Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28787 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

[RTID 0648–XB015] 

Takes of Marine Mammals Incidental to 

Specified Activities; Taking Marine 

Mammals Incidental to a Geophysical 

Survey in the Arctic Ocean 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Notice; proposed incidental 

harassment authorization; request for 

comments on proposed authorization 

and possible renewal. 

SUMMARY: NMFS has received a request 

from the University of Alaska 

Geophysics Institute (UAGI) for 

authorization to take marine mammals 

incidental to a geophysical survey in the 

Arctic Ocean. The proposed survey 

would be funded by the National 

Science Foundation (NSF). Pursuant to 

the Marine Mammal Protection Act 

(MMPA), NMFS is requesting comments 

on its proposal to issue an incidental 

harassment authorization (IHA) to 

incidentally take marine mammals 

during the specified activities. NMFS is 

also requesting comments on a possible 

one-time, one-year renewal that could 

be issued under certain circumstances 

and if all requirements are met, as 

described in Request for Public 

Comments at the end of this notice. 

NMFS will consider public comments 

prior to making any final decision on 

the issuance of the requested MMPA 

authorizations and agency responses 

will be summarized in the final notice 

of our decision. 

DATES: Comments and information must 

be received no later than June 28, 2021. 

ADDRESSES: Comments should be 

addressed to Jolie Harrison, Chief, 

Permits and Conservation Division, 

Office of Protected Resources, National 

Marine Fisheries Service and should be 

submitted via email to ITP.Corcoran@

noaa.gov. 

Instructions: NMFS is not responsible 

for comments sent by any other method, 

to any other address or individual, or 

received after the end of the comment 

period. Comments, including all 

attachments, must not exceed a 25- 

megabyte file size. All comments 

received are a part of the public record 

and will generally be posted online at 

www.fisheries.noaa.gov/permit/ 

incidental-take-authorizations-undermarine-mammal-protection-act without 

change. All personal identifying 

information (e.g., name, address) 

voluntarily submitted by the commenter 

may be publicly accessible. Do not 

submit confidential business 

information or otherwise sensitive or 

protected information. 

FOR FURTHER INFORMATION CONTACT: Kim 

Corcoran, Office of Protected Resources, 

NMFS, (301) 427–8401. Electronic 

copies of the application and supporting 

documents, as well as a list of the 

references cited in this document, may 

be obtained online at: https://

www.fisheries.noaa.gov/permit/ 

incidental-take-authorizations-undermarine-mammal-protection-act. In case 

of problems accessing these documents, 

or for anyone who is unable to comment 

via electronic mail, please call the 

contact listed above. 

SUPPLEMENTARY INFORMATION: 

Background 

The MMPA prohibits the ‘‘take’’ of 

marine mammals, with certain 

exceptions. Sections 101(a)(5)(A) and 

(D) of the MMPA (16 U.S.C. 1361 et 

seq.) direct the Secretary of Commerce 

(as delegated to NMFS) to allow, upon 

request, the incidental, but not 

intentional, taking of small numbers of 

marine mammals by U.S. citizens who 

engage in a specified activity (other than 

commercial fishing) within a specified 

geographical region if certain findings 

are made and either regulations are 

issued or, if the taking is limited to 

harassment, a notice of a proposed 

incidental take authorization may be 

provided to the public for review. 

Authorization for incidental takings 

shall be granted if NMFS finds that the 

taking will have a negligible impact on 

the species or stock(s) and will not have 

an unmitigable adverse impact on the 

availability of the species or stock(s) for 

taking for subsistence uses (where 

relevant). Further, NMFS must prescribe 

the permissible methods of taking and 

other means of effecting the least 

practicable adverse impact on the 

affected species or stocks and their 

habitat, paying particular attention to 

rookeries, mating grounds, and areas of 

similar significance, and on the 

availability of the species or stocks for 

taking for certain subsistence uses 

(referred to in shorthand as 

‘‘mitigation’’); and requirements 

pertaining to the monitoring and 

reporting of the takings. 

The definitions of all applicable 

MMPA statutory terms cited above are 

included in the relevant sections below. 

National Environmental Policy Act 

To comply with the National 

Environmental Policy Act of 1969 

(NEPA; 42 U.S.C. 4321 et seq.) and 

NOAA Administrative Order (NAO) 

216–6A, NMFS must review our 

proposed action (i.e., the issuance of an 

IHA) with respect to potential impacts 

on the human environment. 

NMFS plans to adopt the NSF’s 

Environmental Assessment (EA), as we 

have preliminarily determined that it 

includes adequate information 

analyzing the effects on the human 

environment of issuing the IHA. NSF’s 

EA is available at www.nsf.gov/geo/oce/ 

envcomp/. 

We will review all comments 

submitted in response to this notice 

prior to concluding our NEPA process 

or making a final decision on the IHA 

request. 

Summary of Request 

On February 12, 2021, NMFS received 

a request from UAGI for an IHA to take 

marine mammals incidental to a 

geophysical survey in the Arctic Ocean. 

The application was deemed adequate 

and complete on April 6, 2021. UAGI’s 

request is for take of 13 species of 

marine mammals, by Level B 

harassment only. No Level A 

harassment is anticipated. Neither UAGI 

nor NMFS expects serious injury or 

mortality to result from this activity. 

Therefore, an IHA is appropriate. 

Description of Proposed Activity 

Overview 

Researchers at UAGI, with funding 

from NSF, propose to conduct a seismic 

survey from the Research Vessel (R/V) 

Sikuliaq in the Arctic Ocean to 

document the structure and stratigraphy 

of the Chukchi Borderland and adjacent 

Canada basin. The proposed activity is 

planned to take place in late summer 

2021 (August/September) with a total of 

30 days of data acquisition. The survey 

would include both high energy and 

low energy components. High-energy 

ocean bottom seismometer (OBS) 

refraction surveys will use a 6-airgun, 

3120 cubic inches (in3) array and 

consist of ∼12 percent of total survey 

effort (henceforth referred to as highenergy survey). Low-energy multichannel seismic (MCS) reflection 

surveys will use a 2-airgun array with a 

total discharge volume of 1040 in3 and 

consist of ∼88 percent of total survey 

effort (henceforth referred to as lowenergy survey). 

Dates and Duration 

The proposed activity will occur 

between August and September, 2021. 

The activity is planned to occur for 45 

days total, with ∼30 days dedicated to 

seismic data acquisition (with 24-hours 

28788 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

a day operations), ∼8 days devoted to 

transit and 7 days used for equipment 

deployment and recovery. 

Specific Geographic Region 

The proposed surveys would occur 

within ∼73.5–81.0°N, ∼139.5–168°W 

(≥300 kilometer (km) north of 

Utqiag ̇vik). Representative survey track 

lines can be seen in Figure 1. Some 

deviation in track lines, including the 

order of survey operations, could be 

necessary for reasons such as science 

drivers, poor data quality, inclement 

weather, or mechanical issues with the 

research vessel and/or equipment. Thus, 

the track lines could occur anywhere 

within the coordinates noted above and 

within the study area. Four percent of 

the surveys will occur within the U.S. 

Exclusive Economic Zone (EEZ) with 

the remaining part of the survey 

occurring beyond the EEZ. The activity 

will take place in depths ranging from 

200–4,000 meters (m). The R/V Sikuliaq 

would likely leave and return to Nome, 

AK. 

The low-energy survey activity will 

begin ∼300 km from the Alaskan 

coastline (North of Utqiagvik) and 

extend ∼800 km north from the initial 

survey site (i.e., the survey would occur 

∼300–1,100 km from the Alaska 

coastline). The high-energy survey 

activity will only occur ∼530 km from 

the coastline and occur only in the 

northeastern part of the survey area (See 

Figure 1). Eighty percent of the total 

survey will occur in deep waters 

(>1,000m) with the remainder of the 

survey occurring in intermediate depth 

waters (100–1,000 m); no surveying will 

occur in waters <100 m deep. All highenergy surveys (680 km total) will occur 

in deep waters, while 67 percent of lowenergy surveys will occur in deep 

waters (3,981 km) with the remainder 

occurring in intermediate depth waters 

(1,189 km or 23 percent). 

BILLING CODE 3510–22–P 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28789 

BILLING CODE 3510–22–C 

Detailed Description of Specific Activity 

The proposed study would use lowenergy two-dimensional (2–D) seismic 

surveying to document the history, 

structure, and stratigraphy of the 

Chukchi Borderland and adjacent 

Canada Basin, and use high-energy 

seismic refraction data in the Canada 

Basin to characterize the deep crustal 

structure associated with an extinct 

mid-ocean ridge in the central basin. 

The procedures to be used for the 

proposed marine geophysical survey 

would include conventional seismic 

methodology. The survey would involve 

one source vessel, R/V Sikuliaq, which 

has a cruising speed of 10 knots (kt), 

and would tow an array of 6 airguns 

(520 in3 (8,521.27 cm3) each) and a total 

possible discharge volume of ∼3,120 in3

during high-energy surveys. During lowenergy reflection surveys, a 2-airgun 

array (at 520 in3 each) would be used 

with a total discharge volume of 1,040 

in3. Both arrays will be towed at a depth 

of 9m. During low-energy surveys (∼88 

percent of total line km), a 1–3 km long 

hydrophone streamer (depending on ice 

conditions) would be employed as the 

receiving system, and high-energy 

surveys (∼12 percent of total line km) 

would employ nine OBSs as the 

receiving system. As the airgun arrays 


EN28MY21.002</GPH>

Figure 1. Location of the proposed seismic surveys and OBS deployments in the 

Arctic Ocean and Endangered Species Act critical habitat in the U.S. 
28790 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

are towed along the survey lines, the 

OBSs would receive and store the 

returning acoustic signals internally for 

later analysis, and the hydrophone 

streamer would transfer the data to the 

on-board processing system. The 

airguns would fire at a shot interval of 

35 m (∼15 seconds (s)) during the lowenergy surveys and at a 139-m (∼60 s) 

interval during the high-energy 

refraction surveys. The airguns would 

operate at a firing pressure of 2,540 

pounds per square inch (psi). 

In addition to the aforementioned 

planned survey lines, some lines, as 

indicated in Figure 1, will be surveyed 

twice: Once for low-energy reflection 

and again for high energy refraction. 

These surveys would take place near the 

end of operations in the northeastern 

part of the survey area (Fig. 1); however, 

the location of these surveys could shift 

slightly to ensure one survey occurs 

over the extinct ridge axis and the other 

on hyper-extended continental crust. A 

total of nine OBSs would be deployed 

twice for a total of 18 deployment sites 

during high energy survey effort. Nine 

OBSs would be deployed during lowenergy surveying, then high-energy 

refraction data would be acquired along 

these same lines, followed by retrieval 

of the OBS equipment, before R/V 

Sikuliaq would travel to the next site to 

deploy all nine OBSs again. 

Approximately 5,850 total line km 

would be surveyed, including 5,170 km 

of low-energy surveys, and 680 km of 

high-energy surveys. There could be 

additional seismic operations associated 

with turns, airgun testing, and repeat 

coverage of any areas where initial data 

quality is sub-standard. As a result, a 25 

percent buffer has been added in the 

form of operational days, which is 

equivalent to adding 25 percent to the 

proposed line km to be surveyed. Most 

of the survey (80 percent) would occur 

in deep water (>1,000 m), and 20 

percent would occur in intermediate 

water (100–1,000 m deep); there would 

be no effort in shallow water <100 m 

deep. 

In addition to the operations of the 

airgun array, a multibeam echosounder 

(MBES), a sub-bottom profiler (SBP), 

and an Acoustic Doppler Current 

Profiler (ADCP) would be operated from 

R/V Sikuliaq continuously during the 

seismic surveys, but not during transit 

to and from the survey area. Take of 

marine mammals is not expected to 

occur incidental to use of the MBES, 

SBP, or ADCP because they will be 

operated only during seismic 

acquisition, and it is assumed that, 

during simultaneous operations of the 

airgun array and the other sources, any 

marine mammals close enough to be 

affected by the MBES, SBP, and ADCP 

would already be affected by the 

airguns. However, whether or not the 

airguns are operating simultaneously 

with the other sources, given their 

characteristics (e.g., narrow downwarddirected beam), marine mammals would 

experience no more than one or two 

brief ping exposures, if any exposure 

were to occur. 

Proposed mitigation, monitoring, and 

reporting measures are described in 

detail later in this document (please see 

Proposed Mitigation and Proposed 

Monitoring and Reporting). 

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). Additional 

information may be found in the Aerial 

Survey of Arctic Marine Mammals 

(ASAMM) reports, which are available 

online at https://www.fisheries.noaa.

gov/alaska/marine-mammal-protection/ 

aerial-surveys-arctic-marine-mammals. 

Table 1 lists all species or stocks for 

which take is expected and proposed to 

be 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 (2020). 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 

most species, stock abundance estimates 

are based on sightings within the U.S. 

EEZ, however for some species, this 

geographic area may extend beyond U.S. 

waters. Other species may use survey 

abundance estimates. Survey abundance 

(as compared to stock or species 

abundance) is the total number of 

individuals estimated within the survey 

area, which may or may not align 

completely with a stock’s geographic 

range as defined in the SARs. These 

surveys may also extend beyond U.S. 

waters. In this case, the proposed survey 

area outside of the U.S. EEZ does not 

necessarily overlap with the ranges for 

stocks managed by NMFS. However, we 

assume that individuals of these species 

that may be encountered during the 

survey would be part of those stocks. 

Additionally, six species listed in Table 

1 indicate Unknown abundance 

estimates. This may be due to outdated 

data and population estimates or data is 

not representative of the entire stock. 

