Notice2022-16809
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Marine Geophysical Surveys at the Cascadia Subduction Zone and Juan de Fuca Plate in the Northeast Pacific Ocean
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
August 5, 2022
Effective
August 1, 2022
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 Lamont-Doherty Earth Observatory (L-DEO) to incidentally harass, by Level B harassment only, marine mammals during geophysical surveys in the Northeast Pacific Ocean.
Full Text
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[Federal Register Volume 87, Number 150 (Friday, August 5, 2022)]
[Notices]
[Pages 47985-48000]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-16809]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC220]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Marine Geophysical Surveys at the
Cascadia Subduction Zone and Juan de Fuca Plate in the Northeast
Pacific Ocean
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
Lamont-Doherty Earth Observatory (L-DEO) to incidentally harass, by
Level B harassment only, marine mammals during geophysical surveys in
the Northeast Pacific Ocean.
DATES: This Authorization is effective from August 1, 2022 through July
31, 2023.
FOR FURTHER INFORMATION CONTACT: Kim Corcoran, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: https://
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-
[[Page 47986]]
take-authorizations-research-and-other-activities. In case of problems
accessing these documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental harassment 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 14, 2021, NMFS received a request from L-DEO for an IHA
to take marine mammals incidental to a marine geophysical survey off
the coasts of Oregon and Washington in the northeast Pacific Ocean. The
application was deemed adequate and complete on April 4, 2022. L-DEO
request is for take of small numbers of 23 species of marine mammals by
Level B harassment only. Neither L-DEO nor NMFS expects serious injury
or mortality to result from this activity and, therefore, an IHA is
appropriate.
NMFS previously issued an IHA to L-DEO for larger surveys in a
similar location in the Northeast Pacific (e.g., 86 FR 29090; May 28,
2021; 84 FR 35073; July 22, 2019). These surveys, however, included
survey areas much closer to the coast. L-DEO complied with all the
requirements (e.g., mitigation, monitoring, and reporting) of the
previous IHAs and information regarding their monitoring results may be
found in the Description of Marine Mammals in the Area of Specified
Activities section.
Description of Activity
Overview
Researchers from New Mexico Institute of Mining and Technology
(NMT) and Oregon State University (OSU), with funding from the U.S.
National Science Foundation (NSF) plan to conduct low-energy seismic
surveys from the Research Vessel (R/V) Marcus G. Langseth (Langseth),
which is owned and operated by Lamont-Doherty Earth Observatory (L-DEO)
of Columbia University, at the Cascadia subduction Zone and Juan de
Fuca Plate in the Northeast Pacific Ocean during Summer 2022. The two-
dimensional (2-D) seismic surveys will occur within the Exclusive
Economic Zone (EEZ) of the United States, in waters deeper than 1600
meters (m). To complete this survey, the R/V Langseth will tow a
Generator-Injector (GI)-airgun cluster consisting of two 45 cubic inch
(in\3\) GI guns spaced 2.46 m apart, with a total discharge volume of
90 in\3\. The acoustic source will be towed at 2 to 4 m deep along the
survey lines, while the receiving system is towed in an 800-1400 m long
hydrophone streamer.
Dates and Duration
The survey is expect to last for 23 days, with approximately six
days of seismic operations, three days of transit and 14 days of heat
flow measurements. R/V Langseth will leave out of and return to port in
Newport, OR, during summer 2022.
Specific Geographic Region
The survey will occur within ~42-47[deg] N, ~125-127[deg] W off the
coast of Washington and Oregon in the Northeast Pacific ocean. Four
regions where the surveys are to occur are depicted in Figure 1; the
tracklines could occur anywhere within the boxes shown in Figure 1. No
representative survey tracklines are shown, as actual track lines and
order of survey operations are dependent on science objectives and
weather. The surveys will occur within the EEZ of the U.S., in waters
>1600 m deep.
BILLING CODE P
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BILLING CODE C
A detailed description of the planned geophysical survey is
provided in the Federal Register notice for the proposed IHA (87 FR
37560; June 23, 2022). Since that time, no changes have been made to
the planned survey activities. Therefore, a detailed description is not
provided here. Please refer to that Federal Register notice for the
description of specified activity.
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 to the Federal Register on
June 23, 2022 (87 FR 37560). That notice described, in detail, L-DEO's
activity, the marine mammal species that may be affected by the
activity, and the
[[Page 47988]]
anticipated effects on marine mammals. During the 30-day public comment
period, NMFS did not receive any public comments.
Changes From the Proposed IHA to Final IHA
The addition of the requirement for the survey operator to provide
Protected Species Observers (PSOs) with a night-vision device suited
for the marine environment has been added for use during nighttime
ramp-up pre-clearance. This requirement was proposed by L-DEO in their
application, and has previously been required in recently issued IHAs
for similar surveys, but inadvertently left out of the notice of
proposed IHA and the draft IHA. There have been no other changes
between the proposed and final IHA.
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. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, incorporated here by reference, instead of
reprinting the information. 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="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species or stocks for which take is authorized
for this action, 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.
