[Federal Register Volume 84, Number 216 (Thursday, November 7, 2019)]
[Notices]
[Pages 60059-60076]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-24265]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XR056]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Low-Energy Geophysical Survey in 
the South Atlantic Ocean

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

ACTION: Notice; Issuance of an Incidental Harassment Authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the Scripps Institute of Oceanography (SIO) to incidentally harass, by 
Level B harassment only, marine mammals during a low-energy marine 
geophysical survey in the South Atlantic Ocean.

DATES: This Authorization is applicable from November 3, 2019 through 
November 2, 2020.

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

SUPPLEMENTARY INFORMATION: 

Background

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

Summary of Request

    On May 15, 2019, NMFS received a request from SIO for an IHA to 
take marine mammals incidental to conducting a low-energy marine 
geophysical survey in the South Atlantic Ocean. The application was 
deemed adequate and complete on August 12, 2019. SIO's request was for 
take of a small number of 48 species of marine mammals by Level B 
harassment. Neither SIO nor NMFS expects serious injury or mortality to 
result from this activity and, therefore, an IHA is appropriate.

Description of Planned Activity

    SIO plans to conduct low-energy marine seismic surveys in the South 
Atlantic Ocean during November-December 2019. The seismic surveys would 
be conducted to understand the volcanic and tectonic development of 
Walvis Ridge and Rio Grande Rise in the South Atlantic Ocean. The 
seismic surveys would be conducted in International Waters with water 
depths ranging from approximately 500 to 5700 m. The surveys would 
involve one source vessel, R/V Thomas G. Thompson (Thompson). The 
Thompson would deploy up to two 45-in \3\ GI airguns at a depth of 2-4 
m with a maximum total volume of ~90 in \3\ along predetermined 
tracklines. Seismic surveys would occur in five survey areas including 
Libra Massif in the Southwest Atlantic and Valdivia Bank, Gough, 
Tristan, and Central survey areas in the Southeast Atlantic.
    SIO proposes to conduct low-energy seismic surveys low-energy 
seismic surveys in five areas in the South Atlantic Ocean. 
Reconnaissance Surveys are planned for three survey areas (Gough, 
Tristan, Central) and High Quality Surveys are planned to take place 
along the planned seismic transect lines in the main survey area 
(Valdivia Bank) and Libra Massif survey area (Figure 1). However, High-
Quality Surveys may be replaced by Reconnaissance Surveys depending on 
weather conditions and timing (e.g., 10 percent of survey effort at 
Valdivia Bank is expected to consist of Reconnaissance Surveys). All 
data acquisition in the Tristan survey area would occur in water >1000 
m deep; all other survey areas have effort in intermediate (100-1,000 
m) and deep (>1,000 m) water. Most of the survey effort (97 percent) 
would occur in water >1000 m deep. The planned surveys would be in 
support of a potential future International Ocean Discovery Program 
(IODP) project and to improve our understanding of volcanic and 
tectonic development of oceanic ridges and to enable the selection and 
analysis of potential future IODP drill sites. To achieve the program's 
goals, the Principal Investigators propose to collect low-energy, high-
resolution multi-channel seismic (MCS) profiles. The planned cruise 
would consist of digital bathymetric, echosounding, and MCS surveys.

[[Page 60060]]

    The highest-quality mode is carried out using a pair of 45-in\3\ 
airguns, with airguns spaced 2 m apart at a depth of 2-4 m, with a 400, 
800, or 1,600 m hydrophone streamer and with the vessel traveling at to 
5 knots (5 kn) to achieve high-quality seismic reflection data. The 
reconnaissance mode is carried out using either one or two 45-in \3\ 
airguns, with airguns spaced 8 m apart (if 2 are being used) at a water 
depth of 2-4 m, with a 200 m hydrophone streamer and with the vessel 
traveling at 8 kn. The receiving system would consist of one hydrophone 
streamer, 200 to 1,600 m in length, as described below. 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.
    In addition to the operations of the airgun array, a hull-mounted 
multibeam echosounder (MBES) and a sub-bottom profiler (SBP) would also 
be operated from the Thompson continuously throughout the seismic 
surveys, but not during transits to and from the project area. All 
planned data acquisition and sampling activities would be conducted by 
SIO and UW with on board assistance by the scientists who have planned 
the project. The vessel would be self-contained, and the crew would 
live aboard the vessel for the entire cruise.
    For additional details on the planned activities, please refer to 
the notice of the proposed IHA that was published in the Federal 
Register on September 30, 2019 (84 FR 51886).
    Planned mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Mitigation and 
Monitoring and Reporting sections).

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to SIO was published in 
the Federal Register on September 30, 2019 (84 FR 51886). That notice 
described, in detail, SIO's activity, the marine mammal species that 
may be affected by the activity, and the anticipated effects on marine 
mammals. During the 30-day public comment period, NMFS received a 
comment letter from the Marine Mammal Commission (Commission).
    Comment: The Commission recommended the calculated Level A 
harassment takes should have been added to the authorized Level B 
harassment takes for the following species: 400 to 404 authorized takes 
by Level B harassment for both Antarctic and common minke whales; 3,414 
to 3,718 authorized takes by Level B harassment for short beaked common 
dolphin; 17 to 18 authorized takes by Level B harassment for pygmy 
sperm whales; 12 to 13 authorized takes by Level B harassment for dwarf 
sperm whales; and 54 to 58 authorized takes by Level B harassment for 
hourglass dolphins.
    Response: NMFS agreed and made those revisions to the authorized 
takes by Level B harassment. Instances of take by Level A and Level B 
harassment are independently calculated. The instances of take by Level 
A harassment are typically subtracted from the take by Level B 
harassment before being presented in the Estimated Take section to 
ensure they are not double-counted. Since the likelihood of take by 
Level A harassment was qualitatively ruled out, the calculated take by 
Level A harassment were previously deducted, but are now added back in 
to the authorized take by Level B harassment.
    Comment: The Commission noted some minor errors of the monitoring 
requirements between the preamble and the draft IHA.
    Response: NMFS agreed and made those corrections to ensure 
consistency with this final notice and the IHA.
    Comment: The Commission recommended revising the group size for 
Clymene dolphins from 35 to 122 animals, killer whales from 5 to 8 
animals, and false killer whales from 19 to 35 (Di Tullio et al., 2016) 
and making those appropriate changes to the authorized takes by Level B 
harassment for those species as their total takes were based on group 
size.
    Response: NMFS agreed that the group sizes for Clymene dolphins, 
killer whales, and false killer whales from Di Tullio et al., 2016 were 
more recent that the previous group sizes cited and made those 
revisions to the authorized takes by Level B harassment.
    Comment: In the context of a broader criticism of perceived 
modeling flaws, the Commission recommended NMFS specify why it believes 
that sound channels with downward refraction, as well as seafloor 
refractions, are not likely to occur during SIO's survey and the degree 
to which both of these parameters would affect the estimation (or 
underestimation) of Level B harassment zones in deep and intermediate 
water depths.
    Response: The L-DEO approach to the modeling is generally 
conservative as supported by data collected from calibration and other 
field data along with modeling results. The L-DEO approach does not 
rely on incorporating every possible environmental factor in the marine 
environment and while sound channels with downward refraction or 
seafloor refractions could potentially occur, NMFS disagrees with the 
Commission that these features need be explicitly addressed through the 
model given the conservative approach taken. Published results from 
Tolstoy (2009), Diebold (2010), and Crone et al. (2014, 2017), along 
with nearly 20 years of PSO observations from previous NSF-funded 
seismic surveys in various water depths validate the approach. L-DEO 
has presented their modeling approach to NMFS and the Commission on 
several occasions. Given the information presented, numerous 
discussions, and observations from past NSF-funded seismic surveys that 
used the L-DEO modeling approach, NMFS remains confident that the 
methodology used is appropriate and conservatively protects marine 
mammals.
    Comment: The Commission noted tables depicting source levels in 
both the IHA application and the Federal Register notice contained 
inadequate information and that the appendices of SIO's IHA application 
did not contain necessary information. The Commission recommended that 
NMFS ensure that all source levels, modified source levels, and related 
adjustment factors are specified and all relevant isopleth figures and 
user spreadsheet tables are included in all future NSF-funded and -
affiliated applications prior to processing them.
    Response: NMFS has added clarification on the tables noted by the 
Commission and provided the Commission the requested information. NMFS 
will ensure that all applications contain the necessary information 
required for adequate understanding of the acoustic modeling prior to 
publishing the notice of proposed IHA.
    Comment: The Commission recommended that, instead of using the LDEO 
modeling described in the IHA application, NMFS require LDEO to re-
estimate the Level A and Level B harassment zones and associated takes 
of marine mammals using (1) both operational (including number/type/
spacing of airguns, tow depth, source level/operating pressure, 
operational volume) and site-specific environmental (including sound 
speed profiles, bathymetry, and sediment characteristics at a minimum) 
parameters, (2) a comprehensive source model (i.e., Gundalf Optimizer) 
and (3) an appropriate sound propagation model (i.e., BELLHOP). 
Specifically, the Commission reiterates that LDEO should be using the 
ray-tracing propagation model BELLHOP--which is a free, standard 
propagation code that readily incorporates all environmental inputs 
listed herein, rather than the

