Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Geophysical Survey in the Ross Sea, Antarctica, 77796-77812 [2022-27498]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 87, Number 243 (Tuesday, December 20, 2022)]
[Notices]
[Pages 77796-77812]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-27498]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC454]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Geophysical Survey in the Ross 
Sea, Antarctica

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

ACTION: Notice; Issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an Incidental Harassment Authorization (IHA) to 
the U.S. National Science Foundation (NSF) to incidentally harass 
marine mammals during geophysical surveys in the Ross Sea, Antarctica.

DATES: This authorization is effective from December 15, 2022 through 
December 14, 2023.

FOR FURTHER INFORMATION CONTACT: Jenna Harlacher, 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/action/incidental-take-authorization-national-science-foundation-office-polar-programs-geophysical. In case of 
problems accessing these documents, please call the contact listed 
above.

SUPPLEMENTARY INFORMATION: 

[[Page 77797]]

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

Summary of Request

    On May 26, 2022, NMFS received a request from NSF for an IHA to 
take marine mammals incidental to conducting a low energy seismic 
survey and icebreaking in the Ross Sea. The application was deemed 
adequate and complete on July 22, 2022. NSF's request is for take of 
small numbers of 17 species of marine mammals by Level B harassment 
only. Neither NSF nor NMFS expects serious injury or mortality to 
result from this activity and, therefore, an IHA is appropriate. The 
proposed IHA was published on September 29, 2022 (87 FR 59204). There 
are no changes from the proposed IHA to the final IHA.

Description of Activity

Overview

    Researchers from Louisiana State University, Texas A&M University, 
University of Texas at Austin, University of West Florida, and Dauphin 
Island Sea Lab, with funding from NSF, plan to conduct a two-part low-
energy seismic survey from the Research Vessel/Icebreaker (RVIB) 
Nathaniel B. Palmer (NBP), in the Ross Sea during Austral Summer 2022-
2023. The two-part survey would include the Ross Bank and the Drygalski 
Trough areas. The planned seismic survey would take place in 
International waters of the Southern Ocean, in water depths ranging 
from approximately (~) 150 to 1100 meters (m).
    The RVIB Palmer would deploy up to two 105-cubic inch (in\3\) 
generator injector (GI) airguns at a depth of 1-4 m with a total 
maximum discharge volume for the largest, 2-airgun array of 210 in\3\ 
along predetermined track lines. During the Ross Bank survey, ~1920 km 
of seismic data would be collected and during the Drygalski Trough 
survey, ~1800 km of seismic acquisition would occur, for a total of 
3720 line km.
    Although the survey will occur in the Austral summer, some 
icebreaking activities are expected to be required during the cruise.
    The Ross Bank portion of activity is to determine if, how, when, 
and why the Ross Ice Shelf unpinned from Ross Bank in the recent 
geologic past, to assess to what degree that event caused a re-
organization of ice sheet and ice shelf flow towards its current 
configuration. The Drygalski Trough activities plan to examine the gas 
hydrate contribution to the Ross Sea carbon budget. The Drygalski 
Trough activities would examine the warming and carbon cycling of the 
ephemeral reservoir of carbon at the extensive bottom ocean layer-
sediment interface of the Ross Sea. This large carbon reserve appears 
to be sealed in the form of gas hydrate and is a thermogenic carbon 
source and carbon storage in deep sediment hydrates. The warming and 
ice melting coupled with high thermogenic gas hydrate loadings suggest 
the Ross Sea is an essential environment to determine contributions of 
current day and potential future methane, petroleum, and glacial carbon 
to shallow sediment and water column carbon cycles.

Dates and Duration

    The RVIB Palmer would likely depart from Lyttelton, New Zealand, on 
December 18, 2022, and would return to McMurdo Station, Antarctica, on 
January 18, 2023, after the program is completed. The cruise is 
expected to consist of 31 days at sea, including approximately 19 days 
of seismic operations (including 2 days of sea trials and/or 
contingency), 1 day of ocean bottom seismometer (OBS) deployment/
recovery, and approximately 11 days of transit. Some deviation in 
timing and ports of call could also result from unforeseen events such 
as weather or logistical issues.

Specific Geographic Region

    The survey would take place in the Ross Sea, Antarctica 
(continental shelf between ~75[deg]-77.7[deg]S and 1 71[deg]E-173[deg] 
E and Drygalski Trough between ~74[deg]76.7[deg] S and 163.6[deg]E-
170[deg] E (Figure 1) in international waters of the Southern Ocean in 
water depths ranging from approximately 150 to 1100 m. Representative 
survey tracklines are shown in Figure 1; however, the actual survey 
effort could occur anywhere within the outlined study area as shown. 
The line locations for the survey area are preliminary and could be 
refined in light of information from data collected during the study 
and conditions within the survey area.

[[Page 77798]]

[GRAPHIC] [TIFF OMITTED] TN20DE22.004

Detailed Description of Specific Activity

    The procedures to be used for the survey would entail use of 
conventional seismic methodology. The survey would involve one source 
vessel, RVIB Palmer and the airgun array would be deployed at a depth 
of approximately 1-4 m below the surface, spaced approximately 2.4 m 
apart for the 2-gun array. Seismic acquisition is planned to begin with 
a standard sea trial to determine which configuration and mode of GI 
airgun(s) provide the best reflection signals, which depends on sea-
state and subsurface conditions. A maximum of two GI airguns would be 
used. Four GI configurations (each using one or two GI airguns) would 
be tested during the sea trial (Table 1). The largest volume airgun 
configuration (configuration 4) was carried forward in our analysis and 
used for estimating the take numbers for authorization.
    The RVIB Palmer would deploy two 105 in\3\ GI airguns as an energy 
source with a total volume of ~210 in\3\. Seismic pulses would be 
emitted at intervals of 5 to 10 seconds from the GI airgun. The 
receiving system would consist of one hydrophone streamer, 800 m in 
length, with the vessel traveling at 8.3 km/hr (4.5 knots (kn)) to 
achieve high-quality seismic reflection data. As the airguns are towed 
along the survey lines, the hydrophone streamer would receive the 
returning acoustic signals and transfer the data to the on-board 
processing system. If sea-ice conditions permit, a multi-channel 
digital streamer would be used to improve signal-to-noise ratio by 
digital data processing; if ice is present, a single-channel digital 
steamer would be employed. When not towing seismic survey gear, the 
RVIB Palmer has a maximum speed of 26.9 km/h (14.5 kn), but cruises at 
an average speed of 18.7 km/h (10.1 kn). During the Ross Bank survey, 
~1920 km of seismic data would be collected and during the Drygalski 
Trough survey, ~1800 km of seismic acquisition would occur, for a total 
of 3720 line km.
    During the Drygalski Trough survey, 2 deployments of 10 OBSs would 
occur along 2 different seismic refraction lines (see Fig. 1 for 
representative lines). Following refraction shooting of one line, OBSs 
on that line would be recovered, serviced, and redeployed on a 
subsequent refraction line. The spacing of OBSs on the initial 
refraction line would be 5 km apart, but OBSs could be deployed as 
close together as every 500 m on the subsequent refraction line. All 
OBSs would be recovered at the end of the survey. To retrieve the OBSs, 
the instrument is released via an acoustic release system to float to 
the surface from the wire and/or anchor, which are not retrieved.