PBR is defined by the MMPA as the maximum number of animals, not
including natural mortalities, that may be removed from a marine mammal
stock while allowing that stock to reach or maintain its optimum
sustainable population (as described in NMFS' SARs). While no serious
injury or mortality is anticipated or authorized here, PBR and annual
serious injury and mortality from anthropogenic sources are included
here as gross indicators of the status of the species and other
threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprise that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Pacific SARs (Carretta et al., 2021). All values presented
in Table 1 are the most recent available at the time of publication and
are available in the 2020 SARs (Carretta et al., 2021) and draft 2021
SARs (available online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>).
Table 1--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeangliae. California/Oregon/ -,-,Y 4973 (0.05, 4776, 28.7 >48.6
Washington. 2018).
Minke whale..................... Balaenoptera California/Oregon/ -,-,N 915 (0.792, 509, 2018) 4.1 >0.59
acutorostrata. Washington.
Sei whale....................... Balaenoptera borealis.. Eastern North Pacific.. E, D, Y 519 (0.4, 374, 2014).. 0.75 >0.2
Fin whale....................... Balaenoptera physalus.. California/Oregon/ E, D, Y 11065 (0.405, 7,970, 80 >2.2
Washington. 2018).
Blue whale...................... Balaenoptera musculus.. Eastern North Pacific.. E, D, Y 1898 (0.085, 1767, 4.1 >19.4
2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
Sperm whale..................... Physeter macrocephalus. California/Oregon/ E, D, Y 1997 (0.57, 1270, 2.5 0.6
Washington. 2014).
Family Kogiidae:
Pygmy sperm whale............... Kogia breviceps........ California/Oregon/ -,-,N 4111 (1.12, 1924, 19 0
Washington. 2014).
Dwarf sperm whale............... Kogia sima............. California/Oregon/ -,-,N UNK (UNK, UNK, 2014).. UND 0
Washington.
Family Ziphiidae (beaked whales):
Baird's beaked whale............ Berardius Bairdii...... California/Oregon/ -,-,N 1363 (0.53, 894, 2018) 8.9 >0.2
Washington.
Cuvier's beaked whale........... Ziphius cavirostris.... California/Oregon/ -,-,N 3274 (0.67, 2059, 21 <0.1
Washington. 2014).
Mesoplodont Beaked Whales....... Mesoplodon spp......... California/Oregon/ -,-,N 3044 (0.54, 1967, 20 0.1
Washington. 2005).
Family Delphinidae:
Striped dolphin................. Stenella coeruleoalba.. California/Oregon/ -,-,N 29,988 (0.3, 23448, 225 >4
Washington. 2018).
Short-beaked common dolphin..... Delphinus delphis...... California/Oregon/ -,-,N 1,056,308 (0.21, 8889 >30.5
Washington. 888971, 2018).
Pacific white-sided dolphin..... Lagenorhynchus California/Oregon/ -,-,C 34,998 (0.222, 29090, 279 7
obliquidens. Washington. 2018).
Northern right whale dolphin.... Lissodelphis borealis.. California/Oregon/ -,-,N 29285 (0.72, 17024, 163 >6.6
Washington. 2018).
Risso's dolphin................. Grampus griseus........ California/Oregon/ -,-,N 6336 (0.32, 4817, 46 >3.7
Washington. 2014).
Killer whale: Orcinus orca........... West Coast Transient... -,-,N 349 (N/A, 349, 2018).. 3.5 0.4
North Pacific Offshore. -,-,N 300 (0.1, 276, 2012).. 2.8 0
Family Phocoenidae (porpoises):
[[Page 47989]]
Dall's porpoise................. Phocoenoides dalli..... California/Oregon/ -,-,N 16498 (0.61, 10286, 99 >0.66
Washington. 2019).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
Northern fur seal............... Callorhinus ursinus.... Eastern Pacific........ -,D,Y 626,618 (0.2, 530376, 11403 373
2020).
California...................... -,D,Y.................. 14050 (N/A, 7524, 2013) 451 1.8...................
Guadalupe fur seal.............. Arctocephalus townsendi Mexico................. T, D, Y 34187 (N/A, 31019, 1062 >3.8
2013).
Steller sea lion................ Eumetopias jubatus..... Eastern................ -,-,N 43201 (N/A, 2592 112
43201,2017).
California sea lion............. Zalophus californianus. United States.......... -,-,N 257606 (N/A, 233525, 14011 >320
2014).
Family Phocidae (earless seals):
Northern elephant seal.......... Mirounga angustirostris California Breeding.... -,-,N 187386 (N/A, 85369, 5122 5.3
2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
As indicated above, all 23 species (with 25 managed stocks) in
Table 1 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. All species that could
potentially occur in the planned survey areas are included in Table 3
of the IHA application.
A detailed description of the species likely to be affected by the
geophysical surveys, including brief introductions to the species and
relevant stocks as well as available information regarding population
trends and threats, and information regarding local occurrence, were
provided in L-DEO's IHA application and summarized in the Federal
Register notice for the proposed IHA (87 FR 37560; June 23, 2022);
since that time, we are not aware of any changes in the status of these
species and stocks; therefore detailed descriptions are not provided
here. Please refer to that Federal Register notice for these
descriptions. Please also refer to the NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for generalized species accounts.
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. 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, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). 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).
[[Page 47990]]
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, 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.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from L-DEO's survey activities have
the potential to result in behavioral harassment of marine mammals in
the vicinity of the survey area. The notice of proposed IHA (87 FR
37560; June 23, 2022) included a discussion of the effects of
anthropogenic noise on marine mammals and the potential effects of
underwater noise from L-DEO on marine mammals and their habitat. That
information and analysis is incorporated by reference into this final
IHA determination and is not repeated here; please refer to the notice
of proposed IHA (87 FR 37560; June 23, 2022).
