[Federal Register Volume 85, Number 75 (Friday, April 17, 2020)]
[Notices]
[Pages 21399-21413]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-08085]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XA055]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Old Sitka Dock North Dolphins 
Expansion Project in Sitka, Alaska

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
Halibut Point Marine Services, LLC (HPMS) to incidentally harass, by 
Level A and Level B harassment only, marine mammals during construction 
activities associated with the Old Sitka Dock North Dolphins Expansion 
Project in Sitka, Alaska.

DATES: This Authorization is effective from October 1, 2020 through 
February 28, 2021.

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

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.

[[Page 21400]]

    The definitions of all applicable MMPA statutory terms cited above 
are included in the relevant sections below.

Summary of Request

    On July 30, 2019, NMFS received a request from HPMS for an IHA to 
take marine mammals incidental to dock expansion activities. The 
application was deemed adequate and complete on October 21, 2019. 
HPMS's request is for take of a small number of seven species of marine 
mammals by Level B harassment and Level A harassment. Neither HPMS nor 
NMFS expects serious injury or mortality to result from this activity 
and, therefore, an IHA is appropriate.

Description of the Specified Activity

    HPMS is proposing to add two additional dolphin structures and 
modify two existing dolphin structures at their deep-water dock 
facility in Sitka Sound. The cruise industry is a major sector of 
Sitka's economy, and the current HPMS facility currently does not meet 
the industry-required specifications for mooring newer, larger cruise 
vessels that are becoming increasingly more common. Construction at the 
dock facility will include vibratory pile installation and removal of 
temporary, template pile structures, vibratory and impact installation 
of permanent piles comprising the dolphins, and down-the-hole drilling 
to install bedrock anchors for the permanent piles. Vibratory pile 
removal and installation, impact pile installation, and drilling 
activity will introduce underwater sounds that may result in take, by 
Level A and Level B harassment, of marine mammals across approximately 
55.9km\2\ in Sitka sound.
    A detailed description of the planned project is provided in the 
Federal Register notice for the proposed IHA (85 FR 3623; January 22, 
2020). Since that time, no changes have been made to the planned 
construction 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 HPMS was published 
in the Federal Register on January 22, 2020 (85 FR 3623). That notice 
described, in detail, HPMS's planned activity, the marine mammal 
species that may be affected by the activity, the anticipated effects 
on marine mammals and their habitat, planned amount and manner of take, 
and planned mitigation, monitoring and reporting measures. During the 
30-day public comment period, NMFS received a comment letter from the 
Marine Mammal Commission (Commission); the Commission's recommendations 
and our responses are provided here, and the comments have been posted 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. 
Please see the Commission's letter for full detail regarding 
justification for their recommendations.
    Comment 1: The Commission recommends that NMFS finish its review 
and finalize its recommended proxy source levels for both impact and 
vibratory installation of the various pile types and sizes.
    Response: NMFS concurs with the Commission's recommendation, and 
intends to finalize the referenced information as soon as possible.
    Comment 2: The Commission recommends that NMFS (1) re-estimate the 
Level A harassment zones for DTH drilling based on source levels 
provided either by Reyff and Heyvaert (2019) or Denes et al. (2019) and 
NMFS' Level A harassment thresholds for impulsive sources and (2) 
increase the numbers of Level A harassment takes accordingly. If NMFS 
believes that sufficient data are not available to characterize DTH 
drilling appropriately at this time, then the Commission recommends 
that NMFS require all applicants that propose to use a DTH hammer to 
install piles, including HPMS, to conduct in-situ measurements and 
adjust the Level A and Level B harassment zones accordingly.
    Response: In this instance, NMFS tentatively agrees that the 
limited data available support considering the applicant's use of DTH 
drilling to be an impulsive sound source for the purposes of 
calculating the Level A harassment zones. However, at this time, we do 
not agree with the specific recommendations concerning source levels, 
and have used the initial source level selected (166.2dB RMS SPL at 
10m, (Denes et al., 2016)) to calculate the Level A harassment zones 
against NMFS' Level A harassment thresholds for impulsive sources. NMFS 
updated Level A harassment takes accordingly. Please see the Estimated 
Take section for the Level A harassment zones and take calculations. 
NMFS is evaluating the available DTH drilling Sound Source Verification 
(SSV) data and will fill information gaps as possible, but is not 
requiring HPMS to conduct in-situ measurements.
    Comment 3: The Commission recommends that NMFS increase the number 
of Level A harassment takes from five to at least 10 for harbor seals 
and from five to at least 15 for harbor porpoises, notwithstanding the 
previous recommendation to revise the Level A harassment takes 
accordingly for DTH drilling. The Commission also recommends that NMFS 
increase Level B harassment takes from 532 to 627 for harbor seals, 
from 95 to 275 for harbor porpoises, and from 304 to no fewer than 627 
for Steller sea lions.
    Response: NMFS thanks the Commission for its recommendation, but 
does not concur. A complete rationale for the authorized take numbers 
is included in the Estimated Take section, below.
    Comment 4: The Commission recommends that NMFS ensure HPMS keeps a 
running tally of the total takes, based on observed and extrapolated 
takes, for both Level A and B harassment.
    Response: We agree that HPMS must ensure they do not exceed 
authorized takes but do not concur with the recommendation. NMFS is not 
responsible for ensuring that HPMS does not operate in violation of an 
issued IHA.
    Comment 5: The Commission recommends that NMFS include certain 
requirements that the Commission deems ``standard.'' Specifically, the 
Commission recommends that we include requirements that (1) HPMS 
conduct pile driving and removal activities during daylight hours only 
and (2) if the entire shutdown zone(s) is not visible due to darkness, 
fog, or heavy rain, HPMS delay or cease pile driving and removal 
activities until the zone(s) is visible.
    Response: We do not fully concur with the Commission's 
recommendations, or with their underlying justification, and do not 
adopt them as stated. While HPMS has no intention of conducting pile 
driving activities at night, it is unnecessary to preclude such 
activity should the need arise (e.g., on an emergency basis or to 
complete driving of a pile begun during daylight hours, should the 
construction operator deem it necessary to do so). Further, while 
acknowledging that prescribed mitigation measures for any specific 
action (and an associated determination that the prescribed measures 
are sufficient to achieve the least practicable adverse impact on the 
affected species or stocks and their habitat) are subject to review by 
the Commission and the public, any determination of what measures 
constitute ``standard'' mitigation requirements is NMFS' alone to make. 
Even in the context of measures that NMFS considers to be ``standard'' 
we reserve the flexibility to deviate from

[[Page 21401]]

such measures, depending on the circumstances of the action. We 
disagree with the statement that a prohibition on pile driving activity 
outside of daylight hours is necessary to meet the MMPA's least 
practicable adverse impact standard, and the Commission does not 
justify this assertion.
    As included in the draft authorization, the final authorization 
includes a measure stating that ``Should environmental conditions 
deteriorate such that marine mammals within the entire shutdown zone 
would not be visible (e.g., fog, heavy rain), pile driving and removal 
must be delayed until the PSO is confident marine mammals within the 
shutdown zone could be detected,'' though this need not preclude pile 
driving at night with sufficient illumination.
    Comment 6: The Commission recommends that NMFS continue to include 
in all draft and final incidental harassment authorizations, the 
explicit requirements to cease activities until NMFS reviews the 
circumstances involving any injury or death that has been attributed to 
the activity and determines what additional measures are necessary to 
minimize additional injuries or deaths.
    Response: NMFS concurs with the Commission's recommendation as it 
relates to this IHA and has added the referenced language to the 
Monitoring and Reporting section of this notice and the Reporting 
section of the issued IHA. We will continue to evaluate inclusion of 
this language in future IHAs.
    Comment 7: The Commission reiterates programmatic recommendations 
regarding NMFS' potential use of the renewal mechanism for one-year 
IHAs.
    Response: NMFS does not agree with the Commission and, therefore, 
does not adopt the Commission's recommendation. NMFS will provide a 
detailed explanation of its decision within 120 days, as required by 
section 202(d) of the MMPA.