[[Page 60061]]

limited, in-house MATLAB code currently in use, and recommends NMFS 
specify why it believes that LDEO's modeling approaches provide more 
accurate, realistic, and appropriate Level A and Level B harassment 
zones than BELLHOP. The Commission recommends that NMFS (1) specify why 
it believes that LDEO's model and other `modeling' approaches provide 
more accurate, realistic, and appropriate Level A and B harassment 
zones than BELLHOP and (2) explain, if LDEO's model and other 
`modeling' approaches are considered best available science, why other 
action proponents that conduct seismic surveys are not implementing 
similar methods particularly given their simplicity.
    Response: We appreciate the Commission's input and direct the 
reader to our recent response to the same comment, which can be found 
in the final authorization for similar SIO activities in Argentina (84 
FR 54849; October 11, 2019).
    Comment: The Commission recommends that, in the next six months, 
NMFS develop a policy regarding how uncertainty should be incorporated 
in density estimates that have been extrapolated from other areas and 
other seasons and specify what adjustments (i.e., CVs, standard 
deviations, blanket correction factors) should be used for NSF-funded 
and -affiliated surveys.
    Response: NMFS appreciates and thanks the Commission's for its 
recommendation and will take it under consideration.
    Comment: The Commission noted that monitoring and reporting 
requirements adopted need to be sufficient to provide a reasonably 
accurate assessment of the manner of taking and the numbers of animals 
taken incidental to the specified activity. Those assessments should 
account for all animals in the various survey areas, including those 
animals directly on the trackline that are not detected and how well 
animals are detected based on the distance from the observer which is 
achieved by incorporating g(0) and f(0) values. The Commission 
recommended that NMFS require SIO to use the Commission's method as 
described in the Commission's Addendum to its May 1, 2019 letter to 
better estimate the numbers of marine mammals taken by Level B 
harassment for the incidental harassment authorization. The Commission 
stated that all other NSF-affiliated entities and all seismic operators 
should use this method as well.
    Response: We thank the Commission for their recommendation. NMFS is 
in the process of determining the appropriate method for deriving post-
survey estimates of the total number of animals taken by activities 
such as Scripps' marine geophysical survey.
    Comment: The Commission recommended NMFS require SIO to specify in 
the final monitoring report (1) the number of days the survey occurs 
and the array is active and (2) the percentage of time and total time 
the array is active during daylight vs nighttime hours (including dawn 
and dusk).
    Response: NMFS will require SIO to include this information in 
their final monitoring report.
    Comment: The Commission recommended that NMFS refrain from using 
the renewal process for SIO's authorization based on the complexity of 
analysis and potential for impacts on marine mammals, and the potential 
burden on reviewers of reviewing key documents and developing comments 
quickly. Additionally, the Commission recommends that NMFS use the IHA 
renewal process sparingly and selectively for activities expected to 
have the lowest levels of impacts to marine mammals and that require 
less complex analysis.
    Response: We appreciate the Commission's input and direct the 
reader to our recent response to the same comment, which can be found 
at 84 FR 52464 (October 2, 2019), pg. 52466. If and when SIO requests a 
Renewal, we will consider the Commission's comment further and address 
the concerns specific to this project. We will consider this comment 
further when and if SIO requests a renewal.
    Comment: The Commission noted that the planned surveys are 
scheduled to three days after the public comment period closes and 
expressed concern that NMFS did not have adequate time to consider 
public comments before issuing the IHA. The Commission recommended NMFS 
more thoroughly review applications, draft Federal Register notices, 
and draft proposed authorizations prior to submitting any proposed 
authorizations to the Federal Register, as well as require earlier 
submission of applications and other documentation to ensure sufficient 
time to prepare the proposed authorization and consider comments 
received from the public. In addition, Commission recommends that NMFS 
require NSF-funded and -affiliated applications and other documentation 
to be submitted at least eight months in advance of the vessel leaving 
port so that NMFS has sufficient time to review and provide comments on 
the adequacy and accuracy of the application, allow action proponents 
to make necessary revisions or additions to the application, draft its 
proposed authorization, and consider the comments received from the 
public.
    Response: We appreciate the Commission's input and direct the 
reader to our recent response to the same comment, which can be found 
in the final authorization for similar SIO activities in Argentina (84 
FR 54849; October 11, 2019).

Changes From Proposed to Final IHA

    Minor corrections have been made to the estimated take table (see 
Table 9). As described in the Comments and Response section, calculated 
Level A harassment takes were added to Authorized Level B harassment 
takes (to ensure the correct total takes) for six species. In addition, 
group sizes were adjusted for three species based on Di Tullio et al. 
(2016) and therefore changes were made to the authorized take by Level 
B harassment for those species.

Description of Marine Mammals in the Area of Specified Activities

    Section 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS's website (https://www.fisheries.noaa.gov/find-species).
    The populations of marine mammals considered in this document do 
not occur within the U.S. 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 proxy sources including International Whaling Commission 
population estimates (IWC 2019), the U.S. Atlantic SARs (Hayes et al., 
2018) for a few dolphin species, and various literature estimates (see 
IHA application for further detail), as this is considered the best 
available information on

[[Page 60062]]

potential abundance of marine mammals in the area. However, as 
described above, the marine mammals encountered by the planned survey 
are not assigned to stocks. All abundance estimate values presented in 
Table 1 are the most recent available at the time of publication and 
are available in the 2018 U.S. Atlantic SARs (e.g., Hayes et al. 2018) 
available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments, except where noted 
otherwise.
    Table 1 lists all species with expected potential for occurrence in 
the Argentine Basin, Southwest Atlantic Ocean, and summarizes 
information related to the population, including regulatory status 
under the MMPA and ESA. For taxonomy, we follow Committee on Taxonomy 
(2018).

