[Federal Register Volume 87, Number 88 (Friday, May 6, 2022)]
[Notices]
[Pages 27111-27131]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-09792]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB866]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Geophysical Surveys of the Guerrero 
Gap in the Eastern Tropical Pacific

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

ACTION: Notice; issuance of an incidental harassment authorization 
(IHA).

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, NMFS has issued an IHA to the 
Lamont-Doherty Earth Observatory (L-DEO) to incidentally harass marine 
mammals during geophysical surveys of the Guerrero Gap off the coast of 
Mexico in the Eastern Tropical Pacific.

DATES: This authorization is effective from May 2, 2022 through May 1, 
2023.

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

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed incidental harassment authorization is 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 August 21, 2021, NMFS received a request from L-DEO for an IHA 
to take marine mammals incidental to geophysical surveys of the 
Guerrero Gap off the coast of Mexico in the Eastern Tropical Pacific 
(ETP). The application was deemed adequate and complete on December 14, 
2021. L-DEO's request is for take of a small number of 30 species of 
marine mammals by Level B harassment and, for two of those species, by 
Level A harassment. NMFS published a notice of proposed IHA for public 
review and comment on January 12, 2022 (87 FR 1992). Neither L-DEO nor 
NMFS expects serious injury or mortality to result from this activity 
and, therefore, an IHA is appropriate.

Description of Planned Activity

    Researchers from L-DEO, University of Texas Institute of Geophysics 
(UTIG), and Northern Arizona University (NAU), with funding from the 
National Science Foundation (NSF), and in collaboration with 
researchers from the National Autonomous University of Mexico 
(Universidad Nacional Autonoma de Mexico or UNAM) and Kyoto University, 
plan to conduct high-energy seismic surveys from the research vessel 
(R/V) Marcus G. Langseth (Langseth) in and around the Guerrero Gap off 
western Mexico, in the ETP in the mid- to late-spring of 2022. The 
study uses two-dimensional (2-D) seismic surveying to quantify incoming 
plate hydration and examine the role of fluids on megathrust slip 
behavior in and around the Guerrero Gap of the Middle America Trench. 
L-DEO plans to conduct two different methods of seismic acquisition, 
multi-channel seismic (MCS) using a hydrophone streamer and refraction 
surveys using ocean bottom seismometers (OBSs). A total of 3,600 
kilometers (km) of transect lines would be surveyed (2,230 km of 2-D 
MCS reflection data and 1,370 km of OBS refraction data). Approximately 
62 percent of the total survey effort would be MCS surveys, with the 
remaining 38 percent using OBSs. The planned surveys use a 36-airgun 
towed array with a total discharge volume of ~6600 cubic inches (in\3\) 
as an acoustic source, acquiring return signals using both a towed 
streamer as well as OBSs. The total survey duration will be 
approximately 48 days, including approximately 20 days of seismic 
survey operations, 3 days of transit to and from the survey area, 19 
days for equipment deployment/recovery, and 6 days of contingency time 
for poor weather, etc.
    The majority of the 2-D seismic surveys would occur within the 
Exclusive Economic Zone (EEZ) of Mexico, including territorial seas, 
and a small portion would occur in International Waters. Approximately 
6 percent of the total survey effort would occur in Mexican territorial 
waters. Note that the MMPA does not apply in Mexican territorial 
waters. L-DEO is subject only to Mexican law in conducting that portion 
of the survey. However, NMFS has calculated the expected level of 
incidental take in the entire activity area (including Mexican 
territorial waters) as part of the analysis supporting our 
determination under the MMPA that the activity will have a negligible 
impact on the affected species or stocks (see Estimated Take and

[[Page 27112]]

Negligible Impact Analysis and Determination).
    A detailed description of the planned geophysical surveys is 
provided in the Federal Register notice for the proposed IHA (87 FR 
1992; January 12, 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 the specific activity.

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to L-DEO was published 
in the Federal Register on January 12, 2022 (87 FR 1992). That notice 
described, in detail, L-DEO's activity, the marine mammal species that 
may be affected by the activity, and the anticipated effects on marine 
mammals. During the 30-day public comment period, NMFS received comment 
letters from the Center for Biological Diversity (CBD), Whales of 
Guerrero, and the Sociedad Mexicana de Mastozoolog[iacute]a Marina, 
A.C. (SOMEMMA). The Sociedad Mexicana de Mastozoolog[iacute]a Marina's 
comment letter was written in support of and reiterated the 
recommendations in the Whales of Guerrero letter, and we therefore 
address their comments together.
    Comment 1: Whales of Guerrero and SOMEMMA highlighted the status of 
the endangered Central America Distinct Population Segment (DPS) of 
humpback whales. Whales of Guerrero noted that in addition to 
transiting through the survey area along their migratory route, 
humpback whales from the Central America DPS have been observed 
calving, nursing, resting, and breeding in the planned survey area 
between November and May. Citing their own research surveys, Whales of 
Guerrero recommended that seismic surveys not occur in the region 
between November 1 and May 1 to ensure minimal impact on the Central 
America DPS humpback whales.
    Response: As required under the MMPA, NMFS preliminarily determined 
that the mitigation measures in the proposed IHA set forth the means of 
effecting the least practicable impact on the species and its habitat. 
``Minimal impact''--which was not defined by the commenter--is not the 
standard that must be met through the prescription of mitigation 
requirements. However, in consideration of the data and maps provided 
by Whales of Guerrero in their comment letter, showing humpback whale 
presence concentrated in nearshore waters, and on review of its survey 
plans, L-DEO agreed that limiting surveys of nearshore tracklines to 
between May 1 and October 31 would be practicable. NMFS here defines 
``nearshore'' tracklines as those tracklines planned to occur in areas 
where humpback whale sightings (as provided by Whales of Guerrero in 
their comment letter) have been recorded during the migratory period 
(i.e., until May 1), or where the associated estimated Level B 
harassment area would overlap areas where humpback whale sightings have 
been recorded. This definition includes tracklines within approximately 
33.4 km of shore (i.e., the maximum reported distance from shore of 
humpback sightings in the area). For example, this definition includes 
the 264-km MCS and OBS trackline running parallel to shore off 
Guerrero, as well as all connector lines and portions of tracklines 
landward of that trackline (see Figure 1 of L-DEO's IHA application). 
NMFS has included this requirement in the final IHA.
    Comment 2: Whales of Guerrero and SOMEMMA noted that at least 16 
additional species of marine mammals occur in the survey area, 
including endangered species and species with limited data on abundance 
and status. Whales of Guerrero included a table of sightings of these 
species over the course of their research activities between 2014 and 
2021. Whales of Guerrero states that they have launched a 3-year, 6-
site land-based field survey to identify important and vulnerable 
nursing and resting sites for humpback whales in Guerrero and are 
seeking funds to undertake year-round environmental DNA (eDNA) 
collections to determine cetacean usage of Guerrero's waters, coupled 
with concurrent boat-based year-round surveys to refine current 
understanding of marine mammal species present in Guerrero. Until these 
studies have been completed, Whales of Guerrero states that it would be 
``irresponsible'' to approve seismic surveys in the region and that in-
depth, year-round research is required to determine species presence 
and habitat usage before seismic surveys can safely occur in the 
region.
    Response: All species referenced by Whales of Guerrero were 
included in the table of marine mammals that could occur in the region 
(Table 1) in the notice of proposed IHA (87 FR 1992; January 12, 2022) 
and in Table 1 of this notice. The abundance and status of all species 
in Table 1, as well as the potential effects of L-DEO's activities on 
these species, have been considered in our determinations. Whales of 
Guerrero did not provide any additional information on these species 
that would change our determinations. Additionally, we note that NMFS 
does not have the authority to approve the seismic surveys, only the 
take of marine mammals incidental to the seismic surveys. NMFS must 
grant incidental take authorizations if it can find, based on the best 
scientific information available, 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). While Whales 
of Guerrero referenced ongoing studies, these studies have not yet been 
completed and are not available for NMFS's consideration. The available 
information for all species referenced by Whales of Guerrero thus 
supports our required findings for authorizing the taking of marine 
mammals incidental to L-DEO's planned surveys.
    Comment 3: Whales of Guerrero and SOMEMMA stated that Guerrero 
lacks the infrastructure to support response to potential marine mammal 
strandings and mortality events. Whales of Guerrero further states that 
there is no year-round monitoring or stranding response team in place 
and the remote locations and difficulty in accessing much of the 
coastline would make it unlikely that live stranding events could be 
documented and responded to appropriately. Both organizations noted 
that scientists and stranding experts from SOMEMMA are planning a 
stranding network capacity-building workshop for Guerrero-based 
officials, scientists, and local stakeholders in summer of 2022. Whales 
of Guerrero recommended seismic surveys in the region not be approved 
until a region-wide stranding and monitoring support network is 
established.
    Response: As stated above, NMFS does not have the authority to 
approve the seismic surveys, only the take of marine mammals incidental 
to the surveys. We note that L-DEO has conducted seismic surveys around 
the world for decades, including in areas without dedicated stranding 
networks, and no mass strandings have been reported. As discussed in 
the notice of proposed IHA (87 FR 1992; January 12, 2022), stranding is 
not expected to result from L-DEO's surveys. In a review of possible 
stranding associations with seismic surveys, Castellote and Llorens 
(2016) noted one stranding event, involving two Cuvier's beaked whales, 
that was contemporaneous with and reasonably associated spatially with 
a seismic survey conducted by L-DEO. However, the event was not 
considered a ``true atypical mass stranding'' and the L-DEO

[[Page 27113]]

