Notice2021-15046
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Geophysical Survey of the Queen Charlotte Fault
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
July 15, 2021
Effective
July 9, 2021
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to the Lamont-Doherty Earth Observatory of Columbia University (L-DEO) to incidentally harass marine mammals during a marine geophysical survey of the Queen Charlotte Fault in the Northeast Pacific Ocean.
Full Text
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<title>Federal Register, Volume 86 Issue 133 (Thursday, July 15, 2021)</title>
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[Federal Register Volume 86, Number 133 (Thursday, July 15, 2021)]
[Notices]
[Pages 37286-37309]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-15046]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XB223]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to a Geophysical Survey of the Queen
Charlotte Fault
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the Lamont-Doherty Earth Observatory of Columbia University (L-DEO) to
incidentally harass marine mammals
[[Page 37287]]
during a marine geophysical survey of the Queen Charlotte Fault in the
Northeast Pacific Ocean.
DATES: The authorization is effective for a period of one year, from
July 9, 2021, through July 8, 2022.
FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
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: <a href="http://www.fisheries.noaa.gov/action/incidental-take-authorization-lamont-doherty-earth-observatory-geophysical-survey-queen">www.fisheries.noaa.gov/action/incidental-take-authorization-lamont-doherty-earth-observatory-geophysical-survey-queen</a>. In case of problems accessing these documents, please call the
contact listed above.
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
Summary of Request
On December 3, 2019, NMFS received a request from L-DEO for an IHA
to take marine mammals incidental to a geophysical survey of the Queen
Charlotte Fault (QCF) off of Alaska and British Columbia, Canada. L-DEO
submitted a revised version of the application on April 2, 2020. On
April 10, 2020, L-DEO informed NMFS that the planned survey would be
deferred to 2021 as a result of issues related to the COVID-19
pandemic. L-DEO subsequently submitted revised versions of the
application on October 22 and December 16, 2020, the latter of which
was deemed adequate and complete. A final, revised version was
submitted on January 11, 2021. L-DEO's request is for take of 21
species of marine mammals by Level B harassment. In addition, NMFS
proposes to authorize take by Level A harassment for seven of these
species.
Description of Proposed Activity
Overview
Researchers from L-DEO, the University of New Mexico, and Western
Washington University, with funding from NSF, plan to conduct a high-
energy seismic survey from the Research Vessel (R/V) Marcus G. Langseth
(Langseth) at the QCF in the northeast Pacific Ocean during late summer
2021. Other research collaborators include Dalhousie University, the
Geological Survey of Canada, and the U.S. Geological Survey. The two-
dimensional (2-D) seismic survey will occur within the Exclusive
Economic Zones (EEZ) of the United States and Canada, including in
Canadian territorial waters. The survey will use a 36-airgun towed
array with a total discharge volume of ~6,600 cubic inches (in\3\) as
an acoustic source, acquiring return signals using both a towed
streamer as well as ocean bottom seismometers (OBSs).
The study will use 2-D seismic surveying to characterize crustal
and uppermost mantle velocity structure, fault zone architecture and
rheology, and seismicity of the QCF. The QCF system is an approximately
1,200 kilometer (km)-long onshore-offshore transform system connecting
the Cascadia and Alaska-Aleutian subduction zones; the QCF is the
approximately 900 km-long offshore component of the transform system.
The purpose of the study is to characterize an approximately 450-km
segment of the fault that encompasses systematic variations in key
parameters in space and time: (1) changes in fault obliquity relative
to Pacific-North American plate motion leading to increased convergence
from north to south; (2) Pacific plate age and theoretical mechanical
thickness decrease from north to south; and (3) a shift in Pacific
plate motion at approximately 12-6 million years ago that may have
increased convergence along the entire length of the fault, possibly
initiating underthrusting in the southern portion of the study area.
Current understanding of how these variations are expressed through
seismicity, crustal-scale deformation, and lithospheric structure and
dynamics is limited due to lack of instrumentation and modern seismic
imaging.
Dates and Duration
The survey is expected to last for approximately 36 days, including
approximately 27 days of seismic operations, 3 days of equipment
deployment/retrieval, 2 days of transits, and 4 contingency days
(accounting for potential delays due to, e.g., weather). R/V Langseth
will likely leave out of and return to port in Ketchikan, Alaska,
during July-August 2021.
Specific Geographic Region
The survey will occur within the area of approximately 52-57[deg] N
and approximately 131-137[deg] W. Representative survey tracklines are
shown in Figure 1. Some deviation in actual track lines, including the
order of survey operations, could be necessary for reasons such as
science drivers, poor data quality, inclement weather, or mechanical
issues with the research vessel and/or equipment. The survey will occur
within the EEZs of the United States and Canada, including Alaskan
state waters and Canadian territorial waters, ranging in depth from 50-
2,800 meters (m). Approximately 4,250 km of transect lines will be
surveyed, with 13 percent of the transect lines in Canadian territorial
waters. Most of the survey (69 percent) will occur in deep water
(>1,000 m), 30 percent will occur in intermediate water (100-1,000 m
deep), and approximately 1 percent will take place in shallow water
<100 m deep.
Note that the MMPA does not apply in Canadian territorial waters.
L-DEO is subject only to Canadian law in conducting that portion of the
survey. However, NMFS has calculated the expected level of incidental
take in the entire activity area (including Canadian territorial
waters) as part of the analysis supporting our determination under the
MMPA that the activity will have a negligible impact on the affected
species (see Estimated Take and Negligible Impact Analysis and
Determination).
BILLING CODE 3510-22-P
[[Page 37288]]
[GRAPHIC] [TIFF OMITTED] TN15JY21.104
[[Page 37289]]
BILLING CODE 3510-22-C
Detailed Description of Specific Activity
The procedures to be used for the survey will be similar to those
used during previous seismic surveys by L-DEO and will use conventional
seismic methodology. The survey will involve one source vessel, the R/V
Langseth. R/V Langseth will deploy an array of 36 airguns as an energy
source with a total volume of 6,600 cubic inches (in\3\). The array
consists of 36 elements, including 20 Bolt 1500LL airguns with volumes
of 180 to 360 in\3\ and 16 Bolt 1900LLX airguns with volumes of 40 to
120 in\3\. The airgun array configuration is illustrated in Figure 2-11
of NSF and USGS's Programmatic Environmental Impact Statement (PEIS;
NSF-USGS, 2011). (The PEIS is available online at: <a href="http://www.nsf.gov/geo/oce/envcomp/usgs-nsf-marine-seismic-research/nsf-usgs-final-eis-oeis-with-appendices.pdf">www.nsf.gov/geo/oce/envcomp/usgs-nsf-marine-seismic-research/nsf-usgs-final-eis-oeis-with-appendices.pdf</a>). The vessel speed during seismic operations will be
approximately 4.2 knots (kn) (~7.8 km/hour) during the survey and the
airgun array will be towed at a depth of 12 m. The receiving system
will consist of OBSs and a towed hydrophone streamer with a nominal
length of 15 km (OBS and multi-channel seismic (MCS) shooting). As the
airguns are towed along the survey lines, the hydrophone streamer will
transfer the data to the on-board processing system, and the OBSs will
receive and store the returning acoustic signals internally for later
analysis.
Approximately 60 short-period OBSs will be deployed and
subsequently retrieved at a total of 123 sites in multiple phases from
a second vessel, the Canadian Coast Guard ship John P. Tully (CCGS
Tully). Along OBS refraction lines, OBSs will be deployed by CCGS Tully
at 10 km intervals, with a spacing of 5 km over the central 40 km of
the fault zone for fault-normal crossings. Twenty-eight broadband OBS
instruments will also collect data during the survey and will be
deployed prior to the active-source seismic survey, depending on
logistical constraints. When an OBS is ready to be retrieved, an
acoustic release transponder (pinger) interrogates the instrument at a
frequency of 8-11 kilohertz (kHz); a response is received at 11.5-13
kHz. The burn-wire release assembly is then activated, and the
instrument is released from its 80-kg anchor to float to the surface.
Take of marine mammals is not expected to occur incidental to L-DEO's
use of OBSs.
The airguns will fire at a shot interval of 50 m (approximately 23
seconds (s)) during MCS shooting with the hydrophone streamer
(approximately 42 percent of survey effort), at a 150-m interval
(approximately 69 s) during refraction surveying to OBSs (approximately
29 percent of survey effort), and at a shot interval of every minute
(approximately 130 m) during turns (approximately 29 percent of survey
effort).
Short-period OBSs will be deployed first along five OBS refraction
lines by CCGS Tully. Two OBS lines run parallel to the coast, and three
are perpendicular to the coast; one perpendicular line is located off
Southeast Alaska, one is off Haida Gwaii, British Columbia, and another
is located in Dixon Entrance. Please see Figure 1 for all location
references. Following refraction shooting of a single line, short-
period instruments on that line will be recovered, serviced, and
redeployed on a subsequent refraction line while MCS data will be
acquired by the Langseth. MCS lines will be acquired off Southeast
Alaska, Haida Gwaii, and Dixon Entrance. The coast-parallel OBS
refraction transect nearest to shore will only be surveyed once at OBS
shot spacing. The other coast-parallel OBS refraction transect (on the
ocean side) will be acquired twice, once during refraction and once
during reflection surveys. In addition, portions of the three coast-
perpendicular OBS refraction lines will also be surveyed twice, once
for OBS shot spacing and once for MCS shot spacing. The coincident
reflection/refraction profiles that run parallel to the coast will be
acquired in multiple segments to ensure straight-line geometry.
Sawtooth transits during which seismic data will be acquired will take
place between transect lines when possible; otherwise, boxcar turns
will be performed to save time. Both reflection and refraction surveys
will use the same airgun array with the same discharge volume. There
could be additional seismic operations associated with turns, airgun
testing, and repeat coverage of any areas where initial data quality is
sub-standard, and 25 percent has been added to the assumed survey line-
kms to account for this potential.
In addition to the operations of the airgun array, a multibeam
echosounder (MBES), a sub-bottom profiler (SBP), and an Acoustic
Doppler Current Profiler (ADCP) will be operated from R/V Langseth
continuously during the seismic surveys, but not during transit to and
from the survey area. Take of marine mammals is not expected to occur
incidental to use of the MBES, SBP, or ADCP because they will be
operated only during seismic acquisition, and it is assumed that,
during simultaneous operations of the airgun array and the other
sources, any marine mammals close enough to be affected by the MBES,
SBP, and ADCP would already be affected by the airguns. However,
whether or not the airguns are operating simultaneously with the other
sources, given the other sources' characteristics (e.g., narrow
downward-directed beam), marine mammals would experience no more than
one or two brief ping exposures from them, if any exposure were to
occur. No take of marine mammals is expected to occur incidental to the
use of these sources, regardless of whether they are used in
conjunction with the airgun array. Required mitigation, monitoring, and
reporting measures are described in detail later in this document
(please see Mitigation and Monitoring and Reporting).
Comments and Responses
A notice of proposed IHA was published in the Federal Register on
June 4, 2021 (86 FR 30006). During the 30-day public comment period,
NMFS did not receive any substantive public comments.
Changes From the Proposed IHA
The primary change from the proposed IHA is the addition of take
authorization for the North Pacific right whale. In the notice of
proposed IHA, we described available information regarding North
Pacific right whale occurrence in the survey region and determined that
encounter was unlikely and that authorization of take was not
warranted. Following publication of the notice of proposed IHA, on
approximately June 15, 2021, a North Pacific right whale was observed
in Canadian waters off Haida Gwaii during survey effort by the
Department of Fisheries and Oceans Canada (Kloster, 2021). As a result,
NMFS has authorized North Pacific right whale take, as described in
greater detail in Estimated Take, given the potential for a repeat
encounter during L-DEO's survey.
In addition, we rectify an error in the estimated take of Steller
sea lions occurring within Canadian territorial waters. Estimates of
take that may occur within foreign territorial waters are not
authorized under the MMPA, but are considered in making a finding of
negligible impact on the affected species or stocks. In this case, we
incorrectly applied a density value to L-DEO survey effort in deep
water, when in fact the density of Steller sea lions in the deep depth
stratum is correctly assumed to be zero (DoN, 2021). Through correction
of this error, the estimated take of Steller sea lions in Canadian
[[Page 37290]]
territorial waters is revised from 2,522 to 2,278. Please see Table 7.
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' Stock Assessment Reports (SARs; <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website
(<a href="http://www.fisheries.noaa.gov/find-species">www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species with expected potential for occurrence in
the survey area and summarizes information related to the population or
stock, including regulatory status under the MMPA and Endangered
Species Act (ESA) and potential biological removal (PBR), where known.
For taxonomy, we follow Committee on Taxonomy (2021). PBR is defined by
the MMPA as the maximum number of animals, not including natural
mortalities, that may be removed from a marine mammal stock while
allowing that stock to reach or maintain its optimum sustainable
population (as described in NMFS's SARs). While no mortality is
anticipated or authorized here, PBR and annual serious injury and
mortality from anthropogenic sources are included here as gross
indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Pacific and Alaska SARs. All MMPA stock information
presented in Table 1 is the most recent available at the time of
publication and is available in the 2019 SARs (Caretta et al., 2020;
Muto et al., 2020) and draft 2020 SARs (available online at:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports">www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports</a>). Where available, abundance and status
information is also presented for marine mammals in British Columbia
waters. Twenty-two species (with 29 managed stocks) are considered to
have the potential to occur in the survey area.
Table 1--Marine Mammals That Could Occur in the Survey Area
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ESA/MMPA Stock abundance
status; (CV, Nmin, most British Annual M/
Common name Scientific name Stock strategic (Y/ recent abundance Columbia PBR SI \4\
N) \1\ survey) \2\ abundance \3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenidae:
North Pacific right whale.... Eubalaena japonica.. Eastern North E/D; Y 31 (0.226; 26; .............. 0.05 0
Pacific (ENP). 2008).