Estimated Take
This section provides an estimate of the number of incidental takes
for authorization through this IHA, which will inform both NMFS'
consideration of ``small numbers'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes will be by Level B harassment only, primarily in
the form of behavioral disruption and including through Temporary
Threshold Shift (TTS) for low frequency cetaceans resulting from
exposure to sound from seismic airguns. TTS is not expected for all
other hearing groups and is considered to be unlikely for low frequency
cetaceans. Given the small size of the Level A harassment isopleths
(28.6 m for LF cetaceans and less than one meter for all other species)
and the anticipated effectiveness of the mitigation measures (i.e.,
shutdown, ramp-up, etc.) discussed in detail below in Mitigation
section, Level A harassment is neither anticipated nor to be
authorized.
As described previously, no serious injury or mortality is
anticipated or is authorized for this activity. Below we describe how
the take numbers are estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and (4) and
the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the take estimate.
Acoustic Thresholds
NMFS recommends the use of 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 or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa (rms) for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources.
L-DEO's survey includes the use of impulsive seismic sources (e.g.,
GI-airgun) and therefore the 160 dB re 1 [mu]Pa (rms) criteria is
applicable for analysis of Level B harassment.
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
survey includes the use of impulsive and intermittent sources.
For more information, see 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>.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The 2D survey will acquire data using a 2 GI-airgun cluster with a
total discharge volume of 90 in\3\ at a maximum tow depth of 2-4 m. L-
DEO model results are used to determine the 160 dB rms radius for the
2-GI airgun array in deep water (>1000 m) down to a maximum depth of
2000 m, as animals are generally not anticipated to dive below 2000 m
(Costa and Williams, 1999). Received sound levels for the two 45 in\3\
GI airguns have been predicted by L-DEO's model (Diebold et al., 2010)
as a function of distance from the airguns. This 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). In
addition, propagation measurements of pulses
[[Page 47991]]
from a 36-airgun array at a tow depth of 6 m have been reported in deep
water (~1600 m), intermediate water depth on the slope (~600-1100 m),
and shallow water (~50) in the Gulf of Mexico in 2007-2008 (Tolstoy et
al., 2009; Diebold et al., 2010).
For deep and intermediate-water cases, the field measurements
cannot be used readily to derive mitigation radii, as at those sites
the calibration hydrophone was located at a roughly constant depth of
350-500 m, which may not intersect all the sound pressure relevant
water depth (~2000 m) for marine mammals. At short ranges, where the
direct arrivals dominate and the effects of seafloor interactions are
minimal, the data recorded at the deep sites are suitable for
comparison with modeled levels at the depth of the calibration
hydrophone. At longer ranges, the comparison with the mitigation
model--constructed from the maximum SPL through the entire water column
at varying distances from the airgun array--is the most relevant.
In deep and intermediate-water depths, comparisons at short ranges
between sound levels for direct arrivals recorded by the calibration
hydrophone and model results for the same array tow depth are in good
agreement (Fig. 12 and 14 in Appendix H of L-DEO's PEIS). Consequently,
isopleths falling within this domain can be predicted reliably by the
L-DEO model, although they may be imperfectly sampled by measurements
recorded at a single depth. At greater distances, the calibration data
show that seafloor-reflected and sub-seafloor-refracted arrivals
dominate, whereas the direct arrivals become weak and/or incoherent.
Aside from local topography effects, the region around the critical
distance is where the observed levels rise closest to the mitigation
model curve. However, the observed sound levels are found to fall
almost entirely below the mitigation model curve. Thus, analysis of the
Gulf of Mexico calibration measurements demonstrate that although
simple, the L-DEO model is a robust tool for conservatively estimating
isopleths and the deep water radii obtained from model results down to
a maximum water depth of 2000 m.
A recent retrospective analysis of acoustic propagation of R/V
Langseth sources in a coastal/shelf environment from the Cascadia
Margin off Washington suggests that predicted (modeled) radii (using a
similar approach) for R/V Langseth sources were 2-3 times larger than
measured in shallow water (Crone et al., 2014). Similarly, data
collected by Crone et al. (2017) during a survey off New Jersey in 2014
and 2015 confirmed that in situ measurements and estimates of the 160-
and 180-dB distances collected by R/V Langseth hydrophone streamer were
2-3 times smaller than the predicted operational mitigation radii. Five
separate comparisons conducted of the L-DEO model with in situ received
level have confirmed that the L-DEO model generated conservative
mitigation zones, resulting in significantly larger zones.
The surveys will acquire data with two 45 in\3\ GI funs at a tow
depth of 2-4 m. As the entire survey occurs in deep water (>1000 m), L-
DEO used the deep-water radii obtained from the model results explained
above down to a maximum warter depth of 2000 m (see Figure A-1 in L-
DEO's application). The estimated distances to the Level B harassment
isopleth for the survey are shown in Table 3. The acoustic propagation
modeling methodologies are described in greater detail in L-DEO's IHA
application.
Table 3--Predicted Radial Distances to Isopleths Corresponding to the
Level B Harassment Threshold (160 dB re 1[mu]Pa (rms)).