               Table 1--Marine Mammal Species Potentially Present in the Project Area Expected To Be Affected by the Specified Activities
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                                                                               ESA/MMPA
                                                                                status;                                                    Relative
           Common name              Scientific name         Stock \1\        strategic (Y/       Abundance               PBR             occurrence in
                                                                                N) \2\                                                   project area
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                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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                                                                    Family Balaenidae
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Southern right whale............  Eubalaena australis  n/a................  E/D; N          12,000 \3\.........  N.A................  Uncommon.
                                                                                            3,300\5\...........
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                                                                  Family Cetotheriidae
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Pygmy right whale...............  Caperea marginata..  n/a................  ..............  N.A................  N.A................  Rare.
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                                                            Family Balaenopteridae (rorquals)
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Blue whale......................  Balaenoptera         n/a................  E/D; Y          2,300 true \4\.....  N.A................  Rare.
                                   musculus.                                                1,500 pygmy \6\....
Fin whale.......................  Balaenoptera         n/a................  E/D; Y          15,000 \6\.........  N.A................  Uncommon.
                                   physalus.
Sei whale.......................  Balaenoptera         n/a................  E               10,000 \6\.........  N.A................  Uncommon.
                                   borealis.
Common minke whale..............  Balaenoptera         n/a................  ..............  515,000 3 6........  N.A................  Common.
                                   acutorostrata.
Antarctic minke whale...........  Balaenoptera         n/a................  ..............  515,000 3 6........  N.A................  Common.
                                   bonaerensis.
Humpback whale..................  Megaptera            n/a................  ..............  42,000 \3\.........  N.A................  Rare.
                                   novaeangliae.
Bryde's whale...................  Balaenoptera edeni/  n/a................  ..............  48,109 \7\.........  N.A................  Common.
                                   brydei.
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                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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                                                                   Family Physeteridae
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Sperm whale.....................  Physeter             n/a................  E               12,069 \10\........  N.A................  Uncommon.
                                   macrocephalus.
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                                                                     Family Kogiidae
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Pygmy sperm whale...............  Kogia breviceps....  n/a................  ..............  N.A................  N.A................  Rare.
Dwarf sperm whale...............  Kogia sima.........  n/a................  ..............  N.A................  N.A................  Uncommon.
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                                                            Family Ziphiidae (beaked whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Arnoux's beaked whale...........  Berardius arnuxii..  n/a................  ..............  599,300 \11\.......  N.A................  Uncommon.
Cuvier's beaked whale...........  Ziphius cavirostris  n/a................  ..............  599,300 \11\.......  N.A................  Uncommon.
Southern bottlenose whale.......  Hyperoodon           n/a................  ..............  599,300 \11\.......  N.A................  Uncommon.
                                   planifrons.
Shepherd's beaked whale.........  Tasmacetus sheperdi  n/a................  ..............  N.A................  N.A................  Uncommon.
Blainville's beaked whale.......  Mesoplodon           n/a................  ..............  N.A................  N.A................  Rare.
                                   densirostris.
Gray's beaked whale.............  Mesoplodon grayi...  n/a................  ..............  599,300 \11\.......  N.A................  Uncommon.
Gervais' beaked whale...........  Mesoplodon           n/a................  ..............  N.A................  N.A................  Rare.
                                   europaeus.
Hector's beaked whale...........  Mesoplodon hectori.  n/a................  ..............  N.A................  N.A................  Rare.
True's beaked whale.............  Mesoplodon mirus...  n/a................  ..............  N.A................  N.A................  Rare.
Strap-toothed beaked whale......  Mesoplodon layardii  n/a................  ..............  599,300 \11\.......  N.A................  Uncommon.
Andrews' beaked whale...........  Mesoplodon bowdoini  n/a................  ..............  N.A................  N.A................  Rare.
Spade-toothed beaked whale......  Mesoplodon           n/a................  ..............  N.A................  N.A................  Rare.
                                   traversii.
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                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Risso's dolphin.................  Grampus griseus....  n/a................  ..............  18,250 \12\........  N.A................  Common.
Rough-toothed dolphin...........  Steno bredanensis..  n/a................  ..............  N.A................  N.A................  Common.
Common bottlenose dolphin.......  Tursiops truncatus.  n/a................  ..............  77,532 \12\........  N.A................  Uncommon.
Pantropical spotted dolphin.....  Stenella attenuata.  n/a................  ..............  3,333 \12\.........  N.A................  Common.
Atlantic spotted dolphin........  Stenella frontalis.  n/a................  ..............  44,715 \12\........  N.A................  Rare.
Spinner dolphin.................  Stenella             n/a................  ..............  N.A................  N.A................  Uncommon.
                                   longirostris.
Clymene dolphin.................  Stenella clymene...  n/a................  ..............  N.A................  N.A................  Rare.
Striped dolphin.................  Stenella             n/a................  ..............  54,807 \12\........  N.A................  Uncommon.
                                   coeruleoalba.
Short-beaked common dolphin.....  Delphinus delphis..  n/a................  ..............  70,184 \10\........  N.A................  Uncommon.
Fraser's dolphin................  Lagenodelphis hosei  n/a................  ..............  N.A................  N.A................  Uncommon.
Dusky dolphin...................  Lagenorhynchus       n/a................  ..............  7,252 \12\.........  N.A................  Rare.
                                   obscurus.
Hourglass dolphin...............  Lagenorhynchus       n/a................  ..............  150,000 \6\........  N.A................  Rare.
                                   cruciger.
Southern right whale dolphin....  Lissodelphis         n/a................  ..............  N.A................  N.A................  Uncommon.
                                   peronii.
Killer whale....................  Orcinus orca.......  n/a................  ..............  25,000 \14\........  N.A................  Uncommon.
Short-finned pilot whale........  Globicephala         n/a................  ..............  200,000 \6\........  N.A................  Uncommon.
                                   macrorhynchus.
Long-finned pilot whale.........  Globicephala melas.  n/a................  ..............  200,000 \6\........  N.A................  Uncommon.
False killer whale..............  Pseudorca            n/a................  ..............  N.A................  N.A................  Uncommon.
                                   crassidens.

[[Page 60063]]

 
Pygmy killer whale..............  Feresa attenuata...  n/a................  ..............  N.A................  N.A................  Uncommon.
Melon-headed whale..............  Peponocephala        n/a................  ..............  N.A................  N.A................  Uncommon.
                                   electra.
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                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cape fur seal...................  Arctocephalus        n/a................  ..............  Approximately 2      N.A................  Uncommon.
                                   pusillus pusillus.                                        million \16\.
Subantarctic fur seal...........  Arctocephalus        n/a................  ..............  400,000 \15\.......  N.A................  Uncommon.
                                   tropicalis.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crabeater seal..................  Lobodon              n/a................  ..............  5--10 million \17\.  N.A................  Rare.
                                   carcinophaga.
Leopard seal....................  Hydrurga leptonyx..  n/a................  ..............  222,000--440,000     N.A................  Rare.
                                                                                             \18\.
Southern elephant seal..........  Mirounga leonina...  n/a................  ..............  750,000 \19\.......  N.A................  Uncommon.
--------------------------------------------------------------------------------------------------------------------------------------------------------
N.A. = Data not available. NL = Not listed.
\1\ U.S. Endangered Species Act (NOAA 2019): EN = Endangered.
\2\ International Union for the Conservation of Nature (IUCN) Red List of Threatened Species (IUCN 2019): EN = Endangered; NT = Near Threatened; VU =
  Vulnerable; LC = Least Concern; DD = Data Deficient
\3\ Convention on International Trade in Endangered Species of Wild Fauna and Flora (UNEP-WCMC 2017): Appendix I = Threatened with extinction; Appendix
  II = not necessarily threatened with extinction but may become so unless trade is closely controlled.
\4\ Southern Hemisphere (IWC 2019).
\5\ Southwest Atlantic (IWC 2019).
\6\ Antarctic (Boyd 2002).
\7\ Southern Hemisphere (IWC 1981).
\8\ Dwarf and Antarctic minke whales combined.
\9\ There are 14 distinct population segments (DPSs) of humpback whales recognized under the ESA; the Brazil and Gabon/Southwest Africa DPSs are not
  listed (NOAA 2019).
\10\ Estimate for the Antarctic, south of 60[deg]S (Whitehead 2002).
\11\ All beaked whales south of the Antarctic Convergence; mostly southern bottlenose whales (Kasamatsu and Joyce 1995).
\12\ Estimate for the western North Atlantic (Hayes et al. 2018).
\13\ Estimate for Patagonian coast (Dans et al. 1997).
\14\ Minimum estimate for Southern Ocean (Branch and Butterworth 2001).
\15\ Global population (Hofmeyr and Bester 2018).
\16\ Butterworth et al. (1995 in Kirkman and Arnould 2018).
\17\ Global population (Bengtson and Stewart 2018).
\18\ Global population (Rogers 2018).
\19\ Total world population (Hindell et al. 2016).