Family Eschrichtiidae:
Gray whale................... Eschrichtius Eastern North -; N 26,960 (0.05; .............. 801 131
robustus. Pacific (ENP) *. 25,849; 2016).
Western North E/D; Y 290 (n/a; 271; .............. 0.12 Unk
Pacific (WNP)*. 2016).
Family Balaenopteridae
(rorquals):
Humpback whale............... Megaptera Central North E/D; Y 10,103 (0.3; 7,891; 1,029 83 26
novaeangliae kuzira. Pacific (CNP) *. 2006).
Minke whale.................. Balaenoptera Alaska *............ -; N Unknown............ 522 Undet. 0
acutorostrata
scammoni.
Sei whale.................... B. borealis borealis ENP................. E/D; Y 519 (0.4; 374; .............. 0.75 >=0.2
2014).
Fin whale.................... B. physalus physalus Northeast Pacific *. E/D; Y Unknown............ 329 Undet. 0.6
Blue whale................... B. musculus musculus ENP................. E/D; Y 1,496 (0.44; 1,050; .............. \7\ 1.2 >=19.4
2014).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Physeteridae:
Sperm whale.................. Physeter North Pacific *..... E/D; Y Unknown............ .............. Undet. 3.5
macrocephalus.
Family Ziphiidae (beaked whales):
Cuvier's beaked whale........ Ziphius cavirostris. Alaska *............ -; N Unknown............ .............. Undet. 0
Baird's beaked whale......... Berardius bairdii... Alaska *............ -; N Unknown............ .............. Undet. 0
Stejneger's beaked whale..... Mesoplodon Alaska *............ -; N Unknown............ .............. Undet. 0
stejnegeri.
Family Delphinidae:
Pacific white-sided dolphin.. Lagenorhynchus North Pacific \6\... -; N 26,880 (n/a; 22,160 Undet. 0
obliquidens. 26,880; 1990).
Northern right whale dolphin. Lissodelphis CA/OR/WA............ -; N 26,556 (0.44; .............. 179 3.8
borealis. 18,608; 2014).
Risso's dolphin.............. Grampus griseus..... CA/OR/WA............ -; N 6,336 (0.32; 4,817; .............. 46 >=3.7
2014).
Killer whale................. Orcinus orca \5\.... ENP Offshore........ -; N 300 (0.1; 276; 371 2.8 0
2012).
ENP Gulf of Alaska, -; N 587 (n/a; 2012).... 5.9 0.8
Aleutian Islands,
and Bering Sea
Transient.
ENP West Coast -; N 349 (n/a; 2018).... 3.5 0.4
Transient.
ENP Alaska Resident. -; N 2,347 (n/a; 2012).. 24 1
Northern Resident... -; N 302 (n/a; 2018).... 2.2 0.2
[[Page 37291]]
Family Phocoenidae (porpoises):
Harbor porpoise.............. Phocoena phocoena Southeast Alaska *.. -; Y Unknown............ 8,091 Undet. 34
vomerina.
Dall's porpoise.............. Phocoenoides dalli Alaska \6\.......... -; N 83,400 (0.097; n/a; 5,303 Undet. 38
dalli. 1991).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Northern fur seal............ Callorhinus ursinus. Pribilof Islands/ D; Y 608,143 (0.2; .............. 11,067 387
Eastern Pacific. 514,738; 2018).
California sea lion.......... Zalophus United States....... -/-; N 257,606 (N/A, .............. 14,011 >=321
californianus. 233,515, 2014).
Steller sea lion............. Eumetopias jubatus Western U.S. *...... E/D; Y 52,932 (n/a; 2019). 15,348 318 255
jubatus.
E. j. monteriensis.. Eastern U.S. *...... -/-; N 43,201 (n/a; 2017). .............. 2,592 112
Family Phocidae (earless seals):
Harbor seal.................. Phoca vitulina Sitka/Chatham Strait -; N 13,289 (n/a; 24,916 356 77
richardii. 11,883; 2015).
Dixon/Cape Decision. -; N 23,478 (n/a; 644 69
21,453; 2015).
Clarence Strait..... -; N 27,659 (n/a; 746 40
24,854; 2015).
Northern elephant seal....... Mirounga California Breeding. -; N 179,000 (n/a; .............. 4,882 8.8
angustirostris. 81,368; 2010).
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*Stocks marked with an asterisk were addressed in further detail in the notice of proposed IHA (86 FR 30006; June 4, 2021).
\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 at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>. CV is
coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For most stocks of killer whales, the
abundance values represent direct counts of individually identifiable animals; therefore there is only a single abundance estimate with no associated
CV. For certain stocks of pinnipeds, abundance estimates are based upon observations of animals (often pups) ashore multiplied by some correction
factor derived from knowledge of the species' (or similar species') life history to arrive at a best abundance estimate; therefore, there is no
associated CV. In these cases, the minimum abundance may represent actual counts of all animals ashore.
\3\ Total abundance estimates for animals in British Columbia based on surveys of the Strait of Georgia, Johnstone Strait, Queen Charlotte Sound, Hecate
Strait, and Dixon Entrance. This column represents estimated abundance of animals in British Columbia, where available, but does not necessarily
represent additional stocks. Please see Best et al. (2015) and Pitcher et al. (2007) for additional information.
\4\ 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, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum
value. All M/SI values are as presented in the draft 2020 SARs.
\5\ Transient and resident killer whales are considered unnamed subspecies (Committee on Taxonomy, 2020).
\6\ Abundance estimates for these stocks are not considered current. PBR is therefore considered undetermined for these stocks, as there is no current
minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as these represent the best available
information for use in this document.
\7\ This stock is known to spend a portion of time outside the U.S. EEZ. Therefore, the PBR presented here is the allocation for U.S. waters only and is
a portion of the total. The total PBR for blue whales is 2.1 (7/12 allocation for U.S. waters). Annual M/SI presented for these species is for U.S.
waters only.
Table 1 denotes the status of species and stocks under the U.S.
MMPA and ESA. We note also that under Canada's Species at Risk Act, the
sei whale and blue whale are listed as endangered; the fin whale and
northern resident, offshore, and transient populations of killer whales
are listed as threatened; and the humpback whale, harbor porpoise, and
Steller sea lion are considered species of special concern.
The North Pacific right whale historically occurred across the
North Pacific Ocean in subpolar to temperate waters, including waters
off the coast of British Columbia (Scarff, 1986; Clapham et al., 2004).
Sightings of this endangered species are now extremely rare, occurring
primarily in the Okhotsk Sea and the eastern Bering Sea (Brownell et
al., 2001; Shelden et al., 2005; Wade et al., 2006; Zerbini et al.,
2010). The summer range of the eastern North Pacific stock includes the
Gulf of Alaska (GOA) and the Bering Sea, while the winter calving
grounds remain unknown. Sightings in GOA are extremely rare. During
three separate marine mammal surveys in the northern GOA from 2013-
2019, including one dedicated to right whales, right whales were
acoustically detected off Kodiak Island but were not visually observed
(Muto et al., 2020).
In 2013, two North Pacific right whale sightings were made off the
coast of British Columbia (U.S. Department of the Navy, 2015),
representing the first sightings in Canadian waters since the 1950s.
Individual sightings in Canadian waters were subsequently recorded in
2018 and 2020 (Muto et al., 2020). There have also been four sightings,
each of a single North Pacific right whale, in California waters within
approximately the last 30 years (most recently in 2017) (Carretta et
al., 1994; Brownell et al., 2001; Price, 2017). This historical paucity
of sightings in the region led NMFS to conclude that there would be a
very low probability of encountering this species in the action area
and, therefore, that take should not be proposed for authorization.
However, following the June 2021 sighting of a single right whale in
Canadian waters discussed above, we have determined that an encounter
could occur and, therefore, that take should be authorized. This
sighting, and the subsequent decision to authorize take, is not
necessarily inconsistent with the analysis presented in the notice of
[[Page 37292]]
proposed authorization. Rather, this sighting is consistent with the
recent historical record of infrequent, unpredictable occurrence in the
region. The fact that this most recent sighting has occurred within the
survey area and nearly contemporaneous with the planned survey means
that there is some heightened potential for encounter that should be
considered in authorizing take that may occur incidental to the survey
activity. See Estimated Take for additional discussion.
Two populations of gray whales are recognized, eastern and western
North Pacific (ENP and WNP). WNP whales are known to feed in the
Okhotsk Sea and off of Kamchatka before migrating south to poorly known
wintering grounds, possibly in the South China Sea. The two populations
have historically been considered geographically isolated from each
other; however, data from satellite-tracked whales indicate that there
is some overlap between the stocks. Two WNP whales were tracked from
Russian foraging areas along the Pacific rim to Baja California (Mate
et al., 2011), and, in one case where the satellite tag remained
attached to the whale for a longer period, a WNP whale was tracked from
Russia to Mexico and back again (IWC, 2012). A number of whales are
known to have occurred in the eastern Pacific through comparisons of
ENP and WNP photo-identification catalogs (IWC, 2012; Weller et al.,
2011; Burdin et al., 2011). Therefore, a portion of the WNP population
is assumed to migrate, at least in some years, to the eastern Pacific
during the winter breeding season. Based on guidance provided through
interagency consultation under section 7 of the ESA, approximately 0.1
percent of gray whales occurring in southeast Alaska and northern
British Columbia are likely to be from the Western North Pacific stock;
the rest would be from the Eastern North Pacific stock.
Prior to 2016, humpback whales were listed under the ESA as an
endangered species worldwide. Following a 2015 global status review
(Bettridge et al., 2015), NMFS delineated 14 distinct population
segments (DPS) with different listing statuses (81 FR 62259; September
8, 2016) pursuant to the ESA. The DPSs that occur in U.S. waters do not
necessarily equate to the existing stocks designated under the MMPA and
shown in Table 1.
In the eastern North Pacific, three humpback whale DPSs may occur:
the Hawaii DPS (not listed), Mexico DPS (threatened), and Central
America DPS (endangered). Individuals encountered in the proposed
survey area would likely be from the Hawaii DPS, followed by the Mexico
DPS; individuals from the Central America DPS are unlikely to feed in
northern British Columbia and Southeast Alaska (Ford et al., 2014).
According to Wade (2017), in southeast Alaska and northern British
Columbia, encountered whales are most likely to be from the Hawaii DPS
(96.1 percent), but could be from the Mexico DPS (3.8 percent).
Additional detailed information regarding the potentially affected
stocks of marine mammals was provided in the notice of proposed IHA (86
FR 30006; June 4, 2021). No new information is available, and we do not
reprint that discussion here. Please see the notice of proposed IHA for
additional information.
Important Habitat
Several biologically important areas (BIA) for marine mammals are
recognized in southeast Alaska, and critical habitat is designated in
southeast Alaska for the Steller sea lion (58 FR 45269; August 27,
1993) and the Mexico DPS of humpback whale (86 FR 21082; April 21,
2021). Note that although the eastern DPS of Steller sea lion was
delisted in 2013, the change in listing status does not affect the
designated critical habitat. Critical habitat is defined by section 3
of the ESA as (1) the specific areas within the geographical area
occupied by the species, at the time it is listed, on which are found
those physical or biological features (a) essential to the conservation
of the species and (b) which may require special management
considerations or protection; and (2) specific areas outside the
geographical area occupied by the species at the time it is listed,
upon a determination by the Secretary that such areas are essential for
the conservation of the species.
Mexico DPS humpback whale critical habitat includes marine waters
in Washington, Oregon, California, and Alaska. Only the areas
designated in southeast Alaska fall within the survey area. The
relevant designated critical habitat (Unit 10) extends from 139[deg]24'
W, southeastward to the U.S. border with Canada. The area also extends
offshore to a boundary drawn along the 2,000-m isobath. The essential
feature for Mexico DPS humpback whale critical habitat is prey species,
primarily euphausiids and small pelagic schooling fishes of sufficient
quality, abundance, and accessibility within humpback whale feeding
areas to support feeding and population growth. This area was drawn to
encompass well-established feeding grounds in southeast Alaska and an
identified feeding BIA (86 FR 21082; April 21, 2021). Humpback whales
occur year-round in this unit, with highest densities occurring in
summer and fall (Baker et al., 1985, 1986).
Critical habitat for humpback whales has been designated under
Canadian law in four locations in British Columbia (DFO, 2013),
including in the waters of the survey area off Haida Gwaii (Langara
Island and Southeast Moresby Island). These areas show persistent
aggregations of humpback whales and have features such as prey
availability, suitable acoustic environment, water quality, and
physical space that allow for feeding, foraging, socializing, and
resting (DFO, 2013).
Designated Steller sea lion critical habitat includes terrestrial,
aquatic, and air zones that extend 3,000 ft (0.9 km) landward, seaward,
and above each major rookery and major haul-out in Alaska. Within the
survey area, critical habitat is located on islands off the coast of
southeast Alaska (e.g., Sitka, Coronation Island, Noyes Island, and
Forrester Island). The physical and biological features identified for
the aquatic areas of Steller sea lion designated critical habitat that
occur within the survey area are those that support foraging, such as
adequate prey resources and available foraging habitat. The proposed
survey tracklines do not directly overlap any areas of Steller sea lion
critical habitat, though the extent of the estimated ensonified area
associated with the survey would overlap with units of Steller sea lion
critical habitat. However, the brief duration of ensonification for any
critical habitat unit leads us to conclude that any impacts on Steller
sea lion habitat would be insignificant and would not affect the
conservation value of the critical habitat.
For humpback whales, seasonal feeding BIAs for spring (March-May),
summer (June-August), and fall (September-November) are recognized in
southeast Alaska (Ferguson et al., 2015). It should be noted that the
aforementioned designated critical habitat in the survey area was based
in large part on the same information that informed an understanding of
the BIAs. Though the BIAs are not synonymous with critical habitat
designated under the ESA, they were regarded by the humpback whale
critical habitat review team as an important source of information and
informative to their review of areas that meet the definition of
critical habitat for humpback whales (86 FR 21082; April 21, 2021). The
aforementioned southeast Alaska unit of designated critical habitat
encompasses the BIAs, with the offshore and
[[Page 37293]]
nearshore boundaries corresponding with the BIA boundary.
