using the 2017 and 2018 data from construction monitoring for 
the Berth 11 Waterfront Improvements project, the density of harbor 
porpoise for the largest harassment zone was determined to be 0.04/
km\2\.
    Estimated take was calculated by density * harassment zone * days 
for each activity (see Table 9). Note that where the Level A harassment 
zone is as large as the Level B harassment zone and fills the entire 
ensonified area, the enumerated takes in the Level A harassment column 
may be in the form of Level A harassment and/or Level B harassment.

[[Page 19894]]



                       Table 9--Calculated Proposed Take by Level A and Level B Harassment of Harbor Porpoise by Project Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Level A                                         Level B
                    Project activity                          Density       harassment    Number of days   Take by Level    harassment     Take by Level
                                                                           zone  (km\2\)                   A harassment    zone  (km\2\)   B harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Center Wall--Install Foundation: 38 drilled shafts:                 0.04           0.417             247               4           0.417               0
 Cluster drill DTH (Drill) 78-inch diameter casing......
Center Wall--Install Diving Board Shafts: 18 drilled                0.04           0.417             117               2           0.417               0
 shafts: Cluster drill DTH (Drill) 78-inch diameter
 socket.................................................
Center Wall--Access Platform Support: 38 drilled shafts:            0.04           0.417             133               2           0.417               0
 Cluster Drill DTH (Drill) 78-inch outer casing.........
Mechanical Rock Excavation, Hydraulic rock hammering                0.04           0.417              77               1           0.165               0
 (985 cy)...............................................
Remove Shutter Panels: 112 panels, Demolish shutter                 0.04           0.417              56               1           0.165               0
 panels, Hydraulic rock hammering.......................
Mechanical Rock Removal at Basin Floor: Excavate                    0.04           0.417             100               2           0.165               0
 Bedrock, Hydraulic rock hammering......................
Mechanical Rock at Abutment: Drill 365 rock borings                 0.04           0.417             183               3           0.417               0
 (1,220 cy), 42-inch diameter casing, Mono-hammer DTH...
Center Wall--Install Foundation: 38 drilled shafts:                 0.04         0.00001              38               0           0.417               1
 Rotary Drill (Install) 102-inch diameter outer casing..
Center Wall--Install Foundation: 38 drilled shafts:                 0.04         0.00001              38               0           0.417               1
 Rotary Drill (Pre-drill) 102-inch diameter socket,.....
Center Wall--Install Foundation: 38 drilled shafts:                 0.04         0.00001              38               0           0.417               1
 Rotary Drill (Remove) 102-inch outer casing............
Center Wall--Access Platform Support: 38 drilled shafts:            0.04         0.00001              38               0           0.417               1
 Rotary Drill (Install) 102-inch diameter outer casing..
Center Wall--Access Platform Support: 38 drilled shafts:            0.04         0.00001              38               0           0.417               1
 Rotary Drill (Pre-drill) 102-inch diameter socket......
Center Wall--Access Platform Support: 38 drilled shafts:            0.04       0.0000002              38               0           0.417               1
 Rotary Drill (Remove) 102-inch outer casing,...........
Remove Wall: 238 sheet piles, 18-inch wide flatwebbed,              0.04        0.000136              60               0           0.417               1
 Vibratory Extraction...................................
Mechanical Rock Removal at Basin Floor: Drill 2,201                 0.04        0.048109              82               0           0.417               1
 relief holes, 4-6 holes, Mono-hammer DTH,..............
Drill Tremie Ties Downs: Drill 100 rock anchors, 9-inch             0.04          0.0303              52               0           0.417               1
 holes, Mono-hammer DTH.................................
                                                         -----------------------------------------------------------------------------------------------
    Total Estimated Take................................  ..............  ..............  ..............              15  ..............               9
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In summary, we estimate that up to 15 takes in the form of Level A 
harassment and/or Level B harassment could occur during DTH excavation 
(DTH mono-hammer and cluster drill), impact pile driving, and rock 
hammering activities. In addition, DTH mono-hammer excavation could 
result in 2 takes by Level B harassment and vibratory installing/
extracting and rotary drilling activities could result in 7 takes by 
Level B harassment (Table 9).
Harbor Seal
    Harbor seals may be present year-round in the project vicinity, 
with constant densities throughout the year. Harbor seals are the most 
common pinniped in the Piscataqua River near the Shipyard. Harbor seal 
sightings were recorded during monthly surveys conducted in 2017 and 
2018 (NAVFAC Mid-Atlantic 2018, 2019b) as well as during Berth 11 and 
P-310 construction monitoring in 2017, 2018, 2020 and 2021 (Cianbro 
2018a, b; Navy 2019; Stantec 2020, Stantec 2021). Estimated take by 
Level B harassment has been calculated by multiplying the average 
number of harbor seals sighted per day from May 2020 through October 
2021 by the number of actual in-water construction days (375 days (159 
during P-310 year 1 and 216 during P-310 year 2). Over the course of 
this time period, there have been 1,023 harbor seal observations 
equating to equating to 3 harbor seal sightings per day. Initially, 
takes were calculated for Level A and Level B harassment for harbor 
seals where the density of animals (2.48 harbor seals/km\2\, rounded to 
3) was multiplied by the harassment zone and the number of days per 
construction activity. However, using that method produced take numbers 
for Level B harassment that were lower than the number of harbor seals 
that has been previously observed in the Navy's monitoring reports. 
Therefore, NMFS is proposing (and the Navy agrees), to increase the 
take by Level B harassment to more accurately reflect harbor seal 
observations in the monitoring reports, by using the value of three 
harbor seals a day multiplied by the total number of construction days 
resulting in 1,125 takes by Level B harassment proposed for 
authorization. Take by Level A harassment of 1,269 harbor seals is 
shown in Table 10 below. Note that where the Level A harassment zone is 
as large as the Level B harassment zone and fills the entire ensonified 
area, the enumerated takes in the Level A harassment column may be in 
the form of Level A harassment and/or Level B harassment. The 
authorized takes by Level B harassment were not included in Table 10 as 
they were calculated by a different method discussed above.