survey was not determined to be a cause of the stranding event. While 
we agree with the authors of that review in that lack of evidence 
should not be considered conclusive, it is clear that there is very 
little evidence that seismic surveys should be considered as posing a 
significant risk of acute harm to beaked whales or other mid-frequency 
cetaceans. Using the best available information, which does not suggest 
that stranding is a likely outcome of the planned surveys, NMFS has 
made the necessary findings and is authorizing the incidental take 
requested by L-DEO.
    Comment 4: Whales of Guerrero and SOMEMMA noted that Guerrero is an 
authorized whale watch state in Mexico, with 56 boats and 200 crew 
members participating in the whale watch industry. Whales of Guerrero 
stated that the whale watch industry and larger community depend on 
marine mammal ecotourism, and would be impacted, should the population 
of humpback whales, which calve, breed, and nurse in the region be 
harmed. The whale watch guide network requested that seismic surveys do 
not occur during whale migration season, as threats to whales and 
dolphins are a threat to their livelihood.
    Response: Again, NMFS does not have the authority to authorize 
seismic surveys and will not require L-DEO to change their planned 
survey timing to accommodate the whale watch industry. However, since 
L-DEO is required to limit its surveys of the ``nearshore'' tracklines 
(see definition above) between May 1 and October 31, when migrating 
humpbacks are expected to have transited through the area. NMFS has 
determined that L-DEO's planned surveys would have a negligible impact 
on all species, including the humpback whales that are of particular 
interest to the whale watch companies.
    Comment 5: Whales of Guerrero and SOMEMMA expressed concern that 
the surveys would harm the reputation of the region as environmentally 
protective, which would be financially damaging to the area. Both 
organizations requested L-DEO discuss the ``potentially harmful'' 
surveys with regional governmental officials and scientific 
organizations which are invested in a healthy marine ecology prior to 
conducting survey work in Guerrero.
    Response: This comment is outside the scope of our action. L-DEO 
conducted all necessary consultations with the Mexican government to 
obtain approval to operate in the area.
    Comment 6: The CBD stated that the proposed IHA does not include 
the best available science regarding humpback whales. The CBD stated 
that the proposed IHA says that both the threatened Mexico DPS and 
endangered Central America DPS may occur in the proposed survey area, 
while the CBD said that humpback whales that winter along the Pacific 
coast of southern Mexico off the states of Oaxaca and Guerrero are 
likely to be part of the Central America DPS, not the Mexico DPS.
    Response: The CBD is correct that the notice of proposed IHA (87 FR 
1992; January 12, 2022) stated that humpback whales from both the 
Central America DPS and Mexico DPS may occur in the survey area. The 
notice further states that due to the expected timing of the surveys 
(spring), most humpbacks from the Mexico DPS will have begun their 
migration north toward the feeding grounds off of the U.S. west coast 
and are likely to be outside of the survey area. Humpbacks from the 
Central America DPS will likely be migrating northward through the 
survey area at the time of the proposed survey. The notice stated that 
we assume that most humpback whales taken by the proposed survey 
activities will be from the Central America DPS. NMFS has used the best 
available science in assessing the likelihood of each DPS occurring in 
the survey area during the planned surveys, and CBD does not offer new 
or contradictory information.
    Comment 7: The CBD stated that NMFS overestimated the abundance of 
the humpback whale population that may be exposed to the surveys. The 
CBD referenced Wade (2021) which estimated the abundance of the Central 
America DPS of humpback whales to be 755 individuals, while Table 1 in 
the notice of proposed IHA gives an abundance estimate of the Central 
North Pacific stock of humpback whales as 10,103 individuals. The CBD 
asserts that the Central North Pacific stock of humpback whales is the 
wrong stock for the area.
    Response: As noted by the CBD in previous comment letters (e.g., 86 
FR 29090; May 28, 2021), the designated stocks of humpback whales under 
the MMPA do not neatly align with the ESA-designated DPSs. Some 
humpback whales from the Mexico and Central America DPSs may be part of 
the Central North Pacific stock, and some may be part of the 
California/Oregon/Washington stock, which has an estimated abundance of 
4,973 individuals (Carretta et al., 2021). The abundance of humpback 
whales used to assess the relative proportion of the population taken, 
which informs our small numbers determination, is the estimated 
population of humpbacks in the Pacific waters of Mexico (2,566 
individuals; Gerrodette and Palacios, 1996). NMFS has authorized a 
total of only 8 takes of humpback whales, which is considered small 
numbers relative to any of the aforementioned abundance estimates for 
each population.
    Comment 8: The CBD asserts that NMFS failed to adequately assess 
the impacts of the surveys on the Central America DPS of humpback 
whales. The CBD states that the surveys may disrupt breeding activity, 
which would have a potential individual effect (i.e., lowering the 
individual's reproductive fitness), and a population-level impact by 
decreasing the population's ability to grow and recover, referring to a 
paper cited by NMFS in the notice of proposed IHA (Cerchio et al., 
2014). The CBD recommended NMFS restrict the authorization to the 
summer months to minimize harm to humpback whales.
    Response: The paper referenced by the CBD (Cerchio et al., 2014) 
describes observations of humpback whales off the coast of Angola 
reducing their singing activity when exposed to noise from seismic 
surveys. However, the authors of that paper state that it is impossible 
to determine from the study whether the decrease in humpback whale 
singing would translate into detrimental effects on individuals or the 
population. The CBD does not provide any additional evidence to support 
its assertion that the effects of L-DEO's proposed activity would have 
population-level impacts, or to justify its assertion that the 
recommended temporal restriction is warranted under the MMPA. NMFS does 
not expect any impacts to the fitness of individual breeding humpback 
whales or the population as a whole, regardless of the prescribed 
mitigation. However, as described above, Whales of Guerrero informed 
NMFS that humpback whales have been observed breeding, calving, and 
nursing in the region throughout the spring. Based on the information 
provided by Whales of Guerrero, which showed that humpback whale 
occurrence in the survey area is generally concentrated in the 
nearshore waters, and confirmation on the measure's practicability, 
NMFS is adding a requirement to the IHA to limit L-DEO's survey of the 
``nearshore'' tracklines until after May 1, at which point all breeding 
humpback whales are expected to have left the area, through October 31, 
before breeding humpback whales are expected to return to the area. 
Therefore, any potential for impacts to the fitness of individual 
breeding humpback whales or the

[[Page 27114]]

population as a whole is further reduced.
    Comment 9: The CBD urged NMFS to use density estimates for waters 
in the area of the survey specifically, rather than in the greater 
Eastern Tropical Pacific.
    Response: The CBD did not provide any sources for site-specific 
density estimates of any species. Therefore, NMFS' utilization of the 
density estimates for the greater Eastern Tropical Pacific to estimate 
take as the best available science remains valid.
    Comment 10: The CBD stated that no one-time, one-year IHA renewal 
should be issued without an opportunity for public comment published in 
the Federal Register prior to issuance because the timing of the survey 
could result in much more severe impacts to Central America humpback 
whales if it interrupts more of their breeding season.
    Response: As described in the notice of proposed IHA (87 FR 1992; 
January 12, 2022), on a case-by-case basis, NMFS may issue a Renewal 
IHA following notice to the public providing an additional 15 days for 
public comments when (1) up to another year of identical or nearly 
identical activities as described in the Description of Proposed 
Activity section of the notice of proposed IHA is planned or (2) the 
activities as described in the Description of Proposed Activity section 
of the notice of proposed IHA would not be completed by the time the 
IHA expires and a Renewal would allow for completion of the activities 
beyond that described in the Dates section of this notice, provided 
specific conditions are met. All proposed Renewal IHAs are posted for 
public comment in the Federal Register. Additionally, all parties that 
commented on the initial proposed IHA are directly contacted to provide 
opportunity to submit additional comments. If L-DEO requests an IHA 
Renewal, NMFS will comply with all procedural requirements, including 
the 15-day public comment period and notification to the CBD. Any 
Renewal IHA issued to L-DEO would include the same mitigation 
requirements as the initial IHA, including the timing restrictions 
described in the Mitigation section of this notice.

Changes From the Proposed IHA to Final IHA

    No changes have been made to the survey equipment, tracklines, or 
objectives. The only change from the proposed to final IHA is the 
addition of a requirement to limit surveys of ``nearshore'' tracklines 
(see definition in the Comments and Responses section and in the 
Mitigation section of this notice) between May 1 and October 31.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species or stocks for which take is expected and 
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. For taxonomy, we follow Committee on Taxonomy (2021). PBR 
is defined by the MMPA as the maximum number of animals, not including 
natural mortalities, that may be removed from a marine mammal stock 
while allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS's SARs). While no mortality is 
anticipated or authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Pacific SARs. 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/draft-marine-mammal-stock-assessment-reports). Where available, 
abundance and status information is also presented for marine mammals 
in the Pacific waters of Mexico and/or the greater ETP region. Table 1 
denotes the status of species and stocks under the U.S. MMPA and ESA. 
We note also that the Guadalupe fur seal is classified as ``En peligro 
de extinci[oacute]n'' (in danger of extinction) under the Norma Oficial 
Mexicana NOM-059-SEMARNAT-2010 and all other marine mammal species 
listed in Table 1, with the exception of Longman's beaked whales and 
Deraniyagala's beaked whales, are listed as ``Sujetas a 
protecci[oacute]n especial'' (subject to special protection).

                                               Table 1--Marine Mammals That Could Occur in the Survey Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Stock abundance
                                                                     ESA/MMPA    (CV, Nmin, most                                    ETP         Mexico
         Common name            Scientific name        Stock         status;    recent abundance         PBR         Annual M/   abundance     Pacific
                                                                    strategic      survey) \2\                         SI \3\       \4\       abundance
                                                                    (Y/N) \1\                                                                    \5\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae
 (rorquals):
    Humpback Whale...........  Megaptera         Central N         -, -, Y      10,103 (0.3,      83...............         26        2,566  ...........
                                novaeangliae.     Pacific.                       7,890, 2006).
    Minke whale..............  Balaenoptera      N/A.............  -, -, N      N/A.............  N/A..............        N/A          115  ...........
                                acutorostrata.
    Bryde's whale............  Balaenoptera      Eastern Tropical  -, -, N      Unknown           Undetermined.....    Unknown       10,411          649
                                edeni.            Pacific.                       (Unknown,
                                                                                 Unknown, N/A).
    Sei whale................  Balaenoptera      Eastern N         E, D, Y      519 (0.4, 374,    0.75.............      >=0.2            0  ...........
                                borealis.         Pacific.                       2014).

[[Page 27115]]

 
    Fin whale................  Balaenoptera      N/A.............  E, D, Y      N/A.............  N/A..............        N/A          574          145
                                physalus.
    Blue whale...............  Balaenoptera      Eastern N         E, D, Y      1,898 (0.085,     4.1..............     >=19.4        1,415          773
                                musculus.         Pacific.                       1,767, 2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
    Sperm whale..............  Physeter          N/A.............  E, D, Y      N/A.............  N/A..............        N/A        4,145        2,810
                                macrocephalus.
Family Kogiidae:
    Dwarf Sperm Whale........  Kogia sima......  N/A.............  N/A          N/A.............  N/A..............        N/A   \6\ 11,200  ...........
Family Ziphiidae (beaked
 whales):
    Cuvier's Beaked Whale....  Ziphius           N/A.............  -, -, N      N/A.............  N/A..............        N/A   \7\ 20,000   \8\ 68,828
                                cavirostris.
    Longman's beaked whale...  Indopacetus       N/A.............  -, -, N      N/A.............  N/A..............        N/A        1,007  ...........
                                pacificus.
    Blainville's beaked whale  Mesoplodon        N/A.............  -, -, N      N/A.............  N/A..............        N/A   \9\ 25,300   \8\ 68,828
                                densirostris.
    Ginkgo-toothed beaked      M. ginkgodens...  N/A.............  -, -, N      N/A.............  N/A..............        N/A   \9\ 25,300   \8\ 68,828
     whale.
    Deraniyagala's beaked      M. hotaula......  N/A.............  -, -, N      N/A.............  N/A..............        N/A   \9\ 25,300   \8\ 68,828
     whale.
    Pygmy beaked whale.......  M. peruvianus...  N/A.............  -, -, N      N/A.............  N/A..............        N/A   \9\ 25,300   \8\ 68,828
Family Delphinidae:
    Risso's dolphin..........  Grampus griseus.  N/A.............  -, -, N      N/A.............  N/A..............        N/A      110,457       24,084
    Rough-toothed dolphin....  Steno             N/A.............  -, -, N      N/A.............  N/A..............        N/A      107,663       37,511
                                bredanensis.
    Common bottlenose dolphin  Tursiops          N/A.............  -, -, N      N/A.............  N/A..............        N/A      335,834       61,536
                                truncatus.
    Pantropical spotted        Stenella          N/A \10\........  -, D, N      N/A.............  N/A..............        N/A         \11\      146,296
     dolphin.                   attenuata.                                                                                        1,297,091
    Spinner dolphin..........  Stenella          N/A \10\........  -, D, N      N/A.............  N/A..............        N/A         \11\      186,906
                                longirostris.                                                                                     2,075,871
    Striped dolphin..........  Stenella          N/A.............  -, -, N      N/A.............  N/A..............        N/A      964,362      128,867
                                coeruleoalba.
    Short-beaked common        Delphinus         N/A.............  -, -, N      N/A.............  N/A..............        N/A    3,127,203      283,196
     dolphin.                   delphis.
    Fraser's dolphin.........  Lagenodelphis     N/A.............  -, -, N      N/A.............  N/A..............        N/A  \7\ 289,300  ...........
                                hosei.
    Short-finned pilot whale.  Globicephala      N/A.............  -, -, N      N/A.............  N/A..............        N/A         \12\        3,348
                                macrorhynchus.                                                                                      589,315
    Killer whale.............  Orcinus orca....  N/A.............  -, -, N      N/A.............  N/A..............        N/A    \7\ 8,500          852
    False killer whale.......  Pseudorca         N/A.............  -, -, N      N/A.............  N/A..............        N/A   \7\ 39,800  ...........
                                crassidens.
    Pygmy killer whale.......  Feresa attenuata  N/A.............  -, -, N      N/A.............  N/A..............        N/A   \7\ 38,900  ...........
    Melon-headed whale.......  Peponocephala     N/A.............  -, -, N      N/A.............  N/A..............        N/A   \7\ 45,400  ...........
                                electra.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals
 and sea lions):
    Guadalupe fur seal.......  Arctocephalus     Mexico..........  T, D, Y      34,187 (N/A,      1,062............      >=3.8  ...........  ...........
                                townsendi.                                       31,019, 2013).
    California sea lion......  Zalophus          U.S.............  -, -, N      257,606 (N/       14,011...........       >320      105,000  ...........
                                californianus.                                   A,233,515,
                                                                                 2014).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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/draft-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.
\4\ From NMFS (2015b) unless otherwise noted.
\5\ Pacific Mexico excluding the Gulf of California (from Gerrodette and Palacios (1996) unless otherwise noted).
\6\ Estimate for ETP is mostly for K. sima but may also include some K. breviceps (Wade and Gerrodette 1993).
\7\ Wade and Gerrodette 1993.
\8\ Abundance for all ziphiids.
\9\ This estimate for the ETP includes all species of the genus Mesoplodon.
\10\ Several stocks of these species, while not classified as such in the U.S. SARs, are considered depleted due to historical interactions with tuna
  fisheries in the area. Please see the notice of proposed IHA (87 FR 1992; January 12, 2022) for a discussion of these stocks.