A separate feeding BIA is recognized in southeast Alaska for gray
whales. Once considered only a migratory pathway, the Gulf of Alaska is
now known to provide foraging and overwintering habitat for ENP gray
whales (Ferguson et al., 2015). Based on the regular occurrence of
feeding gray whales (including repeat sightings of individuals across
years) off southeast Alaska, an area off of Sitka is recognized. The
greatest densities of gray whales on the feeding area in southeast
Alaska occur from May to November. However, this area is located to the
north of the proposed survey area and would not be expected to be
meaningfully impacted by the survey activities. A separate migratory
BIA is recognized as extending along the continental shelf throughout
the Gulf of Alaska. During their annual migration, most gray whales
pass through the Gulf of Alaska in the fall (November through January;
southbound) and again in the spring (March through May; northbound)
(Ferguson et al., 2015). Therefore, the planned survey would not be
expected to impact gray whale migratory habitat due to the timing of
the survey in late summer. No important behaviors of gray whales in
either the feeding or migratory BIAs are expected to be affected. For
more information on BIAs, please see Ferguson et al. (2015) or visit
<a href="https://oceannoise.noaa.gov/biologically-important-areas">https://oceannoise.noaa.gov/biologically-important-areas</a>.
Unusual Mortality Events (UME)
A UME is defined under the MMPA as ``a stranding that is
unexpected; involves a significant die-off of any marine mammal
population; and demands immediate response.'' For more information on
UMEs, please visit: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-unusual-mortality-events">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-unusual-mortality-events</a>. There is a currently
ongoing UME affecting gray whales throughout their migratory range.
Since January 1, 2019, elevated gray whale strandings have occurred
along the west coast of North America from Mexico through Alaska. As of
July 1, 2021, there have been a total of 480 whales reported in the
event, with approximately 225 dead whales in Mexico, 237 whales in the
United States (70 in California; 11 in Oregon; 55 in Washington, 101 in
Alaska), and 18 whales in British Columbia, Canada. For the United
States, the historical 18-year 5-month average (Jan-May) is 14.8 whales
for the four states for this same time-period. Several dead whales have
been emaciated with moderate to heavy whale lice (cyamid) loads.
Necropsies have been conducted on a subset of whales with additional
findings of vessel strike in three whales and entanglement in one
whale. In Mexico, 50-55 percent of the free-ranging whales observed in
the lagoons in winter have been reported as ``skinny'' compared to the
annual average of 10-12 percent ``skinny'' whales normally seen. The
cause of the UME is as yet undetermined. For more information, please
visit: <a href="http://www.fisheries.noaa.gov/national/marine-life-distress/2019-2020-gray-whale-unusual-mortality-event-along-west-coast-and">www.fisheries.noaa.gov/national/marine-life-distress/2019-2020-gray-whale-unusual-mortality-event-along-west-coast-and</a>.
Another recent, notable UME involved large whales and occurred in
the western Gulf of Alaska and off of British Columbia, Canada.
Beginning in May 2015, elevated large whale mortalities (primarily fin
and humpback whales) occurred in the areas around Kodiak Island,
Afognak Island, Chirikof Island, the Semidi Islands, and the southern
shoreline of the Alaska Peninsula. Although most carcasses have been
non-retrievable as they were discovered floating and in a state of
moderate to severe decomposition, the UME is likely attributable to
ecological factors, i.e., the 2015 El Ni[ntilde]o, ``warm water blob,''
and the Pacific Coast domoic acid bloom. The UME was closed in 2016.
More information is available online at <a href="http://www.fisheries.noaa.gov/national/marine-life-distress/2015-2016-large-whale-unusual-mortality-event-western-gulf-alaska">www.fisheries.noaa.gov/national/marine-life-distress/2015-2016-large-whale-unusual-mortality-event-western-gulf-alaska</a>.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 2.
Table 2--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids,
[[Page 37294]]
especially in the higher frequency range (Hemil[auml] et al., 2006;
Kastelein et al., 2009; Reichmuth and Holt, 2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Twenty-two marine mammal species (17 cetacean and 5 pinniped (3 otariid
and 2 phocid) species) are considered herein. Of the cetacean species
that may be present, seven are classified as low-frequency cetaceans
(i.e., all mysticete species), eight are classified as mid-frequency
cetaceans (i.e., all delphinid and ziphiid species and the sperm
whale), and two are classified as high-frequency cetaceans (i.e.,
porpoises).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary of the ways that L-DEO's specified
activity may impact marine mammals and their habitat. Detailed
descriptions of the potential effects of similar specified activities
have been provided in other recent Federal Register notices, including
for survey activities using the same methodology and over a similar
amount of time, and affecting similar species (e.g., 83 FR 29212, June
22, 2018; 84 FR 14200, April 9, 2019; 85 FR 19580, April 7, 2020). No
significant new information is available, and we refer the reader to
these documents for additional detail. The Estimated Take section
includes a quantitative analysis of the number of individuals that are
expected to be taken by L-DEO's activity. The Negligible Impact
Analysis and Determination section considers the potential effects of
the specified activity, the Estimated Take section, and the Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship of individuals
and how those impacts on individuals are likely to impact marine mammal
species or stocks. The notice of proposed IHA (86 FR 30006; June 4,
2021) provided a discussion and background information regarding active
acoustic sound sources and acoustic terminology, which is not repeated
here. Please see that notice for additional information.
Summary on Specific Potential Effects of Acoustic Sound Sources
Underwater sound from active acoustic sources can include one or
more of the following: Temporary or permanent hearing impairment, non-
auditory physical or physiological effects, behavioral disturbance,
stress, and masking. The degree of effect is intrinsically related to
the signal characteristics, received level, distance from the source,
and duration of the sound exposure. Marine mammals exposed to high-
intensity sound, or to lower-intensity sound for prolonged periods, can
experience hearing threshold shift (TS), which is the loss of hearing
sensitivity at certain frequency ranges (Finneran, 2015). TS can be
permanent (PTS), in which case the loss of hearing sensitivity is not
fully recoverable, or temporary (TTS), in which case the animal's
hearing threshold would recover over time (Southall et al., 2007).
Due to the characteristics of airgun arrays as a distributed sound
source, maximum estimated Level A harassment isopleths for species of
certain hearing groups are assumed to fall within the near field of the
array. For these species, i.e., mid-frequency cetaceans and all
pinnipeds, animals in the vicinity of L-DEO's proposed seismic survey
activity are unlikely to incur PTS. For low-frequency cetaceans and
high-frequency cetaceans, potential exposures sufficient to cause low-
level PTS may occur on the basis of cumulative exposure level and
instantaneous exposure to peak pressure levels, respectively. However,
when considered in conjunction with the potential for aversive
behavior, relative motion of the exposed animal and the sound source,
and the anticipated efficacy of the proposed mitigation requirements, a
reasonable conclusion may be drawn that PTS is not a likely outcome for
any species. However, we propose to authorize take by Level A
harassment, where indicated by the quantitative exposure analysis, for
species from the low- and high-frequency cetacean hearing groups.
Please see Estimated Take and Mitigation for further discussion.
Behavioral disturbance may include a variety of effects, including
subtle changes in behavior (e.g., minor or brief avoidance of an area
or changes in vocalizations), more conspicuous changes in similar
behavioral activities, and more sustained and/or potentially severe
reactions, such as displacement from or abandonment of high-quality
habitat. Behavioral responses to sound are highly variable and context-
specific and any reactions depend on numerous intrinsic and extrinsic
factors (e.g., species, state of maturity, experience, current
activity, reproductive state, auditory sensitivity, time of day), as
well as the interplay between factors. Available studies show wide
variation in response to underwater sound; therefore, it is difficult
to predict specifically how any given sound in a particular instance
might affect marine mammals perceiving the signal.
In addition, sound can disrupt behavior through masking, or
interfering with, an animal's ability to detect, recognize, or
discriminate between acoustic signals of interest (e.g., those used for
intraspecific communication and social interactions, prey detection,
predator avoidance, navigation). Masking occurs when the receipt of a
sound is interfered with by another coincident sound at similar
frequencies and at similar or higher intensity, and may occur whether
the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., shipping, sonar, seismic
exploration) in origin.
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, zooplankton) (i.e., effects to marine mammal
habitat). Prey species exposed to sound might move away from the sound
source, experience TTS, experience masking of biologically relevant
sounds, or show no obvious direct effects. The most likely impacts (if
any) for most prey species in a given area would be temporary avoidance
of the area. Surveys using active acoustic sound sources move through
an area relatively quickly, limiting exposure to multiple pulses. In
all cases, sound levels would return to ambient once a survey ends and
the noise source is shut down and, when exposure to sound ends,
behavioral and/or physiological responses are expected to end
relatively quickly. Finally, the survey equipment will not have
significant impacts to the seafloor and does not represent a source of
pollution.
Vessel Strike
Vessel collisions with marine mammals, or ship strikes, can result
in death or serious injury of the animal. These interactions are
typically associated with large whales, which are less maneuverable
than are smaller cetaceans or pinnipeds in relation to large vessels.
The severity of injuries typically depends on the size and speed of the
vessel, with the probability of death or serious injury increasing as
vessel speed increases (Knowlton and Kraus, 2001; Laist et al., 2001;
Vanderlaan and Taggart, 2007; Conn and Silber, 2013). Impact forces
increase with speed, as does the probability of a strike at a given
distance (Silber et al., 2010; Gende et al., 2011). The chances of a
lethal injury decline from approximately 80 percent at 15 kn to
approximately 20 percent at 8.6 kn. At speeds below 11.8 kn, the
chances of lethal injury drop below 50 percent (Vanderlaan and Taggart,
2007).
[[Page 37295]]
Ship strikes generally involve commercial shipping, which is much
more common in both space and time than is geophysical survey activity
and which typically involves larger vessels moving at faster speeds.
Jensen and Silber (2004) summarized ship strikes of large whales
worldwide from 1975-2003 and found that most collisions occurred in the
open ocean and involved large vessels (e.g., commercial shipping).
Commercial fishing vessels were responsible for 3 percent of recorded
collisions, while no such incidents were reported for geophysical
survey vessels during that time period.
For vessels used in geophysical survey activities, vessel speed
while towing gear is typically only 4-5 kn. At these speeds, both the
possibility of striking a marine mammal and the possibility of a strike
resulting in serious injury or mortality are so low as to be
discountable. At average transit speed for geophysical survey vessels
(approximately 10 kn), the probability of serious injury or mortality
resulting from a strike (if it occurred) is less than 50 percent
(Vanderlaan and Taggart, 2007; Conn and Silber, 2013). However, the
likelihood of a strike actually happening is again low given the
smaller size of these vessels and generally slower speeds. We
anticipate that vessel collisions involving seismic data acquisition
vessels towing gear, while not impossible, represent unlikely,
unpredictable events for which there are no preventive measures. Given
the required mitigation measures, the relatively slow speeds of vessels
towing gear, the presence of bridge crew watching for obstacles at all
times (including marine mammals), the presence of marine mammal
observers, and the small number of seismic survey cruises relative to
commercial ship traffic, we believe that the possibility of ship strike
is discountable and, further, that were a strike of a large whale to
occur, it would be unlikely to result in serious injury or mortality.
No incidental take resulting from ship strike is anticipated or
proposed for authorization, and this potential effect of the specified
activity will not be discussed further in the following analysis.
The potential effects of L-DEO's specified survey activity are
expected to be limited to Level B harassment consisting of behavioral
harassment and/or temporary auditory effects and, for certain species
of low- and high-frequency cetaceans only, low-level permanent auditory
effects. No permanent auditory effects for any species belonging to
other hearing groups, or significant impacts to marine mammal habitat,
including prey, are expected.
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through the 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
seismic airguns 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) for mysticetes and high-
frequency cetaceans (i.e., porpoises). The mitigation and monitoring
measures are expected to minimize the severity of such taking to the
extent practicable.
As described previously, no serious injury or 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 numbers.
Acoustic Thresholds
NMFS uses 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--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). NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals may
be behaviorally harassed (i.e., Level B harassment) when exposed to
underwater anthropogenic noise above received levels of 160 dB re 1
microPascal (root mean square) ([mu]Pa (rms)) for the impulsive sources
(i.e., seismic airguns) evaluated here.
Level A Harassment--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). L-DEO's
seismic survey includes the use of impulsive (seismic airguns) sources.
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
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
[[Page 37296]]
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa2s. 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 and other relevant information that will feed into identifying
the area ensonified above the acoustic thresholds.
L-DEO's modeling methodologies are described in greater detail in
Appendix A of L-DEO's IHA application. The 2D survey will acquire data
using the 36-airgun array with a total discharge volume of 6,600 in\3\
at a maximum tow depth of 12 m. L-DEO's modeling approach uses ray
tracing for the direct wave traveling from the array to the receiver
and its associated source ghost (reflection at the air-water interface
in the vicinity of the array), in a constant-velocity half-space
(infinite homogeneous ocean layer, unbounded by a seafloor). To
validate the model results, L-DEO measured propagation of pulses from
the 36-airgun array at a tow depth of 6 m in the Gulf of Mexico, for
deep water (~1,600 m), intermediate water depth on the slope (~600-
1,100 m), and shallow water (~50 m) (Tolstoy et al., 2009; Diebold et
al., 2010).
L-DEO collected a MCS data set from R/V Langseth (array towed at 9
m depth) on an 8-km streamer in 2012 on the shelf of the Cascadia
Margin off of Washington in water up to 200 m deep that allowed Crone
et al. (2014) to analyze the hydrophone streamer data (>1,100
individual shots). These empirical data were then analyzed to determine
in situ sound levels for shallow and upper intermediate water depths.