[[Page 19895]]



           Table 10--Calculated Proposed Take by Level A Harassment of Harbor Seal by Project Activity
----------------------------------------------------------------------------------------------------------------
                                                                      Level A
                Project activity                   Harbor seals     harassment    Number of days  Take by  Level
                                                      density      zone  (km\2\)                   A  harassment
----------------------------------------------------------------------------------------------------------------
Center Wall--Install Foundation: 38 drilled                    3           0.417             247             309
 shafts: Cluster drill DTH (Drill) 78-inch
 diameter casing................................
Center Wall--Install Diving Board Shafts: 18                   3           0.417             117             146
 drilled shafts: Cluster drill DTH (Drill) 78-
 inch diameter socket...........................
Center Wall--Access Platform Support: 38 drilled               3           0.417             133             166
 shafts: Cluster Drill DTH (Drill) 78-inch outer
 casing.........................................
Center Wall--Temp Launching Piles: 6 drilled                   3           0.417               6               8
 shafts: 42-inch diameter shaft, Mono-hammer DTH
Center Wall Tie Downs: 36 Rock Anchors                         3           0.023              18               1
 (Install): 9-inch diameter holes, Mono-hammer
 DTH............................................
Center Wall--Access Platform Tie Downs: 18 Rock                3           0.023               9               1
 Anchors (Install): 9-inch diameter holes, Mono-
 hammer DTH.....................................
Center Wall--Install Tie-In to Existing West                   3           0.201               4               2
 Closure Wall: 16 sheet piles: 28-inch wide Z-
 shaped sheets--IMPACT Install..................
Berth 11 End Wall--Install Secant Pile Guide                   3           0.417               7               8
 Wall: 60 sheets piles: 28-inch wide Z-shaped
 sheets--IMPACT Install.........................
Berth 1--Remove Granite Block Quay Wall: 610 cy,               3           0.417              10              13
 Granite block demo, Hydraulic Rock hammering...
P310 West Closure Wall--Mechanical Rock                        3           0.417              77              96
 Excavation: 985 cy, Excavated bedrock,
 Hydraulic rock hammering.......................
P310 West Closure Wall--Mechanical Rock                        3           0.015              20               1
 Excavation: Drill 500 relief holes, 4-6 inch
 holes, Mono-hammer DTH.........................
P310 West Closure Wall--Mechanical Rock                        3           0.417              24              30
 Excavation: Drill 46 rock borings (50 cy), 42-
 inch diameter casing, Mono-hammer DTH..........
West Closure well--Berth 11 Abutment--Install                  3           0.417              28              35
 Piles: Drill 28 shafts, 42-inch diameter
 casing, Mono-hammer DTH........................
Berth 11--Remove Shutter Panels: 112 panels,                   3           0.417              56              70
 Demolish shutter panels, Hydraulic rock
 hammering......................................
Berth 11 Face--Mechanical Rock Removal at Basin                3           0.417             100             125
 Floor: 3,500 cy, Excavate Bedrock, Hydraulic
 rock hammering.................................
Berth 11 Face--Mechanical Rock Removal at Basin                3           0.015              82               4
 Floor: Drill 2,201 relief holes, 4-6 holes,
 Mono-hammer DTH................................
Berth 11 Face--Mechanical Rock at Abutment:                    3           0.417             183             229
 Drill 365 rock borings (1,220 cy), 42-inch
 diameter casing, Mono-hammer DTH...............
Dry Dock 1 North Entrances--Install Temporary                  3           0.365              12              13
 Cofferdam: Install 96 sheet piles, 28-inch wide
 Z-shaped sheets, IMPACT Install................
Berth 1--Remove sheet piles: Remove 12 sheet                   3           0.417               3               4
 piles, 25-inch wide Z-shaped sheets, Hydraulic
 rock hammering.................................
Berth 1 Top of Wall--Demolition for Waler                      3           0.417               6               8
 Installation: 30 lf, Mechanical concrete
 demolition, Hydraulic rock hammering...........
                                                 ---------------------------------------------------------------
    Total Estimated Take........................  ..............  ..............  ..............           1,269
----------------------------------------------------------------------------------------------------------------

Gray Seal
    Gray seals may be present year-round in the project vicinity, with 
constant densities throughout the year. Gray seals are less common in 
the Piscataqua River than the harbor seal. Sightings of gray seals were 
recorded during P-310 construction monitoring in 2020 and 2021 (Stantec 
2020; Stantec 2021). Estimated take by Level B harassment has been 
calculated by multiplying the average number of gray seal observations 
per day from May 2020 through October 2021 (47 during year 1 P-310 
monitoring and 9 during year 2 P-310 monitoring (to date)) over the 
course of 337 monitoring days (Stantec 2020; 2021). Over the course of 
this time period, there have been 56 gray seal observations equating to 
equating to 0.2 gray seal sightings per day. Initially, takes were 
calculated for Level A and Level B harassment for gray seals where the 
density was multiplied by the harassment zone and the number of days 
per construction activity. However, using that method produced take 
numbers for Level B harassment that were fewer than the number of gray 
seals that has been previously observed in the Navy's monitoring 
reports. Therefore, NMFS (and the Navy agreed) increased the take by 
Level B harassment to more accurately reflect gray seal observations in 
the monitoring reports, by using the value of 0.2 gray seals multiplied 
by the total number of construction days resulting in 75 takes by Level 
B harassment. Take by Level A harassment of 85 gray seals is shown in 
Table 11 below. Note that where the Level A harassment zone is as large 
as the Level B harassment zone and fills the entire ensonified area, 
the enumerated takes in the Level A harassment column may be in the 
form of Level A harassment and/or Level B harassment. The authorized 
takes by Level B harassment were not included in Table 11 as they were 
calculated by a different method as discussed above.