[[Page 77799]]



     Table 1--Four GI Configurations (Each Using One or Two GI Airguns) Would be Tested During the Sea Trial
----------------------------------------------------------------------------------------------------------------
                                Airgun array Total Volume      Frequency between
        Configuration              (GI configuration)            seismic shots             Streamer length
----------------------------------------------------------------------------------------------------------------
1...........................  50 in\3\ Harmonic Mode        5-10 seconds...........  800 m.
                               configured as 25 in\3\
                               Generator + 25 Injector
                               in\3\.
2...........................  90 in\3\ Harmonic Mode        5-10 seconds...........  ...........................
                               configured as 45 in\3\
                               Generator + 45 Injector
                               in\3\.
3...........................  50 in\3\ True-GI Mode         5-10 seconds...........  ...........................
                               configured as 45 in\3\
                               Generator + 105 Injector
                               in3.
4...........................  210 in\3\ Harmonic Mode       5-10 seconds...........  ...........................
                               configured as 105 in\3\
                               Generator + 105 Injector
                               in\3\.
----------------------------------------------------------------------------------------------------------------

    There could be additional seismic operations in the study area 
associated with equipment testing, re-acquisition due to reasons such 
as, but not limited to, equipment malfunction, data degradation during 
poor weather, or interruption due to shut down or track deviation in 
compliance with IHA requirements. To account for these additional 
seismic operations, 25 percent has been added in the form of 
operational days, which is equivalent to adding 25 percent to the line 
km to be surveyed.
    Along with the airgun and OBS operations, additional acoustical 
data acquisition systems and other equipment may be operated during the 
seismic survey at any time to meet scientific objectives. The ocean 
floor would be mapped with a Multibeam Ecosounder (MBES), Sub-bottom 
Profiler (SBP), and/or Acoustic Doppler Current Profiler (ADCP). Data 
acquisition in the survey area will occur in water depths ranging from 
150 to 700 m. Take of marine mammals is not expected to occur 
incidental to use of these other sources, whether or not the airguns 
are operating simultaneously with the other sources. Given their 
characteristics (e.g., narrow downward-directed beam), marine mammals 
would experience no more than one or two brief ping exposures, if any 
exposure were to occur. NMFS does not expect that the use of these 
sources presents any reasonable potential to cause take of marine 
mammals.
    (1) Single Beam Echo Sounder (Knudsen 3260)--The hull-mounted 
compressed high-intensity radiated pulse (CHIRP) sonar is operated at 
12 kilohertz (kHz) for bottom-tracking purposes or at 3.5 kHz in the 
sub-bottom profiling mode. The sonar emits energy in a 30[deg] beam 
from the bottom of the ship and has a sound level of 224 dB re: 1 
[mu]Pa m (rms).
    (2) Multibeam Sonar (Kongsberg EM122)--The hull-mounted, multibeam 
sonar operates at a frequency of 12 kHz, has an estimated maximum 
source energy level of 242 dB re 1[mu]Pa (rms), and emits a very narrow 
(< 2[deg]) beam fore to aft and 150[deg] in cross-track. The multibeam 
system emits a series of nine consecutive 15 millisecond (ms) pulses.
    (3) Acoustic Doppler Current Profiler (ADCP) (Teledyne RDI VM-
150)--The hull-mounted ADCP operates at a frequency of 150 kHz, with an 
estimated acoustic output level at the source of 223.6 dB re 1[mu]Pa 
(rms). Sound energy from the ADCP is emitted as a 30[deg], conically 
shaped beam.
    (4) ADCP (Ocean Surveyor OS-38)--The characteristics of this 
backup, hull-mounted ADCP unit are similar to the Teledyne VM-150. The 
ADCP operates at a frequency of 150 kHz with an estimated acoustic 
output level at the source of 223.6 dB re 1[mu]Pa (rms). Sound energy 
from the ADCP is emitted as a 30[deg] conically-shaped beam.
    (5) EK biological echo sounder (Simrad ES200-7C, ES38B, ES-120-
7C)--This echo sounder is a split-beam transducer with an estimated 
acoustic output level at the source of 183-185 dB re 1[mu]Pa and emits 
a 7[deg] beam. It can operate at 38 kHz, 120 kHz and 200 kHz.
    (6) Acoustic Release--To retrieve OBSs, an acoustic release 
transponder (pinger) is used to interrogate the instrument at a 
frequency of 8-11 kHz, and a response is received at a frequency of 7- 
15 kHz. The burn-wire release assembly is then activated, and the 
instrument is released to float to the surface from the wire and/or 
anchor which are not retrieved.
    (7) Oceanographic Sampling--during the Drygalski Trough study, the 
researchers would also conduct opportunistic oceanographic sampling as 
time and scheduling allows, including conductivity, temperature and 
depth (CTD) measurements, box cores, and/or multi-cores.
Icebreaking
    Icebreaking activities are expected to be limited during the 
survey. The Ross Sea is generally clear of ice January through 
February, because of the large Ross Sea Polynya that occurs in front of 
the Ross Ice Shelf. Heavy ice conditions would hamper the planned 
activities, as noise from icebreaking degrades the quality of the 
geophysical data to be acquired. If the RVIB Palmer would find itself 
in heavy ice conditions, it is unlikely that the airgun(s) and streamer 
could be towed, as this could damage the equipment and generate noise 
interference. The seismic survey could take place in low ice conditions 
if the RVIB Palmer were able to generate an open path behind the 
vessel. The RVIB Palmer is not rated for breaking multi-year ice and 
generally avoids transiting through ice two years or older and more 
than one m thick. If sea ice were to be encountered during the survey, 
the RVIB Palmer would likely proceed through one-year sea ice, and new, 
thin ice, but would follow leads wherever possible. Any time spent 
icebreaking would take away time from the planned research activities, 
as the vessel would travel slower in ice-covered seas. Based on 
estimated transit to the survey area, it is estimated that the RVIB 
Palmer would break ice up to a distance of 500 km. Based on a ship 
speed of 5 kn under moderate ice conditions, this distance represents 
approximately 54 hours of icebreaking (or 2.2 days). Transit through 
areas of primarily open water containing brash ice or pancake ice is 
not considered icebreaking for the purposes of this assessment.
    Mitigation, monitoring, and reporting measures are described in 
detail later in this document (please see Mitigation and Monitoring and 
Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to NSF was published in 
the Federal Register on September 29, 2022 (87 FR 59204). That notice 
described, in detail, NSF's activities, the marine mammal species that 
may be affected by the activities, and the anticipated effects on 
marine mammals. In that notice, we requested public input on the 
request for authorization described therein, our analyses, the proposed 
authorization,

[[Page 77800]]

and any other aspect of the notice of proposed IHA, and requested that 
interested persons submit relevant information, suggestions, and 
comments. This proposed notice was available for a 30-day public 
comment period.
    NMFS received no public comments.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more 
general information about these species (e.g., physical and behavioral 
descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    The populations of marine mammals considered in this document do 
not occur within the U.S. Exclusive Economic Zone (EEZ) and are 
therefore not assigned to stocks and are not assessed in NMFS' Stock 
Assessment Reports (SAR). As such, information on potential biological 
removal (PBR; 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) and on annual levels of serious injury and 
mortality from anthropogenic sources are not available for these marine 
mammal populations. Abundance estimates for marine mammals in the 
survey location are lacking; therefore estimates of abundance presented 
here are based on a variety of other sources including International 
Whaling Commission (IWC) population estimates, the International Union 
for Conservation of Nature's (IUCN) Red List of Threatened Species, and 
various literature estimates (see IHA application for further detail), 
as this is considered the best available information on potential 
abundance of marine mammals in the area.
    Seventeen species of marine mammals could occur in the Ross Sea, 
including 5 mysticetes (baleen whales), 7 odontocetes (toothed whales) 
and 5 pinniped species (Table 2). Another seven species occur in the 
Sub-Antarctic but are unlikely to be encountered in the survey areas, 
as they generally occur farther to the north than the project area. 
These species are not discussed further here but include: the southern 
right whale (Eubalaena australis), common (dwarf) minke whale 
(Balaenoptera acutorostrata), Cuvier's beaked (Ziphius cavirostris), 
Gray's beaked (Mesoplodon grayi), Hector's beaked (Mesoplodon hectori), 
and spade-toothed beaked (Mesoplodon traversii) whales, southern right 
whale dolphin (Lissodelphis peronii), and spectacled porpoise (Phocoena 
dioptrica). Table 2 lists all species with expected potential for 
occurrence in the Ross Sea, Antarctica, and summarizes information 
related to the population, including regulatory status under the MMPA 
and ESA.

