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, 47985-48000 [2022-16809]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 87, Number 150 (Friday, August 5, 2022)]
[Notices]
[Pages 47985-48000]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[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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[GRAPHIC] [TIFF OMITTED] TN05AU22.000

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; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these 
species (e.g., physical and behavioral descriptions) may be found on 
NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species 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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports).

                                              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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports. 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 (https://www.fisheries.noaa.gov/find-species) 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: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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 SELcum (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 SELcum 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 SELcum 
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 SELcum 
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 
(SELcum and Peakflat) 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 (https://cetsound.noaa.gov/cda) 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 SELcum 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:
     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);
     Ramp-ups shall be scheduled so as to minimize the time 
spent with the source activated prior to reaching the designated run-
in;
     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;
     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);
     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.
     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.
     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:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     Mitigation and monitoring effectiveness.

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:
     PSOs shall be independent, dedicated and trained and must 
be employed by a third-party observer provider;
     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);
     PSOs shall have successfully completed an approved PSO 
training course appropriate for their designated task (visual);
     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;
     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;
     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;
     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
     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:
     Vessel name and call sign;
     PSO names and affiliations;
     Date and participants of PSO briefings (as discussed in 
General Requirement);
     Dates of departure and return to port with port name;
     Dates and times (Greenwich Mean Time) of survey effort and 
times corresponding with PSO effort;
     Vessel location (latitude/longitude) when survey effort 
began and ended and vessel location at beginning and end of visual PSO 
duty shifts;
     Vessel heading and speed at beginning and end of visual 
PSO duty shifts and upon any line change;
     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;
     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
     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:
     Watch status (sighting made by PSO on/off effort, 
opportunistic, crew, alternate vessel/platform);
     PSO who sighted the animal;
     Time of sighting;
     Vessel location at time of sighting;
     Water depth;
     Direction of vessel's travel (compass direction);
     Direction of animal's travel relative to the vessel;
     Pace of the animal;
     Estimated distance to the animal and its heading relative 
to vessel at initial sighting;
     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;
     Estimated number of animals (high/low/best);
     Estimated number of animals by cohort (adults, yearlings, 
juveniles, calves, group composition, etc.);
     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);
     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);
     Animal's closest point of approach (CPA) and/or closest 
distance from any element of the acoustic source;
     Platform activity at time of sighting (e.g., deploying, 
recovering, testing, shooting, data acquisition, other); and
     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:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     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:
     Time, date, and location (latitude/longitude) of the 
incident;
     Vessel's speed during and leading up to the incident;
     Vessel's course/heading and what operations were being 
conducted (if applicable);
     Status of all sound sources in use;
     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;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, visibility) immediately preceding the 
strike;
     Species identification (if known) or description of the 
animal(s) involved;
     Estimated size and length of the animal that was struck
     Description of the behavior of the animal immediately 
preceding and following the strike;
     If available, description of the presence and behavior of 
any other marine mammals present immediately preceding the strike;
     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
     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:
     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
     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:
     No serious injury or mortality is anticipated or 
authorized;
     The activity is temporary and of relatively short duration 
(6 days);
     The anticipated impacts of the activity on marine mammals 
would be temporary behavioral changes due to avoidance of the area 
around the vessel;
     No take by Level A harassment is authorized;
     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;
     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
     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]
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