[Federal Register Volume 83, Number 146 (Monday, July 30, 2018)]
[Notices]
[Pages 36522-36538]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-16204]



[[Page 36522]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG107


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.

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

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 
Chesapeake Tunnel Joint Venture (CTJV) to incidentally take, by Level A 
and/or Level B harassment, four species of marine mammals during the 
Parallel Thimble Shoal Tunnel Project (PTST) in Virginia Beach, 
Virginia.

DATES: This Authorization is effective from August 1, 2018, through 
July 31, 2019.

FOR FURTHER INFORMATION CONTACT: Rob 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    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 United States citizens who engage in a specified 
activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, 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).

Summary of Request

    On January 11, 2018, NMFS received a request from the CTJV for an 
IHA to take marine mammals incidental to pile driving at the Chesapeake 
Bay Bridge and Tunnel (CBBT) near Virginia Beach, Virginia. CTJV's 
request is for take of small numbers of harbor seal (Phoca vitulina), 
gray seal (Halichoerus grypus), bottlenose dolphin (Tursiops spp.), 
harbor porpoise (Phocoena phocoena), and humpback whale (Megaptera 
novaeangliae) by Level A and Level B harassment. Neither the CTJV nor 
NMFS expect serious injury or mortality to result from this activity 
and, therefore, an IHA is appropriate.
    NMFS has issued an IHA to CTJV authorizing the take of five species 
by Level A and Level B harassment. Pile driving and removal will take 
up to 202 days. The IHA is effective from August 1, 2018 through July 
31, 2019.

Description of Planned Activity

    The PTST 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 (Figure 1 in application). 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 
Chesapeake Bay Bridge-Tunnel (CBBT) facility; improve safety by 
minimizing one lane, two-way traffic in the tunnel; improve the ability 
to conduct necessary maintenance with minimal impact to traffic flow; 
and ensure a reliable southwest hurricane evacuation route for 
residents of the eastern shore and/or a northern evacuation route for 
residents of the eastern shore, Norfolk, and Virginia Beach. The CBBT 
is a 23 mile fixed link crossing the mouth of the Chesapeake Bay which 
connects Northampton County on the Delmarva Peninsula with Virginia 
Beach, which is part of the Hampton Roads metropolitan area.
    The new parallel tunnel will be bored under the Thimble Shoal 
Channel. The 6,525 linear feet (ft) of new tunnel will be constructed 
with a top of tunnel depth/elevation of 100 ft below Mean Low Water 
(MLW) within the width of the 1,000-ft-wide navigation channel. Impact 
pile driving will be used to install steel piles and vibratory pile 
driving will be utilized to install sheet piles. This issued IHA would 
cover one year of a larger project for which will run through 2022. The 
larger project, which does not employ pile driving and does not require 
additional IHAs, involves tunnel excavation with a tunnel boring 
machine and construction of a roadway within the tunnel. The type and 
numbers of piles to be installed, as well as those that will be removed 
during the effective period are summarized in Table 1.

                                 Table 1--Anticipated Pile Installation Schedule
----------------------------------------------------------------------------------------------------------------
                                                                                Number of
          Pile location               Pile function          Pile type       piles (upland/      Anticipated
                                                                                In-water)     installation date
----------------------------------------------------------------------------------------------------------------
Portal Island Nos. 1 and 2.......  Mooring dolphins     36-inch diameter                 30  15 July to 15
                                    (in-water).          hollow steel.                        August 2018.

[[Page 36523]]

 
West of Portal Island No. 1......  Berm construction    36-inch diameter                 80  15 July 2018
                                    trestle (in-water).  hollow steel.                        through 1 January
                                                                                              2019.
West of Portal Island No. 2......  Berm construction    36-inch diameter                 80  15 July 2018
                                    trestle (in-water).  hollow steel.                        through 1 January
                                                                                              2019.
Portal Island No. 1..............  Temporary docks      36-inch diameter                 50  1 May 2018 through
                                    (upland).            hollow steel.                        30 June 2018.
Portal Island No. 1..............  Temporary docks (in- 36-inch diameter                 82  15 July 2018 to 30
                                     water).             hollow steel.                        August 2018.
Portal Island No. 2 (above MHW)..  Temporary roadway    36-inch diameter                 12  1 May to 31 May
                                    trestle (upland).    hollow steel.                        2018.
Portal Island No. 1 (above MHW)..  Excavated TBM        28 and 18-inch                1,110  1 May 2018 to 30
                                    material             steel sheet.                         September 2018.
                                    containment
                                    holding (muck) bin
                                    (upland).
Portal Island Nos. 1 and 2 (above  Settlement           28-inch steel sheet           2,554  1 August 2018 to 30
 and below MHW).                    mitigation and                                            March 2019.
                                    flowable fill
                                    containment.
Portal Island Nos. 1 and 2 (above  Portal excavation..  Steel sheet........           1,401  1 June 2018 to 30
 MHW).                                                                                        September 2018, 1
                                                                                              January to 30
                                                                                              March 2019.
Portal Island Nos. 1 and 2 (above  Excavation Support.  Steel sheet........             240  1 April 2018 to 30
 MHW).                                                                                        August 2019 to 1
                                                                                              January 2019 to 30
                                                                                              March 2019.
    Total (above and below water)  ...................  ...................     5,305 Sheet  ...................
                                                                                  Piles 334
                                                                                Round Piles
----------------------------------------------------------------------------------------------------------------

    CTJV will install up to 272 in-water 36-in steel pipe piles by 
impact driving and 1,936 in-water sheet piles by vibratory installation 
and expects activities to take up to 202 days. These actions could 
produce underwater sound at levels that could result in the injury or 
behavioral harassment of marine mammal species. A detailed description 
of CTJV's planned project is provided in the Federal Register notice 
for the proposed IHA (83 FR 18777; April 30, 2018). Since that time, 
the project start date has been delayed by approximately one month. No 
additional changes have been made to the planned project activities. 
Therefore, a detailed description is not provided here. Please refer to 
that Federal Register notice for the description of the specific 
activity.

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to CTJV was published 
in the Federal Register on April 30, 2018 (83 FR 18777). That notice 
described, in detail, CTJV's 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 one 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 recommended that NMFS review more 
thoroughly both the applications prior to deeming them complete and its 
notices prior to submitting them for publication in the Federal 
Register and that NMFS better evaluate the proposed exclusion/shut-down 
zones that are to be implemented for each proposed incidental take 
authorization. Further, the Commission references several specific 
minor errors that were in the proposed notice (for example, incorrect 
numbers in Tables).
    Response: NMFS thanks the Commission for its recommendation. NMFS 
makes every effort to read the notices thoroughly prior to publication 
and will continue this effort to publish the best possible product for 
public comment. NMFS will be diligent when considering the 
appropriateness of proposed exclusion and shutdown zones for future 
IHAs. Further, NMFS has corrected the errors the Commission noted.
    Comment 2: The Commission noted that NMFS used the lower reported 
source level for estimating the various Level A and B harassment zones 
during vibratory pile driving, which resulted in underestimating the 
Level A and B harassment zones, associated ensonified areas, and number 
of takes of bottlenose dolphins.
    Response: Note that in the Federal Register notice of proposed IHA 
(83 FR 18777; April 30, 2018) a source value of 154 dB RMS SPL was 
applied for vibratory installation of 28-inch sheet. NMFS used a higher 
source level of 155 dB RMS SPL in this notice. The vibratory source 
levels based on root-mean-square sound pressure levels (SPLrms) and 
sound exposure levels metrics were not the same value according to 
NAVFAC 2017 which was cited as the reference for these values. 
Furthermore, the source levels based on 1-sec averages (155 dB RMS SPL) 
and 10-sec averages (154 dB RMS SPL) were not identical when they 
should be represented by the same value. When a difference is reported, 
it likely is due to the operator averaging decibels rather than taking 
the linear average of the pressures/intensities and then converting to 
dB. Therefore, the higher source level (155 dB RMS SPL) has been 
adopted in this notice.
    Comment 3: The Commission noted that NMFS used incorrect 
assumptions for estimating the various Level A and B harassment zones 
when multiple hammers are used.
    Response: NMFS used a source value of 186 dB RMS SPL to estimate 
the extent of the Level A harassment zone during simultaneous impact 
driving of two piles. NMFS incorrectly added 3 dB to the source levels 
after employing the rules for decibal addition as described in WSDOT 
2017. However, the rules of decibal addition do not apply to 
simultaneous impact driving scenarios since hammer strikes will not be 
synchronized. Therefore, NMFS has reverted to using the original proxy 
source level of 183 dB when estimating the extent of the Level A 
harassment zone during simultaneous impact

