[Federal Register Volume 85, Number 55 (Friday, March 20, 2020)]
[Notices]
[Pages 16061-16077]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-05802]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XR035]


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 take, by 
Level A harassment and Level B harassment, five species of marine 
mammals during the Parallel Thimble Shoal Tunnel Project (PTST) in 
Virginia Beach, Virginia.

DATES: This Authorization is effective from March 10, 2020 through 
March 09, 2021.

FOR FURTHER INFORMATION CONTACT: Robert Pauline, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than

[[Page 16062]]

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

Summary of Request

    On May 24, 2019, NMFS received a request from the CTJV for an IHA 
to take marine mammals incidental to pile driving and removal at the 
Chesapeake Bay Bridge and Tunnel (CBBT) near Virginia Beach, Virginia. 
The application was deemed adequate and complete on October 11, 2019. 
The CTJV's request is for take of small numbers of harbor seal (Phoca 
vitulina), gray seal (Halichoerus grypus), bottlenose dolphin (Tursiops 
truncatus), harbor porpoise (Phocoena phocoena) and humpback whale 
(Megaptera novaeangliae) by Level A and Level B harassment. Neither the 
CTJV nor NMFS expects serious injury or mortality to result from this 
activity and, therefore, an IHA is appropriate.

Description of Activity

Overview

    The CTJV requested authorization for take of marine mammals 
incidental to in-water construction activities associated with the PTST 
project. The project consists of the construction of a two-lane 
parallel tunnel to the west of the existing Thimble Shoal Tunnel, 
connecting Portal Island Nos. 1 and 2 of the CBBT facility which 
extends across the mouth of the Chesapeake Bay near Virginia Beach, 
Virginia. Upon completion, the new tunnel will carry two lanes of 
southbound traffic and the existing tunnel will remain in operation and 
carry two lanes of northbound traffic. The PTST project will address 
existing constraints to regional mobility based on current traffic 
volume along the facility. Construction will include the installation 
and removal of 812 piles over 198 days as shown below in Table 1. Due 
to minor construction design changes, the Federal Register notice 
announcing the proposed IHA (84 FR 64847; November 25, 2019), had 
originally estimated that there were would be 878 piles installed and 
removed over 188 days.
    In-water activities associated with the project include impact 
driving, vibratory driving and drilling with down-the-hole (DTH) 
hammers. Some piles will be removed via vibratory hammer. Work will 
occur during standard daylight hours of approximately 8-12 hours per 
day depending on the season. In-water work will occur every month with 
the exception of February 2021. In-water construction associated with 
this IHA will begin in winter of 2020.
    The PTST project has been divided into four phases over 5 years. 
Phase I commenced in June 2017 and consisted of upland pre-tunnel 
excavation activities, while Phase IV is scheduled to be completed in 
May of 2022. In-water activities are limited to Phase II and, 
potentially, Phase IV (if substructure repair work is required at the 
fishing pier and/or bridge trestles and abutments). Take of marine 
mammals authorized under this IHA will occur for one year from the date 
of issuance.
    A detailed description of the planned activities is provided in the 
Federal Register notice announcing the proposed IHA (84 FR 64847; 
November 25, 2019). Since that time the CTJV has made minor revisions 
to the project's construction schedule. The project is now planned to 
occur over 11 months with no in-water activity in February 2021. The 
project schedule contained in the proposed IHA was to occur over 10 
months with no in-water work during September and October of 2020. The 
in-water activities described in the proposed IHA Federal Register 
notice generally remain the same. Any changes from the proposed IHA 
Federal Register notice are identified in this notice. Therefore, a 
detailed description is not provided here. Please refer to the proposed 
IHA Federal Register notice for a detailed description of the activity.

                                            Table 1--Pile Driving Activities Associated With the PTST Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                       Number of days
                                                                                       Bubble   Number of  Number of    per activity       Anticipated
        Pile location            Pile function       Pile type       Installation/    curtain     piles     days per     (per hammer      installation
                                                                    removal method    (yes/no)  below MHW   activity     type) full           date
                                                                                                            (total)      production
--------------------------------------------------------------------------------------------------------------------------------------------------------
Portal Island No. 1..........  Mooring dolphins  12-inch Timber    Vibratory                No        120         18  18 Days (7 Piles/ 1 May 2020
                                                  piles.            (Install).              No  .........  .........   Day).             through 20 June
                                                                   Impact (if                                         14 Days (9 Piles/  2020.
                                                                    needed).                                           Day)..
Portal Island No. 1..........  Temporary Dock..  42-inch Diameter  DTH (install)...         No         58         20  20 Days (3 Piles/ 7 Feb 2019
                                                  Steel Pipe       Vibratory                No  .........  .........   day).             through 7 June
                                                  Casing *.         (removal).                                        10 Days (6 Piles/  2020.
                                                                                                                       day)..
                                                 36-inch Diameter  Impact..........        Yes  .........         20  20 Days (3 Piles/
                                                  Steel Pipe Pile.                                                     day).
Portal Island No. 1..........  Omega Trestle...  36-inch Diameter  DTH (Install)...         No         18          9  9 Days (2 Piles/  7 Feb 2020
                                                  Steel Pipe       Impact..........        Yes  .........  .........   Day).             through 28
                                                  Piles.                                                              6 Days (3 Piles/   April 2020.
                                                                                                                       Day)..
Portal Island No. 1..........  Berm Support of   36-inch Diameter  DTH (install)...         No        133         27  27 Days (5 Piles/ 7 Feb 2020
                                Excavation        Steel            Impact..........        Yes  .........  .........   Day.              through 1 June
                                Wall--West Side.  Interlocked                                                         13 Days (10        2020.
                                                  Pipe Piles.                                                          Piles/Day)..
Portal Island No. 1..........  Berm Support of   36-inch Diameter  DTH (Install)...         No        121         25  25 Days (5 Piles/ 7 Feb 2020
                                Excavation        Steel            Impact..........        Yes  .........  .........   Day).             through 1
                                Wall--East Side.  Interlocked                                                         12 Days (10        September 2020.
                                                  Pipe Piles.                                                          Piles/Day)..
Portal Island No. 1..........  Mooring Piles     36-inch Diameter  Vibratory                No         12          3  3 Days (5 Piles/  7 Feb 2020
                                and Templates.    Steel Pipe        (Install &                                         Day).             through 31
                                                  Piles.            Removal).                                                            October 2020.
Portal Island No. 2..........  Mooring Dolphins  12-inch Timber    Vibratory                No         60          9  9 Days (7 Piles/  20 June 2020
                                                  Piles.            (Install).              No  .........  .........   Day).             through 1
                                                                   Impact (if                                         7 Days (9 Piles/   August 2020.
                                                                    needed).                                           Day)..
Portal Island No. 2..........  Omega Trestle...  36-inch Diameter  DTH (Install)...         No         28         14  14 Days (2 Piles/ 1 June 2020
                                                  Steel Pipe       Impact..........        Yes  .........  .........   Day).             through 30
                                                  Piles.                                                              12 Days (3 Piles/  September 2020.
                                                                                                                       Day)..
Portal Island No. 2..........  Berm Support of   36-inch Diameter  DTH (Install)...         No        124         25  25 Days ( 5       1 July 2020
                                Excavation        Steel            Impact..........        Yes  .........  .........   Piles/Day).       through 6 Feb
                                Wall--West Side.  Interlocked                                                         13 Days (10        2021.
                                                  Pipe Piles.                                                          Piles/Day)..