    All species that could potentially occur in the planned survey 
areas are included in Table 1. As described below, all 48 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 
planned geophysical surveys, including brief introductions to the 
species and relevant stocks as well as available information regarding 
population trends and threats, information regarding local occurrence, 
and marine mammal hearing were provided in the Federal Register notice 
for the proposed IHA (84 FR 51886; September 30, 2019). 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 NMFS's website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects from underwater noise from SIO's planned geophysical 
surveys have the potential to result in harassment of marine mammals in 
the vicinity of the action area. The Federal Register notice for the 
proposed IHA (84 FR 51886; September 30, 2019) included a discussion of 
the effects of anthropogenic noise on marine mammals and their habitat, 
therefore that information is not repeated here; please refer to that 
Federal Register notice (84 FR 51886; September 30, 2019) for that 
information. No instances of serious injury or mortality are expected 
as a result of the planned activities.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would be by Level B harassment only, as use of the 
acoustic sources (i.e., seismic airgun) has the potential to result in 
disruption of behavioral patterns for individual marine mammals. Based 
on the nature of the activity and the anticipated effectiveness of the 
mitigation measures (i.e., marine mammal exclusion zones) discussed in 
detail below in Mitigation section, Level A harassment is neither 
anticipated nor authorized. As described previously, no mortality is 
anticipated or authorized for this activity. Below we describe how the 
take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds

[[Page 60064]]

above which NMFS believes the best available science indicates marine 
mammals will be behaviorally harassed or incur some degree of permanent 
hearing impairment; (2) the area or volume of water that will be 
ensonified above these levels in a day; (3) the density or occurrence 
of marine mammals within these ensonified areas; and, (4) and the 
number of days of activities. We note that while these basic factors 
can contribute to a basic calculation to provide an initial prediction 
of takes, additional information that can qualitatively inform take 
estimates is also sometimes available (e.g., previous monitoring 
results or average group size). Below, we describe the factors 
considered here in more detail and present the authorized take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007; 
Ellison et al., 2012). Based on what the available science indicates, 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources.
    SIO's planned activity includes the use of impulsive seismic 
sources, and therefore the 160 dB re 1 [mu]Pa (rms) is applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance) (NMFS, 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). SIO's planned activity includes the use 
of impulsive seismic sources.
    These thresholds are provided in Table 2 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS Onset acoustic thresholds * (received level)
----------------------------------------------------------------------------------------------------------------
             Hearing group                        Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE, LF,24h: 199 dB
                                          LE, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB    Cell 4: LE, MF,24h: 198 dB
                                          LE, MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB    Cell 6: LE, HF,24h: 173 dB
                                          LE, HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB    Cell 8: LE,PW,24h: 201 dB
                                          LE, PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB    Cell 10: LE,OW,24h: 219 dB
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The planned survey would entail the use of a 2-airgun array with a 
total discharge of 90 in\3\ at a two depth of 2-4 m. Lamont-Doherty 
Earth Observatory (LDEO) model results are used to determine the 160 
dBrms radius for the 2-airgun array in deep water (>1,000 m) 
down to a maximum water depth of 2,000 m. Received sound levels were 
predicted by LDEO's model (Diebold et al., 2010) as a function of 
distance from the airguns, for the two 45 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 60065]]

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, comparisons at short ranges 
between sound levels for direct arrivals recorded by the calibration 
hydrophone and model results for the same array tow depth are in good 
agreement (see Figures 12 and 14 in Appendix H of NSF-USGS 2011). 
Consequently, isopleths falling within this domain can be predicted 
reliably by the LDEO model, although they may be imperfectly sampled by 
measurements recorded at a single depth. At greater distances, the 
calibration data show that seafloor-reflected and sub-seafloor-
refracted arrivals dominate, whereas the direct arrivals become weak 
and/or incoherent. Aside from local topography effects, the region 
around the critical distance is where the observed levels rise closest 
to the model curve. However, the observed sound levels are found to 
fall almost entirely below the model curve. Thus, analysis of the Gulf 
of Mexico calibration measurements demonstrates that although simple, 
the LDEO model is a robust tool for conservatively estimating 
isopleths.
    The planned surveys would acquire data with two 45-in\3\ guns at a 
tow depth of 2-4 m. For deep water (>1,000 m), we use the deep-water 
radii obtained from LDEO model results down to a maximum water depth of 
2,000 m for the airgun array with 2-m and 8-m airgun separation. 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).
    LDEO's modeling methodology is described in greater detail in SIO's 
IHA application. The estimated distances to the Level B harassment 
isopleths for the two planned airgun configurations in each water depth 
category are shown in Table 3.

 Table 3--Predicted Radial Distances From R/V Thompson Seismic Source to
         Isopleths Corresponding to Level B Harassment Threshold
------------------------------------------------------------------------
                                                            Predicted
                                                        distances (m) to
       Airgun configuration          Water depth (m)     160 dB received
                                                           sound level
------------------------------------------------------------------------
Two 45 in\3\ guns, 2-m separation  >1,000 (deep)......           \a\ 539
                                   100-1,000                     \b\ 809
                                    (intermediate).
Two 45 in\3\ guns, 8-m separation  > 1,000 (deep).....           \a\ 578
                                   100-1,000                     \b\ 867
                                    (intermediate).
------------------------------------------------------------------------
\a\ Distance based on LDEO model results.
\b\ Distance based on LDEO model results with a 1.5 x correction factor
  between deep and intermediate water depths.
\c\ Distance based on empirically derived measurements in the Gulf of
  Mexico with scaling applied to account for differences in tow depth.

    Predicted distances to Level A harassment isopleths, which vary 
based on marine mammal hearing groups, were calculated based on 
modeling performed by LDEO using the NUCLEUS software program and the 
NMFS User Spreadsheet, described below. The updated acoustic thresholds 
for impulsive sounds (e.g., airguns) contained in the Technical 
Guidance were presented as dual metric acoustic thresholds using both 
SELcum and peak sound pressure metrics (NMFS 2018). As dual 
metrics, NMFS considers onset of PTS (Level A harassment) to have 
occurred when either one of the two metrics is exceeded (i.e., metric 
resulting in the largest isopleth). The SELcum metric 
considers both level and duration of exposure, as well as auditory 
weighting functions by marine mammal hearing group. In recognition of 
the fact that the requirement to calculate Level A harassment 
ensonified areas could be more technically challenging to predict due 
to the duration component and the use of weighting functions in the new 
SELcum thresholds, NMFS developed an optional User 
Spreadsheet that includes tools to help predict a simple isopleth that 
can be used in conjunction with marine mammal density or occurrence to 
facilitate the estimation of take numbers.
    The SELcum for the 2-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 
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 we use this method for consistency 
across all array sizes.
    SIO used the same acoustic modeling as Level B harassment with a 
small grid step in both the inline and depth

[[Page 60066]]

directions to estimate the SELcum and peak SPL. The 
propagation modeling takes into account all airgun interactions at 
short distances from the source including interactions between 
subarrays using the NUCLEUS software to estimate the notional signature 
and the MATLAB software to calculate the pressure signal at each mesh 
point of a grid. For a more complete explanation of this modeling 
approach, please see Appendix A: Determination of Mitigation Zones in 
SIO's IHA application.