------------------------------------------------------------------------
Predicted
distances (m) to a
Airgun configuration Water depth (m) received sound
level of 160 dB re
1 [mu]Parms
------------------------------------------------------------------------
Two 45-in\3\ GI guns............ >1000 553
------------------------------------------------------------------------
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 PGS 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 SEL<INF>cum</INF> (cumulative sound exposure
level) 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 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.
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 (micropascals ([mu]Pa)) in
order to integrate them over the entire broadband spectrum, resulting
in broadband weight 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 source velocities (2.32 m/s) and shot intervals (every
2.69 s) specific to the planned survey, potential radial distances to
auditory injury zones were then calculated for SEL<INF>cum</INF>
thresholds. Outputs from the User Spreadsheet in
[[Page 47992]]
the form of estimated distance to Level A harassment isopleths for the
survey are shown in Table 4. NMFS considers onset of PTS (Level A
harassment) to have occurred when either one of the dual metrics
(SEL<INF>cum</INF> and Peak<INF>flat</INF>) is exceeded (i.e., metric
resulting in the largest isopleth).
Table 4--Modeled Radial Distances (m) to Isopleths Corresponding to Level A Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zones (m)
Source (volume) ------------------------------------------------------------------------------------
LF MF HF Phocid Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
Two 45 cu in GI guns............................................... 28.6 0 0.1 0.3 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
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. NMFS continues to
develop ways to quantitatively refine these tools and will
qualitatively address the output where appropriate. For mobile sources,
such as the 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 for all species is unlikely to occur given the
small modeled zones of injury (estimated zone less than 30 m for low-
frequency cetaceans and near zero for all other species). Additionally,
animals are expected to have aversive/compensatory behavior in response
to the activity (Nachtigall et al., 2018) further limiting the
likelihood of auditory injury for all species. L-DEO did not request
authorization of take by Level A harassment, and no take by Level A
harassment authorized by NMFS.
Marine Mammal Occurrence
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information, which
will inform the take calculations.
The U.S. Navy (USN) primarily use the Southwest Fishery Science
Center (SWFSC) habitat-based cetacean density models to develop a
marine species density database for the Northwest Training and Testing
Study Area, which encompasses the survey area (USN 2019). For species
where density spatial modeling was unavailable, other data sources were
used. The USN marine species density database is currently the most
comprehensive density data set available for the California Current
Ecosystem (CCE) which encompasses waters off the coast of California,
Oregon, and Washington. However, GIS data layers are currently
unavailable for this database; thus, in this analysis the USN data were
only used for species for which density data were not available from an
alternative spatially-explicit model (i.e., minke, sei, and killer
whales, Kogia spp., and pinnipeds).
For most pinnipeds, L-DEO used the highest densities for spring,
summer, or fall from USN (2019), but corrected the estimates by
projecting the most recent population growth/updated population
estimates to 2022, when available. This same approach was used by NMFS
for previous L-DEO surveys (e.g., Northeast Pacific Ocean Survey (85 FR
19580; April 7, 2020)) in the region in 2021. For California sea lions,
spring densities from USN (2019) were used directly, the density for
the `40-70 km from shore' distance band was used for the Oregon survey
region, and the density for the `70-450 km from shore' distance band
was used for other survey regions. For the northern fur seal, the
density for the spring for the `up to 70 km from shore' distance band
was used for the Oregon survey region, and the spring density for the
`>130 km from shore' distance band was used for the other survey
regions. For the Guadalupe fur seal and Steller sea lion, summer
densities for the `200 m isobath to 300 km from shore' were used. For
the gray whale, the summer/fall density for the '10-47 km from shore'
distance band (USN 2019) was used for the Oregon survey region and a
density of zero was used for all other survey regions. For killer
whales, the annual density for all stocks occurring offshore was used
from USN (2019).
Spatially-explicit density data from summer/fall from the NOAA
CetSound website (NOAA 2022) were used for most other species (i.e.,
humpback, blue, fin, sperm, Baird's, beaked, and other small beaked
whales; striped, short-beaked common, Pacific white-sided, Risso's, and
northern right whale dolphins; and Dall's porpoise. CetMap (<a href="https://cetsound.noaa.gov/cda">https://cetsound.noaa.gov/cda</a>) provides output of summer/fall habitat-based
density models for cetaceans in the CCE (Becker et al., 2020) in the
form of GIS layers; these were used to calculate takes in the survey
area. The density estimates were available in the form of a GIS grid
with each cell in the grid measuring ~7 km east-west by 10 km north-
south. This grid was intersected with a GIS layer of the area expected
to be ensonified to >160 dB SPL from the survey area. North, west, and
south boundaries are based on overlap/intersection with geographic
extents of all four combined survey regions; eastern grid coverage
limit was defined by inclusion of cells that contained >25 percent
overlap with the angled boundary of the survey area polygon. The
densities from all grid cells overlapping the ensonified areas were
averaged to calculate an average species-specific density for each
species (Table 5).
Table 5--Modeled Marine Mammal Density Values and Daily Ensonified Area for L-DEO's Survey *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Daily
Species Density (#/km2) ensonified Number of Source
area (km2) seismic days
--------------------------------------------------------------------------------------------------------------------------------------------------------
LF Cetaceans:
Humpback whale.......................... 0.000464 221 6 Becker et al. (2020).