[[Page 16063]]

 
Portal Island No. 2..........  Berm Support of   36-inch Diameter  DTH (Install)...         No        122         25  25 Days (5 Piles/ 10 September
                                Excavation        Steel            Impact..........        Yes  .........  .........   Day).             2020 through 6
                                Wall--East Side.  Interlocked                                                         13 Days (10        Feb 2021.
                                                  Pipe Piles.                                                          Piles/Day)..
Portal Island No. 2..........  Mooring Piles     36-inch Diameter  Vibratory                No         16          3  3 Days (6 Piles/  1 March 2020
                                and Templates.    Steel Pipe        (Install &                                         Day).             through 31
                                                  Piles.            Removal).                                                            October 2020.
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Total.....................................................................................  812 Piles   198 Days
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Mitigation, monitoring, and reporting measures are described in 
detail later in this document (please see Mitigation and Monitoring and 
Reporting sections).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to the CTJV was 
published in the Federal Register on November 25, 2019 (84 FR 64847). 
That notice described, in detail, the CTJV's planned activity, the 
marine mammal species that may be affected by the activity, the 
anticipated effects on marine mammals and their habitat, proposed 
amount and manner of take, and proposed mitigation, monitoring and 
reporting measures. During the 30-day public comment period NMFS 
received a comment letter from the Marine Mammal Commission 
(Commission). The Commission's recommendations and our responses are 
provided here, and the comments have been posted online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
    Comment 1: The Commission recommends that NMFS refrain from 
publishing for public comment proposed incidental harassment 
authorizations which contain errors and inconsistencies in the basic 
underlying information and instead return such applications to action 
proponents as incomplete.
    Response: NMFS thanks the Commission for its recommendation. NMFS 
reviews the notices thoroughly prior to publication and, despite 
certain errors noted by the Commission, publishes (in this case and 
others) proposals that are based on the best scientific evidence 
available and that are sufficient to facilitate public comment on our 
proposed actions under the MMPA.
    Comment 2: The Commission recommended that NMFS resolve differences 
between Table 1 and Table 7 in the proposed IHA concerning the number 
of piles driven per day
    Response: The CTJV revised the project schedule and has arrived at 
812 total piles driven and removed over 198 days of driving operations 
as shown in Table 1 in this notice.
    Comment 3: The Commission recommended that NMFS refrain from 
reducing the number of piles to be installed/removed per day by 50 
percent in order to calculate take by Level A harassment. If NMFS 
intends to use a 50-percent reduction in the number of piles to be 
installed/removed per day, the Commission recommended that NMFS 
implement that reduction consistently for all pile sizes, types, and 
installation/removal methods.
    Response: For purposes of estimated take by Level A harassment, 
NMFS assumed that the number of piles installed on a given day was 50 
percent of the total planned number. Since the marine mammals proposed 
for authorization are highly mobile, it is unlikely that an animal 
would remain within an established Level A harassment zone during the 
installation/removal of multiple piles throughout a given day. To 
provide a more realistic estimate of take by Level A harassment, NMFS 
assumed that an animal would occur within the injury zone for 50 
percent of the driving time, which equates to 50 percent of the piles 
planned for installation/removal. NMFS acknowledges the necessity of 
implementing this reduction across all pile sizes, types, and 
installation/removal methods and has done so as shown in Table 5.
    Comment 4: In the absence of relevant recovery time data for marine 
mammals, the Commission recommended that animat modeling be used to 
inform the appropriate accumulation time to determine injury isopleths 
and estimate takes by Level A harassment. The Commission also 
recommended that NMFS continue to make this issue a priority to resolve 
in the near future and consider incorporating animat modeling into its 
user spreadsheet.
    Response: NMFS appreciates the Commission's interest in this issue, 
and considers the issue a priority.
    Comment 5: The Commission recommends that NMFS consult with 
acousticians regarding the appropriate source level reduction factor to 
use to minimize near-field (<100 m) and far-field (>100 m) effects on 
marine mammals or use the data NMFS has compiled regarding source level 
reductions at 10 m for near-field effects and assume no source level 
reduction for far-field effects for all relevant incidental take 
authorizations.
    Response: NMFS disagrees with the Commission regarding this issue, 
and does not adopt the recommendation. The Commission has raised this 
concern before and NMFS refers readers to our full response, which may 
be found in a previous notice of issuance of an IHA (84 FR 64833, 
November 25, 2019).
    Comment 6: The Commission recommended that NMFS use the untruncated 
seasonal densities for bottlenose dolphins from Engelhaupt et al. 
(2016), consistent with the previous authorization and the July 2019 
monitoring data, to estimate the numbers of Level B harassment takes.
    Response: NMFS has accepted the Commission's recommendation and 
will use untruncated data from Engelhaupt et al. (2016) to estimate 
take of bottlenose dolphins as shown in Table 9 of this notice of 
issuance.
    Comment 7: The Commission reiterates programmatic recommendations 
regarding NMFS' potential use of the renewal mechanism for one-year 
IHAs.
    Response: NMFS disagrees with the Commission's recommendations, as 
stated in our previous comment responses relating to other actions, 
which we incorporate here by reference (e.g., 84 FR 52464; October 2, 
2019).

Changes From the Proposed IHA to the Final IHA

    Stock abundance updates to Table 2 (Marine Mammal Species Likely To 
Occur Near the Project Area) were made in this notice for North 
Atlantic right whale, fin whale, the coastal southern migratory stock 
of bottlenose dolphin, harbor porpoise, and humpback whale based on the 
2019 draft Stock Assessment Report published on November 27, 2019 (84 
FR 65353).

[[Page 16064]]

    NMFS indicated in the Federal Register notice that the IHA would 
cover in-water activities beginning in the fall 2019. However, 
activities will not begin until the authorization is issued in winter 
2019. NMFS also indicated in the proposed IHA Federal Register notice 
that up to 888 piles would be driven and/or removed. The CTJV has since 
clarified that 812 piles will be driven and/or removed over 198 days 
during the effective period of the issued IHA. The construction 
schedule has been revised and now includes in-water activity over 11 
months, with none in February, instead of 10 months of activity, with 
none in September or October as indicated in the proposed IHA Federal 
Register notice. Additionally, there will be no vibratory removal of 
12-in timber piles as described in the proposed IHA. Temporary 12-in 
timber piles will either be cut off at the mudline or undergo vibratory 
removal as part of future work for which a separate IHA may be 
requested. While vibratory installation of timber piles will occur, 
there are no references to vibratory removal of 12-in timber piles in 
this Federal Register notice of issuance.
    NMFS indicated in the proposed Federal Register notice that the 
source level for impact driving of 12-in piles originated from the 
Ballena project described in Caltrans (2015). However, that referenced 
source level came from only a single pile. The correct source levels 
according to Caltrans (2015) are 180 dB re 1 [mu]Pa peak, 170 dB re 1 
[mu]Pa rms, and 160 dB re 1 [mu]Pa2-sec at 10 m. NMFS has included the 
updated information in Table 4 and Table 5 of this notice and updated 
the Level A and B harassment zones and numbers of takes accordingly. 
NMFS incorrectly specified in Table 9 of the proposed IHA Federal 
Register notice the Level B harassment zone for impact installation of 
36-in piles as 1,555 m rather than 1,585 m and for vibratory 
installation/removal of 12-in timber piles as 1,354 m rather than 1,359 
m. NMFS has made the appropriate corrections to Table 7 of this notice 
and revised numbers of takes accordingly.
    NMFS has included in the issued IHA a requirement that at least two 
protected species observers (PSOs) will be required to monitor before, 
during, and after the proposed pile-driving and -removal activities.
    NMFS has included language requiring extrapolation of the numbers 
of Level A harassment takes in the issued IHA as well Level B 
harassment takes based on the extents of the zones that could be 
monitored. Finally, take numbers for all authorized species have been 
revised and are described in the Estimated Take section and listed in 
Table 10.