Changes From the Proposed IHA to Final IHA

    The effective period for the final IHA is October 1, 2020 to 
February 28, 2021, rather than one year as described in the proposed 
IHA.
    Additionally, NMFS made several adjustments to the source levels 
included in the proposed IHA. The Commission informally noted that the 
reference distance for the impact pile driving source levels (Austin et 
al., 2016) should have been 11m, rather than the 10m used for 
calculations in the proposed IHA. NMFS agrees and has updated the Level 
A and Level B harassment zones to reflect the 11m reference distance. 
As informally noted by the Commission also, the peak source level for 
impact pile driving has been updated to 212.5dB, rather than 212dB. 
Also as recommended by the Commission, NMFS has reevaluated the impacts 
of DTH drilling, considering it to be an impulsive source for the 
purposes of calculating Level A harassment zones, rather than 
continuous as considered in the notice of proposed IHA. NMFS 
recalculated the Level A harassment zones using 166.2dB RMS SPL at 10m 
(Denes et al., 2016) and, accordingly, increased the authorized numbers 
of take by Level A harassment from five to seven for both harbor seal 
and harbor porpoise. Please see the Estimated Take section for the 
revised Level A harassment zones and final Level A harassment take 
authorizations.
    NMFS also made several changes to the take estimate included in the 
proposed IHA. As described further in the Estimated Take section, NMFS 
estimates that 2.2 percent of Steller sea lions in the project area are 
from the Western DPS, rather than the 3.1 percent estimated in the 
proposed authorization. Additionally, several take estimates were 
updated based on informal recommendations by the Commission. The harbor 
seal take estimate has been increased to 532 takes to reflect the 
latest Alaska Fisheries Science Center counts (August 2011) for the 
CE49 haul out sites, the minke whale take estimate has been increased 
from three to four individuals, and the killer whale take estimate has 
been increased from 24 to 32 animals.
    NMFS made several changes to the mitigation measures included in 
the proposed IHA (see Mitigation). The final IHA reflects an updated 
shutdown zone for low-frequency and high-frequency cetaceans during 
down-the-hole drilling (due to changes to the Level A harassment zones 
previously described) and during impact pile driving (due to changes to 
the Level A harassment zones resulting from the source level 
adjustments described above). The final IHA does not include the note 
that NMFS may adjust the shutdown zones pending review and approval of 
an acoustic monitoring report, as the applicant is not proposing to 
conduct hydroacoustic monitoring. Additionally, the final IHA reflects 
that during soft starts, the applicant will implement a one-minute 
waiting period, as described in the Federal Register notice for the 
proposed IHA, rather than a thirty-second waiting period as described 
in the proposed IHA itself. Finally, measure 4(e) of the final IHA 
states that after a shutdown has been implemented, pile driving may not 
commence or resume until either the animal has voluntarily left and 
been visually confirmed beyond the shutdown zone or 15 minutes have 
passed without subsequent detections, rather than 15 minutes for small 
cetaceans and pinnipeds and 30 minutes for large cetaceans, as 
described in the proposed IHA.
    Based on the Commission's recommendation, NMFS has also updated the 
reporting requirements for dead or injured marine mammals to require 
HPMS to cease the specified activities until NMFS notifies HPMS that 
they may resume.

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 (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS' 
website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species with expected potential for occurrence in 
Sitka, AK and summarizes information related to the population or 
stock, including regulatory status under the MMPA and ESA and potential 
biological removal (PBR), where known. For taxonomy, we follow 
Committee on Taxonomy (2019). PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS' 
SARs). While no mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For

[[Page 21402]]

some species, this geographic area may extend beyond U.S. waters. All 
managed stocks in this region are assessed in NMFS' U.S. 2018 SARs and 
draft 2019 SARs (e.g., Muto et al. 2019). All values presented in Table 
1 are the most recent available at the time of publication and are 
available in the 2018 and draft 2019 SARs (Muto et al., 2019 and 
Carretta et al., 2019).

                                              Table 1--Marine Mammals That Could Occur in 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 Eschrichtiidae:
    Gray whale......................  Eschrichtius robustus..  Eastern North Pacific..  -, -, N             26,960 (0.05, 25,849,         801        139
                                                                                                             2016).
Family Balaenidae:
    North Pacific Right Whale.......  Eubalaena japonica.....  Eastern North Pacific..  E, D, Y             31 (0.226, 26, 2015)..       0.05          0
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Central North Pacific..  -, -, Y             10,103 (0.300, 7,891,          83         26
                                                                                                             2006).
    Fin whale.......................  Balaenoptera physalus..  Northeast Pacific......  E, D, Y             see SAR (see SAR, see         5.1        0.4
                                                                                                             SAR, 2013).
    Minke whale.....................  Balaenoptera             Alaska.................  -, -, N             N/A (N/A, N/A, see            UND          0
                                       acutorostra.                                                          SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
    Sperm whale.....................  Physeter microcephalus.  North Pacific..........  E, D, Y             see SAR (see SAR, N/A,    see SAR        4.7
                                                                                                             2015).
Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Eastern North Pacific    -, -, N             2,347 (N/A, 2,347,             24          1
                                                                Alaska Resident.                             2012).
                                                               Gulf of Alaska,          -, -, N             587 (N/A, 587, 2012)..       5.87          1
                                                                Aleutian Islands,
                                                                Bearing Sea Transient.
                                                               Eastern North Pacific    -, -, N             302 c (N/A, 302, 2018)        2.2        0.2
                                                                Northern Resident.
                                                               West Coast Transient...  -, -, N             243 (N/A, 243, 2009)..        2.4          0
    Pacific white-sided dolphin.....  Lagenorhynchus           North Pacific..........  -, -, N             26,880 (UNK, UNK,             UND          0
                                       obliquidens.                                                          1990).
Family Phocoenidae (porpoises):
    Dall's porpoise.................  Phocoenoides dalli.....  Alaska.................  -, -, N             83,400 (0.097, NA,            UND         38
                                                                                                             1991).
    Harbor porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -, -, Y             see SAR (see SAR, see         8.9         34
                                                                                                             SAR, 2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    California sea lion.............  Zalophus californianus.  U.S....................  -, -, N             257,606 (N/A, 233,515,     14,011      >=321
                                                                                                             2014).
    Northern fur seal...............  Callorhinus ursinus....  Eastern Pacific........  -, D, Y             620,660 (0.2, 525,333,     11,295        399
                                                                                                             2016).
    Steller sea lion................  Eumetopias jubatus.....  Eastern................  -,-, N              43,201 a (see SAR,           2592        113
                                                                                                             43,201, 2017).
    Steller sea lion................  Eumetopias jubatus.....  Western................  E, D, Y             53,624 a (see SAR,            322        247
                                                                                                             53,624, 2018).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Sitka/Chatham Straight.  -, -, N             13,289 (see SAR,              356         77
                                                                                                             11,883, 2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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. In some cases, CV is not applicable [explain if this is the case]
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ These values are the best estimate of pup and non-pup counts which have not been corrected to account for animals at sea during abundance surveys.
Note--Italicized species are not expected to be taken or proposed for authorization.