[[Page 27116]]

    As indicated above, all 30 species (with six managed stocks) in 
Table 1 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur, and we have authorized 
it. As the planned survey lines are outside of the U.S. EEZ, they do 
not directly overlap with the defined ranges for most U.S. managed 
stocks (Carretta et al., 2021). For some species (e.g., Bryde's whale, 
Guadalupe fur seal; see Table 1), animals encountered during the 
surveys could be from a defined stock under the MMPA but most marine 
mammals in the survey area do not belong to any defined stock.
    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 1992; January 12, 2022). 
Additional information provided by Whales of Guerrero regarding 
seasonal presence of humpback whales is summarized in the Comments and 
Responses section above, and their full comment letter is available at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities. Since 
publication of the notice of proposed IHA, we are not aware of any 
changes in ESA or MMPA status of these species or stocks; therefore, 
detailed descriptions are not provided here. Please refer to that 
Federal Register notice and the IHA application for these descriptions. 
Please also refer to NMFS' website (www.nmfs.noaa.gov/pr/species/mammals/) 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. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 2.

                  Table 2--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, 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. 
30 marine mammal species (28 cetacean and two pinniped (both otariid) 
species) have the reasonable potential to co-occur with the planned 
survey activities. Please refer to Table 1. Of the cetacean species 
that may be present, six are classified as low-frequency cetaceans 
(i.e., all mysticete species), 20 are classified as mid-frequency 
cetaceans (i.e., all delphinid and ziphiid species and the sperm 
whale), and two are classified as high-frequency cetaceans (i.e., Kogia 
spp.).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from L-DEO's geophysical 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 1992; January 12, 2022) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from L-DEO's geophysical survey activities 
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 1992; 
January 12, 2022). The referenced information includes a summary and 
discussion of the ways that the specified activity may impact marine 
mammals and their habitat. Consistent with the analysis in our prior 
Federal Register notices for similar L-DEO surveys and after 
independently evaluating the analysis in L-DEO's application, we 
determine that the survey is likely to result in the takes described in 
the Estimated Take section of this document and that other forms of 
take are not expected to occur.
    The Estimated Take section later in this document includes a 
quantitative analysis of the number of individuals that are expected to 
be taken by this

[[Page 27117]]

activity. The Negligible Impact Analysis and Determination section 
considers the content of this section, the Estimated Take section, and 
the Mitigation section, to draw conclusions regarding the likely 
impacts of these activities on the reproductive success or survivorship 
of individuals and how those impacts on individuals are likely to 
impact marine mammal species or stocks.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes are primarily by Level B harassment, as use of 
seismic airguns has the potential to result in disruption of behavioral 
patterns for individual marine mammals. There is also some potential 
for auditory injury (Level A harassment) for mysticetes and high 
frequency cetaceans (i.e., Kogia spp.). The required mitigation and 
monitoring measures are expected to minimize the severity of such 
taking to the extent practicable. As described previously, no serious 
injury or mortality is anticipated or authorized for this activity. 
Below we describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
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 permanent threshold shift (PTS) of some 
degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 microPascal ([mu]Pa) root mean square 
(rms) for continuous (e.g., vibratory pile-driving, drilling) and above 
160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., seismic 
airguns) or intermittent (e.g., scientific sonar) sources.
    L-DEO's activity includes the use of impulsive seismic sources, and 
therefore the 160 dB re 1 [mu]Pa (rms) threshold is applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). L-DEO's planned seismic survey includes 
the use of impulsive (seismic airguns) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds *  (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW)..................  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
(Underwater)...........................   LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW).................  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
(Underwater)...........................   LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.

[[Page 27118]]

 
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The planned 2-D survey would acquire data using the 36-airgun array 
with a total discharge of 6,600 in\3\ at a maximum tow depth of 12 m. 
L-DEO model results are used to determine the 160-dBrms radius for the 
36-airgun array in deep water (>1,000 m) down to a maximum water depth 
of 2,000 m. Received sound levels were predicted by L-DEO's model 
(Diebold et al., 2010) which 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 from the 36-airgun array at a tow depth of 6 m have been 
reported in deep water (approximately 1600 m), intermediate water depth 
on the slope (approximately 600-1100 m), and shallow water 
(approximately 50 m) 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 Level A and Level B harassment 
isopleths, as at those sites the calibration hydrophone was located at 
a roughly constant depth of 350-500 m, which may not intersect all the 
SPL isopleths at their widest point from the sea surface down to the 
maximum relevant water depth for marine mammals of ~2,000 m. At short 
ranges, where the direct arrivals dominate and the effects of seafloor 
interactions are minimal, the data recorded at the deep and slope sites 
are suitable for comparison with modeled levels at the depth of the 
calibration hydrophone. At longer ranges, the comparison with the 
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 NSF-USGS, 2011). 
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 model curve. However, the observed sound levels are found to 
fall almost entirely below the model curve. Thus, analysis of the Gulf 
of Mexico calibration measurements demonstrates that although simple, 
the L-DEO model is a robust tool for conservatively estimating 
isopleths.
    For deep water (>1,000 m), L-DEO used the deep-water radii obtained 
from model results down to a maximum water depth of 2000 m. The radii 
for intermediate water depths (100-1,000 m) were derived from the deep-
water ones by applying a correction factor (multiplication) of 1.5, 
such that observed levels at very near offsets fall below the corrected 
mitigation curve (See Fig. 16 in Appendix H of NSF-USGS, 2011).
    L-DEO's modeling methodology is described in greater detail in 
their IHA application. The estimated distances to the Level B 
harassment isopleths for the array are shown in Table 4. Please note 
that no survey effort will occur in waters <100 m deep. The estimated 
isopleth distance specific to shallow water depths are provided for 
reference only.

         Table 4--Predicted Radial Distances to Isopleths Corresponding to Level B Harassment Threshold
----------------------------------------------------------------------------------------------------------------
                                                                                                      Level B
                        Source and volume                         Tow depth  (m)    Water depth     harassment
                                                                                        (m)          zone  (m)
----------------------------------------------------------------------------------------------------------------
36 airgun array; 6,600 in \3\...................................              12          >1,000       \1\ 6,733
                                                                                       100-1,000      \2\ 10,100
                                                                                        <100 \3\      \4\ 25,494
----------------------------------------------------------------------------------------------------------------
\1\ Distance based on L-DEO model results.
\2\ Distance is based on L-DEO model results with a 1.5 x correction factor between deep and intermediate water
  depths.
\3\ No survey effort will occur in waters <100 m deep.
\4\ Distance is based on empirically derived measurements in the Gulf of Mexico with scaling applied to account
  for differences in tow depth.

    Predicted distances to Level A harassment isopleths, which vary 
based on marine mammal hearing groups, were calculated based on 
modeling performed by L-DEO using the NUCLEUS source modeling software 
program and the NMFS User Spreadsheet, described below. The acoustic 
thresholds for impulsive sounds (e.g., airguns) contained in the 
Technical Guidance were presented as dual metric acoustic thresholds 
using both SELcum 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

[[Page 27119]]

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.
    The values for SELcum and peak SPL for the Langseth 
airgun arrays were derived from calculating the modified far-field 
signature. The far-field signature is often used as a theoretical 
representation of the source level. To compute the far-field signature, 
the source level is estimated at a large distance below the array 
(e.g., 9 km), and this level is back projected mathematically to a 
notional distance of 1 m from the array's geometrical center. However, 
when the source is an array of multiple airguns separated in space, the 
source level from the theoretical far-field signature is not 
necessarily the best measurement of the source level that is physically 
achieved at the source (Tolstoy et al., 2009). Near the source (at 
short ranges, distances <1 km), the pulses of sound pressure from each 
individual airgun in the source array do not stack constructively, as 
they do for the theoretical far-field signature. The pulses from the 
different airguns spread out in time such that the source levels 
observed or modeled are the result of the summation of pulses from a 
few airguns, not the full array (Tolstoy et al., 2009). At larger 
distances, away from the source array center, sound pressure of all the 
airguns in the array stack coherently, but not within one time sample, 
resulting in smaller source levels (a few dB) than the source level 
derived from the far-field signature. Because the far-field signature 
does not take into account the large array effect near the source and 
is calculated as a point source, the modified far-field signature is a 
more appropriate measure of the sound source level for distributed 
sound sources, such as airgun arrays. L-DEO used the acoustic modeling 
methodology as used for estimating Level B harassment distances with a 
small grid step of 1 m in both the inline and depth directions. The 
propagation modeling takes into account all airgun interactions at 
short distances from the source, including interactions between 
subarrays, which are modeled using the NUCLEUS software to estimate the 
notional signature and MATLAB software to calculate the pressure signal 
at each mesh point of a grid.
    In order to more realistically incorporate the Technical Guidance's 
weighting functions over the seismic array's full acoustic band, 
unweighted spectrum data for the Langseth's airgun array (modeled in 1 
Hz bands) was used to make adjustments (dB) to the unweighted spectrum 
levels, by frequency, according to the weighting functions for each 
relevant marine mammal hearing group. These adjusted/weighted spectrum 
levels were then converted to pressures ([mu]Pa) in order to integrate 
them over the entire broadband spectrum, resulting in broadband 
weighted source levels by hearing group that could be directly 
incorporated within the User Spreadsheet (i.e., to override the 
Spreadsheet's more simple weighting factor adjustment). Using the User 
Spreadsheet's ``safe distance'' methodology for mobile sources 
(described by Sivle et al., 2014) with the hearing group-specific 
weighted source levels, and inputs assuming spherical spreading 
propagation and information specific to the planned survey (i.e., the 
2.2 m/s source velocity and (worst-case) 50-m shot interval, equivalent 
to a repetition rate of 23.1 seconds), potential radial distances to 
auditory injury zones were then calculated for SELcum 
thresholds.
    Inputs to the User Spreadsheets in the form of estimated source 
levels are shown in Appendix A of L-DEO's application. User 
Spreadsheets used by L-DEO to estimate distances to Level A harassment 
isopleths for the airgun arrays are also provided in Appendix A of the 
application. Outputs from the User Spreadsheets in the form of 
estimated distances to Level A harassment isopleths for the survey are 
shown in Table 5. As described above, NMFS considers onset of PTS 
(Level A harassment) to have occurred when either one of the dual 
metrics (SELcum and Peak SPLflat) is exceeded 
(i.e., metric resulting in the largest isopleth). L-DEO plans to 
conduct two different methods of seismic acquisition, MCS using a 
hydrophone streamer (approximately 62 percent of the total survey 
effort) and refraction surveys using OBSs (approximately 38 percent of 
the total survey effort). The airguns would fire at a shot interval of 
50 m (repetition rate of 23 seconds) during MCS surveys and at a 400-m 
interval (repetition rate of 155 seconds) during refraction surveys to 
OBSs. The distances presented in Table 5 were calculated using the MCS 
survey inputs as using the 50-m shot interval provides more 
conservative distances than the 400-m shot interval.

