[Federal Register Volume 86, Number 224 (Wednesday, November 24, 2021)]
[Notices]
[Pages 67024-67035]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-25627]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB598]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Parallel Thimble Shoal Tunnel 
Project in Virginia Beach, Virginia

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the Chesapeake Tunnel Joint Venture (CTJV) to incidentally harass, by 
Level A and Level B harassment only, marine mammals during construction 
activities associated with the Parallel Thimble Shoal Tunnel Project 
(PTST) in Virginia Beach, Virginia.

DATES: This authorization is effective for one year from the date of 
issuance.

FOR FURTHER INFORMATION CONTACT: Dwayne Meadows, Ph.D., 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

[[Page 67025]]

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 the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth.
    The definitions of all applicable MMPA statutory terms cited above 
are included in the relevant sections below.

Summary of Request

    On September 21, 2021, NMFS received an application from CTJV 
requesting an IHA to take small numbers of five species (harbor seal 
(Phoca vitulina), gray seal (Halichoerus grypus), bottlenose dolphin 
(Tursiops truncatus), harbor porpoise (Phocoena phocoena) and humpback 
whale (Megaptera novaeangliae)) of marine mammals incidental to pile 
driving and removal associated with the PTST Project. The application 
was deemed adequate and complete on September 30, 2021. CTJV's request 
is for take of a small number of these species by Level A or Level B 
harassment. Neither CTJV nor NMFS expects serious injury or mortality 
to result from this activity and, therefore, an IHA is appropriate. 
NMFS previously issued IHAs to CTJV for similar work (83 FR 36522; July 
30, 2018; 85 FR 16061; March 20, 2020; and 86 FR 14606; March 17, 
2021). However, due to design and schedule changes only a small portion 
of that work was conducted under those issued IHAs. This proposed IHA 
covers one year of a five year project.

Description of Specified Activity

Overview

    The purpose of the project is to build an additional two-lane 
vehicle tunnel under the navigation channel as part of the Chesapeake 
Bay Bridge and Tunnel (CBBT). The PTST project will address existing 
constraints to regional mobility based on current traffic volume, 
improve safety, improve the ability to conduct necessary maintenance 
with minimal impact to traffic flow, and ensure reliable hurricane 
evacuation routes. In-water pile driving is needed to create vessel 
moorings, temporary work trestles and Support of Excavation walls on 
islands at either end of the tunnel. The work in this application 
involves the installation of 722 36-inch and 42 42-inch steel piles. 
The project will take no more than 252 days of in-water pile work. A 
detailed description of the planned project is provided in the Federal 
Register notice for the proposed IHA (86 FR 56902; October 13, 2021). 
Since that time, no changes have been made to the planned activities. 
Therefore, a detailed description is not provided here. Please refer to 
that Federal Register notice for the description of the specific 
activity.

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to CTJV was published 
in the Federal Register on October 13, 2021 (86 FR 56902). That notice 
described, in detail, CTJV'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 one 
public comment from a member of the public who was completely 
supportive of the project with no substantive comments.

Changes From the Proposed IHA

    Since publication of the proposed IHA, NMFS has published the draft 
2021 Stock Assessment Report (SAR, https://media.fisheries.noaa.gov/2021-10/Draft%202021%20NE% 26SE%20SARs.pdf). The SAR provides updated 
information for harbor porpoise, harbor seal, and gray seal that does 
not affect our analysis or findings (see Table 1).

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's 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's website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species with expected potential for occurrence in 
the project area in Chesapeake Bay and summarizes information related 
to the population or stock, including regulatory status under the MMPA 
and Endangered Species Act (ESA) and potential biological removal 
(PBR), where known. For taxonomy, we follow Committee on Taxonomy 
(2020). 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's 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. As 
noted above, the recent draft SAR provides updated information for 
three species. Harbor porpoise mortality and serious injury declined 
slightly. Harbor seal abundance declined by about 15 percent and gray 
seal abundance increased slightly. Other parameters also had minor 
changes, see Table 1 for the revised information.
    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's 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's U.S. Atlantic SARs (e.g., Hayes et al., 2021; draft 2021 SAR).

[[Page 67026]]



                    Table 1--Species That Spatially Co-Occur With the Activity to the Degree That Take is Reasonably Likely To Occur
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                                                                                         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 Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Gulf of Maine..........  -,-; N              1,393 (0; 1,375, 2016)         22         58
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin..............  Tursiops truncatus.....  WNA Coastal, Northern    -,-; Y              6,639 (0.41; 4,759;            48  12.2-21.5
                                                                Migratory.                                   2011).
                                                               WNA Coastal, Southern    -,-; Y              3,751 (0.06; 2,353;            23        0-8
                                                                Migratory.                                   2011).
                                                               Northern North Carolina  -,-; Y              823 (0.06; 782; 2017).        7.8     7.2-30
                                                                Estuarine System.
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of     -, -; N             95,543 (0.31; 74,034;         851        164
                                                                Fundy.                                       2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  WNA....................  -; N                61,336 (0.08; 57,637,        1729        339
                                                                                                             2018).
    Gray seal \4\...................  Halichoerus grypus.....  WNA....................  -; N                27,300 (0.22, 22,785,       1,359      4,453
                                                                                                             2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual Mortality/Serious Injury (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\ The NMFS stock abundance estimate applies to U.S. population only, however the actual stock abundance is approximately 505,000. The PBR value is
  estimated for the U.S. population, while the M/SI estimate is provided for the entire gray seal stock (including animals in Canada).