[[Page 19896]]



            Table 11--Calculated Proposed Take by Level A Harassment of Gray Seal by Project Activity
----------------------------------------------------------------------------------------------------------------
                                                                      Level A
                Project activity                     Gray seal      harassment    Number of days   Take by Level
                                                      density       zone (km2)                     A harassment
----------------------------------------------------------------------------------------------------------------
Center Wall--Install Foundation: 38 drilled                  0.2           0.417             247              21
 shafts: Cluster drill DTH (Drill) 78-inch
 diameter casing................................
Center Wall--Install Diving Board Shafts: 18                 0.2           0.417             117              10
 drilled shafts: Cluster drill DTH (Drill) 78-
 inch diameter socket...........................
Center Wall--Access Platform Support: 38 drilled             0.2           0.417             133              11
 shafts: Cluster Drill DTH (Drill) 78-inch outer
 casing.........................................
Center Wall--Temp Launching Piles: 6 drilled                 0.2           0.417               6               1
 shafts: 42-inch diameter shaft, Mono-hammer DTH
Berth 11 End Wall--Install Secant Pile Guide                 0.2           0.417               7               1
 Wall: 60 sheets piles: 28-inch wide Z-shaped
 sheets--IMPACT Install.........................
Berth 1--Remove Granite Block Quay Wall: 610 cy,             0.2           0.417              10               1
 Granite block demo, Hydraulic Rock hammering...
P310 West Closure Wall--Mechanical Rock                      0.2           0.417              77               6
 Excavation: 985 cy, Excavated bedrock,
 Hydraulic rock hammering.......................
P310 West Closure Wall--Mechanical Rock                      0.2           0.417              24               2
 Excavation: Drill 19 rock borings (50 cy), 42-
 inch diameter casing, Mono-hammer DTH..........
West Closure well--Berth 11 Abutment- Install                0.2           0.417              28               2
 Piles: Drill 28 shafts, 42-inch diameter
 casing, Mono-hammer DTH........................
Berth 11--Remove Shutter Panels: 112 panels,                 0.2           0.417              56               5
 Demolish shutter panels, Hydraulic rock
 hammering......................................
Berth 11 Face--Mechanical Rock Removal at Basin              0.2           0.417               3               8
 Floor: 1,020 cy, Excavate Bedrock, Hydraulic
 rock hammering.................................
Berth 11 Face--Mechanical Rock at Abutment:                  0.2           0.417              24              15
 Drill 192 rock borings (610 cy), 42-inch
 diameter casing, Mono-hammer DTH...............
Dry Dock 1 North Entrances--Install Temporary                0.2           0.365              12               1
 Cofferdam: Install 96 sheet piles, 28-inch wide
 Z-shaped sheets, IMPACT Install................
Berth 1 Top of Wall--Demolition for Waler                    0.2           0.417               6               1
 Installation: 30 lf, Mechanical concrete
 demolition, Hydraulic rock hammering...........
                                                 ---------------------------------------------------------------
    Total Estimated Take........................  ..............  ..............  ..............              85
----------------------------------------------------------------------------------------------------------------

Hooded Seal
    Hooded seals may be present in the project vicinity from January 
through May, though their exact seasonal densities are unknown. In 
general, hooded seals are much rarer than the harbor seal and gray seal 
in the Piscataqua River. One take per month from January to May from 
Level B harassment of a hooded seal for the Berth 11 Waterfront 
Improvements Construction project (NMFS 2018b) and for Year 1 
construction activities for Dry Dock 1 (NMFS, 2019) was previously 
authorized. To date, the monitoring for that project and for the 
density surveys have not recorded a sighting of hooded seal in the 
project area (Cianbro 2018a, b; NAVFAC Mid-Atlantic 2018, 2019b; Navy 
2019; Stantec 2020; Stantec 2021). In order to guard against 
unauthorized take, the Navy requested and NMFS is authorizing one take 
by Level B harassment of hooded seal per month (between the months of 
January and May) resulting in five total takes of Level B harassment. 
No take by Level A harassment is anticipated or authorized.
Harp Seal
    Harp seals may be present in the project vicinity January through 
May. In general, harp seals are much rarer than the harbor seal and 
gray seal in the Piscataqua River. As discussed above for hooded seals, 
one take by Level B harassment during each month of construction for 
the Berth 11 Waterfront Improvements Project (NMFS 2018b) and for year 
1 construction activities for Dry Dock 1 (NMFS, 2019) was previously 
authorized. The monitoring for the Berth 11 Waterfront Improvements 
Construction and P-310 projects did not record any sightings of harp 
seal in the project area (Cianbro 2018a, b; NAVFAC Mid-Atlantic 2018, 
2019b; Navy 2019; Stantec 2020; Stantec 2021). However, it should be 
noted that two harp seals (one on 5/12/2020 and one on 5/14/2020) were 
observed when pile driving activities were not occurring (Stantec 
2020). In order to guard against unauthorized take, the Navy requested 
and NMFS is authorizing one take by Level B harassment of harp seal per 
month (between the months of January and May) resulting in five total 
takes of Level B harassment. No take by Level A harassment is 
anticipated or authorized.
    Table 12 below summarizes the authorized take for all the species 
described above as a percentage of stock abundance.