        Table 5--Modeled Radial Distances (m) to Isopleths Corresponding to Level A Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
                                                                    Level A harassment zone (m)
        Source (volume)             Threshold    ---------------------------------------------------------------
                                                   LF cetaceans    MF cetaceans    HF cetaceans      Otariids
----------------------------------------------------------------------------------------------------------------
36-airgun array (6,600 in\3\).  SELcum..........           320.2               0             1.0               0
                                Peak............             8.9            13.9           268.3            10.6
----------------------------------------------------------------------------------------------------------------

    Note that because of some of the assumptions included in the 
methods used (e.g., stationary receiver with no vertical or horizontal 
movement in response to the acoustic source), isopleths produced may be 
overestimates to some degree, which will ultimately result in some 
degree of overestimation of Level A harassment. However, these tools 
offer the best way to predict appropriate isopleths when more 
sophisticated modeling methods are not available, and NMFS continues to 
develop ways to quantitatively refine these tools and will 
qualitatively address the output where appropriate. For mobile sources, 
such as the planned seismic survey, the User Spreadsheet predicts the 
closest distance at which a stationary animal would not incur PTS if 
the sound source traveled by the animal in a straight line at a 
constant speed.
    Auditory injury is unlikely to occur for mid-frequency cetaceans 
and otariid pinnipeds, given very small modeled zones of injury for 
those species (all estimated zones less than 15 m for mid-frequency 
cetaceans and otariid pinnipeds), in context of distributed source 
dynamics. The source level of the array is a theoretical definition 
assuming a point source and measurement in the far-field of the source 
(MacGillivray, 2006). As

[[Page 27120]]

described by Caldwell and Dragoset (2000), an array is not a point 
source, but one that spans a small area. In the far-field, individual 
elements in arrays will effectively work as one source because 
individual pressure peaks will have coalesced into one relatively broad 
pulse. The array can then be considered a ``point source.'' For 
distances within the near-field, i.e., approximately 2-3 times the 
array dimensions, pressure peaks from individual elements do not arrive 
simultaneously because the observation point is not equidistant from 
each element. The effect is destructive interference of the outputs of 
each element, so that peak pressures in the near-field will be 
significantly lower than the output of the largest individual element. 
Here, the relevant peak isopleth distances would in all cases be 
expected to be within the near-field of the array where the definition 
of source level breaks down. Therefore, actual locations within this 
distance of the array center where the sound level exceeds the relevant 
peak SPL thresholds would not necessarily exist. In general, Caldwell 
and Dragoset (2000) suggest that the near-field for airgun arrays is 
considered to extend out to approximately 250 m.
    In order to provide quantitative support for this theoretical 
argument, we calculated expected maximum distances at which the near-
field would transition to the far-field (Table 5). For a specific array 
one can estimate the distance at which the near-field transitions to 
the far-field by:
[GRAPHIC] [TIFF OMITTED] TN06MY22.025

with the condition that D >> [lambda], and where D is the distance, L 
is the longest dimension of the array, and [lambda] is the wavelength 
of the signal (Lurton, 2002). Given that [lambda] can be defined by:
[GRAPHIC] [TIFF OMITTED] TN06MY22.026

where f is the frequency of the sound signal and v is the speed of the 
sound in the medium of interest, one can rewrite the equation for D as:
[GRAPHIC] [TIFF OMITTED] TN06MY22.027

and calculate D directly given a particular frequency and known speed 
of sound (here assumed to be 1,500 meters per second in water, although 
this varies with environmental conditions).
    To determine the closest distance to the arrays at which the source 
level predictions in Table 5 are valid (i.e., maximum extent of the 
near-field), we calculated D based on an assumed frequency of 1 kHz. A 
frequency of 1 kHz is commonly used in near-field/far-field 
calculations for airgun arrays (Zykov and Carr, 2014; MacGillivray, 
2006; NSF and USGS, 2011), and based on representative airgun spectrum 
data and field measurements of an airgun array used on the Langseth, 
nearly all (greater than 95 percent) of the energy from airgun arrays 
is below 1 kHz (Tolstoy et al., 2009). Thus, using 1 kHz as the upper 
cut-off for calculating the maximum extent of the near-field should 
reasonably represent the near-field extent in field conditions.
    If the largest distance to the peak sound pressure level threshold 
was equal to or less than the longest dimension of the array (i.e., 
under the array), or within the near-field, then received levels that 
meet or exceed the threshold in most cases are not expected to occur. 
This is because within the near-field and within the dimensions of the 
array, the source levels specified in Appendix A of L-DEO's application 
are overestimated and not applicable. In fact, until one reaches a 
distance of approximately three or four times the near-field distance 
the average intensity of sound at any given distance from the array is 
still less than that based on calculations that assume a directional 
point source (Lurton, 2002). The 6,600-in\3\ airgun array planned for 
use during the planned survey has an approximate diagonal of 28.8 m, 
resulting in a near-field distance of 138.7 m at 1 kHz (NSF and USGS, 
2011). Field measurements of this array indicate that the source 
behaves like multiple discrete sources, rather than a directional point 
source, beginning at approximately 400 m (deep site) to 1 km (shallow 
site) from the center of the array (Tolstoy et al., 2009), distances 
that are actually greater than four times the calculated 140-m near-
field distance. Within these distances, the recorded received levels 
were always lower than would be predicted based on calculations that 
assume a directional point source, and increasingly so as one moves 
closer towards the array (Tolstoy et al., 2009). Given this, relying on 
the calculated distance (138.7 m) as the distance at which we expect to 
be in the near-field is a conservative approach since even beyond this 
distance the acoustic modeling still overestimates the actual received 
level. Within the near-field, in order to explicitly evaluate the 
likelihood of exceeding any particular acoustic threshold, one would 
need to consider the exact position of the animal, its relationship to 
individual array elements, and how the individual acoustic sources 
propagate and their acoustic fields interact. Given that within the 
near-field and dimensions of the array source levels would be below 
those assumed here, we believe exceedance of the peak pressure 
threshold would only be possible under highly unlikely circumstances.
    In consideration of the received sound levels in the near-field as 
described above, we expect the potential for Level A harassment of mid-
frequency cetaceans, otariid pinnipeds, and phocid pinnipeds to be de 
minimis, even before the likely moderating effects of aversion and/or 
other compensatory behaviors (e.g., Nachtigall et al., 2018) are 
considered. We do not believe that Level A harassment is a likely 
outcome for any mid-frequency cetacean, otariid pinniped, or phocid 
pinniped and have not authorized any Level A harassment for these 
species.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    L-DEO used habitat-based stratified marine mammal densities for 
summer for the ETP when available (Barlow et al., 2009), and densities 
for the ETP from NMFS (2015b) for all other species (Table 6). Barlow 
et al. (2009) used data from 16 NMFS Southwest Fisheries Science Center 
(SWFSC) ship-based cetacean and ecosystem assessment surveys between 
1986 and 2006 to develop habitat models to predict density for 15 
cetacean species in the ETP. Model predictions were then used in 
standard line-transect formulae to estimate density for each transect 
segment for each survey year. Predicted densities for each year were 
smoothed with geospatial methods to obtain a continuous grid of density 
estimates for the surveyed area in the ETP. These annual grids were 
then averaged to obtain a composite grid that represents our best 
estimates of cetacean density over the past 20 years in the ETP. The 
models developed by Barlow et al. (2009) have been incorporated into a 
web-based GIS software system developed by Duke University's Strategic 
Environmental Research and Development Program. The habitat-based 
density models consist of 100 km x 100 km grid cells. Densities in the 
grid cells that overlapped the survey area were averaged for each of 
the three water depth categories (shallow, intermediate, deep).
    The NMFS SWFSC also developed density estimates for species in the 
ETP that may be affected by their own

[[Page 27121]]

fisheries research activities (NMFS 2015b). These estimates were 
derived from abundance estimates using ship-based surveys of marine 
mammals in the ETP, as reported by Gerrodette et al. (2008). While the 
SWFSC developed volumetric density estimates (animals/km\3\) to account 
for typical dive depth of each species (0-200 m and >200 m), L-DEO used 
the area density (animals/km\2\) to represent expected density across 
all water depth strata.
    For the sei whale, for which NMFS (2015b) reported a density of 
zero, L-DEO used the spring density for Baja from U.S. Navy (2017b). No 
regional density estimates are available for Guadalupe fur seals in the 
ETP; therefore, NMFS (2015b) used the density of Guadalupe fur seals in 
the California Current Ecosystem (CCE) as a proxy. However, as the 
survey area is south of the typical range of Guadalupe fur seals (Ortiz 
et al., 2019), the density from the CCE is likely an overestimate. In 
the survey area, Guadalupe fur seals are extremely unlikely to occur in 
waters over the continental shelf under 2,000 m (T. Norris, pers. 
comm.). NMFS has therefore assumed that the density of Guadalupe fur 
seals in water depths under 2,000 m is zero animals per square km, and 
have retained the CCE density estimate for waters over 2,000 m deep 
(Table 6).