All managed stocks in this region are 

assessed in NMFS’s U.S. Alaska and 

Pacific SARs (e.g., Muto et al., 2020, 

Carretta et al., 2020). All values 

presented in Table 1 are the most recent 

available at the time of publication and 

are available in the 2019 SARs (Muto et 

al., 2020, Carretta et al., 2020) and draft 

2020 SARs (available online at: https:// 

www.fisheries.noaa.gov/national/ 

marine-mammal-protection/draftmarine-mammal-stock-assessmentreports). 

In addition, the Pacific walrus 

(Odobenus rosmarus divergens) and the 

Polar bear (Ursus maritimus) may be 

found in the Arctic. However, Pacific 

walruses and Polar bears are managed 

by the U.S. Fish and Wildlife Service 

and are not considered further in this 

document. 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28791 

TABLE 1—MARINE MAMMALS EXPECTED TO 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

Order Cetartiodactyla—Cetacea—Superfamily Mysticeti (baleen whales) 

Family Eschrichtiidae: 

Gray whale ..................... Eschrichtius robustus ........... Eastern N Pacific ................. -, -, N 26,960 (0.05, 25,849, 2016) 801 131 

Family Balaenidae: 

Bowhead whale .............. Balaena mysticetus .............. Western Arctic ...................... E, D, Y 16,820 (0.052,16,100,2011) 161 56 

Family Balaenopteridae 

(rorquals): 

Fin whale ........................ Balaenoptera physalus ......... Northeast Pacific 4 * .............. E, D, Y Unknown .............................. UND 0.6 

Humpback whale ............ Megaptera novaeangliae ...... Western N Pacific * .............. E, D, Y 1,107 (0.3, 865, 2006) ......... 3 2.8 

Minke whale ................... Balaenoptera acutorostrata .. Alaska 4 * .............................. -, -, N Unknown .............................. UND 0 

Superfamily Odontoceti (toothed whales, dolphins, and porpoises) 

Family Delphinidae: 

Beluga whale .................. Delphinapterus leucas .......... Beaufort Sea 4 ...................... -, -, N 39,258 (0.229, N/A. 1992) ... UND 102 

Eastern Chukchi ................... -, -, N 13,305 (0.51, 8,875, 2017) .. 178 55 

Killer whale ..................... Orcinus orca ......................... Alaska resident ..................... -, -, N 2,347 c (N/A, 2347, 2012) ... 24 1 

Narwhal .......................... Monodon Monoceros ........... Unidentified 4 * ...................... -, -, N Unknown .............................. UND 0 

Family Phocoenidae (porpoises): 

Harbor Porpoise ............. Phocoena phocoena ............ Bering Sea 4 * ....................... -, -, Y Unknown .............................. UND 0.4 

Order Carnivora—Superfamily Pinnipedia 

Family Phocidae (earless 

seals): 

Bearded Seal ................. Erignathus barbatus ............. Beringia 4 * ............................ T, D, Y Unknown .............................. UND 6,709 

Ribbon Seal .................... Histriophoca fasciata ............ Unidentified * ........................ -, -, N 184,687 (see SAR, 163,086, 

2013).

9,785 163 

Ringed Seal .................... Pusa hispida ......................... Arctic .................................... T, D, Y Unknown .............................. 5,100 6,459 

Spotted Seal ................... Phoca largha ........................ Bering ................................... -, -, N 461,625 (see SAR, 423,237, 

2013).

25,394 5,254 

* Stocks marked with an asterisk are addressed in further detail in the text below. 

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: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of stock 

abundance. In some cases, CV is not applicable. For most stocks of killer whales, the abundance values represent direct counts of individually identifiable animals; 

therefore there is only a single abundance estimate with no associated CV. For certain stocks of pinnipeds, abundance estimates are based upon observations of animals (often pups) ashore multiplied by some correction factor derived from knowledge of the species’ (or similar species’) life history to arrive at a best abundance estimate; therefore, there is no associated CV. In these cases, the minimum abundance may represent actual counts of all animals ashore. 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). 4Abundance estimates for these stocks are not considered current. PBR is therefore considered undetermined for these stocks, as there is no current minimum 

abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as these present the best available information for use in 

this document. 

As indicated above, all 13 species 

(with 14 managed stocks) in Table 1 

could temporally and spatially co-occur 

with the activity to the degree that take 

is reasonably likely to occur, and we 

have proposed authorizing it. All 

species that could potentially occur in 

the proposed survey areas are included 

in Table 4 of the IHA application. 

Beluga whales and ringed seals are 

the marine mammal species most likely 

to be encountered during this survey, 

with bowhead whales and bearded seals 

also having a higher likelihood of cooccuring in the survey area over the 

other proposed species in Table 1. 

However, these four species (beluga 

whales, ringed seals, bowhead whales 

and bearded seals) are most common 

within 100 km of shore, whereas the 

proposed survey would occur no closer 

than 300 km from shore, with most 

effort further north. Thus, despite their 

prevalence in Arctic waters north of 

Alaska, we expect there to be a low 

likelihood of encountering even beluga 

whales, ringed seals, bowhead whales 

and bearded seals during the proposed 

survey given the proposed activity’s 

distance from shore. 

Humpbacks, fin and minke whales 

have rarely been observed as far north 

in the Arctic Ocean as the planned 

survey location but have been spotted 

on rare occasions in areas coinciding 

with the lower latitudes of the proposed 

survey area during previous aerial 

surveys. Similar sightings during the 

proposed activity are expected to be 

limited during the proposed survey as 

the majority of the proposed survey area 

occurs in higher latitudes and outside 

typical migratory patterns for these 

species (Brueggeman, 2009; Haley et al. 

2010; Clarke et al., 2011; Schuck et al., 

2017). However, Brower et al. (2018) 

suggest that sightings of these sub-Arctic 

species are increasing in the eastern 

Chukchi Sea as of recent years due to 

climate change. Killer whales, gray 

whales, humpback whales, fin whales, 

minke whales and harbor porpoises are 

minimally sighted in the Chukchi Sea 

based on ASAMM data and are 

primarily coastal species, however 

recent monitoring activities in the 

Chukchi and Beaufort seas during 

industry seismic surveys also suggests 

that some of these species may be 

increasing in numbers in the Arctic but 

are still expected to be south of the 

proposed survey area (Funk et al., 

2010). Additionally, there are scattered 

records of narwhal in Alaskan waters, 

where the species is considered to be 

extralimital. However, we do not expect 

the species to be encountered far north 

in the proposed survey area (Reeves et 

al., 2002). Although we do not expect 


I I I I 
28792 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

the proposed survey area to coincide 

with expected ranges of the species 

described in this paragraph, takes 

equivalent to the average group size for 

the species are proposed for 

authorization at the applicant’s request 

as a precaution due to the potential that 

they could be encountered. 

Prior to 2016, humpback whales were 

listed under the ESA as an endangered 

species worldwide. Following a 2015 

global status review (Bettridge et al., 

2015), NMFS delineated 14 distinct 

population segments (DPS) with 

different listing statuses (81 FR 62259; 

September 8, 2016) pursuant to the ESA. 

The DPSs that occur in U.S. waters do 

not necessarily equate to the existing 

stocks designated under the MMPA. 

Within Alaska waters, four humpback 

whale DPSs may occur: The Western 

North Pacific (WNP) DPS (endangered), 

Hawaii DPS (not listed), Mexico DPS 

(threatened), and Central America DPS 

(endangered). According to Wade 

(2017), in the Bering, Chukchi, and 

Beaufort Seas, encountered whales are 

most likely to be from the Hawaii DPS 

(86.8 percent), but could be from the 

Mexico DPS (11.0 percent) or WNP DPS 

(2.1 percent). Note that these 

probabilities reflect the upper limit of 

the 95 percent confidence interval of the 

probability of occurrence; therefore, 

numbers may not sum to 100 percent for 

a given area. Because this project occurs 

north of the Chukchi and Beaufort Sea 

and in the Arctic, we hypothesize that 

the Western North Pacific Stock of 

humpback whales will overlap with the 

proposed survey area, and thus include 

animals from the WNP DPS, Hawaii 

DPS and Mexico DPS as previously 

mentioned. 

At this time, there is no 

comprehensive abundance estimate 

available in the SARs for the Alaska 

stock of minke whales. However, the 

International Whaling Commission 

(IWC) reports an abundance estimate of 

20,000 minke whales in the North 

Pacific (North West Pacific and Okhotsk 

Sea) (2003), which is the figure used for 

analysis. This estimate encompasses the 

distribution of minke whales throughout 

the North Pacfic extending to 80 degrees 

North. 20,000 is the most recent 

abundance estimate available for minke 

whales in the North Pacific provided by 

IWC. In 2017, the IWC Scientific 

Committee established a new group to 

review all abundance estimates and 

ensure quality and consistency across 

estimates used by IWC. According to the 

IWC website and the criteria established 

by this group, the 20,000 whale estimate 

in the North Pacific from 2003 is 

considered to be the ‘best’ estimate at 

this time. 

Similarly, although a comprehensive 

abundance estimate is not available for 

the northeast Pacific stock of fin whales, 

provisional estimates representing 

portions of the range are available. The 

same 2010 survey of the eastern Bering 

sea shelf provided an estimate of 1,061 

(CV = 0.38) fin whales (Friday et al. 

2013). The estimate is not corrected for 

missed animals, but is expected to be 

robust as previous studies have shown 

that only small correction factors are 

needed for fin whales (Barlow, 1995). 

Zerbini et al. (2006) produced an 

estimate of 1,652 (95 percent 

Confidence Interval (CI): 1,142–2,389) 

fin whales for the area described above. 

Narwhals are found year-round in the 

Arctic but rarely occur in the western 

Arctic, in areas including the Bering, 

Chukchi, and Beaufort Seas (COSEWIC, 

2004). There are three populations of 

narwhals recognized internationally 

based on geographic separation, which 

include the Baffin Bay population, 

Hudson Bay population, and the East 

Greenland population. Currently, very 

little is known about these populations. 

The primary source for data and 

knowledge of narwhals in Alaska waters 

is local observations and traditional 

ecological knowledge dating back to the 

1800s (Noogwook et al., 2007). 

Individual sightings have occurred in 

Russian waters of the northern Chukchi 

Sea (Yablokov and Bel’kovich, 1968; 

Reeves and Tracey, 1980). Additionally, 

Alaska Native hunters recorded seven 

sightings of narwhals between 1989 and 

2008, four of which consisted of mixed 

groups of narwhals and belugas (George 

and Suydam, unpublished manuscript). 

Records of narwhals in the Beaufort, 

Chukchi, and Bering Seas are 

hypothesized to be whales from the 

Baffin Bay population, migrating into 

the Canadian Arctic as ice conditions 

permit (COSEWIC, 2004). At this time, 

there are no reliable estimates of 

abundance for narwhals in Alaskan 

waters. 

Based on previous industry-sponsored 

monitoring in the Beaufort Sea, harbor 

porpoises regularly occur in both the 

Chukchi and Beaufort Seas (Funk et al., 

2011). They have been sighted during 

several seismic surveys, both nearshore 

and offshore, between July and 

November (Funk et al., 2010, 2011; 

Reiser et al., 2011; Aerts et al., 2013). 

After gray whales and bowhead whales, 

they are the most frequently sighted 

cetacean in the Chukchi Sea (Funk et 

al., 2011; Reiser et al., 2011). Shipboard 

visual line-transect surveys occurred 

biannually from 1999 to 2010, resulting 

in harbor porpoise abundance estimates 

for each survey. These surveys 

demonstrate the distribution of harbor 

porpoises throughout the Chukchi and 

Beaufort Seas but are not reliable for 

estimating abundance estimates in this 

region. 

Bearded seals are widely distributed 

throughout the summer and fall, 

following ice coverage northward, while 

juvenile seals remain near the coasts of 

the Bering and Chukchi Seas (Burns, 

1967, 1981; Heptner et al., 1976; Nelson, 

1981; Cameron et al., 2018). At this 

time, there is no reliable population 

estimate available for the entire Alaska 

stock of bearded seals. Recent aerial 

abundance surveys (Conn et al., 2014) 

used a sub-sample of data collected in 

the U.S. portion of the Bering Sea to 

calculate a partial abundance estimate 

of 301,836 seals (95 percent CI: 

238,195–371,147). Future studies plan 

to combine spring survey results of the 

Chukchi Sea and Beaufort Sea. 

Similarly, ringed seals also lack a 

reliable population estimate for the 

entire stock. Conn et al. (2014) 

calculated an abundance estimate of 

171,418 ringed seals (95 percent CI: 

141,588–201,090) using a sub-sample of 

data collected from the U.S. portion of 

the Bering Sea in 2012. Researchers plan 

to combine these results with those from 

spring surveys of the Chukchi and 

Beaufort Seas once complete. During the 

summer months, ringed seals forage 

along ice edges or in open water areas 

of high productivity and have been 

observed in the northern Beaufort Sea 

during summer months (Harwood and 

Stirling, 1992; Freitas et al., 2008; Kelly 

et al., 2010b; Harwood et al., 2015). This 

open water movement becomes limited 

with the onset of ice in the fall forcing 

the seals to move west and south as ice 

packs advance, dispersing the animals 

throughout the Chukchi and Bering 

Seas, with only a portion remaining in 

the Beaufort Sea (Frost and Lowry, 

1984; Crawford et al., 2012; Harwood et 

al., 2012). 

In addition to ringed and bearded 

seals, other pinniped species that could 

be encountered during the proposed 

survey include the ribbon seal and 

spotted seal. The ribbon seal is 

uncommon in the Chukchi Sea, and 

there are few sightings in the Beaufort 

Sea. From late March to early May, 

ribbon seals inhabit the Bering Sea ice 

front. They are most abundant in the 

northern part of the ice front in the 

central and western parts of the Bering 

Sea. As the ice recedes in May to midJuly, the seals move farther north in the 

Bering Sea, where they haul out on the 

receding ice edge and remnant ice. 