[[Page 36524]]

driving of two piles with bubble curtains.
    Comment 4: The Commission commented that NMFS did not not account 
for the possibility that the proposed in-water activities would not be 
finished by March 31 which is the deadline established by CTJV. 
Therefore, the numbers of harbor seal Level A and B harassment takes is 
underestimated.
    Response: Even with the delay in project schedule, CTJV is 
confident that in-water activities will be concluded by March 31, 2019. 
To minimize the risk that the number of harbor seal takes may be 
exceeded, for this notice NMFS used the maximum haul-out count from on-
site surveys (40) multiplied by the number of days of proposed 
activities (202) to estimate the number of harbor seal takes. In the 
Federal Register notice of proposed IHA (83 FR 18777; April 30, 2018), 
NMFS had multiplied monthly sighting rates by months of activities with 
an end date of March 31.
    Comment 5: The Commission noted NMFS used inconsistent assumptions 
regarding estimating Level A harassment takes. NMFS assumed that 40 
percent of the total number of harbor porpoise takes would equate to 
total Level A harassment takes based on the large size of the Level A 
harassment zones. However, NMFS did not make this assumption when 
estimated Level A jarassment take of harbor and gray seals.
    Response: In this notice, NMFS has assumed that Level A harassment 
takes of harbor seals and gray seals represent 40 percent of total 
takes for each species.
    Comment 6: The Commission noted that NMFS was requiring two 
protected species observers (PSOs) only during simultaneous pile 
driving. The Commission felt that two PSOs should be employed during 
all pile driving activities.
    Response: NMFS had proposed that only a single PSO would be 
required during non-simultaneous pile driving. The PSO would be 
stationed on the portal island where non-simultaneous pile driving was 
underway. However, given the large sizes of the monitoring zones, NMFS 
will require two PSO's during all pile driving operations to ensure 
adequate visual coverage of the monitoring zones.
    Comment 7: The Commission felt that the proposed 50-m exclusion 
zone for phocids was unnecessarily large for vibratory pile driving 
which could put CTJV in a situation in which it is implementing 
numerous unnecessary delays or shut downs for pinnipeds.
    Response: NMFS agrees with this assessment and has reduced the size 
of the exclusion zone for phocids from 50 m to 15 m during vibratory 
pile driving.
    Comment 8: The Commission feels there are some shortcomings that 
need to be addressed regarding the methodology for determining the 
extent of the Level A harassment zones based on the associated PTS 
cumulative sound exposure level (SELcum) thresholds for the 
various types of sound sources. Specifically, the Commission believes 
that the Level A and B harassment zones do not make sense biologically 
or acoustically in the context of one another (when the Level A 
harassment zone is larger than the Level B harassment zone) due to 
NMFS's unrealistic assumption that the animals remain stationary 
throughout the entire day of the activity. The Commission believes that 
it would be prudent for NMFS to consult with scientists and 
acousticians to determine the appropriate accumulation time that action 
proponents should use to determine the extent of the Level A harassment 
zones based on the associated PTS SELcum thresholds in such 
situations.
    Response: During the 2016 Technical Guidance's recent review, in 
accordance with E.O. 13795, NMFS received comments from multiple 
Federal agencies, including the Commission, recommending the 
establishment of a working group to investigate more realistic means of 
approximating the accumulation period associated with sound exposure 
beyond the default 24-h accumulation period. Based on these comments, 
NMFS will be convening a working group to re-evaluate implementation of 
the default 24-h accumulation period and investigate means for deriving 
more realistic accumulation periods. Nonetheless, although NMFS Level A 
harassment zones include conservative assumptions and may overestimate 
the likelihood of injury somewhat, the take estimates are appropriate 
given the available information and support a robust negligible impact 
analysis and support the small numbers finding.
    Comment 9: The Commission noted that NMFS has been inconsistently 
applying presumed source level reductions when bubble curtains are used 
during impact pile driving. The Commission recommended that NMFS 
refrain from using a source level reduction factor for sound 
attenuation device implementation (i.e., bubble curtains) during impact 
pile driving for all relevant incidental take authorizations. If and 
when NMFS determines the appropriate accumulation time associated with 
its SELcum thresholds, it could consider using a source level reduction 
to estimate the ranges to Level A harassment. NMFS should then review 
the related literature on bubble curtain efficacy in concert with 
estimated ranges to the SELcum thresholds based on the 
revised accumulation time to determine what, if any, source level 
reduction would be appropriate. The Commission further recommended that 
NMFS refrain from using a source level reduction factor for sound 
attenuation device implementation during impact pile driving for all 
relevant incidental take authorizations and that source levels should 
not be reduced when determining the range to Level B harassment.
    Response: NMFS believes it reasonable to use a source level 
reduction factor for sound attenuation device implementation during 
impact pile driving. NMFS understands that previous study results have 
been inconsistent and that noise level reductions measured at different 
received ranges may vary, given that both Level A and Level B 
estimation using geometric modeling is based on noise levels measured 
at near-source distances (~10 m). NMFS is working on guidance to 
increase consistency in the application of source level deductions from 
bubble curtain use, but in the meanwhile continues to evaluate 
proposals on a case by case basis. In this case we used a 10-dB 
reduction factor based on data from Caltrans 2015. We understand that 
there are other reported reduction levels that also could have been 
selected. However, we were unable to identify studies of bubble curtain 
efficacy that would have been any more applicable to the CTJV project 
than Caltrans 2015.
    The Commission is opposed to the use of noise reduction factors 
during impact driving as well as application of reductions to Level B 
harassment. The Commission feels that bubble curtains have not 
consistently achieved reduced sound levels in the far field because 
sound resonates through the ground into the far field. Bubble curtains 
are not designed to, nor can they, attenuate ground-borne sound. While 
NMFS agrees that some energy is transmitted through the ground into the 
farfield, it is also likely that most of the energy is transmitted 
through the water column. Given that most studies of bubble curtain 
effectiveness have demonstrated at least some decrease in energy 
transmitted through the water column, NMFS will continue to permit 
appropriate source level reductions during impact driving for both 
Level A

[[Page 36525]]

and Level B harassment. Furthermore, if there are no reductions 
permitted when using bubble curtains, applicants would have less 
incentive to employ them at all. Without bubble curtains, more energy 
will likely be transmitted into both the near field and far field, 
potentially increasing the risk of animal's exposure to sound at Level 
A and Level B harassment levels.
    Comment 10: The Commission commented that the method NMFS used to 
estimate the numbers of takes during the proposed activities, which 
summed fractions of takes for each species across project days, does 
not account for and negates the intent of NMFS' 24-hour reset policy. 
The Commission also recommends that NMFS develop and share guidance on 
this issue.
    Response: NMFS has shared our internal guidance on rounding and the 
consideration of qualitative factors in take estimation with the 
Commission and further, as noted, disagrees with the assertion that the 
method described is at odds with what the Commission terms NMFS' ``24-
hour reset policy.''
    Comment 11: The Commission requested clarification of certain 
issues associated with NMFS's notice that one-year renewals could be 
issued in certain limited circumstances and expressed concern that the 
renewal process, as proposed, would bypass the public notice and 
comment requirements. The Commission recommended that instead of 
bypassing comment, NMFS utilize abbreviated Federal Register notices, 
as have been used recently to solicit comment on actions that meet the 
renewal criteria. The Commission also suggested that NMFS should 
discuss the possibility of renewals through a more general route, such 
as a rulemaking, instead of notice in a specific authorization. The 
Commission further recommended that if NMFS did not pursue a more 
general route, that the agency provide the Commission and the public 
with a legal analysis supporting our conclusion that this process is 
consistent with the requirements of section 101(a)(5)(D) of the MMPA.
    Response: The proposed process of issuing a renewal IHA does not 
bypass the public notice and comment requirements of the MMPA. The 
notice of the proposed IHA expressly notifies the public that under 
certain, limited conditions an applicant could seek a renewal IHA for 
an additional year. The notice describes the conditions under which 
such a renewal request could be considered and expressly seeks public 
comment in the event such a renewal is sought. Additional reference to 
this solicitation of public comment has recently been added at the 
beginning of FR notices that consider renewals. NMFS appreciates the 
streamlining achieved by the use of abbreviated FR notices and intends 
to continue using them for proposed IHAs that include minor changes 
from previously issued IHAs, but which do not satisfy the renewal 
requirements. However, we believe our proposed method for issuing 
renewals meets statutory requirements and maximizes efficiency. Note 
that such renewals would be limited to where the activities are 
identical or nearly identical to those analyzed in the proposed IHA, 
monitoring does not indicate impacts that were not previously analyzed 
and authorized, and the mitigation and monitoring requirements remain 
the same, all of which allow the public to comment on the 
appropriateness and effects of a renewal at the same time the public 
provides comments on the initial IHA. NMFS has, however, modified the 
language for future proposed IHAs to clarify that all IHAs, including 
renewal IHAs, are valid for no more than one year and that the agency 
would consider only one renewal for a project at this time. In 
addition, notice of issuance or denial of a renewal IHA would be 
published in the Federal Register, as are all IHAs. Last, NMFS will 
publish on our website a description of the renewal process before any 
renewal is issued utilizing the new process.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical 
and behavioral descriptions) may be found on NMFS's website 
(www.nmfs.noaa.gov/pr/species/mammals/).
    Table 2 lists all species with expected potential for occurrence 
near the PTST project location 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 (2016). 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 United States waters. All managed stocks in this region are 
assessed in NMFS's United States Atlantic and Gulf of Mexico Marine 
Mammal Stock Assessments (Hayes et al., 2017a,b). All values presented 
in Table 2 are the most recent available at the time of publication and 
are available in the 2016 Stock Assessment Report (Hayes et al., 2017a) 
and draft 2017 stock assessment report (Hayes et al. 2017b) (available 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                          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......  Eubalaena glacialis....  Western North Atlantic   E/D; Y              458 (0; 455; 2017)....        1.4         36
                                                                (WNA).