Description of Marine Mammals in the Area of Specified Activities

    Table 2 lists all species with expected potential for occurrence 
near the project area and summarizes information related to the 
population or stock, including regulatory status under the MMPA and ESA 
and potential biological removal (PBR), where known. For taxonomy, we 
follow Committee on Taxonomy (2019). 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.
    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 2018 United States Atlantic and Gulf of Mexico Marine Mammal 
Stock Assessments (Hayes et al. 2019) and draft 2019 United States 
Atlantic and Gulf of Mexico Marine Mammal Stock Assessments published 
in the Federal Register on November 27, 2019 (84 FR 65353). All values 
presented in Table 2 are the most recent available at the time of 
publication and are available in the 2018 SAR and draft 2019 SAR.

                                          Table 2--Marine Mammal Species Likely To Occur Near the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance  (CV,
             Common name                  Scientific name               Stock            strategic  (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
North Atlantic right whale \5\......  Eubalaena glacialis....  Western North Atlantic   E, D; Y             428 (0, 418; See SAR).        0.8       5.55
                                                                (WNA).
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Gulf of Maine..........  -,-; N              1,380 (0; 1,380, see           22      12.15
                                                                                                             SAR).
    Fin whale \5\...................  Balaenoptera physalus..  WNA....................  E,D; Y              7,418 (0.25; 6,029;            12       2.35
                                                                                                             See SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin..............  Tursiops truncatus.....  WNA Coastal, Northern    -,-; Y              6,639 (0.41; 4,759;            48   6.1-13.2
                                                                Migratory.                                   2011).
                                      .......................  WNA Coastal, Southern    -,-; Y              3,751 (0.06; 2,353;            23     0-14.3
                                                                Migratory.                                   2011).
                                      .......................  Northern North Carolina  -,-; Y              823 (0.06; 782; See           7.8   0.8-18.2
                                                                Estuarine System.                            SAR).
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of     -, -; N             95,543 (0.31; 74,034;         851        217
                                                                Fundy.                                       See SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 16065]]

 
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  WNA....................  -; N                75,834 (0.1; 66,884,        2,006        350
                                                                                                             2012).
    Gray seal \4\...................  Halichoerus grypus.....  WNA....................  -; N                27,131 (0.19, 23,158,       1,359      5,410
                                                                                                             See SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable
\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 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.
\5\ Species are not expected to be taken or authorized for take.

    A detailed description of the of the species likely to be affected 
by the planned 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 (84 FR 64847; November 25, 2019) for additional 
information. Since that time the draft 2019 United States Atlantic and 
Gulf of Mexico Marine Mammal Stock Assessments has been released (84 FR 
65353; November 27, 2019). Updates from the draft SAR have been 
incorporated for the North Atlantic right whale, fin whale, the coastal 
southern migratory stock of bottlenose dolphin, harbor porpoise, and 
humpback whale. We are not aware of any additional 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

    Underwater noise from impact pile driving, vibratory pile driving, 
vibratory pile removal, and drilling with a DTH hammer associated with 
the PTST project have the potential to result in harassment of marine 
mammals in the vicinity of the action area. The Federal Register notice 
for the proposed IHA (84 FR 64847; November 25, 2019) included a 
discussion of the potential effects of such disturbances on marine 
mammals and their habitat, therefore that information is not repeated 
in detail here; please refer to the Federal Register notice (84 FR 
64847; November 25, 2019) for that information.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which informs 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 will primarily be by Level B harassment, as use of 
the acoustic sources (i.e., pile driving, DTH drilling) has the 
potential to result in disruption of behavioral patterns for individual 
marine mammals. There is also some potential for auditory injury (Level 
A harassment) to result, for phocids (harbor seals, gray seals) mid-
frequency species (bottlenose dolphins) and high-frequency species 
(harbor porpoises) due to the size of the predicted auditory injury 
zones. The planned mitigation and monitoring measures (see Mitigation 
and Monitoring and Reporting sections below) are expected to minimize 
the severity of such 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 NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the 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). Below, we describe the 
factors considered here in more detail and present the take estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed 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

[[Page 16066]]

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 [mu]Pa (rms) for continuous (e.g., vibratory pile-driving) and 
above 160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., 
seismic airguns) or intermittent (e.g., scientific sonar) sources. The 
CTJV's planned activity includes the use of continuous (vibratory pile 
driving) and impulsive (impact pile driving, DTH drilling) sources, and 
therefore the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are 
applicable.
    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). The CTJV's planned activity includes the 
use includes the use of continuous (vibratory pile driving) and 
impulsive (impact pile driving, DTH drilling) sources.
    These thresholds are provided in Table 3 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218       Cell 8: LE,PW,24h: 201 dB.
                                          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 planned project. Pile 
driving generates underwater noise that can potentially result in 
disturbance to marine mammals in the project area. The maximum 
(underwater) area ensonified is determined by the topography of the Bay 
including shorelines to the west south and north as well as by hard 
structures such as portal islands.
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log 10 (R 1/R 2),

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

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]). A 
practical spreading value of 15 is often used under conditions, such as 
the PTST project site where water generally increases with depth as the 
receiver moves away from pile driving locations, resulting in an 
expected propagation environment that would lie between spherical and 
cylindrical spreading loss conditions. Practical spreading loss is 
assumed here.
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. In order to calculate 
distances to the Level A harassment and Level B harassment thresholds 
for the 36-inch steel piles planned in this project, the CTJV used 
acoustic monitoring data from other locations as described in Caltrans 
2015 for impact and vibratory driving. The CTJV also conducted their

[[Page 16067]]

own sound source verification testing on 42-inch steel casings as 
described below to determine source levels associated with DTH 
drilling. NMFS used vibratory driving of 36-in steel pile source levels 
for vibratory driving of 42-inch casings source levels. The CTJV plans 
to employ bubble curtains during impact driving of 36-inch steel piles 
and, therefore, reduced the source level by 7 dB (a conservative 
estimate based on several studies including Austin et al. 2016).
    Source levels for drilling with a DTH hammer were field verified at 
the PTST project site by JASCO Applied Sciences in July 2019 (Denes, 
2019). Underwater sound levels were measured during drilling with a DTH 
hammer at five pile locations--three without bubble curtain attenuation 
and two with bubble curtain attenuation. The average SPL value at 10 m 
for the DTH location without a bubble curtain was 180 dB re 1[mu]Pa, 
while the average SEL and PK levels were 164 dB re 1[mu]Pa2[middot]s 
and 190 dB re 1[mu]Pa, respectively. These values were greater than DTH 
testing done at a location in Alaska (Denes et al. 2016). The dominant 
signal characteristic was also found to be impulsive rather than 
continuous. Southall et al. (2007) suggested that impulsive sounds can 
be distinguished from non-impulsive sounds by comparing the SPL of a 
0.035 s window that includes the pulse and with a 1 s window that may 
include multiple pulses. If the SPL of the 0.035 s window is 3 dB 
greater than the 1 s window, then the signal should be considered 
impulsive. Denes (2019) observed that at the PTST site, the SPL of the 
0.035 s pulse is 5 dB higher than the SPL of the 1 s sample, so the DTH 
source is classified here as impulsive. Source levels associated with 
DTH drilling of 42-inch steel casings were assumed to be the same as 
recorded for installation of 36-in steel pipe by DTH.
    The CTJV utilized in-water measurements generated by the Greenbusch 
Group (2018) from the WSDOT Seattle Pier 62 project (83 FR 39709) to 
establish proxy sound source levels for vibratory installation of 12-
inch timber piles. NMFS reviewed the report by the Greenbusch Group 
(2018) and determined that the findings were derived by pooling 
together all steel pile and timber pile at various distance 
measurements data together. The data was not normalized to the standard 
10 m distance. NMFS analyzed source measurements at different distances 
for all 63 individual timber piles that were removed and normalized the 
values to 10 m. The results showed that the median is 152 dB SPLrms. 
This value was used as the source level for vibratory installation of 
12-inch timber piles. Source levels for impact driving of 12-in timber 
piles were from the Ballena Bay Marina project in Alameda, CA as 
described in Caltrans 2015 but have been revised in this document. The 
lower values contained in the proposed IHA notice were from a single 
pile at the Ballena Bay Marina and did not reflect the measurements 
from all of the piles that were tested. Sound source levels used to 
calculate take are shown in Table 4.