    All species that could potentially occur in the project area are 
included in Table 1. However, the temporal and/or spatial occurrence of 
western north Pacific gray whales, northern right whale, fin whale, 
sperm whale, pacific white-sided dolphin, Dall's porpoise, California 
sea lion, and Northern fur seal is such that take is not expected to 
occur, and they are not discussed further beyond the explanation 
provided here.
    Marine mammal monitoring reports are available for three recent 
construction projects in the Sitka area (Gary Paxton Industrial Park 
Dock Modification Project, 82 FR 47717, October 13, 2017; Biorka Island 
Dock Replacement Project, 82 FR 50397, October 31, 2017; O'Connell 
Bridge Lightering Float Pile Replacement Project, 84 FR 27288, June 12, 
2019). These reports were referenced in determining marine mammals 
likely to be present within the Old Sitka Dock project area. NMFS 
acknowledges seasonal differences between the Old

[[Page 21403]]

Sitka Dock project and available monitoring reports.
    North Pacific Right Whale, fin whale, sperm whale, Dall's porpoise, 
and northern fur seal have not been reported in monitoring reports 
available for the recent Sitka-area, and were not observed during the 
Straley et al. (2017) surveys. Straley et al. (2017) only observed 
seven Pacific white-sided dolphins during eight years of surveys, 
however, no observations were reported in monitoring reports available 
for the recent Sitka-area. California sea lions are rarely sighted in 
southern Alaska. NMFS' anecdotal sighting database includes four 
sightings in Seward and Kachemak Bay, and they were also documented 
during the Apache 2012 seismic survey in Cook Inlet. However, 
California sea lions have not been reported in monitoring reports 
available for the recent Sitka-area construction projects.
    In addition, the northern sea otter may be found in Sitka. However, 
northern sea otters are managed by the U.S. Fish and Wildlife Service 
and are not considered further in this document.
    A detailed description of the of the species likely to be affected 
by the 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 (85 FR 
3623, January 22, 2020); since that time, we are not aware of any 
changes in the status of these species and stocks; therefore, detailed 
descriptions are not provided here. Please refer to that Federal 
Register notice for these descriptions. Please also refer to NMFS' 
website (https://www.fisheries.noaa.gov/find-species) for generalized 
species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    Underwater noise from impact and vibratory pile driving and down-
the-hole drilling activities associated with the Old Sitka Dock North 
Dolphins Expansion Project have the potential to result in harassment 
of marine mammals in the vicinity of the action area. The Federal 
Register notice for the proposed IHA (85 FR 3623, January 22, 2020) 
included a discussion of the potential effects of such disturbances on 
marine mammals and their habitat, therefore that information is not 
repeated in detail here; please refer to that Federal Register notice 
(85 FR 3623, January 22, 2020) for that information.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes are primarily by Level B harassment, as use of the 
acoustic sources (i.e. pile driving and removal, down-the-hole 
drilling) has the potential to result in disruption of behavioral 
patterns for individual marine mammals. There is also some potential 
for auditory injury (Level A harassment) to result, primarily for high 
frequency species and phocids because predicted auditory injury zones 
are larger than for mid-frequency species and otariids. Auditory injury 
is unlikely to occur for other species/groups. 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.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the take estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 microPascal ([mu]Pa) root mean square 
(rms) for continuous (e.g., vibratory pile-driving, drilling) and above 
160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., seismic 
airguns) or intermittent (e.g., scientific sonar) sources.
    For the purpose of Level B harassment zone calculation, HPMS's 
activity includes the use of continuous (vibratory pile driving and 
removal, down-the-hole drilling) 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 (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). HPMS's activity includes the use of 
impulsive (impact pile driving, down-the-hole drilling) and non-
impulsive (vibratory pile driving and removal) sources.

[[Page 21404]]

    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the project. Marine 
mammals are expected to be affected via sound generated by the primary 
components of the project (i.e., impact pile driving, vibratory pile 
driving and removal, down-the-hole drilling). The maximum (underwater) 
area ensonified above the thresholds for behavioral harassment 
referenced above is 55.9km\2\ (21.6mi\2\), and the calculated distance 
to the farthest behavioral harassment isopleth is approximately15.8km 
(9.8mi). Both are governed by landmasses in the Sound.
    The project includes vibratory and impact pile installation of 
steel pipe piles, vibratory removal of steel pipe piles, and down-the-
hole drilling. Source levels of pile installation and removal 
activities are based on reviews of measurements of the same or similar 
types and dimensions of piles available in the literature. Source 
levels for each pile size and activity are presented in Table 3. Source 
levels for vibratory installation and removal of piles of the same 
diameter are assumed to be the same.

                Table 3--Sound Source Levels for Pile Driving Methods and Down-the-Hole Drilling
----------------------------------------------------------------------------------------------------------------
                                                  Source level \a\
       Pile size and method       ------------------------------------------------       Literature source
                                       dB RMS        dB SEL \c\        dB peak
----------------------------------------------------------------------------------------------------------------
30-inch steel vibratory                 \b\ 168.0  ..............  ..............  Denes et al., 2016.
 installation/removal.
48-inch steel vibratory                 \b\ 168.0  ..............  ..............  Denes et al., 2016.
 installation.
33-inch drilled anchor shaft                166.2  ..............  ..............  Denes et al., 2016.
 (down-the-hole drilling) \e\.
48-inch steel impact installation           197.9           186.7           212.5  Austin et al., 2016.
 (and 30-inch steel impact
 installation, as necessary) \d\.
----------------------------------------------------------------------------------------------------------------
\a\ All source levels are referenced to 10m, except for impact pile driving which is referenced to 11m.
\b\ Source levels used for the impact analyses of vibratory installation/removal of 30-inch and 48-inch piles
  are the same. The most reasonable proxy source level for the 30-inch pile (including comparison of water depth
  and substrate) was 168.0 dB RMS, the median vibratory summary value from the Auke Bay site in Denes et al.
  (2016). For the 48-inch piles, NMFS determined that the median value from pile IP5 in Table 11 of Austin et
  al. (2016), 166.8 dB RMS, was the most appropriate proxy source level; however, this source level was lower
  than the proxy source level for the 30-inch pile. Typically, pile driving source levels are louder for
  installation/removal of larger piles. In effort to conduct a conservative analysis of the effects, NMFS
  adopted 168.0 dB RMS as a proxy source level for vibratory installation of the 48-inch piles as well.
\c\ Sound exposure level (dB re 1 [mu]Pa\2\-sec).
\d\ As previously noted, the applicant does not expect impact pile driving of the 30-inch piles to be necessary.
  However, if it is, the applicant will conservatively use source levels and Level A and Level B harassment zone
  calculations, and monitoring zones for impact pile driving of 48-inch steel piles.
\e\ As noted in the Changes from Proposed to Final section, the analysis of the applicant's DTH drilling
  activity considers sound produced as both a continuous and an impulsive noise source. NMFS has tentatively
  determined that Denes et al., 2016 provides the most appropriate source level for this analysis. However, this
  method is not intended to set precedent for future evaluation of DTH drilling as NMFS continues to analyze
  available data, and more data becomes available.


[[Page 21405]]

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

    TL = B * Log10 (R1/R2),

where

TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. Site-specific 
transmission loss data for Old Sitka Dock are not available, therefore 
the default coefficient of 15 is used to determine the distances to the 
Level A and Level B harassment thresholds.

               Table 4--Pile Driving Source Levels and Distances to Level B Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
                                                                      Level B
                                                   Source level    threshold (dB    Propagation     Distance to
              Pile size and method                 \a\ (dB re 1     re 1 [mu]Pa       (xLogR)         level B
                                                    [mu]Pa rms)        rms)                       threshold  (m)
----------------------------------------------------------------------------------------------------------------
30-inch steel vibratory installation/removal....       \b\ 168.0             120              15          15,849
48-inch steel vibratory installation............       \b\ 168.0             120              15          15,849
33-inch drilled anchor shaft (down-the-hole                166.2             120              15          12,023
 drilling)......................................
48-inch steel impact installation (and 30-inch             197.9             160              15           3,699
 steel impact installation, as necessary).......
----------------------------------------------------------------------------------------------------------------
\a\ All source levels are referenced to 10m, except for impact pile driving which is referenced to 11m.
\b\ As noted in Table 3, source levels for the 30-inch and 48-inch steel pipe piles are the same.

