Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 27111 

Respondent’s Obligation: Required to 

Obtain or Retain Benefits. 

Legal Authority: Magnuson-Stevens 

Fishery Conservation and Management 

Act (16 U.S.C. 1801 et seq.; 50 CFR 

665.819). 

This information collection request 

may be viewed at reginfo.gov. Follow 

the instructions to view Department of 

Commerce collections currently under 

review by OMB. 

Written comments and 

recommendations for the proposed 

information collection should be 

submitted within 30 days of the 

publication of this notice on the 

following website www.reginfo.gov/ 

public/do/PRAMain. Find this 

particular information collection by 

selecting ‘‘Currently under 30-day 

Review—Open for Public Comments’’ or 

by using the search function and 

entering either the title of the collection 

or the OMB Control Number 0648–0689. 

Sheleen Dumas, 

Department PRA Clearance Officer, Office of 

the Chief Information Officer, Commerce 

Department. 

[FR Doc. 2022–09830 Filed 5–5–22; 8:45 am] 

BILLING CODE 3510–22–P 

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). 

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-undermarine-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 highenergy 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 (in3) 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 


JSPEARS on DSK121TN23PROD with NOTICES1
27112 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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 

Mastozoologı ́a Marina, A.C. 

(SOMEMMA). The Sociedad Mexicana 

de Mastozoologı ́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 regionwide 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 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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 


JSPEARS on DSK121TN23PROD with NOTICES1
27114 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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/marinemammal-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/draftmarine-mammal-stock-assessmentreports). 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 extincio ́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 proteccio ́n especial’’ 

(subject to special protection). 

TABLE 1—MARINE MAMMALS THAT COULD OCCUR IN THE SURVEY AREA

Common name Scientific name Stock 

ESA/ 

MMPA 

status; 

strategic 

(Y/N) 1

Stock abundance (CV, 

Nmin, most recent 

abundance survey) 2

PBR Annual 

M/SI 3

ETP 

abundance 4

Mexico 

Pacific 

abundance 5

Order Cetartiodactyla—Cetacea—Superfamily Mysticeti (baleen whales) 

Family 

Balaenopteridae 

(rorquals): 

Humpback Whale Megaptera 

novaeangliae.

Central N Pacific -, -, Y 10,103 (0.3, 7,890, 

2006).

83 ................... 26 2,566 ....................

Minke whale ......... Balaenoptera 

acutorostrata.

N/A ...................... -, -, N N/A ............................. N/A ................. N/A 115 ....................

Bryde’s whale ...... Balaenoptera edeni .... Eastern Tropical 

Pacific.

-, -, N Unknown (Unknown, 

Unknown, N/A).

Undetermined Unknown 10,411 649 

Sei whale ............. Balaenoptera borealis Eastern N Pacific E, D, Y 519 (0.4, 374, 2014) .. 0.75 ................ ≥0.2 0 ....................


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 27115 

TABLE 1—MARINE MAMMALS THAT COULD OCCUR IN THE SURVEY AREA—Continued 

Common name Scientific name Stock 

ESA/ 

MMPA 

status; 

strategic 

(Y/N) 1

Stock abundance (CV, 

Nmin, most recent 

abundance survey) 2

PBR Annual 

M/SI 3

ETP 

abundance 4

Mexico 

Pacific 

abundance 5

Fin whale ............. Balaenoptera 

physalus.

N/A ...................... E, D, Y N/A ............................. N/A ................. N/A 574 145 

Blue whale ........... Balaenoptera 

musculus.

Eastern N Pacific E, D, Y 1,898 (0.085, 1,767, 

2018).

4.1 .................. ≥19.4 1,415 773 

Superfamily Odontoceti (toothed whales, dolphins, and porpoises) 

Family Physeteridae: 

Sperm whale ........ Physeter 

macrocephalus.

N/A ...................... E, D, Y N/A ............................. N/A ................. N/A 4,145 2,810 

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 cavirostris ...... N/A ...................... -, -, N N/A ............................. N/A ................. N/A 7 20,000 8 68,828 

Longman’s beaked 

whale.