[[Page 36526]]

 
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Gulf of Maine..........  -; N                335 (0.42; 239; 2012).        3.7        8.5
    Fin whale.......................  Balaenoptera physalus..  WNA....................  E/D; Y              1,618 (0.33; 1,234;           2.5       2.65
                                                                                                             2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin..............  Tursiops spp...........  WNA Coastal, Northern    D; Y                11,548 (0.36; 8,620;           86    1.0-7.5
                                                                Migratory.                                   2010-11).
                                                               WNA Coastal, Southern    D; Y                9,173 (0.46; 6,326;            63       0-12
                                                                Migratory.                                   2010-11).
                                                               Northern North Carolina  D; S                823 (0.06; 782; 2013).        7.8   1.0-16.7
                                                                Estuarine System.
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of     -; N                79,833 (0.32; 61,415;         706        307
                                                                Fundy.                                       2011).                               (0.16)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  WNA....................  -; N                75,834 (0.1; 66,884,        2,006        368
                                                                                                             2012).
    Gray seal.......................  Halichoerus grypus.....  WNA....................  -; N                27,131 (.1, 25,908,         1,554      5,207
                                                                                                             2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual 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.
Note: Italicized species are not expected to be taken or authorized for take.

    All species that could potentially occur in the planned project 
areas are included in Table 2. However, the occurrence of endangered 
North Atlantic right whales and endangered fin whales is such that take 
is not expected to occur, and they are not discussed further beyond the 
explanation provided here. Between 1998 and 2013, there were no reports 
of North Atlantic right whale strandings within the Chesapeake Bay and 
only four reported standings along the coast of Virginia. During this 
same period, only six fin whale strandings were recorded within the 
Chesapeake Bay (Barco and Swingle 2014). In 2016, there were no reports 
of fin whale strandings (Barco et al., 2017). Due to the low occurrence 
of North Atlantic right whales and fin whales, NMFS is not authorizing 
take of these species.
    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 (83 FR 18777; April 30, 2018); since that time, we are not 
aware of any changes in the status of these species and stocks; 
therefore, detailed descriptions are not provided here. Please refer to 
that Federal Register notice for these descriptions. Please also refer 
to NMFS' website (www.nmfs.noaa.gov/pr/species/mammals/) for 
generalized species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from pile driving and removal 
activities for the planned project have the potential to result in 
behavioral harassment of marine mammals in the vicinity of the action 
area. The Federal Register notice for the proposed IHA (83 FR 18777; 
April 30, 2018) included a discussion of the effects of anthropogenic 
noise on marine mammals. The project would not result in permanent 
impacts to habitats used directly by marine mammals, such as haulout 
sites, but may have potential short-term impacts to food sources such 
as forage fish and minor impacts to the immediate substrate during 
installation and removal of piles. These potential effects are 
discussed in detail in the Federal Register notice for the proposed IHA 
(83 FR 18777; April 30, 2018) therefore that information is not 
repeated here; please refer to that Federal Register notice 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 would be by Level B harassment, in the form of 
disruption of behavioral patterns for individual

[[Page 36527]]

marine mammals resulting from exposure to acoustic sources including 
impact and vibratory pile driving equipment. There is also potential 
for auditory injury (Level A harassment) to result, due to larger 
predicted auditory injury zones. The mitigation and monitoring measures 
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.
    Described in the most basic way, 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. Below, we describe these 
components 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 can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2011). 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, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., impact pile driving, seismic 
airguns) or intermittent (e.g., scientific sonar) sources.
    CTJV's planned activity includes the use of continuous (vibratory 
pile driving) and impulsive (impact pile driving) sources, and 
therefore the 120 and 160 dB re 1 [mu]Pa (rms) are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Technical Guidance, 2016) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
CTJV's tunnel project includes the use of impulsive (impact hammer) and 
non-impulsive (vibratory hammer) 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 2016 Technical Guidance, which may be accessed at: 
http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

                     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       Cell 2: LE,LF,24h: 199 dB.
                                          dB;LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (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.
    Pile driving will generate underwater noise that potentially could 
result in disturbance to marine mammals swimming by the project area. 
Transmission loss (TL) underwater is the decrease in acoustic intensity 
as an acoustic pressure wave propagates out from a source until the 
source becomes indistinguishable from ambient sound. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. A standard sound propagation model, the Practical 
Spreading Loss model, was used to estimate the range from pile driving 
activity to various expected SPLs at potential project structures. This 
model follows a geometric propagation loss based on the distance from 
the driven pile, resulting in a 4.5 dB reduction in level for each 
doubling of distance from the source. In this model, the SPL at some 
distance away from the source (e.g., driven pile) is governed by a 
measured source level, minus the TL of the energy as it dissipates with 
distance. The TL equation is:


[[Page 36528]]


TL = 15log10(R1/R2)

Where:

TL is the transmission loss in dB,
R1 is the distance of the modeled SPL from the driven 
pile, and
R2 is the distance from the driven pile of the initial 
measurement.

    The degree to which underwater noise propagates away from a noise 
source is dependent on a variety of factors, most notably by the water 
bathymetry and presence or absence of reflective or absorptive 
conditions including the sea surface and sediment type. The TL model 
described above was used to calculate the expected noise propagation 
from both impact and vibratory pile driving, using representative 
source levels to estimate the harassment zone or area exceeding 
specified noise criteria.
    Sound source levels from the PTST project site were not available. 
Therefore, literature values published for projects similar to the PTST 
project were used to estimate the amount of sound (RMS SPL) that could 
potentially be produced. The PTST Project will use round, 36-inch-
diameter, hollow steel piles and 28-inch wide sheet piles. Data 
reported in the Compendium of Pile Driving Sound Data (Caltrans 2015) 
for similar piles size and types are shown in Table 4. The use of an 
encased bubble curtain is expected to reduce sound levels by 10 
decibels (dB) (NAVFAC 2014, ICF Jones and Stokes 2009). Using data from 
previous projects (Caltrans 2015) and the amount of sound reduction 
expected from each of the sound mitigation methods, we estimated the 
peak noise level (SPLpeak), the root mean squared sound pressure level 
(RMS SPL), and the single strike sound exposure level (sSEL) for each 
pile driving scenario of the PTST project (Table 4).