Spotted seals are more abundant in the 

Chukchi Sea and occur in small 

numbers in the Beaufort Sea. As the ice 

melts, seals become more concentrated, 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28793 

with part of the Bering Sea population 

moving to the Bering Strait and the 

southern part of the Chukchi Sea. The 

distribution of spotted seals is 

seasonally related to specific life-history 

events that can be broadly divided into 

two periods: Late-fall through spring, 

when whelping, nursing, breeding, and 

molting occur in association with the 

presence of sea ice on which the seals 

haul out, and summer through fall when 

seasonal sea ice has melted and most 

spotted seals use land for hauling out. 

Satellite-tagging studies showed that 

seals tagged in the northeastern Chukchi 

Sea moved south in October and passed 

through the Bering Strait in November. 

Seals overwintered in the Bering Sea 

along the ice edge and made east-west 

movements along the edge. In summer 

and fall, spotted seals use coastal haulout sites regularly and may be found as 

far north as 69–72° N in the Chukchi 

and Beaufort seas. Neither of these 

species would likely be encountered 

during the proposed activity other than 

perhaps during transit periods to or 

from the survey area. Although their 

encounters this far north in the Arctic 

are rare, authorization of take has been 

proposed at the request of the applicant. 

Clarke et al. (2015) described Biological 

Important Areas (BIAs) for cetaceans in 

the Arctic. BIAs were delineated for two 

baleen whale species, bowhead whales 

and gray whales, and one toothed 

whale, the beluga whale. The proposed 

UAGI survey areas do not coincide with 

any of the three Arctic BIAs. 

Unusual Mortality Events (UME) 

A UME is defined under the MMPA 

as ‘‘a stranding that is unexpected; 

involves a significant die-off of any 

marine mammal population; and 

demands immediate response.’’ For 

more information on UMEs, please visit: 

www.fisheries.noaa.gov/national/ 

marine-mammal-protection/marinemammal-unusual-mortality-events. 

Currently recognized UMEs in Alaska 

involving species under NMFS’ 

jurisdiction include those affecting ice 

seals in the Bering and Chukchi Seas 

and gray whales. Since June 1, 2018, 

elevated strandings for bearded, ringed 

and spotted seals have occurred in the 

Bering and Chukchi seas in Alaska, with 

causes undetermined. Through 2020, 

there were 315 recorded seal strandings. 

For more information, please visit: 

www.fisheries.noaa.gov/alaska/marinelife-distress/2018-2020-ice-seal-unusualmortality-event-alaska. 

Since January 1, 2019, elevated gray 

whale strandings have occurred along 

the west coast of North America from 

Mexico through Alaska. As of April 5, 

2021, there have been a total of 430 

whales reported in the event, with 

approximately 205 dead whales in 

Mexico, 209 whales in the United States 

(including 93 in Alaska), and 16 whales 

in British Columbia, Canada. For the 

United States, the historical 18-year 5- 

month average (Jan–May) is 14.8 whales 

for this same time-period. Several dead 

whales have been emaciated with 

moderate to heavy whale lice (cyamid) 

loads. Necropsies have been conducted 

on a subset of whales with additional 

findings of vessel strike in three whales 

and entanglement in one whale. In 

Mexico, 50–55 percent of the freeranging whales observed in the lagoons 

in winter have been reported as 

‘‘skinny’’ compared to the annual 

average of 10–12 percent ‘‘skinny’’ 

whales normally seen. The cause of the 

UME is as yet undetermined. For more 

information, please visit: 

www.fisheries.noaa.gov/national/ 

marine-life-distress/2019-2020-graywhale-unusual-mortality-event-alongwest-coast-and. 

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 

Revision to its Technical Guidance for 

Assessing the Effects of Anthropogenic 

Sound on Marine Mammal Hearing 

(Technical Guidance) (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, 

28794 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

please see NMFS (2018) for a review of 

available information. Thirteen marine 

mammal species (9 cetacean and 4 

pinniped (all phocid) species) have the 

reasonable potential to co-occur with 

the proposed survey activities. Please 

refer to Table 1. Of the cetacean species 

that may be present, 5 are classified as 

low-frequency cetaceans (i.e., all 

mysticete species), 3 are classified as 

mid-frequency cetaceans (i.e., all 

delphinid species), and 1 is classified as 

high-frequency cetacean (i.e., harbor 

porpoise). 

Potential Effects of Specified Activities 

on Marine Mammals and Their Habitat 

This section includes a summary of 

the ways that UAGI’s specified activity 

may impact marine mammals and their 

habitat. Detailed descriptions of the 

potential effects of similar specified 

activities have been provided in other 

recent Federal Register notices, 

including for survey activities using the 

same methodology and over a similar 

amount of time, and affecting similar 

species (e.g., 83 FR 29212, June 22, 

2018; 84 FR 14200, April 9, 2019; 85 FR 

19580, April 7, 2020). No significant 

new information is available, and we 

refer the reader to these documents for 

additional detail. The Estimated Take 

section includes a quantitative analysis 

of the number of individuals that are 

expected to be taken by UAGI’s activity. 

The Negligible Impact Analysis and 

Determination section considers the 

potential effects of the specified activity, 

the Estimated Take section, and the 

Proposed 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. 

Background on Active Acoustic Sound 

Sources and Acoustic Terminology 

This section contains a brief technical 

background on sound, on the 

characteristics of certain sound types, 

and on metrics used in this proposal 

inasmuch as the information is relevant 

to the specified activity and to the 

discussion of the effects of the specified 

activity on marine mammals in this 

document. For general information on 

sound and its interaction with the 

marine environment, please see, e.g., Au 

and Hastings (2008); Richardson et al. 

(1995); Urick (1983). 

Sound travels in waves, the basic 

components of which are frequency, 

wavelength, velocity, and amplitude. 

Frequency is the number of pressure 

waves that pass by a reference point per 

unit of time and is measured in hertz or 

cycles per second. Wavelength is the 

distance between two peaks or 

corresponding points of a sound wave 

(length of one cycle). Higher frequency 

sounds have shorter wavelengths than 

lower frequency sounds, and typically 

attenuate (decrease) more rapidly, 

except in certain cases in shallower 

water. Amplitude is the height of the 

sound pressure wave or the ‘‘loudness’’ 

of a sound and is typically described 

using the relative unit of the decibel. A 

sound pressure level (SPL) in dB is 

described as the ratio between a 

measured pressure and a reference 

pressure (for underwater sound, this is 

1 microPascal (mPa)), and is a 

logarithmic unit that accounts for large 

variations in amplitude. Therefore, a 

relatively small change in dB 

corresponds to large changes in sound 

pressure. The source level (SL) 

represents the SPL referenced at a 

distance of 1 m from the source 

(referenced to 1 mPa), while the received 

level is the SPL at the listener’s position 

(referenced to 1 mPa). 

Root mean square (rms) is the 

quadratic mean sound pressure over the 

duration of an impulse. Root mean 

square is calculated by squaring all of 

the sound amplitudes, averaging the 

squares, and then taking the square root 

of the average (Urick, 1983). Root mean 

square accounts for both positive and 

negative values; squaring the pressures 

makes all values positive so that they 

may be accounted for in the summation 

of pressure levels (Hastings and Popper, 

2005). This measurement is often used 

in the context of discussing behavioral 

effects, in part because behavioral 

effects, which often result from auditory 

cues, may be better expressed through 

averaged units than by peak pressures. 

Sound exposure level (SEL; 

represented as dB re 1 mPa2-s) represents 

the total energy in a stated frequency 

band over a stated time interval or event 

and considers both intensity and 

duration of exposure. The per-pulse SEL 

is calculated over the time window 

containing the entire pulse (i.e., 100 

percent of the acoustic energy). SEL is 

a cumulative metric; it can be 

accumulated over a single pulse, or 

calculated over periods containing 

multiple pulses. Cumulative SEL 

represents the total energy accumulated 

by a receiver over a defined time 

window or during an event. Peak sound 

pressure (also referred to as zero-to-peak 

sound pressure or 0–pk) is the 

maximum instantaneous sound pressure 

measurable in the water at a specified 

distance from the source and is 

represented in the same units as the rms 

sound pressure. 

When underwater objects vibrate or 

activity occurs, sound-pressure waves 

are created. These waves alternately 

compress and decompress the water as 

the sound wave travels. Underwater 

sound waves radiate in a manner similar 

to ripples on the surface of a pond and 

may be either directed in a beam or 

beams or may radiate in all directions 

(omnidirectional sources), as is the case 

for sound produced by the pile driving 

activity considered here. The 

compressions and decompressions 

associated with sound waves are 

detected as changes in pressure by 

aquatic life and man-made sound 

receptors such as hydrophones. 

Even in the absence of sound from the 

specified activity, the underwater 

environment is typically loud due to 

ambient sound, which is defined as 

environmental background sound levels 

lacking a single source or point 

(Richardson et al., 1995). The sound 

level of a region is defined by the total 

acoustical energy being generated by 

known and unknown sources. These 

sources may include physical (e.g., 

wind and waves, earthquakes, ice, 

atmospheric sound), biological (e.g., 

sounds produced by marine mammals, 

fish, and invertebrates), and 

anthropogenic (e.g., vessels, dredging, 

construction) sound. A number of 

sources contribute to ambient sound, 

including wind and waves, which are a 

main source of naturally occurring 

ambient sound for frequencies between 

200 hertz (Hz) and 50 kilohertz (kHz) 

(Mitson, 1995). In general, ambient 

sound levels tend to increase with 

increasing wind speed and wave height. 

Precipitation can become an important 

component of total sound at frequencies 

above 500 Hz, and possibly down to 100 

Hz during quiet times. Marine mammals 

can contribute significantly to ambient 

sound levels, as can some fish and 

snapping shrimp. The frequency band 

for biological contributions is from 

approximately 12 Hz to over 100 kHz. 

Sources of ambient sound related to 

human activity include transportation 

(surface vessels), dredging and 

construction, oil and gas drilling and 

production, geophysical surveys, sonar, 

and explosions. Vessel noise typically 

dominates the total ambient sound for 

frequencies between 20 and 300 Hz. In 

general, the frequencies of 

anthropogenic sounds are below 1 kHz 

and, if higher frequency sound levels 

are created, they attenuate rapidly. 

The sum of the various natural and 

anthropogenic sound sources that 

comprise ambient sound at any given 

location and time depends not only on 

the source levels (as determined by 

current weather conditions and levels of 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28795 

biological and human activity) but also 

on the ability of sound to propagate 

through the environment. In turn, sound 

propagation is dependent on the 

spatially and temporally varying 

properties of the water column and sea 

floor, and is frequency-dependent. As a 

result of the dependence on a large 

number of varying factors, ambient 

sound levels can be expected to vary 

widely over both coarse and fine spatial 

and temporal scales. Sound levels at a 

given frequency and location can vary 

by 10–20 dB from day to day 

(Richardson et al., 1995). The result is 

that, depending on the source type and 

its intensity, sound from the specified 

activity may be a negligible addition to 

the local environment or could form a 

distinctive signal that may affect marine 

mammals. Details of source types are 

described in the following text. 

Sounds are often considered to fall 

into one of two general types: Pulsed 

and non-pulsed (defined in the 

following). The distinction between 

these two sound types is important 

because they have differing potential to 

cause physical effects, particularly with 

regard to hearing (e.g., Ward, 1997 in 

Southall et al., 2007). Please see 

Southall et al. (2007) for an in-depth 

discussion of these concepts. The 

distinction between these two sound 

types is not always obvious, as certain 

signals share properties of both pulsed 

and non-pulsed sounds. A signal near a 

source could be categorized as a pulse, 

but due to propagation effects as it 

moves farther from the source, the 

signal duration becomes longer (e.g., 

Greene and Richardson, 1988). 

Pulsed sound sources (e.g., airguns, 

explosions, gunshots, sonic booms, 

impact pile driving) produce signals 

that are brief (typically considered to be 

less than one second), broadband, atonal 

transients (ANSI, 1986, 2005; Harris, 

1998; NIOSH, 1998; ISO, 2003) and 

occur either as isolated events or 

repeated in some succession. Pulsed 

sounds are all characterized by a 

relatively rapid rise from ambient 

pressure to a maximal pressure value 

followed by a rapid decay period that 

may include a period of diminishing, 

oscillating maximal and minimal 

pressures, and generally have an 

increased capacity to induce physical 

injury as compared with sounds that 

lack these features. 

Non-pulsed sounds can be tonal, 

narrowband, or broadband, brief or 

prolonged, and may be either 

continuous or intermittent (ANSI, 1995; 

NIOSH, 1998). Some of these nonpulsed sounds can be transient signals 

of short duration but without the 

essential properties of pulses (e.g., rapid 

rise time). Examples of non-pulsed 

sounds include those produced by 

vessels, aircraft, machinery operations 

such as drilling or dredging, vibratory 

pile driving, and active sonar systems. 

The duration of such sounds, as 

received at a distance, can be greatly 

extended in a highly reverberant 

environment. 

Airgun arrays produce pulsed signals 

with energy in a frequency range from 

about 10–2,000 Hz, with most energy 

radiated at frequencies below 200 Hz. 

The amplitude of the acoustic wave 

emitted from the source is equal in all 

directions (i.e., omnidirectional), but 

airgun arrays do possess some 

directionality due to different phase 

delays between guns in different 

directions. Airgun arrays are typically 

tuned to maximize functionality for data 

acquisition purposes, meaning that 

sound transmitted in horizontal 

directions and at higher frequencies is 

minimized to the extent possible. 