 Table 2--Marine Mammal Species Potentially Present in the Project Area Expected To Be Affected by the Specified
                                                   Activities
----------------------------------------------------------------------------------------------------------------
                                                                       ESA/MMPA
                                                                        status;
          Common name              Scientific name     Stock \1\     Strategic (Y/         Stock abundance
                                                                        N) \2\
----------------------------------------------------------------------------------------------------------------
                      Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
Family Balaenopteridae
 (rorquals):
    Blue whale.................  Balaenoptera        N/A            E/D;Y           10,000-25,000,\5\ 1,700.\7\
                                  musculus.
    Fin whale..................  Balaenoptera        N/A            E/D;Y           140,000,\5\ 38,200.\6\
                                  physalus.
    Humpback whale.............  Megaptera           N/A            ..............  90,000-100,000,\5\
                                  novaeangliae.                                      80,000,\10\ 42,000.\11\
    Antarctic minke whale \6\..  Balaenoptera        N/A            ..............  Several 100,000,\5\
                                  bonaerensis.                                       515,000.\9\
    Sei whale..................  Balaenoptera        N/A            E               70,000.\8\
                                  borealis.
----------------------------------------------------------------------------------------------------------------
                        Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
----------------------------------------------------------------------------------------------------------------
Family Physeteridae:
    Sperm whale................  Physeter            N/A            E               360,000,\12\ 12,069.\13\
                                  macrocephalus.
Family Ziphiidae (beaked
 whales):
    Arnoux's beaked whale......  Berardius arnuxii.  N/A            ..............  599,300.\14\
    Strap-toothed beaked whale.  Mesoplodon grayi..  N/A            ..............  599,300.\14\
    Southern bottlenose whale..  Hyperoodon          N/A            ..............  599,300.\14\
                                  planifrons.
Family Delphinidae:
    Killer whale...............  Orcinus orca......  N/A            ..............  50,000,\16\ 25,000.\17\
    Long-finned pilot whale....  Globicephala        N/A            ..............  200,000.\15\
                                  macrorhynchus.
    Hourglass dolphin..........  Lagenorhynchus      NA             ..............  144,300.\15\
                                  cruciger.
Family Phocidae (earless
 seals):
    Crabeater seal.............  Lobodon             N/A            ..............  5-10 million,\18\ 1.7
                                  carcinophaga.                                      million.\19\
    Leopard seal...............  Hydrurga leptonyx.  N/A            ..............  222,000-440,00.5 20
    Southern elephant seal.....  Mirounga leonina..  N/A            ..............  750,000.\23\
    Ross seal..................  Ommatophoca rossii  N/A            ..............  250,000.\22\

[[Page 77801]]

 
    Weddell seal...............  Leptonychotes       N/A            ..............  1 million.5 21
                                  weddellii.
----------------------------------------------------------------------------------------------------------------
N.A. = data not available.
\1\ Occurrence in area at the time of the planned activities; based on professional opinion and available data.
\2\ U.S. Endangered Species Act: EN = endangered, NL = not listed.
\5\ Worldwide (Jefferson et al,. 2015).
\6\ Antarctic (Aguilar and Garc[iacute]a-Vernet 2018).
\7\ Antarctic (Branch et al., 2007).
\8\ Southern Hemisphere (Horwood 2018).
\9\ Southern Hemisphere (IWC 2020).
\10\ Southern Hemisphere (Clapham 2018).
\11\ Antarctic feeding area (IWC 2020).
\12\ Worldwide (Whitehead 2002).
\13\ Antarctic south of 60[deg]S (Whitehead 2002).
\14\ All beaked whales south of the Antarctic Convergence; mostly southern bottlenose whales (Kasamatsu and
  Joyce 1995).
\15\ Kasamatsu and Joyce (1995).
\16\ Worldwide (Forney and Wade 2006).
\17\ Minimum estimate for Southern Ocean (Branch and Butterworth 2001).
\18\ Worldwide (Bengtson and Stewart 2018).
\19\ Ross and Amundsen seas (Bengtson et al., 2011).
\20\ Rogers et al., 2018.
\21\ H[uuml]ckst[auml]dt 2018a.
\22\ Worldwide (Curtis et al., 2011 in H[uuml]ckst[auml]dt 2018b).
\23\ Total world population (Hindell et al., 2016).

    All species that could potentially occur in the survey areas are 
included in Table 2. As described below, all 17 species temporally and 
spatially co-occur with the activity to the degree that take is 
reasonably likely to occur, and we have authorized it.
    A detailed description of the species likely to be affected by the 
geophysical surveys, including brief introductions to the species and 
relevant stocks as well as available information regarding population 
trends and threats, and information regarding local occurrence, were 
provided in NSF's IHA application and summarized in the Federal 
Register notice for the proposed IHA (87 FR 59204; September 29, 2022); 
since that time, we are not aware of any changes in the status of these 
species and stocks; therefore detailed descriptions are not provided 
here. Please refer to that Federal Register notice for these 
descriptions. Please also refer to the NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 3.

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
           Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans         7 Hz to 35 kHz.
 (baleen whales).
Mid-frequency (MF) cetaceans         150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true  275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)   50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)  60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).


[[Page 77802]]

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from NSF's survey activities have 
the potential to result in behavioral harassment of marine mammals in 
the vicinity of the survey area. The notice of proposed IHA (87 FR 
59204; September 29, 2022) included a discussion of the effects of 
anthropogenic noise on marine mammals and the potential effects of 
underwater noise from NSF on marine mammals and their habitat. That 
information and analysis is incorporated by reference into this final 
IHA determination and is not repeated here; please refer to the notice 
of proposed IHA (87 FR 59204; September 29, 2022).

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, which will inform both NMFS' consideration 
of ``small numbers,'' and the negligible impact determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    All authorized takes are by Level B harassment, involving temporary 
changes in behavior. No Level A harassment is expected or authorized. 
In the sections below, we describe methods to estimate the number of 
Level B harassment events. The main sources of distributional and 
numerical data used in deriving the estimates are summarized below.
    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 hearing impairment; (2) the area or volume of water that will 
be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and (4) the 
number of days of activities. We note that while these basic factors 
can contribute to a basic calculation to provide an initial prediction 
of takes, additional information that can qualitatively inform take 
estimates is also sometimes available (e.g., previous monitoring 
results or average group size). Below, we describe the factors 
considered here in more detail and present the authorized take 
estimate.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa (rms) for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources.
    NSF's survey includes the use of impulsive seismic sources (e.g., 
GI-airgun) and continuous icebreaking, therefore the 160 and 120 dB re 
1 [mu]Pa (rms) criteria are applicable for analysis of Level B 
harassment.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). L-DEO's 
survey includes the use of impulsive and intermittent sources.
    For more information, see NMFS' 2018 Technical Guidance, which may 
be accessed at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The survey would entail the use of a 2-airgun array with a total 
discharge of 210 in\3\ at a tow depth of 1-4 m (with the worst-case 
scenario of 4 m assumed for purposes of modeling). L-DEO model results 
are used to determine the 160 dBrms radius for the 2-airgun 
array water depth ranging from 150-700 m. Received sound levels were 
predicted by L-DEO's model (Diebold et al., 2010) as a function of 
distance from the airguns, for the two 105 in\3\ airguns. This modeling 
approach uses ray tracing for the direct wave traveling from the array 
to the receiver and its associated source ghost (reflection at the air-
water interface in the vicinity of the array), in a constant-velocity 
half-space (infinite homogenous ocean layer, unbounded by a seafloor). 
In addition, propagation measurements of pulses from a 36-airgun array 
at a tow depth of 6 m have been reported in deep water (~1,600 m), 
intermediate water depth on the slope (~600-1,100 m), and shallow water 
(~50 m) in the Gulf of Mexico in 2007-2008 (Tolstoy et al., 2009; 
Diebold et al., 2010).
    For deep and intermediate water cases, the field measurements 
cannot be used readily to derive the Level A and Level B harassment 
isopleths, as at those sites the calibration hydrophone was located at 
a roughly constant depth of 350-550 m, which may not intersect