Blue whale.............................. 0.000226 221 6 Becker et al. (2020).
[[Page 47993]]
Fin whale............................... 0.00241 221 6 Becker et al. (2020).
Sei whale............................... 0.0004 221 6 USN (2019).
Minke whale............................. 0.0013 221 6 USN (2019).
MF Cetaceans:
Sperm whale............................. 0.002859 221 6 Becker et al. (2020).
Baird's beaked whale.................... 0.000407 221 6 Becker et al. (2020).
Small beaked whale...................... 0.002446 221 6 Becker et al. (2020).
Striped dolphin......................... 0.002095 221 6 Becker et al. (2020).
Short-beaked common dolphin............. 0.004845 221 6 Becker et al. (2020).
Pacific white-sided dolphin............. 0.059902 221 6 Becker et al. (2020).
Northern right-whale dolphin............ 0.049535 221 6 Becker et al. (2020).
Risso's dolphin......................... 0.009917 221 6 Becker et al. (2020).
Killer whale............................ 0.00092 221 6 USN (2019).
HF Cetaceans:
Pygmy/dwarf sperm whale................. 0.00163 221 6 USN (2019).
Dall's porpoise......................... 0.093613 221 6 Becker et al. (2020).
Otariid Seals:
Northern fur seal....................... * 0.036115/0.032983 221 6 USN (2019).
Guadalupe fur seal...................... 0.02945 221 6 USN (2019).
California sea lion..................... * 1.2951/0.0714 221 6 USN (2019).
Steller sea lion........................ 0.002573 221 6 USN (2019).
Phocid Seal:
Northern elephant seal.................. 0.043301 221 6 USN (2019).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Species in this table differ slightly from those included in L-DEO's application as NMFS has determined that their occurrence in the survey area is
rare and unlikely to be encountered. For more information, please see the Description of Marine Mammals in the Area of Specified Activity section of
this notice.
** Two different densities were used depending on water depth/distance from shore.
Take Estimation
Here we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and is authorized. In order to estimate the number of
marine mammals predicted to be exposed to sound levels that would
result in Level B harassment, radial distances from the airgun array to
the predicted isopleth corresponding to the 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 B
harassment threshold. The distance for the 160-dB threshold (based on
L-DEO model results) was used to draw a buffer around the area expected
to be ensonified (i.e., the survey area). The ensonified areas were
then increased by 25 percent to account for potential delays, which is
the equivalent to adding 25 percent to the line km to be surveyed. The
density for each species in Table 5 were then multiplied by the daily
ensonified areas expected to be ensonified, increased by 25 percent,
and then multiplied by the number of survey days (6) to estimate the
Level B takes.
The marine mammals predicted to occur within these respective
areas, based on the estimated densities, are assumed to be incidentally
taken. Estimated exposures for the survey are shown in Table 6.
Table 6--Estimated Take by Level B Harassment, and Percentage of Marine Mammal Stock Population
----------------------------------------------------------------------------------------------------------------
Estimated take Authorized
Species MMPA stock by Level B take by Level Stock Percent of
harassment B harassment abundance MMPA stock
----------------------------------------------------------------------------------------------------------------
Humpback whale \a\............ California/ 1 \d\ 2 4973 0.04
Oregon
Washington.
Blue whale.................... Eastern North 0 \d\ 2 1898 0.11
Pacific.
Fin whale..................... California/ 4 4 11,065 0.04
Oregon
Washington.
Sei whale..................... Eastern North 1 \d\ 2 519 0.39
Pacific.
Minke whale................... California/ 2 2 915 0.22
Oregon
Washington.
Sperm whale................... California/ 5 \d\ 7 1997 0.35
Oregon
Washington.
Baird's beaked whale.......... California/ 1 \d\ 9 1363 0.66
Oregon
Washington.
Small beaked whale \b\........ California/ 4 4 3044 0.13
Oregon
Washington.
Striped dolphin............... California/ 3 \d\ 46 29,988 0.15
Oregon
Washington.
Common dolphin................ California/ 8 \d\ 179 1,056,308 0.02
Oregon
Washington.
Pacific white-sided dolphin... California/ 99 99 34,998 0.28
Oregon
Washington.
Northern right-whale dolphin.. California/ 82 82 29,285 0.28
Oregon
Washington.
Risso's dolphin............... California/ 16 \d\ 22 6336 0.35
Oregon
Washington.
Killer whale.................. West Coast 2 \d\ 7 349 0.00
Transient.
North Pacific 300 0.00
Offshore.
Pygmy/dwarf sperm whale....... California/ 3 3 4111 0.07
Oregon
Washington.
Dall's porpoise............... California/ 155 155 16,498 0.94
Oregon
Washington.
[[Page 47994]]
Northern fur seal \c\......... Eastern Pacific. 17 17 626,618 0.00
California...... 530,376 0.00
Guadalupe fur seal............ Mexico.......... 49 49 34,187 0.14
California sea lion........... United States... 9 9 257,606 0.00
Steller sea lion.............. Eastern......... 4 4 43,201 0.01
Northern elephant seal........ California 62 62 5122 1.21
Breeding.
----------------------------------------------------------------------------------------------------------------
\a\ Takes are allocated among the three DPSs in the area based on Wade 2021 (Oregon: 42 percent Central America
DPS, 58 percent Mexico DPS; Washington: 6 percent Central America DPS, 25 percent Mexico DPS, 69 percent
Hawaii DPS).