    A detailed description of the of the species likely to be affected 
by 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 (86 56902; October 13, 
2021); 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 CTJV's construction activities 
have the potential to result in behavioral harassment of marine mammals 
in the vicinity of the survey area. The notice of proposed IHA (86 FR 
56902; October 13, 2021) included a discussion of the effects of 
anthropogenic noise on marine mammals and the potential effects of 
underwater noise from CTJV's construction on marine mammals and their 
habitat. That information and analysis is incorporated by reference 
into this final IHA determination and is not repeated here; please 
refer to the notice of proposed IHA (86 FR 56902; October 13, 2021).

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized 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, as use 
of the acoustic sources (i.e., vibratory or impact pile driving and 
down-the-hole (DTH)) have the potential to result in disruption of 
behavioral patterns for individual marine mammals. There is also some 
potential for auditory injury (Level A harassment) to result for 
pinnipeds and harbor porpoise because predicted auditory injury zones 
are larger. The mitigation and monitoring measures are expected to 
minimize the severity of the taking to the extent practicable.
    As described previously, no mortality is anticipated or authorized 
for this activity. Below we describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which 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) and the

[[Page 67027]]

number of days of activities. We note that while these basic 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). Due to the lack of marine mammal 
density data available for this location, NMFS relied on local 
occurrence data and group size to estimate take for some species. 
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 for Non-Explosive Sources
    Though significantly driven by received level, the onset of 
behavioral disturbance from anthropogenic noise exposure is also 
informed to varying degrees by other factors related to the source 
(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) and above 160 dB re 1 [mu]Pa (rms) for non-explosive impulsive 
(e.g., impact pile driving) or intermittent (e.g., scientific sonar) 
sources.
    CTJV's proposed activity includes the use of continuous (vibratory 
hammer and DTH) and impulsive (impact pile-driving) sources, and 
therefore the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are 
applicable. However, CTJV recorded ambient sounds at the project site 
for over two weeks in 2019 (https://media.fisheries.noaa.gov/dam-migration/ctjvthimbleshoals_final_ssv_report_opr1_3-23.pdf) and 
established that median ambient sounds levels were 122.78 dB. We have 
therefore agreed to use this value as the threshold for the continuous 
sources.
Level A Harassment for Non-Explosive Sources
    NMFS' Technical Guidance for Assessing the Effects of Anthropogenic 
Sound on Marine Mammal Hearing (Version 2.0) (Technical Guidance, 2018) 
identifies dual criteria to assess auditory injury (Level A harassment) 
to five different marine mammal groups (based on hearing sensitivity) 
as a result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). CTJV's activity includes the use of 
impulsive (impact pile-driving and DTH) and non-impulsive (vibratory 
hammer and DTH) sources.
    These thresholds are provided in Table 2. The references, analysis, 
and methodology used in the development of the thresholds are described 
in NMFS 2018 Technical Guidance, which may be accessed at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact and vibratory pile 
driving, and DTH).
    In order to calculate distances to the Level A harassment and Level 
B harassment sound thresholds for the methods and piles being used in 
this project, NMFS used acoustic monitoring data from other locations 
to develop source levels for the various pile types, sizes and methods 
(Table 3). Based on monitoring the sound source levels for some piles 
with versus without a bubble curtain in prior years of this project it 
was determined that the bubble curtain system used for this project 
provided a 6 db reduction in near field sound levels (https://media.fisheries.noaa.gov/dam-migration/ctjvthimbleshoals_final_ssv_report_opr1_3-23.pdf) and we have agreed to 
apply this reduction in source levels for this proposed work.

[[Page 67028]]



                                      Table 3--Project Sound Source Levels
----------------------------------------------------------------------------------------------------------------
                                      Estimated noise levels
               Method                          (dB)                                 Source
----------------------------------------------------------------------------------------------------------------
DTH--impulsive......................  164 SELss.............  Reyff & Heyvaert (2019)
DTH--non-impulsive..................  166 dB RMS............  Denes et al. (2016)
Impact..............................  204 Pk, 177 SEL *.....  Caltrans (2015) Table I.2.1
Vibratory...........................  174 Pk, 164 RMS *.....  Caltrans (2015) Table I.2.2
----------------------------------------------------------------------------------------------------------------
Note: SEL = single strike sound exposure level; RMS = root mean square.
* Source levels reduced by 6 dB to account for use of bubble curtain.

Level B Harassment Zones

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

TL = B * Log10 (R1/R2), where
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for CTJV's proposed activity in the absence of specific 
modelling.
    CTJV determined underwater noise would fall below the behavioral 
effects threshold of 160 dB RMS for impact driving at 136 m and the 
122.78 dB rms threshold for vibratory driving at 5,598 m (Table 4). 
Distances to the 122.78 threshold for the various combinations of 
simultaneous DTH, vibratory pile driving, and/or impact pile driving 
range from 7,609 to 14,061 m (Table 4). It should be noted that based 
on the bathymetry and geography of the project area, sound will not 
reach the full distance of the harassment isopleths in all directions 
(see Application Appendix A).