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources such as pile 
driving, NMFS User Spreadsheet predicts the distance at which, if a 
marine mammal remained at that distance the whole duration of the 
activity, it would incur PTS. Inputs used in the User Spreadsheet, and 
the resulting isopleths are reported below.

          Table 5--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
                                                                                   48-inch pile
                                                                                      impact
                                                   30-inch pile       33-inch      installation    48-inch pile
   Pile size and installation      48-inch pile      vibratory    drilled anchor   (and 30-inch       impact
             method                  vibratory     installation/   shaft (down-    steel impact    installation
                                   installation       removal        the-hole      installation,       (PK)
                                                                     drilling)     as necessary)
                                                                                     (SELcum)
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............  A.1) Vibratory  A.1) Vibratory   E) Impulsive-     E.1) Impact     E.1) Impact
                                    pile driving    pile driving      Stationary    pile driving    pile driving
Weighting Factor Adjustment                  2.5             2.5               2               2               2
 (kHz)..........................
Source Level....................    168.0 dB rms    168.0 dB rms    166.2 dB rms    186.7 dB SEL   212.5 dB peak
                                             SPL             SPL             SPL
Number of piles within 24-h                    2               2  ..............               2  ..............
 period.........................
Duration to drive a single pile               60              30  ..............  ..............  ..............
 (minutes)......................
Pulse Duration (seconds)........  ..............  ..............             0.1  ..............  ..............
1/Repetition Rate...............  ..............  ..............             0.1  ..............  ..............
Number of strikes per pile......  ..............  ..............  ..............             135  ..............
Activity Duration within 24-h     7200 (seconds)  3600 (seconds)    2 (hours)\a\  ..............  ..............
 period.........................
Propagation (xLogR).............              15              15              15              15  ..............
Distance from source level                    10              10              10              11              11
 measurement (meters)...........
----------------------------------------------------------------------------------------------------------------
\a\ The applicant estimates that DTH drilling work will last approximately eight hours in one day, with seven
  hours of active drilling. NMFS does not expect that an animal would remain in the area for seven hours.
  Rather, NMFS expects that an animal is likely to be exposed to a maximum of two hours of drilling noise, and
  as such, calculated the Level A harassment zones based on an activity duration of two hours within a 24-hour
  period.


[[Page 21406]]


                                              Table 6--Calculated Distances to Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Level A harassment zone (m)
                                                                  --------------------------------------------------------------------------------------
                             Activity                               Low-frequency    Mid-frequency     High-frequency        Phocid          Otariid
                                                                      cetaceans        cetaceans         cetaceans         pinnipeds        pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
30-inch Pile Vibratory Installation/Removal......................            20.0              1.8               29.6             12.2              0.9
48-inch Pile Vibratory Installation..............................            31.8              2.8               46.9             19.3              1.4
33-inch drilled anchor shaft (down-the-hole drilling)............           282.5             10.0              336.5            151.2             11.0
48-inch Pile Impact Installation (and 30-inch steel impact                  809.8             28.8              964.6            433.4             31.6
 installation, as necessary) (SELcum)............................
48-inch Pile Impact Installation (and 30-inch steel impact                    4.1   ...............              55.1              4.7   ...............
 installation, as necessary) (PK)................................
--------------------------------------------------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. We describe how the information provided above is brought 
together to produce a quantitative take estimate.
Gray Whale
    Straley et al., 2017 documented a group of three gray whales during 
surveys between 2002 and 2015, however, no gray whales were observed 
during monitoring for other recent construction projects in the area 
(CBS, 2019; Turnagain Marine Construction, 2017; Turnagain Marine 
Construction, 2018). NMFS estimates that one group of three gray whales 
may occur within the Level B harassment zone during construction (3 
animals x 1 group x 1 month = 3 Level B harassment takes) and 
therefore, authorized three Level B harassment takes of gray whales.
    The largest Level A harassment zone for low-frequency cetaceans 
extends 809.8m from the source during impact pile driving of 48-inch 
piles (or impact pile driving of 30-inch steel piles, as necessary) 
(Table 6). HPMS is planning to implement activity-specific shutdown 
zones (Table 8), which, especially in combination with the already low 
likelihood of gray whales entering the area, NMFS expects to eliminate 
the potential for Level A harassment take of gray whale. Therefore, 
Level A harassment takes of gray whale are not authorized.
Minke Whale
    Two minke whales were taken during the Biorka Island Dock 
Replacement project at the mouth of Sitka Sound (Turnagain Marine 
Construction, 2018). Based on monitoring data from Biorka Island, three 
Level B harassment takes of minke whale were authorized for the Sitka 
O'Connell Bridge project, however, no minke whale takes were reported. 
Both projects occurred in the month of June. Straley et al. (2017) did 
not report any observations of minke whales. However, because they were 
observed during the Biorka Island Dock Replacement project, NMFS 
estimated in the proposed authorization that one group of three minke 
whales may occur within the Level B harassment zone during the project, 
and therefore, planned to authorize three Level B harassment takes. 
However, based on informal correspondence with the Commission, NMFS is 
modifying the take authorization to include a Level B harassment take 
of one minke whale during each project week, as minke whales typically 
occur as individuals in Alaska (Dalheim et al., 2009; Navy, 2018). NMFS 
and the applicant originally considered the project a three-week 
project; however, the Commission informally recommended considering it 
a four-week project, as the contractor will likely work a five-day 
week. NMFS agrees with the Commission, and authorized four Level B 
harassment takes of minke whales.
    The largest Level A harassment zone for low-frequency cetaceans 
extends 809.8m from the source during impact pile driving of 48-inch 
piles (or impact pile driving of 30-inch steel piles, as necessary) 
(Table 6). HPMS will implement activity-specific shutdown zones (Table 
8), which, especially in combination with the already low likelihood of 
minke whales entering the area, are expected to eliminate the potential 
for Level A harassment take of minke whale. Therefore, takes of minke 
whale by Level A harassment were not requested, and are not authorized.
Humpback Whale
    Humpback whales frequent the action area and are likely to enter 
the Level B harassment zone during construction. Humpback whales 
typically occur in groups of two to four animals in the area (Straley 
et al., 2017). Given the large Level B harassment zone, HPMS estimated, 
and NMFS concurred, that four groups of two humpback whales may occur 
within the Level B harassment zone on each of the 19 days of in-water 
construction (2 animals in a group x 4 groups each day x 19 days = 152 
Level B harassment takes). Therefore, NMFS is authorizing 152 Level B 
harassment takes of humpback whales.
    For ESA Section 7 consultation purposes, NMFS estimates that 93.9 
percent of humpback whales in the project area are from the non-listed 
Hawaii DPS, and 6.1 percent of humpback whales in the project area are 
from the threatened Mexico DPS (Wade et al., 2016). Therefore, per 
guidance from the Alaska Region, of the 152 Level B harassment takes 
requested, 142 takes are expected to be of humpback whales from the 
Hawaii DPS and 10 takes are expected to be of humpbacks from the Mexico 
DPS.
    The largest Level A harassment zone for humpback whale extends 
809.8m from the source during impact pile driving of 48-inch piles 
(Table 6). HPMS will implement activity-specific shutdown zones (Table 
8), which, given the behavior and visibility of humpback whales, are 
expected to eliminate the potential for Level A harassment take of 
humpback whale. Therefore, takes of humpback whale by Level A 
harassment were not requested, and are not authorized.