\b\ Authorized takes include one each of Blainville's beaked whale, Stejneger's beaked whale, Cuvier's beaked
whale, and Hubbs' beaked whale (see Appendix B of L-DEO's application for more information).
\c\ In 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 authorized takes occurred within each stock.
\d\ Authorized take increased to mean group size from 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, NMFS
considers 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.
L-DEO reviewed mitigation measures employed during seismic research
surveys authorized by NMFS under previous incidental harassment
authorizations, as well as recommended best practices in Richardson et
al. (1995), Pierson et al. (1998), Weir and Dolman (2007), Nowacek et
al. (2013), Wright (2014), and Wright and Cosentino (2015), and has
required mitigation measures based on the above sources.
To reduce the potential for disturbance from acoustic stimuli
associated with the activities, L-DEO proposed to implement, and NMFS
requires, mitigation measures for marine mammals. Mitigation measures
that will be adopted during the planned survey include, but are not
limited to: (1) Vessel speed or course alteration, provided that doing
so will not compromise operation safety requirements. (2) GI-airgun
shut down within EZs, and (3) ramp-up procedures.
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 visually for the presence of marine mammals. The area to
be scanned visually includes primarily the exclusion zone, within which
observation of certain marine mammals requires shutdown of the acoustic
source, but also the buffer zone. The buffer zone means an area beyond
the exclusion zone to be monitored for the presence of marine mammals
that may enter the exclusion zone. During pre-start clearance (i.e.,
before ramp-up begins), the buffer zone also acts as an extension of
the exclusion zone in that observations of marine mammals within the
buffer zone will 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 100 m exclusion zone measured from the
edges of the airgun array. Visual monitoring of the exclusion zone 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-clearance, and (2)
during airgun use, aid in establishing and maintaining the exclusion
zone by altering the visual observer and crew of marine mammals that
are outside of, but may approach and enter, the exclusion zone.
L-DEO must use independent, dedicated, trained visual PSOs, meaning
that the PSOs must be employed by a third-party observer provider, must
not have tasks other than to conduct observational effort, collect
data, and communicate with and instruct relevant vessel crew with
regard to the presence of protected species and mitigation
requirements, and must have successfully completed an approved PSO
training course. PSO resumes shall be provided to NMFS for approval.
At least one visual PSO must have a minimum of 90 days at-sea
experience working in that role during a shallow penetration or low-
energy survey, with no more than 18 months elapsed since the conclusion
of the at-sea experience. One PSO with such experience shall be
designated as the lead for the entire
[[Page 47995]]
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 the 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 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) and 30 minutes prior to and during ramp-up of
the airgun array, including nighttime ramp-ups. Visual monitoring of
the exclusion and buffer zones must begin no less than 30 minutes prior
to ramp-up and must continue until one hour after use of the acoustic
source ceases or until 30 minutes past sunset. Visual PSOs must
coordinate to ensure 360 degree visual coverage around the vessel from
the most appropriate observation posts, and must 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) shall be communicated to
the operator to prepare for the potential shutdown of the acoustic
source.
During use of the airgun, detections of marine mammals within the
buffer zone (but outside the exclusion zone) should be communicated to
the operator to prepare for the potential shutdown of the acoustic
source.
PSOs may be on watch for a maximum of four 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.
Establishment of Exclusion and Buffer Zones
An exclusion zone (EZ) is a defined area within which occurrence of
a marine mammal triggers mitigation action intended to reduce the
potential for certain outcome, e.g., auditory injury, disruption of
critical behaviors. The PSOs will establish a minimum EZ with a 100 m
radius with an additional 100 m buffer zone (total of 200 m). The 200m
zone 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 100 m EZ, with additional 100 m buffer zone, 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 SPL), while also
providing a consistent, reasonably observable zone within which PSOs
would typically be able to conduct effective observational effort.
Additionally, a 100 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 100 m is regularly attainable for PSOs using the naked eye
during typical conditions.
An extended 500 m exclusion zone must be established for all beaked
whales, dwarf and pygmy sperm whales, killer whales, a large whale with
a calf, and groups of six or more large whales during all survey
effort. No buffer zone is required.
Pre-Clearance and Ramp-Up
Ramp-up (sometimes referred to as ``soft start'') is the gradual
and systematic increase of emitted sound levels from an airgun array.
Ramp-up will begin with one GI airgun 45 cu in first being activated,
followed by the second after 5 minutes. The intent of pre-clearance
observation (30 minutes) is to ensure no marine mammals are observed
within the buffer zone prior to the beginning of ramp-up. During pre-
clearance is the only time observations of marine mammals in the buffer
zone will prevent operations (i.e., the beginning of ramp-up). The
intent of ramp-up is to warn protected species 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 are activated and the full volume is achieve,
is required at all times as part of the activation of the acoustic
source. All operators must adhere to the following pre-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 PSOs time to monitor the exclusion and buffer zones for
30 minutes prior to the initiation of ramp-up (pre-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-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 applicable exclusion zone or the buffer zone during
the 30 minutes pre-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 Mysticetes and all other
odontocetes, including sperm whales, pygmy sperm whales, dwarf sperm
whales, beaked whales, pilot whales, killer whales, Risso's dolphin);
<bullet> PSOs must monitor the exclusion and buffer zones during
ramp-up, and ramp-up must cease and the source must be shut down upon
detection of a marine mammal within the applicable exclusion 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> 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 observation and no
detections of marine mammals have occurred within the applicable
exclusion zone. 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 is not required.