                   Table 4--Modeled Source Levels (dB) for R/V Thompson 90 in\3\ Airgun Arrays
----------------------------------------------------------------------------------------------------------------
                                                    8-kn survey     8-kn survey     5-kn survey     5-kn survey
                                                     with 8-m        with 8-m        with 2-m        with 2-m
            Functional hearing group                  airgun          airgun          airgun          airgun
                                                    separation:     separation:     separation:     separation:
                                                   Peak SPLflat       SELcum       Peak SPLflat       SELcum
----------------------------------------------------------------------------------------------------------------
Low frequency cetaceans (Lpk,flat: 219 dB;                 228.8             207           232.8           206.7
 LE,LF,24h: 183 dB).............................
Mid frequency cetaceans (Lpk,flat: 230 dB;               \1\ N/A           206.7           229.8           206.9
 LE,MF,24h: 185 dB).............................
High frequency cetaceans (Lpk,flat: 202 dB;                  233           207.6           232.9           207.2
 LE,HF,24h: 155 dB).............................
Phocid Pinnipeds (Underwater) (Lpk,flat: 218 dB;             230           206.7           232.8           206.9
 LE,HF,24h: 185 dB).............................
Otariid Pinnipeds (Underwater) (Lpk,flat: 232            \1\ N/A             203           225.6           207.4
 dB; LE,HF,24h: 203 dB).........................
----------------------------------------------------------------------------------------------------------------
\1\ N/A indicates source level not applicable or not available. There are no values for the 2 x 45 cu.in at 4m
  depth with an 8m separation for the MF cetaceans and Otariids (maximum peak value is 221dB so less than 230 or
  232dB). Therefore, we cannot provide any radial distance or modified peak farfield values for these two
  hearing groups.

    In order to more realistically incorporate the Technical Guidance's 
weighting functions over the seismic array's full acoustic band, 
unweighted spectrum data for the Thompson's airgun array (modeled in 1 
Hz bands) was used to make adjustments (dB) to the unweighted spectrum 
levels, by frequency, according to the weighting functions for each 
relevant marine mammal hearing group. These adjusted/weighted spectrum 
levels were then converted to pressures ([mu]Pa) in order to integrate 
them over the entire broadband spectrum, resulting in broadband 
weighted source levels by hearing group that could be directly 
incorporated within the User Spreadsheet (i.e., to override the 
Spreadsheet's more simple weighting factor adjustment). Using the User 
Spreadsheet's ``safe distance'' methodology for mobile sources 
(described by Sivle et al., 2014) with the hearing group-specific 
weighted source levels, and inputs assuming spherical spreading 
propagation and source velocities and shot intervals provided in SIO's 
IHA application, potential radial distances to auditory injury zones 
were calculated for SELcum thresholds, for both array 
configurations.
    Inputs to the User Spreadsheet in the form of estimated SLs are 
shown in Table 4. User Spreadsheets used by SIO to estimate distances 
to Level A harassment isopleths for the two potential airgun array 
configurations are shown in Tables A-4 and A-5 in Appendix A of SIO's 
IHA application. Outputs from the User Spreadsheet in the form of 
estimated distances to Level A harassment isopleths are shown in Table 
5. As described above, NMFS considers onset of PTS (Level A harassment) 
to have occurred when either one of the dual metrics (SELcum 
or Peak SPLflat) is exceeded (i.e., metric resulting in the 
largest isopleth).

          Table 5--Modeled Radial Distances to Isopleths Corresponding to Level A Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
                                                    8-kn survey     8-kn survey     5-kn survey     5-kn survey
                                                     with 8-m        with 8-m        with 2-m        with 2-m
  Functional Hearing Group (Level A harassment        airgun          airgun          airgun          airgun
                   thresholds)                      separation:     separation:     separation:     separation:
                                                   Peak SPLflat       SELcum       Peak SPLflat       SELcum
----------------------------------------------------------------------------------------------------------------
Low frequency cetaceans (Lpk,flat: 219 dB;                  3.08             2.4            4.89             6.5
 LE,LF,24h: 183 dB).............................
Mid frequency cetaceans (Lpk,flat: 230 dB;                     0               0            0.98               0
 LE,MF,24h: 185 dB).............................
High frequency cetaceans (Lpk,flat: 202 dB;                34.84               0           34.62               0
 LE,HF,24h: 155 dB).............................
Phocid Pinnipeds (Underwater) (Lpk,flat: 218 dB;            4.02               0            5.51             0.1
 LE,HF,24h: 185 dB).............................
Otariid Pinnipeds (Underwater) (Lpk,flat: 232                  0               0            0.48               0
 dB; LE,HF,24h: 203 dB).........................
----------------------------------------------------------------------------------------------------------------

    Note that because of some of the assumptions included in the 
methods used, isopleths produced may be overestimates to some degree, 
which will ultimately result in some degree of overestimate of take by 
Level A harassment. However, these tools offer the best way to predict 
appropriate isopleths when more sophisticated 3D modeling methods are 
not available, and NMFS continues to develop ways to quantitatively 
refine these tools and will qualitatively address the output where 
appropriate. For mobile sources, such as the planned seismic survey, 
the User Spreadsheet predicts the closest distance at which a 
stationary animal would not incur PTS if the sound source traveled by 
the animal in a straight line at a constant speed.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    SIO determined that the preferred source of density data for marine 
mammal species that might be encountered in the planned survey areas in 
the South Atlantic Ocean was Di Tullio et al. (2016). The rationale for 
using these data was that these surveys were conducted offshore along 
the continental slope at the same latitudes as the planned seismic 
surveys and so come from a similar season, water depth category, and 
climatic region in the southern Atlantic Ocean. When data for species 
expected to occur in the planned seismic survey areas were not 
available in Di Tullio et al. (2016), data from White et al. (2002) was 
used as

[[Page 60067]]

calculated in LGL/NSF (2019) because they came from an area which was 
slightly south of the planned project area but well north of the AECOM/
NSF (2014) study area. An exception was made for the southern right 
whale, for which densities from AECOM/NSF (2014) were higher and thus 
more conservative. Next data came from AECOM/NSF (2014); although they 
come from an area south of the planned project area, they were the next 
best data available for those species. For species not included in 
these sources stated above, data came from from de Boer (2010), Garaffo 
et al. (2011), NOAA-SWFSC LOA (2013 in AECOM/NSF 2014), Wedekin et al. 
(2014), Bradford et al. (2017), and Mannocci et al. (2017). When 
densities were not directly available from the above studies, they were 
estimated using sightings and effort reported in those sources. 
Densities calculated from de Boer (2010) come from LGL/NSF (2016); 
densities from White et al. (2002), Garaffo et al. (2011), and Wedekin 
et al. (2014) are from LGL/NSF (2019). Data sources and density 
calculations are described in detail in Appendix B of SIO's IHA 
application. For some species, the densities derived from past surveys 
may not be representative of the densities that would be encountered 
during the planned seismic surveys. However, the approach used is based 
on the best available data. Estimated densities used to inform take 
estimates are presented in Table 6.