Level A Harassment Zones

    When the NMFS Technical Guidance (2016) was published, 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, we 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 
overestimate of take by Level A harassment. 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 
pile driving or removal and DTH using any of the methods discussed 
above, NMFS User Spreadsheet 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. We used the User Spreadsheet to 
determine the Level A harassment isopleths. Inputs used in the User 
Spreadsheet or models are 12 minutes per pile for vibratory hammer, 
1000 strikes per pile for impact hammer, and 36,000 strikes per pile 
for DTH. All scenarios use a Transmission Loss Coefficient of 15. 
Resulting isopleths are reported in Table 4 for each of the 
construction methods and scenarios.

                         Table 4--Level A and Level B Isopleths (Meters) for Each Method
----------------------------------------------------------------------------------------------------------------
                                             Low-        Mid-        High-
        Method and piles per day           frequency   frequency   frequency    Phocids    Otariids     Level B
                                           cetaceans   cetaceans   cetaceans
----------------------------------------------------------------------------------------------------------------
DTH (3 per day).........................       1,226          44       1,460         656          48       7,609
DTH (6 per day).........................       1,946          70       2,318       1,042          76      12,060
Impact (4 per day)......................       1,002          36       1,194         537          39         136
Impact (6 per day)......................       1,313          47       1,564         703          52         136
Vibratory...............................           9           1          14           6           1       5,598
                                         ------------------------------------------------------------
Impact + DTH............................                Use zones for each source alone                    7,609
DTH + Vibratory.........................                         Use DTH zones                            10,344
Impact + Vibratory......................                       Use Impact zones                            5,598
Impact + DTH + DTH......................                Use zones for each source alone                   12,060
DTH + DTH+ Vibratory....................                         Use DTH zones                            14,061
DTH + Vibratory + Impact................                         Use DTH zones                            10,344
Impact + Impact + DTH...................                Use zones for each source alone                    7,609
----------------------------------------------------------------------------------------------------------------

    Because CTJV will use multiple simultaneous methods we need to 
account for the effect of this on sound levels. When two non-impulsive 
continuous noise sources, such as vibratory hammers or DTH, have 
overlapping sound fields, there is potential for higher sound levels 
than for non-overlapping sources. In these cases, the sources may be 
considered additive and combined using the rules in Table 5. For 
addition of two simultaneous non-impulsive continuous sources, the 
difference between the two sound source levels (SSLs) is calculated,

[[Page 67029]]

and if that difference is between 0 and 1 dB, 3 dB are added to the 
higher SSL; if difference is between 2 or 3 dB, 2 dB are added to the 
highest SSL; if the difference is between 4 to 9 dB, 1 dB is added to 
the highest SSL; and with differences of 10 or more dB, there is no 
addition.
    For simultaneous usage of three or more continuous sound sources, 
the three overlapping sources with the highest SSLs are identified. Of 
the three highest SSLs, 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 SSLs 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 
SSLs (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 SSL 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 2018b; WSDOT 2018).
    Simultaneous use of two or more impact hammers or DTH does not 
require this sort of source level additions on its own. For impact 
hammering or DTH, it is unlikely that the two (or more) hammers would 
strike at the same exact instant, and therefore, the sound source 
levels will not be adjusted regardless of the distance between the 
hammers.

                  Table 5--Rules for Combining Sound Levels Generated During Pile Installation
----------------------------------------------------------------------------------------------------------------
             Hammer types                 Difference in SSL          Level A zones            Level B zones
----------------------------------------------------------------------------------------------------------------
Non-impulsive, Impulsive.............  Any....................  Use impulsive zones....  Use largest zone.
Impulsive, Impulsive.................  Any....................  Use zones for each pile  Use zone for each pile
                                                                 size and number of       size.
                                                                 strikes.
Non-impulsive, Non-impulsive.........  0 or 1 dB..............  Add 3 dB to the higher   Add 3 dB to the higher
                                                                 source level.            source level.
                                       2 or 3 dB..............  Add 2 dB to the higher   Add 2 dB to the higher
                                                                 source level.            source level.
                                       4 to 9 dB..............  Add 1 dB to the higher   Add 1 dB to the higher
                                                                 source level.            source level.
                                       10 dB or more..........  Add 0 dB to the higher   Add 0 dB to the higher
                                                                 source level.            source level.
----------------------------------------------------------------------------------------------------------------