<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
watch.
[[Page 47996]]
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 exclusion zone. The operator must also
establish and 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 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 exclusion zone and/or (2) a
marine mammal (other than delphinids, see below) is detected and
localized within the applicable exclusion zone, 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.
Following a shutdown, airgun activity will not resume until the
marine mammal has clear the EZ. The animal will be considered to have
cleared the EZ if it is visually observed to have departed the EZ, or
it has not been seen within the EZ for 15 minutes in the case of small
odontocetes and pinnipeds, and 30 minutes for Mysticetes and all other
odontocetes, including sperm whales, beaked whales, pilot whales,
killer whales, and Risso's dolphin) with no further observation of the
marine mammal(s).
The shutdown requirement can be waived for small dolphins if an
individual is visually detected and localized within an exclusion zone.
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--
Delphinus, Stenella, and Lissodelphis.
We propose 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 will
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 delphinids (e.g., Barkaszi et al., 2012). 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
exclusion zone).
Upon implementation of shutdown, the source may be reactivated
after the marine mammal(s) has been observed exiting the applicable
exclusion zone (i.e., animal is not required to fully exit the buffer
zone where applicable) or following a clearance period (15 minutes for
small odontocetes and pinnipeds, and 30 minutes for mysticetes and all
other odontocetes, including sperm whales, beaked whales, pilot whales,
killer whales, and Risso's dolphin) with no further observation of the
marine mammal(s).
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 B harassment
zones.
Vessel Strike Avoidance
These measures apply to all vessels associated with the planned
survey activity; however, we note that 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. These measures include the following:
1. Vessel operators and crews must maintain a vigilant watch for
all marine mammals and slow down, stop their vessel, or alter course,
as appropriate and regardless of vessel size, to avoid striking any
marine mammal. A single marine mammal at the surface may indicate the
presence of submerged animals in the vicinity of the vessel; therefore,
precautionary measures should be exercised when an animal is observed.
A visual observer aboard the vessel must monitor a vessel strike
avoidance zone around the vessel (specific distances detailed below),
to ensure the potential for strike is minimized. Visual observers
monitoring the vessel strike avoidance zone can be either third-party
observers or crew members, but crew members responsible for these
duties must be provided sufficient training to distinguish marine
mammals from other phenomena and broadly to identify a marine mammal to
broad taxonomic group (i.e., as a large whale or other marine mammal);
2. Vessel speeds must be reduced to 10 knots (kn) (5.14 meters per
second (m/s)) or less when mother/calf pairs, pods, or large
assemblages of any marine mammal are observed near a vessel;
3. All vessels must maintain a minimum separation distance of 100 m
from large whales (i.e., sperm whales and all mysticetes);
4. All vessels must attempt to maintain a minimum separation
distance of 50 m from all other marine mammals, with an exception made
for those animals that approach the vessel; and
5. When marine mammals are sighted while a vessel is underway, the
vessel should 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
[[Page 47997]]
relevant separation distance, the vessel should reduce speed and shift
the engine to neutral, not engaging the engines until animals are clear
of the area. This recommendation does not apply to any vessel towing
gear.
Based on our evaluation of the applicant's proposed measures, 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.
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 while
conducting the activities. 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 three visual
PSOs will be based aboard the R/V 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> PSOs shall be independent, dedicated and trained and must
be employed by a third-party observer provider;
<bullet> PSOs shall have no tasks other than to conduct visual
observational effort, 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);
<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 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.
PSOs must use standardized data collection forms, whether hard copy
or electronic. PSOs must 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 name and call sign;
<bullet> PSO names and affiliations;
<bullet> Date and participants of PSO briefings (as discussed in
General Requirement);
<bullet> Dates of departure and return to port with port name;
<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
[[Page 47998]]
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 marine mammal:
<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.
Reporting
L-DEO must submit a draft comprehensive report to NMFS on all
activities and monitoring results within 90 days of the completion of
the survey or expiration of the IHA, whichever comes sooner. A final
report must be submitted within 30 days following resolution of any
comments on the draft report. The report will describe the operations
that were conducted and sightings of marine mammals near the
operations. The report will provide full documentation of methods,
results, and interpretation pertaining to all monitoring. The 90-day
report will summarize the dates and locations of seismic operations,
and all marine mammal sightings (dates, times, locations, activities,
associated seismic survey activities). The report will also include
estimates of the number and nature of exposures that occurred above the
harassment threshold based on PSO observations and including an
estimate of those that were not detected, in consideration of both the
characteristics and behaviors of the species of marine mammals that
affect detectability, as well as the environmental factors that affect
detectability.
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. 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 West Coast 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);
<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 West Coast
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 procedures for all active acoustic
sources operating within 50 km of the stranding. Shutdown procedures
for live stranding or milling marine mammals include the following: If
at any time, the marine mammal the marine mammal(s) die or are
euthanized, or if herding/intervention efforts are stopped, the
Director of OPR, NMFS (or designee) will advise the IHA-holder that the
shutdown around the animals' location is no longer needed. Otherwise,
shutdown procedures will remain in
[[Page 47999]]
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).