                      Table 12--Proposed Take Estimates as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                    Proposed Level  Proposed Level
            Species                 Stock (NEST)     A harassment    B harassment         Percent of stock
----------------------------------------------------------------------------------------------------------------
Harbor porpoise................  Gulf of Maine/Bay              15               9  Less than 1 percent.
                                  of Fundy
                                  (95,543).
Harbor seal....................  Western North               1,269           1,125  Less than 3 percent.
                                  Atlantic
                                  (61,336).
Gray seal......................  Western North                  85              75  Less than 1 percent.
                                  Atlantic
                                  (451,600).
Hooded seal....................  Western North                   0               5  Less than 1 percent.
                                  Atlantic
                                  (593,500).

[[Page 19897]]

 
Harp seal......................  Western North                   0               5  Less than 1 percent.
                                  Atlantic (7.6
                                  million).
----------------------------------------------------------------------------------------------------------------

Mitigation

    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, 
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, we carefully consider 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, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means 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.

General

    The Navy will follow mitigation procedures as described below. In 
general, if poor environmental conditions restrict full visibility of 
the shutdown zone, pile driving activities would be delayed.

Training

    The Navy will ensure that construction supervisors and crews, the 
monitoring team, and relevant Navy staff are trained and prior to the 
start of construction activity, so that responsibilities, communication 
procedures, monitoring protocols, and operational procedures are 
clearly understood. New personnel joining during the project shall be 
trained prior to commencing work.

Avoiding Direct Physical Interaction

    The Navy will avoid direct physical interaction with marine mammals 
during construction activity. If a marine mammal comes within 10 m of 
such activity, operations will cease and vessels will reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions, as necessary to avoid direct physical interaction.

Shutdown Zones

    The Navy will establish shutdown zones for all pile driving 
activities. The purpose of a shutdown zone is generally to define an 
area within which shutdown of the activity would occur upon sighting of 
a marine mammal (or in anticipation of an animal entering the defined 
area). Shutdown zones will vary based on the activity type and marine 
mammal hearing group (Table 13).

               Table 13--Pile Driving Shutdown Zone and Monitoring Zones During Project Activities
----------------------------------------------------------------------------------------------------------------
                                                     Shutdown zone  (m)
                                              -------------------------------- Level B harassment \1\ monitoring
      P-381 year 1 activity description            Harbor                                  zone  (m)
                                                  porpoise         Phocids
----------------------------------------------------------------------------------------------------------------
78-inch cluster drill........................         \2\ 200          \2\ 50  ROI
DTH monohammer--42-inch......................         \2\ 200          \2\ 50  ROI
DTH monohammer--9-inch Center wall tie downs.         \2\ 200          \2\ 50  ROI
DTH monohammer--9-inch tremie tie-downs......         \2\ 200          \2\ 50  ROI
DTH monohammer--4-6-inch (500)...............         \2\ 200          \2\ 50  ROI
Impact install of sheet piles (16) West               \2\ 200          \2\ 50  ROI
 Closure Wall Tie-in.
Impact install of sheet piles (60) Secant             \2\ 200          \2\ 50  ROI
 pile guide wall; (96) temporary coffer dam.
Rock hammering--all durations................         \2\ 200          \2\ 50  ROI
Rotary drilling--Install 102-inch casing.....              10              10  ROI
Rotary drilling--Predrill 102-inch socket....              10              10  ROI
Rotary drilling--Remove 102-inch casing......              10              10  ROI
Vibratory pile driving (16) 28-inch sheets...              20              10  ROI
Vibratory pile driving (60) and (96) 28-inch               20              10  ROI
 sheets.
Vibratory extraction (238) 28-inch sheets....              10              10  ROI
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ In instances where the harassment zone is larger than the ROI, the entire ROI is indicated as the limit of
  monitoring.
\2\ Reduced Monitoring area distance negotiated with NMFS.
Key: ROI--region of influence.


[[Page 19898]]

Soft Start

    The Navy will use soft start techniques when impact pile driving. 
Soft start requires contractors to provide an initial set of three 
strikes from the hammer at reduced energy, followed by a 30-second 
waiting period. Then two subsequent reduced-energy strike sets would 
occur. A 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.

Bubble Curtain

    A bubble curtain will be installed across any openings at the 
entrance of super flood basin to attenuate sound for the sound sources 
that encompass the entire ROI, which include during DTH excavation (DTH 
mono-hammer and cluster drill), hydraulic rock hammering and impact 
pile driving of sheet piles. The Navy will record hydroacoustic 
measurements inside and outside of the bubble curtain. Should the 
results of the recordings inside the bubble curtain show that 
thresholds are not being exceeded by the activity occurring, that upon 
review of the data by NMFS, Navy may discontinue use of the bubble 
curtain for those activities that are not actually exceeding 
thresholds.
    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the mitigation measures provide the 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.

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 in the 
action area. Effective reporting is critical both to compliance as well 
as for 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:
    [ssquf] Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    [ssquf] Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    [ssquf] Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    [ssquf] How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    [ssquf] Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    [ssquf] Mitigation and monitoring effectiveness.
    The Navy will submit a Marine Mammal Monitoring Plan to NMFS for 
approval in advance of the start of construction.