                        Table 6--Estimated Densities of Marine Mammals in the Survey Area
----------------------------------------------------------------------------------------------------------------
                                                                     Density (#/km\2\) in survey area
                                                        --------------------------------------------------------
                        Species                                                Intermediate
                                                           Shallow water     water (100-1,000      Deep water
                                                              (<100 m)              m)             (>1,000 m)
----------------------------------------------------------------------------------------------------------------
Humpback whale.........................................        \1\ 0.00013        \1\ 0.00013        \1\ 0.00013
Minke whale............................................        \1\ 0.00001        \1\ 0.00001        \1\ 0.00001
Bryde's whale..........................................       \2\ 0.000486       \2\ 0.000489       \2\ 0.000451
Fin whale..............................................        \1\ 0.00003        \1\ 0.00003        \1\ 0.00003
Sei whale..............................................        \3\ 0.00005        \3\ 0.00005        \3\ 0.00005
Blue whale.............................................        \2\ 0.00010        \2\ 0.00009        \2\ 0.00008
Sperm whale............................................        \1\ 0.00019        \1\ 0.00019        \1\ 0.00019
Cuvier's beaked whale..................................        \2\ 0.00105        \2\ 0.00106        \2\ 0.00107
Longman's beaked whale.................................        \1\ 0.00004        \1\ 0.00004        \1\ 0.00004
Mesoplodon spp.\4\.....................................        \2\ 0.00032        \2\ 0.00033        \2\ 0.00036
Risso's dolphin........................................        \1\ 0.00517        \1\ 0.00517        \1\ 0.00517
Rough-toothed dolphin..................................        \2\ 0.00880        \2\ 0.00891        \2\ 0.00945
Common bottlenose dolphin..............................        \2\ 0.04809        \2\ 0.04502        \2\ 0.03557
Pantropical spotted dolphin............................        \1\ 0.12263        \1\ 0.12263        \1\ 0.12263
Spinner dolphin (whitebelly)...........................        \2\ 0.00148        \2\ 0.00155        \2\ 0.00193
Spinner dolphin (eastern)..............................        \2\ 0.13182        \2\ 0.12989        \2\ 0.12791
Striped dolphin........................................        \2\ 0.02800        \2\ 0.02890        \2\ 0.03516
Short-beaked common dolphin............................        \2\ 0.04934        \2\ 0.04881        \2\ 0.04435
Fraser's dolphin.......................................        \1\ 0.01355        \1\ 0.01355        \1\ 0.01355
Short-finned pilot whale \5\...........................        \2\ 0.00346        \2\ 0.00344        \2\ 0.00382
Killer whale...........................................         \1\ 0.0004         \1\ 0.0004         \1\ 0.0004
False killer whale.....................................        \1\ 0.00186        \1\ 0.00186        \1\ 0.00186
Pygmy killer whale.....................................        \1\ 0.00183        \1\ 0.00183        \1\ 0.00183
Melon-headed whale.....................................        \1\ 0.00213        \1\ 0.00213        \1\ 0.00213
Kogia spp..............................................        \1\ 0.00053        \1\ 0.00053        \1\ 0.00053
Guadalupe fur seal.....................................                  0    \1\ \6\ 0.00741        \1\ 0.00741
California sea lion....................................        \1\ 0.16262        \1\ 0.16262              \7\ 0
----------------------------------------------------------------------------------------------------------------
\1\ Density in greater ETP (NMFS 2015b).
\2\ Density in planned survey area (Barlow et al., 2009).
\3\ Density for Baja (U.S. Navy 2017b).
\4\ Density for Mesoplodon species guild (Blainville's beaked whale, Gingko-toothed beaked whale, Deraniyagala's
  beaked whale, and pygmy beaked whale).
\5\ Density for Globicephala species guild.
\6\ Density is assumed to be zero in waters <2,000 m.
\7\ Density is assumed to be zero in deep water (>1,000 m).

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    In order to estimate the number of marine mammals predicted to be 
exposed to sound levels that would result in Level A or Level B 
harassment, radial distances from the airgun array to predicted 
isopleths corresponding to the Level A harassment and Level B 
harassment thresholds are calculated, as described above. Those radial 
distances are then used to calculate the area(s) around the airgun 
array predicted to be ensonified to sound levels that exceed the Level 
A and Level B harassment thresholds. L-DEO identified specific seismic 
survey trackline(s) that could be surveyed on one day of research; in 
this case, a representative 182-km MCS line and a 222-km long OBS line 
were chosen. The distances to the 160-dB Level B harassment threshold 
and PTS (Level A harassment) thresholds (based on L-DEO model results) 
were used to draw a buffer around every transect line in GIS to 
determine the daily ensonified area in each depth category. The 
ensonified areas were then multiplied by the number of survey days (7 
days for OBS survey effort; 13 days for MCS survey effort) increased by 
25 percent. As noted previously, L-DEO has added 25 percent in the form 
of operational days, which is equivalent to adding 25 percent to the 
planned line kilometers to be surveyed. This accounts for the 
possibility that additional operational days are required, but likely 
results in an overestimate of actual exposures. For additional details 
regarding calculations of ensonified area, please see Appendix D of L-
DEO's application. L-DEO's estimated incidents of exposure above Level 
A and Level B harassment criteria are presented in Table 7.

[[Page 27122]]

    As previously noted, NMFS does not have authority under the MMPA 
within the territorial seas of foreign nations (from 0-12 nmi (22.2 km) 
from shore), as the MMPA does not apply in those waters, and therefore 
does not authorize incidental take that may occur as a result of 
activities occurring within territorial waters. However, NMFS has still 
calculated the estimated level of incidental take in the entire 
activity area (including Mexican territorial waters) as part of the 
analysis supporting our determination under the MMPA that the activity 
will have a negligible impact on the affected species. The total 
estimated take in U.S. and Mexican waters is presented in Table 8 (see 
Negligible Impact Analysis and Determination).
    L-DEO generally assumed that their estimates of marine mammal 
exposures above harassment thresholds to equate to take and requested 
authorization of those takes. Those estimates in turn form the basis 
for our take authorization numbers. For the species for which NMFS does 
not expect there to be a reasonable potential for take by Level A 
harassment to occur, i.e., mid-frequency cetaceans and all pinnipeds, 
we have added L-DEO's estimated exposures above Level A harassment 
thresholds (and requests for take by Level A harassment) to their 
estimated exposures above the Level B harassment threshold to produce a 
total number of incidents of take by Level B harassment that is 
authorized. Estimated exposures and authorized take numbers are shown 
in Table 7.

                         Table 7--Estimated and Authorized Take by Level A and Level B Harassment, and Percentage of Population
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Estimated       Estimated      Authorized      Authorized         Total         Regional
                 Species                  takes by Level  takes by Level  takes by Level  takes by Level    authorized      population      Percent of
                                           B harassment    A harassment    B harassment    A harassment        take            size         population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale..........................               8               0               8               0               8       \a\ 2,566            0.31
Minke whale.............................               1               0           \b\ 2               0           \b\ 2             115            1.74
Bryde's whale...........................              27               1              27               1              28         \a\ 649            4.31
Fin whale...............................               2               0               2               0               2         \a\ 145            1.38
Sei whale...............................               3               0               3               0               3      \c\ 29,600            0.01
Blue whale..............................               5               0               5               0               5             773            0.65
Sperm whale.............................              12               0              12               0              12           2,810            0.43
Cuvier's beaked whale...................              69               0              69               0              69      \c\ 20,000            0.35
Longman's beaked whale..................               3               0               3               0               3       \c\ 1,007            0.30
Mesoplodon spp..........................              23               0              23               0              23      \c\ 25,300            0.09
Risso's dolphin.........................             327               1             328               0             328      \a\ 24,084            1.36
Rough-toothed dolphin...................             596               1             597               0             597      \a\ 37,511            1.59
Common bottlenose dolphin...............           2,268               6           2,274               0           2,274      \a\ 61,536            3.70
Pantropical spotted dolphin.............           7,973              15           7,988               0           7,988     \a\ 146,296            5.46
Spinner dolphin (whitebelly)............             121               0             121               0             121     \a\ 186,906            0.06
Spinner dolphin (eastern)...............           8,173              16           8,189               0           8,189     \a\ 186,906            4.38
Striped dolphin.........................           2,209               3           2,212               0           2,212     \a\ 128,867            1.72
Short-beaked common dolphin.............           2,812               6           2,818               0           2,818     \a\ 283,196            1.00
Fraser's dolphin........................             856               2             858               0             858     \c\ 289,300            0.30
Short-finned pilot whale................             244               0             244               0             244       \a\ 3,348            7.29
Killer whale............................              25               0              25               0              25         \a\ 852            2.93
False killer whale......................             118               0             118               0             118      \c\ 39,600            0.30
Pygmy killer whale......................             116               0             116               0             116      \c\ 38,900            0.30
Melon-headed whale......................             135               0             135               0             135      \c\ 45,400            0.30
Kogia spp...............................              33               1              33               1              34  \c\ \d\ 11,200            0.30
Guadalupe fur seal......................             415               1             416               0             416      \c\ 34,187            1.22
California sea lion.....................             349              16             365               0             365     \c\ 105,000            0.35
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Estimated population in Pacific waters of Mexico (Gerrodette and Palacios (1996)).
\b\ Authorized take increased to maximum group size.
\c\ Population in ETP or wider Pacific (NMFS 2015b).
\d\ Population of Kogia species guild.

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood,

[[Page 27123]]

scope, range). It further considers the likelihood that the measure 
will be effective if implemented (probability of accomplishing the 
mitigating result if implemented as planned), the likelihood of 
effective implementation (probability implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    In order to satisfy the MMPA's least practicable adverse impact 
standard, NMFS has evaluated a suite of basic mitigation protocols for 
seismic surveys that are required regardless of the status of a stock. 
Additional or enhanced protections may be required for species whose 
stocks are in particularly poor health and/or are subject to some 
significant additional stressor that lessens that stock's ability to 
weather the effects of the specified activities without worsening its 
status. We reviewed seismic mitigation protocols required or 
recommended elsewhere (e.g., HESS, 1999; DOC, 2013; IBAMA, 2018; Kyhn 
et al., 2011; JNCC, 2017; DEWHA, 2008; BOEM, 2016; DFO, 2008; GHFS, 
2015; MMOA, 2016; Nowacek et al., 2013; Nowacek and Southall, 2016), 
recommendations received during public comment periods for previous 
actions, and the available scientific literature. We also considered 
recommendations given in a number of review articles (e.g., Weir and 
Dolman, 2007; Compton et al., 2008; Parsons et al., 2009; Wright and 
Cosentino, 2015; Stone, 2015b). This exhaustive review and 
consideration of public comments regarding previous, similar activities 
has led to development of the protocols included here.

Vessel-Based Visual Mitigation Monitoring

    Visual monitoring requires the use of trained observers (herein 
referred to as visual protected species observers (PSOs)) to scan the 
ocean surface for the presence of marine mammals. The area to be 
scanned visually includes primarily the exclusion zone (EZ), within 
which observation of certain marine mammals requires shutdown of the 
acoustic source, but also a buffer zone and, to the extent possible 
depending on conditions, the surrounding waters. The buffer zone means 
an area beyond the EZ to be monitored for the presence of marine 
mammals that may enter the EZ. During pre-start clearance monitoring 
(i.e., before ramp-up begins), the buffer zone also acts as an 
extension of the EZ in that observations of marine mammals within the 
buffer zone would also prevent airgun operations from beginning (i.e., 
ramp-up). The buffer zone encompasses the area at and below the sea 
surface from the edge of the 0-500 m EZ, out to a radius of 1,000 m 
from the edges of the airgun array (500-1,000 m). This 1,000-m zone (EZ 
plus buffer) represents the pre-start clearance zone. Visual monitoring 
of the EZ and adjacent waters is intended to establish and, when visual 
conditions allow, maintain zones around the sound source that are clear 
of marine mammals, thereby reducing or eliminating the potential for 
injury and minimizing the potential for more severe behavioral 
reactions for animals occurring closer to the vessel. Visual monitoring 
of the buffer zone is intended to (1) provide additional protection to 
marine mammals that may be in the vicinity of the vessel during pre-
start clearance, and (2) during airgun use, aid in establishing and 
maintaining the EZ by alerting the visual observer and crew of marine 
mammals that are outside of, but may approach and enter, the EZ.
    L-DEO must use dedicated, trained, NMFS-approved PSOs. The PSOs 
must have no tasks other than to conduct observational effort, record 
observational data, and communicate with and instruct relevant vessel 
crew with regard to the presence of marine mammals and mitigation 
requirements. PSO resumes shall be provided to NMFS for approval.
    At least one of the visual and two of the acoustic PSOs (discussed 
below) aboard the vessel must have a minimum of 90 days at-sea 
experience working in those roles, respectively, with no more than 18 
months elapsed since the conclusion of the at-sea experience. One 
visual PSO with such experience must be designated as the lead for the 
entire protected species observation team. The lead PSO must 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 must be scheduled to be on duty with those PSOs 
with appropriate training but who have not yet gained relevant 
experience.
    During survey operations (e.g., any day on which use of the 
acoustic source is planned to occur, and whenever the acoustic source 
is in the water, whether activated or not), a minimum of two visual 
PSOs must be on duty and conducting visual observations at all times 
during daylight hours (i.e., from 30 minutes prior to sunrise through 
30 minutes following sunset). Visual monitoring of the pre-start 
clearance zone must begin no less than 30 minutes prior to ramp-up, and 
monitoring must continue until one hour after use of the acoustic 
source ceases or until 30 minutes past sunset. Visual PSOs must 
coordinate to ensure 360[deg] visual coverage around the vessel from 
the most appropriate observation posts, and shall conduct visual 
observations using binoculars and the naked eye while free from 
distractions and in a consistent, systematic, and diligent manner.
    PSOs must establish and monitor the exclusion and buffer zones. 
These zones must be based upon the radial distance from the edges of 
the acoustic source (rather than being based on the center of the array 
or around the vessel itself). During use of the acoustic source (i.e., 
anytime airguns are active, including ramp-up), detections of marine 
mammals within the buffer zone (but outside the EZ) must be 
communicated to the operator to prepare for the potential shutdown of 
the acoustic source. Visual PSOs must immediately communicate all 
observations to the on duty acoustic PSO(s), including any 
determination by the PSO regarding species identification, distance, 
and bearing and the degree of confidence in the determination. Any 
observations of marine mammals by crew members must be relayed to the 
PSO team. During good conditions (e.g., daylight hours; Beaufort sea 
state (BSS) 3 or less), visual PSOs must conduct observations when the 
acoustic source is not operating for comparison of sighting rates and 
behavior with and without use of the acoustic source and between 
acquisition periods, to the maximum extent practicable.
    Visual PSOs may be on watch for a maximum of 4 consecutive hours 
followed by a break of at least one hour between watches and may 
conduct a maximum of 12 hours of observation per 24-hour period. 
Combined observational duties (visual and acoustic but not at same 
time) may not exceed 12 hours per 24-hour period for any individual 
PSO.