If further observations of the marine mammals indicate the
potential for re-stranding, additional coordination with the IHA-holder
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.
Reporting Species of Concern
To support NMFS's goal of improving our understanding of occurrence
of marine mammal species or stocks in the area (e.g., presence,
abundance, distribution, density), L-DEO will immediately report
observations of Southern Resident killer whales or North Pacific right
whales to OPR, NMFS. Although, the likelihood of encountering either
species is considered to be rare and unexpected.
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 impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), 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' 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 baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
To avoid repetition, the discussion of our analysis applies to all
the species listed in Table 6, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar, except where a species- or stock-specific discussion is
warranted. NMFS does not anticipate that serious injury or mortality
will occur as a result from low-energy surveys, even in the absence of
mitigation, and no serious injury or mortality is authorized. As
discussed in the Potential Effects of Specified Activities on Marine
Mammals and their Habitat section, non-auditory physical effects and
vessel strike are not expected to occur. NMFS expects that all
potential take will be in the form of Level B behavioral harassment in
the form of temporary avoidance of the area or decreased foraging (if
such activity was occurring), responses that are considered to be of
low severity, and with no lasting biological consequences (e.g.,
Southall et al., 2007, 2021). TTS is not expect for most hearing groups
(HF, MF, otariids and phocids) and is considered to be highly unlikely
for LF cetaceans. Even repeated Level B harassment of some small subset
of an overall stock is unlikely to result in any significant realized
decrease in viability for the affected individuals, and thus would not
result in any adverse impact to the stock as a whole. As described
above, Level A harassment is not expected to occur given the estimated
small size of the Level A harassment zones.
In addition to being temporary, the maximum expected Level B
harassment zone around the survey vessel is 553 m. Therefore, the
ensonified area surrounding the vessel is relatively small compared to
the overall distribution of animals in the area and their use of the
habitat. Feeding behavior is not likely to be significantly impacted as
prey species are mobile and are broadly distributed throughout the
survey area; 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 short duration (6 days) and temporary
nature of the disturbance and 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 entire U.S. West Coast within 47 km of the coast is a BIA for
migrating gray whale potential presence January to July and October to
December. The BIA for northbound gray whale migration is broken into
two phases, Phase A (within 8 km of shore) and Phase B (within 5 km of
shore), which are active from January to July and March to July,
respectively. The BIA for southbound migration includes waters within
10 km of shore and is active from October to March. All planned survey
areas are outside of all gray whale BIAs and no takes of gray whales
are authorized. There are also two humpback whale feeding BIAs
(Stonewall and Heceta Bank) adjacent to the survey area, however no
overlap occurs between the survey area and the BIAs. There are no
rookeries, mating or calving grounds known to be biologically important
to marine mammals within the survey area.
Critical habitat for the Mexico and Central America DPSs of
humpback whales has been established along the U.S. West Coast (86 FR
21082; May 5, 2021), and NMFS has expanded the Southern Resident killer
whale critical habitat to include coastal waters of Washington, Oregon,
and California (86 FR 41668; August 2, 2021). No part of L-DEO's
seismic survey will occur in or near these critical habitats.
[[Page 48000]]
No permanent hearing impairment (Level A harassment) is anticipated
nor authorized. Authorized takes of killer whales is expected to
comprise almost entirely of the West Coast Transient and/or North
Pacific Offshore stocks as Southern Resident killer whales are
typically confined to coastal and inland waters. Therefore take of
Southern Resident killer whales is unlikely given the far offshore
location of the survey, and no take of Southern Resident killer whales
is authorized.
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 any of the species or stocks
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
(6 days);
<bullet> The anticipated impacts of the activity on marine mammals
would be temporary behavioral changes due to avoidance of the area
around the vessel;
<bullet> No take by Level A harassment is authorized;
<bullet> The availability of alternative 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 is readily
abundant;
<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 mitigation measures, including visual, shutdowns, and
enhanced measures for areas of biological importance (e.g., additional
monitoring vessel, daylight operations only) 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 monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other 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.
The amount of take NMFS proposes to authorize is below one third of
the estimated stock abundance for all species (in fact, take of
individuals is less than ten percent of the abundance of the affected
stocks, see Table 6). This is likely a conservative estimate because we
assume all takes are of different individual animals, which is likely
not the case. Some individuals may be encountered multiple times in a
day, but PSOs will count them as separate individuals if they cannot be
identified.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals will be
taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks will not
have an unmitigable adverse impact on the availability of such species
or stocks for taking for subsistence purposes.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has determined
that this action qualifies to be categorically excluded from further
NEPA review.
Endangered Species Act
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, in this case with the ESA Interagency
Cooperation Division within NMFS' OPR.
The NMFS Office of Protected Resources 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 action is not likely to jeopardize the continued
existence of ESA-listed blue whales, fin whales, sei whales, sperm
whales, Central America DPS humpback whales, Mexico DPS Humpback
whales, and Guadalupe fur seals. There is no designated critical
habitat in the action area for any ESA-listed marine mammal species.
Authorization
As a result of these determinations, NMFS proposes to issue an IHA
to L-DEO for conducting geophysical surveys in the Northeast Pacific
Ocean during summer 2022, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated.
Dated: August 2, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2022-16809 Filed 8-4-22; 8:45 am]
BILLING CODE P
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