Monitoring Zones

    The Navy will conduct monitoring to include the area within the 
Level B harassment zones (areas where SPLs are equal to or exceed the 
160 dB RMS threshold for impact driving and the 120 dB RMS threshold 
during vibratory pile driving) (see Table 13 above). These monitoring 
zones provide utility for monitoring conducted for mitigation purposes 
(i.e., shutdown zone monitoring) by establishing monitoring protocols 
for areas adjacent to the shutdown zones. Monitoring of the disturbance 
zones enables observers to be aware of and communicate the presence of 
marine mammals in the project area, but outside the shutdown zone, and 
thus prepare for potential shutdowns of activity.

Visual Monitoring

    Monitoring will take place from 30 minutes (min) prior to 
initiation of pile driving activity (i.e., pre-start clearance 
monitoring) through 30 min post-completion of pile driving activity. If 
a marine mammal is observed entering or within the shutdown zones, pile 
driving will 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 min have passed 
without re-detection of the animal. Pile driving activity will be 
halted upon observation of either 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 disturbance zone.

Protected Species Observer (PSO) Monitoring Requirements and Locations

    PSOs will be responsible for monitoring, the shutdown zones, the 
disturbance zones and the pre-clearance zones, as well as effectively 
documenting Level A and B harassment take. As described in more detail 
in the Reporting section below, they will also (1) document the 
frequency at which marine mammals are present in the project area, (2) 
document behavior and group composition, (3) record all construction 
activities, and (4) document observed reactions (changes in behavior or 
movement) of marine mammals during each sighting. The PSOs will monitor 
for marine mammals during all in-water pile activities associated with 
the project. The Navy shall monitor the project area to the extent 
possible based on the required number of PSOs, required monitoring 
locations, and environmental conditions. Visual monitoring shall be 
conducted by three PSOs. It is assumed that three PSOs shall be located 
on boats, docks, or piers sufficient to monitor the respective ROIs 
given the abundance of suitable vantage points (see Figure 11-1 of the 
application). The PSOs must record all observations of marine mammals, 
regardless of distance from the pile being driven.
    Monitoring of pile driving will be conducted by qualified, PSOs. 
The Navy shall adhere to the following conditions when selecting PSOs:
    [ssquf] PSOs must be independent (i.e., not construction personnel) 
and have no other assigned tasks during monitoring periods;
    [ssquf] At least one PSO must have prior experience performing the 
duties of a PSO during construction activities pursuant to a NMFS-
issued incidental take authorization;
    [ssquf] Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field), or training;

[[Page 19899]]

    [ssquf] Where a team of three PSOs are required, a lead observer or 
monitoring coordinator shall be designated. The lead observer must have 
prior experience performing the duties of a PSO during construction 
activity pursuant to a NMFS-issued incidental take authorization; and
    The Navy will ensure that the PSOs have the following additional 
qualifications:
    [ssquf] Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    [ssquf] Experience and ability to conduct field observations and 
collect data according to assigned protocols;
    [ssquf] Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    [ssquf] Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    [ssquf] 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
    [ssquf] 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.

Hydroacoustic Monitoring

    The Navy will conduct a sound source verification (SSV) study for 
all pile types and will follow accepted methodological standards to 
achieve their objectives. The Navy will submit an acoustic monitoring 
plan to NMFS for approval prior to the start of construction. The Navy 
will collect and evaluate acoustic sound record levels for 10 percent 
of the new rotary drilling, DTH excavation (DTH mono-hammer and cluster 
drill), and rock hammering activities conducted as part of P-381 (Table 
14). Hydrophones will be placed at locations 10 m (33 ft) from the 
noise source and, where the potential for Level A harassment exists, at 
a second representative monitoring location at an intermediate distance 
between the cetacean and phocid shutdown zones. For the 10 percent of 
rotary drilling, DTH excavation (DTH mono-hammer and cluster drill), 
and rock hammering events acoustically measured, 100 percent of the 
data will be analyzed.
    At a minimum, the methodology includes:
    [ssquf] For underwater recordings, a stationary hydrophone system 
with the ability to measure SPLs will be placed in accordance with NMFS 
most recent guidance for the collection of source levels,
    [ssquf] Hydroacoustic monitoring will be conducted for 10 percent 
of each different type of activity not previously monitored as part of 
P-310 (Table 14). Monitoring will occur from the same locations 
approved by NMFS for P-310 construction activities. The resulting data 
set will be analyzed to examine and confirm sound pressure levels and 
rates of transmission loss for each separate in-water construction 
activity. With NMFS concurrence, these metrics will be used to 
recalculate the limits of shutdown and Level B harassment zones, and to 
make corresponding adjustments in marine mammal monitoring of these 
zones for use in the forthcoming rulemaking/LOA application. 
Hydrophones will be placed in the same manner as for P-310 construction 
activities. Locations of hydroacoustic recordings will be collected via 
GPS. A depth sounder and/or weighted tape measure will be used to 
determine the depth of the water. The hydrophone will be attached to a-
weighted nylon cord to maintain a constant depth and distance from the 
pile/drill/hammer location. The nylon cord or chain will be attached to 
a float or tied to a static line,
    [ssquf] Each hydrophone (underwater) will be calibrated at the 
start of each action and will be checked frequently to the applicable 
standards of the hydrophone manufacturer,
    [ssquf] For each monitored location, a single hydrophone will be 
suspended midway in the water column in order to evaluate site-specific 
attenuation and propagation characteristics that may be present 
throughout the water column,
    [ssquf] Environmental data will be collected, including but not 
limited to, the following: Wind speed and direction, air temperature, 
humidity, surface water temperature, water depth, wave height, weather 
conditions, and other factors that could contribute to influencing the 
airborne and underwater sound levels (e.g., aircraft, boats, etc.),
    [ssquf] The chief inspector will supply the acoustics specialist 
with the substrate composition, hammer/drill model and size, hammer/
drill energy settings, depth of drilling, and boring rates and any 
changes to those settings during the monitoring;
    [ssquf] For acoustically monitored construction activities, data 
from the continuous monitoring locations will be post-processed to 
obtain the following sound measures:
    [cir] Maximum peak pressure level recorded for all activities, 
expressed in dB re 1 [mu]Pa. This maximum value will originate from the 
phase of drilling/hammering during which drill/hammer energy was also 
at maximum (referred to as Level 4),
    [cir] From all activities occurring during the Level 4 phase these 
additional measures will be made, as appropriate:
    [ssquf] Mean, median, minimum, and maximum RMS pressure level in 
(dB re 1 [mu]Pa),
    [ssquf] Mean duration of a pile strike (based on the 90 percent 
energy criterion),
    [ssquf] Number of hammer strikes, and;
    [ssquf] Mean, median, minimum, and maximum single strike SEL (dB re 
[mu]Pa\2\ sec).
    [cir] Cumulative SEL as defined by the mean single strike SEL + 
10*log (number of hammer strikes) (dB re [mu]Pa\2\ sec),
    [cir] Median integration time used to calculate SPL RMS,
    [cir] A frequency spectrum (pressure spectral density) (dB re 
[mu]Pa\2\ per Hz) based on the average of up to eight successive 
strikes with similar sound. Spectral resolution will be 1 Hz, and the 
spectrum will cover nominal range from 7 Hz to 20 kHz, and;
    [cir] Finally, the cumulative SEL will be computed from all the 
strikes associated with each pile occurring during all phases, i.e., 
soft start, Level 1 to Level 4. This measure is defined as the sum of 
all single strike SEL values. The sum is taken of the antilog, with 
log<INF>10</INF> taken of result to express (dB re [mu]Pa\2\ sec).