These data suggest that modeled radii were 2-3 times larger than the
measured radii in shallow water. Similarly, data collected by Crone et
al. (2017) during a survey off New Jersey in 2014 and 2015 confirmed
that in situ measurements collected by the R/V Langseth hydrophone
streamer were 2-3 times smaller than the predicted radii.
L-DEO model results are used to determine the assumed radial
distance to the 160-dB rms threshold for these arrays in deep water
(>1,000 m) (down to a maximum water depth of 2,000 m). Water depths in
the project area may be up to 2,800 m, but marine mammals in the region
are generally not anticipated to dive below 2,000 m (e.g., Costa and
Williams, 1999). L-DEO typically derives estimated distances for
intermediate water depths by applying a correction factor of 1.5 to the
model results for deep water. In this case, the estimated radial
distance for intermediate (100-1,000 m) and shallow (<100 m) water
depths is taken from Crone et al. (2014), as these empirical data were
collected in the same region as this survey. A correction factor of
1.15 was applied to account for differences in array tow depth.
The estimated distances to the Level B harassment isopleths for the
array are shown in Table 4.
Table 4--Predicted Radial Distances to Isopleths Corresponding to Level B Harassment Threshold
----------------------------------------------------------------------------------------------------------------
Level B
Source and volume Tow depth (m) Water depth harassment
(m) zone (m)
----------------------------------------------------------------------------------------------------------------
36 airgun array; 6,600 in\3\.................................... 12 >1000 \1\ 6,733
100-1000 \2\ 9,468
<100 \2\ 12,650
----------------------------------------------------------------------------------------------------------------
\1\ Distance based on L-DEO model results.
\2\ Based on empirical data from Crone et al. (2014) with scaling.
Predicted distances to Level A harassment isopleths, which vary
based on marine mammal hearing groups, were calculated based on
modeling performed by L-DEO using the NUCLEUS source modeling software
program and the NMFS User Spreadsheet, described below. The acoustic
thresholds for impulsive sounds (e.g., airguns) contained in the
Technical Guidance were presented as dual metric acoustic thresholds
using both cumulative sound exposure level (SEL<INF>cum</INF>) and peak
sound pressure metrics (NMFS 2018). As dual metrics, NMFS considers
onset of PTS (Level A harassment) to have occurred when either one of
the two metrics is exceeded (i.e., metric resulting in the largest
isopleth). The SEL<INF>cum</INF> metric considers both level and
duration of
[[Page 37297]]
exposure, as well as auditory weighting functions by marine mammal
hearing group. In recognition of the fact that the requirement to
calculate Level A harassment ensonified areas could be more technically
challenging to predict due to the duration component and the use of
weighting functions in the new SEL<INF>cum</INF> thresholds, NMFS
developed an optional User Spreadsheet that includes tools to help
predict a simple isopleth that can be used in conjunction with marine
mammal density or occurrence to facilitate the estimation of take
numbers.
The values for SEL<INF>cum</INF> and peak SPL for the Langseth
airgun arrays were derived from calculating the modified far-field
signature. The farfield signature is often used as a theoretical
representation of the source level. To compute the farfield signature,
the source level is estimated at a large distance below the array
(e.g., 9 km), and this level is back projected mathematically to a
notional distance of 1 m from the array's geometrical center. However,
when the source is an array of multiple airguns separated in space, the
source level from the theoretical farfield signature is not necessarily
the best measurement of the source level that is physically achieved at
the source (Tolstoy et al., 2009). Near the source (at short ranges,
distances <1 km), the pulses of sound pressure from each individual
airgun in the source array do not stack constructively, as they do for
the theoretical farfield signature. The pulses from the different
airguns spread out in time such that the source levels observed or
modeled are the result of the summation of pulses from a few airguns,
not the full array (Tolstoy et al., 2009). At larger distances, away
from the source array center, sound pressure of all the airguns in the
array stack coherently, but not within one time sample, resulting in
smaller source levels (a few dB) than the source level derived from the
farfield signature. Because the farfield signature does not take into
account the large array effect near the source and is calculated as a
point source, the modified farfield signature is a more appropriate
measure of the sound source level for distributed sound sources, such
as airgun arrays. L-DEO used the acoustic modeling methodology as used
for estimating Level B harassment distances with a small grid step of 1
m in both the inline and depth directions. The propagation modeling
takes into account all airgun interactions at short distances from the
source, including interactions between subarrays, which are modeled
using the NUCLEUS software to estimate the notional signature and
MATLAB software to calculate the pressure signal at each mesh point of
a grid.
In order to more realistically incorporate the Technical Guidance's
weighting functions over the seismic array's full acoustic band,
unweighted spectrum data for the Langseth's airgun array (modeled in 1
Hz bands) was used to make adjustments (dB) to the unweighted spectrum
levels, by frequency, according to the weighting functions for each
relevant marine mammal hearing group. These adjusted/weighted spectrum
levels were then converted to pressures ([mu]Pa) in order to integrate
them over the entire broadband spectrum, resulting in broadband
weighted source levels by hearing group that could be directly
incorporated within the User Spreadsheet (i.e., to override the
Spreadsheet's more simple weighting factor adjustment). Using the User
Spreadsheet's ``safe distance'' methodology for mobile sources
(described by Sivle et al., 2014) with the hearing group-specific
weighted source levels, and inputs assuming spherical spreading
propagation and information specific to the planned survey (i.e., the
2.2 m/s source velocity and (worst-case) 23-s shot interval), potential
radial distances to auditory injury zones were then calculated for
SEL<INF>cum</INF> thresholds.
Inputs to the User Spreadsheets in the form of estimated source
levels are shown in Appendix A of L-DEO's application. User
Spreadsheets used by L-DEO to estimate distances to Level A harassment
isopleths for the airgun arrays are also provided in Appendix A of the
application. Outputs from the User Spreadsheets in the form of
estimated distances to Level A harassment isopleths for the survey are
shown in Table 5. As described above, NMFS considers onset of PTS
(Level A harassment) to have occurred when either one of the dual
metrics (SEL<INF>cum</INF> and Peak SPL<INF>flat</INF>) is exceeded
(i.e., metric resulting in the largest isopleth).
Table 5--Modeled Radial Distances (m) to Isopleths Corresponding to Level A Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m)
Source (volume) Threshold -------------------------------------------------------------------------------
LF cetaceans MF cetaceans HF cetaceans Phocids Otariids
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-airgun array (6,600 in\3\)............ SELcum....................... 320 0 1 10 0
Peak......................... 39 14 268 44 11
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note that because of some of the assumptions included in the
methods used (e.g., stationary receiver with no vertical or horizontal
movement in response to the acoustic source), isopleths produced may be
overestimates to some degree, which will ultimately result in some
degree of overestimation of Level A harassment. However, these tools
offer the best way to predict appropriate isopleths when more
sophisticated 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 mobile sources,
such as this seismic survey, the User Spreadsheet predicts the closest
distance at which a stationary animal would not incur PTS if the sound
source traveled by the animal in a straight line at a constant speed.
Auditory injury is unlikely to occur for mid-frequency cetaceans,
otariid pinnipeds, and phocid pinnipeds given very small modeled zones
of injury for those species (all estimated zones less than 15 m for
mid-frequency cetaceans and otariid pinnipeds, up to a maximum of 44 m
for phocid pinnipeds), in context of distributed source dynamics. The
source level of the array is a theoretical definition assuming a point
source and measurement in the far-field of the source (MacGillivray,
2006). As described by Caldwell and Dragoset (2000), an array is not a
point source, but one that spans a small area. In the far-field,
individual elements in arrays will effectively work as one source
because individual pressure peaks will have coalesced into one
relatively broad pulse. The array can then be considered a ``point
source.'' For distances within the near-field, i.e., approximately 2-3
times the array dimensions, pressure peaks from individual elements do
not arrive simultaneously because the observation point is not
equidistant from each element. The effect is
[[Page 37298]]
destructive interference of the outputs of each element, so that peak
pressures in the near-field will be significantly lower than the output
of the largest individual element. Here, the peak isopleth distances
would in all cases be expected to be within the near-field of the array
where the definition of source level breaks down. Therefore, actual
locations within this distance of the array center where the sound
level exceeds peak SPL isopleth distances would not necessarily exist.
In general, Caldwell and Dragoset (2000) suggest that the near-field
for airgun arrays is considered to extend out to approximately 250 m.
We provided additional discussion and quantitative support for this
theoretical argument in the notice of proposed IHA. Please see that
notice (86 FR 30006; June 4, 2021) for additional information.
In consideration of the received sound levels in the near-field as
described above, we expect the potential for Level A harassment of mid-
frequency cetaceans, otariid pinnipeds, and phocid pinnipeds to be de
minimis, even before the likely moderating effects of aversion and/or
other compensatory behaviors (e.g., Nachtigall et al., 2018) are
considered. We do not believe that Level A harassment is a likely
outcome for any mid-frequency cetacean, otariid pinniped, or phocid
pinniped and do not authorize any Level A harassment for these species.
Marine Mammal Occurrence
Information about the presence, density, and group dynamics of
marine mammals that informs the take calculations was provided in our
notice of proposed IHA (86 FR 30006; June 4, 2021). That information is
not re-printed here. For additional detail, please see the notice of
proposed IHA. Density values were provided in Table 6 of that notice.
No new density information is available since we published the notice
of proposed IHA, and no changes have been made. We relied largely upon
the Navy's Marine Species Density Database (DoN, 2019, 2021), which is
currently the most comprehensive compendium for density data available
for the GOA and the only source of density data available for southeast
Alaska.
As described above in Changes from the Proposed IHA, the estimated
take of Steller sea lions in Canadian territorial waters was incorrect.
The correct density values were provided in Table 6 of the notice of
proposed IHA; however, an erroneous density value was applied in
producing the incorrect estimate provided in Table 8 of the notice of
proposed IHA. That error has been corrected herein (see Table 7).
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate. In order to estimate
the number of marine mammals predicted to be exposed to sound levels
that would result in Level A or Level B harassment, radial distances
from the airgun array to predicted isopleths corresponding to the Level
A harassment and Level B harassment thresholds are calculated, as
described above. Those radial distances are then used to calculate the
area(s) around the airgun array predicted to be ensonified to sound
levels that exceed the Level A and Level B harassment thresholds. The
distance for the 160-dB threshold (based on L-DEO model results) was
used to draw a buffer around every transect line in GIS to determine
the total ensonified area in each depth category. Estimated incidents
of exposure above Level A and Level B harassment criteria are presented
in Table 6. For additional details regarding calculations of ensonified
area, please see Appendix D of L-DEO's application. As noted
previously, L-DEO has added 25 percent in the form of operational days,
which is equivalent to adding 25 percent to the line-kms to be
surveyed. This accounts for the possibility that additional operational
days are required, but likely results in an overestimate of actual
exposures.
For North Pacific right whales, the recent observation of an
individual whale in Canadian waters where the survey will occur means
that the potential for an encounter, while still unpredictable, is
heightened. While we here assume that a North Pacific right whale
encounter may occur, we also assume that such an event is unlikely
(during two weeks of survey effort, the DFO researchers had a single
encounter) and would occur no more than once during the survey. In
order to determine the appropriate take number for authorization, we
reviewed available information for North Pacific right whales. While
most observations outside of typical habitat near Kodiak Island in the
northern GOA and in the eastern Bering Sea have been of single
individuals, the average group size during observations in more typical
habitat is of two whales (Shelden et al., 2005; Waite et al., 2003;
Wade et al., 2011; Muto et al., 2020). The assumption that an encounter
will occur once, in conjunction with a conservative assumption that the
encounter could be with an average group, supports a determination that
authorization of two takes is appropriate as a precautionary approach
to ensuring that potential effects to North Pacific right whales are
evaluated and that unauthorized take is avoided. We also note that
application of density data from the Navy's northern GOA Temporary
Marine Activities Area would produce an estimate of two exposures.
Although it is likely that this density information is not an accurate
representation of North Pacific right whale occurrence off of southeast
Alaska and British Columbia, this approach provides additional support
for the authorization of two takes.
As previously noted, NMFS cannot authorize incidental take under
the MMPA that may occur within the territorial seas of foreign nations
(from 0-12 nmi (22.2 km) from shore), as the MMPA does not apply in
those waters. However, NMFS has still calculated the estimated level of
incidental take in the entire activity area (including Canadian
territorial waters) as part of the analysis supporting our
determination under the MMPA that the activity will have a negligible
impact on the affected species. The total estimated take in U.S. and
Canadian waters is presented in Table 7 (see Negligible Impact Analysis
and Determination).
The estimated marine mammal exposures above harassment thresholds
are generally assumed here to equate to take, and the estimates form
the basis for our take authorization numbers. For the species for which
NMFS does not expect there to be a reasonable potential for take by
Level A harassment to occur, i.e., mid-frequency cetaceans and all
pinnipeds, the estimated exposures above Level A harassment thresholds
have been added to the estimated exposures above the Level B harassment
threshold to produce a total number of incidents of take by Level B
harassment that is authorized. Estimated exposures and take numbers for
authorization are shown in Table 6. Regarding humpback whale take
numbers, we assume that whales encountered will follow Wade (2017),
i.e., that 96.1 percent of takes would accrue to the Hawaii DPS and 3.8
percent to the Mexico DPS. Of the estimated take of gray whales, and
based on guidance provided through interagency consultation under
section 7 of the ESA, we assume that 0.1 percent of encountered whales
would be from the WNP stock and authorize take accordingly. For Steller
sea lions, 2.2 percent are assumed to belong to the western DPS
(Hastings et al., 2020).