Passive Acoustic Monitoring

    Acoustic monitoring means the use of trained personnel (sometimes 
referred to as passive acoustic monitoring (PAM) operators, herein 
referred to as acoustic PSOs) to operate PAM equipment to acoustically 
detect the presence of marine mammals. Acoustic monitoring involves 
acoustically detecting marine mammals regardless of distance from the 
source, as localization of animals may not always be possible. Acoustic 
monitoring is intended to further support visual monitoring (during

[[Page 27124]]

daylight hours) in maintaining an EZ around the sound source that is 
clear of marine mammals. In cases where visual monitoring is not 
effective (e.g., due to weather, nighttime), acoustic monitoring may be 
used to allow certain activities to occur, as further detailed below.
    PAM must take place in addition to the visual monitoring program. 
Visual monitoring typically is not effective during periods of poor 
visibility or at night, and even with good visibility, is unable to 
detect marine mammals when they are below the surface or beyond visual 
range. Acoustic monitoring can be used in addition to visual 
observations to improve detection, identification, and localization of 
cetaceans. The acoustic monitoring would serve to alert visual PSOs (if 
on duty) when vocalizing cetaceans are detected. It is only useful when 
marine mammals vocalize, but it can be effective either by day or by 
night, and does not depend on good visibility. It must be monitored in 
real time so that the visual observers can be advised when cetaceans 
are detected.
    The R/V Langseth must use a towed PAM system, which must be 
monitored by at a minimum one on duty acoustic PSO beginning at least 
30 minutes prior to ramp-up and at all times during use of the acoustic 
source. Acoustic PSOs may be on watch for a maximum of 4 consecutive 
hours followed by a break of at least one hour between watches and may 
conduct a maximum of 12 hours of observation per 24-hour period. 
Combined observational duties (acoustic and visual but not at same 
time) may not exceed 12 hours per 24-hour period for any individual 
PSO.
    Survey activity may continue for 30 minutes when the PAM system 
malfunctions or is damaged, while the PAM operator diagnoses the issue. 
If the diagnosis indicates that the PAM system must be repaired to 
solve the problem, operations may continue for an additional 5 hours 
without acoustic monitoring during daylight hours only under the 
following conditions:
     Sea state is less than or equal to BSS 4;
     No marine mammals (excluding delphinids) detected solely 
by PAM in the applicable EZ in the previous 2 hours;
     NMFS is notified via email as soon as practicable with the 
time and location in which operations began occurring without an active 
PAM system; and
     Operations with an active acoustic source, but without an 
operating PAM system, do not exceed a cumulative total of 5 hours in 
any 24-hour period.

Establishment of Exclusion and Pre-Start Clearance Zones

    An EZ is a defined area within which occurrence of a marine mammal 
triggers mitigation action intended to reduce the potential for certain 
outcomes, e.g., auditory injury, disruption of critical behaviors. The 
PSOs must establish a minimum EZ with a 500-m radius. The 500-m EZ must 
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 must be shut 
down.
    The pre-start clearance zone is defined as the area that must be 
clear of marine mammals prior to beginning ramp-up of the acoustic 
source, and includes the EZ plus the buffer zone. Detections of marine 
mammals within the pre-start clearance zone must prevent airgun 
operations from beginning (i.e., ramp-up).
    The 500-m EZ is intended to be precautionary in the sense that it 
would be expected to contain sound exceeding the injury criteria for 
all cetacean hearing groups, (based on the dual criteria of 
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 500-m EZ is 
expected to minimize the likelihood that marine mammals will be exposed 
to levels likely to result in more severe behavioral responses. 
Although significantly greater distances may be observed from an 
elevated platform under good conditions, we believe that 500 m is 
likely regularly attainable for PSOs using the naked eye during typical 
conditions. The pre-start clearance zone simply represents the addition 
of a buffer to the EZ, doubling the EZ size during pre-clearance.
    An extended EZ of 1,500 m must be enforced for all beaked whales 
and Kogia species. No buffer of this extended EZ is required.

Pre-Start Clearance and Ramp-Up

    Ramp-up (sometimes referred to as ``soft start'') means the gradual 
and systematic increase of emitted sound levels from an airgun array. 
Ramp-up begins by first activating a single airgun of the smallest 
volume, followed by doubling the number of active elements in stages 
until the full complement of an array's airguns are active. Each stage 
should be approximately the same duration, and the total duration must 
not be less than approximately 20 minutes. The intent of pre-start 
clearance observation (30 minutes) is to ensure no protected species 
are observed within the pre-clearance zone (or extended EZ, for beaked 
whales and Kogia spp.) prior to the beginning of ramp-up. During pre-
start clearance period is the only time observations of marine mammals 
in the buffer zone would prevent operations (i.e., the beginning of 
ramp-up). The intent of ramp-up is to warn marine mammals of pending 
seismic survey operations and to allow sufficient time for those 
animals to leave the immediate vicinity. A ramp-up procedure, involving 
a step-wise increase in the number of airguns firing and total array 
volume until all operational airguns are activated and the full volume 
is achieved, is required at all times as part of the activation of the 
acoustic source. All operators must adhere to the following pre-start 
clearance and ramp-up requirements:
     The operator must notify a designated PSO of the planned 
start of ramp-up as agreed upon with the lead PSO; the notification 
time must not be less than 60 minutes prior to the planned ramp-up in 
order to allow the PSOs time to monitor the pre-start clearance zone 
(and extended EZ) for 30 minutes prior to the initiation of ramp-up 
(pre-start clearance);
     Ramp-ups must 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-start clearance 
observations must be notified again immediately prior to initiating 
ramp-up procedures and the operator must receive confirmation from the 
PSO to proceed;
     Ramp-up may not be initiated if any marine mammal is 
within the applicable exclusion or buffer zone. If a marine mammal is 
observed within the pre-start clearance zone (or extended EZ, for 
beaked whales and Kogia species) during the 30 minute pre-start 
clearance period, ramp-up may not begin until the animal(s) has been 
observed exiting the zones or until an additional time period has 
elapsed with no further sightings (15 minutes for small odontocetes and 
pinnipeds, and 30 minutes for all mysticetes and all other odontocetes, 
including sperm whales, beaked whales, and large delphinids, such as 
killer whales);
     Ramp-up must begin by activating a single airgun of the 
smallest volume in the array and shall continue in stages by doubling 
the number of active elements at the commencement of each stage, with 
each stage of approximately the same duration. Duration must not be 
less than 20 minutes. The operator must

[[Page 27125]]

provide information to the PSO documenting that appropriate procedures 
were followed;
     PSOs must monitor the pre-start clearance zone (and 
extended EZ) during ramp-up, and ramp-up must cease and the source must 
be shut down upon detection of a marine mammal within the applicable 
zone. Once ramp-up has begun, detections of marine mammals within the 
buffer zone do not require shutdown, but such observation must be 
communicated to the operator to prepare for the potential shutdown;
     Ramp-up may occur at times of poor visibility, including 
nighttime, if appropriate acoustic monitoring has occurred with no 
detections in the 30 minutes prior to beginning ramp-up. Acoustic 
source activation may only occur at times of poor visibility where 
operational planning cannot reasonably avoid such circumstances;
     If the acoustic source is shut down for brief periods 
(i.e., less than 30 minutes) for reasons other than that described for 
shutdown (e.g., mechanical difficulty), it may be activated again 
without ramp-up if PSOs have maintained constant visual and/or acoustic 
observation and no visual or acoustic detections of marine mammals have 
occurred within the applicable EZ. For any longer shutdown, pre-start 
clearance observation and ramp-up are required. For any shutdown at 
night or in periods of poor visibility (e.g., BSS 4 or greater), ramp-
up is required, but if the shutdown period was brief and constant 
observation was maintained, pre-start clearance watch of 30 minutes is 
not required; and
     Testing of the acoustic source involving all elements 
requires ramp-up. Testing limited to individual source elements or 
strings does not require ramp-up but does require pre-start clearance 
of 30 min.