Indopacetus pacificus N/A ...................... -, -, N N/A ............................. N/A ................. N/A 1,007 ....................

Blainville’s beaked 

whale.

Mesoplodon 

densirostris.

N/A ...................... -, -, N N/A ............................. N/A ................. N/A 9 25,300 8 68,828 

Ginkgo-toothed 

beaked whale.

M. ginkgodens ........... N/A ...................... -, -, N N/A ............................. N/A ................. N/A 9 25,300 8 68,828 

Deraniyagala’s 

beaked whale.

M. hotaula .................. N/A ...................... -, -, N N/A ............................. N/A ................. N/A 9 25,300 8 68,828 

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 bredanensis ..... N/A ...................... -, -, N N/A ............................. N/A ................. N/A 107,663 37,511 

Common 

bottlenose dolphin.

Tursiops truncatus ..... N/A ...................... -, -, N N/A ............................. N/A ................. N/A 335,834 61,536 

Pantropical spotted dolphin.Stenella attenuata ...... N/A10 .................. -, D, N N/A ............................. N/A ................. N/A 11 1,297,091 146,296 

Spinner dolphin .... Stenella longirostris ... N/A10 .................. -, D, N N/A ............................. N/A ................. N/A 11 2,075,871 186,906 

Striped dolphin ..... Stenella coeruleoalba N/A ...................... -, -, N N/A ............................. N/A ................. N/A 964,362 128,867 

Short-beaked 

common dolphin.

Delphinus delphis ...... N/A ...................... -, -, N N/A ............................. N/A ................. N/A 3,127,203 283,196 

Fraser’s dolphin ... Lagenodelphis hosei .. N/A ...................... -, -, N N/A ............................. N/A ................. N/A 7 289,300 ....................

Short-finned pilot 

whale.

Globicephala 

macrorhynchus.

N/A ...................... -, -, N N/A ............................. N/A ................. N/A 12 589,315 3,348 

Killer whale .......... Orcinus orca .............. N/A ...................... -, -, N N/A ............................. N/A ................. N/A 7 8,500 852 

False killer whale Pseudorca crassidens N/A ...................... -, -, N N/A ............................. N/A ................. N/A 7 39,800 ....................

Pygmy killer whale Feresa attenuata ........ N/A ...................... -, -, N N/A ............................. N/A ................. N/A 7 38,900 ....................

Melon-headed 

whale.

Peponocephala 

electra.

N/A ...................... -, -, N N/A ............................. N/A ................. N/A 7 45,400 ....................

Order Carnivora—Superfamily Pinnipedia 

Family Otariidae 

(eared seals and sea 

lions): 

Guadalupe fur 

seal.

Arctocephalus 

townsendi.

Mexico ................ T, D, Y 34,187 (N/A, 31,019, 

2013).

1,062 .............. ≥3.8 .................... ....................

California sea lion Zalophus californianus U.S ...................... -, -, N 257,606 (N/A,233,515, 

2014).

14,011 ............ >320 105,000 ....................

1Endangered 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. 3These 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. 4From NMFS (2015b) unless otherwise noted. 

5Pacific Mexico excluding the Gulf of California (from Gerrodette and Palacios (1996) unless otherwise noted). 

6Estimate for ETP is mostly for K. sima but may also include some K. breviceps (Wade and Gerrodette 1993). 7Wade and Gerrodette 1993. 

8Abundance for all ziphiids. 

9This estimate for the ETP includes all species of the genus Mesoplodon. 10Several 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. 


JSPEARS on DSK121TN23PROD with NOTICES1
27116 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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/incidentaltake-authorizations-research-and-otheractivities. 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 lowfrequency 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 whales) ......................................................................................................................... 7 Hz to 35 kHz. 

Mid-frequency (MF) cetaceans (dolphins, toothed whales, beaked whales, bottlenose whales) .............................................. 150 Hz to 160 kHz. 

High-frequency (HF) cetaceans (true porpoises, Kogia, river dolphins, cephalorhynchid, Lagenorhynchus cruciger & L. 

australis).