[[Page 37299]]
Table 6--Estimated Taking by Level A and Level B Harassment, and Percentage of Population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated Estimated Authorized Authorized
Species Stock Level B Level A Level B Level A Total take Percent of
harassment harassment harassment harassment stock \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale \2\..... .................... 2 0 2 0 2 6.1
Gray whale........................ WNP................. 1,450 45 2 0 2 0.7
ENP................. 1,448 45 1,493 5.5
Humpback whale.................... .................... 403 14 403 14 417 4.1
Blue whale........................ .................... 31 1 31 1 32 2.1
Fin whale \3\..................... .................... 873 44 873 44 917 n/a
Sei whale......................... .................... 34 1 34 1 35 6.7
Minke whale \3\................... .................... 57 2 57 2 59 n/a
Sperm whale \3\................... .................... 131 0 131 0 131 n/a
Baird's beaked whale \3\.......... .................... 29 0 29 0 29 n/a
Stejneger's beaked whale \3\...... .................... 120 0 120 0 120 n/a
Cuvier's beaked whale \3\......... .................... 114 0 114 0 114 n/a
Pacific white-sided dolphin....... .................... 1,371 3 1,374 0 1,374 5.1
Northern right whale dolphin...... .................... 922 5 927 0 927 3.5
Risso's dolphin \4\............... .................... 1 0 22 0 22 0.3
Killer whale...................... Offshore............ 290 0 290 0 290 96.7
GOA/BSAI Transient.. .............. .............. .............. .............. .............. 49.4
WC Transient........ .............. .............. .............. .............. .............. 83.1
AK Resident......... .............. .............. .............. .............. .............. 12.4
Northern Resident... .............. .............. .............. .............. .............. 96.0
Dall's porpoise................... .................... 5,661 178 5,661 178 5,839 7.0
Harbor porpoise................... .................... 990 26 990 26 1,016 n/a
Northern fur seal................. .................... 5,804 8 5,812 0 5,812 1.0
California sea lion............... .................... 1,256 1 1,258 0 1,258 0.5
Steller sea lion.................. WDPS................ 2,433 2 54 0 54 0.1
EDPS................ .............. .............. 2,381 0 2,381 5.5
Northern elephant seal............ .................... 6,811 39 6,850 0 6,850 3.8
Harbor seal....................... Sitka/Chatham Strait 5,992 21 6,012 0 6,012 45.2
Dixon/Cape Decision. .............. .............. .............. .............. .............. 25.6
Clarence Strait..... .............. .............. .............. .............. .............. 21.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ In most cases, where multiple stocks are being affected, for the purposes of calculating the percentage of the stock impacted, the take is being
analyzed as if all takes occurred within each stock. Where necessary, additional discussion is provided in the Small Numbers section.
\2\ Take number represents qualitative consideration of likelihood of encounter, average group size, and available density information.
\3\ As noted in Table 1, there is no estimate of abundance available for these species.
\4\ Estimated exposure of one Risso's dolphin increased to group size of 22 (Barlow, 2016).
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
In order to satisfy the MMPA's least practicable adverse impact
standard, NMFS has evaluated a suite of basic mitigation protocols for
seismic surveys that are required regardless of the status of a stock.
Additional or enhanced protections may be required for species whose
stocks are in particularly poor health and/or are subject to some
significant additional stressor that lessens that stock's ability to
weather the effects of the specified activities without worsening its
status. We reviewed seismic mitigation protocols required or
recommended elsewhere (e.g., HESS, 1999; DOC, 2013; IBAMA, 2018; Kyhn
et al., 2011; JNCC, 2017; DEWHA, 2008; BOEM, 2016; DFO, 2008; GHFS,
2015; MMOA, 2016; Nowacek et al., 2013; Nowacek and Southall, 2016),
recommendations received during public comment periods for previous
actions, and the available scientific literature. We also considered
recommendations given in a number of review articles (e.g., Weir and
Dolman, 2007; Compton et al., 2008; Parsons et al., 2009; Wright and
Cosentino, 2015; Stone, 2015b). This exhaustive review and
consideration of public comments regarding previous, similar activities
has led to development of the protocols included here.
Vessel-Based Visual Mitigation Monitoring
Visual monitoring requires the use of trained observers (herein
referred to as visual protected species observers (PSOs)) to scan the
ocean surface for the presence of marine mammals. The area to be
scanned visually includes primarily the exclusion zone (EZ),
[[Page 37300]]
within which observation of certain marine mammals requires shutdown of
the acoustic source, but also a buffer zone and, to the extent possible
depending on conditions, the surrounding waters. The buffer zone means
an area beyond the EZ to be monitored for the presence of marine
mammals that may enter the EZ. During pre-start clearance monitoring
(i.e., before ramp-up begins), the buffer zone also acts as an
extension of the EZ in that observations of marine mammals within the
buffer zone would also prevent airgun operations from beginning (i.e.,
ramp-up). The buffer zone encompasses the area at and below the sea
surface from the edge of the 0-500 m EZ, out to a radius of 1,000 m
from the edges of the airgun array (500-1,000 m). This 1,000-m zone (EZ
plus buffer) represents the pre-start clearance zone. Visual monitoring
of the EZ and adjacent waters is intended to establish and, when visual
conditions allow, maintain zones around the sound source that are clear
of marine mammals, thereby reducing or eliminating the potential for
injury and minimizing the potential for more severe behavioral
reactions for animals occurring closer to the vessel. Visual monitoring
of the buffer zone is intended to (1) provide additional protection to
na[iuml]ve marine mammals that may be in the area during pre-start
clearance, and (2) during airgun use, aid in establishing and
maintaining the EZ by alerting the visual observer and crew of marine
mammals that are outside of, but may approach and enter, the EZ.
L-DEO must use dedicated, trained, NMFS-approved PSOs. The PSOs
must have no tasks other than to conduct observational effort, record
observational data, and communicate with and instruct relevant vessel
crew with regard to the presence of marine mammals and mitigation
requirements. PSO resumes shall be provided to NMFS for approval.
At least one of the visual and two of the acoustic PSOs (discussed
below) aboard the vessel must have a minimum of 90 days at-sea
experience working in those roles, respectively, with no more than 18
months elapsed since the conclusion of the at-sea experience. One
visual PSO with such experience shall be designated as the lead for the
entire protected species observation team. The lead PSO shall serve as
primary point of contact for the vessel operator and ensure all PSO
requirements per the IHA are met. To the maximum extent practicable,
the experienced PSOs should be scheduled to be on duty with those PSOs
with appropriate training but who have not yet gained relevant
experience.
During survey operations (e.g., any day on which use of the
acoustic source is planned to occur, and whenever the acoustic source
is in the water, whether activated or not), a minimum of two visual
PSOs must be on duty and conducting visual observations at all times
during daylight hours (i.e., from 30 minutes prior to sunrise through
30 minutes following sunset). Visual monitoring of the pre-start
clearance zone must begin no less than 30 minutes prior to ramp-up, and
monitoring must continue until one hour after use of the acoustic
source ceases or until 30 minutes past sunset. Visual PSOs shall
coordinate to ensure 360[deg] visual coverage around the vessel from
the most appropriate observation posts, and shall conduct visual
observations using binoculars and the naked eye while free from
distractions and in a consistent, systematic, and diligent manner.
PSOs shall establish and monitor the exclusion and buffer zones.
These zones shall be based upon the radial distance from the edges of
the acoustic source (rather than being based on the center of the array
or around the vessel itself). During use of the acoustic source (i.e.,
anytime airguns are active, including ramp-up), detections of marine
mammals within the buffer zone (but outside the EZ) shall be
communicated to the operator to prepare for the potential shutdown of
the acoustic source. Visual PSOs will immediately communicate all
observations to the on duty acoustic PSO(s), including any
determination by the PSO regarding species identification, distance,
and bearing and the degree of confidence in the determination. Any
observations of marine mammals by crew members shall be relayed to the
PSO team. During good conditions (e.g., daylight hours; Beaufort sea
state (BSS) 3 or less), visual PSOs shall conduct observations when the
acoustic source is not operating for comparison of sighting rates and
behavior with and without use of the acoustic source and between
acquisition periods, to the maximum extent practicable.
Visual PSOs may be on watch for a maximum of 4 consecutive hours
followed by a break of at least one hour between watches and may
conduct a maximum of 12 hours of observation per 24-hour period.
Combined observational duties (visual and acoustic but not at same
time) may not exceed 12 hours per 24-hour period for any individual
PSO.
Passive Acoustic Monitoring
Acoustic monitoring means the use of trained personnel (sometimes
referred to as passive acoustic monitoring (PAM) operators, herein
referred to as acoustic PSOs) to operate PAM equipment to acoustically
detect the presence of marine mammals. Acoustic monitoring involves
acoustically detecting marine mammals regardless of distance from the
source, as localization of animals may not always be possible. Acoustic
monitoring is intended to further support visual monitoring (during
daylight hours) in maintaining an EZ around the sound source that is
clear of marine mammals. In cases where visual monitoring is not
effective (e.g., due to weather, nighttime), acoustic monitoring may be
used to allow certain activities to occur, as further detailed below.
PAM will take place in addition to the visual monitoring program.
Visual monitoring typically is not effective during periods of poor
visibility or at night, and even with good visibility, is unable to
detect marine mammals when they are below the surface or beyond visual
range. Acoustic monitoring can be used in addition to visual
observations to improve detection, identification, and localization of
cetaceans. The acoustic monitoring serves to alert visual PSOs (if on
duty) when vocalizing cetaceans are detected. It is only useful when
marine mammals vocalize, but it can be effective either by day or by
night, and does not depend on good visibility. It will be monitored in
real time so that the visual observers can be advised when cetaceans
are detected.
The R/V Langseth will use a towed PAM system, which must be
monitored by at a minimum one on duty acoustic PSO beginning at least
30 minutes prior to ramp-up and at all times during use of the acoustic
source. Acoustic PSOs may be on watch for a maximum of 4 consecutive
hours followed by a break of at least one hour between watches and may
conduct a maximum of 12 hours of observation per 24-hour period.
Combined observational duties (acoustic and visual but not at same
time) may not exceed 12 hours per 24-hour period for any individual
PSO.
Survey activity may continue for 30 minutes when the PAM system
malfunctions or is damaged, while the PAM operator diagnoses the issue.
If the diagnosis indicates that the PAM system must be repaired to
solve the problem, operations may continue for an additional 5 hours
without acoustic monitoring during daylight hours only under the
following conditions:
<bullet> Sea state is less than or equal to BSS 4;
<bullet> No marine mammals (excluding delphinids) detected solely
by PAM in
[[Page 37301]]
the applicable EZ in the previous 2 hours;
<bullet> NMFS is notified via email as soon as practicable with the
time and location in which operations began occurring without an active
PAM system; and
<bullet> Operations with an active acoustic source, but without an
operating PAM system, do not exceed a cumulative total of 5 hours in
any 24-hour period.
Establishment of Exclusion and Pre-Start Clearance Zones
An EZ is a defined area within which occurrence of a marine mammal
triggers mitigation action intended to reduce the potential for certain
outcomes, e.g., auditory injury, disruption of critical behaviors. The
PSOs will establish a minimum EZ with a 500-m radius. The 500-m EZ will
be based on radial distance from the edge of the airgun array (rather
than being based on the center of the array or around the vessel
itself). With certain exceptions (described below), if a marine mammal
appears within or enters this zone, the acoustic source will be shut
down.
The pre-start clearance zone is defined as the area that must be
clear of marine mammals prior to beginning ramp-up of the acoustic
source, and includes the EZ plus the buffer zone. Detections of marine
mammals within the pre-start clearance zone will prevent airgun
operations from beginning (i.e., ramp-up).
The 500-m EZ is intended to be precautionary in the sense that it
would be expected to contain sound exceeding the injury criteria for
all cetacean hearing groups, (based on the dual criteria of
SEL<INF>cum</INF> and peak sound pressure level (SPL)), while also
providing a consistent, reasonably observable zone within which PSOs
will typically be able to conduct effective observational effort.
Additionally, a 500-m EZ is expected to minimize the likelihood that
marine mammals will be exposed to levels likely to result in more
severe behavioral responses. Although significantly greater distances
may be observed from an elevated platform under good conditions, we
believe that 500 m is likely regularly attainable for PSOs using the
naked eye during typical conditions. The pre-start clearance zone
simply represents the addition of a buffer to the EZ, doubling the EZ
size during pre-clearance.
An extended EZ of 1,500 m must be enforced for all beaked whales.
No buffer of this extended EZ is required.
Pre-Start Clearance and Ramp-Up
Ramp-up (sometimes referred to as ``soft start'') means the gradual
and systematic increase of emitted sound levels from an airgun array.
Ramp-up begins by first activating a single airgun of the smallest
volume, followed by doubling the number of active elements in stages
until the full complement of an array's airguns are active. Each stage
should be approximately the same duration, and the total duration
should not be less than approximately 20 minutes. The intent of pre-
start clearance observation (30 minutes) is to ensure no protected
species are observed within the pre-clearance zone (or extended EZ, for
beaked whales) prior to the beginning of ramp-up. During pre-start
clearance period is the only time observations of marine mammals in the
buffer zone would prevent operations (i.e., the beginning of ramp-up).
The intent of ramp-up is to warn marine mammals of pending seismic
operations and to allow sufficient time for those animals to leave the
immediate vicinity. A ramp-up procedure, involving a step-wise increase
in the number of airguns firing and total array volume until all
operational airguns are activated and the full volume is achieved, is
required at all times as part of the activation of the acoustic source.