                                   Table 14--Hydroacoustic Monitoring Summary
----------------------------------------------------------------------------------------------------------------
                 Size                             Count                     Activity           Number monitored
----------------------------------------------------------------------------------------------------------------
102-inch..............................  94.......................  Rotary Drill.............                   9
78-inch...............................  94.......................  DTH Cluster Drill........                   9
42-inch...............................  445......................  DTH Mono-hammer..........                  10

[[Page 19900]]

 
9-inch................................  154......................  DTH Mono-hammer..........                  10
4 to 6-inch...........................  2,701....................  DTH Mono-hammer..........                  10
NA....................................  252 days.................  Rock Hammering...........                  10
----------------------------------------------------------------------------------------------------------------

Marine Mammal Monitoring Reporting

    The Navy will submit a draft report to NMFS within 90 calendar days 
of the completion of monitoring or 60 calendar days prior to the 
requested issuance of any subsequent IHA for construction activity at 
the same location, whichever comes first. The report will detail the 
monitoring protocol and summarize the data recorded during monitoring. 
The final report must be prepared and submitted within 30 days 
following resolution of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 days of receipt of the draft 
report, the report will be considered final. If comments are received, 
a final report addressing NMFS comments must be submitted within 30 
days after receipt of comments. All draft and final marine mammal 
monitoring reports must be submitted to 
<a href="/cdn-cgi/l/email-protection#4e1e1c60071a1e60032120273a213c2720291c2b3e213c3a3d0e20212f2f60292138"><span class="__cf_email__" data-cfemail="f1a1a3dfb8a5a1dfbc9e9f98859e83989f96a394819e838582b19f9e9090df969e87">[email protected]</span></a> and <a href="/cdn-cgi/l/email-protection#6f263b3f412a08080a1d2f01000e0e41080019"><span class="__cf_email__" data-cfemail="1b524f4b355e7c7c7e695b75747a7a357c746d">[email protected]</span></a>. The report 
must contain the following informational elements, at minimum, (and be 
included in the Marine Mammal Monitoring Plan), including:
    [ssquf] Dates and times (begin and end) of all marine mammal 
monitoring;
    [ssquf] Construction activities occurring during each daily 
observation period, including:
    [cir] How many and what type of piles were driven and by what 
method (e.g., impact or vibratory); and
    [cir] Total duration of driving time for each pile (vibratory 
driving) and number of strikes for each pile (impact driving);
    [ssquf] PSO locations during marine mammal monitoring;
    [ssquf] 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;
    [ssquf] Upon observation of a marine mammal, the following 
information:
    [cir] PSO who sighted the animal and PSO location and activity at 
time of sighting;
    [cir] Time of sighting;
    [cir] Identification of the animal (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;
    [cir] Distance and bearing of each marine mammal observed to the 
pile being driven for each sighting (if pile driving was occurring at 
time of sighting);
    [cir] Estimated number of animals (minimum/maximum/best);
    [cir] Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.;
    [cir] Animal's closest point of approach and estimated time spent 
within the harassment zone; and
    [cir] Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses to the activity (e.g., no response 
or changes in behavioral state such as ceasing feeding, changing 
direction, flushing, or breaching);
    [ssquf] 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, if any; and
    [ssquf] All PSO datasheets and/or raw sightings data.