Shutdown

    The shutdown of an airgun array requires the immediate de-
activation of all individual airgun elements of the array. Any PSO on 
duty will have the authority to delay the start of survey operations or 
to call for shutdown of the acoustic source if a marine mammal is 
detected within the applicable EZ. The operator must also establish and 
maintain clear lines of communication directly between PSOs on duty and 
crew controlling the acoustic source to ensure that shutdown commands 
are conveyed swiftly while allowing PSOs to maintain watch. When both 
visual and acoustic PSOs are on duty, all detections must be 
immediately communicated to the remainder of the on-duty PSO team for 
potential verification of visual observations by the acoustic PSO or of 
acoustic detections by visual PSOs. When the airgun array is active 
(i.e., anytime one or more airguns is active, including during ramp-up) 
and (1) a marine mammal appears within or enters the applicable EZ and/
or (2) a marine mammal (other than delphinids, see below) is detected 
acoustically and localized within the applicable EZ, the acoustic 
source must be shut down. When shutdown is called for by a PSO, the 
acoustic source must be immediately deactivated and any dispute 
resolved only following deactivation. Additionally, shutdown must occur 
whenever PAM alone (without visual sighting), confirms presence of 
marine mammal(s) in the EZ. If the acoustic PSO cannot confirm presence 
within the EZ, visual PSOs must be notified but shutdown is not 
required.
    Following a shutdown, airgun activity must not resume until the 
marine mammal has cleared the EZ. The animal is considered to have 
cleared the EZ if it is visually observed to have departed the EZ 
(i.e., animal is not required to fully exit the buffer zone where 
applicable), or it has not been seen within the EZ for 15 minutes for 
small odontocetes and pinnipeds, or 30 minutes for all mysticetes and 
all other odontocetes, including sperm whales, beaked whales, Kogia 
species, and large delphinids, such as killer whales.
    The shutdown requirement is waived for small dolphins if an 
individual is detected within the EZ. As defined here, the small 
dolphin group is intended to encompass those members of the Family 
Delphinidae most likely to voluntarily approach the source vessel for 
purposes of interacting with the vessel and/or airgun array (e.g., bow 
riding). This exception to the shutdown requirement applies solely to 
specific genera of small dolphins (Delphinus, Lagenodelphis, 
Lissodelphis, Stenella, Steno, and Tursiops).
    We include this small dolphin exception because shutdown 
requirements for small dolphins under all circumstances represent 
practicability concerns without likely commensurate benefits for the 
animals in question. Small dolphins are generally the most commonly 
observed marine mammals in the specific geographic region and would 
typically be the only marine mammals likely to intentionally approach 
the vessel. As described above, auditory injury is extremely unlikely 
to occur for mid-frequency cetaceans (e.g., delphinids), as this group 
is relatively insensitive to sound produced at the predominant 
frequencies in an airgun pulse while also having a relatively high 
threshold for the onset of auditory injury (i.e., permanent threshold 
shift).
    A large body of anecdotal evidence indicates that small dolphins 
commonly approach vessels and/or towed arrays during active sound 
production for purposes of bow riding, with no apparent effect observed 
in those delphinoids (e.g., Barkaszi et al., 2012, Barkaszi and Kelly, 
2018). The potential for increased shutdowns resulting from such a 
measure would require the Langseth to revisit the missed track line to 
reacquire data, resulting in an overall increase in the total sound 
energy input to the marine environment and an increase in the total 
duration over which the survey is active in a given area. Although 
other mid-frequency hearing specialists (e.g., large delphinids) are no 
more likely to incur auditory injury than are small dolphins, they are 
much less likely to approach vessels. Therefore, retaining a shutdown 
requirement for large delphinids would not have similar impacts in 
terms of either practicability for the applicant or corollary increase 
in sound energy output and time on the water. We do anticipate some 
benefit for a shutdown requirement for large delphinids in that it 
simplifies somewhat the total range of decision-making for PSOs and may 
preclude any potential for physiological effects other than to the 
auditory system as well as some more severe behavioral reactions for 
any such animals in close proximity to the Langseth.
    Visual PSOs must use best professional judgment in making the 
decision to call for a shutdown if there is uncertainty regarding 
identification (i.e., whether the observed marine mammal(s) belongs to 
one of the delphinid genera for which shutdown is waived or one of the 
species with a larger EZ).
    L-DEO must implement shutdown if a marine mammal species for which 
take was not authorized, or a species for which authorization was 
granted but the takes have been met, approaches the Level A or Level B 
harassment zones. L-DEO must also implement shutdown if any large whale 
(defined as a sperm whale or any mysticete species) with a calf 
(defined as an animal less than two-thirds the body size of an adult 
observed to be in close association with an adult) and/or an 
aggregation of six or more large whales are observed at any distance.

Vessel Strike Avoidance

    Vessel operators and crews must maintain a vigilant watch for all 
protected species and slow down, stop their vessel, or alter course, as

[[Page 27126]]

appropriate and regardless of vessel size, to avoid striking any marine 
mammal. A visual observer aboard the vessel must monitor a vessel 
strike avoidance zone around the vessel (distances stated below). 
Visual observers monitoring the vessel strike avoidance zone may be 
third-party observers (i.e., PSOs) or crew members, but crew members 
responsible for these duties must be provided sufficient training to 
(1) distinguish marine mammals from other phenomena and (2) broadly to 
identify a marine mammal as a whale or other marine mammal.
    Vessel speeds must be reduced to 10 knots or less when mother/calf 
pairs, pods, or large assemblages of cetaceans are observed near a 
vessel.
    All vessels must maintain a minimum separation distance of 100 m 
from sperm whales and all other baleen whales.
    All vessels must, to the maximum extent practicable, attempt to 
maintain a minimum separation distance of 50 m from all other marine 
mammals, with an understanding that at times this may not be possible 
(e.g., for animals that approach the vessel).
    When marine mammals are sighted while a vessel is underway, the 
vessel must take action as necessary to avoid violating the relevant 
separation distance (e.g., attempt to remain parallel to the animal's 
course, avoid excessive speed or abrupt changes in direction until the 
animal has left the area). If marine mammals are sighted within the 
relevant separation distance, the vessel must reduce speed and shift 
the engine to neutral, not engaging the engines until animals are clear 
of the area. This does not apply to any vessel towing gear or any 
vessel that is navigationally constrained.
    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.

Operational Restrictions

    L-DEO has agreed to limit surveys of all ``nearshore'' tracklines 
(i.e., tracklines occurring in, or which are anticipated to result in 
ensonification above the Level B harassment threshold of, areas where 
humpback whale sightings have been recorded during the migratory 
period, e.g., the 264-km MCS and OBS trackline nearest and parallel to 
the shoreline, and all lines landward of that trackline) to between May 
1 and October 31. Offshore tracklines may be surveyed outside that date 
range. This is included as a requirement of the IHA.
    We have carefully evaluated the suite of mitigation measures 
described here and considered a range of other measures in the context 
of ensuring that we prescribe the means of effecting the least 
practicable adverse impact on the affected marine mammal species and 
stocks and their habitat. Based on our evaluation of the required 
measures, as well as other measures considered by NMFS described above, 
NMFS has determined that the mitigation measures provide the means of 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Mitigation Measures in Mexican Waters

    As stated previously, NMFS cannot authorize the incidental take of 
marine mammals in the territorial seas of foreign nations, as the MMPA 
does not apply in those waters. L-DEO is required to adhere to the 
mitigation measures described above while operating within the Mexican 
EEZ and International Waters. The requirements do not apply within 
Mexican territorial waters. Mexico may prescribe mitigation measures 
that would apply to survey operations within the Mexican EEZ and 
territorial waters but NMFS is currently unaware of any specific 
potential requirements. While operating within the Mexican EEZ but 
outside Mexican territorial waters, if mitigation requirements 
prescribed by NMFS differ from the requirements established under 
Mexican law, L-DEO must adhere to the most protective measure. For 
operations in Mexican territorial waters, L-DEO would implement 
measures required under Mexican law (if any). No new information is 
available on mitigation measures required under Mexican law.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
survey area. Effective reporting is critical both to compliance as well 
as ensuring that the most value is obtained from the required 
monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     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).
     Mitigation and monitoring effectiveness.

Vessel-Based Visual Monitoring

    As described above, PSO observations must take place during daytime 
airgun operations. During seismic survey operations, at least five 
visual PSOs must be based aboard the Langseth. Two visual PSOs must be 
on duty at all time during daytime hours. Monitoring must be conducted 
in accordance with the following requirements:
     The operator must provide PSOs with bigeye binoculars 
(e.g., 25 x 150; 2.7 view angle; individual ocular focus; height 
control) of appropriate quality (i.e., Fujinon or equivalent) solely 
for PSO use. These must be pedestal-mounted on the deck at the most 
appropriate vantage point that provides for optimal sea surface 
observation, PSO safety, and safe operation of the vessel; and
     The operator must work with the selected third-party 
observer provider to ensure PSOs have all equipment (including backup 
equipment) needed to adequately perform necessary tasks, including 
accurate determination of

[[Page 27127]]

distance and bearing to observed marine mammals.
    PSOs must have the following requirements and qualifications:
     PSOs must be independent, dedicated, trained visual and 
acoustic PSOs and must be employed by a third-party observer provider;
     PSOs must have no tasks other than to conduct 
observational effort (visual or acoustic), collect data, and 
communicate with and instruct relevant vessel crew with regard to the 
presence of protected species and mitigation requirements (including 
brief alerts regarding maritime hazards);
     PSOs must have successfully completed an approved PSO 
training course appropriate for their designated task (visual or 
acoustic). Acoustic PSOs are required to complete specialized training 
for operating PAM systems and are encouraged to have familiarity with 
the vessel with which they will be working;
     PSOs can act as acoustic or visual observers (but not at 
the same time) as long as they demonstrate that their training and 
experience are sufficient to perform the task at hand;
     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;
     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 1 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 must demonstrate good standing and 
consistently good performance of PSO duties.
    For data collection purposes, 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 must record a description 
of the circumstances. At a minimum, the following information must be 
recorded:
     Vessel names (source vessel and other vessels associated 
with survey) and call signs;
     PSO names and affiliations;
     Dates of departures and returns to port with port name;
     Date and participants of PSO briefings;
     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 of significance 
(i.e., pre-start clearance, ramp-up, shutdown, testing, shooting, ramp-
up completion, end of operations, streamers, etc.).
    The following information must be recorded upon visual observation 
of any protected species:
     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.
    If a marine mammal is detected while using the PAM system, the 
following information must be recorded:
     An acoustic encounter identification number, and whether 
the detection was linked with a visual sighting;
     Date and time when first and last heard;
     Types and nature of sounds heard (e.g., clicks, whistles, 
creaks, burst pulses, continuous, sporadic, strength of signal); and
     Any additional information recorded such as water depth of 
the hydrophone array, bearing of the animal to the vessel (if 
determinable), species or taxonomic group (if determinable), 
spectrogram screenshot, and any other notable information.

[[Page 27128]]

Reporting

    A report must be submitted to NMFS within 90 days after the end of 
the cruise. The report must summarize the dates and locations of 
seismic survey operations, and all marine mammal sightings (dates, 
times, locations, activities, associated seismic survey activities), 
and provide full documentation of methods, results, and interpretation 
pertaining to all monitoring.
    The draft report must also include geo-referenced time-stamped 
vessel tracklines for all time periods during which airguns were 
operating. Tracklines must 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 must be provided in ESRI shapefile format and include 
the UTC date and time, latitude in decimal degrees, and longitude in 
decimal degrees. All coordinates must be referenced to the WGS84 
geographic coordinate system. In addition to the report, all raw 
observational data must be made available to NMFS. The report must 
summarize the data collected as described above and in the IHA. A final 
report must be submitted within 30 days following resolution of any 
comments on the draft report.

Reporting Injured or Dead Marine Mammals

    Discovery of injured or dead marine mammals--In the event that 
personnel involved in survey activities covered by the authorization 
discover an injured or dead marine mammal, the L-DEO must 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 must 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 for all active acoustic sources 
operating within 50 km of the stranding. Procedures related to 
shutdowns for live stranding or milling marine mammals include the 
following:
     If at any time, the marine mammal(s) die or are 
euthanized, or if herding/intervention efforts are stopped, the 
Director of OPR, NMFS (or designee) will advise L-DEO that the shutdown 
around the animals' location is no longer needed.
     Otherwise, shutdown procedures will remain in effect until 
the Director of OPR, NMFS (or designee) determines and advises L-DEO 
that all live animals involved have left the area (either of their own 
volition or following an intervention).
     If further observations of the marine mammals indicate the 
potential for re-stranding, additional coordination with L-DEO will be 
required to determine what measures are necessary to minimize that 
likelihood (e.g., extending the shutdown or moving operations farther 
away) and to implement those measures as appropriate.
    Additional Information Requests--If NMFS determines that the 
circumstances of any marine mammal stranding found in the vicinity of 
the activity suggest investigation of the association with survey 
activities is warranted, and an investigation into the stranding is 
being pursued, NMFS will submit a written request to L-DEO indicating 
that the following initial available information must be provided as 
soon as possible, but no later than 7 business days after the request 
for information:
     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.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity,

[[Page 27129]]

duration), the context of any responses (e.g., critical reproductive 
time or location, migration), as well as effects on habitat, and the 
likely effectiveness of the mitigation. We also assess the number, 
intensity, and context of estimated takes by evaluating this 
information relative to population status. Consistent with the 1989 
preamble for NMFS's implementing regulations (54 FR 40338; September 
29, 1989), the impacts from other past and ongoing anthropogenic 
activities are incorporated into this analysis via their impacts on the 
environmental baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, our analysis applies to all species listed in 
Table 1, given that NMFS expects the anticipated effects of the planned 
geophysical survey to be similar in nature. Where there are meaningful 
differences between species or stocks, or groups of species, in 
anticipated individual responses to activities, impact of expected take 
on the population due to differences in population status, or impacts 
on habitat, NMFS has identified species-specific factors to inform the 
analysis.
    As described above, we have authorized only the takes estimated to 
occur outside of Mexican territorial waters (Table 7); however, for the 
purposes of our negligible impact analysis and determination, we 
consider the total number of takes that are anticipated to occur as a 
result of the entire survey (including the portion of the survey that 
would occur within the Mexican territorial waters (approximately 6 
percent of the survey) (Table 8).