Summary on Specific Potential Effects 

of Acoustic Sound Sources 

Underwater sound from active 

acoustic sources can include one or 

more of the following: Temporary or 

permanent hearing impairment, nonauditory physical or physiological 

effects, behavioral disturbance, stress, 

and masking. The degree of effect is 

intrinsically related to the signal 

characteristics, received level, distance 

from the source, and duration of the 

sound exposure. Marine mammals 

exposed to high-intensity sound, or to 

lower-intensity sound for prolonged 

periods, can experience hearing 

threshold shift (TS), which is the loss of 

hearing sensitivity at certain frequency 

ranges (Finneran, 2015). TS can be 

permanent (PTS), in which case the loss 

of hearing sensitivity is not fully 

recoverable, or temporary (TTS), in 

which case the animal’s hearing 

threshold would recover over time 

(Southall et al., 2007). 

Animals in the vicinity of UAGI’s 

proposed seismic survey activity are 

unlikely to incur PTS due to the small 

estimated auditory injury zones, in 

conjunction with the anticipated 

efficacy of the proposed mitigation 

requirements. Please see Estimated Take 

and Proposed Mitigation for further 

discussion. 

Behavioral disturbance may include a 

variety of effects, including subtle 

changes in behavior (e.g., minor or brief 

avoidance of an area or changes in 

vocalizations), more conspicuous 

changes in similar behavioral activities, 

and more sustained and/or potentially 

severe reactions, such as displacement 

from or abandonment of high-quality 

habitat. Behavioral responses to sound 

are highly variable and context-specific 

and any reactions depend on numerous 

intrinsic and extrinsic factors (e.g., 

species, state of maturity, experience, 

current activity, reproductive state, 

auditory sensitivity, time of day), as 

well as the interplay between factors. 

Available studies show wide variation 

in response to underwater sound; 

therefore, it is difficult to predict 

specifically how any given sound in a 

particular instance might affect marine 

mammals perceiving the signal. 

In addition, sound can disrupt 

behavior through masking, or interfering 

with, an animal’s ability to detect, 

recognize, or discriminate between 

acoustic signals of interest (e.g., those 

used for intraspecific communication 

and social interactions, prey detection, 

predator avoidance, navigation). 

Masking occurs when the receipt of a 

sound is interfered with by another 

coincident sound at similar frequencies 

and at similar or higher intensity, and 

may occur whether the sound is natural 

(e.g., snapping shrimp, wind, waves, 

precipitation) or anthropogenic (e.g., 

shipping, sonar, seismic exploration) in 

origin. 

Sound may affect marine mammals 

through impacts on the abundance, 

behavior, or distribution of prey species 

(e.g., crustaceans, cephalopods, fish, 

zooplankton) (i.e., effects to marine 

mammal habitat). Prey species exposed 

to sound might move away from the 

sound source, experience TTS, 

experience masking of biologically 

relevant sounds, or show no obvious 

direct effects. The most likely impacts 

(if any) for most prey species in a given 

area would be temporary avoidance of 

the area. Surveys using active acoustic 

sound sources move through an area 

relatively quickly, limiting exposure to 

multiple pulses. In all cases, sound 

levels would return to ambient once a 

survey ends and the noise source is shut 

down and, when exposure to sound 

ends, behavioral and/or physiological 

responses are expected to end relatively 

quickly. Finally, the survey equipment 

will not have significant impacts to the 

seafloor and does not represent a source 

of pollution. 

Vessel Strike 

Vessel collisions with marine 

mammals, or ship strikes, can result in 

death or serious injury of the animal. 

These interactions are typically 

associated with large whales, which are 

less maneuverable than are smaller 

cetaceans or pinnipeds in relation to 

large vessels. The severity of injuries 

typically depends on the size and speed 

of the vessel, with the probability of 

28796 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

death or serious injury increasing as 

vessel speed increases (Knowlton and 

Kraus, 2001; Laist et al., 2001; 

Vanderlaan and Taggart, 2007; Conn 

and Silber, 2013). Impact forces increase 

with speed, as does the probability of a 

strike at a given distance (Silber et al., 

2010; Gende et al., 2011). The chances 

of a lethal injury decline from 

approximately 80 percent at 15 kn to 

approximately 20 percent at 8.6 kn. At 

speeds below 11.8 kn, the chances of 

lethal injury drop below 50 percent 

(Vanderlaan and Taggart, 2007). 

Ship strikes generally involve 

commercial shipping, which is much 

more common in both space and time 

than is geophysical survey activity and 

which typically involves larger vessels 

moving at faster speeds. Jensen and 

Silber (2004) summarized ship strikes of 

large whales worldwide from 1975– 

2003 and found that most collisions 

occurred in the open ocean and 

involved large vessels (e.g., commercial 

shipping). Commercial fishing vessels 

were responsible for three percent of 

recorded collisions, while no such 

incidents were reported for geophysical 

survey vessels during that time period. 

For vessels used in geophysical 

survey activities, vessel speed while 

towing gear is typically only 4–5 knots. 

At these speeds, both the possibility of 

striking a marine mammal and the 

possibility of a strike resulting in 

serious injury or mortality are so low as 

to be discountable. At average transit 

speed for geophysical survey vessels 

(approximately 10 kn), the probability of 

serious injury or mortality resulting 

from a strike (if it occurred) is less than 

50 percent (Vanderlaan and Taggart, 

2007; Conn and Silber, 2013). However, 

the likelihood of a strike actually 

happening is again low given the 

smaller size of these vessels and 

generally slower speeds. We anticipate 

that vessel collisions involving seismic 

data acquisition vessels towing gear, 

while not impossible, represent 

unlikely, unpredictable events for 

which there are no preventive measures. 

Given the required mitigation measures, 

the relatively slow speeds of vessels 

towing gear, the presence of bridge crew 

watching for obstacles at all times 

(including marine mammals), the 

presence of marine mammal observers, 

and the small number of seismic survey 

cruises relative to commercial ship 

traffic, we believe that the possibility of 

ship strike is discountable and, further, 

that were a strike of a large whale to 

occur, it would be unlikely to result in 

serious injury or mortality. No 

incidental take resulting from ship 

strike is anticipated or proposed for 

authorization, and this potential effect 

of the specified activity will not be 

discussed further in the following 

analysis. 

The potential effects of UAGI’s 

specified survey activity are expected to 

be limited to Level B behavioral 

harassment. No permanent auditory 

effects, or significant impacts to marine 

mammal habitat, including prey, are 

expected. 

Estimated Take 

This section provides an estimate of 

the number of incidental takes proposed 

for authorization 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 would be by Level B 

harassment, as use of seismic airguns 

may result, either directly or as a result 

of TTS, in disruption of behavioral 

patterns of marine mammals. The 

proposed mitigation and monitoring 

measures are expected to minimize the 

severity of such taking to the extent 

practicable. Moreover, based on the 

nature of the activity and the 

anticipated effectiveness of the 

mitigation measures (i.e., 

implementation of extended shutdown 

distances for certain species)— 

discussed in detail below in the 

Proposed Mitigation section—Level A 

harassment is neither anticipated nor 

proposed to be authorized. 

As described previously, no mortality 

is anticipated or proposed to be 

authorized for this activity. Below we 

describe how the take is estimated. 

Generally speaking, we estimate take 

by considering: (1) Acoustic thresholds 

above which NMFS believes the best 

available science indicates marine 

mammals will be behaviorally harassed 

or incur some degree of permanent 

hearing impairment; (2) the area or 

volume of water that will be ensonified 

above these levels in a day; (3) the 

density or occurrence of marine 

mammals within these ensonified areas; 

and, (4) and the number of days of 

activities. We note that while these 

basic factors can contribute to a basic 

calculation to provide an initial 

prediction of takes, additional 

information that can qualitatively 

inform take estimates is also sometimes 

available (e.g., previous monitoring 

results or average group size). Below, we 

describe the factors considered here in 

more detail and present the proposed 

take estimate. 

Acoustic Thresholds 

NMFS recommends the use of 

acoustic thresholds that identify the 

received level of underwater sound 

above which exposed marine mammals 

would be reasonably expected to be 

behaviorally harassed (equated to Level 

B harassment) or to incur PTS of some 

degree (equated to Level A harassment). 

Level B Harassment 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), the receiving animals 

(hearing, motivation, experience, 

demography, behavioral context), and 

the distance between the sound source 

and the animal, and can be difficult to 

predict (Southall et al., 2007, Ellison et 

al., 2012). NMFS uses a generalized 

acoustic threshold based on received 

level to estimate the onset of behavioral 

harassment. NMFS predicts that marine 

mammals may be behaviorally harassed 

(i.e., Level B harassment) when exposed 

to underwater anthropogenic noise 

above received levels 160 dB re 1 mPa 

(rms) for the impulsive sources (i.e., 

seismic airguns) evaluated here. 

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). UAGI’s proposed seismic 

survey includes the use of impulsive 

sources (seismic airgun). 

These thresholds are provided in 

Table 3 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. 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28797 

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. 

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 acoustic propagation modeling. 

The acoustic propagation modeling 

methodologies are described in greater 

detail in Appendix A of UAGI’s IHA 

application. The proposed survey would 

primarily acquire data using the 2- 

airgun array with a total discharge 

volume of 1,040 in3 and an 

approximately 15-second shot interval. 

During approximately 12 percent of the 

planned survey tracklines, the 6-airgun, 

3,120 in3 array would be used with a 60- 

second shot interval. All tracklines 

would be surveyed with a maximum 

tow depth of 9 m. The modeling 

assumed an airgun firing pressure of 

2,540 psi. Propagation modeling for 

UAGI’s application follows the 

approach used by the Lamont-Doherty 

Earth Observatory (L–DEO) for other, 

similar IHA applications. L–DEO uses 

ray tracing for the direct wave traveling 

from the array to the receiver and its 

associated source ghost (reflection at the 

air-water interface in the vicinity of the 

array), in a constant-velocity half-space 

(infinite homogeneous ocean layer, 

unbounded by a seafloor). To validate 

the model results, L–DEO measured 

propagation of pulses from a 36-airgun 

array at a tow depth of 6 m in the Gulf 

of Mexico, for deep water (∼1,600 m), 

intermediate water depth on the slope 

(∼600–1,100 m), and shallow water (∼50 

m) (Tolstoy et al., 2009; Diebold et al., 

2010). 

L–DEO collected a MCS data set from 

R/V Marcus G. Langseth (with the same 

36-airgun array referenced above) on an 

8 km streamer in 2012 on the shelf of 

the Cascadia Margin off of Washington 

in water up to 200 m deep that allowed 

Crone et al. (2014) to analyze the 

hydrophone streamer (>1,100 individual 

shots). These empirical data were then 

analyzed to determine in situ sound 

levels for shallow and upper 

intermediate water depths. These data 

suggest that modeled radii were 2–3 

times larger than the measured radii in 

shallow water. Similarly, data collected 

by Crone et al. (2017) during a survey 

off New Jersey in 2014 and 2015 

confirmed that in situ measurements 

collected by R/V Langseth hydrophone 

streamer were 2–3 times smaller than 

the predicted radii. 

L–DEO model results are used to 

determine the assumed radial distance 

to the 160–dB rms threshold for these 

arrays in deep water (>1,000 m) (down 

to a maximum water depth of 2,000 m) 

(see Table 4). Water depths in the 

project area may be up to 4,000 m, but 

marine mammals in the region are 

generally not anticipated to dive below 

2,000 m (Costa and Williams, 1999). The 

radii for intermediate water depths 

(100–1000 m) are derived from the 

deep-water ones by applying a 

correction factor (multiplication) of 1.5. 

No survey effort would occur in water 

depths <100 m. 

The area expected to be ensonified 

was determined by entering the planned 

survey lines into a GIS and then 

‘‘buffering’’ the lines by the applicable 

160–dB distance (see Appendix B in 

IHA application). The resulting 

ensonified areas were then increased by 

25% to allow for any necessary 

additional operations, such as resurveying segments where data quality 

was insufficient. This approach assumes 

that no marine mammals would move 

away or toward the trackline in 

response to increasing sound levels 

before the levels reach the threshold as 

R/V Sikuliaq approaches. 

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) 

6 airgun array; 3,120 in3 .............................................. 9 >1,000 ........................................................................... 1 4,640 

100–1,000 ..................................................................... 3 6,960 

2 airgun array; 1,040 in3 .............................................. 9 >1,000 ........................................................................... 1 1,604 

100–1,000 ..................................................................... 2 2,406 

1 Distance based on L–DEO model results. 

2Based on L–DEO model results with 1.5x correction factor applied. 

28798 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

Predicted distances to Level A 

harassment isopleths, which vary based 

on marine mammal hearing groups, 

were calculated based on L–DEO 

modeling performed 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 

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 

were derived from calculating the 

modified far-field signature. The farfield 

signature is often used as a theoretical 

representation of the source level. To 

compute the farfield signature, the 

source level is estimated at a large 

distance below the array (e.g., 9 km), 

and this level is back projected 

mathematically to a notional distance of 

1 m from the array’s geometrical center. 

However, when the source is an array of 

multiple airguns separated in space, the 

source level from the theoretical farfield 

signature is not necessarily the best 

measurement of the source level that is 

physically achieved at the source 

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

short ranges, distances <1 km), the 

pulses of sound pressure from each 

individual airgun in the source array do 

not stack constructively, as they do for 

the theoretical farfield signature. The 

pulses from the different airguns spread 

out in time such that the source levels 

observed or modeled are the result of 

the summation of pulses from a few 

airguns, not the full array (Tolstoy et al., 

2009). At larger distances, away from 

the source array center, sound pressure 

of all the airguns in the array stack 

coherently, but not within one time 

sample, resulting in smaller source 

levels (a few dB) than the source level 

derived from the farfield signature. 

Because the farfield signature does not 

take into account the large array effect 

near the source and is calculated as a 

point source, the modified farfield 

signature is a more appropriate measure 

of the sound source level for distributed 

sound sources, such as airgun arrays. 

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 (modeled in 1 Hz bands) 

were 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 source 

velocities and shot intervals specific to 

the planned survey, potential radial 

distances to auditory injury zones were 

then calculated for SELcum thresholds. 