[[Page 77803]]

all the SPL isopleths at their widest point from the sea surface down 
to the maximum relevant water depth (~2,000 m) for marine mammals. At 
short ranges, where the direct arrivals dominate and the effects of 
seafloor interactions are minimal, the data at the deep sites are 
suitable for comparison with modeled levels at the depth of the 
calibration hydrophone. At longer ranges, the comparison with the 
model--constructed from the maximum SPL through the entire water column 
at varying distances from the airgun array--is the most relevant.
    In deep and intermediate water depths at short ranges, sound levels 
for direct arrivals recorded by the calibration hydrophone and L-DEO 
model results for the same array tow depth are in good alignment (see 
Figures 12 and 14 in Appendix H of NSF-USGS 2011). Consequently, 
isopleths falling within this domain can be predicted reliably by the 
L-DEO model, although they may be imperfectly sampled by measurements 
recorded at a single depth. At greater distances, the calibration data 
show that seafloor-reflected and sub-seafloor-refracted arrivals 
dominate, whereas the direct arrivals become weak and/or incoherent 
(see Figures 11, 12, and 16 in Appendix H of NSF-USGS 2011). Aside from 
local topography effects, the region around the critical distance is 
where the observed levels rise closest to the model curve. However, the 
observed sound levels are found to fall almost entirely below the model 
curve. Thus, analysis of the Gulf of Mexico calibration measurements 
demonstrates that although simple, the L-DEO model is a robust tool for 
conservatively estimating isopleths.
    The survey would acquire data with two 105-in\3\ guns at a tow 
depth of 1-4 m. For deep water (>1000 m), we use the deep-water radii 
obtained from L-DEO model results down to a maximum water depth of 
2,000 m for the airgun array. The radii for intermediate water depths 
(100-1,000 m) are derived from the deep-water ones by applying a 
correction factor (multiplication) of 1.5, such that observed levels at 
very near offsets fall below the corrected mitigation curve (see Figure 
16 in Appendix H of NSF-USGS 2011).
    L-DEO's modeling methodology is described in greater detail in 
NSF's IHA application. The estimated distances to the Level B 
harassment isopleth for the airgun configuration are shown in Table 4.

 Table 4--Predicted Radial Distances From the RVIB Palmer Seismic Source
       to Isopleths Corresponding to Level B Harassment Threshold
------------------------------------------------------------------------
                                                             Predicted
                                                           distances (m)
          Airgun configuration              Water depth      to 160 dB
                                              (m)\a\      received sound
                                                               level
------------------------------------------------------------------------
Two 105-in3 GI guns.....................          >1,000         726 \b\
                                               100-1,000       1,089 \c\
------------------------------------------------------------------------
\a\ No survey effort would occur in water >1000 m; the distance for this
  water depth is included for informational purposes only.
\b\ Distance is based on L-DEO model results.
\c\ Distance is based on L-DEO model results with a 1.5 x correction
  factor between deep and intermediate water depths.

    Table 5 presents the modeled PTS isopleths for each marine mammal 
hearing group based on the L-DEO modeling incorporated in the companion 
User Spreadsheet (NMFS 2018).

          Table 5--Modeled Radial Distances to Isopleths Corresponding to Level A Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
                                                  SEL cumulative  SEL cumulative      Pk PTS          Pk PTS
                  Hearing group                    PTS threshold   PTS distance   threshold (dB)   distance (m)
                                                     (dB) \1\         (m) \1\           \1\             \1\
----------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans.........................             183            25.4             219            6.69
Mid-frequency cetaceans.........................             185             0.0             230            1.50
High-frequency cetaceans........................             155             0.0             202           47.02
Phocid pinnipeds................................             185             0.3             218            7.53
Otariid pinnpeds................................             203             0.0             232            0.92
----------------------------------------------------------------------------------------------------------------
\1\ Cumulative sound exposure level for PTS (SELcumPTS) or Peak (SPLflat) resulting in Level A harassment (i.e.,
  injury). Based on 2018 NMFS Acoustic Technical Guidance (NMFS 2018).

    Predicted distances to Level A harassment isopleths, which vary 
based on marine mammal hearing groups, were calculated based on 
modeling performed by L-DEO using the Nucleus 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 2016a). 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 SELcum for the two-GI airgun array is derived from 
calculating the modified farfield signature. The farfield signature is 
often used as a theoretical representation of the source level. To

[[Page 77804]]

compute the farfield signature, the source level is estimated at a 
large distance (right) 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, it has been recognized that the 
source level from the theoretical farfield signature is never 
physically achieved at the source when the source is an array of 
multiple airguns separated in space (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 interactions of the two 
airguns that occur near the source center and is calculated as a point 
source (single airgun), the modified farfield signature is a more 
appropriate measure of the sound source level for large arrays. For 
this smaller array, the modified farfield changes will be 
correspondingly smaller as well, but this method is used for 
consistency across all array sizes.
    The Level B harassment estimates are based on a consideration of 
the number of marine mammals that could be within the area around the 
operating airgun array where received levels of sound >=160 dB re 1 
[mu]Parms are predicted to occur (see Table 1). The estimated numbers 
are based on the densities (numbers per unit area) of marine mammals 
expected to occur in the area in the absence of seismic surveys. To the 
extent that marine mammals tend to move away from seismic sources 
before the sound level reaches the criterion level and tend not to 
approach an operating airgun array, these estimates likely overestimate 
the numbers actually exposed to the specified level of sound.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information, that 
will inform the take calculations.
    For the planned survey area, NSF provided density data for marine 
mammal species that might be encountered in the project area. NMFS 
concurred that these data are the best available. Sightings data from 
the 2002-2003 (IWC-SOWER) Circumpolar Cruise, Area V (Ensor et al. 
2003) were used to estimate densities for four mysticete (i.e., 
humpback whale, Antarctic minke whale, fin whale, and blue whale) and 
six odontocete species (i.e., sperm whale, southern bottlenose whale, 
strap-toothed beaked whale, killer whale, long-finned pilot whale and 
hourglass dolphin). Densities for sei and Arnoux's beaked whales were 
based on those reported in the Naval Marine Species Density Database 
(NMSDD) (Department of Navy 2012). NMFS finds NMSDD a reasonable 
representation of the lower likelihood of encountering these species, 
as evidenced by previous monitoring reports from projects in the same 
or similar area (85 FR 5619; January 31, 2020 & 80 FR 4886; January 29, 
2015) and primary literature on whale species density distribution in 
the Antarctic (Cetacean Population Studies Vol.2, 2020). Densities of 
pinnipeds were estimated using best available data (Waterhouse 2001; 
Pinkerton and Bradford-Grieve 2010) and dividing the estimated 
population of pinnipeds (number of animals) by the area of the Ross Sea 
(300,000 km\2\). Estimated densities used and Level B harassment 
ensonified areas to inform take estimates are presented in Table 6.