Reporting of Hydroacoustic Monitoring

    The Navy will also submit a draft hydroacoustic monitoring report 
to NMFS within 60 workdays of the completion of required monitoring at 
the end of the project. The report will detail the hydroacoustic 
monitoring protocol and summarize the data recorded during monitoring. 
The final report must be prepared and submitted within 30 days 
following resolution of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 days of receipt of the draft 
report, the report shall be considered final. If comments are received, 
a final report addressing NMFS comments must be submitted within 30 
days after receipt of comments. All draft and final hydroacoustic 
monitoring reports must be submitted to 
<a href="/cdn-cgi/l/email-protection#0555572b4c51552b486a6b6c716a776c6b625760756a777176456b6a64642b626a73"><span class="__cf_email__" data-cfemail="3464661a7d60641a795b5a5d405b465d5a536651445b464047745a5b55551a535b42">[email protected]</span></a> and <a href="/cdn-cgi/l/email-protection#175e4347395270707265577978767639707861"><span class="__cf_email__" data-cfemail="e7aeb3b7c9a280808295a789888686c9808891">[email protected]</span></a>. The 
hydroacoustic monitoring report will contain the informational elements 
described in the Hydroacoustic Monitoring Plan and, at minimum, will 
include:
    [ssquf] Hydrophone equipment and methods: Recording device, 
sampling rate, distance (m) from the pile where recordings were made; 
depth of water and recording device(s);
    [ssquf] Type and size of pile being driven, substrate type, method 
of driving during recordings (e.g., hammer model and energy), and total 
pile driving duration;
    [ssquf] Whether a sound attenuation device is used and, if so, a 
detailed description of the device used and the duration of its use per 
pile;
    [ssquf] For impact pile driving and/or DTH excavation (DTH mono-
hammer and cluster drill) (per pile): Number of strikes and strike 
rate; depth of substrate to penetrate; pulse duration and mean, median, 
and maximum sound levels (dB re: 1 [micro]Pa): Root mean square sound 
pressure level (SPLrms); cumulative sound exposure level (SELcum), peak 
sound pressure level (SPLpeak), and single-strike sound exposure level 
(SELs-s);
    [ssquf] For vibratory driving/removal and/or DTH excavation (DTH 
mono-hammer and cluster drill) (per pile): Duration of driving per 
pile; mean, median, and maximum sound levels (dB re: 1 [micro]Pa): Root 
mean square sound pressure level (SPLrms), cumulative sound exposure 
level (SELcum) (and timeframe over which the sound is averaged); and
    [ssquf] One-third octave band spectrum and power spectral density 
plot.
    [ssquf] General Daily Site Conditions
    [cir] Date and time of activities,
    [cir] Water conditions (e.g., sea state, tidal state); and
    [cir] Weather conditions (e.g., percent cover, visibility).

Reporting of Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Navy will report the 
incident to NMFS Office of Protected Resources (OPR) 
(<a href="/cdn-cgi/l/email-protection#4414166a0d10146a092b2a2d302b362d2a231621342b363037042a2b25256a232b32"><span class="__cf_email__" data-cfemail="8ededca0c7dadea0c3e1e0e7fae1fce7e0e9dcebfee1fcfafdcee0e1efefa0e9e1f8">[email protected]</span></a>), NMFS (301-427-8401) and to the 
Greater Atlantic Region New England/Mid-Atlantic Stranding Coordinator 
(866-755-6622) as soon as feasible. If the death or injury was clearly 
caused by the specified activity, the Navy must

[[Page 19901]]

immediately cease the specified 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 rule. The Navy will not resume their activities until notified 
by NMFS. The report must include the following information:
    [ssquf] Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    [ssquf] Species identification (if known) or description of the 
animal(s) involved;
    [ssquf] Condition of the animal(s) (including carcass condition if 
the animal is dead);
    [ssquf] Observed behaviors of the animal(s), if alive;
    [ssquf] If available, photographs or video footage of the 
animal(s); and
    [ssquf] 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 responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), 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 environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, this introductory discussion of our analyses 
applies to all of 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 in anticipated 
individual responses to activities, impacts of expected take on the 
population due to differences in population status, or impacts on 
habitat, they are described independently in the analysis below.
    Construction activities associated with the project, as outlined 
previously, have the potential to disturb or displace marine mammals. 
Specifically, the specified activities may result in take, in the form 
of Level A and Level B harassment from underwater sounds generated by 
pile driving activities, rotary drilling, rock hammering, and DTH. 
Potential takes could occur if marine mammals are present in zones 
ensonified above the thresholds for Level A and Level B harassment, 
identified above, while activities are underway.
    No serious injury or mortality would be expected even in the 
absence of the proposed mitigation measures. A bubble curtain will be 
installed across any openings at the entrance of super flood basin to 
attenuate sound for the sound sources that encompass the entire ROI 
include during DTH excavation (DTH mono-hammer and cluster drill), rock 
hammering, and impact pile driving of sheet piles. During all impact 
driving, implementation of soft start procedures and monitoring of 
established shutdown zones will be required, significantly reducing the 
possibility of injury. Given sufficient notice through use of soft 
start (for impact driving), marine mammals are expected to move away 
from an irritating sound source prior to it becoming potentially 
injurious. In addition, PSOs will be stationed within the action area 
whenever pile driving, rotary drilling, rock hammering and DTH 
activities are underway. The Navy shall employ the use of three PSOs to 
ensure all monitoring and shutdown zones are properly observed. For 
hooded and harp seals which are a rare species in within the project 
area, we do not anticipate any take by Level A harassment.
    The Navy's planned activities and associated impacts will occur 
within a limited area. Most of the work will occur behind the existing 
super flood basin walls that would act as a barrier to sound and would 
contain underwater noise to within a small portion of the Piscataqua 
River. Exposures to elevated sound levels produced during pile driving 
activities may cause behavioral disturbance of some individuals, but 
they are expected to be mild and temporary and further minimized by the 
use of a bubble curtain and soft starts. As described previously, the 
mitigation and monitoring measures are expected to further reduce the 
likelihood of injury as well as reduce behavioral disturbances.
    Effects on individuals that are taken by Level B harassment, as 
enumerated in the Estimated Take section, on the basis of reports in 
the literature as well as monitoring from other similar activities, 
will likely be limited to reactions such as increased swimming speeds, 
increased surfacing time, or decreased foraging (if such activity were 
occurring) (e.g., Thorson and Reyff 2006). Most likely, individual 
animals will simply move away from the sound source and be temporarily 
displaced from the area, although even this reaction has been observed 
primarily only in association with impact pile driving. The activities 
analyzed here are similar to numerous other construction activities 
conducted along both Atlantic and Pacific coasts, which have taken 
place with no known long-term adverse consequences from behavioral 
harassment. These reactions and behavioral changes are expected to 
subside quickly when the exposures cease. Level B harassment will be 
minimized through use of mitigation measures described herein. 
including the soft starts and the use of the bubble curtain, which was 
not quantitatively factored into the take estimates.
    Regarding Level A harassment particularly for harbor seals and gray 
seals, monitoring and shutdown protocols, and a bubble curtain 
implemented during DTH excavation (DTH mono-hammer and cluster drill), 
hydraulic rock hammering, and impact pile driving of sheet piles would 
minimize potential for take by Level A harassment. For pinnipeds, the 
calculated Level A harassment likely overestimates PTS exposure 
because: (1) Seals are unlikely to remain in the Level A harassment 
zone underwater long enough to accumulate sufficient exposure to noise 
resulting in PTS, and (2) the estimate assumes that new seals are in 
the Level A harassment zone every day during pile driving. Further as 
discussed above, take by Level A harassment would be minimized due to 
implementation of monitoring, shutdown procedures and a bubble curtain. 
Nonetheless, we have considered the potential impacts of these PTS 
takes occurring in this analysis. The degree of PTS that may incur from 
the Navy's activities are not