                                     Table 4--The Sound Source Levels (dB Peak, dB RMS, and dB sSEL) by Hammer Type
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Estimated
                                                                                              single
                                                                  Estimated    Estimated      strike
             Type of pile                     Hammer type         peak noise    pressure      sound      Relevant piles  at the       Pile function
                                                                  level  (dB   level  (dB    exposure        PTST  project
                                                                    peak)         RMS)      level  (dB
                                                                                              sSEL)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch Steel Pipe...................  Impact \a\..............          210          193          183  Plumb..................  Omega Trestle,
                                                                                                                                  Temporary Dock, Berm
                                                                                                                                  Wall West, and Berm
                                                                                                                                  Wall East.
                                       Impact with Bubble                203          186          176  Plumb..................  Berm Wall West, Berm
                                        Curtain \b\.                                                                              Wall East, and
                                                                                                                                  Temporary Dock.
                                       DTH--Impulsive \d\......          190          180          164  Plumb..................  Omega Trestle, Berm
                                                                                                                                  Wall West, and Berm
                                                                                                                                  Wall East.
                                       Vibratory \a\...........           NA          170          170  Pipe Piles.............  Mooring Piles and
                                                                                                                                  Templates.
12-inch Timber Pile..................  Vibratory \c\...........           NA          152          152  Plumb..................  Mooring Dolphins.
                                       Impact \a\..............          180          170          160  Plumb..................  Mooring Dolphins.
42-inch Steel Casing.................  DTH--Impulsive \d\......          190          180          164  Steel Casing...........  Temporary Dock.
                                       Vibratory \a\...........           NA          170          170  Pipe Piles.............  Temporary Dock.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: sSEL = Single Strike Exposure Level; dB = decibel; N/A = not applicable.
\a\ Caltrans 2015.
\b\ 7 dB reduction was assumed for use an encased bubble curtain (Austin et al. 2016).
\c\ Greenbusch Group 2018.
\d\ Denes et al. 2019.

    The CTJV used NMFS' Optional User Spreadsheet, available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance, to input project-specific 
parameters and calculate the isopleths for the Level A harassment zones 
for impact and vibratory pile driving. 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 Level A 
harassment take. However, these tools offer the best way to predict 
appropriate isopleths when more sophisticated 3D modeling methods are 
not available, and NMFS continues to develop ways to quantitatively 
refine these tools, and will qualitatively address the output where 
appropriate. For stationary source pile driving, the NMFS User 
Spreadsheet predicts the distance at which, if a marine mammal remained 
at that distance the whole duration of the activity, it would incur 
PTS.
    Table 5 provides the sound source values and input employed in the 
User Spreadsheet to calculate harassment isopleths for each source type 
while

[[Page 16068]]

Table 6 shows distances to Level A harassment isopleths. Note that the 
isopleths calculated using the planned number of piles driven per day 
is conservative. PTS is based on accumulated exposure over time. 
Therefore, an individual animal would have to be within the calculated 
PTS zones when all of the piles of a single type and driving method are 
being actively installed throughout an entire day. The marine mammals 
authorized for take are highly mobile. It is unlikely that an animal 
would remain within the PTS zone during the installation of, for 
example, 10 piles over an 8-hour period. NMFS opted to reduce the 
number of piles driven per day by 50 percent in order to derive more 
realistic PTS isopleths. In cases where the number of planned piles per 
day was an odd number, NMFS used the next largest whole number that was 
greater than 50 percent. These are shown in Table 5 in the row with the 
heading Number of piles/day. Table 6 contains calculated distances to 
PTS isopleths and Table 7 depicts distances to Level B harassment 
isopleths.

                                  Table 5--User Spreadsheet Input Parameters Used for Calculating Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               12-in timber                                36-in and 42-in steel
                                                        ------------------------------------------------------------------------------------------------
                    Model parameter                                                                           Impact--with                     DTH--
                                                          Vibratory      Impact     Vibratory      Impact        bubble          DTH       simultaneous
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab........................................          A.1          E.1          A.1          E.1             E.1          E.1             E.1
Weighting Factor (kHz).................................          2.5            2          2.5          2.0             2.0          2.0             2.0
RMS (dB)...............................................          152          170          170          193             186          180             180
Peak/SEL (dB)..........................................           na      180/160           na      210/183         203/176      190/164         190/164
Number of piles/day *..................................            4            5            3            5               5            3               3
Duration to drive a pile (minutes).....................           30           na         12.0           na              na           na              na
Propagation............................................           15           15           15           15              15           15              15
Distance from source (meters)..........................           10           10           10           10              10           10              10
Strikes per pile.......................................           na         1000           na        1,000            1000       25,200          50,400
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Represents 50% of piles planned per day.


                                                   Table 6--Radial Distance to PTS Isopleths (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                     Hammer type                         Low-frequency       Mid-frequency      High-frequency     Phocid pinnipeds
-----------------------------------------------------      cetaceans           cetaceans           cetaceans     --------------------  Pile location in
                                                     ------------------------------------------------------------                      the PTST project
                                       Pile type      Island 1  Island 2  Island 1  Island 2  Island 1  Island 2  Island 1  Island 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact..........................  12-in. Timber.....        86        86         3         3       102       102        46        46  Mooring Dolphins.
Impact with Bubble Curtain......  36-in. Steel......     2,920     2,920       104       104     3,478     3,478     1,563     1,563  Omega Trestle,
                                                                                                                                       Temporary Dock,
                                                                                                                                       Berm Wall West,
                                                                                                                                       and Berm Wall
                                                                                                                                       East.
Impact with Bubble Curtain......  36-in. Steel......       997       997        36        36     1,188     1,188       534       534  Berm Wall West,
                                                                                                                                       Berm Wall East,
                                                                                                                                       and Temporary
                                                                                                                                       Dock.
DTH--Impulsive..................  36 and 42-in.            966       966        34        34     1,151     1,151       517       517  Casing for
                                   Steel.                                                                                              Temporary Dock.
DTH Simultaneous................                         1,534     1,534        55        55     1,827     1,827       821       821  Omega Trestle,
                                                                                                                                       Temporary Dock,
                                                                                                                                       Berm Wall West,
                                                                                                                                       and Berm Wall
                                                                                                                                       East.
DTH & Impact Hammer (Bubble       36-and 42-in.          1,963     1,963        70        70     2,399     2,399     1,051     1,051  Omega Trestle,
 Curtain) Simultaneous.            Steel.                                                                                              Temporary Dock,
                                                                                                                                       Berm Wall West,
                                                                                                                                       and Berm Wall
                                                                                                                                       East.
                                  12-in. Timber.....         3         3       0.2       0.2         4         4         2         2  Mooring Dolphins.
Continuous (Vibratory)..........  36-in. Steel......        19        19         2         2        29        29        12        12  Mooring Piles and
                                                                                                                                       Templates.
                                  42-in. Steel......        19  ........         2  ........        29  ........        12  ........  Casing for
                                                                                                                                       Temporary Dock.
--------------------------------------------------------------------------------------------------------------------------------------------------------