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. Here we describe how the information provided above is 
brought together to produce a quantitative take estimate. A summary of 
proposed take is in Table 6.
Humpback Whale
    Density data for this species in the project vicinity do not exist. 
Populations in the mid-Atlantic have been estimated for humpback whales 
off the coast of New Jersey with a density of 0.000130/km\2\ (Whitt et 
al., 2015). In the Project area, a similar density may be expected. 
Aschettino et al. (2018) observed and tracked 12 individual humpback 
whales west of the CBBT. Based on these data, and the known movement of 
humpback whales from November through April at the mouth of the 
Chesapeake Bay, and as used in the prior IHAs, CTJV is requesting and 
we are proposing take of a single humpback group every two months for 
the duration of in-water pile driving activities. There are 12 months 
of in-water construction anticipated during the proposed IHA. Using an 
average group size of two animals, pile driving activities over a 12-
month period would result in 12 takes of humpback whale by Level B 
harassment.
    No takes by Level A harassment are expected or authorized because 
we expect CTJV will effectively shutdown for low-frequency whales 
including humpbacks at the full extent of the Level A harassment zones.
Bottlenose Dolphin
    In the previous IHA for this project we used seasonal density 
values documented by Engelhaupt et al. (2016). The Level B harassment 
area for each pile and driving type was multiplied by the appropriate 
seasonal density and the anticipated number of days of a specific 
activity per month number to derive a total number of takes for each 
construction project component. We use the same approach here. The 
number of calculated takes for the project is 86,656 (Table 7). There 
is insufficient information on relative abundance to apportion the 
takes precisely to the three stocks present in the area. We use the 
same approach used in the prior IHAs as well as in the nearby Hampton 
Roads Bridge and Tunnel project (86 FR 17458; April 2, 2021). Given 
that most of the Northern North Caroline Estuarine Stock (NNCES) stock 
are found in the Pamlico Sound estuarine system, NMFS will assume that 
no more than 250 of the authorized takes will be from this stock. Since 
members of the northern migratory coastal and southern migratory 
coastal stocks are thought to occur in or near the Bay in greater 
numbers, we will conservatively assume that no more than half of the 
remaining animals will accrue to either of these stocks. Additionally, 
a subset of these takes would likely be comprised of Chesapeake Bay 
resident dolphins, although the size of that population is unknown.
    No takes by Level A harassment are authorized because we expect 
CTJV will effectively shutdown for bottlenose dolphins at the full 
extent of the Level A harassment zones.
Harbor Porpoise
    Density data for this species in the project vicinity do not exist. 
Given that harbor porpoises are uncommon in the project area, this 
exposure analysis (as we did for the prior IHAs) assumes that there is 
a porpoise sighting once during every two months of operations which 
would equate to six sightings during the year. Assuming an average 
group size of two (Hansen et al., 2018; Elliser et al., 2018) results 
in a total of 12 estimated takes of porpoises over a year.
    Harbor porpoises are members of the high-frequency hearing group 
which have Level A harassment isopleths as large as 2,318 m during DTH 
installation of 6 piles per day. In the previous IHA the shutdown zone 
was set at 100 m since harbor porpoises are cryptic, were thought to be 
somewhat common in the project area and are known to approach the 
shoreline. There was concern there would be excessive shutdowns that 
would extend the project and days of exposure of marine mammals to 
sound if the zones were larger. However, monitoring data to date 
suggests we can increase the shutdown zone to 200 m and still avoid an 
impracticable number

[[Page 67030]]

of shutdowns. Therefore, we are implementing a 200 m shutdown zone as a 
mitigation measure. Given the relatively large Level A harassment zones 
during impact driving and DTH, NMFS assumed in the previous IHAs that 
40 percent of estimated porpoise takes would be by Level A harassment. 
The monitoring data on harbor porpoise take to date do not contradict 
this expectation. We therefore continue to assume this percentage, 
resulting in five takes of porpoises by Level A harassment and seven 
takes by Level B harassment.
Harbor Seal
    With new data on harbor seals since the initial IHAs, we are 
altering our estimation method for this species. The new method also 
aligns with what we have used in other recent nearby projects. The 
number of harbor seals expected to be present in the PTST project area 
was estimated using survey data for in-water and hauled out seals 
collected by the U.S. Navy at the portal islands from November 2014 
through 2019 (Rees et al., 2016; Jones et al., 2020). The survey showed 
a daily average seal count of 13.6. We rounded this up to 14 seals per 
day We multiplied that number by 95 in-water work days on Portal Island 
1 and 111 work days on Portal Island 2 (the number of days of in-water 
activities when the seals are present, December to May) to estimate 
2,884 takes of harbor seals.
    The largest Level A harassment isopleth for phocid species is 1,042 
meters (m), which would occur during DTH of 6 large holes per day. In 
the previous IHA the shutdown zone was set at 15 m since seals are 
common in the project area and are known to approach the shoreline. 
There was concern there would be excessive shutdowns that would extend 
the project and days of exposure of marine mammals to sound if the 
zones were larger. However, monitoring data to date suggests we can 
increase the shutdown zone to 150 m and still avoid an impracticable 
number of shutdowns. Therefore, we are implementing a shutdown zone of 
150 m for harbor seals. As discussed above for harbor porpoises we 
assume that 40 percent of the exposed seals will occur within the Level 
A harassment zone and the remaining affected seals would result in 
Level B harassment takes. Therefore, NMFS is authorizing 1,154 takes by 
Level A harassment and 1,730 takes by Level B harassment.