       Table 6--Marine Mammal Densities in the Planned Survey Area
------------------------------------------------------------------------
                                                             Estimated
                         Species                            density (#/
                                                            km\2\) \a\
------------------------------------------------------------------------
                              LF Cetaceans
------------------------------------------------------------------------
Southern right whale....................................        0.007965
Pygmy right whale.......................................            N.A.
Blue whale..............................................        0.000051
Fin whale...............................................        0.000356
Sei whale...............................................        0.000086
Bryde's whale...........................................        0.000439
Common (dwarf) minke whale..............................        0.077896
Antarctic minke whale...................................        0.077896
Humpback whale..........................................        0.000310
------------------------------------------------------------------------
                              MF Cetaceans
------------------------------------------------------------------------
Sperm whale.............................................        0.005975
Arnoux's beaked whale...................................        0.011379
Cuvier's beaked whale...................................        0.000548
Southern bottlenose whale...............................        0.007906
Shepherd's beaked whale.................................        0.009269
Blainville's beaked whale...............................        0.000053
Gray's beaked whale.....................................        0.001885
Hector's beaked whale...................................        0.000212
Gervais' beaked whale...................................        0.001323
True's beaked whale.....................................        0.000053
Strap-toothed beaked whale..............................        0.000582
Andrew's beaked whale...................................        0.000159
Spade-toothed beaked whale..............................        0.000053
Risso's dolphin.........................................        0.010657
Rough-toothed dolphin...................................        0.005954
Common bottlenose dolphin...............................        0.040308
Pantropical spotted dolphin.............................        0.003767
Atlantic spotted dolphin................................        0.213721
Spinner dolphin.........................................        0.040720
Clymene dolphin.........................................        0.006800
Striped dolphin.........................................        0.004089
Short-beaked common dolphin.............................        0.717166
Fraser's dolphin........................................        0.021040
Dusky dolphin...........................................        0.012867
Southern right whale dolphin............................        0.006827
Killer whale............................................        0.000266
Short-finned pilot whale................................        0.002085
Long-finned pilot whale.................................        0.021379
False killer whale......................................        0.000882
Pygmy killer whale......................................        0.000321
Melon-headed whale......................................        0.003540
------------------------------------------------------------------------
                              HF Cetaceans
------------------------------------------------------------------------
Pygmy sperm whale.......................................        0.003418
Dwarf sperm whale.......................................        0.002582
Hourglass dolphin.......................................        0.011122
------------------------------------------------------------------------
                                Otariids
------------------------------------------------------------------------
Subantarctic fur seal...................................         0.00274
Cape fur seal...........................................            N.A.
------------------------------------------------------------------------
                                 Phocids
------------------------------------------------------------------------
Crabeater seal..........................................         0.00649
Leopard seal............................................         0.00162
Southern elephant seal..................................         0.00155
------------------------------------------------------------------------
N.A. indicates density estimate is not available.
Species in italics are listed under the ESA as endangered.
\a\ See Appendix B in SIO's IHA application for density sources.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. In order to estimate 
the number of marine mammals predicted to be exposed to sound levels 
that would result in Level A harassment or Level B harassment, radial 
distances from the airgun array to predicted isopleths corresponding to 
the Level A harassment and Level B harassment thresholds are 
calculated, as described above. Those radial distances are then used to 
calculate the area(s) around the airgun array predicted to be 
ensonified to sound levels that exceed the Level A harassment and Level 
B harassment thresholds. The area estimated to be ensonified in a 
single day of the survey is then calculated (Table 7), based on the 
areas predicted to be ensonified around the array and the estimated 
trackline distance traveled per day. This number is then multiplied by 
the number of survey days. The product is then multiplied by 1.25 to 
account for the additional 25 percent contingency. This results in an 
estimate of the total area (km\2\) expected to be ensonified to the 
Level A and Level B harassment thresholds for each survey type (Table 
7).

                                  Table 7--Areas (km\2\) To Be Ensonified to Level A and Level B Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Daily                                           Total
                Survey type                           Criteria               Relevant       ensonified     Total survey     25 percent      ensonified
                                                                           isopleth  (m)   area (km\2\)        days          increase      area  (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
5-kn survey...............................                                           Level B Harassment (160 dB)
                                           -------------------------------------------------------------------------------------------------------------
                                            Intermediate water..........             809           14.67              10            1.25          183.34
                                            Deep water..................             539          231.31              10            1.25         2891.42
                                           -------------------------------------------------------------------------------------------------------------
                                                                                         Level A Harassment
                                           -------------------------------------------------------------------------------------------------------------
                                            LF cetacean.................             6.5            2.89              10            1.25          36.125
                                            MF cetacean.................               1            0.44              10            1.25            5.55
                                            HF cetacean.................            34.6           15.37              10            1.25          192.13

[[Page 60068]]

 
                                            Phocids.....................             5.5            2.44              10            1.25           30.53
                                            Otariids....................             0.5            0.22              10            1.25            2.77
                                           -------------------------------------------------------------------------------------------------------------
8-kn survey...............................                                           Level B Harassment (160 dB)
                                           -------------------------------------------------------------------------------------------------------------
                                            Intermediate water..........             867           25.95               4            1.25          129.75
                                            Deep water..................             578          395.88               4            1.25         1979.38
                                           -------------------------------------------------------------------------------------------------------------
                                                                                         Level A Harassment
                                           -------------------------------------------------------------------------------------------------------------
                                            LF cetacean.................             3.1            2.21               4            1.25           11.04
                                            MF cetacean.................               0               0               4            1.25               0
                                            HF cetacean.................            34.8           24.78               4            1.25             124
                                            Phocids.....................               4            2.85               4            1.25           14.24
                                            Otariids....................               0               0               4            1.25               0
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The total ensonified areas (km\2\) for each criteria presented in 
Table 7 were summed to determine the total ensonified area for all 
survey activities (Table 8).

         Table 8--Total Ensonified Areas (km\2\) for All Surveys
------------------------------------------------------------------------
                                                               Total
                                                            ensonified
                        Criteria                           area (km\2\)
                                                             for  all
                                                              surveys
------------------------------------------------------------------------
160 dB Level B (all depths).............................         5183.89
160 dB Level B (intermediate water).....................          313.09
160 dB Level B (deep water).............................         4870.80
LF cetacean Level A.....................................           47.11
MF cetacean Level A.....................................            5.55
HF cetacean Level A.....................................          316.04
Phocids Level A.........................................           44.77
Otariids Level A........................................            2.77
------------------------------------------------------------------------

    The marine mammals predicted to occur within these respective 
areas, based on estimated densities (Table 6), are assumed to be 
incidentally taken. While some takes by Level A harassment have been 
estimated, based on the nature of the activity and in consideration of 
the planned mitigation measures (see Mitigation section below), Level A 
take is not expected to occur and has not been authorized. Estimated 
exposures for the planned survey are shown in Table 9.