           Table 6--Marine Mammal Densities and Total Ensonified Area of Activities in the Survey Area
----------------------------------------------------------------------------------------------------------------
                                                                     Ross Bank       Drygalski      Icebreaking
                                                     Estimated        level B     Trough level B      level B
                     Species                        density (#/     ensonified      ensonified      ensonified
                                                      km\2\)       area (km\2\)    area (km\2\)    area (km\2\)
----------------------------------------------------------------------------------------------------------------
Fin whale.......................................       0.0306570           5,272           4,942           8,278
Blue whale......................................       0.0065132
Sei whale.......................................       0.0046340
Antarctic minke whale...........................       0.0845595
Humpback whale..................................       0.0321169
Sperm whale.....................................       0.0098821
Southern bottlenose whale.......................       0.0117912
Arnoux's beaked whale...........................       0.0134420
Strap-toothed beaked whale......................       0.0044919
Killer whale....................................       0.0208872
Long-finned pilot whale.........................       0.0399777
Hourglass dolphin...............................       0.0189782
Crabeater seal..................................       0.6800000
Leopard seal....................................       0.0266700
Ross seal.......................................       0.0166700
Weddell seal....................................       0.1066700
Southern elephant seal..........................       0.0001300
----------------------------------------------------------------------------------------------------------------

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and authorized.
Seismic Surveys
    In order to estimate the number of marine mammals predicted to be 
exposed to sound levels that would result in Level B harassment, the 
radial distance from the airgun array to the predicted isopleth 
corresponding to the Level B harassment threshold is calculated, as 
described above. The radial distance is then used to calculate the area 
around the airgun array predicted to be ensonified to the sound level 
that exceed the Level B harassment threshold. The area estimated to be

[[Page 77805]]

ensonified in a single day of the survey is then calculated (Table 10), 
based on the area predicted to be ensonified around the array and the 
estimated trackline distance traveled per day. The daily ensonified 
area was then multiplied by the number of estimated seismic acquisition 
days -9.6 days for the Ross Bay survey and 9 days for the Drygalski 
Trough survey. The product is then multiplied by 1.25 to account for 
the additional 25 percent contingency, as described above. This results 
in an estimate of the total area (km\2\) expected to be ensonified to 
the Level B harassment threshold.

                                       Table 7--Area (km\2\) To Be Ensonified to the Level B Harassment Threshold
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Daily
                                                           Distance/day      Threshold      ensonified       Number of        Plus %           Total
                       Survey area                             (km)        distance (km)     area with      survey days    (contingency)    ensonified
                                                                                          endcap (km\2\)                                   area (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ross Bank...............................................             200           1.089             439             9.6              12            5272
Drygalski Trough........................................             200           1.089             439               9           11.25            4942
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on the small Level A harassment isopleths (as shown in Table 
5) and in consideration of the mitigation measures (see Mitigation 
section below), take by Level A harassment is not expected to occur and 
is not authorized.
    The marine mammals predicted to occur within the respective areas, 
based on estimated densities (Table 6), are assumed to be incidentally 
taken. Estimated take, and percentages of the stocks estimated to be 
taken, for the survey are shown in Table 12.
Icebreaking
    Applying the maximum estimated amount of icebreaking expected by 
NSF, i.e. 500 km, we calculate the total ensonified area of icebreaking 
(Table 8). Estimates of exposures assume that there would be 
approximately 2 days of icebreaking activities; the calculated takes 
have been increased by 25 percent (2.75 days).

                                                   Table 8--Ensonified Area for Icebreaking Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Daily
                                                      Distance/day      Threshold     ensonified area     Number of         Plus 25%          Total
                     Criteria                             (km)        distance (km)     with endcap      survey days     (contingency)   ensonified area
                                                                                          (km\2\)                                            (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
120 db............................................             223            6.456             3010              2.2             2.75             8278
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Estimated take from icebreaking for the survey are shown in Table 
12. As most cetaceans do not occur in pack ice, the estimates of the 
numbers of marine mammals potentially exposed to sounds greater than 
the Level B harassment threshold (120 dB re 1 [mu]Pa rms) are 
precautionary and probably overestimate the actual numbers of marine 
mammals that could be involved. No takes by Level A harassment are 
expected or authorized. The estimated number of takes for pinnipeds 
accounts for both seals that may be in the water and those hauled out 
on ice surfaces. Few cetaceans are expected to be seen during 
icebreaking activities, although some could occur along the ice margin.

                   Table 9--Total Marine Mammal Take Estimated for the Survey in the Ross Sea
----------------------------------------------------------------------------------------------------------------
                                           Level B take
             Species             --------------------------------   Total take      Population      Percent of
                                    All Seismic     Icebreaking     authorized       abundance      population
----------------------------------------------------------------------------------------------------------------
Fin whale.......................             313             254             567          38,200            1.48
Blue whale......................              67              54             121           1,700            7.12
Sei whale.......................              47              38              85          10,000            0.85
Antarctic minke whale...........             864             700           1,564         515,000             0.3
Humpback whale..................             328             266             594          42,000            1.41
Sperm whale.....................             101              82             183          12,069            1.51
Southern bottlenose whale.......             120              98             218         599,300            0.04
Arnoux's beaked whale...........             137             111             249         599,300            0.04
Strap-toothed beaked whale......              46              37              83         599,300            0.01
Killer whale....................             213             173             386          25,000            1.55
Long-finned pilot whale.........             408             331             739         200,000            0.37
Hourglass dolphin...............             194             157             351         144,300            0.24
Crabeater seal..................           6,946           5,629          12,575       1,700,000               1
Leopard seal....................             272             221             493         220,000            0.22
Ross seal.......................             170             138             308         250,000            0.12
Weddell seal....................           1,090             883           1,973       1,000,000             0.2
Southern elephant seal..........               2               1               3         750,000           <0.01
----------------------------------------------------------------------------------------------------------------


[[Page 77806]]

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, and impact on 
operations.
    Mitigation measures that would be adopted during the planned survey 
include, but are not limited to: (1) Vessel speed or course alteration, 
provided that doing so would not compromise operation safety 
requirements. (2) GI-airgun shut down within exclusion zones (EZ)s, and 
(3) ramp-up procedures.

Vessel-Visual Based Mitigation Monitoring

    Visual monitoring requires the use of trained observers (herein 
referred to as visual protected species observers (PSOs)) to scan the 
ocean surface visually for the presence of marine mammals. The area to 
be scanned visually includes primarily the exclusion zone, within which 
observation of certain marine mammals requires shutdown of the acoustic 
source, but also the buffer zone. The buffer zone means an area beyond 
the exclusion zone to be monitored for the presence of marine mammals 
that may enter the exclusion zone. During pre-start clearance (i.e., 
before ramp-up begins), the buffer zone also acts as an extension of 
the exclusion zone in that observations of marine mammals within the 
buffer zone would also prevent airgun operations from beginning (i.e., 
ramp-up). The buffer zone encompasses the area at and below the sea 
surface from the edge of the 100 m exclusion zone measured from the 
edges of the airgun array. Visual monitoring of the exclusion zone and 
adjacent waters is intended to establish and, when visual conditions 
allow, maintain zones around the sound source that are clear of marine 
mammals, thereby reducing or eliminating the potential for injury and 
minimizing the potential for more severe behavioral reactions for 
animals occurring closer to the vessel. Visual monitoring of the buffer 
zone is intended to (1) provide additional protection to na[iuml]ve 
marine mammals that may be in the area during pre-clearance, and (2) 
during airgun use, aid in establishing and maintaining the exclusion 
zone by altering the visual observer and crew of marine mammals that 
are outside of, but may approach and enter, the exclusion zone.
    NSF must use independent, dedicated, trained visual PSOs, meaning 
that the PSOs must be employed by a third-party observer provider, must 
not have tasks other than to conduct observational effort, collect 
data, and communicate with and instruct relevant vessel crew with 
regard to the presence of protected species and mitigation 
requirements, and must have successfully completed an approved PSO 
training course. PSO resumes shall be provided to NMFS for approval.
    At least one visual PSO must have a minimum of 90 days at-sea 
experience working in that role during a shallow penetration or low-
energy survey, with no more than 18 months elapsed since the conclusion 
of the at-sea experience. One PSO with such experience shall be 
designated as the lead for the entire protected species observation 
team. The lead PSO shall serve as primary point of contact for the 
vessel operator and ensure all PSO requirements per the IHA are met. To 
the maximum extent practicable, the experienced PSOs should be 
scheduled to be on duty with those PSOs with the appropriate training 
but who have not yet gained relevant experience.
    During survey operations (e.g., any day on which use of the 
acoustic source is planned to occur, and whenever the acoustic source 
is in the water, whether activated or not), a minimum of one PSO must 
be on duty and conducting visual observations at all times during 
daylight hours (i.e., from 30 minutes prior to sunrise through 30 
minutes following sunset) and 30 minutes prior to and during ramp-up of 
the airgun array. Visual monitoring of the exclusion and buffer zones 
must begin no less than 30 minutes prior to ramp-up and must continue 
until one hour after use of the acoustic source ceases or until 30 
minutes past sunset. Visual PSOs must coordinate to ensure 360 degree 
visual coverage around the vessel from the most appropriate observation 
posts, and must conduct visual observations using binoculars and the 
naked eye while free from distractions and in a consistent, systematic, 
and diligent manner.
    PSOs shall establish and monitor the exclusion and buffer zones. 
These zones shall be based upon the radial distance from the edges of 
the acoustic source (rather than being based on the center of the array 
or around the vessel itself). During use of the acoustic source (i.e., 
anytime airguns are active, including ramp-up) shall be communicated to 
the operator to prepare for the potential shutdown of the acoustic 
source.
    During use of the airgun, detections of marine mammals within the 
buffer zone (but outside the exclusion zone) should be communicated to 
the operator to prepare for the potential shutdown of the acoustic 
source. 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 sightings 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.