Gray Seal

    The number of gray seals expected to be present at the PTST project 
area was estimated using survey data collected by the U.S. Navy at the 
portal islands from 2014 through 2018 (Rees et al., 2016; Jones et al., 
2018). One seal was observed in February of 2015 and one seal was 
recorded in February of 2016, while no seals were observed at any other 
time. So the February rate of seal per day was estimated at 1.6. We 
rounded this to 2 animals per day and multiplied by the number of 
expected work days in February (20) to arrive at an estimate of 40 
takes of gray seals per year.
    The largest Level A harassment isopleth for phocid species is 1,042 
m, which would occur during DTH of 6 large holes per day. In the 
previous IHA the shutdown zone was set at 15 m since seals are common 
in the project area and are known to approach the shoreline. There was 
concern there would be excessive shutdowns that would extend the 
project and days of exposure of marine mammals to sound if the zones 
were larger. However, monitoring data to date suggests we can increase 
the shutdown zone to 150 m and still avoid an impracticable number of 
shutdowns. Therefore, we are implementing a shutdown zone of 150 m for 
gray seals. As above we estimate 40 percent of these takes could be by 
Level A harassment, so we authorize 24 Level B harassment takes and 16 
Level A harassment takes for gray seals.

  Table 6--Authorized Amount of Taking, by Level A Harassment and Level B Harassment, by Species and Stock and
                                            Percent of Take by Stock
----------------------------------------------------------------------------------------------------------------
                                                                             Level A      Level B     Percent of
                Common name                             Stock               harassment   harassment     stock
----------------------------------------------------------------------------------------------------------------
Humpback whale............................  Gulf of Maine................            0           12          0.9
Harbor Porpoise...........................  Gulf of Maine/Bay of Fundy...            5            7         <0.1
Bottlenose dolphin........................  WNA Coastal, Northern                    0       43,203          651
                                             Migratory.
Bottlenose dolphin........................  WNA Coastal, Northern                    0       43,203          651
                                             Migratory.
Bottlenose dolphin........................  NNCES........................            0          250         30.4
Harbor seal...............................  Western North Atlantic.......        1,154        1,730          4.7
Gray seal.................................  Western North Atlantic.......           16           24         <0.1
----------------------------------------------------------------------------------------------------------------


                    Table 7--Data To Estimate Level B Harassment Take of Bottlenose Dolphins
----------------------------------------------------------------------------------------------------------------
                                                                                             Level B
             Months                         Nov.     Dec.-    March-     June-     Sept.-    area (km   Dolphin
                                                     Feb.       May      Aug.       Oct.       \2\)       take
----------------------------------------------------------------------------------------------------------------
Dolphin Density/km \2\.........   Island     3.88      0.63         1      3.55      3.88   .........  .........
Impact + DTH...................        1       17        40        16         4         0         136     16,507
Impact + DTH...................        2        0         3         7        50        38         147     46,766
DTH + Vibratory................        1        2         4         1         1         0         218      3,235
DTH + Vibratory................        2        0         0         1         2         2         250      3,966
Impact + Vibratory.............        1        2         4         1         1         0          80      1,188
Impact + Vibratory.............        2        0         0         1         2         2          79      1,176
DTH + DTH + Impact.............    1 & 2        0         4        13         1         0         323      6,161
DTH + DTH + Vibratory..........    1 & 2        0         1         5         0         0         402      2,264
DTH + Vibratory + Impact.......    1 & 2        0         2         5         1         0         255      2,181
Impact + Impact + DTH..........    1 & 2        0         5        13         1         0         163      3,212
----------------------------------------------------------------------------------------------------------------
Note: Take is calculated by multiplying the density for a given time by the Area of the Level B harassment zone
  and the number of days of work (found in the main cells of the table). See more detailed table with monthly
  totals in Table 16 of the application.


[[Page 67031]]

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, 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.
    The following mitigation measures are included in the IHA:
     Avoid direct physical interaction with marine mammals 
during construction activity. If a marine mammal comes within 10 m of 
such activity, operations must cease and vessels must reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions;
     Conduct training between construction supervisors and 
crews and the marine mammal monitoring team and relevant CTJV staff 
prior to the start of all pile driving and DTH activity and when new 
personnel join the work, so that responsibilities, communication 
procedures, monitoring protocols, and operational procedures are 
clearly understood;
     Pile driving activity must 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 
harassment zone;
     CTJV will establish and implement the shutdown zones 
indicated in Table 8. 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 typically vary based on the activity 
type and marine mammal hearing group;
     Employ Protected Species Observers (PSOs) and establish 
monitoring locations as described in the Marine Mammal Monitoring Plan 
and Section 5 of the IHA. The Holder must monitor the project area to 
the maximum extent possible based on the required number of PSOs, 
required monitoring locations, and environmental conditions. For all 
pile driving and removal at least one PSO must be used. The PSO will be 
stationed as close to the activity as possible;
     The placement of the PSOs during all pile driving and 
removal and DTH activities will ensure that the entire shutdown zone is 
visible during pile installation. Should environmental conditions 
deteriorate such that marine mammals within the entire shutdown zone 
will not be visible (e.g., fog, heavy rain), pile driving and removal 
must be delayed until the PSO is confident marine mammals within the 
shutdown zone could be detected;
     Monitoring must take place from 30 minutes prior to 
initiation of pile driving activity through 30 minutes post-completion 
of pile driving activity. Pre-start clearance monitoring must be 
conducted during periods of visibility sufficient for the lead PSO to 
determine the shutdown zones clear of marine mammals. Pile driving may 
commence following 30 minutes of observation when the determination is 
made;
     If pile driving is delayed or halted due to the presence 
of a marine mammal, the activity may not commence or resume until 
either the animal has voluntarily exited and been visually confirmed 
beyond the shutdown zone or 15 minutes have passed without re-detection 
of the animal;
     CTJV must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a 30-second waiting 
period, then two subsequent reduced-energy strike sets. A soft start 
must 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; and
     Use a bubble curtain during impact and vibratory pile 
driving and DTH in water depths greater than three m and ensure that it 
is operated as necessary to achieve optimal performance, and that no 
reduction in performance may be attributable to faulty deployment. At a 
minimum, CTJV must adhere to the following performance standards: The 
bubble curtain must distribute air bubbles around 100 percent of the 
piling circumference for the full depth of the water column. The lowest 
bubble ring must be in contact with the substrate for the full 
circumference of the ring, and the weights attached to the bottom ring 
shall ensure 100 percent substrate contact. No parts of the ring or 
other objects shall prevent full substrate contact. Airflow to the 
bubblers must be balanced around the circumference of the pile. For 
work with interlocking pipe piles for the berm construction a special 
three-sided bubble curtain will be used (see Application Appendix A).