For full detail of the modeling 

methodology used for estimating 

distance to Level A harassment peak 

pressure and cumulative SEL criteria, 

please see Appendix A of UAGI’s 

application. 

Inputs to the User Spreadsheets in the 

form of estimated source levels are 

shown in Appendix A of UAGI’s 

application. User Spreadsheets used by 

UAGI 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). 

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 Phocids 

6-airgun array (3,120 in3) ................. SELcum ............................................. 51 0 0 0 

Peak ................................................. 30 7 212 34 

2-airgun array (1,040 in3) ................. SELcum ............................................. 17 0 0 0 

Peak ................................................. 10 3 73 2 

Note that because of some of the 

assumptions included in the methods 

used (e.g., stationary receiver with no 

vertical or horizontal movement in 

response to the acoustic source), 

isopleths produced may be 

overestimates to some degree, which 

will ultimately result in some degree of 

overestimation of Level A harassment. 

However, these tools offer the best way 

to predict appropriate isopleths when 

more sophisticated modeling methods 

are not available. NMFS continues to 

develop ways to quantitatively refine 

these tools and will qualitatively 

address the output where appropriate. 

For mobile sources, such as the 

proposed seismic survey, the User 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28799 

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 and low-frequency 

cetaceans given very small modeled 

zones of injury for those species (all 

estimated zones less than 10 m for midfrequency cetaceans, up to a maximum 

of 51 m for low-frequency cetaceans and 

34 m for phocid pinnipeds), in context 

of distributed source dynamics. 

Similarly, for high-frequency cetaceans, 

the maximum modeled injury zone for 

the low-energy array (88 percent of 

survey effort) is 73 m and auditory 

injury would be unlikely to occur 

during use of that array. The source 

level of the array is a theoretical 

definition assuming a point source and 

measurement in the far-field of the 

source (MacGillivray, 2006). As 

described by Caldwell and Dragoset 

(2000), an array is not a point source, 

but one that spans a small area. In the 

far-field, individual elements in arrays 

will effectively work as one source 

because individual pressure peaks will 

have coalesced into one relatively broad 

pulse. The array can then be considered 

a ‘‘point source.’’ For distances within 

the near-field, i.e., approximately 2–3 

times the array dimensions, pressure 

peaks from individual elements do not 

arrive simultaneously because the 

observation point is not equidistant 

from each element. The effect is 

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 estimated 

Level A harassment isopleth distances 

would in all cases (other than for highfrequency cetaceans) be expected to be 

within the near-field of the array where 

the definition of source level breaks 

down. Therefore, actual locations 

within this distance of the array center 

where the sound level exceeds relevant 

harassment criteria would not 

necessarily exist. 

In consideration of the received sound 

levels in the near-field as described 

above, we expect the potential for Level 

A harassment of low- and midfrequency cetaceans 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. A similar conclusion may 

be drawn for high-frequency cetaceans 

relative to use of the low-energy airgun 

array. We do not believe that Level A 

harassment is a likely outcome for any 

low- or mid-frequency cetacean or 

phocid pinniped and do not propose to 

authorize any Level A harassment for 

these species. For high-frequency 

cetaceans, the larger estimated Level A 

harassment zone associated with the 

high-energy array would be present for 

only 12 percent of total survey effort, 

and given the expected rarity of 

occurrence for harbor porpoise, no 

incidents of Level A harassment are 

expected. 

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. 

Density values are shown in Table 6. 

Cetacean densities in the U.S. Arctic 

were published by Schick et al. (2017). 

This study used line-transect aerial 

survey data from ASAMM collected in 

the U.S. Chukchi and Beaufort seas from 

2000–2016 and associated habitat 

covariates to estimate abundance 

monthly within 10 km x 10 km grid 

cells (equivalent to a density in units of 

individuals/100km2). Estimates were 

produced for bowhead, gray, and beluga 

whales, as well as other baleen whales 

such as fin, humpback, and minke 

whales. The spatial extent of the model 

predictions differed by species, but for 

all species other than bowhead whale 

and beluga whale was further south 

than the planned location of the UAGI 

survey. In general, marine mammals are 

expected to be encountered more 

frequently to the south of the proposed 

survey location. Therefore, estimated 

take numbers produced through use of 

the density model products are expected 

to be a very conservative estimate. 

Previous monitoring reports from recent 

Arctic surveys using the same research 

vessel saw a total of three humpback 

whales, 1 spotted seal, 4 unknown seals 

(Please see the following link for more 

detailed information on this monitoring 

report: https://media.fisheries.noaa.gov/ 

dam-migration/onr_arcticresearch_

2018iha_monrep_opr1.pdf). 

Furthermore, based on tagged surveys 

from the summer and fall, bowhead 

whales migrate across the continental 

shelf of Alaska in the Beaufort Sea to the 

central Chukchi Sea in September and 

remain in this area for the fall 

(Quakenbush, Small & Citta, 2013). Only 

one whale was reported to travel north 

towards the proposed survey area. With 

this information in mind, NMFS 

believes that the proposed take numbers 

conservatively estimate the number of 

bowhead whales that will be 

encountered during the proposed 

activity. 

For all species, except for beluga 

whales, UAGI extended the Schick et al. 

(2017) density values to calculate 

predictions for areas farther north. The 

spatial coverage of density estimates for 

bowhead whales extends northward to 

∼74 °N, which overlaps with the 

southern-most survey lines by ∼25 km. 

However, the majority of the survey 

lines do not overlap with spatial 

coverage of the Schick et al. (2017) 

density estimates, so the following 

method was used to produce a 

conservative estimate of average 

bowhead density farther north. The two 

northern-most rows of 10km x 10km 

grid cells (ie., northern 20 km of 

estimates) and the two additional cells 

overlapped by the southern-most survey 

lines were selected from the bowhead 

whale GIS raster files for August and 

September between 140°W and 165°W, 

the approximate east-west extent of the 

survey lines. Density estimates within 

those cells were then evaluated and 

cells east of ∼157°W were excluded as 

they contained densities that were 

effectively zero which would reduce the 

calculated average. The mean of the 

remaining cells (west of 157°W) was 

then calculated. 

The same process was used to 

calculate densities for gray whales, fin 

whales, humpback whales, and minke 

whales. However the northern survey 

coverage from Schick et al. (2017) for 

these species extends only to ∼73°N. 

This meant that there was no overlap 

with any of the survey lines and no 

additional cells beyond the two 

northernmost rows (20km) were used in 

the calculations. The resulting density 

estimates were extremely small. 

For beluga whales, the spatial 

coverage of the Schick et al. (2017) 

density estimates overlapped the full 

extent of the survey lines and associated 

ensonified areas. To calculate an 

average beluga whale density in areas 

that may be exposed above threshold 

levels, UAGI selected all grid cells from 

the August and September estimates 

that overlapped (wholly or partially) 

with estimated the 160 dB ensonified 

area around the planned tracklines and 

calculated the mean. 

During ASAMM, sightings of 

pinnipeds were recorded when possible 

and the resulting data were used by 

Schick et al. (2017) to produce habitatbased estimates in the same manner as 

cetaceans. However, given ASAMM was 

designed for large whales, including 

typically being flown at altitudes above 

304.8 feet (ft) ASL, and small pinniped 

sightings may not have been recorded as 

consistently, the Schick et al (2017) 

pinniped densities were not used in this 

analysis. Instead, bearded and ringed 

seal densities from NMFS’s Biological 

Opinion for the Navy’s Arctic Research 

28800 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

Activities 2018–2021 were used (NMFS 

2019b), which were based on habitatbased modeling by Kaschner et al. 

(2006) and Kaschner (2004). 

Spotted and ribbon seals were not 

included in NMFS (2019b). Thus, 

spotted seal densities were estimated by 

multiplying the ringed seal density by 

the ratio of the estimated Chukchi Sea 

populations of the two species. The best 

estimate of the Alaskan population of 

spotted seals is 461,625 (Muto et al., 

2020), and ∼8% of the population 

(∼37,000) is estimated to be present in 

the Chukchi Sea during the summer and 

fall (Rugh et al., 1997). As the best 

estimate of the population of ringed 

seals in the Alaskan Chukchi Sea is 

∼208,000 animals (Bengtson et al., 

2005), this resulted in a ratio of 0.18. 

Based on Hartin et al., (2013), four 

ribbon seal sightings were reported 

during vessel operations in the Chukchi 

Sea from 2006 through 2010, resulting 

in a density estimate of 0.0007/km2. 

Highly variable oceanographic and 

atmospheric conditions determine the 

distribution of sea ice in the Arctic, 

which heavily influences the species 

and number of marine mammals 

potentially present at these high 

latitudes. Thus, there is considerable 

year-to-year variation in the distribution 

and abundance of the marine mammal 

species in the survey area. For some 

species, the densities derived from past 

surveys may not be representative of the 

densities that would be encountered 

during the proposed seismic surveys. 

However, the approach used here is 

based on the best available data. 

TABLE 6—DENSITY VALUES USED FOR

TAKE ANALYSIS, CALCULATED BY

UAGI 

Species Density 

(individuals/km2) 

Bowhead whale ............ 0.0124. 

Gray whale ................... 0. 

Fin whale ...................... 0. 

Humpback whale .......... 0. 

Minke whale ................. 0. 

Beluga whale ................ 0.0255. 

Killer whale ................... Unknown. 

Narwhal ........................ Unknown. 

Harbor porpoise ........... Unknown. 

Bearded seal ................ 0.0332. 

Ribbon seal .................. 0.0677. 

Ringed seal .................. 0.376. 

Spotted seal ................. 0.0007. 

Take Calculation and Estimation 

Here we describe how the information 

provided above is brought together to 

produce a quantitative take estimate. In 

order to estimate the number of marine 

mammals predicted to be exposed to 

sound levels that would result in Level 

A or Level B harassment, radial 

distances from the airgun array to 

predicted isopleths corresponding to the 

Level A harassment and Level B 

harassment thresholds are calculated, as 

described above. Those radial distances 

are then used to calculate the area(s) 

around the airgun array predicted to be 

ensonified to sound levels that exceed 

the Level A and Level B harassment 

thresholds. The distance for the 160-dB 

threshold (based on L–DEO model 

results) was used to draw a buffer 

around every transect line in GIS to 

determine the total ensonified area in 

each depth category. Estimated 

incidents of exposure above Level A and 

Level B harassment criteria are 

presented in Table 7. As noted 

previously, UAGI has added 25 percent 

in the form of operational days, which 

is equivalent to adding 25 percent to the 

proposed line-kilometers to be 

surveyed. This accounts for the 

possibility that additional operational 

days are required, and is included in the 

estimates of actual exposures. 

The number of individual marine 

mammals potentially exposed to airgun 

sounds with received levels ≥ 160 dB re 

1 mParms (Level B) was estimated 

following NSF’s take calculation 

method by multiplying the estimated 

densities by the total area expected to be 

ensonified above the Level threshold. 

The total ensonified area was multiplied 

by 25 percent to account for any 

necessary additional operations, such as 

re-surveying segments where data 

quality was insufficient. This approach 

assumes that no marine mammals 

would move away or toward the 

trackline in response to increasing 

sound levels before the levels reach the 

threshold as R/V Sikuliaq approaches. 

This value was then multiplied by the 

estimated densities for each species to 

produce estimated Level B takes. Given 

the location of the survey being far 

north in the Arctic, we expect that the 

density values, and thus estimated take 

numbers, are conservative estimates of 

what is likely to be encountered during 

the survey. 

TABLE 7—ESTIMATED TAKING BY LEVEL A AND LEVEL B HARASSMENT, AND PERCENTAGE OF POPULATION

Species Stock 1

Estimated 

Level B 

harassment 

Estimated 

Level A 

harassment 

Proposed 

Level B 

harassment 

Proposed 

Level A 

harassment 

Total take Percent of 

stock 1

Bowhead whale ..... Western Arctic ...... 339 3 342 0 342 2.03 

Humpback whale 2 WN Pacific ............ 0 0 2 0 2 0.00 

Fin whale 2 4 .......... NE Pacific ............. 0 0 2 0 2 0.00 

Gray whale 2 .......... EN Pacific ............. 0 0 2 0 2 0.00 

Minke whale 2 4 ...... Alaska ................... 0 0 2 0 2 0.00 

Beluga whale ........ Beaufort Sea ........ 696 7 703 0 703 1.34 

Eastern Chukchi.

Killer whale 2 ......... Alaska Resident ... 0 0 6 0 6 0.00 

Narwhal 3 4 ............. Unidentified ........... 0 0 2 0 2 n/a 

Harbor porpoise 2 4 Bering Sea ............ 0 0 2 0 2 0.00 

Bearded seal ......... Beringia ................ 907 9 916 0 916 0.73 

Ringed seal ........... Arctic ..................... 10,268 105 10,373 0 10,373 6.05 

Spotted seal .......... Bering ................... 19 0 19 0 19 0.00 

Ribbon seal ........... Unidentified ........... 1849 19 1868 0 1868 1.01 

1 In most cases, where multiple stocks are being affected, for the purposes of calculating the percentage of the stock impacted, the take is 

being analyzed as if all proposed takes occurred within each stock. Where necessary, additional discussion is provided in the ‘‘Small Numbers 

Analysis’’ section. 2 UAGI requests authorization of gray whale, humpback whale, fin whale, minke whale, killer whale, and harbor porpoise take equivalent to exposure of one group (Clarke et al., 2016; Clarke et al., 2017; Clarke et al., 2018; Clarke et al., 2019). 3 UAGI requests authorization of two takes of narwhals. 