[[Page 19902]]

expected to impact marine mammals such that their reproduction or 
survival could be affected. Similarly, data do not suggest that a 
single instance in which an animal accrues PTS (or TTS) and is subject 
to behavioral disturbance would result in impacts to reproduction or 
survival. If PTS were to occur, it would be at a lower level likely to 
accrue to a relatively small portion of the population by being a 
stationary activity in one particular location.
    The project is also not expected to have significant adverse 
effects on any marine mammal habitat. The project activities will not 
modify existing marine mammal habitat since the project will occur 
within the same footprint as existing marine infrastructure. Impacts to 
the immediate substrate are anticipated, but these would be limited to 
minor, temporary suspension of sediments, which could impact water 
quality and visibility for a short amount of time but which would not 
be expected to have any effects on individual marine mammals. The 
nearshore and intertidal habitat where the project will occur is an 
area of consistent vessel traffic from Navy and non-Navy vessels, and 
some local individuals would likely be somewhat habituated to the level 
of activity in the area, further reducing the likelihood of more severe 
impacts. The closest pinniped haulout used by harbor and gray seals is 
2,414 m (1.5 mi) away on the opposite side of the island and not within 
the ensonified area. There are no other biologically important areas 
for marine mammals near the project area.
    In addition, impacts to marine mammal prey species are expected to 
be minor and temporary. Overall, the area impacted by the project is 
very small compared to the available surrounding habitat. The most 
likely impact to prey will be temporary behavioral avoidance of the 
immediate area. During construction activities, it is expected that 
some fish and marine mammals would temporarily leave the area of 
disturbance, thus impacting marine mammals' foraging opportunities in a 
limited portion of the foraging range. But, because of the relatively 
small area of the habitat that may be affected, the impacts to marine 
mammal habitat are not expected to cause significant or long-term 
negative consequences.
    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:
    [ssquf] No mortality is anticipated or proposed for authorization;
    [ssquf] No Level A harassment is anticipated or proposed for 
authorization for hooded seals and harp seals;
    [ssquf] Level A harassment proposed for authorization for harbor 
and gray seals will be minimized with a bubble curtain and shutdown 
zones and is expected to be of a lower degree that would not impact the 
fitness of any animals;
    [ssquf] Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior;
    [ssquf] The required mitigation measures (i.e., bubble curtain, 
shutdown zones) are expected to be effective in reducing the effects of 
the specified activity;
    [ssquf] Minimal impacts to marine mammal habitat/prey are expected;
    [ssquf] The action area is located within an active marine shipyard 
area,
    [ssquf] There is one pinniped haulouts in the vicinity of the 
project area, but it is on the opposite side of Seavey Island and not 
within the ensonified area; and
    [ssquf] There are no known biologically important areas in the 
vicinity of the project. 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 
monitoring and mitigation measures, NMFS finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers, 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.
    Take of five of the marine mammal stocks proposed for authorization 
will comprise at most approximately 3 percent or less of the stock 
abundance (Table 12). The number of animals proposed for authorization 
to be taken from these stocks would be considered small relative to the 
relevant stock's abundances even if each estimated take occurred to a 
new individual, which is an unlikely scenario. Based on the analysis 
contained herein of the planned activity (including the 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 would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

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 review our proposed action (i.e., the issuance of an IHA) 
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 NOAA Administrative Order 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 would preclude this 
categorical exclusion. Accordingly, NMFS has determined that the 
issuance of the IHA qualifies to be categorically excluded from further 
NEPA review.

Endangered Species Act (ESA)

    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Authorization

    NMFS has issued an IHA to the Navy for the taking of marine mammals 
incidental to modification and expansion of the Portsmouth Naval 
Shipyard Dry Dock 1 in Kittery, Maine, effective for one year from the 
date of issuance, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated


[[Page 19903]]


    Dated: April 1, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2022-07257 Filed 4-5-22; 8:45 am]
BILLING CODE 3510-22-P


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>