                                Table 8--Shutdown Zones (meters) for Each Method
----------------------------------------------------------------------------------------------------------------
                                            Low-frequency     Mid-frequency    High-frequency
          Method and piles/day                cetaceans         cetaceans         cetaceans          Phocids
----------------------------------------------------------------------------------------------------------------
DTH (3/day).............................              1230                50               200               150
DTH (6/day).............................              1950                70               200               150
Impact (4/day)..........................              1010                40               200               150
Impact (6/day)..........................              1320                50               200               150

[[Page 67032]]

 
Vibratory (4/day).......................                20                10                20                10
                                         -----------------------------------------------------------------------
Impact + DTH............................  Use zones for each source alone
                                         -----------------------------------------------------------------------
DTH + Vibratory.........................              1230                50               200               150
Impact + Vibratory......................              1320                50               200               150
Impact + DTH + DTH......................              1320                50               200               150
DTH + DTH+ Vibratory....................              1950                70               200              1050
DTH + Vibratory + Impact................              1320                50               200               710
                                         -----------------------------------------------------------------------
Impact + Impact + DTH...................  Use zones for each source alone
----------------------------------------------------------------------------------------------------------------

    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.

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 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Monitoring must be conducted by qualified, NMFS-approved PSOs, in 
accordance with the following: PSOs must be independent (i.e., not 
construction personnel) and have no other assigned tasks during 
monitoring periods. At least one PSO must have prior experience 
performing the duties of a PSO during construction activity pursuant to 
a NMFS-issued incidental take authorization. Other PSOs may substitute 
other relevant experience, education (degree in biological science or 
related field), or training. PSOs must be approved by NMFS prior to 
beginning any activity subject to this IHA.
     PSOs must record all observations of marine mammals as 
described in the Section 5 of the IHA and the Marine Mammal Monitoring 
Plan, regardless of distance from the pile being driven. PSOs shall 
document any behavioral reactions in concert with distance from piles 
being driven or removed;
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary; and
     CTJV must establish the following monitoring locations. 
For all pile driving and DTH activities, a minimum of one PSO must be 
assigned to the active pile driving or DTH location to monitor the 
shutdown zones and as much of the Level A and Level B harassment zones 
as possible. For activities in Table 4 above with Level B harassment 
zones larger than 6000 m, an additional PSO must be stationed at Fort 
Story to monitor as much of the Level B harassment zone as possible.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities, or 60 days prior to a requested date of issuance of any 
future IHAs for projects at the same location, whichever comes first. 
The report will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:

[[Page 67033]]

     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including the number and type of piles driven or 
removed and by what method (i.e., impact or cutting) and the total 
equipment duration for cutting for each pile or total number of strikes 
for each pile (impact driving);
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information: Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting; Time of sighting; Identification of the 
animal(s) (e.g., genus/species, lowest possible taxonomic level, or 
unidentified), PSO confidence in identification, and the composition of 
the group if there is a mix of species; Distance and bearing of each 
marine mammal observed relative to the pile being driven for each 
sighting (if pile driving was occurring at time of sighting); Estimated 
number of animals (min/max/best estimate); Estimated number of animals 
by cohort (adults, juveniles, neonates, group composition, etc.); 
Animal's closest point of approach and estimated time spent within the 
harassment zone; Description of any marine mammal behavioral 
observations (e.g., observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g., no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
     Number of marine mammals detected within the harassment 
zones, by species; and
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder must 
immediately cease the specified activities and report the incident to 
the Office of Protected Resources (OPR) 
([email protected]), NMFS and to Greater Atlantic 
Regional Stranding Coordinator as soon as feasible. If the death or 
injury was clearly caused by the specified activity, CTJV must 
immediately cease the specified activities until NMFS is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHA. The IHA-holder must not resume their activities until 
notified by NMFS. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any 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's 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).
    Pile driving and removal and DTH activities have the potential to 
disturb or displace marine mammals. Specifically, the project 
activities may result in take, in the form of Level A and Level B 
harassment from underwater sounds generated from pile driving and 
removal and DTH. Potential takes could occur if individuals are present 
in the ensonified zone when these activities are underway.
    The takes from Level A and Level B harassment would be due to 
potential behavioral disturbance, TTS, and PTS. No serious injury or 
mortality is anticipated given the nature of the activity and measures 
designed to minimize the possibility of injury to marine mammals. The 
potential for harassment is minimized through the construction method 
and the implementation of the planned mitigation measures (see 
Mitigation section).
    The Level A harassment zones identified in Table 4 are based upon 
an animal exposed to impact pile driving multiple piles per day. 
Considering the short duration to impact drive or DTH each pile and 
breaks between pile installations (to reset equipment and move pile 
into place), this means an animal would have to remain within the area 
estimated to be ensonified above the Level A harassment threshold for 
multiple hours. This is highly unlikely given marine mammal movement 
throughout the area. If an animal was exposed to accumulated sound 
energy, the resulting PTS would likely be small (e.g., PTS onset) at 
lower frequencies where pile driving energy is concentrated, and 
unlikely to result in impacts to individual fitness, reproduction, or 
survival.
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. For all species and stocks, take would 
occur within a limited, confined area (adjacent to the CBBT) of the 
stock's range. Level A and Level B harassment will be reduced to the 
level of least practicable adverse impact through use of mitigation 
measures described herein. Further the