[[Page 77807]]

Exclusion Zone and Buffer Zone

    An exclusion zone (EZ) is a defined area within which occurrence of 
a marine mammal triggers mitigation action intended to reduce the 
potential for certain outcome, e.g., auditory injury, disruption of 
critical behaviors. The PSOs would establish a minimum EZ with a 100 m 
radius with an additional 100 m buffer zone (total of 200 m). The 200m 
zone 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). With certain exceptions (described below), if a marine 
mammal appears within or enters this zone, the acoustic source would be 
shut down.
    The 100 m EZ, with additional 100 m buffer zone, is intended to be 
precautionary in the sense that it would be expected to contain sound 
exceeding the injury criteria for all cetacean hearing groups, (based 
on the dual criteria of SELcum and peak SPL), while also 
providing a consistent, reasonably observable zone within which PSOs 
would typically be able to conduct effective observational effort. 
Additionally, a 100 m EZ is expected to minimize the likelihood that 
marine mammals will be exposed to levels likely to result in more 
severe behavioral responses. Although significantly greater distances 
may be observed from an elevated platform under good conditions, we 
believe that 100 m is regularly attainable for PSOs using the naked eye 
during typical conditions.
    An extended 500 m exclusion zone must be established for beaked 
whales, large whales 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 an aggregation of six or more whales during all 
survey effort. No buffer zone is required.

Pre-Clearance and Ramp-up

    Ramp-up (sometimes referred to as ``soft start'') is the gradual 
and systematic increase of emitted sound levels from an airgun array. 
Ramp-up would begin with one GI airgun 45 cu in first being activated, 
followed by the second after 5 minutes. The intent of pre-clearance 
observation (30 minutes) is to ensure no marine mammals are observed 
within the buffer zone prior to the beginning of ramp-up. During pre-
clearance is the only time observations of marine mammals in the buffer 
zone 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 stepwise increase 
in the number of airguns are activated and the full volume is achieve, 
is required at all times as part of the activation of the acoustic 
source. All operators must adhere to the following pre-clearance and 
ramp-up requirements:
    (1) The operator must notify a designated PSO of the planned start 
of ramp-up as agreed upon with the lead PSO; the notification time 
should not be less than 60 minutes prior to the planned ramp-up in 
order to allow PSOs time to monitor the exclusion and buffer zones for 
30 minutes prior to the initiation of ramp-up (pre-clearance);
     Ramp-ups shall be scheduled so as to minimize the time 
spent with the source activated prior to reaching the designated run-
in;
     One of the PSOs conducting pre-clearance observations must 
be notified again immediately prior to initiating ramp-up procedures 
and the operator must receive confirmation from the PSO to proceed;
     Ramp-up may not be initiated if any marine mammal is 
within the applicable exclusion or buffer zone. If a marine mammal is 
observed within the applicable exclusion zone or the buffer zone during 
the 30 minutes pre-clearance period, ramp-up may not begin until the 
animal(s) has been observed exiting the zones or until an additional 
time period has elapsed with no further sightings (15 minutes for small 
odontocetes and pinnipeds, and 30 minutes for Mysticetes and all other 
odontocetes, including sperm whales and beaked whales);
     PSOs must monitor the exclusion and buffer zones during 
ramp-up, and ramp-up must cease and the source must be shut down upon 
detection of a marine mammal within the applicable exclusion zone. Once 
ramp-up has begun, detections of marine mammals within the buffer zone 
do not require shutdown, but such observation shall be communicated to 
the operator to prepare for the potential shutdown; and
    (2) If the acoustic source is shut down for brief periods (i.e., 
less than 30 minutes) for reasons other than that described for 
shutdown (e.g., mechanical difficulty), it may be activated again 
without ramp-up if PSOs have maintained constant observation and no 
detections of marine mammals have occurred within the applicable 
exclusion zone. For any longer shutdown, pre-start clearance 
observation and ramp-up are required. For any shutdown at night or in 
periods of poor visibility (e.g., BSS 4 or greater), ramp-up is 
required, but if the shutdown period was brief and constant observation 
was maintained, pre-start clearance watch is not required.
     Testing of the acoustic source involving all elements 
requires ramp-up. Testing limited to individual source elements does 
not require ramp-up but does require pre-start clearance watch.

Shutdown Procedures

    The shutdown of an airgun array requires the immediate de-
activation of all individual airgun elements of the array. Any PSO on 
duty will have the authority to delay the start of survey operations or 
to call for shutdown of the acoustic source if a marine mammal is 
detected within the applicable exclusion zone. The operator must also 
establish and maintain clear lines of communication directly between 
PSOs on duty and crew controlling the acoustic source to ensure that 
shutdown commands are conveyed swiftly while allowing PSOs to maintain 
watch. When the airgun array is active (i.e., anytime one or more 
airguns is active, including during ramp-up) and (1) a marine mammal 
appears within or enters the applicable exclusion zone 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 minutes in the case of 
small odontocetes and pinnipeds, and 30 minutes for Mysticetes and all 
other odontocetes, including sperm and beaked whales, with no further 
observation of the marine mammal(s).
    Upon implementation of shutdown, the source may be reactivated 
after the marine mammal(s) has been observed exiting the applicable 
exclusion zone (i.e., animal is not required to fully exit the buffer 
zone where applicable) or following a clearance period (15 minutes for 
small odontocetes and pinnipeds, and 30 minutes for mysticetes and all 
other odontocetes, including sperm whales, beaked whales, pilot whales, 
killer whales, and Risso's dolphin) with no further observation of the 
marine mammal(s).
    NSF must implement shutdown if a marine mammal species for which 
take was not authorized, or a species for which authorization was 
granted but the takes have been met, approaches the Level B harassment 
zones.