4As noted in Table 1, there is no estimate of abundance available for these species. See ‘‘Small Numbers Analysis’’ section for further 

discussion. 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28801 

Although, gray whales, fin whales, 

humpback whales, minke whales, 

narwhals and harbor porpoises are not 

expected to occur this far north in the 

Arctic, we agree with NSF that there is 

possibility that the proposed activity 

might encounter these species and thus 

a conservative number of takes based on 

average group size from yearly Aerial 

Surveys of Arctic Marine Mammals 

(ASAMM) (Clark et al., 2016, 2017, 

2018, 2019) has been proposed. 

Proposed 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. 

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, as well as 

subsistence uses. This considers the 

nature of the potential adverse impact 

being mitigated (likelihood, scope, 

range). It further considers the 

likelihood that the measure will be 

effective if implemented (probability of 

accomplishing the mitigating result if 

implemented as planned), the 

likelihood of effective implementation 

(probability implemented as planned), 

and; 

(2) The practicability of the measures 

for applicant implementation, which 

may consider such things as cost and 

impact on operations. 

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. 

Due to the use of high- and lowenergy airgun arrays used within this 

survey, two separate mitigation 

protocols are proposed for use 

throughout the activity depending on 

which array is in use (Table 8). 

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 EZ, within which 

observation of certain marine mammals 

requires shutdown of the acoustic 

source, but also a buffer zone. 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-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 standard 

EZ is 500 m from the edges of the airgun 

array for high energy surveys and 100 m 

for low energy surveys. For high energy 

surveys, 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). For low 

energy surveys, the buffer zone 

encompasses the area at and below the 

sea surface from the edge of the 0–100 

m EZ, out to a radius of 200 m from the 

edges of the airgun array (100–200 m). 

Visual monitoring of the EZ and 

buffer zones 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 naı ̈ve marine 

mammals that may be in the area during 

pre-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. 

UAGI 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 PSOs aboard 

the vessel must have a minimum of 90 

days at-sea experience working in the 

roles, with no more than 18 months 

elapsed since the conclusion of the atsea experience. One visual PSO with 

such experience shall be designated as 

the lead for the entire protected species 

observation team. The lead PSO shall 

serve as primary point of contact for the 

vessel operator and ensure all PSO 

requirements per the IHA are met. To 

the maximum extent practicable, the 

experienced PSOs should be scheduled 

to be on duty with those PSOs with 

appropriate training but who have not 

yet gained relevant experience. 

During survey operations (e.g., any 

day on which use of the acoustic source 

is planned to occur, and whenever the 

acoustic source is in the water, whether 

activated or not), a minimum of two 

visual PSOs must be on duty and 

conducting visual observations at all 

times during daylight hours (i.e., from 

30 minutes prior to sunrise through 30 

minutes following sunset). Visual 

monitoring of the EZ and buffer zone 

must begin no less than 30 minutes 

prior to ramp-up and must continue 

until one hour after use of the acoustic 

source ceases or until 30 minutes past 

sunset. Visual PSOs shall 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. 

28802 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

PSOs shall establish and monitor the 

EZ and buffer zone. These zones shall 

be based upon the radial distance from 

the edges of the acoustic source (rather 

than being based on the center of the 

array or around the vessel itself). During 

use of the acoustic source (i.e., anytime 

airguns are active, including ramp-up), 

detections of marine mammals within 

the buffer zone (but outside the EZ) 

shall be communicated to the operator 

to prepare for the potential shutdown of 

the acoustic source. 

During use of the airgun (i.e., anytime 

the acoustic source is active, including 

ramp-up), detections of marine 

mammals within the buffer zone (but 

outside the EZ) should be 

communicated to the operator to 

prepare for the potential shutdown of 

the acoustic source. Visual PSOs will 

immediately communicate all 

observations to the on duty acoustic 

PSO(s), including any determination by 

the PSO regarding species 

identification, distance, and bearing and 

the degree of confidence in the 

determination. Any observations of 

marine mammals by crew members 

shall be relayed to the PSO team. During 

good conditions (e.g., daylight hours; 

Beaufort sea state (BSS) 3 or less), visual 

PSOs shall conduct observations when 

the acoustic source is not operating for 

comparison of sighting rates and 

behavior with and without use of the 

acoustic source and between acquisition 

periods, to the maximum extent 

practicable. 

Visual PSOs may be on watch for a 

maximum of four consecutive hours 

followed by a break of at least one hour 

between watches and may conduct a 

maximum of 12 hours of observation per 

24-hour period. Combined observational 

duties (visual and acoustic but not at 

same time) may not exceed 12 hours per 

24-hour period for any individual PSO. 

Establishment of Exclusion and Buffer 

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 behavioral 

patterns. The PSOs would establish a 

minimum EZ with a 500- or 100-m 

radius, during use of the high energy 

and low energy arrays, respectively, for 

all species except bowhead whales. The 

EZ would 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). 

The EZs are intended to be 

precautionary in the sense that they 

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, the EZs are 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 

these distances are likely regularly 

attainable for PSOs using the naked eye 

during typical conditions. 

An extended EZ of 1,500/500 m must 

be implemented for all bowhead whales 

during high energy and low energy 

survey effort, respectively, because of 

their importance to subsistence hunters 

and protected status. No buffer of this 

extended EZ is required. 

Pre-Clearance and Ramp-Up 

Ramp-up (sometimes referred to as 

‘‘soft start’’) means the gradual and 

systematic increase of emitted sound 

levels from an airgun array. Ramp-up 

begins by first activating a single airgun 

of the smallest volume, followed by 

doubling the number of active elements 

in stages until the full complement of an 

array’s airguns are active. Each stage 

should be approximately the same 

duration, and the total duration should 

not be less than approximately 20 

minutes for high energy airgun arrays. 

Ramp-up for the low energy array, 

which includes only two elements, may 

be shorter. The intent of pre-clearance 

observation (30 minutes) is to ensure no 

protected species are observed within 

the buffer zone prior to the beginning of 

ramp-up. During pre-clearance is the 

only time observations of protected 

species in the buffer zone would 

prevent operations (i.e., the beginning of 

ramp-up). The intent of ramp-up is to 

warn protected species of pending 

seismic operations and to allow 

sufficient time for those animals to leave 

the immediate vicinity. A ramp-up 

procedure, involving a step-wise 

increase in the number of airguns 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-clearance 

and ramp-up requirements: 

• The operator must notify a 

designated PSO of the planned start of 

ramp-up as agreed upon with the lead 

PSO; the notification time should not be 

less than 60 minutes prior to the 

planned ramp-up in order to allow the 

PSOs time to monitor the EZ and buffer 

zone for 30 minutes prior to the 

initiation of ramp-up (pre-clearance); 

• Ramp-ups shall be scheduled so as 

to minimize the time spent with the 

source activated prior to reaching the 

designated run-in; 

• One of the PSOs conducting preclearance 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 

EZ or buffer zone. If a marine mammal 

is observed within the applicable EZ or 

the buffer zone during the 30 minute 

pre-clearance period, ramp-up may not 

begin until the animal(s) has been 

observed exiting the zones or until an 

additional time period has elapsed with 

no further sightings (15 minutes for 

small odontocetes and pinnipeds, and 

30 minutes for all mysticetes and all 

other odontocetes, including large 

delphinids, such as beluga whales and 

killer whales); 

• Ramp-up shall begin by activating a 

single airgun of the smallest volume in 

the array and shall continue in stages by 

doubling the number of active elements 

at the commencement of each stage, 

with each stage of approximately the 

same duration. Duration shall not be 

less than 20 minutes for high energy 

arrays. The operator must provide 

information to the PSO documenting 

that appropriate procedures were 

followed; 

• PSOs must monitor the relevant EZ 

and buffer zone during ramp-up, and 

ramp-up must cease and the source 

must be shut down upon detection of a 

marine mammal within the applicable 

EZ. Once ramp-up has begun, detections 

of marine mammals within the buffer 

zone do not require shutdown, but such 

observation shall be communicated to 

the operator to prepare for the potential 

shutdown; 

• 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 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28803 

have occurred within the applicable EZ. 

For any longer shutdown, pre-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, preclearance 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-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 the airgun 

array is active (i.e., anytime one or more 

airguns is active, including during 

ramp-up) and a marine mammal appears 

within or enters the applicable EZ, the 

acoustic source will be shut down. 

When shutdown is called for by a PSO, 

the acoustic source will be immediately 

deactivated and any dispute resolved 

only following deactivation. 

Following a shutdown, airgun activity 

would not resume until the marine 

mammal has cleared the EZ. The animal 

would be considered to have cleared the 

EZ if it is visually observed to have 

departed the EZ, or it has not been seen 

within the EZ for 15 min in the case of 

small odontocetes and pinnipeds, or 30 

min in the case of mysticetes and large 

odontocetes, including beluga whales 

and killer whales. 

Upon implementation of shutdown, 

the source may be reactivated after the 

marine mammal(s) has been observed 

exiting the applicable EZ (i.e., animal is 

not required to fully exit the buffer zone 

where applicable) or following 15 

minutes for small odontocetes and 

pinnipeds, and 30 minutes for 

mysticetes and all other odontocetes, 

including beluga whales and killer 

whales, with no further observation of 

the marine mammal(s). 

UAGI must implement shutdown if a 

marine mammal species for which take 

was not authorized, or a species for 

which authorization was granted but the 

takes have been met, approaches the 

Level A or Level B harassment zones. L– 

DEO must also implement shutdown if 

any of the following are observed at any 

distance: 

• Any large whale (defined as any 

mysticete species) with a calf (defined 

as an animal less than two-thirds the 

body size of an adult observed to be in 

close association with an adult); and/or 

• An aggregation of six or more large 

whales. 

Passive Acoustic Monitoring (PAM) 

NMFS does not propose to require use 

of PAM for this activity. NMFS typically 

recommends use of PAM as part of 

prescribed mitigation requirements for 

high energy surveys, but not for low 

energy surveys, which here comprise 

approximately 88 percent of the 

planned survey. Therefore, PAM would 

only be applicable to the small portion 

of the proposed survey (12 percent) 

using the high-energy array. In addition, 

use of towed PAM is not generally 

expected to be effective in detecting 

mysticetes, due to overlap in the 

frequencies of mysticete vocalizations 

with the noise from the airgun array as 

well as from the vessel itself and flow 

noise around the towed PAM receiver. 

Species of greatest interest in 

prescribing use of towed PAM (e.g., 

sperm whales, beaked whales) are not 

present in the planned survey area. 

Further, UAGI has indicated that it 

would not be practicable to carry the 

additional monitoring personnel 

required for implementation of towed 

PAM. The R/V Sikuliaq is a smaller 

research vessel with limited space. 

TABLE 8—PROPOSED MITIGATION PROTOCOLS FOR HIGH- AND LOW-ENERGY ARRAYS

Mitigation Protocols 

Sources ................................ High Energy (6-airgun array with 3120 in3 total discharge volume).Low Energy (2-airgun array with 1040 in3 total discharge volume). 

Visual PSOs ......................... Minimum of 2 NMFS-approved PSOs on duty during 

daylight hours (30 minutes before sunrise through 30 

minutes after sunset); Limit of 2 consecutive hours 

on watch followed by a break of at least 1 hour; Maximum of 12 hours on watch per 24-hour period.

Minimum of 2 NMFS-approved PSOs on duty during 

daylight hours (30 minutes before sunrise through 30 

minutes after sunset); Limit of 2 consecutive hours 

on watch followed by a break of at least 1 hour; Maximum of 12 hours on watch per 24-hour period. 

Passive acoustic monitoring Not Required ................................................................... Not required. 

Exclusion zones ................... • 500 m (all marine mammals) ...................................... • 100 m (all marine mammals). 

• 1,500 m (Bowhead whales) ......................................... • 500 m (Bowhead whales). 

Pre-start clearance ............... Required; 30-minute clearance period of the following 

zones: 

Required; 30-minute clearance period of the following 

zones: 

• 1,000 m (all marine mammals) ................................... • 200 m (all marine mammals). 

• 1,500 m (Bowhead whales) ......................................... • 500 m (Bowhead whales). 

Following detection within zone, animal must be observed exiting or additional period of 15 or 30 minutes.Following detection within zone, animal must be observed exiting or additional period of 15 or 30 minutes. 

Ramp-up .............................. Required; duration ≥20 minutes ...................................... Required; duration not more than 20 minutes. 

Shutdown ............................. Shutdown required for marine mammal detected within 

defined EZs; Re-start allowed following clearance period of 15 or 30 minutes.

Shutdown required for marine mammal detected within 

defined EZs; Re-start allowed following clearance period of 15 or 30 minutes 

Vessel Strike Avoidance 

1. Vessel operators and crews must 

maintain a vigilant watch for all 

protected species and slow down, stop 

their vessel, or alter course, as 

appropriate and regardless of vessel 

size, to avoid striking any protected 

species. 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 

28804 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

duties must be provided sufficient 

training to 1) distinguish marine 

mammals from other phenomena, and 2) 

broadly identify a marine mammal as a 

bowhead whale, other whale (defined in 

this context as baleen whales other than 

bowhead whales), or other marine 

mammal. 

2. Vessel speeds must also be reduced 

to 10 knots or less when mother/calf 

pairs, pods, or large assemblages of 

cetaceans are observed near a vessel. 

3. All vessels must maintain a 

minimum separation distance of 500 m 

from bowhead whales. If a whale is 

observed but cannot be confirmed as a 

species other than a bowhead whale, the 

vessel operator must assume that it is a 

bowhead whale and take appropriate 

action. 

4. All vessels must maintain a 

minimum separation distance of 100 m 

from all other baleen whales. 

5. All vessels must, to the maximum 

extent practicable, attempt to maintain a 

minimum separation distance of 50 m 

from all other marine mammals, with an 

understanding that at times this may not 

be possible (e.g., for animals that 

approach the vessel). 