                                           Table 8--Total Estimated Take Including Mexican Territorial Waters
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Level B         Level A
                                                            harassment      harassment        Level B         Level A
                                                            (excluding      (excluding      harassment      harassment     Total Level B   Total Level A
                         Species                              Mexican         Mexican        (Mexican        (Mexican       harassment      harassment
                                                            territorial     territorial     territorial     territorial
                                                              waters)         waters)         waters)         waters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale..........................................               8               0               1               0               9               0
Minke whale.............................................               2               0               0               0               2               0
Bryde's whale...........................................              27               1               2               0              29               1
Fin whale...............................................               2               0               0               0               2               0
Sei whale...............................................               3               0               0               0               3               0
Blue whale..............................................               5               0               0               0               5               0
Sperm whale.............................................              12               0               1               0              13               0
Cuvier's beaked whale...................................              69               0              69               0             138               0
Longman's beaked whale..................................               3               0               0               0               3               0
Mesoplodon spp..........................................              23               0               1               0              24               0
Risso's dolphin.........................................             328               0              22               0             350               0
Rough-toothed dolphin...................................             597               0              38               0             635               0
Common bottlenose dolphin...............................           2,274               0             196               0           2,470               0
Pantropical spotted dolphin.............................           7,988               0             519               0           8,507               0
Spinner dolphin (whitebelly)............................             121               0               7               0             128               0
Spinner dolphin (eastern)...............................           8,189               0             557               0           8,746               0
Striped dolphin.........................................           2,212               0             122               0           2,334               0
Short-beaked common dolphin.............................           2,818               0             209               0           3,027               0
Fraser's dolphin........................................             858               0              58               0             916               0
Short-finned pilot whale................................             244               0              15               0             259               0
Killer whale............................................              25               0               2               0              27               0
False killer whale......................................             118               0               8               0             126               0
Pygmy killer whale......................................             116               0               8               0             124               0
Melon-headed whale......................................             135               0               9               0             144               0
Kogia spp...............................................              33               1               2               0              35               1
Guadalupe fur seal......................................             416               0               1               0             417               0
California sea lion.....................................             365               0             693               0           1,058               0
--------------------------------------------------------------------------------------------------------------------------------------------------------

    NMFS does not anticipate that takes by serious injury or mortality 
would occur as a result of L-DEO's planned survey, even in the absence 
of mitigation, and no such takes are authorized. Non-auditory physical 
effects, stranding, and vessel strike are also not expected to occur.
    We have authorized a limited number of instances of Level A 
harassment of two species (Bryde's whale and dwarf sperm whales, which 
are members of the low- and high-frequency cetacean hearing groups, 
respectively) in the form of PTS, and Level B harassment only of the 
remaining marine mammal species. We believe that any PTS incurred in 
marine mammals as a result of the planned activity would be in the form 
of only a small degree of PTS, not total deafness, because of the 
constant movement of both the R/V Langseth and of the marine mammals in 
the project areas, as well as the fact that the vessel is not expected 
to remain in any one area in which individual marine mammals would be 
expected to concentrate for an extended period of time. Additionally, 
L-DEO must shut down the airgun array if marine mammals approach within 
500 m (with the exception of specific genera of dolphins, see 
Mitigation), further reducing the expected duration and intensity of 
sound, and therefore the likelihood of marine mammals incurring PTS. 
Since the duration of exposure to loud sounds will be relatively short, 
it would be unlikely to affect the fitness of any individuals. Also, as 
described above, we expect that marine mammals would likely move away 
from a sound source that represents an aversive stimulus, especially at 
levels that would be expected to result in PTS, given sufficient notice 
of the R/V Langseth's approach due to the vessel's relatively low speed 
when conducting seismic surveys. Accordingly, we expect that the 
majority of takes would be in the form of short-term Level B behavioral 
harassment in the form of temporary avoidance of the area or decreased 
foraging (if such activity were

[[Page 27130]]

occurring), reactions that are considered to be of low severity and 
with no lasting biological consequences (e.g., Southall et al., 2007, 
Ellison et al., 2012). L-DEO will only survey ``nearshore'' tracklines 
between May 1 and October 31, at which point no breeding humpback 
whales are expected to be in survey area. We therefore expect no 
impacts on the fitness of individual humpback whales or on recruitment 
of survival for the population as a whole.
    Marine mammal habitat may be impacted by elevated sound levels, but 
these impacts would be temporary. Prey species are mobile and are 
broadly distributed throughout the project areas; therefore, marine 
mammals that may be temporarily displaced during survey activities are 
expected to be able to resume foraging once they have moved away from 
areas with disturbing levels of underwater noise. Because of the 
relatively short duration (up to 25 days) and temporary nature of the 
disturbance, the availability of similar habitat and resources in the 
surrounding area, the impacts to marine mammals and the food sources 
that they utilize are not expected to cause significant or long-term 
consequences for individual marine mammals or their populations.
    Yazvenko et al. (2007) reported no apparent changes in the 
frequency of feeding activity in Western gray whales exposed to airgun 
sounds in their feeding grounds near Sakhalin Island. Goldbogen et al. 
(2013) found blue whales feeding on highly concentrated prey in shallow 
depths were less likely to respond and cease foraging than whales 
feeding on deep, dispersed prey when exposed to simulated sonar 
sources, suggesting that the benefits of feeding for humpbacks foraging 
on high-density prey may outweigh perceived harm from the acoustic 
stimulus, such as the seismic survey (Southall et al., 2016). 
Additionally, L-DEO must shut down the airgun array upon observation of 
an aggregation of six or more large whales, which would reduce impacts 
to cooperatively foraging animals. For all habitats, no physical 
impacts to habitat are anticipated from seismic activities. While SPLs 
of sufficient strength have been known to cause injury to fish and fish 
and invertebrate mortality, in feeding habitats, the most likely impact 
to prey species from survey activities would be temporary avoidance of 
the affected area and any injury or mortality of prey species would be 
localized around the survey and not of a degree that would adversely 
impact marine mammal foraging. The duration of fish avoidance of a 
given area after survey effort stops is unknown, but a rapid return to 
normal recruitment, distribution and behavior is expected. Given the 
short operational seismic time near or traversing specific habitat 
areas, as well as the ability of cetaceans and prey species to move 
away from acoustic sources, NMFS expects that there would be, at worst, 
minimal impacts to animals and habitat within these areas. The planned 
survey tracklines do not overlap with any designated critical habitat 
for ESA-listed species or areas of known importance for any species.

Negligible Impact Conclusions

    The planned survey is of short duration (up to 25 days of seismic 
operations), and the acoustic ``footprint'' of the survey is small 
relative to the ranges of the marine mammals that would potentially be 
affected. Sound levels would increase in the marine environment in a 
relatively small area surrounding the vessel compared to the range of 
the marine mammals within the survey area. Short-term exposures to 
survey operations are not likely to significantly disrupt marine mammal 
behavior, and the potential for longer-term avoidance of important 
areas is limited.
    The required mitigation measures are expected to reduce the number 
of takes by Level A harassment (in the form of PTS) by allowing for 
detection of marine mammals in the vicinity of the vessel by visual and 
acoustic observers. The required mitigation measures are also expected 
to minimize the severity of any potential behavioral disturbance (Level 
B harassment) via shutdowns of the airgun array. Based on previous 
monitoring reports for substantially similar activities that have been 
previously authorized by NMFS (available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities), we expect that the 
mitigation will be effective in preventing, at least to some extent, 
potential PTS in marine mammals that may otherwise occur in the absence 
of the required mitigation (although all authorized PTS has been 
accounted for in this analysis).
    NMFS concludes that exposures to marine mammal species and stocks 
due to L-DEO's seismic survey activities would result in only short-
term (temporary and short in duration) effects to individuals exposed, 
over relatively small areas of the affected animals' ranges. Animals 
may temporarily avoid the immediate area, but are not expected to 
permanently abandon the area. Major shifts in habitat use, 
distribution, or foraging success are not expected. Due to the timing 
of the survey, no impacts to breeding humpback whales are anticipated 
and NMFS does not anticipate the authorized take to impact annual rates 
of recruitment or survival for humpback whales or any other species.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized, even absent mitigation;
     The planned activity is temporary and of relatively short 
duration (up to 25 days);
     The anticipated impacts of the activity on marine mammals 
would primarily be temporary behavioral changes due to avoidance of the 
area around the survey vessel;
     The number of instances of potential PTS that may occur 
are expected to be very small in number. Instances of potential PTS 
that are incurred in marine mammals are expected to be of a low level, 
due to constant movement of the vessel and of the marine mammals in the 
area, and the nature of the survey design (not concentrated in areas of 
high marine mammal concentration);
     The availability of alternate areas of similar habitat 
value for marine mammals to temporarily vacate the survey area during 
the survey to avoid exposure to sounds from the activity;
     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 required mitigation measures, including visual and 
acoustic monitoring and shutdowns are expected to minimize potential 
impacts to marine mammals (both amount and severity).
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the required mitigation and 
monitoring measures, NMFS finds that the total marine mammal take from 
the planned activity will have a negligible impact on all affected 
marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other

[[Page 27131]]

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 authorized take is below one third of the estimated 
population abundance of all species (Gerrodette and Palacios 1996; NMFS 
2015b). In fact, take of individuals is less than 8 percent of the 
abundance of any affected population.
    Based on the analysis contained herein of the planned activity 
(including the required mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    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 would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

National Environmental Policy Act

    In compliance with Executive Order (E.O.) 12114, the NSF prepared 
an Environmental Analysis to consider the direct, indirect and 
cumulative effects to the human environment resulting from this marine 
geophysical survey in the Eastern Tropical Pacific. The NSF's 
Environmental Analysis tiers to the 2011 Final Programmatic 
Environmental Impact Statement/Overseas Environmental Impact Statement 
for marine-related research funded by the NSF, which was prepared under 
E.O. 12114 and the National Environmental Policy Act (NEPA).
    NMFS determined that the form and substance of the Environmental 
Analysis satisfies all the requirements of an Environmental Assessment 
under NEPA, as implemented by the regulations published by the Council 
on Environmental Quality (CEQ; 40 CFR parts 1500-1508) and includes 
adequate information analyzing the effects on the human environment of 
issuing the IHA. The NSF's draft Environmental Analysis was made 
available to the public for review and comment. In compliance with NEPA 
and CEQ regulations, as well as NOAA Administrative Order 216-6A, NMFS 
has reviewed the NSF's Environmental Analysis, determined it to be 
sufficient, and adopted that Environmental Analysis. The NSF's 
Environmental Analysis and NMFS' Determination are available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities.

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.
    The NMFS OPR ESA Interagency Cooperation Division issued a 
Biological Opinion under section 7 of the ESA, on the issuance of an 
IHA to L-DEO under section 101(a)(5)(D) of the MMPA by the NMFS OPR 
Permits and Conservation Division and the NSF's funding of L-DEO's 
survey. 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, Mexico DPS humpback whales, Central 
America DPS humpback whales, and Guadalupe fur seals.

Authorization

    As a result of these determinations, NMFS has issued an IHA to L-
DEO for conducting geophysical surveys of the Guerrero Gap in the 
Eastern Tropical Pacific in spring 2022, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated.

    Dated: May 2, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2022-09792 Filed 5-5-22; 8:45 am]
BILLING CODE 3510-22-P