                  Table 7--Radial Distance (meters) to Level B Harassment Monitoring Isopleths
----------------------------------------------------------------------------------------------------------------
                                                                    Distance from
            Driving method                      Pile type           Island 1 & 2           Pile location
----------------------------------------------------------------------------------------------------------------
Impact................................  12-in. Timber............              22  Mooring Dolphins.
                                        36-in. Steel.............           1,585  Omega Trestle, Temporary
                                                                                    Dock, Berm Wall West, and
                                                                                    Berm Wall East.
Impact with Bubble Curtain............  36-in. Steel.............             541  Berm Wall West, Berm Wall
                                                                                    East, and Temporary Dock.
DTH--Impulsive........................  42-in. Steel.............           * 215  Casing for Temporary Dock.
                                        36-in. Steel.............             215  Omega Trestle, Temporary
                                                                                    Dock, Berm Wall West, and
                                                                                    Berm Wall East.
Continuous (Vibratory)................  12-in. mooring...........           1,359  Mooring Dolphins.
                                        36-in. Steel.............          21,544  Mooring Piles and Templates.
                                        42-in. Steel.............        * 21,544  Casing for Temporary Dock.
----------------------------------------------------------------------------------------------------------------
* Activity will not occur on Portal Island 2.


[[Page 16069]]

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 and describe how it is 
brought together with the information above to produce a quantitative 
take estimate. When available, peer-reviewed scientific publications 
were used to estimate marine mammal abundance in the project area. In 
some cases population estimates, densities, and other quantitative 
information are lacking. Local observational data and estimated group 
size were utilized where applicable.
Humpback Whale
    Humpback whales are relatively rare in the Chesapeake Bay and 
density data for this species within the project vicinity were not 
available nor able to be calculated. Populations in the mid-Atlantic 
have been estimated for humpback whales off the coast of New Jersey 
with a density of 0.000130 per square kilometer (Whitt et al. 2015). 
Habitat-based density models produced by the Duke University Marine 
Geospatial Ecology Laboratory (Roberts et al. 2016) represent the best 
available information regarding marine mammal densities offshore near 
the mouth of the Chesapeake Bay. At the closest point to the PTST 
project area, humpback densities ranged from a high of 0.107/100 km\2\ 
in March to 0.00010/100 km\2\ in August. Furthermore, the CTJV 
conducted marine mammal monitoring during SSV testing for 5 days in 
July 2019. During that time there were no sightings or takes of 
humpback whales.
    Because humpback whale occurrence is low as demonstrated above, the 
CTJV and NMFS estimated that there will be a single humpback sighting 
every two months for the duration of in-water pile driving activities. 
Only 10 months of in-water construction were anticipated when the 
proposed IHA was published, resulting in the proposed take of 10 
animals. A revised construction schedule has been developed by the CTJV 
and includes 11 months of planned in-water pile driving activity. Using 
an average group size of two animals, pile driving activities over an 
11-month period would result in 12 takes (rounding up) of humpback 
whale by Level B harassment. No takes by Level A harassment are 
expected or authorized.
Bottlenose Dolphin
    Expected bottlenose dolphin take was estimated using a 2016 report 
on the occurrence, distribution, and density of marine mammals near 
Naval Station Norfolk and Virginia Beach, Virginia (Engelhaupt et al. 
2016). Three years of dolphin survey data were collected from either 
in-shore or open ocean transects. In the proposed IHA, a subset of 
survey data from Engelhaupt et al. (2016) was used to determine 
seasonal dolphin densities in the Bay near the project area. A 
spatially refined approach was employed by plotting dolphin sightings 
within 12 km of the project location and then determining densities 
following methodology outlined in Engelhaupt et al. (2016) and Miller 
et al. (2019) using the package DISTANCE in R statistical software. The 
Commission believes that use of this truncated data was inappropriate 
since Engelhaupt et al. (2016) did not survey all of the area near the 
project site, but only surveyed within approximately 4 km of the coast. 
The Commission determined that this approach was flawed as it was not 
based on distance sampling methods and did not assume equal survey 
effort within the harassment zones, since the majority of the 
identified harassment zones had no survey effort. In response, NMFS 
indicated that it would use Engelhaupt et al. (2016) data to expand the 
truncated area using from 12 km to 19 km. The Commission felt that this 
was also inappropriate as monitoring data from the CTJV's site 
indicated that the densities provided by Engelhaupt et al. (2016) were 
closer to what was actually observed at the project area compared to 
the truncated Engelhaupt et al. (2016) data. The CTJV's sightings data 
from July 2019 recorded an average density of animals sighted of 4.37 
dolphins/km\2\. That density is actually greater than the original, 
untruncated Engelhaupt et al. (2016) density of 3.88 dolphins/km\2\ for 
summer. The observed 4.37 dolphins/km\2\ is much greater than the 
truncated estimate of 0.62 dolphins/km\2\ utilized in the notice of 
proposed IHA which was initially used to estimate take numbers. Given 
this information, it is likely that the number of takes estimated in 
the proposed IHA is far less than what is expected to be observed. 
Therefore, NMFS opted to use the original seasonal density values 
documented by Engelhaupt et al. (2016). These values were broken out by 
month as shown Table 9. The Level B harassment area for each pile and 
driving type as shown in Table 8 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 as shown in Table 9 (i.e. mooring 
cluster, temporary dock, omega trestle/west O-pile walls/mooring piles 
& templates, and omega trestle/east O-pile walls).

  Table 8--In-Water Area (km\2\) Used for Calculating Dolphin Takes per Construction Components per Hammer Type
----------------------------------------------------------------------------------------------------------------
                                                                     Vibratory     Impact + DTH      DTH + DTH
    Construction component          Pile type     Impact  hammer      hammer          hammers         hammers
----------------------------------------------------------------------------------------------------------------
Mooring Cluster...............  12-in Timber....           0.003            4.16              NA              NA
Temporary Dock................  36-in and 42-in           * 0.63             830            1.72            0.25
                                 Steel.
Omega Trestle and West O-pile   36-in and 42-in   ..............             830            1.72            0.49
 wall.                           Steel
East O-pile Wall..............  36-in and 42-in   ..............              NA            1.43            0.31
                                 Steel
----------------------------------------------------------------------------------------------------------------
* Impact Hammer with Bubble Curtain.