6. When marine mammals are sighted 

while a vessel is underway, the vessel 

shall take action as necessary to avoid 

violating the relevant separation 

distance (e.g., attempt to remain parallel 

to the animal’s course, avoid excessive 

speed or abrupt changes in direction 

until the animal has left the area). If 

protected species 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. 

7. These requirements do not apply in 

any case where compliance would 

create an imminent and serious threat to 

a person or vessel or to the extent that 

a vessel is restricted in its ability to 

maneuver and, because of the 

restriction, cannot comply. 

We did not identify any mitigation 

specifically appropriate for habitat. 

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 area; 

therefore, marine mammals that may be 

temporarily displaced during survey 

activities are expected to be able to 

resume foraging once they have moved 

away from areas with disturbing levels 

of underwater noise. The specified 

activity is if relatively short duration (30 

days) and the disturbance will be 

temporary in nature, similar habitat and 

resources are available 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. No BIAs, designated 

critical habitat, or other habitat of 

known significance would be impacted 

by the planned activities. 

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 proposed measures, as 

well as other measures considered by 

NMFS described above, NMFS has 

preliminarily 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, and on the 

availability of such species or stock for 

subsistence uses (see Unmitigable 

Adverse Impact Analysis and 

Determination). 

Proposed 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 proposed action area. 

Effective reporting is critical both to 

compliance as well as ensuring that the 

most value is obtained from the required 

monitoring. 

Monitoring and reporting 

requirements prescribed by NMFS 

should contribute to improved 

understanding of one or more of the 

following: 

• 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 

would take place during daytime airgun 

operations. During seismic operations, 

at least five visual PSOs would be based 

aboard the R/V Sikuliaq. Two visual 

PSOs would be on duty at all time 

during daytime hours. Monitoring shall 

be conducted in accordance with the 

following requirements: 

• The operator shall provide PSOs 

with bigeye binoculars (e.g., 25 x 150; 

2.7 view angle; individual ocular focus; 

height control) of appropriate quality 

(i.e., Fujinon or equivalent) solely for 

PSO use. These shall be 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 will work with the 

selected third-party observer provider to 

ensure PSOs have all equipment 

(including backup equipment) needed 

to adequately perform necessary tasks, 

including accurate determination of 

distance and bearing to observed marine 

mammals. 

PSOs must have the following 

requirements and qualifications: 

• PSOs shall be independent, 

dedicated, trained visual and acoustic 

PSOs and must be employed by a thirdparty observer provider; 

• PSOs shall have no tasks other than 

to conduct observational effort, collect 

data, and communicate with and 

instruct relevant vessel crew with regard 

to the presence of protected species and 

mitigation requirements (including brief 

alerts regarding maritime hazards); 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28805 

• PSOs shall have successfully 

completed an approved PSO training 

course; 

• NMFS must review and approve 

PSO resumes accompanied by a relevant 

training course information packet that 

includes the name and qualifications 

(i.e., experience, training completed, or 

educational background) of the 

instructor(s), the course outline or 

syllabus, and course reference material 

as well as a document stating successful 

completion of the course; 

• NMFS shall have one week to 

approve PSOs from the time that the 

necessary information is submitted, 

after which PSOs meeting the minimum 

requirements shall automatically be 

considered approved; 

• PSOs must successfully complete 

relevant training, including completion 

of all required coursework and passing 

(80 percent or greater) a written and/or 

oral examination developed for the 

training program; 

• PSOs must have successfully 

attained a bachelor’s degree from an 

accredited college or university with a 

major in one of the natural sciences, a 

minimum of 30 semester hours or 

equivalent in the biological sciences, 

and at least one undergraduate course in 

math or statistics; and 

• The educational requirements may 

be waived if the PSO has acquired the 

relevant skills through alternate 

experience. Requests for such a waiver 

shall be submitted to NMFS and must 

include written justification. Requests 

shall be granted or denied (with 

justification) by NMFS within one week 

of receipt of submitted information. 

Alternate experience that may be 

considered includes, but is not limited 

to (1) secondary education and/or 

experience comparable to PSO duties; 

(2) previous work experience 

conducting academic, commercial, or 

government-sponsored protected 

species surveys; or (3) previous work 

experience as a PSO; the PSO should 

demonstrate good standing and 

consistently good performance of PSO 

duties. Traditional ecological 

knowledge is also a relevant 

consideration. 

For data collection purposes, PSOs 

shall use standardized data collection 

forms, whether hard copy or electronic. 

PSOs shall record detailed information 

about any implementation of mitigation 

requirements, including the distance of 

animals to the acoustic source and 

description of specific actions that 

ensued, the behavior of the animal(s), 

any observed changes in behavior before 

and after implementation of mitigation, 

and if shutdown was implemented, the 

length of time before any subsequent 

ramp-up of the acoustic source. If 

required mitigation was not 

implemented, PSOs should record a 

description of the circumstances. At a 

minimum, the following information 

must be recorded: 

• 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-clearance, rampup, shutdown, testing, shooting, rampup completion, end of operations, 

streamers, etc.). 

The following information should 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. 

Reporting 

A report would be submitted to NMFS 

within 90 days after the end of the 

cruise. The report would describe the 

operations that were conducted and 

sightings of marine mammals near the 

operations. The report would provide 

full documentation of methods, results, 

and interpretation pertaining to all 

monitoring. The 90-day report would 

summarize the dates and locations of 

seismic operations, and all marine 

mammal sightings (dates, times, 

locations, activities, associated seismic 

survey activities). 

The draft report shall also include 

geo-referenced time-stamped vessel 

tracklines for all time periods during 

which airguns were operating. 

Tracklines should include points 

recording any change in airgun status 

(e.g., when the airguns began operating, 

when they were turned off, or when 

they changed from full array to single 

gun or vice versa). GIS files shall be 

provided in ESRI shapefile format and 

include the UTC date and time, latitude 

in decimal degrees, and longitude in 

decimal degrees. All coordinates shall 

be referenced to the WGS84 geographic 

coordinate system. In addition to the 

report, all raw observational data shall 

be made available to NMFS. The report 

must summarize the data collected as 

described above and in the IHA. A final 

report must be submitted within 30 days 

following resolution of any comments 

on the draft report. 

28806 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

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 UAGI shall 

report the incident to the Office of 

Protected Resources (OPR), NMFS and 

to the NMFS Alaska Regional Stranding 

Coordinator as soon as feasible. The 

report must include the following 

information: 

• 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, UAGI shall report the 

incident to OPR, NMFS and to the 

NMFS Alaska Regional Stranding 

Coordinator as soon as feasible. The 

report must include the following 

information: 

• 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). 

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, 

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. 

NMFS does not anticipate that injury, 

serious injury or mortality would occur 

as a result of UAGI’s planned survey, 

even in the absence of mitigation, and 

none would be authorized. Similarly, 

non-auditory physical effects, stranding, 

and vessel strike are not expected to 

occur. Although a few incidents of Level 

A harassment were predicted through 

the quantitative exposure estimation 

process (see Estimated Take), NMFS has 

determined that this is not a realistic 

result due to the small estimated Level 

A harassment zones for the species (no 

greater than approximately 50 m) and 

the proposed mitigation requirements, 

and no Level A harassment is proposed 

for authorization. These estimated zones 

are larger than what would realistically 

occur, as discussed in the Estimated 

Take section. Although no Level A 

harassment would be expected to occur 

even absent mitigation, the extended 

distance exclusion zones proposed for 

bowhead whales further strengthen this 

conclusion. 

We expect that 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 

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). The 

proposed number of takes for bowhead 

whales is 2 percent of the population. 

We expect this number to be even 

smaller as the likelihood of 

encountering these animals in deep 

waters in the Northern Arctic Ocean are 

slim based on recent telemetry data 

(Quakenbush, Small & Citta, 2013). 

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 area; 

therefore, marine mammals that may be 

temporarily displaced during survey 

activities are expected to be able to 

resume foraging once they have moved 

away from areas with disturbing levels 

of underwater noise. Because of the 

relatively short duration (30 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 longterm consequences for individual 

marine mammals or their populations. 

No BIAs, designated critical habitat, or 

other habitat of known significance 

would be impacted by the planned 

activities. 

Negligible Impact Conclusions 

The proposed survey would be of 

short duration (30 days of seismic 

operations), and the acoustic ‘‘footprint’’ 

of the proposed survey would be small 

relative to the ranges of the marine 

mammals that would potentially be 

affected. Sound levels would increase in 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28807 

the marine environment in a relatively 

small area surrounding the vessel 

compared to the range of the marine 

mammals within the proposed survey 

area. Short term exposures to survey 

operations are expected to only 

temporarily affect marine mammal 

behavior in the form of avoidance, and 

the potential for longer-term avoidance 

of important areas is limited. Short term 

exposures to survey operations are not 

likely to impact marine mammal 

behavior, and the potential for longerterm avoidance of important areas is 

limited. 

The proposed mitigation measures are 

expected to reduce the number and/or 

severity of takes by allowing for 

detection of marine mammals in the 

vicinity of the vessel by visual 

observers, and by minimizing the 

severity of any potential exposures via 

shutdowns of the airgun array. 

NMFS concludes that exposures to 

marine mammal species and stocks due 

to UAGI’s proposed survey would result 

in only short-term (temporary and short 

in duration) effects to individuals 

exposed, over relatively small areas of 

the affected animals’ ranges. Animals 

may temporarily avoid the immediate 

area, but are not expected to 

permanently abandon the area. Major 

shifts in habitat use, distribution, or 

foraging success are not expected. 

NMFS does not anticipate the proposed 

take estimates to impact annual rates of 

recruitment or survival. 

In summary and as described above, 

the following factors primarily support 

our preliminary 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 Level A harassment, serious 

injury or mortality is anticipated or 

proposed to be authorized; 

• The proposed activity is temporary 

and of relatively short duration (30 

days); 

• The anticipated impacts of the 

proposed activity on marine mammals 

would primarily be temporary 

behavioral changes in the form of 

avoidance of the area around the survey 

vessel; 

• Location of the survey is further 

north in the Arctic Ocean and away 

from areas where most of the species 

listed in Table 1 have been observed 

and is north of summer feeding areas 

and migratory routes. 

• The availability of alternate areas of 

similar habitat value for marine 

mammals to temporarily vacate the 

survey area during the proposed 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 

proposed survey would be temporary 

and spatially limited, and impacts to 

marine mammal foraging would be 

minimal; and 

• The proposed mitigation measures, 

including visual monitoring, 

shutdowns, ramp-up, and prescribed 

measures based on energy size 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 

proposed monitoring and mitigation 

measures, NMFS preliminarily finds 

that the total marine mammal take from 

the proposed activity will have a 

negligible impact on all affected marine 

mammal species or stocks. 

Small Numbers 

As noted above, only small numbers 

of incidental take may be authorized 

under sections 101(a)(5)(A) and (D) of 

the MMPA for specified activities other 

than military readiness activities. The 

MMPA does not define small numbers 

and so, in practice, where estimated 

numbers are available, NMFS compares 

the number of individuals taken to the 

most appropriate estimation of 

abundance of the relevant species or 

stock in our determination of whether 

the take 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 (see 86 Federal 

Register 5322, 5439 (January 19, 2021). 

Additionally, other qualitative factors 

may be considered in the analysis, such 

as the temporal or spatial scale of the 

activities. 

There are several stocks for which 

there is no currently accepted stock 

abundance estimate. These include the 

fin whale, minke whale, narwhal, 

bearded seal, and ringed seal. In those 

cases, qualitative factors are used to 

inform an assessment of whether the 

likely number of individual marine 

mammals taken is appropriately 

considered small. We discuss these in 

further detail below. 

For all other stocks (aside from those 

without accepted abundance estimates), 

the proposed take is less than 7% of the 

best available stock abundance, well 

less than the one-third threshold for 

exceeding small numbers (and some of 

those takes may be repeats of the same 

individual, thus rendering the actual 

percentage even lower). We also 

acknowledge that, given the location of 

the planned survey activity high in the 

Arctic Ocean, the stock ranges 

referenced in the SARs do not always 

fully overlap the area of the planned 

survey activity. However, given the very 

small percentage of the best available 

stock abundance estimates for these 

species and the likelihood that the 

numbers of take proposed for 

authorization would be very small 

relative to any reasonable population 

abundance estimate, we conclude these 

numbers are small. 

The stock abundance estimates for fin 

whale, minke whale, narwhal, bearded 

seal and ringed seal stocks that occur in 

the surveys area are unknown, 

according to the latest SARs. Therefore, 

we reviewed other scientific 

information in making our small 

numbers determinations for these 

animals. The abundance estimate of 

20,000 minke whales was taken from 

the Northwest Pacific and Okhotsk Sea 

(IWC 2021). In addition, as noted 

previously, partial abundance estimates 

of 1,233 and 2,020 minke whales are 

available for shelf and nearshore waters 

between the Kenai Peninsula and 

Amchitka Pass and for the eastern 

Bering Sea shelf, respectively. For the 

minke whale, these partial abundance 

estimates alone are sufficient to 

demonstrate that the proposed take 

number of 2 is of small numbers. The 

same surveys produced partial 

abundance estimates of 1,652 and 1,061 

fin whales, for the same areas, 

respectively, which are similarly 

sufficient to demonstrate that the 

proposed take number of 2 is small 

numbers. The bearded seal estimate of 

125,000 was estimated for the U.S. 

portion of the Bering Sea (Boveng et al., 

2017) and 155,000 bearded seals for the 

entire Alaska stock (Cameron et al., 

2010). These partial abundance 

estimates near the proposed survey are 

sufficient to demonstrate that the 

proposed take number of 916 seals is 

small numbers. Similarly, the ringed 

seal abundance estimate of 171,418 

ringed seals was based on a limited subsample from the Bering Sea (Conn et al., 

2014 in Muto et al., 2020). This minimal 

abundance estimate for the Alaska 

region is enough to demonstrate that a 

take of 10,373 will be small numbers at 

6.05% of the Bering Sea population. 