275 Hz to 160 kHz. 

Phocid pinnipeds (PW) (underwater) (true seals) ....................................................................................................................... 50 Hz to 86 kHz. 

Otariid pinnipeds (OW) (underwater) (sea lions and fur seals) .................................................................................................. 60 Hz to 39 kHz. 

* 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 

(Hemila ̈ 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 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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 (mPa) root mean square 

(rms) for continuous (e.g., vibratory piledriving, drilling) and above 160 dB re 1 

mPa (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 mPa (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 nonimpulsive). 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-technicalguidance. 

TABLE 3—THRESHOLDS IDENTIFYING THE ONSET OF PERMANENT THRESHOLD SHIFT

Hearing group 

PTS onset acoustic thresholds * 

(received level) 

Impulsive Non-impulsive 

Low-Frequency (LF) Cetaceans ...................................... Cell 1: Lpk,flat: 219 dB; LE,LF,24h: 183 dB ......................... Cell 2: LE,LF,24h: 199 dB. 

Mid-Frequency (MF) Cetaceans ...................................... Cell 3: Lpk,flat: 230 dB; LE,MF,24h: 185 dB ........................ Cell 4: LE,MF,24h: 198 dB. 

High-Frequency (HF) Cetaceans ..................................... Cell 5: Lpk,flat: 202 dB; LE,HF,24h: 155 dB ........................ Cell 6: LE,HF,24h: 173 dB. 

Phocid Pinnipeds (PW) ....................................................

(Underwater) ....................................................................

Cell 7: Lpk,flat: 218 dB; LE,PW,24h: 185 dB ....................... Cell 8: LE,PW,24h: 201 dB. 

Otariid Pinnipeds (OW) ....................................................

(Underwater) ....................................................................

Cell 9: Lpk,flat: 232 dB; LE,OW,24h: 203 dB ....................... Cell 10: LE,OW,24h: 219 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. 


JSPEARS on DSK121TN23PROD with NOTICES1
27118 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

Note: Peak sound pressure (Lpk) has a reference value of 1 μPa, and cumulative sound exposure level (LE) has a reference value of 1μPa2s. 

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 in3 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 constantvelocity 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 seafloorreflected 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

Source and volume Tow depth 

(m) 

Water depth 

(m) 

Level B 

harassment 

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 × 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 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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 farfield signature is not necessarily the best 

measurement of the source level that is 

physically achieved at the source 

(Tolstoy et al., 2009). Near the source (at 

short ranges, distances <1 km), the 

pulses of sound pressure from each 

individual airgun in the source array do 

not stack constructively, as they do for 

the theoretical 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 (mPa) 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

Source 

(volume) Threshold 

Level A harassment zone 

(m) 

LF cetaceans MF cetaceans HF cetaceans Otariids 

36-airgun array (6,600 in3) ............... 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 midfrequency 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 


JSPEARS on DSK121TN23PROD with NOTICES1
27120 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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 nearfield 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: 

with the condition that D >> l, and 

where D is the distance, L is the longest 

dimension of the array, and l is the 

wavelength of the signal (Lurton, 2002). 

Given that l can be defined by: 

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: 

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/farfield 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 nearfield 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- 

in3 airgun array planned for use during 

the planned survey has an approximate 

diagonal of 28.8 m, resulting in a nearfield 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 nearfield 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 habitatbased 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 


JSPEARS on DSK121TN23PROD with NOTICES1EN06MY22.025</GPH> EN06MY22.026</GPH> EN06MY22.027</GPH>
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 27121 

fisheries research activities (NMFS 

2015b). These estimates were derived 

from abundance estimates using shipbased surveys of marine mammals in 

the ETP, as reported by Gerrodette et al. 

(2008). While the SWFSC developed 

volumetric density estimates (animals/ 

km3) to account for typical dive depth 

of each species (0–200 m and >200 m), 

L–DEO used the area density (animals/ 

km2) 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

Species 

Density (#/km2) in survey area 

Shallow water 

(<100 m) 

Intermediate water 

(100–1,000 m) 

Deep water 

(>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. 