All operators must adhere to the following pre-start clearance and
ramp-up requirements:
<bullet> The operator must notify a designated PSO of the planned
start of ramp-up as agreed upon with the lead PSO; the notification
time should not be less than 60 minutes prior to the planned ramp-up in
order to allow the PSOs time to monitor the pre-start clearance zone
(and extended EZ) for 30 minutes prior to the initiation of ramp-up
(pre-start clearance);
<bullet> Ramp-ups shall be scheduled so as to minimize the time
spent with the source activated prior to reaching the designated run-
in;
<bullet> One of the PSOs conducting pre-start clearance
observations must be notified again immediately prior to initiating
ramp-up procedures and the operator must receive confirmation from the
PSO to proceed;
<bullet> Ramp-up may not be initiated if any marine mammal is
within the applicable exclusion or buffer zone. If a marine mammal is
observed within the pre-start clearance zone (or extended EZ, for
beaked whales) during the 30 minute pre-start clearance period, ramp-up
may not begin until the animal(s) has been observed exiting the zones
or until an additional time period has elapsed with no further
sightings (15 minutes for small odontocetes and pinnipeds, and 30
minutes for all mysticetes and all other odontocetes, including sperm
whales, beaked whales, and large delphinids, such as killer whales);
<bullet> Ramp-up shall begin by activating a single airgun of the
smallest volume in the array and shall continue in stages by doubling
the number of active elements at the commencement of each stage, with
each stage of approximately the same duration. Duration shall not be
less than 20 minutes. The operator must provide information to the PSO
documenting that appropriate procedures were followed;
<bullet> PSOs must monitor the pre-start clearance zone (and
extended EZ) during ramp-up, and ramp-up must cease and the source must
be shut down upon detection of a marine mammal within the applicable
zone. Once ramp-up has begun, detections of marine mammals within the
buffer zone do not require shutdown, but such observation shall be
communicated to the operator to prepare for the potential shutdown;
<bullet> Ramp-up may occur at times of poor visibility, including
nighttime, if appropriate acoustic monitoring has occurred with no
detections in the 30 minutes prior to beginning ramp-up. Acoustic
source activation may only occur at times of poor visibility where
operational planning cannot reasonably avoid such circumstances;
<bullet> If the acoustic source is shut down for brief periods
(i.e., less than 30 minutes) for reasons other than that described for
shutdown (e.g., mechanical difficulty), it may be activated again
without ramp-up if PSOs have maintained constant visual and/or acoustic
observation and no visual or acoustic detections of marine mammals have
occurred within the applicable EZ. For any longer shutdown, pre-start
clearance observation and ramp-up are required. For any shutdown at
night or in periods of poor visibility (e.g., BSS 4 or greater), ramp-
up is required, but if the shutdown period was brief and constant
observation was maintained, pre-start clearance watch of 30 minutes is
not required; and
<bullet> Testing of the acoustic source involving all elements
requires ramp-up. Testing limited to individual source elements or
strings does not require ramp-up but does require pre-start clearance
of 30 min.
Shutdown
The shutdown of an airgun array requires the immediate de-
activation of all individual airgun elements of the array. Any PSO on
duty will have the authority to delay the start of survey operations or
to call for shutdown of the acoustic source if a marine mammal is
detected within the applicable EZ. The operator must also establish and
[[Page 37302]]
maintain clear lines of communication directly between PSOs on duty and
crew controlling the acoustic source to ensure that shutdown commands
are conveyed swiftly while allowing PSOs to maintain watch. When both
visual and acoustic PSOs are on duty, all detections will be
immediately communicated to the remainder of the on-duty PSO team for
potential verification of visual observations by the acoustic PSO or of
acoustic detections by visual PSOs. When the airgun array is active
(i.e., anytime one or more airguns is active, including during ramp-up)
and (1) a marine mammal appears within or enters the applicable EZ and/
or (2) a marine mammal (other than delphinids, see below) is detected
acoustically and localized within the applicable EZ, the acoustic
source will be shut down. When shutdown is called for by a PSO, the
acoustic source will be immediately deactivated and any dispute
resolved only following deactivation. Additionally, shutdown will occur
whenever PAM alone (without visual sighting), confirms presence of
marine mammal(s) in the EZ. If the acoustic PSO cannot confirm presence
within the EZ, visual PSOs will be notified but shutdown is not
required.
Following a shutdown, airgun activity will not resume until the
marine mammal has cleared the EZ. The animal would be considered to
have cleared the EZ if it is visually observed to have departed the EZ
(i.e., animal is not required to fully exit the buffer zone where
applicable), or it has not been seen within the EZ for 15 minutes for
small odontocetes and pinnipeds, or 30 minutes for all mysticetes and
all other odontocetes, including sperm whales, beaked whales, and large
delphinids, such as killer whales.
The shutdown requirement can be waived for small dolphins if an
individual is detected within the EZ. As defined here, the small
dolphin group is intended to encompass those members of the Family
Delphinidae most likely to voluntarily approach the source vessel for
purposes of interacting with the vessel and/or airgun array (e.g., bow
riding). This exception to the shutdown requirement applies solely to
specific genera of small dolphins (Lagenorhynchus and Lissodelphis).
We include this small dolphin exception because shutdown
requirements for small dolphins under all circumstances represent
practicability concerns without likely commensurate benefits for the
animals in question. Small dolphins are generally the most commonly
observed marine mammals in the specific geographic region and would
typically be the only marine mammals likely to intentionally approach
the vessel. As described above, auditory injury is extremely unlikely
to occur for mid-frequency cetaceans (e.g., delphinids), as this group
is relatively insensitive to sound produced at the predominant
frequencies in an airgun pulse while also having a relatively high
threshold for the onset of auditory injury (i.e., permanent threshold
shift).
A large body of anecdotal evidence indicates that small dolphins
commonly approach vessels and/or towed arrays during active sound
production for purposes of bow riding, with no apparent effect observed
in those delphinoids (e.g., Barkaszi et al., 2012, 2018). The potential
for increased shutdowns resulting from such a measure would require the
Langseth to revisit the missed track line to reacquire data, resulting
in an overall increase in the total sound energy input to the marine
environment and an increase in the total duration over which the survey
is active in a given area. Although other mid-frequency hearing
specialists (e.g., large delphinids) are no more likely to incur
auditory injury than are small dolphins, they are much less likely to
approach vessels. Therefore, retaining a shutdown requirement for large
delphinids would not have similar impacts in terms of either
practicability for the applicant or corollary increase in sound energy
output and time on the water. We do anticipate some benefit for a
shutdown requirement for large delphinids in that it simplifies
somewhat the total range of decision-making for PSOs and may preclude
any potential for physiological effects other than to the auditory
system as well as some more severe behavioral reactions for any such
animals in close proximity to the source vessel.
Visual PSOs shall use best professional judgment in making the
decision to call for a shutdown if there is uncertainty regarding
identification (i.e., whether the observed marine mammal(s) belongs to
one of the delphinid genera for which shutdown is waived or one of the
species with a larger EZ).
L-DEO must implement shutdown if a marine mammal species for which
take was not authorized, or a species for which authorization was
granted but the takes have been met, approaches the Level A or Level B
harassment zones. L-DEO must also implement shutdown if any of the
following are observed at any distance:
<bullet> Any large whale (defined as a sperm whale or any mysticete
species) with a calf (defined as an animal less than two-thirds the
body size of an adult observed to be in close association with an
adult);
<bullet> An aggregation of six or more large whales; and/or
<bullet> A North Pacific right whale.
Vessel Strike Avoidance
1. Vessel operators and crews must maintain a vigilant watch for
all protected species and slow down, stop their vessel, or alter
course, as appropriate and regardless of vessel size, to avoid striking
any marine mammal. A visual observer aboard the vessel must monitor a
vessel strike avoidance zone around the vessel (distances stated
below). Visual observers monitoring the vessel strike avoidance zone
may be third-party observers (i.e., PSOs) or crew members, but crew
members responsible for these duties must be provided sufficient
training to (1) distinguish marine mammals from other phenomena and (2)
broadly to identify a marine mammal as a right whale, other whale
(defined in this context as sperm whales or baleen whales other than
right whales), or other marine mammal.
2. Vessel speeds must also be reduced to 10 kn or less when mother/
calf pairs, pods, or large assemblages of cetaceans are observed near a
vessel.
3. All vessels must maintain a minimum separation distance of 500 m
from right whales. If a whale is observed but cannot be confirmed as a
species other than a right whale, the vessel operator must assume that
it is a right whale and take appropriate action.
4. All vessels must maintain a minimum separation distance of 100 m
from sperm whales and all other baleen whales.
5. All vessels must, to the maximum extent practicable, attempt to
maintain a minimum separation distance of 50 m from all other marine
mammals, with an understanding that at times this may not be possible
(e.g., for animals that approach the vessel).
6. When marine mammals are sighted while a vessel is underway, the
vessel shall take action as necessary to avoid violating the relevant
separation distance (e.g., attempt to remain parallel to the animal's
course, avoid excessive speed or abrupt changes in direction until the
animal has left the area). If marine mammals are sighted within the
relevant separation distance, the vessel must reduce speed and shift
the engine to neutral, not engaging the engines until animals are clear
of the area. This does not apply to any vessel towing gear or any
vessel that is navigationally constrained.
[[Page 37303]]
7. These requirements do not apply in any case where compliance
would create an imminent and serious threat to a person or vessel or to
the extent that a vessel is restricted in its ability to maneuver and,
because of the restriction, cannot comply.
We have carefully evaluated the suite of mitigation measures
described here and considered a range of other measures in the context
of ensuring that we prescribe the means of effecting the least
practicable adverse impact on the affected marine mammal species and
stocks and their habitat. Based on our evaluation of the required
measures, as well as other measures considered by NMFS described above,
NMFS has determined that the mitigation measures provide the means of
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.
Mitigation Measures in Canadian Waters
As stated previously, NMFS cannot authorize the incidental take of
marine mammals in the territorial seas of foreign nations, as the MMPA
does not apply in those waters. L-DEO is required to adhere to the
mitigation measures described above while operating within the U.S. EEZ
and Canadian EEZ. The requirements do not apply within Canadian
territorial waters. DFO may prescribe mitigation measures that would
apply to L-DEO's survey operations within the Canadian EEZ and Canadian
territorial waters but NMFS is currently unaware of the specifics of
any potential measures. While operating within the Canadian EEZ but
outside Canadian territorial waters, if mitigation requirements
prescribed by NMFS differ from the requirements established under
Canadian law, L-DEO would adhere to the most protective measure. For
operations in Canadian territorial waters, L-DEO would implement
measures required under Canadian law (if any).
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 ensuring that the most value is obtained from the required
monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> Mitigation and monitoring effectiveness.
Vessel-Based Visual Monitoring
As described above, PSO observations will take place during daytime
airgun operations. During seismic operations, at least five visual PSOs
will be based aboard the Langseth. Two visual PSOs will be on duty at
all time during daytime hours. Monitoring shall be conducted in
accordance with the following requirements:
<bullet> The operator shall provide PSOs with bigeye binoculars
(e.g., 25 x 150; 2.7 view angle; individual ocular focus; height
control) of appropriate quality (i.e., Fujinon or equivalent) solely
for PSO use. These shall be pedestal-mounted on the deck at the most
appropriate vantage point that provides for optimal sea surface
observation, PSO safety, and safe operation of the vessel; and
<bullet> The operator will work with the selected third-party
observer provider to ensure PSOs have all equipment (including backup
equipment) needed to adequately perform necessary tasks, including
accurate determination of distance and bearing to observed marine
mammals.
PSOs must have the following requirements and qualifications:
<bullet> PSOs shall be independent, dedicated, trained visual and
acoustic PSOs and must be employed by a third-party observer provider;
<bullet> PSOs shall have no tasks other than to conduct
observational effort (visual or acoustic), collect data, and
communicate with and instruct relevant vessel crew with regard to the
presence of protected species and mitigation requirements (including
brief alerts regarding maritime hazards);
<bullet> PSOs shall have successfully completed an approved PSO
training course appropriate for their designated task (visual or
acoustic). Acoustic PSOs are required to complete specialized training
for operating PAM systems and are encouraged to have familiarity with
the vessel with which they will be working;
<bullet> PSOs can act as acoustic or visual observers (but not at
the same time) as long as they demonstrate that their training and
experience are sufficient to perform the task at hand;
<bullet> NMFS must review and approve PSO resumes accompanied by a
relevant training course information packet that includes the name and
qualifications (i.e., experience, training completed, or educational
background) of the instructor(s), the course outline or syllabus, and
course reference material as well as a document stating successful
completion of the course;
<bullet> NMFS shall have one week to approve PSOs from the time
that the necessary information is submitted, after which PSOs meeting
the minimum requirements shall automatically be considered approved;
<bullet> PSOs must successfully complete relevant training,
including completion of all required coursework and passing (80 percent
or greater) a written and/or oral examination developed for the
training program;
<bullet> PSOs must have successfully attained a bachelor's degree
from an accredited college or university with a major in one of the
natural sciences, a minimum of 30 semester hours or equivalent in the
biological sciences, and at least one undergraduate course in math or
statistics; and
<bullet> The educational requirements may be waived if the PSO has
acquired the relevant skills through alternate
[[Page 37304]]
experience. Requests for such a waiver shall be submitted to NMFS and
must include written justification. Requests shall be granted or denied
(with justification) by NMFS within one week of receipt of submitted
information. Alternate experience that may be considered includes, but
is not limited to (1) secondary education and/or experience comparable
to PSO duties; (2) previous work experience conducting academic,
commercial, or government-sponsored protected species surveys; or (3)
previous work experience as a PSO; the PSO should demonstrate good
standing and consistently good performance of PSO duties.