                    Table 4--The Sound Levels (dB Peak, dB RMS, and dB Ssel) Expected To Be Generated by Each Hammer Type/Mitigation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                 Estimated
                                                                       Estimated                   single
                                                          Estimated    cumulative   Estimated      strike
           Type of pile                 Hammer type       peak noise     sound       pressure      sound     Relevant piles at the      Pile function
                                                          level (dB     exposure    level (dB     exposure        PTST project
                                                            peak)      level (dB       RMS)      level (dB
                                                                         cSEL)                     sSEL)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch Steel Pipe...............  Impact \a\..........          210           NA          193          183  Battered.............  Mooring dolphins.
36-inch Steel Pipe...............  Impact with Bubble            200           NA          183          173  Plumb................  Mooring dolphins and
                                    Curtain \b\.                                                                                     Temporary Pier.
24-inch AZ Sheet.................  Vibratory \c\.......          182           NA          155          155  Sheet................  Containment
                                                                                                                                     Structure.
36-inch Steel Pipe and 36-inch     Impact w/Bubble               200           NA          183          183  Plumb................  Mooring Dolphins,
 Steel Pipe.                        Curtain at PI 1 and                                                                              Temporary Pier.
                                    PI 2.
36-inch Steel Pipe and 24-inch AZ  Impact w/Bubble               200           NA          183          183  Plumb and Sheet......  Mooring Dolphins,
 Sheet Pile.                        Curtain at PI 1 and                                                                              Containment
                                    Vibratory at PI 2.                                                                               Structure.
36-inch Steel Pipe and 24-inch AZ  Vibratory at PI 1             200           NA          183          183  Plumb and Sheet......  Mooring Dolphins and
 Sheet Pile.                        and Impact w/Bubble                                                                              Containment
                                    Curtain at PI 2.                                                                                 Structure.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Examples from Caltrans 2015. These examples were the loudest provided in the Caltrans 2015 compendium for 36-inch-diameter hollow steel piles and in
  the Proxy Source Sound Levels and Potential Bubble Curtain Attenuation for Acoustic Modeling of nearshore marine Pile Driving at Navy Installations in
  Puget Sound (NAVFAC 2014).
\b\ Estimates of sound produced from impact that use sound mitigation measures were developed by subtracting 10 dB for an encased bubble curtain (ICF
  Jones and Stokes 2009, NAVFAC 2014). A 10-dB reduction in sound for this sound mitigation method is the minimum that may be expected and, therefore,
  represents a conservative estimate in sound reduction.
\c\ Example from NAVFAC 2017. Average 1-second and 10-second Broadband RMS SPL (dB re 1 [micro]Pa) for Vibratory Pile-Driving normalized to 10 meters at
  JEB Little Creek.

    When NMFS's 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 will result in some degree of 
overestimate of Level A take. However, these tools offer the best way 
to predict appropriate isopleths when more sophisticated 3D modeling 
methods are not available, and NMFS continues to develop ways to 
quantitatively refine these tools, and will qualitatively address the 
output where appropriate. For stationary sources, NMFS's User 
Spreadsheet predicts the closest distance at which, if a marine mammal 
remained at that distance the whole duration of the activity, it would 
not incur PTS. Inputs used in the User Spreadsheet, and the resulting 
isopleths are reported below.
    The Impact Pile Driving (Stationary Source: Impulsive, 
Intermittent) (Sheet E.1) spreadsheet provided by NOAA Fisheries 
requires inputs for assorted variables which are shown in Table 4. RMS 
SPL's for simultaneous pile driving were determined using the rules for 
decibel addition (WSDOT 2017). The expected number of steel piles 
driven during a 24-hour period would be a maximum of eight for plumb 
piles and three for battered piles for each portal island. Practical 
spreading was assumed (15logR) and a pulse duration of 0.1 seconds 
utilized. The distance from the source where the literature based RMS 
SPL was 10 meters while the number of strikes per pile was 1,000. Model 
outputs delineating PTS isopleths are provided in Table 6 assuming 
impact installation of three battered round steel piles per day and 
eight plumb round steel piles per day as well as vibratory installation 
of up to eight sheets per day over eight hours.
    The Optional User Spreadsheet for vibratory pile driving (non-
impulsive, stationary, continuous) (Sheet A) requires inputs for the 
sound pressure level of the source (dB RMS SPL), the expected activity 
duration in hours during per 24-hour period, the propagation of the 
sound and the distance from the source at which the sound pressure 
level was measured. Calculations also assumed that the expected 
activity level duration would be eight hours per Portal Island per 24-
hour period. Practical spreading was assumed and the measured distance 
from the sound source was 10 meters.
    The inputs from Table 5 determined isopleths where PTS from 
underwater sound during impact and vibratory driving as shown in Table 
6. Note that

[[Page 36529]]

in the Federal Register notice of proposed IHA (83 FR 18777; April 30, 
2018) a source value of 154 dB RMS SPL was used for vibratory 
installation of 28-inch sheet piles and a value of 186 dB RMS SPL was 
used for simultaneous impact installation of 36-inch steel piles 
employing bubble curtains. NMFS opted to use a higher source level of 
155 dB RMS SPL. Since the vibratory source levels based on root-mean-
square sound pressure levels (SPLrms) and sound exposure levels metrics 
were not the same value in NAVFAC 2017, neither were the source levels 
based on 1-sec and 10-sec averages. These metrics should be represented 
by the same value. When a difference is reported, it likely is due to 
the operator averaging decibels rather than taking the linear average 
of the pressures/intensities and then converting to dB. Therefore, the 
higher source level has been adopted in this notice.
    A source value of 186 dB RMS SPL was used to estimate the extents 
of the Level A harassment zone during simultaneous impact driving of 
two piles. NMFS incorrectly added 3 dB to the impact driving source 
levels rather than assuming the proxy source level (186 vs. 183 dB). 
NMFS has reverted to using a proxy source level of 183 dB re 1 
[micro]Pa when estimating the extent of the Level A harassment zone 
during simultaneous impact driving of two piles with bubble curtains. 
These revisions have been included in Table 4 and Table 5. Table 6 
shows user spreadsheet outputs of the radial distance from piles driven 
from Portal Island 1 and Portal Island 2 to PTS isopleths.

                                        Table 5--User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                   E.1: Impact pile                        E.1: Impact pile    E.1: Impact pile
                                        driving          A: Stationary          driving             driving
      Spreadsheet tab used            (stationary        source: non-         (stationary         (stationary
                                  source: impulsive,      impulsive,      source: impulsive,  source: impulsive,
                                     intermittent)        continuous         intermittent)       intermittent)
----------------------------------------------------------------------------------------------------------------
Pile Type and Hammer Type.......  36-in steel impact  28-in sheet         36-in steel impact  36-in steel impact
                                   (battered pile).    vibratory.          w/bubble curtain    w/bubble curtain
                                                                           at P1 and P2        at P1 (plumb
                                                                           (plumb piles).      pile) and sheet
                                                                                               pile vibratory at
                                                                                               P2.
Source Level (RMS SPL)..........  193...............  155...............  183...............  183.
Weighting Factor Adjustment       2.................  2.5...............  2.................  2.
 (kHz).
Number of strikes in 1 h OR       1,000.............  NA................  1,000.............  1,000.
 number of strikes per pile.
Activity Duration (h) within 24-  3 steel piles.....  8 hours/8 sheets..  8 steel piles per   8 steel piles.
 h period OR number of piles per                                           portal island (16
 day.                                                                      total).
Propagation (xLogR).............  15................  15................  15................  15.
Distance of source level          10................  10................  10................  10.
 measurement (meters).
Pulse Duration (seconds)........  0.1...............  NA................  0.1...............  0.1.
----------------------------------------------------------------------------------------------------------------


              Table 6--Radial Distance (Meters) From Pile Driven From Portal Island 1 (PI 1) and Portal Island 2 (PI 2) to PTS Isopleths *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Low-frequency           Mid-frequency          High-frequency         Phocid pinnipeds
                                           cetaceans               cetaceans               cetaceans       ------------------------  Applicable piles in
            Hammer type            ------------------------------------------------------------------------                           the PTST project
                                     Island 1    Island 2    Island 1    Island 2    Island 1    Island 2    Island 1    Island 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (battered) at PI 1 OR PI 2.     2,077.2     2,077.2        73.9        73.9     2,474.3     2,474.3     1,111.6     1,111.6  Battered Piles for
                                                                                                                                     Mooring Dolphins.
Vibratory.........................        10.9        10.9         1.0         1.0        16.1        16.1         6.6         6.6  Sheet Piles for
                                                                                                                                     Containment.
Impact w/Bubble Curtain (plumb)        1,366.1     1,366.1        48.6        48.6     1,627.2     1,627.2       731.1       731.1  Plumb Piles for
 simultaneous at PI 1 and PI 2.                                                                                                      temporary pier.
Impact w/Bubble Curtain (plumb)          860.6        10.9        30.6         1.0     1,025.1        16.1       460.5         6.6  Plumb Piles for
 simultaneous at PI 1 and                                                                                                            Temporary Pier and
 Vibratory at PI 2.                                                                                                                  Mooring Dolphins;
                                                                                                                                     Sheet Pile for
                                                                                                                                     Containment.
Vibratory at PI 1 and Impact w/           10.9       860.6         1.0        30.6       16.18     1,025.1         6.6       460.5  Plumb Piles for
 Bubble Curtain (plumb) at PI 2                                                                                                      temporary pier and
 Simultaneous.                                                                                                                       Mooring Dolphins;
                                                                                                                                     Sheet Pile for
                                                                                                                                     Containment.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Distances based on up to 3 battered round steel piles per day, 8 plumb round steel piles per day, and up to 8 sheets per day over 8 hours.

