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Notice2021-25627

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

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Published

November 24, 2021

Issuing agencies

Commerce DepartmentNational Oceanic and Atmospheric Administration

Abstract

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.

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[Federal Register Volume 86, Number 224 (Wednesday, November 24, 2021)]
[Notices]
[Pages 67024-67035]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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: <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>. 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, <a href="https://media.fisheries.noaa.gov/2021-10/Draft%202021%20NE%">https://media.fisheries.noaa.gov/2021-10/Draft%202021%20NE%</a> 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 (<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general
information about these species (e.g., physical and behavioral
descriptions) may be found on NMFS's website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
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
--------------------------------------------------------------------------------------------------------------------------------------------------------
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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>. 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 (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) 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 (<a href="https://media.fisheries.noaa.gov/dam-migration/ctjvthimbleshoals_final_ssv_report_opr1_3-23.pdf">https://media.fisheries.noaa.gov/dam-migration/ctjvthimbleshoals_final_ssv_report_opr1_3-23.pdf</a>) 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 <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.

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 (<a href="https://media.fisheries.noaa.gov/dam-migration/ctjvthimbleshoals_final_ssv_report_opr1_3-23.pdf">https://media.fisheries.noaa.gov/dam-migration/ctjvthimbleshoals_final_ssv_report_opr1_3-23.pdf</a>) 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:
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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
<bullet> 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:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> 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);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> 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.
<bullet> 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:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> 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
<bullet> 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
<bullet> 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]]

<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> 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);
<bullet> PSO locations during marine mammal monitoring;
<bullet> 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;
<bullet> 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);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> 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)
(<a href="/cdn-cgi/l/email-protection#91c1c3bfd8c5c1bfdcfefff8e5fee3f8fff6c3f4e1fee3e5e2d1fffef0f0bff6fee7"><span class="__cf_email__" data-cfemail="91c1c3bfd8c5c1bfdcfefff8e5fee3f8fff6c3f4e1fee3e5e2d1fffef0f0bff6fee7">[email&#160;protected]</span></a>), 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:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> 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:
<bullet> No mortality is anticipated or authorized;
<bullet> Authorized Level A harassment would be very small amounts
and of low degree;
<bullet> No important habitat areas have been identified within the
project area;
<bullet> For all species, Chesapeake Bay is a very small and
peripheral part of their range;
<bullet> CTJV would implement mitigation measures such as bubble
curtains, soft-starts, and shut downs; and
<bullet> 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:
<bullet> 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);
<bullet> Potential bottlenose dolphin takes in the project area are
likely to be allocated among three distinct stocks;
<bullet> 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;
<bullet> 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;
<bullet> Monitoring from prior years found less than 10 level B
takes of bottlenose dolphin in over 100 days of monitored pile driving;
and
<bullet> 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

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