For data collection purposes, PSOs shall use standardized data
collection forms, whether hard copy or electronic. PSOs shall record
detailed information about any implementation of mitigation
requirements, including the distance of animals to the acoustic source
and description of specific actions that ensued, the behavior of the
animal(s), any observed changes in behavior before and after
implementation of mitigation, and if shutdown was implemented, the
length of time before any subsequent ramp-up of the acoustic source. If
required mitigation was not implemented, PSOs should record a
description of the circumstances. At a minimum, the following
information must be recorded:
<bullet> Vessel names (source vessel and other vessels associated
with survey) and call signs;
<bullet> PSO names and affiliations;
<bullet> Dates of departures and returns to port with port name;
<bullet> Date and participants of PSO briefings;
<bullet> Dates and times (Greenwich Mean Time) of survey effort and
times corresponding with PSO effort;
<bullet> Vessel location (latitude/longitude) when survey effort
began and ended and vessel location at beginning and end of visual PSO
duty shifts;
<bullet> Vessel heading and speed at beginning and end of visual
PSO duty shifts and upon any line change;
<bullet> Environmental conditions while on visual survey (at
beginning and end of PSO shift and whenever conditions changed
significantly), including BSS and any other relevant weather conditions
including cloud cover, fog, sun glare, and overall visibility to the
horizon;
<bullet> Factors that may have contributed to impaired observations
during each PSO shift change or as needed as environmental conditions
changed (e.g., vessel traffic, equipment malfunctions); and
<bullet> Survey activity information, such as acoustic source power
output while in operation, number and volume of airguns operating in
the array, tow depth of the array, and any other notes of significance
(i.e., pre-start clearance, ramp-up, shutdown, testing, shooting, ramp-
up completion, end of operations, streamers, etc.).
The following information should be recorded upon visual
observation of any protected species:
<bullet> Watch status (sighting made by PSO on/off effort,
opportunistic, crew, alternate vessel/platform);
<bullet> PSO who sighted the animal;
<bullet> Time of sighting;
<bullet> Vessel location at time of sighting;
<bullet> Water depth;
<bullet> Direction of vessel's travel (compass direction);
<bullet> Direction of animal's travel relative to the vessel;
<bullet> Pace of the animal;
<bullet> Estimated distance to the animal and its heading relative
to vessel at initial sighting;
<bullet> Identification of the animal (e.g., genus/species, lowest
possible taxonomic level, or unidentified) and the composition of the
group if there is a mix of species;
<bullet> Estimated number of animals (high/low/best);
<bullet> Estimated number of animals by cohort (adults, yearlings,
juveniles, calves, group composition, etc.);
<bullet> Description (as many distinguishing features as possible
of each individual seen, including length, shape, color, pattern, scars
or markings, shape and size of dorsal fin, shape of head, and blow
characteristics);
<bullet> Detailed behavior observations (e.g., number of blows/
breaths, number of surfaces, breaching, spyhopping, diving, feeding,
traveling; as explicit and detailed as possible; note any observed
changes in behavior);
<bullet> Animal's closest point of approach (CPA) and/or closest
distance from any element of the acoustic source;
<bullet> Platform activity at time of sighting (e.g., deploying,
recovering, testing, shooting, data acquisition, other); and
<bullet> Description of any actions implemented in response to the
sighting (e.g., delays, shutdown, ramp-up) and time and location of the
action.
If a marine mammal is detected while using the PAM system, the
following information should be recorded:
<bullet> An acoustic encounter identification number, and whether
the detection was linked with a visual sighting;
<bullet> Date and time when first and last heard;
<bullet> Types and nature of sounds heard (e.g., clicks, whistles,
creaks, burst pulses, continuous, sporadic, strength of signal); and
<bullet> Any additional information recorded such as water depth of
the hydrophone array, bearing of the animal to the vessel (if
determinable), species or taxonomic group (if determinable),
spectrogram screenshot, and any other notable information.
Reporting
A report will be submitted to NMFS within 90 days after the end of
the cruise. The report will summarize the dates and locations of
seismic operations, and all marine mammal sightings (dates, times,
locations, activities, associated seismic survey activities), and
provide full documentation of methods, results, and interpretation
pertaining to all monitoring.
The draft report shall also include geo-referenced time-stamped
vessel tracklines for all time periods during which airguns were
operating. Tracklines should include points recording any change in
airgun status (e.g., when the airguns began operating, when they were
turned off, or when they changed from full array to single gun or vice
versa). GIS files shall be provided in ESRI shapefile format and
include the UTC date and time, latitude in decimal degrees, and
longitude in decimal degrees. All coordinates shall be referenced to
the WGS84 geographic coordinate system. In addition to the report, all
raw observational data shall be made available to NMFS. The report must
summarize the data collected as described above and in the IHA. A final
report must be submitted within 30 days following resolution of any
comments on the draft report.
Reporting Injured or Dead Marine Mammals
Discovery of injured or dead marine mammals--In the event that
personnel involved in survey activities covered by the authorization
discover an injured or dead marine mammal, the L-DEO shall report the
incident to the Office of Protected Resources (OPR), NMFS and to the
NMFS Alaska Regional Stranding Coordinator as soon as feasible. The
report must include the following information:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
[[Page 37305]]
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> General circumstances under which the animal was
discovered.
Vessel strike--In the event of a ship strike of a marine mammal by
any vessel involved in the activities covered by the authorization, L-
DEO shall report the incident to OPR, NMFS and to the NMFS Alaska
Regional Stranding Coordinator as soon as feasible. The report must
include the following information:
<bullet> Time, date, and location (latitude/longitude) of the
incident;
<bullet> Vessel's speed during and leading up to the incident;
<bullet> Vessel's course/heading and what operations were being
conducted (if applicable);
<bullet> Status of all sound sources in use;
<bullet> Description of avoidance measures/requirements that were
in place at the time of the strike and what additional measure were
taken, if any, to avoid strike;
<bullet> Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, visibility) immediately preceding the
strike;
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Estimated size and length of the animal that was struck;
<bullet> Description of the behavior of the animal immediately
preceding and following the strike;
<bullet> If available, description of the presence and behavior of
any other marine mammals present immediately preceding the strike;
<bullet> Estimated fate of the animal (e.g., dead, injured but
alive, injured and moving, blood or tissue observed in the water,
status unknown, disappeared); and
<bullet> To the extent practicable, photographs or video footage of
the animal(s).
Actions To Minimize Additional Harm to Live-Stranded (or Milling)
Marine Mammals
In the event of a live stranding (or near-shore atypical milling)
event within 50 km of the survey operations, where the NMFS stranding
network is engaged in herding or other interventions to return animals
to the water, the Director of OPR, NMFS (or designee) will advise L-DEO
of the need to implement shutdown for all active acoustic sources
operating within 50 km of the stranding. Procedures related to
shutdowns for live stranding or milling marine mammals include the
following:
<bullet> If at any time, the marine mammal(s) die or are
euthanized, or if herding/intervention efforts are stopped, the
Director of OPR, NMFS (or designee) will advise L-DEO that the shutdown
around the animals' location is no longer needed.
<bullet> Otherwise, shutdown procedures will remain in effect until
the Director of OPR, NMFS (or designee) determines and advises L-DEO
that all live animals involved have left the area (either of their own
volition or following an intervention).
<bullet> If further observations of the marine mammals indicate the
potential for re-stranding, additional coordination with L-DEO will be
required to determine what measures are necessary to minimize that
likelihood (e.g., extending the shutdown or moving operations farther
away) and to implement those measures as appropriate.
Additional Information Requests--If NMFS determines that the
circumstances of any marine mammal stranding found in the vicinity of
the activity suggest investigation of the association with survey
activities is warranted, and an investigation into the stranding is
being pursued, NMFS will submit a written request to L-DEO indicating
that the following initial available information must be provided as
soon as possible, but no later than 7 business days after the request
for information:
<bullet> Status of all sound source use in the 48 hours preceding
the estimated time of stranding and within 50 km of the discovery/
notification of the stranding by NMFS; and
<bullet> If available, description of the behavior of any marine
mammal(s) observed preceding (i.e., within 48 hours and 50 km) and
immediately after the discovery of the stranding.
In the event that the investigation is still inconclusive, the
investigation of the association of the survey activities is still
warranted, and the investigation is still being pursued, NMFS may
provide additional information requests, in writing, regarding the
nature and location of survey operations prior to the time period
above.
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, our analysis applies to all species listed in
Table 1, given that NMFS expects the anticipated effects of the planned
geophysical survey to be similar in nature. Where there are meaningful
differences between species or stocks, or groups of species, in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, NMFS has identified species-specific factors to inform the
analysis.
As described above, we authorize only the takes estimated to occur
outside of Canadian territorial waters (Table 6); however, for the
purposes of our negligible impact analysis and determination, we
consider the total number of takes that are anticipated to occur as a
result of the entire survey (including the portion of the survey that
would occur within the Canadian territorial waters (approximately 13
percent of the survey) (Table 7).
[[Page 37306]]
Table 7--Total Estimated Take Including Canadian Territorial Waters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level B Level A
harassment harassment Level B Level A
(excluding (excluding harassment harassment Total Level B Total Level A
Species Canadian Canadian (Canadian (Canadian harassment harassment
territorial territorial territorial territorial
waters) waters) waters) waters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale............................... 2 0 0 0 2 0
Gray whale, WNP......................................... 2 0 1 0 3 0
Gray whale, ENP......................................... 1,448 45 666 16 2,114 61
Humpback whale.......................................... 403 14 165 4 568 18
Blue whale.............................................. 31 1 4 0 35 1
Fin whale............................................... 873 44 69 1 942 45
Sei whale............................................... 34 1 7 0 41 1
Minke whale............................................. 57 2 14 0 71 2
Sperm whale............................................. 131 0 22 0 153 0
Baird's beaked whale.................................... 29 0 2 0 31 0
Stejneger's beaked whale................................ 120 0 9 0 129 0
Cuvier's beaked whale................................... 114 0 9 0 123 0
Pacific white-sided dolphin............................. 1,374 0 191 0 1,565 0
Northern right whale dolphin............................ 927 0 451 0 1,378 0
Risso's dolphin......................................... 22 0 22 0 44 0
Killer whale............................................ 290 0 89 0 379 0
Dall's porpoise......................................... 5,661 178 1,825 36 7,486 214
Harbor porpoise......................................... 990 26 455 9 1,445 35
Northern fur seal....................................... 5,812 0 1,213 0 7,025 0
California sea lion..................................... 1,258 0 433 0 1,691 0
Steller sea lion, wDPS.................................. 54 0 46 0 100 0
Steller sea lion, eDPS.................................. 2,381 0 2,232 0 4,613 0
Northern elephant seal.................................. 6,850 0 1,429 0 8,279 0
Harbor seal............................................. 6,012 0 6,228 0 12,240 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
NMFS does not anticipate that serious injury or mortality would
occur as a result of L-DEO's planned survey, even in the absence of
mitigation, and none is authorized. Similarly, non-auditory physical
effects, stranding, and vessel strike are not expected to occur.
We are authorizing a limited number of instances of Level A
harassment of seven species (low- and high-frequency cetacean hearing
groups only) and Level B harassment only of the remaining marine mammal
species. However, we believe that any PTS incurred in marine mammals as
a result of the planned activity would be in the form of only a small
degree of PTS, not total deafness, because of the constant movement of
both the R/V Langseth and of the marine mammals in the project areas,
as well as the fact that the vessel is not expected to remain in any
one area in which individual marine mammals would be expected to
concentrate for an extended period of time. Since the duration of
exposure to loud sounds will be relatively short it would be unlikely
to affect the fitness of any individuals. Also, as described above, we
expect that marine mammals would likely move away from a sound source
that represents an aversive stimulus, especially at levels that would
be expected to result in PTS, given sufficient notice of the R/V
Langseth's approach due to the vessel's relatively low speed when
conducting seismic surveys. We expect that the majority of takes will
be in the form of short-term Level B behavioral harassment in the form
of temporary avoidance of the area or decreased foraging (if such
activity were occurring), reactions that are considered to be of low
severity and with no lasting biological consequences (e.g., Southall et
al., 2007, Ellison et al., 2012).
Marine mammal habitat may be impacted by elevated sound levels, but
these impacts would be temporary. Prey species are mobile and are
broadly distributed throughout the project areas; therefore, marine
mammals that may be temporarily displaced during survey activities are
expected to be able to resume foraging once they have moved away from
areas with disturbing levels of underwater noise. Because of the
relatively short duration (27 days) and temporary nature of the
disturbance, the availability of similar habitat and resources in the
surrounding area, the impacts to marine mammals and the food sources
that they utilize are not expected to cause significant or long-term
consequences for individual marine mammals or their populations.
The tracklines of this survey either traverse or are proximal to
critical habitat for the Mexico DPS of humpback whales and for Steller
sea lions, and to feeding BIAs for humpback whales in general
(including both the Hawaii and Mexico DPSs/Central North Pacific stock
whales that are anticipated to occur in the survey area). As described
previously, the survey area is near a feeding BIA for gray whales and
covers the gray whale migratory BIA. However, these BIAs would not be
affected as they are spatially and temporally separated, respectively,
from the survey.
Yazvenko et al. (2007) reported no apparent changes in the
frequency of feeding activity in Western gray whales exposed to airgun
sounds in their feeding grounds near Sakhalin Island. Goldbogen et al.
(2013) found blue whales feeding on highly concentrated prey in shallow
depths (such as the conditions expected within humpback feeding BIAs)
were less likely to respond and cease foraging than whales feeding on
deep, dispersed prey when exposed to simulated sonar sources,
suggesting that the benefits of feeding for humpbacks foraging on high-
density prey may outweigh perceived harm from the acoustic stimulus,
such as the seismic survey (Southall et al., 2016). Additionally, L-DEO
will shut down the airgun array upon observation of an aggregation of
six or more large whales, which would reduce impacts to cooperatively
foraging animals. For all habitats, no physical impacts to habitat are
anticipated from seismic activities. While SPLs of sufficient strength
have
[[Page 37307]]
been known to cause injury to fish and fish and invertebrate mortality,
in feeding habitats, the most likely impact to prey species from survey
activities would be temporary avoidance of the affected area and any
injury or mortality of prey species would be localized around the
survey and not of a degree that would adversely impact marine mammal
foraging. The duration of fish avoidance of a given area after survey
effort stops is unknown, but a rapid return to normal recruitment,
distribution and behavior is expected. Given the short operational
seismic time near or traversing important habitat areas, as well as the
ability of cetaceans and prey species to move away from acoustic
sources, NMFS expects that there would be, at worst, minimal impacts to
animals and habitat within these areas.