[[Page 67034]]

amount of take authorized is extremely small when compared to stock 
abundance.
    Behavioral responses of marine mammals to pile driving at the 
project site, if any, are expected to be mild and temporary. Marine 
mammals within the Level B harassment zone may not show any visual cues 
they are disturbed by activities (as noted during modification to the 
Kodiak Ferry Dock) or could become alert, avoid the area, leave the 
area, or display other mild responses that are not observable such as 
changes in vocalization patterns. Given the short duration of noise-
generating activities per day, any harassment would be temporary. There 
are no other areas or times of known biological importance for any of 
the affected species.
    We acknowledge the existence and concern about the ongoing humpback 
whale UME. We have no evidence that this project is likely to result in 
vessel strikes (a major correlate of the UME) and marine construction 
projects in general involve the use of slow-moving vessels, such as 
tugs towing or pushing barges, or smaller work boats maneuvering in the 
vicinity of the construction project. These vessel types are not 
typically associated with vessel strikes resulting in injury or 
mortality. More generally, the UME does not yet provide cause for 
concern regarding population-level impacts for humpback whales. Despite 
the UME, the West Indies breeding population or DPS, remains healthy.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on the stocks' ability 
to recover. In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activities will 
have only minor, short-term effects on individuals. The specified 
activities are not expected to impact rates of recruitment or survival 
and will therefore not result in population-level impacts.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     Authorized Level A harassment would be very small amounts 
and of low degree;
     No important habitat areas have been identified within the 
project area;
     For all species, Chesapeake Bay is a very small and 
peripheral part of their range;
     CTJV would implement mitigation measures such as bubble 
curtains, soft-starts, and shut downs; and
     Monitoring reports from similar work in Chesapeake Bay 
have documented little to no effect on individuals of the same species 
impacted by the specified activities.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed 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 section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. When the predicted number of individuals to 
be taken is fewer than one third of the species or stock abundance, the 
take is considered to be of small numbers. Additionally, other 
qualitative factors may be considered in the analysis, such as the 
temporal or spatial scale of the activities.
    The amount of take NMFS proposes to authorize is below one third of 
the estimated stock abundance for humpback whale, harbor porpoise, gray 
seal, harbor seal (in fact, take of individuals is less than 10 percent 
of the abundance of the affected stocks, see Table 4). This is likely a 
conservative estimate because they assume all takes are of different 
individual animals which is likely not the case. Some individuals may 
return multiple times in a day, but PSOs would count them as separate 
takes if they cannot be individually identified.
    There are three bottlenose dolphin stocks that could occur in the 
project area. Therefore, the estimated 86,656 dolphin takes by Level B 
harassment would likely be split among the western North Atlantic 
northern migratory coastal stock, western North Atlantic southern 
migratory coastal stock, and NNCES stock. Based on the stocks' 
respective occurrence in the area, NMFS estimated that there would be 
no more than 250 takes from the NNCES stock, representing 30.4 percent 
of that population, with the remaining takes split evenly between the 
northern and southern migratory coastal stocks. Based on consideration 
of various factors described below, we have determined the numbers of 
individuals taken would comprise less than one-third of the best 
available population abundance estimate of either coastal migratory 
stock. Detailed descriptions of the stocks' ranges have been provided 
in Description of Marine Mammals in the Area of Specified Activities.
    Both the northern migratory coastal and southern migratory coastal 
stocks have expansive ranges and they are the only dolphin stocks 
thought to make broad-scale, seasonal migrations in coastal waters of 
the western North Atlantic. Given the large ranges associated with 
these two stocks it is unlikely that large segments of either stock 
would approach the project area and enter into the Chesapeake Bay. The 
majority of both stocks are likely to be found widely dispersed across 
their respective habitat ranges and unlikely to be concentrated in or 
near the Chesapeake Bay.
    Furthermore, the Chesapeake Bay and nearby offshore waters 
represent the boundaries of the ranges of each of the two coastal 
stocks during migration. The northern migratory coastal stock is found 
during warm water months from coastal Virginia, including the 
Chesapeake Bay and Long Island, New York. The stock migrates south in 
late summer and fall. During cold-water months dolphins may be found in 
coastal waters from Cape Lookout, North Carolina, to the North 
Carolina/Virginia. During January-March, the southern migratory coastal 
stock appears to move as far south as northern Florida. From April to 
June, the stock moves back north to North Carolina. During the warm 
water months of July-August, the stock is presumed to occupy coastal 
waters north of Cape Lookout, North Carolina, to Assateague, Virginia, 
including the Chesapeake Bay. There is likely some overlap between the 
northern and southern migratory stocks during spring and fall 
migrations, but the extent of overlap is unknown.
    The Bay and waters offshore of the mouth are located on the 
periphery of the migratory ranges of both coastal stocks (although 
during different seasons). Additionally, each of the migratory coastal 
stocks are likely to be located in the vicinity of the Bay for 
relatively short timeframes. Given the