JSPEARS on DSK121TN23PROD with NOTICES1
27122 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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

Species 

Estimated 

takes by Level 

B harassment 

Estimated 

takes by Level 

A harassment 

Authorized 

takes by Level 

B harassment 

Authorized 

takes by Level 

A harassment 

Total 

authorized 

take 

Regional 

population 

size 

Percent of 

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 

aEstimated population in Pacific waters of Mexico (Gerrodette and Palacios (1996)). 

bAuthorized take increased to maximum group size. 

cPopulation in ETP or wider Pacific (NMFS 2015b). 

dPopulation 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, 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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° 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 


JSPEARS on DSK121TN23PROD with NOTICES1
27124 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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 PreStart 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 stepwise 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 rampup (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 prestart 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 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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 rampup 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 rampup. 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 midfrequency 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 twothirds 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 


JSPEARS on DSK121TN23PROD with NOTICES1
27126 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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 pedestalmounted 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 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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 thirdparty 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. 


JSPEARS on DSK121TN23PROD with NOTICES1
27128 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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 restranding, 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., populationlevel 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, 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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

Species 

Level B 

harassment 

(excluding 

Mexican territorial waters) 

Level A 

harassment 

(excluding 

Mexican territorial waters) 

Level B 

harassment 

(Mexican territorial waters) 

Level A 

harassment 

(Mexican territorial waters) 

Total Level B 

harassment 

Total Level A 

harassment 

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 


JSPEARS on DSK121TN23PROD with NOTICES1
27130 Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 

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 highdensity 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 longerterm 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/incidentaltake-authorizations-research-and-otheractivities), 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 


JSPEARS on DSK121TN23PROD with NOTICES1
Federal Register / Vol. 87, No. 88 / Friday, May 6, 2022 / Notices 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/incidentaltake-authorizations-research-and-otheractivities. 

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 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

Agency Information Collection 

Activities; Submission to the Office of 

Management and Budget (OMB) for 

Review and Approval; Comment 

Request; Southeast Region Vessel 

Monitoring System (VMS) and Related 

Requirements 

The Department of Commerce will 

submit the following information 

collection request to the Office of 

Management and Budget (OMB) for 

review and clearance in accordance 

with the Paperwork Reduction Act of 

1995, on or after the date of publication 

of this notice. We invite the general 

public and other Federal agencies to 

comment on proposed, and continuing 

information collections, which helps us 

assess the impact of our information 

collection requirements and minimize 

the public’s reporting burden. Public 

comments were previously requested 

via the Federal Register on January 12, 

2022, during a 60-day comment period. 

This notice allows for an additional 30 

days for public comments. 

Agency: National Oceanic & 

Atmospheric Administration (NOAA), 

Commerce. 

Title: Southeast Region Vessel 

Monitoring System and Related 

Requirements. 

OMB Control Number: 0648–0544. 

Form Number(s): None. 

Type of Request: Regular submission 

(extension of a current information 

collection). 

Number of Respondents: 901. 

Average Hours per Response: Annual 

VMS maintenance, 2 hours; Installation/ 

Activation of VMS unit, 5 hours; 

Installation and activation checklist, 20 

minutes; power-down exemption 

request, 5 minutes; and trip declaration, 

1 minute. 

Total Annual Burden Hours: 2,628. 

Needs and Uses: The NMFS, Office of 

Law Enforcement, Southeast 

Enforcement Division is submitting this 

request for an extension of a currently 

approved information collection. 

The Magnuson-Stevens Fishery 

Conservation and Management Act 

authorizes the Gulf of Mexico Fishery 

Management Council (Gulf Council) and 

South Atlantic Fishery Management 

Council (South Atlantic Council) to 

prepare and amend fishery management 

plans for any fishery in Federal waters 

under their respective jurisdictions. 

NMFS and the Gulf Council manage the 

reef fish fishery in the Gulf of Mexico 

(Gulf) under the Fishery Management 


JSPEARS on DSK121TN23PROD with NOTICES1