Killer Whale

    Forty-four (44) killer whales were observed during 190 hours of 
observation from Whale Point between September and May from 1994 to 
2002 (Straley et al., 2017). Three killer whales were documented in 
Sitka Channel on one day in January 2017 during the Petro Marine Dock 
construction (Windward 2017). Seven killer whales were observed in 
June, but no killer whales were seen in July, August, or September in 
2018 at Biorka Island (Turnagain Marine Construction, 2018). No killer 
whales were observed in October or November 2017 on the western side of 
Eastern Channel or Silver Bay (Turnagain Marine Construction, 2017).

[[Page 21407]]

    During work on GPIP Dock, groups of five and 10 individuals were 
seen a few times, but, typically, single whales were observed near the 
mouth of Silver Bay (Turnagain Marine Construction, 2017). Straley et 
al.'s (2017) survey data indicates a typical killer whale group size 
between 4 and 8 individuals in Sitka Sound. Therefore, taking all of 
this information into consideration, NMFS proposed to authorize 24 
Level B harassment takes, expecting that one group of eight killer 
whales may enter the Level B harassment zone on each of three project 
weeks (8 animals in a group x 1 group per week x 3 weeks of activity = 
24 Level B harassment takes). However, as noted above, the Commission 
informally recommended considering the project a four-week project. 
NMFS agrees and is instead authorizing 32 Level B harassment takes (8 
animals in a group x 1 group per week x 4 weeks of activity). Killer 
whales from all four stocks listed in Table 1 have the potential to be 
taken by Level B harassment.
    The largest Level A harassment zone for mid-frequency cetaceans 
extends 28.8m from the source during impact installation of the 48-inch 
piles (or impact pile driving of 30-inch steel piles, as necessary) 
(Table 6). HPMS will implement activity-specific shutdown zones (Table 
8), which, given the small size of the zone and the visibility of 
killer whales, are expected to eliminate the potential for Level A 
harassment take of killer whale. Therefore, takes of killer whale by 
Level A harassment were not requested, and are not authorized.

Harbor Porpoise

    Harbor porpoises commonly frequent nearshore waters, but are not 
common in the project vicinity. Monthly tallies from observations from 
Sitka's Whale Park show harbor porpoises occurring infrequently in or 
near the action area in March, April, and October between 1994 to 2002 
(Straley et al., 2017). However, no harbor porpoises have been observed 
more recently during monitoring. No harbor porpoises were seen during 
the Petro Marine Dock construction monitoring in January 2017 
(Windward, 2017), during monitoring for the GPIP dock between October 
of November of 2017 (Turnagain Marine Construction, 2017), or during 
monitoring for the Sitka O'Connel Bridge project in 2019 (CBS, 2019). 
Halibut Point Marine Services staff indicated that they have not seen a 
harbor porpoise near the project site during the past 5 years (HPMS, 
2019).
    The mean group size of harbor porpoise in Southeast Alaska is 
estimated at two to three individuals (Dahlheim et al. 2009), however, 
Straley et al. (2017) found that typical group size in the project area 
is five animals. HPMS conservatively estimates, and NMFS concurs that 
one group of five harbor porpoises may enter the Level B harassment 
zone on each project day (5 animals in a group x 1 group per day x 19 
project days = 95 Level B harassment takes). Therefore, NMFS has 
authorized a total of 95 Level B harassment takes of harbor porpoise.
    Given the size of the Level A harassment zones for impact pile 
driving and DTH drilling and the relative expected frequency of harbor 
porpoises entering the zone, we are requiring a shutdown zone that is 
smaller than the area within which Level A harassment could occur in 
order to ensure that pile driving and DTH drilling are not interrupted 
to the degree that the activities are extended over additional days. 
Therefore, there is a small chance that Level A harassment could occur. 
NMFS authorized Level A harassment take of one harbor porpoise on each 
day that impact pile driving is expected occur (see Description of 
Proposed Activity in the Federal Register notice for the proposed IHA 
(85 FR 3623; January 22, 2020)). NMFS recognizes that HPMS may install 
the piles at a slightly slower rate resulting in more impact pile 
driving days; however, given the extremely short duration of impact 
pile driving on each pile, NMFS still does not expect that Level A 
harassment will exceed five takes during impact pile driving. NMFS also 
authorized Level A harassment take of one harbor porpoise on half of 
the days that the applicant expects to conduct DTH drilling, for a 
total of seven Level A harassment takes ((1 Level A harassment take x 5 
impact pile driving days) + (1 Level A harassment take x 2 DTH drilling 
days) = 7 Level A harassment takes). No Level A harassment takes of 
harbor porpoise were recorded in the Sitka GPIP Dock project (Turnagain 
Marine Construction, 2017) despite Level A harassment takes included in 
the authorizations. However, the Old Sitka Dock project has a longer 
work period and larger Level A harassment zones than the Sitka GPIP 
Dock project.

Harbor seal

    Harbor seals are common in the inside waters of southeastern 
Alaska, including in Sitka Sound and within the project action area. 
They were observed during most months of monitoring (September through 
May) from Whale Park between 1994 and 2002, except in December and May 
(Straley et al., 2017). Harbor seals were seen on 10 out of the 21 days 
of monitoring for GPIP dock construction between October and November 
2017, and two out of eight days of monitoring for the Petro Marine dock 
in January 2017 (Turnagain Marine Construction, 2017 and Windward 
2017).
    Straley et al.'s (2017) data indicate that a typical group size is 
between one and two harbor seals. Observations during the original 
construction of the Halibut Point Marine Services dock facility 
recorded zero harbor seals within the 200-meter shutdown zone during 
pile driving operations. Observers indicated only observing individual 
seals outside the 200-meter zone two to three times per week. (McGraw, 
pers. com., 2019).
    Harbor seals haul out of the water periodically to rest, give 
birth, and nurse their pups. According to the Alaska Fisheries Science 
Center's (AFSC) list of harbor seal haul-out locations, the closest 
listed haulout (id CE49) is located in Sitka Sound approximately 6.4 km 
(3.5 nmi) southwest, of the project site (AFSC, 2019).
    NMFS proposed to authorize 171 Level B harassment takes (3 animals 
in a group x 3 groups per day x 19 days = 171 Level B harassment 
takes), estimating that three groups of three harbor seals may enter 
the Level B harassment zone on each project day. However, as suggested 
by the Commission, NMFS contacted the AFSC regarding the haulout 
numbers at the CE49 haulouts, as these locations are in close proximity 
to the Level B harassment zone. AFSC advised that the current abundance 
estimate for the CE49 haulouts is 28 individuals from August 2011 (Erin 
Richmond, pers. comm., January 2020). As such, NMFS is instead 
authorizing 532 Level B harassment takes of harbor seals, estimating 
that each of the 28 seals at haulout CE49 is likely to enter the Level 
B harassment zone on each in-water work day (28 animals x 19 project 
days = 532 Level B harassment takes).
    Given the size of the zone and the relative expected frequency of 
harbor seals entering the zone, we are proposing a to require a 
shutdown zone that is smaller than the area within which Level A 
harassment could occur to ensure that pile driving and DTH drilling are 
not interrupted to the degree that the activities are extended over 
additional days. Therefore, there is a small chance that Level A 
harassment could occur. NMFS authorized Level A harassment take of one 
harbor seal on each day that impact pile driving is expected occur (see 
Description of Proposed Activity in the Federal

[[Page 21408]]

Register notice for the proposed IHA (85 FR 3623; January 22, 2020)) 
NMFS recognizes that HPMS may install the piles at a slightly slower 
rate resulting in more impact pile driving days; however, given the 
extremely short duration of impact pile driving on each pile, NMFS 
still does not expect that Level A harassment will exceed five takes 
during impact pile driving. Additionally, NMFS authorized Level A 
harassment take of one harbor seal on half of the four days that DTH 
drilling is expected to occur, for a total of seven Level A harassment 
takes ((1 Level A harassment take x 5 impact pile driving days) + (1 
Level A harassment take x 2 DTH drilling days) = 7 Level A harassment 
takes). No Level A harassment takes of harbor seal were recorded for 
either the Sitka O'Connell Bridge project (CBS, 2019), or the Sitka 
GPIP Dock project (Turnagain Marine Construction, 2017), however, the 
Old Sitka Dock project has a longer work period, and larger Level A 
harassment zones than the Sitka GPIP Dock project.