[[Page 67035]]

limited number of animals from each migratory coastal stock likely to 
be found at the seasonal migratory boundaries of their respective 
ranges, in combination with the short time periods (~2 months) animals 
might remain at these boundaries, it is reasonable to assume that takes 
are likely to occur only within some small portion of either of the 
migratory coastal stocks.
    Both migratory coastal stocks likely overlap with the NNCES stock 
at various times during their seasonal migrations. The NNCES stock is 
defined as animals that primarily occupy waters of the Pamlico Sound 
estuarine system (which also includes Core, Roanoke, and Albemarle 
sounds, and the Neuse River) during warm water months (July-August). 
Members of this stock also use coastal waters (<=1 kilometer from 
shore) of North Carolina from Beaufort north to Virginia Beach, 
Virginia, including the lower Chesapeake Bay. Comparison of dolphin 
photo-identification data confirmed that limited numbers of individual 
dolphins observed in Roanoke Sound have also been sighted in the 
Chesapeake Bay (Young, 2018). Like the migratory coastal dolphin 
stocks, the NNCES stock covers a large range. The spatial extent of 
most small and resident bottlenose dolphin populations is on the order 
of 500 km\2\, while the NNCES stock occupies over 8,000 km\2\ 
(LeBrecque et al., 2015). Given this large range, it is again unlikely 
that a preponderance of animals from the NNCES stock would depart the 
North Carolina estuarine system and travel to the northern extent of 
the stock's range and enter into the Bay. However, recent evidence 
suggests that there is likely a small resident community of NNCES 
dolphins of indeterminate size that inhabits the Chesapeake Bay year-
round (Eric Patterson, Personal Communication).
    Many of the dolphin observations in the Bay are likely repeated 
sightings of the same individuals. The Potomac-Chesapeake Dolphin 
Project has observed over 1,200 unique animals since observations began 
in 2015. Re-sightings of the same individual can be highly variable. 
Some dolphins are observed once per year, while others are highly 
regular with greater than 10 sightings per year (Mann, Personal 
Communication). Similarly, using available photo-identification data, 
Engelhaupt et al. (2016) determined that specific individuals were 
often observed in close proximity to their original sighting locations 
and were observed multiple times in the same season or same year. 
Ninety-one percent of re-sighted individuals (100 of 110) in the study 
area were recorded less than 30 km from the initial sighting location. 
Multiple sightings of the same individual would considerably reduce the 
number of individual animals that are taken by harassment. Furthermore, 
the existence of a resident dolphin population in the Bay would 
increase the percentage of dolphin takes that are actually re-sightings 
of the same individuals.
    Monitoring reports and data from prior years of the project work 
have recorded less than 10 level B takes of bottlenose dolphins in over 
100 days of monitored pile driving.
    In summary and as described above, the following factors primarily 
support our determination regarding the incidental take of small 
numbers of a species or stock:
     The take of marine mammal stocks authorized for take 
comprises less than 10 percent of any stock abundance (with the 
exception of bottlenose dolphin stocks);
     Potential bottlenose dolphin takes in the project area are 
likely to be allocated among three distinct stocks;
     Bottlenose dolphin stocks in the project area have 
extensive ranges and it would be unlikely to find a high percentage of 
any one stock concentrated in a relatively small area such as the 
project area or the Bay;
     The Bay represents the migratory boundary for each of the 
specified dolphin stocks and it would be unlikely to find a high 
percentage of any stock concentrated at such boundaries;
     Monitoring from prior years found less than 10 level B 
takes of bottlenose dolphin in over 100 days of monitored pile driving; 
and
     Many of the takes would be repeats of the same animal and 
it is likely that a number of individual animals could be taken 10 or 
more times.
    Based on the analysis contained herein of the proposed activity 
(including the proposed 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

    Section 7(a)(2) of the ESA (16 U.S.C. 1531 et seq.) requires that 
each Federal agency insure that any action it authorizes, funds, or 
carries out is not likely to jeopardize the continued existence of any 
endangered or threatened species or result in the destruction or 
adverse modification of designated critical habitat. To ensure ESA 
compliance for the issuance of IHAs, NMFS consults internally whenever 
we propose to authorize take for endangered or threatened species.
    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 CTJV for the potential harassment of 
small numbers of five marine mammal species incidental to conduct the 
PTST Project in Virginia Beach, Virginia for one year from the date of 
issuance, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are followed.

    Dated: November 18, 2021.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2021-25627 Filed 11-23-21; 8:45 am]
BILLING CODE 3510-22-P