                                               Table 9--Estimated Takes of Bottlenose Dolphin by Level B Harassment by Month and Driving Activity
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                           Month
                                                                  ----------------------------------------------------------------------------------------------------------------------
                                                                    March    April    May    June     July    August   September   October   November    December    January   February
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Dolphin Density (n/km\2\)........................................        1       1       1    3.55     3.55     3.55        3.88      3.88        3.88        0.63      0.63       0.63  .......
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Days/Month based on Pile Driving Activity
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 16070]]

 
                                                                                         Mooring Cluster
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory--Timber Piles..........................................        0       0       1       1        0        0           0         0           0           0         0          0  .......
Impact--Timber Piles.............................................        0       0       2       7        6        5           5         0           0           0         0          0
Dolphin Takes....................................................      0.0     0.0     4.2    14.8      0.1      0.1         0.1       0.0         0.0         0.0       0.0        0.0       19
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Temporary Dock
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
DTH+ Impact--Steel Pile..........................................        4      11      11       4        0        0           0         0           0           0         0          0  .......
Vibratory--Steel Pile............................................        2       3       3       2        0        0           0         0           0           0         0          0
Two DTH--Steel Pile..............................................        0       0       0       0        0        0           0         0           0           0         0          0
Dolphin Takes....................................................    1,667   2,509   2,509   5,917        0        0           0         0           0           0         0          0   12,602
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Omega Trestle/West O-pile Walls/Mooring Piles & Templates
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory--Steel Pile............................................        0       0       0       1        1        0           2         1           0           0         0          0  .......
Two DTH--Steel Pile..............................................        1       2       2       2        2        2           2         5           0           0         0          0
DTH+ Impact--Steel Pile..........................................        4       2       5       5        5        8           5         5           5           5         2          0
Dolphin Takes....................................................        7       4      10   2,981    2,981     52.4     6,478.0   3,263.3        33.4         5.4       2.2        0.0   15,817
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Omega Trestle/East O-Pile Walls
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
DTH+ Impact--Steel Pile..........................................        0       2       2       7        8        8           8         5           5           5         2          0  .......
Two DTH--Steel Pile..............................................        0       0       0       0        2        0           1         1           1           0         0          0
Dolphin Takes....................................................        0       3       3      36       43       41          46        29          29           5         2          0      235
Total No. of Pile Driving Days per Month.........................       11      20      26      29       24       23          23        17          11          10         4          0
                                                                  ------------------------------------------------------------------------------------------------------------------------------
    Total Takes..................................................  .......  ......  ......  ......  .......  .......  ..........  ........  ..........  ..........  ........  .........   28,674
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    The number of calculated takes for each of the four project 
components identified in Table 9 resulted in a total of 28,674 
authorized takes. The authorized takes were split out among the three 
dolphin stocks as shown in Table 10. There is insufficient information 
to apportion the takes precisely to the three stocks present in the 
area. Given that most of the NNCES stock are found in the Pamlico Sound 
estuarine system, NMFS will assume that no more than 200 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 size 
of that population is unknown.
    Since the largest Level A harassment isopleth is 104 m and there is 
a shutdown zone of 100 m, NMFS will assume that 1 percent of each 
designated stock will occur between 100 and 104 meters or will appear 
in the PTS zone without first being observed by PSOs resulting in the 
number of dolphin takes by Level A harassment shown in Table 10. NMFS 
had not proposed take by Level A harassment in the notice of proposed 
IHA. However, the Level A harassment isopleth for impact driving of 36-
in steel piles exceeds the 100-m shutdown zone and the number of 
authorized takes has increased.
Harbor Porpoise
    Given that harbor porpoises are uncommon in the project area, this 
exposure analysis assumes that there is a porpoise sighting once during 
every two months of operations which would equate to six sightings 
(rounding up) over 11 months. Assuming an average group size of two 
(Hansen et al. 2018; Elliser et al. 2018) over 11 months of in-water 
work results in a total of 12 estimated takes of porpoises. (In the 
proposed IHA, NMFS had assumed 10 months of driving resulting in 10 
total takes.) Harbor porpoises are members of the high-frequency 
hearing group which have Level A harassment isopleths as large as 3,478 
m during impact installation of 10 36-in steel piles per day. Given the 
relatively large Level A harassment zones during impact driving, NMFS 
assumed in the previous IHA (83 FR 36522; July 30, 2018) that 40 
percent of estimated porpoises takes would be by Level A harassment. 
NMFS assumed the same ratio for the issued IHA resulting in five 
authorized takes of porpoises by Level A harassment and seven takes by 
Level B harassment. When the CTJV conducted marine mammal monitoring 
during SSV testing at the project location for 5 days in July 2019, 
there were no sightings of porpoises.
Harbor Seal
    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 United States Navy at the portal islands 
from November 2014 through April 2018 (Rees et al., 2016; Jones et al. 
2018). The survey data revealed a daily maximum of 45 animals during 
this period which occurred in January, 2018. The maximum number of 
animals observed per day (45) was multiplied by the total number of 
planned driving days between November and May (72) since seals are not 
present in the area from June through October. In the proposed IHA, 
NMFS had assumed 173 days of driving during this same period. Based on 
this revised calculation NMFS has authorized 3,240 incidental takes of 
harbor seal for this IHA. Note that the CTJV monitoring report did not 
record any seal observations over 5 days of SSV testing, but this would 
be expected as seals are not present during July.

[[Page 16071]]

    The largest Level A harassment isopleth for phocid species is 
approximately 1,563 meters which would occur during impact driving of 
36-inch steel piles. The smallest Level A harassment isopleths are 2 m 
and would occur during impact and vibratory driving of 12-inch timber 
piles. NMFS has prescribed a shutdown zone for harbor seals of 15 
meters as a mitigation measure since seals are common in the project 
area and are known to approach the shoreline. A larger shutdown zone 
would likely result in multiple shutdowns and impede the project 
schedule. From the previously issued IHA, NMFS assumed that 40 percent 
of the exposed seals will occur within the Level A harassment zone 
specified for a given scenario and the remaining affected seals would 
result in Level B harassment takes. Therefore, NMFS has authorized 
1,296 takes by Level A harassment and 2,124 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 time 
during 2017 or 2018. As part of the proposed IHA, NMFS anticipated gray 
seals would occur only during the 21 planned work days for February at 
a rate of one animal per day. Due to revisions to the construction 
schedule, no in-water pile driving is scheduled to occur in February 
under the effective period for this IHA. However, there could be delays 
to the construction schedule resulting in the need for in-water work in 
February 2021. To reduce the possibility that non-authorized take of 
gray seal could result in work stoppage, NMFS has conservatively 
authorized take of four gray seals, one by Level A harassment and three 
by Level B harassment.
    Table 10 shows authorized take numbers for Level A and Level B 
harassment.

                           Table 10--Authorized Take by Level A and Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                                                                   Percentage of
                Species                           Stock            Level A takes   Level B takes       stock
----------------------------------------------------------------------------------------------------------------
Humpback whale........................  Gulf of Maine...........  ..............              12             0.8
Harbor porpoise.......................  Gulf of Maine/Bay of                   5               7           <0.01
                                         Fundy.
Bottlenose dolphin....................  WNA Coastal, Northern                142          14,095         \*\ <33
                                         Migratory.
                                        WNA Coastal, Southern                142          14,095         \*\ <33
                                         Migratory.
                                        NNCES...................               2             198              24
Harbor seal...........................  Western North Atlantic..           1,296           2,124             4.5
Gray seal.............................  Western North Atlantic..               1               3           <0.01
----------------------------------------------------------------------------------------------------------------
* Assumes multiple repeated takes of same individuals from small portion of each stock as well as repeated takes
  of Chesapeake Bay resident population (size unknown).