There is no abundance information 

available for narwhals. However, the 

take number is sufficiently small (2) that 

we assume that it is small relative to any 

reasonable assumption of likely 

population abundance for the narwhal. 

Additionally, the proposed survey area 

28808 Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 

encompasses a very small portion of the 

hypothesized range of the species. 

Based on the analysis contained 

herein of the proposed activity 

(including the proposed mitigation and 

monitoring measures) and the 

anticipated take of marine mammals, 

NMFS preliminarily 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 

In order to issue an IHA, NMFS must 

find that the specified activity will not 

have an ‘‘unmitigable adverse impact’’ 

on the subsistence uses of the affected 

marine mammal species or stocks by 

Alaskan Natives. NMFS has defined 

‘‘unmitigable adverse impact’’ in 50 CFR 

216.103 as an impact resulting from the 

specified activity: (1) That is likely to 

reduce the availability of the species to 

a level insufficient for a harvest to meet 

subsistence needs by: (i) Causing the 

marine mammals to abandon or avoid 

hunting areas; (ii) Directly displacing 

subsistence users; or (iii) Placing 

physical barriers between the marine 

mammals and the subsistence hunters; 

and (2) That cannot be sufficiently 

mitigated by other measures to increase 

the availability of marine mammals to 

allow subsistence needs to be met. 

The coast and nearshore waters of 

Alaska are of cultural importance to 

indigenous peoples for fishing, hunting, 

gathering, and ceremonial purposes. 

Marine mammals are legally hunted in 

Alaskan waters by coastal Alaska 

Natives. There are seven communities 

in the North Slope Borough region of 

Alaska (northwestern and northern 

Alaska) that harvest seals, including 

from west to east Point Hope, Point Lay, 

Wainwright, Utqiag ̇vik, Atqusak, 

Nuiqsut, and Kaktovik (Ice Seal 

Committee 2019). Bearded seals are the 

preferred species to harvest as food and 

for skin boat coverings, but ringed seals 

are also commonly taken for food and 

their blubber (Ice Seal Committee 2019). 

Ringed seals are typically harvested 

during the summer and can extend up 

to 64 km from shore (Stephen R. Braund 

& Associates 2010). No ribbon seals 

have been harvested in any of the North 

Slope Borough communities since the 

1960s (Ice Seal Committee 2019). 

However, the number of seals harvested 

each year varies considerably. 

A subsistence harvest of bowheads 

and belugas is also practiced by Alaskan 

Natives, providing nutritional and 

cultural needs. In 2019, 36 bowhead 

whales were taken during the Alaskan 

subsistence hunt (Suydam et al., 2020). 

Whaling near Utqiag ̇vik occurs during 

spring (April and May) and autumn, and 

can continue into November, depending 

on the quota and conditions. 

Communities that harvested bowheads 

during 2019 include Utqiag ̇vik, Gamgell, 

Kaktovik, Nuiqsut, Point Hope, Point 

Lay, and Wainwright. Bowhead whales 

and gray whales are also taken in the 

aboriginal subsistence hunt in the 

Russian Federation (Zharikov et al., 

2020). During 2019, 135 gray whales 

and one bowhead whale were harvested 

at Chukotka. 

Beluga whales from the eastern 

Chukchi Sea stock are an important 

subsistence resource for residents of the 

village of Point Lay, adjacent to 

Kasegaluk Lagoon, and other villages in 

northwest Alaska. Each year, hunters 

from Point Lay drive belugas into the 

lagoon to a traditional hunting location. 

The belugas have been predictably 

sighted near the lagoon from late June 

through mid to late July (Suydam et al., 

2001). The mean annual number of 

Beaufort Sea belugas landed by Alaska 

Native subsistence hunters in 2011– 

2015 was 47, and an average of 92 were 

taken in Canadian waters; the mean 

annual number of Eastern Chukchi Sea 

belugas landed by Alaska Native 

subsistence hunters in 2011–2015 was 

67 (Muto et al., 2020). 

The proposed survey by UAGI will 

occur within ∼73.5–81.0 °N, ∼139.5–168 

°W and over 300 km from the Alaska 

coastline. Due to the location of the 

survey being far north in the Arctic and 

over 200 kilometers from any hunting 

area or buffer (http://www.northslope.org/assets/images/uploads/ 

bowhead%20migration

%20map%2021mar03

%20distribution.pdf), no impacts on the 

availability of marine mammals for 

subsistence uses are expected to occur. 

Specifically, based on the survey 

methods and location proposed, there is 

no reason to believe that there will be 

any behavioral disturbance of bowhead 

whales that would also impact their 

behavior in a manner that would 

interfere with subsistence use later. 

Although fishing/hunting would not be 

precluded in the survey area, a safe 

distance would need to be kept from 

R/V Sikuliaq and the towed seismic 

equipment. The principal investigator 

for the survey has presented the 

proposed action to the Alaska Eskimo 

Whaling Commission (AEWC) at the 

July 2020, October 2020, and February 

2021 Triannual Meetings. As 

specifically noted, during the meetings, 

daily email communications with 

interested community members would 

be made from the vessel. 

Communication may include notice of 

any unusual marine mammal 

observations during the survey. Any 

potential space use conflicts would be 

further avoided through direct 

communication with subsistence 

fishers/hunters during the surveys. 

Considering the limited time that the 

planned seismic surveys would take 

place and the far offshore location of the 

surveys, no direct interaction with 

subsistence fishers/hunters would be 

anticipated. However, UAGI will still be 

required to remain in constant 

communication with subsistence 

fishers/hunters during the surveys. 

Based on the description of the 

specified activity, the measures 

described to minimize adverse effects 

on the availability of marine mammals 

for subsistence purposes, and the 

proposed mitigation and monitoring 

measures, NMFS has preliminarily 

determined that there will not be an 

unmitigable adverse impact on 

subsistence uses from UAGI’s proposed 

activities. 

Endangered Species Act 

Section 7(a)(2) of the Endangered 

Species Act of 1973 (ESA: 16 U.S.C. 

1531 et seq.) requires that each Federal 

agency insure that any action it 

authorizes, funds, or carries out is not 

likely to jeopardize the continued 

existence of any endangered or 

threatened species or result in the 

destruction or adverse modification of 

designated critical habitat. To ensure 

ESA compliance for the issuance of 

IHAs, NMFS consults internally 

whenever we propose to authorize take 

for endangered or threatened species. 

NMFS is proposing to authorize take 

of bowhead whales, fin whales, bearded 

seals and ringed seals, which are listed 

under the ESA. 

OPR Permits and Conservation 

Division has requested initiation of 

Section 7 consultation with the OPR 

Endangered Species Act Interagency 

Cooperation Division for the issuance of 

this IHA. NMFS will conclude the ESA 

consultation prior to reaching a 

determination regarding the proposed 

issuance of the authorization. 

Proposed Authorization 

As a result of these preliminary 

determinations, NMFS proposes to issue 

an IHA to UAGI for conducting 

geophysical surveys in the Arctic in 

August and September, 2021, provided 

the previously mentioned mitigation, 

monitoring, and reporting requirements 

are incorporated. A draft of the 

proposed IHA can be found at https:// 

www.fisheries.noaa.gov/permit/ 

incidental-take-authorizations-undermarine-mammal-protection-act. 

Federal Register / Vol. 86, No. 102 / Friday, May 28, 2021 / Notices 28809 

Request for Public Comments 

We request comment on our analyses, 

the proposed authorization, and any 

other aspect of this notice of proposed 

IHA for the proposed geophysical 

surveys. We also request at this time 

comment on the potential Renewal of 

this proposed IHA as described in the 

paragraph below. Please include with 

your comments any supporting data or 

literature citations to help inform 

decisions on the request for this IHA or 

a subsequent renewal IHA. 

On a case-by-case basis, NMFS may 

issue a one-time, one-year 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, or nearly 

identical, activities as described in the 

Description of Proposed Activity section 

of this notice is planned or (2) the 

activities as described in the Description 

of Proposed Activity section of this 

notice 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 and Duration section of this 

notice, provided all of the following 

conditions are met: 

• A request for renewal is received no 

later than 60 days prior to the needed 

renewal IHA effective date (recognizing 

that the renewal IHA expiration date 

cannot extend beyond one year from 

expiration of the initial IHA). 

• The request for renewal must 

include the following: 

(1) An explanation that the activities 

to be conducted under the requested 

renewal IHA are identical to the 

activities analyzed under the initial 

IHA, are a subset of the activities, or 

include changes so minor (e.g., 

reduction in pile size) that the changes 

do not affect the previous analyses, 

mitigation and monitoring 

requirements, or take estimates (with 

the exception of reducing the type or 

amount of take). 

(2) A preliminary monitoring report 

showing the results of the required 

monitoring to date and an explanation 

showing that the monitoring results do 

not indicate impacts of a scale or nature 

not previously analyzed or authorized. 

Upon review of the request for 

renewal, the status of the affected 

species or stocks, and any other 

pertinent information, NMFS 

determines that there are no more than 

minor changes in the activities, the 

mitigation and monitoring measures 

will remain the same and appropriate, 

and the findings in the initial IHA 

remain valid. 

Dated: May 25, 2021. 

Catherine Marzin, 

Acting Director, Office of Protected Resources, 

National Marine Fisheries Service. 

[FR Doc. 2021–11339 Filed 5–27–21; 8:45 am] 

BILLING CODE 3510–22–P 

COMMITTEE FOR PURCHASE FROM 

PEOPLE WHO ARE BLIND OR 

SEVERELY DISABLED 

Procurement List; Proposed Additions 

and Deletions 

AGENCY: Committee for Purchase From 

People Who Are Blind or Severely 

Disabled. 

ACTION: Proposed additions to and 

deletions from the Procurement List. 

SUMMARY: The Committee is proposing 

to add product(s) and service(s) to the 

Procurement List that will be furnished 

by nonprofit agencies employing 

persons who are blind or have other 

severe disabilities, and delete products 

previously furnished by such agencies. 

DATES: Comments must be received on 

or before: June 27, 2021. 

ADDRESSES: Committee for Purchase 

From People Who Are Blind or Severely 

Disabled, 1401 S Clark Street, Suite 715, 

Arlington, Virginia 22202–4149. 

FOR FURTHER INFORMATION CONTACT: For 

further information or to submit 

comments contact: Michael R. 

Jurkowski, Telephone: (703) 785–6404, 

or email CMTEFedReg@AbilityOne.gov. 

SUPPLEMENTARY INFORMATION: This 

notice is published pursuant to 41 

U.S.C. 8503 (a)(2) and 41 CFR 51–2.3. Its 

purpose is to provide interested persons 

an opportunity to submit comments on 

the proposed actions. 

Additions 

If the Committee approves the 

proposed additions, the entities of the 

Federal Government identified in this 

notice will be required to procure the 

product(s) and service(s) listed below 

from nonprofit agencies employing 

persons who are blind or have other 

severe disabilities. 

The following product(s) and 

service(s) are proposed for addition to 

the Procurement List for production by 

the nonprofit agencies listed: 

Product(s) 

NSN(s)—Product Name(s): 

6540–00–NIB–0079—Lens Cleaning 

Station, Disposable, 16 Oz. Spray Bottle 

Cleaner 

6540–00–NIB–0080—Lens Cleaning 

Station, Disposable, 8 Oz. Spray Bottle 

Cleaner 

Designated Source of Supply: Chicago 

Lighthouse Industries, Chicago, IL 

Mandatory For: Total Government 

Requirement 

Contracting Activity: DEFENSE LOGISTICS 

AGENCY, DLA TROOP SUPPORT 

Distribution: A-List 

Service(s) 

Service Type: Facility Management 

Mandatory for: US Air Force, Airmen-InTraining Dormitories, Sheppard Air 

Force Base, TX 

Designated Source of Supply: Work Services 

Corporation, Wichita Falls, TX 

Contracting Activity: DEPT OF THE AIR 

FORCE, FA3020 82 CONS LGC 

Deletions 

The following product(s) are proposed 

for deletion from the Procurement List: 

Product(s) 

NSN(s)—Product Name(s): 8010–01–363– 

3375—Enamel, Aerosol, Type I, Flat 

Gray—36081, Pint, BX/12 

Designated Source of Supply: The Lighthouse 

for the Blind, St. Louis, MO 

Contracting Activity: DLA TROOP SUPPORT, 

PHILADELPHIA, PA 

Michael R. Jurkowski, 

Deputy Director, Business Operations. 

[FR Doc. 2021–11309 Filed 5–27–21; 8:45 am] 

BILLING CODE 6353–01–P 

COMMITTEE FOR PURCHASE FROM 

PEOPLE WHO ARE BLIND OR 

SEVERELY DISABLED 

Procurement List; Additions and 

Deletions 

AGENCY: Committee for Purchase From 

People Who Are Blind or Severely 

Disabled. 

ACTION: Additions to and deletions from 

the Procurement List. 

SUMMARY: This action deletes products 

from the Procurement List previously 

furnished by nonprofit agencies 

employing persons who are blind or 

have other severe disabilities. 

DATES: Date added to and deleted from 

the Procurement List: June 27, 2021. 

ADDRESSES: Committee for Purchase 

From People Who Are Blind or Severely 

Disabled, 1401 S Clark Street, Suite 715, 

Arlington, Virginia, 22202–4149. 

FOR FURTHER INFORMATION CONTACT: 

Michael R. Jurkowski, Telephone: (703) 

785–6404, or email CMTEFedReg@

AbilityOne.gov. 

SUPPLEMENTARY INFORMATION: 

Deletions 

On 4/23/2021, the Committee for 

Purchase From People Who Are Blind 

or Severely Disabled published notice of 

proposed deletions from the 

Procurement List. This notice is