Critical habitat for Steller sea lions has been established at
three rookeries in southeast Alaska (Hazy Island, White Sisters Island,
and Forrester Island near Dixon Entrance), at several major haul-outs,
and including aquatic zones that extend 0.9 km seaward and air zones
extending 0.9 km above the rookeries. Steller sea lions occupy
rookeries and pup from late-May through early-July (NMFS. 2008),
indicating that L-DEO's survey is unlikely to impact important sea lion
behaviors in critical habitat. Impacts to Steller sea lions within
these areas, and throughout the survey area, as well as impacts to
other pinniped species, are expected to be limited to short-term
behavioral disturbance, with no lasting biological consequences.
Negligible Impact Conclusions
The survey would be of short duration (27 days of seismic
operations), and the acoustic ``footprint'' of the survey would be
small relative to the ranges of the marine mammals that would
potentially be affected. Sound levels would increase in the marine
environment in a relatively small area surrounding the vessel compared
to the range of the marine mammals within the survey area. Short term
exposures to survey operations are not likely to significantly disrupt
marine mammal behavior, and the potential for longer-term avoidance of
important areas is limited.
The mitigation measures are expected to reduce the number and/or
severity of takes by allowing for detection of marine mammals in the
vicinity of the vessel by visual and acoustic observers, and by
minimizing the severity of any potential exposures via shutdowns of the
airgun array. Based on previous monitoring reports for substantially
similar activities associated with NMFS-issued IHAs, we expect that the
mitigation will be effective in preventing, at least to some extent,
potential PTS in marine mammals that may otherwise occur in the absence
of the mitigation (although all authorized PTS has been accounted for
in this analysis).
NMFS concludes that exposures to marine mammal species and stocks
due to L-DEO's survey would result in only short-term (temporary and
short in duration) effects to individuals exposed, over relatively
small areas of the affected animals' ranges. Animals may temporarily
avoid the immediate area, but are not expected to permanently abandon
the area. Major shifts in habitat use, distribution, or foraging
success are not expected. NMFS does not anticipate the authorized take
to impact annual rates of recruitment or survival.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect the species or stock through
effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> The activity is temporary and of relatively short duration
(27 days);
<bullet> The anticipated impacts of the activity on marine mammals
would primarily be temporary behavioral changes due to avoidance of the
area around the survey vessel;
<bullet> The number of instances of potential PTS that may occur
are expected to be very small in number. Instances of potential PTS
that are incurred in marine mammals are expected to be of a low level,
due to constant movement of the vessel and of the marine mammals in the
area, and the nature of the survey design (not concentrated in areas of
high marine mammal concentration);
<bullet> The availability of alternate areas of similar habitat
value for marine mammals to temporarily vacate the survey area during
the survey to avoid exposure to sounds from the activity;
<bullet> The potential adverse effects on fish or invertebrate
species that serve as prey species for marine mammals from the survey
would be temporary and spatially limited, and impacts to marine mammal
foraging would be minimal; and
<bullet> The required mitigation measures, including visual and
acoustic monitoring and shutdowns are expected to minimize potential
impacts to marine mammals (both amount and severity).
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 required mitigation and
monitoring 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 than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
There are several stocks for which the estimated instances of take
appear high when compared to the stock abundance (Table 6), or for
which there is no currently accepted stock abundance estimate. These
include the fin whale, minke whale, sperm whale, three species of
beaked whale, four stocks of killer whales, harbor porpoise, and one
stock of harbor seal. However, when other qualitative factors are used
to inform an assessment of the likely number of individual marine
mammals taken, the resulting numbers are appropriately considered
small. We discuss these in further detail below.
For all other stocks (aside from those referenced above and
discussed below), the proposed take is less than one-third of the best
available stock abundance (recognizing that some of those takes may be
repeats of the same individual, thus rendering the actual percentage
even lower), and noting that we generally excluded consideration of
abundance information for British Columbia in considering the amount of
take relative to the best available stock abundance information.
The stock abundance estimates for the fin, minke, beaked, and sperm
whale stocks that occur in the survey area are unknown, according to
the latest SARs. The same is true for the harbor porpoise. Therefore,
we reviewed other scientific information in making our small numbers
determinations for these species. As noted previously, partial
[[Page 37308]]
abundance estimates of 1,233 and 2,020 minke whales are available for
shelf and nearshore waters between the Kenai Peninsula and Amchitka
Pass and for the eastern Bering Sea shelf, respectively. For the minke
whale, these partial abundance estimates alone are sufficient to
demonstrate that the proposed take number of 59 is of small numbers.
The same surveys produced partial abundance estimates of 1,652 and
1,061 fin whales, for the same areas, respectively. Considering these
two partial abundance estimates in conjunction with the British
Columbia abundance estimate of 329 whales produces a total partial
estimate of 3,042 whales for shelf and nearshore waters between the
Kenai Peninsula and Amchitka Pass, the eastern Bering Sea shelf, and
British Columbia. Given that the Northeast Pacific stock of fin whale's
range is described as covering the entire GOA and Bering Sea, we
reasonably assume that a total abundance estimate for the stock would
show that the take number proposed for authorization (917) is small. In
addition, for these stocks as well as for other stocks discussed below
whose range spans the GOA, given that the estimated take will take
place in a relatively small portion of the stock's range, it is likely
there would be repeat takes of a smaller number of individuals, and
therefore, the number of individual animals taken will be lower.
As noted previously, Kato and Miyashita (1998) produced an
abundance estimate of 102,112 sperm whales in the western North
Pacific. However, this estimate is believed to be positively biased. We
therefore refer to Barlow and Taylor (2005)'s estimate of 26,300 sperm
whales in the northeast temperate Pacific to demonstrate that the take
number of 136 is a small number. There is no abundance information
available for any Alaskan stock of beaked whale. However, the take
numbers are sufficiently small (ranging from 29-120) that we can safely
assume that they are small relative to any reasonable assumption of
likely population abundance for these stocks. As an example, we review
available abundance information for other stocks of Cuvier's beaked
whales, which is widely distributed throughout deep waters of all
oceans and is typically the most commonly encountered beaked whale in
its range. Where some degree of bias correction, which is critical to
an accurate abundance estimate for cryptic species like beaked whales,
is incorporated to the estimate, we see typical estimates in the
thousands of animals, demonstrating that the authorized take numbers
are reasonably considered small. Current abundance estimates include
the Western North Atlantic stock (5,744 animals; CV = 0.36), the Hawaii
Pelagic stock (4,431 animals, CV = 0.41), and the California/Oregon/
Washington stock (3,274 animals; CV = 0.67).
For the southeast Alaska stock of harbor porpoise, whose range is
defined as from Dixon Entrance to Cape Suckling (including inland
waters), the SAR describes a partial abundance estimate, covering
inland waters but not coastal waters, totaling 1,354 porpoise. This
most recent abundance estimate is based on survey effort in inland
waters during 2010-12 (Dahlheim et al., 2015). An older abundance
estimate, based on survey effort conducted in 1997, covering both
coastal and inland waters of the stock's range, provides a more
complete abundance estimate of 11,146 animals (Hobbs and Waite, 2010).
This estimate is sufficient to demonstrate that the take number (1,016)
is small.
For the potentially affected stocks of killer whale, it would be
unreasonable to assume that all takes would accrue to any one stock.
Although the Gulf of Alaska, Aleutian Islands, and Bering Sea (GOA/
BSAI) transient stock could occur in southeast Alaska, it is unlikely
that any significant proportion of encountered whales would belong to
this stock, which is generally considered to occur mainly from Prince
William Sound through the Aleutian Islands and Bering Sea. Transient
killer whales in Canadian waters are considered part of the West Coast
transient stock, further minimizing the potential for encounter with
the GOA/BSAI transient stock. We assume that only nominal, if any, take
would actually accrue to this stock. Similarly, the offshore stock is
encountered only rarely compared with resident and transient stocks.
Seasonal sighting data collected in southeast Alaska waters between
1991 and 2007 shows a ratio of offshore and resident killer whale
sightings of 0.05 (Dahlheim et al., 2009), and it is unlikely that any
amount of take accruing to this stock would exceed small numbers. We
anticipate that most killer whales encountered would be transient or
resident whales. For the remaining stocks, we assume that take would
accrue to each stock in a manner roughly approximate to the stocks'
relative abundances, i.e., 78 percent Alaska resident, 12 percent West
Coast transient, and 10 percent northern resident. This would equate to
approximately 226 takes from the Alaska resident stock (9.6 percent of
the stock abundance); 35 takes from the West Coast transient stock (10
percent of the stock abundance), and 29 takes from the northern
resident stock (9.6 percent of the stock abundance). Based on the
assumptions described in this paragraph, we find that the authorized
taking is of no greater than small numbers for any stock of killer
whale.
If all authorized takes are allotted to each individual harbor seal
stock, the estimated instances of take would be greater than one-third
of the best available abundance estimate for the Sitka/Chatham Strait
stock of harbor seal. However, similar to the discussion provided above
for killer whale, it would be unreasonable to assume that all takes
would accrue to any one stock. Based on the location of the survey
relative to the potentially affected stocks' ranges, it is unlikely
that a significant proportion of the estimated takes would occur to the
Sitka/Chatham Strait stock (whose range just overlaps with the northern
extent of the survey area) (Muto et al., 2020). A majority of takes are
likely to accrue to the Dixon/Cape Decision stock, which most directly
overlaps with the survey area. In the unlikely event that all takes
occurred to the Dixon/Cape Decision stock, the amount of take would be
of small numbers.
Based on the analysis contained herein of the planned activity
(including the required mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS finds that small numbers of
marine mammals will be taken relative to the population size of the
affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
Marine mammals are legally hunted in Alaskan waters by coastal
Alaska Natives. In the GOA, the only marine mammals under NMFS'
jurisdiction that are currently hunted are Steller sea lions and harbor
seals. These species are an important subsistence resource for Alaska
Natives from southeast Alaska to the Aleutian Islands. There are
numerous communities along the shores of the GOA that participate in
subsistence hunting, including Juneau, Ketchikan, Sitka, and Yakutat in
southeast Alaska (Wolfe et al., 2013). According to Muto et al. (2019),
the annual subsistence take of Steller sea lions from the eastern stock
was 11, and 415 northern fur seals are taken annually. In addition, 340
harbor seals are taken annually (Muto et al. 2019). The seal harvest
throughout Southeast Alaska is generally highest during spring and
fall, but can occur any time of the year (Wolfe et al., 2013).
Given the temporary nature of the activities and the fact that most
[[Page 37309]]
operations would occur further from shore, the survey would not be
expected to have any impact on the availability of the species or
stocks for subsistence users. L-DEO conducted outreach to local
stakeholders, including subsistence communities, to notify subsistence
hunters of the planned survey, to identify the measures that would be
taken to minimize any effects on the availability of marine mammals for
subsistence uses, and to provide an opportunity for comment on these
measures. During operations, radio communications and Notice to
Mariners would keep interested parties apprised of vessel activities.
NMFS is unaware of any other subsistence uses of the affected marine
mammal stocks or species that could be implicated by this action. On
this basis, NMFS preliminarily determined that the total taking of
affected species or stocks would not have an unmitigable adverse impact
on the availability of such species or stocks for taking for
subsistence purposes, and requested comments or any information that
may help to inform this determination. We did not receive any comments
or additional information regarding potential impacts on the
availability of marine mammals for subsistence uses. Therefore, NMFS
has determined that the total taking of affected species or stocks
would not have an unmitigable adverse impact on the availability of
such species or stocks for taking for subsistence purposes.
National Environmental Policy Act
In compliance with the National Environmental Policy Act of 1969
(42 U.S.C. 4321 et seq.), as implemented by the regulations published
by the Council on Environmental Quality (40 CFR parts 1500-1508), the
National Science Foundation prepared an Environmental Analysis (EA) to
consider the direct, indirect, and cumulative effects to the human
environment from this geophysical survey of the Queen Charlotte Fault.
NSF's EA was made available to the public for review and comment in
relation to its suitability for adoption by NMFS in order to assess the
impacts to the human environment of issuance of an IHA to L-DEO. In
compliance with NEPA and the CEQ regulations, as well as NOAA
Administrative Order 216-6A, NMFS has reviewed the NSF's EA, determined
it to be sufficient, and adopted that EA and signed a Finding of No
Significant Impact (FONSI). NSF's EA is available at <a href="http://www.nsf.gov/geo/oce/envcomp/">www.nsf.gov/geo/oce/envcomp/</a>, and NMFS' FONSI is available at <a href="http://www.fisheries.noaa.gov/action/incidental-take-authorization-lamont-doherty-earth-observatory-geophysical-survey-queen">www.fisheries.noaa.gov/action/incidental-take-authorization-lamont-doherty-earth-observatory-geophysical-survey-queen</a>.
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 whenever we propose to authorize take for
endangered or threatened species.
On July 7, 2021, the NMFS Office of Protected Resources (OPR) ESA
Interagency Cooperation Division issued a Biological Opinion under
section 7 of the ESA, on the issuance of an IHA to L-DEO under section
101(a)(5)(D) of the MMPA by the NMFS OPR Permits and Conservation
Division. The Biological Opinion concluded that the proposed action is
not likely to jeopardize the continued existence of the sei whale, fin
whale, blue whale, sperm whale, Mexico DPS of humpback whale, western
North Pacific DPS of gray whale, North Pacific right whale, and western
DPS of Steller sea lion.
Authorization
As a result of these determinations, NMFS has issued an IHA to L-
DEO for conducting a marine geophysical survey of the Queen Charlotte
Fault beginning in July 2021, provided the previously mentioned
mitigation, monitoring, and reporting requirements are incorporated.
Dated: July 12, 2021.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2021-15046 Filed 7-14-21; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on July 15, 2021.
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