    Table 7 shows the radial distance to Level B isopleths and Table 8 
shows the areas of ensonified Level B zones associated with each of the 
planned driving scenarios.

    Table 7--Radial Distance (Meters) From Driven Pile(s) to Level B Isopleths 1 for Cetaceans and Pinnipeds
----------------------------------------------------------------------------------------------------------------
                                                      Radial distance (m)
         Hammer type driving scenario          --------------------------------   Applicable piles in the PTST
                                                   Island 1        Island 2                  project
----------------------------------------------------------------------------------------------------------------
Impact (battered).............................         1,584.9         1,584.9  Battered Piles for Mooring
                                                                                 Dolphins.
Vibratory.....................................         2,154.4         2,154.4  Sheet Piles for Containment.
Impact w/Bubble Curtain (plumb) at PI 1 and PI           341.5           341.5  Plumb Piles for temporary pier.
 2 simultaneous.

[[Page 36530]]

 
Impact w/Bubble Curtain (plumb) at PI 1 and              341.5         2,154.4  Plumb Piles for Temporary Pier
 Vibratory at PI 2 simultaneous.                                                 and Mooring Dolphins; Sheet
                                                                                 Pile for Containment.
Vibratory at PI 1 and Impact w/Bubble Curtain          2,154.4           341.5  Plumb Piles for temporary pier
 (plumb) at PI 2 simultaneous.                                                   and Mooring Dolphins; Sheet
                                                                                 Pile for Containment.
----------------------------------------------------------------------------------------------------------------
\1\ Level B harassment thresholds--160 dB for impact driving/120 dB for vibratory driving.


 Table 8--Level B Areas (km2) for All Pile Driving Scenarios Planned for
                         Use During PTST Project
------------------------------------------------------------------------
                                                             Zone size
                        Scenario                              (km\2\)
------------------------------------------------------------------------
Impact Simultaneous Plumb...............................            0.88
Impact Battered.........................................            8.27
Vibratory Sheet.........................................       \1\ 16.49
Simultaneous Vibratory Sheet and Impact Plumb...........           16.49
------------------------------------------------------------------------
\1\ Level B ensonified area at Portal Island 1 = 16.37 km2 and at Portal
  Island 2 = 16.49 km2. For the purposes of this IHA, NMFS will
  conservatively assume that the ensonified area at both Portal Islands
  = 16.49 km2.

    To calculate level B disturbance zones for airborne noise from pile 
driving, the spherical spreading loss equation (20LogR) was used to 
determine the Level B zones. The airborne noise threshold for 
behavioral harassment for all pinnipeds, except harbor seals, is 100 dB 
RMS re 20 [micro]Pa (unweighted) and for harbor seals is 90 dB RMS re 
20 [micro]Pa (unweighted).
    Literature estimates were used to estimate the amount of in-air 
sound produced from driving a pile above the MHW line (Laughlin 
2010a,b). Hollow steel piles that were 30 inches in diameter were used 
as a close proxy to the 36-inch-diameter hollow steel piles that will 
be driven at the PTST project. AZ 24-inch sheet pile was used as a 
proxy for the sheet pile to be driven during the PTST Project (Table 
9). Using the spherical spreading loss model with these estimates, 
Level B isopleths were estimated as shown below in Table 9. Note that 
the take estimates for pinnipeds were based on surveys which included 
counts of hauled out animals. Therefore, to avoid double counting, 
airborne exposures are not evaluated further for purposes of estimating 
take under the issued IHA. During any upland pile driving before 
issuance of the IHA, however, shutdown will occur whenever pinnipeds 
enter into the Level B zones as depicted below to avoid unauthorized 
take.

  Table 9--Radial Distance (Meters) from Pile Driven Above MHW to Level B Sound Thresholds for Harbor Seals and
                                                   Gray Seals
----------------------------------------------------------------------------------------------------------------
                                                                      Level A       Level B harassment zone (m)
                Source                         Sound level          harassment   -------------------------------
                                                                     zone (m)      Harbor seals     Gray seals
----------------------------------------------------------------------------------------------------------------
Impact Hammer 36- inch Pile...........  110 dBL5SEQ at 15m\a\...             N/A             150              47
Vibratory Hammer Assumed equivalent to  92 dBL5SEQ at 15m.......             N/A              19               6
 24-in sheet.
----------------------------------------------------------------------------------------------------------------
\a\Laughlin 2010a,b as cited in City of Unalaska 2016 IHA for Unalaska Marine Center.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    Humpback whales are relatively rare in the Chesapeake Bay but may 
be found within or near the Chesapeake Bay at any time of the year. 
Between 1998 and 2014, 11 humpback whale strandings were reported 
within the Chesapeake Bay (Barco and Swingle 2014). Strandings occurred 
in all seasons, but were most common in the spring. There is no 
existing density data for this species within or near the Chesapeake 
Bay. Populations in the mid-Atlantic have been estimated for humpback 
whales off the coast of New Jersey with a density of 0.00013 per square 
kilometer (Whitt et al., 2015). A similar density may be expected off 
the coast of Virginia.
    Bottlenose dolphins are abundant along the Virginia coast and 
within the Chesapeake Bay and can be seen seen annually in Virginia 
from May through October. Approximately 65 strandings are reported each 
year (Barco and Swingle 2014). Stranded bottlenose dolphins have been 
recorded as far north as the Potomac River in the Chesapeake Bay 
(Blaylock 1985). A 2016 Navy report on the occurrence, distribution, 
and density of marine mammals near Naval Station Norfolk and Virginia 
Beach, Virginia provides seasonal densities of bottlenose dolphins for 
inshore areas in the vicinity of the project area (Engelhaupt et al., 
2016) (Table 10).
    There is little data on the occurrence of harbor porpoises in the 
Chesapeake Bay. Harbor porpoises are the second most common marine 
mammal to strand in Virginia waters with 58 reported strandings between 
2007 through 2016. Unlike bottlenose dolphins, harbor porpoises are 
found in Virginia in the cooler months, primarily late winter and early 
spring, and they strand primarily on ocean facing beaches (Barco et 
al., 2017). Given the lack of abundance data, NMFS assumed that a 
limited number of harbor porpoises (2) would be taken during each month 
of planned construction in order to generate a take estimate for this 
species.
    Harbor seals are the most common seal in Virginia (Barco and 
Swingle 2014). They can be seen resting on the rocks around the portal 
islands of the CBBT from December through April. They are unlikely to 
occur in the project area in the summer and early fall.

[[Page 36531]]

Survey data for in-water and hauled out harbor seals was collected by 
the United States Navy at the CBBT portal islands from 2014 through 
2016 (Rees et al., 2016) (Table 12). Surveys reported 112 harbor seals 
in the 2014/2015 season, 185 harbor seals during the 2015/2016 season, 
and 307 during the 2016/2017 season. (Rees et al., 2016; Rees et al. 
2017).
    Gray seals are uncommon in Virginia and the Chesapeake Bay with 
only 15 gray seal strandings documented in Virginia from 1988-2013 
(Barco and Swingle 2014). They are rarely found resting on the rocks 
around the portal islands of the CBBT from December through April 
alongside harbor seals. Observation surveys conducted by the Navy at 
the CBBT portal islands recorded one gray seal in the 2014/2015, two 
gray seals in 2015/2016, and two gray seals in 2016/2017 seasons (Rees 
et al., 2016; Rees et al. 2017).

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    The following assumptions are made when estimating potential 
incidences of take:
     All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
     An individual can only be taken once during a 24-h period;
     Exposures to sound levels at or above the relevant 
thresholds equate to take, as defined by the MMPA.

Humpback Whale

    As noted previously, humpback whales are rare in the Chesapeake 
Bay, although they do occur. Density off of the coast of New Jersey, 
and presumably Virginia and Maryland, is extremely low (0.00013 
animals/km\2\). Because density is extremely low, CTJV has requested 
and NMFS is authorizing one Level B take every two months for the 
duration of in-water pile driving activities. Pile driving activities 
are expected to occur over a 10-month period. Therefore, a total of 5 
Level B takes of humpback whales is authorized by NMFS.