Steller Sea Lion

    Steller sea lions are common in the project area. They were 
observed during every month of monitoring (September to May) between 
1994 and 2002 (Straley et al., 2017). Steller sea lions were also 
observed on 19 of 21 days in Silver Bay and Easter Channel during 
monitoring for GPIP dock construction between October and November 2017 
(Turnagain Marine Construction, 2017). During eight days of monitoring 
for the Petro Marine dock in January 2017, Steller sea lions were seen 
on three days (Windward, 2017).
    During Straley et al.'s (2017) surveys, sea lions typically 
occurred in groups of two to three; however, a group of more than 100 
was sighted on at least one occasion. Steller sea lions in groups of 
one to eight individuals were observed around Sitka GPIP dock 
construction (Turnagain Marine Construction, 2017), while all Steller 
sea lions were observed individually in Sitka Channel during Petro 
Marine Dock construction monitoring (Windward, 2017). Observations 
during the original construction of the Halibut Point Marine Services 
dock facility recorded zero Steller sea lions within the 200-meter 
shutdown zone during pile driving operations. Observers indicated 
observing individual sea lions outside the 200-meter zone four to five 
times per week (McGraw, pers. comm., 2019).
    During the summer months, sea lions are seen in the project area 
daily. Two to three individual sea lions feed on fish carcasses dumped 
adjacent to the project site from fishing charter operations in a 
nearby private marina. However, during the project timing of fall and 
winter, the charter fishing operations are not underway and the sea 
lions are not as active in the area (McGraw, pers. comm., 2019).
    HPMS estimated, and NMFS concurred, that two groups of eight 
Steller sea lions (maximum group size observed during the Sitka GPIP 
dock construction (Turnagain Marine Construction, 2017)) may occur 
within the Level B harassment zone on each of the 19 days of in-water 
construction (8 animals in a group x 2 groups each day x 19 days = 304 
Level B harassment takes). Therefore, NMFS authorized 304 Level B 
harassment takes of Steller sea lions.
    The largest Level A harassment zone for otariids extends 28.7m from 
the source during impact pile driving of 48-inch piles (Table 6). HPMS 
is planning to implement activity-specific shutdown zones (Table 8), 
which, given the small size of the Level A harassment zones, are 
expected to eliminate the potential for Level A harassment take of 
Steller sea lion. Therefore, Level A harassment take of Steller sea 
lions was not requested, and is not authorized.
    Recognizing that western distinct population (WDPS) and eastern 
distinct population (EDPS) Steller sea lions overlap in northern 
Southeast Alaska, NMFS has determined that for management purposes the 
proportion of WDPS Steller sea lions in that area will be calculated 
based on Table 5 from Hastings et al. (2020) using the row for all non-
pups 1+ years old from the ``western stock region'' (i.e., the second 
row from the bottom in Table 5). Hastings et al. (2020) used mark/
recapture models, 18 years of resighting data from over 3,500 branded 
Steller sea lions, and mitochondrial DNA haplotypes from the WDPS and 
EDPS to estimate minimum proportions of Steller sea lions in regions 
within Southeast Alaska (east of 144[deg] W. longitude). As such, NMFS 
expects that 2.2 percent of Steller sea lions in the project area will 
be from the ESA-listed Western DPS, with the remaining 97.8 percent 
expected to be from the Eastern DPS. Therefore, of the 304 Level B 
harassment takes requested, 7 takes are expected to be of Steller sea 
lions from the ESA-listed Western DPS (western stock) and 297 are 
expected to be of Steller sea lions from the Eastern DPS (eastern 
stock).

                                     Table 7--Estimated Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Level A         Level B
                Common name                             Stock               harassment      harassment      Total take         Stock        Percent of
                                                                               take            take                          abundance         stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale................................  Eastern North Pacific.......               0               3               3          26,960            0.01
Minke Whale...............................  Alaska......................               0               4               4              NA              NA
Humpback Whale............................  Central North Pacific.......               0             152         \a\ 152          10,103             1.5
                                            Eastern North Pacific Alaska                                                           2,347             1.4
                                             Resident.
Killer Whale..............................  Gulf of Alaska, Aleutian                   0              32          32 \b\             587             5.5
                                             Islands, Bering Sea
                                             Transient.
                                            Eastern North Pacific                                                                    302            10.6
                                             Northern Resident.
                                            West Coast Transient........                                                             243            13.2
Harbor Porpoise...........................  Southeast Alaska............               7              95             102             975            10.5
Steller Sea Lion \c\......................  Eastern U.S.................               0             297             297          43,201             0.7
                                            Western U.S.................                               7               7          53,624            0.01
Harbor Seal...............................  Sitka/Chatham Strait........               7             532             539          13,289             4.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Of the authorized 152 Level B harassment takes, 142 takes are expected to be of humpback whales from the Hawaii DPS and 10 takes are expected to be
  of humpbacks from the Mexico DPS.
\b\ It is unknown what stock taken individuals may belong to. Therefore, for purposes of calculating the percent of each stock that may be taken, it is
  assumed that up to 24 takes could occur to individuals of any of the stocks that occur in the project area.
\c\ Eastern U.S. and Western U.S. stocks correspond to the Eastern DPS and Western DPS, respectively.


[[Page 21409]]

Mitigation Measures

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    In addition to the measures described later in this section, HPMS 
will employ the following standard mitigation measures:
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water heavy machinery work other than pile driving 
(e.g., standard barges, etc.), if a marine mammal comes within 10 m, 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions. This 
type of work could include the following activities: (1) Movement of 
the barge to the pile location; or (2) positioning of the pile on the 
substrate via a crane (i.e., stabbing the pile);
     HPMS will drive all piles with a vibratory hammer until 
achieving a desired depth or refusal prior to using an impact hammer;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal will shut 
down immediately if such species are observed within or on a path 
towards the Level B harassment zone; and
     If take reaches the authorized limit for an authorized 
species, pile installation will be shut down as these species approach 
the Level B harassment zone to avoid additional take.
    The following mitigation measures apply to HPMS's in-water 
construction activities.
    Additionally, HPMS is required to implement all mitigation measures 
described in the biological opinion (issued on April 2, 2020).
    Establishment of Shutdown Zones- HPMS will establish shutdown zones 
for all pile driving/removal and drilling activities. The purpose of a 
shutdown zone is generally to define an area within which shutdown of 
the activity will occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
will vary based on the activity type and marine mammal hearing group 
(see Table 8). The largest shutdown zones are generally for low 
frequency and high frequency cetaceans as shown in Table 8. For low-
frequency cetaceans, the shutdown zones contain the entire Level A 
harassment zones to help prevent Level A harassment takes, as the 
project area overlaps with humpback and gray whale BIAs.
    The placement of PSOs during all pile driving and removal and 
drilling activities (described in detail in the Monitoring and 
Reporting section) will ensure that the entire shutdown zone is visible 
during pile installation. Should environmental conditions deteriorate 
such that marine mammals within the entire shutdown zone will not be 
visible (e.g., fog, heavy rain), pile driving and removal must be 
delayed until the PSO is confident marine mammals within the shutdown 
zone could be detected.