[[Page 77808]]

Vessel Strike Avoidance Measures

    These measures apply to all vessels associated with the planned 
survey activity; however, we note that these requirements do not apply 
in any case where compliance would create an imminent and serious 
threat to a person or vessel or to the extent that a vessel is 
restricted in its ability to maneuver and, because of the restriction, 
cannot comply. These measures include the following:
    (1) Vessel operators and crews must maintain a vigilant watch for 
all marine mammals and slow down, stop their vessel, or alter course, 
as appropriate and regardless of vessel size, to avoid striking any 
marine mammal. A single marine mammal at the surface may indicate the 
presence of submerged animals in the vicinity of the vessel; therefore, 
precautionary measures should be exercised when an animal is observed. 
A visual observer aboard the vessel must monitor a vessel strike 
avoidance zone around the vessel (specific distances detailed below), 
to ensure the potential for strike is minimized. Visual observers 
monitoring the vessel strike avoidance zone can be either third-party 
observers or crew members, but crew members responsible for these 
duties must be provided sufficient training to distinguish marine 
mammals from other phenomena and broadly to identify a marine mammal to 
broad taxonomic group (i.e., as a large whale or other marine mammal);
    (2) Vessel speeds must be reduced to 10 kn or less when mother/calf 
pairs, pods, or large assemblages of any marine mammal are observed 
near a vessel;
    (3) All vessels must maintain a minimum separation distance of 100 
m from large whales (i.e., sperm whales and all mysticetes);
    (4) All vessels must attempt to maintain a minimum separation 
distance of 50 m from all other marine mammals, with an exception made 
for those animals that approach the vessel; and
    (5) When marine mammals are sighted while a vessel is underway, the 
vessel should take action as necessary to avoid violating the relevant 
separation distance (e.g., attempt to remain parallel to the animal's 
course, avoid excessive speed or abrupt changes in direction until the 
animal has left the area). If marine mammals are sighted within the 
relevant separation distance, the vessel should reduce speed and shift 
the engine to neutral, not engaging the engines until animals are clear 
of the area. This recommendation does not apply to any vessel towing 
gear.
    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the mitigation measures provide the means of 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Vessel-Based Visual Monitoring

    As described above, PSO observations would take place during 
daytime airgun operations. During seismic operations, at least three 
visual PSO would be based aboard the Palmer, with a minimum of one on 
duty at all times during daylight hours. NMFS' typical requirements for 
surveys of this type include a minimum of two PSOs on duty at all times 
during daylight hours. However, NSF stated in communications with NMFS 
that the requirement is not practicable in this circumstance due to the 
remote location of the survey and associated logistical issues, 
including limited capacity to fly PSOs into and out of McMurdo Station 
in Antarctica and limited berth space on the Palmer, and requested an 
exception to the requirement. NMFS agrees that, in this circumstance, 
the requirement to have a minimum of two PSOs on duty during all 
daylight hours would be impracticable and, therefore, a minimum of one 
PSO must be on duty. NSF must employ two PSOs on duty during all 
daylight hours to the maximum extent practicable. NSF Monitoring shall 
be conducted in accordance with the following requirements:
    (1) PSOs shall be independent, dedicated and trained and must be 
employed by a third-party observer provider;
    (2) The operator must work with the selected third-party observer 
provider to ensure PSOs have all equipment (including backup equipment) 
needed to adequately perform necessary tasks, including accurate 
determination of distance and bearing to observed marine mammals. Such 
equipment, at a minimum, must include:
     Reticle binoculars (e.g., 7 x 50) of appropriate quality 
(at least one per PSO, plus backups).
     Global Positioning Unit (GPS) (plus backup).
     Digital single-lens reflex cameras of appropriate quality 
that capture photographs and video (plus backup).
     Compass (plus backup)
     Radios for communication among vessel crew and PSOs (at 
least one per PSO, plus backups).
     Any other tools necessary to adequately perform necessary 
PSO tasks.
    (3) PSOs shall have no tasks other than to conduct visual 
observational effort, collect data, and communicate with and instruct 
relevant vessel crew with regard to the presence of protected

[[Page 77809]]

species and mitigation requirements (including brief alerts regarding 
maritime hazards);
    (4) PSOs shall have successfully completed an approved PSO training 
course appropriate for their designated task (visual or acoustic);
    (5) 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;
    (6) 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;
    (7) 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;
    (8) 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
    (9) 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:
     secondary education and/or experience comparable to PSO 
duties;
     previous work experience conducting academic, commercial, 
or government-sponsored protected species surveys; or
     previous work experience as a PSO; the PSO should 
demonstrate good standing and consistently good performance of PSO 
duties.
    PSOs must use standardized data collection forms, whether hard copy 
or electronic. PSOs must record detailed information about any 
implementation of mitigation requirements, including the distance of 
animals to the acoustic source and description of specific actions that 
ensued, the behavior of the animal(s), any observed changes in behavior 
before and after implementation of mitigation, and if shutdown was 
implemented, the length of time before any subsequent ramp-up of the 
acoustic source. If required mitigation was not implemented, PSOs 
should record a description of the circumstances. At a minimum, the 
following information must be recorded:
     Vessel name and call sign;
     PSO names and affiliations;
     Date and participants of PSO briefings (as discussed in 
General Requirement);
     Dates of departure and return to port with port name;
     Dates and times (Greenwich Mean Time) of survey effort and 
times corresponding with PSO effort;
     Vessel location (latitude/longitude) when survey effort 
began and ended and vessel location at beginning and end of visual PSO 
duty shifts;
     Vessel heading and speed at beginning and end of visual 
PSO duty shifts and upon any line change;
     Environmental conditions while on visual survey (at 
beginning and end of PSO shift and whenever conditions changed 
significantly), including BSS and any other relevant weather conditions 
including cloud cover, fog, sun glare, and overall visibility to the 
horizon;
     Factors that may have contributed to impaired observations 
during each PSO shift change or as needed as environmental conditions 
changed (e.g., vessel traffic, equipment malfunctions); and
     Survey activity information, such as acoustic source power 
output while in operation, number and volume of airguns operating in 
the array, tow depth of the array, and any other notes of significance 
(i.e., pre-start clearance, ramp-up, shutdown, testing, shooting, ramp-
up completion, end of operations, streamers, etc.).
    The following information should be recorded upon visual 
observation of any marine mammal:
     Watch status (sighting made by PSO on/off effort, 
opportunistic, crew, alternate vessel/platform);
     PSO who sighted the animal;
     Time of sighting;
     Vessel location at time of sighting;
     Water depth;
     Direction of vessel's travel (compass direction);
     Direction of animal's travel relative to the vessel;
     Pace of the animal;
     Estimated distance to the animal and its heading relative 
to vessel at initial sighting;
     Identification of the animal (e.g., genus/species, lowest 
possible taxonomic level, or unidentified) and the composition of the 
group if there is a mix of species;
     Estimated number of animals (high/low/best);
     Estimated number of animals by cohort (adults, yearlings, 
juveniles, calves, group composition, etc.);
     Description (as many distinguishing features as possible 
of each individual seen, including length, shape, color, pattern, scars 
or markings, shape and size of dorsal fin, shape of head, and blow 
characteristics);
     Detailed behavior observations (e.g., number of blows/
breaths, number of surfaces, breaching, spyhopping, diving, feeding, 
traveling; as explicit and detailed as possible; note any observed 
changes in behavior);
     Animal's closest point of approach (CPA) and/or closest 
distance from any element of the acoustic source;
     Platform activity at time of sighting (e.g., deploying, 
recovering, testing, shooting, data acquisition, other); and
     Description of any actions implemented in response to the 
sighting (e.g., delays, shutdown, ramp-up) and time and location of the 
action.

Reporting

    NSF must submit a draft comprehensive report to NMFS on all 
activities and monitoring results within 90 days of the completion of 
the survey or expiration of the IHA, whichever comes sooner. 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 
report would also include estimates of the number and nature of 
exposures that occurred above the harassment threshold based on PSO 
observations and including an estimate of those that were not detected, 
in consideration of both the characteristics and behaviors of the 
species of marine mammals that affect detectability, as well as the 
environmental factors that affect detectability.
    The draft report shall also include geo-referenced time-stamped 
vessel tracklines for all time periods during which airguns were 
operating. Tracklines should include points recording any change in 
airgun status (e.g., when the airguns began operating, when they were 
turned off, or when they changed from full array to single gun or vice 
versa). Geographic

[[Page 77810]]

Information System (GIS) files shall be provided in Environmental 
Systems Research Institute (ESRI) shapefile format and include the 
Coordinated Universal Time (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.