     Table 9--Calculated and Authorized Level A and Level B Exposures, and Percentage of Population Exposed
----------------------------------------------------------------------------------------------------------------
                                                        Calculated take \1\         Authorized
                                                 --------------------------------    take \4\
                                                                                 ----------------   Percent of
                     Species                          Level B         Level A         Level B     population \5\
                                                  harassment \2\  harassment \3\    harassment
                                                                                       only
----------------------------------------------------------------------------------------------------------------
LF Cetaceans:
    Southern right whale........................              41               0              41             1.3
    Pygmy right whale...........................            N.A.            N.A.           \5\ 2            N.A.
    Blue whale..................................               0               0             3 6            <0.1
    Fin whale...................................               2               0              46            <0.1
    Sei whale...................................               0               0             3 6            <0.1
    Bryde's whale...............................               2               0            20 5            <0.1
    Common (dwarf) minke whale..................             400               4             404            <0.1
    Antarctic minke whale.......................             400               4             404            <0.1
    Humpback whale..............................               2               0            2035               0
MF Cetaceans:
    Sperm whale.................................              31               0              31             0.3
    Arnoux's beaked whale.......................              59               0              59            <0.1
    Cuvier's beaked whale.......................               3               0               3            <0.1
    Southern bottlenose whale...................              41               0              41            <0.1
    Shepherd's beaked whale.....................              48               0              48            N.A.
    Blainville's beaked whale...................               0               0             7 6            N.A.
    Gray's beaked whale.........................              10               0              10            <0.1
    Hector's beaked whale.......................               1               0             2 6            N.A.
    Gervais' beaked whale.......................               7               0               7            N.A.
    True's beaked whale.........................               0               0             2 6            N.A.
    Strap-toothed beaked whale..................               3               0               3            <0.1
    Andrew's beaked whale.......................               1               0             2 6            N.A.
    Spade-toothed beaked whale..................               0               0             2 6            N.A.

[[Page 60069]]

 
    Risso's dolphin.............................              55               0            78 6             0.3
    Rough-toothed dolphin.......................              31               0            55 6            N.A.
    Common bottlenose dolphin...................             209               0             209             0.3
    Pantropical spotted dolphin.................              20               0           104 6             0.6
    Atlantic spotted dolphin....................            1108               0            1108             2.5
    Spinner dolphin.............................             211               0           315 6            N.A.
    Clymene dolphin.............................              35               0           122 6            N.A.
    Striped dolphin.............................              21               0           110 5            <0.1
    Short-beaked common dolphin.................            3714               4            3718             5.3
    Fraser's dolphin............................             109               0           283 6            N.A.
    Dusky dolphin...............................              67               0              67             0.9
    Southern right whale dolphin................              35               0              35            N.A.
    Killer whale................................               1               0             8 6            <0.1
    Short-finned pilot whale....................              11               0            41 6            <0.1
    Long-finned pilot whale.....................             111               0             111             0.1
    False killer whale..........................               5               0            35 6            N.A.
    Pygmy killer whale..........................               2               0            26 6            N.A.
    Melon-headed whale..........................              18               0           170 6            N.A.
HF Cetaceans:
    Pygmy sperm whale...........................              17               1              18            N.A.
    Dwarf sperm whale...........................              12               1              13            N.A.
    Hourglass dolphin...........................              54               4              58            <0.1
Otariids:
    Subantarctic fur seal.......................              14               0              14            <0.1
    Cape fur seal...............................            N.A.            N.A.            20 7            N.A.
Phocids:
    Crabeater seal..............................              34               0              34            <0.1
    Leopard seal................................               8               0               8            <0.1
    Southern elephant seal......................               8               0               8            <0.1
----------------------------------------------------------------------------------------------------------------
Species in italics are listed under the ESA as endangered. N.A. (-) is not available.
\1\ Take using NMFS daily method for calculating ensonified area: Estimated density multiplied by the daily
  ensonified area to levels >=160 dB re 1 [micro]Parms on one selected day multiplied by the number of survey
  days, times 1.25 (see Appendix C); daily ensonified area = full 160-dB area minus ensonified area for the
  appropriate PTS threshold.
\2\ Level B harassment takes, based on the 160-dB criterion, excluding exposures to sound levels equivalent to
  PTS thresholds.
\3\ Level A harassment takes if there were no mitigation measures.
\4\ Authorized take by Level B harassment are the Level B harassment calculated takes, unless otherwise
  indicated. For those species where Level A harassment takes were calculated, those takes were added to the
  Authorized Level B harassment takes. Level A harassment is unlikely due to size of the calculated PTS
  isopleths (very small) and the mitigation measures (i.e., shutdown zones).
\5\ Authorized take (Level B harassment only) increased to maximum group size from Jefferson et al. (2015).
\6\ Authorized take (Level B harassment only) increased to mean group size from Di Tullio et al. (2016).
\7\ Authorized take (Level B harassment only) increased to 20 individuals, as no densities available.

    It should be noted that the planned take numbers shown in Table 9 
are expected to be conservative for several reasons. First, in the 
calculations of estimated take, 25 percent has been added in the form 
of operational survey days to account for the possibility of additional 
seismic operations associated with airgun testing and repeat coverage 
of any areas where initial data quality is sub-standard, and in 
recognition of the uncertainties in the density estimates used to 
estimate take as described above. Additionally, marine mammals would be 
expected to move away from a loud sound source that represents an 
aversive stimulus, such as an airgun array, potentially reducing the 
likelihood of takes by Level A harassment. However, the extent to which 
marine mammals would move away from the sound source is difficult to 
quantify and is, therefore, not accounted for in the take estimates.

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 such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such 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 such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse

[[Page 60070]]

impact being mitigated (likelihood, scope, range). It further considers 
the likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    SIO has reviewed mitigation measures employed during seismic 
research surveys authorized by NMFS under previous incidental 
harassment authorizations, as well as recommended best practices in 
Richardson et al. (1995), Pierson et al. (1998), Weir and Dolman 
(2007), Nowacek et al. (2013), Wright (2014), and Wright and Cosentino 
(2015), and has incorporated a suite of required mitigation measures 
into their project description based on the above sources.
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, SIO is required to implement mitigation 
measures for marine mammals. Mitigation measures that must be adopted 
during the planned surveys include (1) Vessel-based visual mitigation 
monitoring; (2) Establishment of a marine mammal exclusion zone (EZ) 
and buffer zone; (3) shutdown procedures; (4) ramp-up procedures; and 
(4) vessel strike avoidance measures.

Vessel-Based Visual Mitigation Monitoring

    Visual monitoring requires the use of trained observers (herein 
referred to as visual PSOs) to scan the ocean surface visually for the 
presence of marine mammals. PSO(s) must be on duty and conducting 
visual observations at all times during daylight hours (i.e., from 30 
minutes prior to sunrise through 30 minutes following sunset). Visual 
monitoring must begin not less than 30 minutes prior to ramp-up, 
including for nighttime ramp-ups of the airgun array, and must continue 
until one hour after use of the acoustic source ceases or until 30 
minutes past sunset. Following a shutdown for any reason, observations 
must occur for at least 30 minutes prior to the planned start of airgun 
operations. Observations must also occur for 60 minutes after airgun 
operations cease for any reason (except after sunset). Observations 
must also be made during daytime periods when the Thompson is underway 
without seismic operations, such as during transits, to allow for 
comparison of sighting rates and behavior with and without airgun 
operations and between acquisition periods. Airgun operations must be 
suspended when marine mammals are observed within, or about to enter, 
the designated EZ (as described below).
    During seismic operations, three visual PSOs must be based aboard 
the Thompson. PSOs must be appointed by SIO with NMFS approval. One 
dedicated PSO must monitor the EZ during all daytime seismic 
operations. PSO(s) must be on duty in shifts of duration no longer than 
4 hours. Other vessel crew must also be instructed to assist in 
detecting marine mammals and in implementing mitigation requirements 
(if practical). Before the start of the seismic survey, the crew must 
be given additional instruction in detecting marine mammals and 
implementing mitigation requirements.
    The Thompson is a suitable platform from which PSOs would watch for 
marine mammals. Standard equipment for marine mammal observers must be 
7 x 50 reticule binoculars and optical range finders. At night, night-
vision equipment must be available. The observers must be in 
communication with ship's officers on the bridge and scientists in the 
vessel's operations laboratory, so they can advise promptly of the need 
for avoidance maneuvers or seismic source shutdown.
    The PSOs must have no tasks other than to conduct observational 
effort, record observational data, and communicate with and instruct 
relevant vessel crew with regard to the presence of marine mammals and 
mitigation requirements. PSO resumes shall be provided to NMFS for 
approval. At least one PSO must have a minimum of 90 days at-sea 
experience working as PSOs during a seismic survey. One ``experienced'' 
visual PSO will be designated as the lead for the entire protected 
species observation team. The lead will serve as primary point of 
contact for the vessel operator.