Bottlenose Dolphin

    Total number of takes for bottlenose dolphin were calculated using 
the seasonal density described above (individuals/km\2\/day) of animals 
within the inshore study area at the mouth of the Chesapeake Bay 
(Englehaupt et al., 2016). Project specific dolphin densities were 
calculated within the respective Level B harassment zone and season. 
Densities were then used to calculate the seasonal takes based on the 
number and type of pile driving days per season. For example, the 
density of dolphins in summer months is assumed to be 3.55 dolphins/
km\2\ * 0.88 km\2\ (harassment zone for Simultaneous Plumb Pile driving 
as shown in Table 8) = 3.12 dolphins/km\2\ per day in summer as shown 
in Table 11. This density was then multiplied by number of simultaneous 
plumb pile driving days to provide takes for that season (e.g. 3.12 
dolphins/km\2\ * 24 days = 74.88 estimated summer exposures from 
simultaneous plumb pile driving). The sum of the anticipated number of 
seasonal takes resulted in 4,740 estimated exposures as shown in Table 
10 split among three stocks. There is insufficient information to 
apportion the takes precisely to the three stocks present in the area. 
Given that members of the NNCES stock are thought to occur in or near 
the Bay in very small numbers, and only during July and August, we will 
conservatively assume that no more than 100 of the takes will be from 
this stock. Most animals from this stock spend the summer months in 
Pamlico Sound and the range of species extends as far south as 
Beaufort, NC. In colder months, animals are thought to go no farther 
north than Pamlico Sound. Since members of the southern migratory 
coastal and northern migratory coastal stocks are known to occur in or 
near the Bay in greater numbers, we will conservatively assume that no 
more than half of the remaining animals (2,320) will accrue to either 
of these stocks. The largest level B zone for mid-frequency cetaceans 
occurs during vibratory driving and extends out 2,154.4 meters. The 
largest Level A isopleth is 73.9 meters and would occur during 
installation of three battered piles on a single day. NMFS proposes a 
shutdown zone that extends 200 m, so no Level A take is authorized.

                 Table 10--Summary of Information Used To Calculate Bottlenose Dolphin Exposures
----------------------------------------------------------------------------------------------------------------
                                                                      Density        Estimated     Total number
                             Season                                (individuals   number of pile   of requested
                                                                    per km\2\)     driving days        takes
----------------------------------------------------------------------------------------------------------------
Summer 2018.....................................................            3.55              45          866.37
Fall 2018.......................................................            3.88              77         2745.94
Winter 2019.....................................................            0.63              70          962.62
Spring 2019.....................................................            1.00              10           194.9
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............           4,740
----------------------------------------------------------------------------------------------------------------


        Table 11--Seasonal Daily Take by Driving Scenario (Seasonal Density * Scenario Zone Size) and Estimated Number of Driving Days per Season
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                        Simultaneous
                                                                     Impact         Impact batter    Vibratory sheet   vibratory sheet
                            Season                                simultaneous    daily take (days/ daily take (days/ and impact plumb   Number of pile
                                                                plumb daily take       season)           season)      daily take (days/   driving days
                                                                  (days/season)                                            season)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Summer........................................................         3.12 (24)        29.35 (15)         58.54 (6)         58.54 (0)                45
Fall..........................................................         3.41 (36)         32.10 (0)        63.98 (41)         63.98 (0)                77
Winter........................................................         0.55 (12)          5.21 (0)        10.39 (34)        10.39 (24)                70
Spring........................................................          0.88 (0)          8.27 (0)         16.49 (9)         16.49 (1)                10
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 36532]]

Harbor Porpoise

    Little is known about the abundance of harbor porpoises in the 
Chesapeake Bay. A recent survey of the Maryland Wind Energy Area found 
that porpoises occur frequently offshore January to May (Wingfield et 
al., 2017). This finding reflects the pattern of winter and spring 
strandings in the mid-Atlantic. NMFS will assume that there is a 
porpoise sighting once during every two months of operations. That 
would equate to five sightings over ten months. Assuming an average 
group size of two results in a total estimated take of 10 porpoises. 
Harbor porpoises are members of the high-frequency hearing group which 
would have Level A isopleths as large of 2,474 meters during impact 
installation of three battered piles per day. Given the relatively 
large Level A zones during impact driving, NMFS will assume that 40 
precent of porpoises are taken by Level A harassment. Therefore, NMFS 
authorizes the take of 4 porpoises by Level A take and 6 porpoises by 
Level B take.

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 in 
2016 and 2017 (Rees et al., 2017). The survey data revealed a maximum 
of 40 animals observed per day. The maximum number of seals per day 
(40) was multiplied by the total number of driving days (202) resulting 
in an estimated 8,080 harbor seal takes. The largest level B zone would 
occur during vibratory driving and extends out 2,154.4 meters from the 
sound source. The largest Level A isopleth is 1,111.6 meters which 
would occur during impact installation of three battered piles. The 
smallest Level A zone during impact driving is 6.6 meters meters which 
would occur when a single steel pile is impact driven at the same time 
that vibratory driving of sheet piles is occurring. NMFS authorized a 
shutdown zone for harbor seals of 15 meters 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. NMFS will assume that 40 percent of the exposed seals 
will occur within the Level A zone specified for a given scenario. 
Therefore, NMFS authorizes the Level A take of 3,232 and Level B take 
of 4,848 harbor seals.

Gray Seals

    The number of gray seals potentially exposed to Level B harassment 
in the project area was calculated using survey data recording gray 
seal observations was collected by the U.S. Navy at the portal islands 
from 2014 through 2016 (Rees et al., 2016). Potential gray seal 
exposures were calculated as the number of potential seals per pile 
driving day (8 hours) multiplied by the number of pile driving days per 
month. The anticipated numbers of monthly exposures as shown in Table 
13 were summed. Therefore, NMFS has authorized the take of 67 gray 
seals by Level B harassment. The Level A isopleths for gray seals are 
identical to those for harbor seals. With a shutdown zone of 15 meters, 
NMFS recommended the Level A take of 40 percent of gray seals. 
Therefore, NMFS authorizes the Level A take of 27 and Level B take of 
40 gray seals.

                           Table 13--Calculation for the Number of Gray Seal Exposures
----------------------------------------------------------------------------------------------------------------
                                                                                    Total pile
                                                                                   driving days
                                                                     Estimated       per month       Gray seal
                              Month                               seals per work     (includes         takes
                                                                        day           upland
                                                                                     driving)
----------------------------------------------------------------------------------------------------------------
June 2018.......................................................         Seals not expected to be present.
July 2018.......................................................         Seals not expected to be present.
August 2018.....................................................         Seals not expected to be present.
September 2018..................................................         Seals not expected to be present.
October 2018....................................................         Seals not expected to be present.
                                                                 -----------------------------------------------
November 2018...................................................               0              27               0
December 2018...................................................               0              24               0
January 2019....................................................               0              42               0
February 2019...................................................             1.6              42              67
March 2019......................................................               0              11               0
----------------------------------------------------------------------------------------------------------------

    Table 14 provides a summary of authorized Level B takes as well as 
the percentage of a stock or population authorized for take.

                         Table 14--Authorized Take and Percentage of Stock or Population
----------------------------------------------------------------------------------------------------------------
                                                                    Authorized      Authorized        Percent
                Species                           Stock            Level A takes   Level B takes    population
----------------------------------------------------------------------------------------------------------------
Humpback whale........................  Gulf of Maine...........  ..............               5             1.5
Bottlenose dolphin....................  WNA Coastal, Northern     ..............           2,320            20.1
                                         Migratory.
                                        WNA Coastal, Southern     ..............           2,320            25.2
                                         Migratory.
                                        NNCES...................  ..............             100            12.1
Harbor porpoise.......................  Gulf of Maine/Bay of                   4               6           <0.01
                                         Fundy.
Harbor seal...........................  Western North Atlantic..           3,232           4,848            10.6
Gray seal.............................  Western North Atlantic..              27              40            0.25
----------------------------------------------------------------------------------------------------------------


[[Page 36533]]