            Table 8--Shutdown Zones During Pile Installation and Removal, and Down-the-Hole Drilling
----------------------------------------------------------------------------------------------------------------
                                                                 Shutdown zone (m)
            Activity             -------------------------------------------------------------------------------
                                   LF cetaceans    MF cetaceans    HF cetaceans       Phocids        Otariids
----------------------------------------------------------------------------------------------------------------
30-inch Vibratory Pile Driving/               50              10              50              25              10
 Removal........................
48-inch Vibratory Pile Driving..              50              10              50              25              10
Down-the-hole Drilling..........             300              10             200             100              25
48-inch Impact Pile Driving (and             825              50             100             100              50
 30-inch impact pile driving, as
 necessary).....................
----------------------------------------------------------------------------------------------------------------

    Monitoring for Level A and Level B Harassment--HPMS will monitor 
the Level B harassment zones (areas where SPLs are equal to or exceed 
the 160 dB rms threshold for impact driving and the 120 dB rms 
threshold during vibratory driving and drilling) and Level A harassment 
zones. Monitoring zones provide utility for observing by establishing 
monitoring protocols for areas adjacent to the shutdown zones. 
Monitoring zones enable observers to be aware of and communicate the 
presence of marine mammals in the project area outside the shutdown 
zone and thus prepare for a potential cease of activity should the 
animal enter the shutdown zone. Placement of PSOs on the shorelines 
around Sitka Channel allow PSOs to observe marine mammals within the 
Level A and Level B harassment zones. Due to the large Level B 
harassment zones (Table 4), PSOs will not be able to effectively 
observe the entire zone. Therefore, Level B harassment exposures will 
be recorded and extrapolated based upon the

[[Page 21410]]

number of observed takes and the percentage of the Level B harassment 
zone that was not visible.
    Soft Start--Soft-start procedures are believed to provide 
additional protection to marine mammals by providing warning and/or 
giving marine mammals a chance to leave the area prior to the hammer 
operating at full capacity. For impact pile driving, contractors will 
be required to provide an initial set of three strikes from the hammer 
at forty-percent energy, followed by a one-minute waiting period. This 
procedure will be conducted three times before impact pile driving 
begins. Soft start will be implemented at the start of each day's 
impact pile driving and at any time following cessation of impact pile 
driving for a period of thirty minutes or longer.
    Pre-activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal or 
drilling of 30 minutes or longer occurs, PSOs will observe the shutdown 
and monitoring zones for a period of 30 minutes. The shutdown zone will 
be considered cleared when a marine mammal has not been observed within 
the zone for that 30-minute period. If a marine mammal is observed 
within the shutdown zone, a soft-start cannot proceed until the animal 
has left the zone or has not been observed for 15 minutes. If the Level 
B harassment zone has been observed for 30 minutes and no species for 
which take is not authorized are present within the zone, soft start 
procedures can commence and work can continue even if visibility 
becomes impaired within the Level B harassment monitoring zone. When a 
marine mammal for which Level B harassment take is authorized is 
present in the Level B harassment zone, activities may begin and Level 
B harassment take will be recorded. If the entire Level B harassment 
zone is not visible at the start of construction, pile driving or 
drilling activities can begin. If work ceases for more than 30 minutes, 
the pre-activity monitoring of both the Level B harassment zone and 
shutdown zones will commence.
    Based on our evaluation of the applicant's measures, as well as 
other measures considered by NMFS, NMFS has preliminarily determined 
that these 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 
action area. Effective reporting is critical both to compliance as well 
as to ensuring that the most value is obtained from the required 
monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
Marine Mammal Monitoring Plan, dated March 2020. Marine mammal 
monitoring during pile driving and removal must be conducted by NMFS-
approved PSOs in a manner consistent with the following:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
     Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction;
     HPMS must submit PSO CVs for approval by NMFS prior to the 
onset of pile driving.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Three PSOs will be employed during all pile driving/removal and 
drilling activities. PSO locations will provide an unobstructed view of 
all water within the shutdown zone, and as much of the Level A and 
Level B harassment zones as possible. PSO locations are as follows:
    (1) At or near the site of pile driving;
    (2) Big Gavanski Island--During vibratory pile driving and down-
the-hole drilling, this PSO will be stationed on the north end of the 
island, and positioned to view north into Olga Straight and southeast 
toward the project area. For impact pile driving, this PSO will be 
stationed on the east side of the island, and positioned to be able to 
view north into Olga Straight and south toward the project area; and
    (3) Middle Island--During vibratory pile driving and down-the-hole 
drilling,

[[Page 21411]]

this PSO will be stationed on the north end of the island and 
positioned to be able to view west toward Kruzoff Island and east 
toward the project area. During impact pile driving, this PSO will be 
stationed on the east side of the island and positioned to view south 
toward Sitka Channel and east toward the project area.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal and drilling activities. In 
addition, observers shall record all incidents of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions in concert with distance from piles being 
driven or removed or anchor shafts being drilled. Pile driving and 
drilling activities include the time to install, remove, or drill 
inside a single pile or series of piles, as long as the time elapsed 
between uses of the pile driving or drilling equipment is no more than 
thirty minutes.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities. The report will include an overall description of work 
completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations;
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any.
     Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals.
     An extrapolation of the estimated takes by Level B 
harassment based on the number of observed exposures within the Level B 
harassment zone and the percentage of the Level B harassment zone that 
was not visible; and
     Other human activity in the area.
    If no comments are received from NMFS within 30 days, the draft 
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 event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder must 
immediately cease the specified activities and report the incident to 
the Office of Protected Resources (OPR) (301-427-8401), NMFS and to 
Alaska Regional Stranding Coordinator (907-586-7209) as soon as 
feasible. The report must include the following information:
    i. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    ii. Species identification (if known) or description of the 
animal(s) involved;
    iii. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    iv. Observed behaviors of the animal(s), if alive;
    v. If available, photographs or video footage of the animal(s); and
    vi. General circumstances under which the animal was discovered.
    NMFS will work with HPMS to determine what, if anything, is 
necessary to minimize the likelihood of further prohibited take and 
ensure MMPA compliance. HPMS must not resume their activities until 
notified by NMFS.

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).
    To avoid repetition, the majority of our analyses apply to all of 
the species listed in Table 7, given that many of the anticipated 
effects of this project on different marine mammal stocks are expected 
to be relatively similar in nature. Where there are meaningful 
differences between species or stocks in anticipated individual 
responses to activities, impact of expected take on the population due 
to differences in population status or impacts on habitat, they are 
described independently in the analysis below.
    Pile driving/removal and drilling activities associated with the 
project, as outlined previously, have the potential to disturb or 
displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level A and Level B harassment, from 
underwater sounds generated from pile driving/removal and down-the-hole 
drilling. Potential takes could occur if individuals of these species 
are present in zones ensonified above the thresholds for Level A or 
Level B harassment, identified above, when these activities are 
underway.
    The takes from Level A and Level B harassment will be due to 
potential behavioral disturbance, TTS and PTS. No mortality or serious 
injury is anticipated given the nature of the activity. Level A 
harassment is only anticipated for harbor seal and harbor porpoise. The 
potential for Level A harassment is minimized through the construction 
method and the implementation of the required mitigation measures (see 
Mitigation section).
    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

