[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
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI\3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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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).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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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).
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Order Carnivora--Superfamily Pinnipedia
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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).
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\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
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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.
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* 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]
BILLING CODE 3510-22-P