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.
    The following mitigation measures are contained in the IHA:
     Pile Driving Delay/Shutdown Zone--For in-water heavy 
machinery work (using, e.g., standard barges, tug boats, barge-mounted 
excavators, or clamshell equipment used to place or remove material), a 
minimum 10 meters shutdown zone shall be implemented. If a marine 
mammal comes within 10 meters of such operations, 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 (but is not limited to) the following activities: (1) Vibratory 
pile driving; (2) movement of the barge to the pile location; (3) 
positioning of the pile on the substrate via a crane (i.e., stabbing 
the pile); or (4) removal of the pile from the water column/substrate 
via a crane (i.e., deadpull).
     Non-authorized Take Prohibited--If a species for which 
authorization has not been granted (e.g., North Atlantic right whale, 
fin whale) or a species for which authorization has been granted but 
the authorized takes are met, is observed approaching or within the 
Level B Isopleth, pile driving and removal activities must shut down 
immediately using delay and shut-down procedures. Activities must not 
resume until the animal has been confirmed to have left the area or an 
observation time period of 15 minutes has elapsed.
     Use of Impact Installation--During pile installation of 
hollow steel piles, an impact hammer rather than a vibratory hammer 
will be used to reduce the duration of pile driving decrease the ZOI 
for marine mammals.
     Cushion Blocks--Use of cushion blocks will be required 
during impact installation. Cushion blocks reduce source levels and, by 
association, received levels, although exact decreases in sound levels 
are unknown.
     Use of Bubble Curtain--An encased bubble curtain will be 
used for impact installation of plumb round piles at water depths 
greater than 3 m (10 ft). Bubble curtains will not function effectively 
in shallower depths. shall employ a bubble curtain during impact pile 
driving of steel piles. CTJV shall implement the following performance 
standards: (1) The bubble curtain must distribute air bubbles around 
100 percent of the piling perimeter for the full depth of the water 
column; (2) the lowest bubble ring shall be in contact with the mudline 
for the full circumference of the ring, and the weights attached to the 
bottom ring shall ensure 100 percent mudline contact. No parts of the 
ring or other objects shall prevent full mudline contact; and (3) CTJV 
will require that construction contractors train personnel in the 
proper balancing of air flow to the bubblers, and shall require that 
construction contractors submit an inspection/performance report for 
approval by the CTJV within 72 hours following the performance test. 
Corrections to the attenuation device to meet the performance standards 
shall occur prior to impact driving.
     Soft-Start--The use of a soft start procedure is believed 
to provide additional protection to marine mammals by warning or 
providing a chance to leave the area prior to the hammer operating at 
full capacity, and typically involves a requirement to initiate sound 
from the hammer at reduced energy followed by a waiting period. A soft-
start procedure will be used for impact pile driving at the beginning 
of each day's in-water pile driving or any time impact pile driving has 
ceased for more than 30 minutes. The CTJV will start the bubble curtain 
prior to the initiation of impact pile driving. The contractor will 
provide an initial set of strikes from the impact hammer at reduced 
energy, followed by a 30-second waiting period, then two subsequent 
sets.
     Establishment of Additional Shutdown Zones and Monitoring 
Zones--For all impact and vibratory pile driving shutdown and 
monitoring zones will be established and monitored.
     CTJV will establish a shutdown zone of 200 meters for 
common dolphins and harbor porpoises and 15 meters for harbor and gray 
seals. The shutdown zones for humpback whales are depicted in Table 16.
     For all impact and vibratory pile driving shutdown and 
monitoring zones will be established and monitored. Level B zones are 
shown in Table 15.

Table 15--Radial Distance (Meters) From Pile Driven to Level B Isopleths
                       for Cetaceans and Pinnipeds
------------------------------------------------------------------------
                                                Radial distance (m)
      Hammer type driving scenario       -------------------------------
                                             Island 1        Island 2
------------------------------------------------------------------------
Impact (battered).......................           1,585           1,585
Vibratory...............................           2,155           2,155
Impact w/Bubble Curtain (plumb) at PI 1              345             345
 and PI 2 simultaneous..................
Impact w/Bubble Curtain (plumb) at PI 1              345           2,155
 and Vibratory at PI 2 simultaneous.....

[[Page 36534]]

 
Vibratory at PI 1 and Impact w/Bubble              2,155             345
 Curtain (plumb) at PI 2 simultaneous...
------------------------------------------------------------------------

     The Level A zones will depend on the number of piles 
driven and the presence of marine mammals per 24-hour period. Up to 3 
battered piles or 8 plumb steel piles will be driven per 24-hour period 
using the following adaptive monitoring approach. Monitoring will begin 
each day using the three-pile Level A zone for battered piles (or 
eight-pile zone for plumb piles). If after the first pile is driven, no 
marine mammals have been observed in the Level A zone, then the Level A 
zone will reduce to the two-pile zone. If no marine mammals are 
observed within the two-pile shutdown zone during the driving of the 
second pile, then the Level A zone will reduce to the one-pile zone. 
However, if a mammal is observed approaching or entering the three-pile 
Level A zone during the driving of the first pile, then the three-pile 
Level A zone will be monitored for the remainder of pile driving 
activities for that day. Likewise, if a marine mammal is observed 
within the two-pile but not the three-pile Level A zone, then the two-
pile Level A zone will be monitored for the remainder of pile driving 
activities for that day. The same protocol will be followed for 
installation of up to 8 plumb piles per day.
    The Level A isopleths for all authorized species are shown in Table 
16. Isopeths associated with low-frequency cetaceans will signify 
shutdown zones for humpback whales.

     Table 16--Radial Distance (Meters) From Driven Pile to PTS Zones for Cetaceans and Phocid Pinnipeds for
                                        Scenarios Involving Impact Hammer
----------------------------------------------------------------------------------------------------------------
                                                                                                  Simultaneous
                                                                                Impact hammer       Driving--
                                                                                 with bubble    Vibratory hammer
         Class of marine mammals            Piles per day     Impact hammer        curtain         and impact
                                                             (battered pile)    simultaneous       hammer with
                                                                               (plumb pile) **   bubble curtain
                                                                                                  (plumb pile)
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans *...............                 8               N/A             1,366             860.6
                                                         7               N.A           1,249.1             787.3
                                                         6               N/A           1,127.7             710.4
                                                         5               N/A             998.6             629.1
                                                         4               N/A             860.6             542.1
                                                         3           2,077.2             710.4             447.5
                                                         2           1,585.2             542.1             341.5
                                                         1             998.6             341.5             215.1
Mid-Frequency Cetaceans.................                 8               N/A                48              30.6
                                                         7               N/A              44.4              28.0
                                                         6               N/A              40.1              25.3
                                                         5               N/A              35.5              22.4
                                                         4               N/A              30.6              19.3
                                                         3              73.9              25.3              15.9
                                                         2              56.4              19.3              12.1
                                                         1              35.5              12.1               7.7
High Frequency Cetaceans................                 8               N/A             1,627           1,025.1
                                                         7               N/A           1,488.6             937.8
                                                         6               N/A           1,343.3             846.2
                                                         5               N/A           1,189.5             749.4
                                                         4               N/A           1,025.1             645.8
                                                         3           2,474.3             846.2             533.1
                                                         2           1,888.3             645.8             406.8
                                                         1           1,189.5             406.8             256.3
Phocid Pinnipeds........................                 8               N/A               731             460.5
                                                         7               N/A              68.8             412.3
                                                         6               N/A             603.5             380.2
                                                         5               N/A             534.4             336.7
                                                         4               N/A             460.5             290.1
                                                         3           1,111.6             380.2             239.5
                                                         2             848.3             290.1             182.8
                                                         1             534.4             182.8             115.1
----------------------------------------------------------------------------------------------------------------
* These isopleths serve as shutdown zones for all large whales, including humpback and fin whales.
** Assumes 1 pile installed at each island per day ranging from maximum of 16 piles to minimum of 2 piles.


[[Page 36535]]

    Based on our evaluation of the applicant's suggested measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means effecting the least practicable 
impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
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.