[[Page 21412]]

as increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006; HDR, Inc. 2012; Lerma 2014; ABR 2016). Most likely for pile 
driving and down-the-hole drilling, individuals will simply move away 
from the sound source and be temporarily displaced from the areas of 
pile driving and drilling, although even this reaction has been 
observed primarily only in association with impact pile driving. Level 
B harassment will be reduced to the level of least practicable adverse 
impact through use of mitigation measures described herein. If sound 
produced by project activities is sufficiently disturbing, animals are 
likely to simply avoid the area while the activity is occurring. While 
vibratory driving associated with the project may produce sound at 
distances of many kilometers from the project site, the project site 
itself is located in an active marine industrial area, as previously 
described. Therefore, we expect that animals annoyed by project sound 
will simply avoid the area and use more-preferred habitats, 
particularly as the project is expected to occur over just 19 in-water 
work days, with a maximum of eight hours of work per day, though less 
on most work days.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that harbor porpoises and harbor seals may 
sustain some limited Level A harassment in the form of auditory injury. 
However, animals that experience PTS will likely only receive slight 
PTS, i.e. minor degradation of hearing capabilities within regions of 
hearing that align most completely with the frequency range of the 
energy produced by pile driving, i.e. the low-frequency region below 2 
kHz, not severe hearing impairment or impairment in the regions of 
greatest hearing sensitivity. If hearing impairment occurs, it is most 
likely that the affected animal will lose a few decibels in its hearing 
sensitivity, which in most cases is not likely to meaningfully affect 
its ability to forage and communicate with conspecifics.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
will not modify existing marine mammal habitat for a significant amount 
of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and the relatively small area 
of the habitat that may be affected, the impacts to marine mammal 
habitat are not expected to cause significant or long-term negative 
consequences.
    Steller sea lion critical habitat has been defined in Southeast 
Alaska at major haulouts and major rookeries (50 CFR 226.202), however, 
the action area does not overlap with any Steller sea lion critical 
habitat. The closest Steller sea lion critical habitat to the project 
area is Kaiuchali Island, a three-acre rocky islet located slightly 
less than one mile southwest of Biorka Island. It is listed as ``Biorka 
Island'' in the critical habitat descriptions, and is over 25 km (13.5 
nmi) southwest of the project area.
    Critical habitat was recently proposed for the humpback whale in 
Southeast Alaska, including Sitka Sound (84 FR 54354, October 9, 2019), 
but it has not yet been finalized. Additionally, Sitka Sound is within 
the seasonal southeast Alaska humpback whale feeding BIA from March 
through November (Ferguson et al., 2015). Construction is expected to 
occur during the tail end of the season specified for the BIA; however, 
project activities will only overlap with the BIA for approximately one 
to two months, and the project is expected to occur over just 19 in-
water work days, further reducing the temporal overlap with the BIA. 
Additionally, the area of the BIA that may be affected by the planned 
project is small relative to both the overall area of the BIA and the 
overall area of suitable humpback whale habitat outside of this BIA. 
Therefore, take of humpback whales using the southeast Alaska humpback 
whale feeding BIA is not expected to impact reproduction or 
survivorship.
    Sitka Sound is also within a gray whale migratory corridor BIA 
(Ferguson et al., 2015). Construction is expected to occur during the 
beginning of the period of highest density in the BIA during the 
southbound migration (November to January). The Sound is also within 
the southeast Alaska BIA, an important area for gray whale feeding. 
Construction is expected to overlap with the end of the period with the 
highest gray whale densities in the southeast Alaska BIA (May through 
November). However, as noted for humpback whales, project activities 
will only overlap with high animal densities in the gray whale 
migratory and feeding BIAs for approximately one to two months, and the 
project is expected to occur over just 19 in-water workdays, further 
reducing the temporal overlap with the BIAs. Additionally, the area of 
the feeding BIA in which impacts of the planned project may occur is 
small relative to both the overall area of the BIA and the overall area 
of suitable gray whale habitat outside of this BIA. The area of Sitka 
Sound affected is also small relative to the rest of the Sound, such 
that it allows animals within the migratory corridor to still utilize 
Sitka Sound without necessarily being disturbed by the construction. 
Therefore, take of gray whales using the feeding and migratory BIAs is 
not expected to impact reproduction or survivorship.
    As noted previously, since January 1, 2019, elevated gray whale 
strandings have occurred along the west coast of North America from 
Mexico through Alaska. The event has been declared an UME, though a 
cause has not yet been determined. While three Level B harassment takes 
of gray whale are authorized, this is an extremely small portion of the 
stock (0.01 percent), and HPMS will be required to implement a shutdown 
zone that includes the entire Level A harassment zone for low-frequency 
cetaceans such as gray whales.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality or serious injury is anticipated or 
authorized;
     The relatively small number of Level A harassment 
exposures are anticipated to result only in slight PTS within the lower 
frequencies associated with pile driving;
     The anticipated incidents of Level B harassment will 
consist of, at worst, temporary modifications in behavior that will not 
result in fitness impacts to individuals;
     The area impacted by the specified activity is very small 
relative to the overall habitat ranges of all species, BIAs, and 
proposed humpback whale critical habitat; and
     The activity is expected to occur over 19 in-water 
workdays with a maximum of eight hours of work per day, though less on 
most days.
    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 sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other

[[Page 21413]]

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.
    The number of takes for each species authorized to be taken as a 
result of this project is included in Table 7. Our analysis shows that 
less than one-third of the best available population abundance estimate 
of each stock could be taken by harassment. Furthermore, these 
percentages conservatively assume that all takes of killer whale will 
be accrued to a single stock, when multiple stocks are known to occur 
in the project area. For the Alaska stock of minke whale, a lack of an 
accepted stock abundance value did not allow for the calculation of an 
expected percentage of the population that will be affected. The most 
relevant estimate of partial stock abundance is 1,233 minke whales for 
a portion of the Gulf of Alaska (Zerbini et al. 2006). Given three 
takes by Level B harassment for the stock, comparison to the best 
estimate of stock abundance shows less than one percent of the stock is 
expected to be impacted. The number of animals authorized to be taken 
for these stocks is considered small relative to the relevant stock's 
abundances even if each estimated taking occurred to a new individual, 
which is an unlikely scenario.
    Based on the analysis contained herein of the activity (including 
the mitigation and monitoring measures) and the anticipated take of 
marine mammals, NMFS finds that small numbers of marine mammals will be 
taken relative to the population size of the affected species or 
stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    The project is in an area where subsistence hunting for harbor 
seals or sea lions could occur (Wolfe et al. 2013). Peak hunting season 
in southeast Alaska occurs during the month of November and again 
during March and April. During this time, seals are aggregated in shoal 
areas as they prey on forage species such as herring, making them 
easier to find and hunt (Wolfe et al. 2013). However, the project 
location is not preferred for hunting. There is little-to-no hunting 
documented in the vicinity and there are no harvest quotas for non-
listed marine mammals. As such, the Old Sitka Dock North Dolphins 
Expansion Project is not expected to have impacts on the ability of 
hunters from southeast Alaska subsistence communities to harvest marine 
mammals. Additionally, HPMS contacted the Sitka Tribe of Alaska, but 
they did not raise any concerns regarding subsistence impacts. 
Therefore, NMFS has determined that there will not be an unmitigable 
adverse impact on subsistence uses from HPMS's activities.

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. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the Alaska Region, 
Protected Resources Division Office, whenever we propose to authorize 
take for endangered or threatened species.
    Two marine mammal species, Mexico DPS humpback whales and Western 
DPS Steller sea lions, occur in the project area and are listed as 
threatened and endangered, respectively, under the ESA. The NMFS Alaska 
Regional Office Protected Resources Division issued a Biological 
Opinion under section 7 of the ESA, on the issuance of an IHA to HPMS 
under section 101(a)(5)(D) of the MMPA by the NMFS Permits and 
Conservation Division. The Biological Opinion concluded that the action 
is not likely to jeopardize the continued existence of either species, 
and is not likely to destroy or adversely modify western DPS Steller 
sea lion critical habitat. As noted above, the proposed humpback whale 
critical habitat has not yet been finalized.

National Environmental Policy Act

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

Authorization

    NMFS has issued an IHA to Halibut Point Marine Services LLC for the 
potential harassment of small numbers of seven marine mammal species 
incidental to the Old Sitka Dock North Dolphins Expansion project in 
Sitka, Alaska, provided the previously mentioned mitigation, monitoring 
and reporting requirements are conducted.

    Dated: April 13, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-08085 Filed 4-16-20; 8:45 am]
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