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 NSF shall report the 
incident to the Office of Protected Resources (OPR), NMFS as soon as 
feasible. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.
    Vessel strike--In the event of a ship strike of a marine mammal by 
any vessel involved in the activities covered by the authorization, L-
DEO shall report the incident to Office of Protected Resources (OPR), 
NMFS and to the NMFS West Coast Regional Stranding Coordinator as soon 
as feasible. The report must include the following information:
     Time, date, and location (latitude/longitude) of the 
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., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338; 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the discussion of our analysis applies to all 
the species listed in Table 6, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar, except where a species- or stock-specific discussion is 
warranted. NMFS does not anticipate that serious injury or mortality 
would occur as a result from low-energy survey, even in the absence of 
mitigation, and no serious injury or mortality is authorized. As 
discussed in the Potential Effects of Specified Activities on Marine 
Mammals and their Habitat section, non-auditory physical effects and 
vessel strike are not expected to occur. NMFS expects that all 
potential take would be in the form of Level B behavioral harassment in 
the form of temporary avoidance of the area or decreased foraging (if 
such activity was occurring), responses that are considered to be of 
low severity, and with no lasting biological consequences (e.g., 
Southall et al., 2007, 2021). These low-level impacts of behavioral 
harassment are not likely to impact the overall fitness of any 
individual or lead to population level effects of any species. As 
described above, Level A harassment is not expected to occur given the 
estimated small size of the Level A harassment zones.
    In addition to being temporary, the maximum expected Level B 
harassment zone around the survey vessel is 1,089 m (and as much a 
6,456 m for icebreaking activities). Therefore, the ensonified area 
surrounding the vessel is relatively small compared to the overall 
distribution of animals in the area and their use of the habitat. 
Feeding behavior is not likely to be significantly impacted as prey 
species are mobile and are broadly distributed throughout the survey 
area; therefore, marine mammals that may be temporarily displaced 
during survey activities are expected to be able to resume foraging 
once they have moved away from areas with disturbing levels of 
underwater noise. Because of the short duration (19 days) and temporary 
nature of the disturbance and the availability of similar habitat and 
resources in the surrounding area, the impacts to marine mammals and 
the food sources that they utilize are not expected to cause 
significant or long-term consequences for individual marine mammals or 
their populations.
    NMFS does not anticipate that serious injury or mortality would 
occur as a result of NSF's seismic survey, even in the absence of 
mitigation. Thus, the authorization does not authorize any serious 
injury or mortality. As discussed in the Potential Effects of Specified 
Activities on Marine Mammals and their Habitat section, non-auditory 
physical effects, stranding, and vessel strike are not expected to 
occur.

[[Page 77811]]

    No takes by Level A harassment are authorized. The 100-m EZ 
encompasses the Level A harassment isopleths for all marine mammal 
hearing groups, and is expected to prevent animals from being exposed 
to sound levels that would cause PTS. Also, as described above, we 
expect that marine mammals would be likely to move away from a sound 
source that represents an aversive stimulus, especially at levels that 
would be expected to result in PTS, given sufficient notice of the RVIB 
Palmer's approach due to the vessel's relatively low speed when 
conducting seismic survey. We expect that any instances of take 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).
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see Potential Effects of Specified 
Activities on Marine Mammals and their Habitat). Marine mammal habitat 
may be impacted by elevated sound levels, but these impacts would be 
temporary. Feeding behavior is not likely to be significantly impacted, 
as marine mammals appear to be less likely to exhibit behavioral 
reactions or avoidance responses while engaged in feeding activities 
(Richardson et al., 1995). 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 temporary nature 
of the disturbance, the availability of similar habitat and resources 
in the surrounding area, and the lack of important or unique marine 
mammal habitat, 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. In 
addition, there are no feeding, mating or calving areas known to be 
biologically important to marine mammals within the project area.
    As explained above in the Description of Marine Mammals in the Area 
of Specified Activities section, marine mammals in the survey area are 
not assigned to NMFS stocks. Therefore, we rely on the best available 
information on the abundance estimates for the species of marine 
mammals that could be taken. The activity is expected to impact a very 
small percentage of all marine mammal populations that would be 
affected by NSF's survey (approximately three percent or less each for 
all marine mammal populations where abundance estimates exist). 
Additionally, the acoustic ``footprint'' of the survey would be very 
small relative to the ranges of all marine mammal species that would 
potentially be affected. Sound levels would increase in the marine 
environment in a relatively small area surrounding the vessel compared 
to the range of the marine mammals within the survey area. The seismic 
array would be active 24 hours per day throughout the duration of the 
survey. However, the very brief overall duration of the survey (19 
days) would further limit potential impacts that may occur as a result 
of the activity.
    The 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 ramp-ups and shutdowns of the 
airgun array.
    Of the marine mammal species that are likely to occur in the 
project area, the following species are listed as endangered under the 
ESA: blue, fin, sei, and sperm whales. We are proposing to authorize 
very small numbers of takes for these species (Table 11 and Table 13), 
relative to their population sizes (again, for species where population 
abundance estimates exist), therefore we do not expect population-level 
impacts to any of these species. The other marine mammal species that 
may be taken by harassment during NSF's seismic survey are not listed 
as threatened or endangered under the ESA. There is no designated 
critical habitat for any ESA-listed marine mammals within the project 
area.
    NMFS concludes that exposures of marine mammals due to NSF's 
planned seismic survey would result in only short-term (temporary and 
short in duration) effects to individuals exposed. Marine mammals 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 take estimates to impact annual rates of recruitment or 
survival.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
    (1) No mortality, serious injury or Level A harassment is 
anticipated or authorized;
    (2) The anticipated impacts of the activity on marine mammals would 
primarily be temporary behavioral changes of small percentages of the 
affected species due to avoidance of the area around the survey vessel. 
The relatively short duration of the survey (19 days) would further 
limit the potential impacts of any temporary behavioral changes that 
would occur;
    (3) The availability of alternate areas of similar habitat value 
for marine mammals to temporarily vacate the survey area during the 
survey to avoid exposure to sounds from the activity;
    (4) The potential adverse effects of the survey on fish or 
invertebrate species that serve as prey species for marine mammals 
would be temporary and spatially limited; and
    (5) The mitigation measures, including visual monitoring, ramp-ups, 
and shutdowns, are expected to minimize potential impacts to marine 
mammals.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the 
activity would have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted previously, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS authorizes is below one third of the 
estimated stock abundance for all species (in fact, take of individuals 
is less than ten percent of the abundance of the affected stocks, see 
Table 6). This is likely a conservative

[[Page 77812]]

estimate because we assume all takes are of different individual 
animals, which is likely not the case. Some individuals may be 
encountered multiple times in a day, but PSOs would count them as 
separate individuals if they cannot be identified.
    Based on the analysis contained herein of the activity (including 
the mitigation and monitoring measures) and the anticipated take of 
marine mammals, NMFS finds that small numbers of marine mammals would 
be taken relative to the population size of the affected species or 
stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

National Environmental Policy Act

    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 action (i.e., the issuance of an IHA) with respect 
to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has determined 
that the issuance of the IHA qualifies to be categorically excluded 
from further NEPA review.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we authorize take for endangered or 
threatened species, in this case with the ESA Interagency Cooperation 
Division within NMFS' OPR.
    The NMFS Office of Protected Resources (OPR) ESA Interagency 
Cooperation Division issued a Biological Opinion under section 7 of the 
ESA, on the issuance of an IHA to NSF under section 101(a)(5)(D) of the 
MMPA by the NMFS OPR Permits and Conservation Division. The Biological 
Opinion concluded that the action is not likely to jeopardize the 
continued existence of ESA-listed blue whales, fin whales, sei whales, 
and sperm whales. There is no designated critical habitat in the action 
area for any ESA-listed marine mammal species.

Authorization

    As a result of these determinations, NMFS has issued an IHA to NSF 
for conducting seismic survey and icebreaking in the Ross Sea, in 
January through February 2023, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated. 
The IHA can be found at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-national-science-foundation-office-polar-programs-geophysical.

    Dated: December 14, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2022-27498 Filed 12-19-22; 8:45 am]
BILLING CODE 3510-22-P