Visual Monitoring

    The following visual monitoring measures are contained in the IHA:
     Pre-activity monitoring shall take place from 30 minutes 
prior to initiation of pile driving activity and post-activity 
monitoring shall continue through 30 minutes post-completion of pile 
driving activity. Pile driving may commence at the end of the 30-minute 
pre-activity monitoring period, provided observers have determined that 
the shutdown zone is clear of marine mammals, which includes delaying 
start of pile driving activities if a marine mammal is sighted in the 
zone.
     If a marine mammal approaches or enters the shutdown zone 
during activities or pre-activity monitoring, all pile driving 
activities at that location shall be halted or delayed, respectively. 
If pile driving is halted or delayed due to the presence of a marine 
mammal, the activity may not resume or commence until either the animal 
has voluntarily left and been visually confirmed beyond the shutdown 
zone and 15 minutes have passed without re-detection of the animal. 
Pile driving activities include the time to install or remove a single 
pile or series of piles, as long as the time elapsed between uses of 
the pile driving equipment is no more than thirty minutes.
     Monitoring distances, in accordance with the identified 
shutdown zones, Level A zones and Level B zones, will be determined by 
using a range finder, scope, hand-held global positioning system (GPS) 
device or landmarks with known distances from the monitoring positions.
     A minimum of two PSOs will be required during all pile 
driving activities. Monitoring locations shall be based on land both at 
Portal Island No. 1 and Portal Island No. 2 during simultaneous driving 
or on the Portal Island with active driving during non-simultaneous 
driving.
     Monitoring will be continuous unless the contractor takes 
a break longer than 2 hours from active pile and sheet pile driving, in 
which case, monitoring will be required 30 minutes prior to restarting 
pile installation.
     If marine mammals are observed, their location within the 
zones, and their reaction (if any) to pile activities will be 
documented.
     If weather or sea conditions restrict the observer's 
ability to observe, or become unsafe, pile installation will be 
suspended until conditions allow for monitoring to resume.
     For in-water pile driving, under conditions of fog or poor 
visibility that might obscure the presence of a marine mammal within 
the shutdown zone, the pile in progress will be completed and then pile 
driving suspended until visibility conditions improve.
     Monitoring of pile driving shall be conducted by qualified 
PSOs (see below), who shall have no other assigned tasks during 
monitoring periods. CVTJV shall adhere to the following conditions when 
selecting observers:
    (1) Independent PSOs shall be used (i.e., not construction 
personnel).
    (2) At least one PSO must have prior experience working as a marine 
mammal observer during construction activities.
    (3) Other PSOs may substitute education (degree in biological 
science or related field) or training for experience.
    (4) CTJV shall submit PSO CVs for approval by NMFS.
     CTJV will ensure that observers have the following 
additional qualifications:
    (1) Ability to conduct field observations and collect data 
according to assigned protocols.
    (2) Experience or training in the field identification of marine 
mammals, including the identification of behaviors.
    (3) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations.
    (4) Writing skills sufficient to prepare a report of observations 
including but not limited to the number and species of marine mammals 
observed; dates and times when in-water construction activities were 
conducted; dates, times, and reason for implementation of mitigation 
(or why mitigation was not implemented when required); and marine 
mammal behavior.
    (5) 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.
    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities. It will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated marine 
mammal observation data sheets. Specifically, the report must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;

[[Page 36536]]

     Deviation from initial proposal in pile numbers, pile 
types, average driving times, etc.;
     Weather parameters (e.g., percent cover, visibility); and
     Water conditions (e.g., sea state, tide state).
     For each marine mammal sighting:
    (1) Species, numbers, and, if possible, sex and age class of marine 
mammals;
    (2) Description of any observable marine mammal behavior patterns, 
including bearing and direction of travel and distance from pile 
driving activity;
    (3) Location and distance from pile driving activities to marine 
mammals and distance from the marine mammals to the observation point;
    (4) Estimated amount of time that the animals remained in the Level 
A Level B zone;
     Description of implementation of mitigation measures 
within each monitoring period (e.g., shutdown or delay); and
     Other human activity in the area.
     A summary of the following:
    (1) Total number of individuals of each species detected within the 
Level A and Level B Zone, and estimated as taken if correction factor 
is applied.
    (2) Daily average number of individuals of each species 
(differentiated by month as appropriate) detected within the Level A 
and Level B Zone, and estimated as taken, if correction factor is 
applied.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury, serious injury or mortality, CTJV would 
immediately cease the specified activities and report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS Greater Atlantic Region New England/Mid-
Atlantic Regional Stranding Coordinator. The report would include the 
following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with CTJV to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. CTJV would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that CTJV discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (e.g., in less than a 
moderate state of decomposition as described in the next paragraph), 
CTJV would immediately report the incident to the Chief of the Permits 
and Conservation Division, Office of Protected Resources, NMFS, and the 
NMFS Greater Atlantic Region New England/Mid-Atlantic Regional 
Stranding Coordinator. The report would include the same information 
identified in the paragraph above. Activities would be able to continue 
while NMFS reviews the circumstances of the incident. NMFS would work 
with CTJV to determine whether modifications in the activities are 
appropriate.
    In the event that CTJV discovers an injured or dead marine mammal 
and the lead PSO determines that the injury or death is not associated 
with or related to the activities authorized in the IHA (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), CTJV would report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS Greater Atlantic Region New England/Mid-
Atlantic Regional Stranding Coordinator, within 24 hours of the 
discovery. CTJV would provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network.

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).
    CTJV's planned pile driving activities are highly localized. Only a 
relatively small portion of the Chesapeake Bay may be affected. 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-related 
activities may cause some fish to leave the area of disturbance, thus 
temporarily impacting marine mammals' foraging opportunities in a 
limited portion of their foraging range, but because of the relatively 
small impacted area of the habitat range utilized by each species that 
may be affected, the impacts to marine mammal habitat are not expected 
to cause significant or long-term negative consequences.
    A limited number of animals could experience Level A harassment in 
the form of PTS if they remain within the Level A harassment zone 
during certain impact driving scenarios. The sizes of the Level A zones 
are dependent on the number of steel piles driven in a 24-hour period. 
Up to 8 steel plumb piles or 3 steel battered piles could be driven in 
a single day, which would result in a relatively large Level A zones. 
(If fewer piles are driven per day then the Level A zones would be 
smaller). However, an animal would have to be within the Level A zones 
during the driving of all 8 plumb or 3 battered piles. This is 
unlikely, as marine mammals tend to move away from sound sources. 
Furthermore, the degree of injury is expected to be mild and is not 
likely to affect the reproduction or survival of the individual 
animals. It is expected that, if hearing impairments occurs, most 
likely the affected animal

[[Page 36537]]

would lose a few dB in its hearing sensitivity, which in most cases is 
not likely to affect its survival and recruitment.
    Exposures to elevated sound levels produced during pile driving 
activities may cause behavioral responses by an animal, but they are 
expected to be mild and temporary. 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; Lerma, 2014). Most likely, individuals 
will simply 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. These reactions and behavioral changes are expected to subside 
quickly when the exposures cease. The pile driving activities analyzed 
here are similar to, or less impactful than, numerous construction 
activities conducted in numerous other locations on the east coast, 
which have taken place with no reported injuries or mortality to marine 
mammals, and no known long-term adverse consequences from behavioral 
harassment. Repeated exposures of individuals to levels of sound that 
may cause Level B harassment are unlikely to result in permanent 
hearing impairment or to significantly disrupt foraging behavior. 
Furthermore, Level B harassment will be reduced through use of 
mitigation measures described herein.
    CTJV will employ noise attenuating devices (i.e., bubble curtains, 
pile caps) during impact driving of plumb steel piles. During impact 
driving of both plumb and battered piles, implementation of soft start 
procedures and monitoring of established shutdown zones will be 
required, significantly reduces any possibility of injury. Given 
sufficient notice through use of soft start (for impact driving), 
marine mammals are expected to move away from a sound source. PSOs will 
be stationed on a portal island whenever pile driving operations are 
underway at that island. The portal island locations provide a 
relatively clear view of the shutdown zones as well as monitoring 
zones. These factors will limit exposure of animals to noise levels 
that could result in injury.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated;
     The area of potential impacts is highly localized;
     No adverse impacts to marine mammal habitat;
     The absence of any significant habitat within the project 
area, including rookeries, or known areas or features of special 
significance for foraging or reproduction;
     Anticipated incidents of Level A harassment would likely 
be mild;
     Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior; and
     The anticipated 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 
activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.
    NMFS has determined that the estimated Level B take of humpback 
whale is 1.5 percent of the Gulf of Maine stock; take of harbor seals 
is 10.6 percent of the Western North Atlantic stock; take of gray seals 
is 0.25 percent of the Western North Atlantic stock; and take of harbor 
porpoise is <0.01 percent of the Gulf of Maine/Bay of Fundy stock. 
Total estimated take of bottlenose dolphins is 4,740. NMFS assumes 100 
takes accruing to the NNCES stock and no more than half (2,300) of the 
remaining takes accruing to either of two migratory coastal stocks. 
This stock division represents 12.1 percent of the NCCES stock, 20.1 
percent of the Western North Atlantic northern migratory coastal stock 
and 25.2 percent of the Western North Atlantic southern migratory 
coastal stock. Additionally, some number of the anticipated takes are 
likely to be repeat sightings of the same individual, lowering the 
number of individuals taken.
    Based on the analysis contained herein of the planned activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) 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 the 
IHA 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.

[[Page 36538]]

    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 CTJV for conducting pile driving and 
removal activities as part of the PTST project between August 1, 2018 
through July 31, 2019, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated.

    Dated: July 25, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2018-16204 Filed 7-27-18; 8:45 am]
 BILLING CODE 3510-22-P