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 such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such 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 such 
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.
    In addition to the measures described later in this section, the 
CTJV will employ the following standard mitigation measures:
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water heavy machinery work other than pile driving 
(e.g., standard barges, etc.), if a marine mammal comes within 10 m, 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions. This 
type of work could include the following activities: (1) Movement of 
the barge to the pile location; or (2) positioning of the pile on the 
substrate via a crane (i.e., stabbing the pile);
     Work may only occur during daylight hours, when visual 
monitoring of marine mammals can be conducted;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile driving will shut down 
immediately if such species are observed within or entering the 
monitoring zone (i.e., Level B harassment zone); and
     If take reaches the authorized limit for an authorized 
species, pile installation will be stopped as these species approach 
the Level B harassment zone to avoid additional take.
    The following measures will apply to the CTJV's mitigation 
requirements:
    Establishment of Shutdown Zone--For all pile driving and drilling

[[Page 16072]]

activities, the CTJV will establish a shutdown zone. The purpose of a 
shutdown zone is generally to define an area within which shutdown of 
activity will occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). These shutdown 
zones will be used to reduce incidental Level A harassment from impact 
pile driving for bottlenose dolphins and harbor porpoises. Shutdown 
zones for species authorized for take are as follows:
     100 meters for harbor porpoise and bottlenose dolphin.
     15 meters for harbor seal and gray seal.
     For humpback whale, shutdown distances are shown in Table 
14 under low-frequency cetaceans and are dependent on activity type.
    Establishment of Monitoring Zones for Level A and Level B 
Harassment--The CTJV will establish monitoring zones based on 
calculated Level A harassment isopleths associated with specific pile 
driving activities and scenarios. These are areas beyond the 
established shutdown zone in which animals could be exposed to sound 
levels that could result in Level A harassment in the form of PTS. The 
CTJV will also establish and monitor Level B harassment zones which are 
areas where SPLs are equal to or exceed the 160 dB rms threshold for 
impact driving and DTH drilling and 120 dB rms threshold during 
vibratory driving. Monitoring zones provide utility for observing by 
establishing monitoring protocols for areas adjacent to the shutdown 
zones. The monitoring zones enable observers to be aware of and 
communicate the presence of marine mammals in the project area outside 
the shutdown zone and thus prepare for a potential cease of activity 
should the animal enter the shutdown zone. The Level A and Level B 
harassment monitoring zones are described in Table 11. Since some of 
the Level A and Level B harassment monitoring zones cannot be 
effectively observed in their entirety, exposures will be recorded and 
extrapolated based upon the number of observed take and the percentage 
of the Level A and Level B harassment zone that was not visible.

                              Table 11--Level A and Level B Harassment Monitoring Zones During Project Activities (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                              Scenario                                                    Level A harassment zones                           Level B
----------------------------------------------------------------------------------------------------------------------------------------    monitoring
                                                                      Low-frequency    Mid-frequency    High-frequency       Phocid           zones
                                                                        cetaceans        cetaceans        cetaceans        pinnipeds    ----------------
              Driving type                        Pile type         --------------------------------------------------------------------
                                                                      Island 1  & 2    Island 1  & 2    Island 1  & 2    Island 1  & 2     Island 1 & 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact.................................  12-in. Timber.............               90               --              105               --              25.
                                         36-in. Steel..............            2,920              105            3,480            1,565           1,585.
Impact with Bubble Curtain.............  36-in. Steel..............            1,000               --            1,190              535             545.
DTH--Impulsive.........................  42-in. Steel..............              970               --            1,155              520             215.
DTH Simultaneous at same island........  42-in. Steel..............            1,535               --            1,830              825             215.
DTH & Impact Hammer with bubble          36-and 42-in. Steel.......            1,970               --            2,400            1,055             545.
 curtain: Simultaneous at the same
 island.
DTH at PI 1. And Impact with Bubble      36-and 42-in. Steel.......              970               --            1,155              520   215 from PI 1.
 Curtain Hammer at PI 2.                                                                                                                  545 from PI 2.
Continuous (Vibratory).................  12-in. Timber.............               --               --               --               --           1,360.
                                         36-in. Steel..............               20               --               --               --          21,545.
                                         42-in.** Steel............               20               --               --               --          21,545.
--------------------------------------------------------------------------------------------------------------------------------------------------------
-- indicates that shutdown zone is larger than calculated harassment zone.
** Activity only planned at Portal Island 1 as part of project pile driving plan.

    Soft Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
will be required to provide an initial set of strikes from the hammer 
at reduced energy, with each strike followed by a 30-second waiting 
period. This procedure will be conducted a total of three times before 
impact pile driving begins. Soft start will be implemented at the start 
of each day's impact pile driving and at any time following cessation 
of impact pile driving for a period of 30 minutes or longer. Soft start 
is not required during vibratory or DTH pile driving activities.
    Use of Bubble Curtains--Use of air bubble curtain system will be 
implemented by the CTJV during impact driving of 36-in steel piles 
except in water less than 10 ft in depth. The use of this sound 
attenuation device will reduce SPLs and the size of the zones of 
influence for Level A harassment and Level B harassment. Bubble 
curtains will meet the following requirements:
     The bubble curtain must distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column.
     The lowest bubble ring shall be in contact with the 
mudline and/or rock bottom for the full circumference of the ring, and 
the weights attached to the bottom ring shall ensure 100 percent 
mudline and/or rock bottom contact. No parts of the ring or other 
objects shall prevent full mudline and/or rock bottom contact.
     The bubble curtain shall be operated such that there is 
proper (equal) balancing of air flow to all bubblers.
     The applicant shall require that construction contractors 
train personnel in the proper balancing of air flow to the bubblers and 
corrections to the attenuation device to meet the performance 
standards. This shall occur prior to the initiation of pile driving 
activities.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving of 30 
minutes or longer occurs, PSOs will observe the shutdown and monitoring 
zones for a period of 30 minutes. The shutdown zone will be cleared 
when a marine mammal has not been observed within the zone for that 30-
minute period. If a marine mammal

[[Page 16073]]

is observed within the shutdown zone, a soft-start cannot proceed until 
the animal has left the zone or has not been observed for 15 minutes. 
If the Level B harassment zone has been observed for 30 minutes and 
non-permitted species are not present within the zone, soft start 
procedures can commence and work can continue even if visibility 
becomes impaired within the Level B harassment monitoring zone. When a 
marine mammal permitted for take by Level B harassment is present in 
the Level B harassment zone, activities may begin and Level B 
harassment take will be recorded. If work ceases for more than 30 
minutes, the pre-activity monitoring of both the Level B harassment and 
shutdown zone will commence again. Additionally, in-water construction 
activity must be delayed or cease, if poor environmental conditions 
restrict full visibility of the shut-down zone(s) until the entire 
shut-down zone(s) is visible.
    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the required 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 
planned 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).
     Mitigation and monitoring effectiveness.

Marine Mammal Visual Monitoring

    Monitoring shall be conducted by NMFS-approved observers. Trained 
observers shall be placed from the best vantage point(s) practicable to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable through communication with the equipment operator. 
Observer training must be provided prior to project start, and shall 
include instruction on species identification (sufficient to 
distinguish the species in the project area), description and 
categorization of observed behaviors and interpretation of behaviors 
that may be construed as being reactions to the specified activity, 
proper completion of data forms, and other basic components of 
biological monitoring, including tracking of observed animals or groups 
of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile driving activities. In addition, observers shall 
record all incidents of marine mammal occurrence, regardless of 
distance from activity, and shall document any behavioral reactions in 
concert with distance from piles being driven. Pile driving activities 
include the time to install a single pile or series of piles, as long 
as the time elapsed between uses of the pile driving equipment is no 
more than 30 minutes. The CTJV will be required to station between two 
and four PSOs at locations offering the best available views of the 
monitoring zones. At least two PSOs will be required to monitor before, 
during, and after the pile-driving and -removal activities. At least 
one PSO must be located in close proximity to each pile driving rig 
during active operation of single or multiple, concurrent driving 
devices. At least one additional PSO is required at each active driving 
rig or other location providing best possible view if the Level B 
harassment zone and shutdown zones cannot reasonably be observed by one 
PSO.
    PSOs will scan the waters using binoculars, and/or spotting scopes, 
and will use a handheld GPS or range-finder device to verify the 
distance to each sighting from the project site. All PSOs will be 
trained in marine mammal identification and behaviors and are required 
to have no other project-related tasks while conducting monitoring. In 
addition, monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. The CTJV will 
adhere to the following PSO qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required.
    (ii) At least one observer must have prior experience working as an 
observer.
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience.
    (iv) Where a team of three or more observers are required, one 
observer shall be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer.
    (v) The CTJV shall submit observer CVs for approval by NMFS. 
Additional standard observer qualifications include:
     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 and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals

[[Page 16074]]

observed within a defined shutdown zone; 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.
    Observers will be required to use approved data forms. Among other 
pieces of information, The CTJV will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the CTJV will attempt to 
distinguish between the number of individual animals taken and the 
number of incidences of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity, and if possible, the correlation to SPLs;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Description of implementation of mitigation measures 
(e.g., shutdown or delay);
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    A draft report will be submitted to NMFS within 90 days of the 
completion of marine mammal monitoring, or 60 days prior to the 
requested date of issuance of any future IHA for projects at the same 
location, whichever comes first. The report will include marine mammal 
observations pre-activity, during-activity, and post-activity during 
pile driving days (and associated PSO data sheets), and will also 
provide descriptions of any behavioral responses to construction 
activities by marine mammals and a complete description of all 
mitigation shutdowns and the results of those actions and an 
extrapolated total take estimate based on the number of marine mammals 
observed during the course of construction. A final report must be 
submitted within 30 days following resolution of comments on the draft 
report.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the CTJV shall report the 
incident to the Office of Protected Resources (OPR), NMFS and to the 
Greater Atlantic Region New England/Mid-Atlantic Regional Stranding 
Coordinator as soon as feasible. 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 activities associated with the planned PTST project, 
as outlined previously, have the potential to disturb or displace 
marine mammals. The specified activities may result in take, in the 
form of Level B harassment (behavioral disturbance) or Level A 
harassment (auditory injury), incidental to underwater sounds generated 
from pile driving. Potential takes could occur if individuals are 
present in the ensonified zone when pile driving occurs. Level A 
harassment is anticipated for bottlenose dolphins, harbor porpoises, 
harbor seals, and gray seals.
    No serious injury or mortality is anticipated given the nature of 
the activities and measures designed to minimize the possibility of 
injury to marine mammals. The potential for these outcomes is minimized 
through the construction method and the implementation of the planned 
mitigation measures. Specifically, vibratory driving, impact driving, 
and drilling with DTH hammers will be the primary methods of 
installation and pile removal will occur with a vibratory hammer. 
Impact pile driving produces short, sharp pulses with higher peak 
levels and much sharper rise time to reach those peaks. When impact 
pile driving is used, implementation of bubble curtains, soft start and 
shutdown zones significantly reduces any possibility of injury. Given 
sufficient notice through use of soft starts (for impact driving), 
marine mammals are expected to move away from a sound source that is 
annoying prior to it becoming potentially injurious.
    The CTJV will use qualified PSOs stationed strategically to 
increase detectability of marine mammals, enabling a high rate of 
success in implementation of shutdowns to avoid injury for most 
species. PSOs will be stationed on a specific Portal Island whenever 
pile driving operations are underway at that location. Additional PSOs 
will be stationed at the same Portal Island and in other locations in 
order to provide a relatively clear views of the shutdown zone and 
monitoring zones. These factors will limit exposure of animals to noise 
levels that could result in injury.
    The CTJV's planned pile driving activities are highly localized. 
Only a relatively small portion of the Chesapeake Bay may be affected. 
Localized noise exposures produced by project activities may cause 
short-term

[[Page 16075]]

behavioral modifications in affected cetaceans and pinnipeds Moreover, 
the required mitigation and monitoring measures are expected to further 
reduce the likelihood of injury as well as reduce behavioral 
disturbances.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006). Individual animals, even if taken multiple times, will most 
likely move away from the sound source and be temporarily displaced 
from the areas of pile driving, although even this reaction has been 
observed primarily only in association with impact pile driving. The 
pile driving activities analyzed here are similar to, or less impactful 
than, numerous other construction activities conducted along both 
Atlantic and Pacific coasts, which have taken place with no known long-
term adverse consequences from behavioral harassment. Furthermore, many 
projects similar to this one are also believed to result in multiple 
takes of individual animals without any documented long-term adverse 
effects. Level B harassment will be minimized through use of mitigation 
measures described herein and, if sound produced by project activities 
is sufficiently disturbing, animals are likely to simply avoid the area 
while the activity is occurring.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that small numbers of dolphins, harbor 
porpoises, harbor seals and gray seals may sustain some limited Level A 
harassment in the form of auditory injury. However, animals that 
experience PTS would likely only receive slight PTS, i.e. minor 
degradation of hearing capabilities within regions of hearing that 
align most completely with the energy produced by pile driving (i.e., 
the low-frequency region below 2 kHz), not severe hearing impairment or 
impairment in the regions of greatest hearing sensitivity. If hearing 
impairment occurs, it is most likely that the affected animal's 
threshold would increase by a few dBs, which is not likely to 
meaningfully affect its ability to forage and communicate with 
conspecifics. As described above, we expect that marine mammals would 
be likely to move away from a sound source that represents an aversive 
stimulus, especially at levels that would be expected to result in PTS, 
given sufficient notice through use of soft start.
    The project is not expected to have significant adverse effects on 
marine mammal habitat. No important feeding and/or reproductive areas 
for marine mammals are known to be near the project area. Project 
activities would not permanently modify existing marine mammal habitat. 
The activities may cause some fish to leave the area of disturbance, 
thus temporarily impacting marine mammal foraging opportunities in a 
limited portion of the foraging range. However, because of the 
relatively small area of the habitat that may be affected, the impacts 
to marine mammal habitat are not expected to cause significant or long-
term negative consequences.
    In summary and as described above, the following factors primarily 
support our preliminary 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;
     Limited Level A harassment exposures (dolphins, harbor 
porpoises, harbor seals, and gray seals) are anticipated to result only 
in slight PTS, within the lower frequencies associated with pile 
driving;
     The anticipated incidents of Level B harassment consist 
of, at worst, temporary modifications in behavior that would not result 
in fitness impacts to individuals;
     The specified activity and associated ensonifed areas are 
very small relative to the overall habitat ranges of all species and 
does not include habitat areas of special significance (BIAs or ESA-
designated critical habitat); and
     The presumed efficacy of the required mitigation measures 
in reducing the effects of the specified activity.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the planned 
activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    Authorized take of marine mammal stocks comprises less than 5 
percent of the Western North Atlantic harbor seal stock abundance, and 
less than one percent of all other authorized stocks, with the 
exception of bottlenose dolphins. There are three bottlenose dolphin 
stocks that could occur in the project area. Therefore, the estimated 
28,674 dolphin takes by Level A and 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 200 takes from the 
NNCES stock, representing 24 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 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

[[Page 16076]]

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 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 (~two 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 (<=1km 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 
(Patterson, Pers. Comm).
    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, pers. comm.). 
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.
    In summary and as described above, the following factors primarily 
support our preliminary 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 5 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; 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 planned activity 
(including the required mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks 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 action (i.e., the issuance of incidental 
harassment authorizations) with respect to potential impacts on the 
human environment. This action is consistent with categories of 
activities identified in Categorical Exclusion B4 (incidental 
harassment authorizations 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 this IHA to the CTJV qualifies to be categorically 
excluded from further NEPA review.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat.
    No incidental take of ESA-listed species is authorized 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 incidental take of 
marine mammal due to pile driving activities as part of the PTST 
project for a period of one year from the date of issuance, provided 
the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.


[[Page 16077]]


    Dated: March 10, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-05802 Filed 3-19-20; 8:45 am]
 BILLING CODE 3510-22-P