Exclusion Zone and Buffer Zone

    An EZ is a defined area within which occurrence of a marine mammal 
triggers mitigation action intended to reduce the potential for certain 
outcomes, e.g., auditory injury, disruption of critical behaviors. The 
PSOs must establish a minimum EZ with a 100 m radius for the airgun 
array. The 100-m EZ must be based on radial distance from any element 
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, enters, or appears on a 
course to enter this zone, the acoustic source must be shut down (see 
Shutdown Procedures below).
    The 100-m radial distance of the standard EZ is precautionary in 
the sense that it would be expected to contain sound exceeding injury 
criteria for all marine mammal hearing groups (Table 5) while also 
providing a consistent, reasonably observable zone within which PSOs 
would typically be able to conduct effective observational effort. In 
this case, the 100-m radial distance would also be expected to contain 
sound that would exceed the Level A harassment threshold based on sound 
exposure level (SELcum) criteria for all marine mammal 
hearing groups (Table 5). In the 2011 Programmatic Environmental Impact 
Statement for marine scientific research funded by the National Science 
Foundation or the U.S. Geological Survey (NSF-USGS 2011), Alternative B 
(the Preferred Alternative) conservatively applied a 100-m EZ for all 
low-energy acoustic sources in water depths >100 m, with low-energy 
acoustic sources defined as any towed acoustic source with a single or 
a pair of clustered airguns with individual volumes of <=250 in\3\. 
Thus the 100-m EZ planned for this survey is consistent with the PEIS.
    Our intent in prescribing a standard EZ distance is to (1) 
encompass zones within which auditory injury could occur on the basis 
of instantaneous exposure; (2) provide additional protection from the 
potential for more severe behavioral reactions (e.g., panic, 
antipredator response) for marine mammals at relatively close range to 
the acoustic source; (3) provide consistency for PSOs, who need to 
monitor and implement the EZ; and (4) define a distance within which 
detection probabilities are reasonably high for most species under 
typical conditions.
    PSOs will also establish and monitor a 200-m buffer zone. During 
use of the acoustic source, occurrence of marine mammals within the 
buffer zone (but outside the EZ) will be communicated to the operator 
to prepare for potential shutdown of the acoustic source. The buffer 
zone is discussed further under Ramp Up Procedures below.
    An extended EZ of 500 m must be enforced for all beaked whales, 
Kogia species, and Southern right whales. SIO must also enforce a 500-m 
EZ for aggregations of six or more large whales (i.e., sperm whale or 
any baleen whale) that does not appear to be traveling (e.g., feeding, 
socializing, etc.) or a large

[[Page 60071]]

whale with a calf (calf defined as an animal less than two-thirds the 
body size of an adult observed to be in close association with an 
adult).

Shutdown Procedures

    If a marine mammal is detected outside the EZ but is likely to 
enter the EZ, the airguns must be shut down before the animal is within 
the EZ. Likewise, if a marine mammal is already within the EZ when 
first detected, the airguns must be shut down immediately.
    Following a shutdown, airgun activity must not resume until the 
marine mammal has cleared the 100-m EZ. The animal must be considered 
to have cleared the 100-m EZ if the following conditions have been met:
     It is visually observed to have departed the 100-m EZ;
     it has not been seen within the 100-m EZ for 15 min in the 
case of small odontocetes and pinnipeds; or
     it has not been seen within the 100-m EZ for 30 min in the 
case of mysticetes and large odontocetes (including sperm whales), and 
also pygmy sperm whales, dwarf sperm whales, pilot whales, beaked 
whales, and Risso's dolphins.
    This shutdown requirement must be in place for all marine mammals, 
with the exception of small delphinoids under certain circumstances. As 
defined here, the small delphinoid group is intended to encompass those 
members of the Family Delphinidae most likely to voluntarily approach 
the source vessel for purposes of interacting with the vessel and/or 
airgun array (e.g., bow riding). This exception to the shutdown 
requirement would apply solely to specific genera of small dolphins--
Delphinus, Lagenodelphis, Lagenorhynchus, Lissodelphis, Stenella, 
Steno, and Tursiops--and would only apply if the animals were 
traveling, including approaching the vessel. If, for example, an animal 
or group of animals is stationary for some reason (e.g., feeding) and 
the source vessel approaches the animals, the shutdown requirement 
applies. An animal with sufficient incentive to remain in an area 
rather than avoid an otherwise aversive stimulus could either incur 
auditory injury or disruption of important behavior. If there is 
uncertainty regarding identification (i.e., whether the observed 
animal(s) belongs to the group described above) or whether the animals 
are traveling, the shutdown must be implemented.
    We include this small delphinoid exception because shutdown 
requirements for small delphinoids under all circumstances represent 
practicability concerns without likely commensurate benefits for the 
animals in question. Small delphinoids are generally the most commonly 
observed marine mammals in the specific geographic region and would 
typically be the only marine mammals likely to intentionally approach 
the vessel. As described above, auditory injury is extremely unlikely 
to occur for mid-frequency cetaceans (e.g., delphinids), as this group 
is relatively insensitive to sound produced at the predominant 
frequencies in an airgun pulse while also having a relatively high 
threshold for the onset of auditory injury (i.e., permanent threshold 
shift).
    A large body of anecdotal evidence indicates that small delphinoids 
commonly approach vessels and/or towed arrays during active sound 
production for purposes of bow riding, with no apparent effect observed 
in those delphinoids (e.g., Barkaszi et al., 2012). The potential for 
increased shutdowns resulting from such a measure would require the 
Thompson to revisit the missed track line to reacquire data, resulting 
in an overall increase in the total sound energy input to the marine 
environment and an increase in the total duration over which the survey 
is active in a given area. Although other mid-frequency hearing 
specialists (e.g., large delphinoids) are no more likely to incur 
auditory injury than are small delphinoids, they are much less likely 
to approach vessels. Therefore, retaining a power-down/shutdown 
requirement for large delphinoids would not have similar impacts in 
terms of either practicability for the applicant or corollary increase 
in sound energy output and time on the water. We do anticipate some 
benefit for a shutdown requirement for large delphinoids in that it 
simplifies somewhat the total range of decision-making for PSOs and may 
preclude any potential for physiological effects other than to the 
auditory system as well as some more severe behavioral reactions for 
any such animals in close proximity to the source vessel.
    Shutdown of the acoustic source is also required upon observation 
of a species for which authorization has not been granted, or a species 
for which authorization has been granted but the authorized number of 
takes are met, observed approaching or within the Level A or Level B 
harassment zones.

Ramp-up Procedures

    Ramp-up of an acoustic source is intended to provide a gradual 
increase in sound levels following a shutdown, enabling animals to move 
away from the source if the signal is sufficiently aversive prior to 
its reaching full intensity. Ramp-up is required after the array is 
shut down for any reason for longer than 15 minutes. Ramp-up would 
begin with the activation of one 45 in\3\ airgun, with the second 45 
in\3\ airgun activated after 5 minutes.
    Two PSOs are required to monitor during ramp-up. During ramp up, 
the PSOs must monitor the EZ, and if marine mammals were observed 
within the EZ or buffer zone, a shutdown must be implemented as though 
the full array were operational. If airguns have been shut down due to 
PSO detection of a marine mammal within or approaching the 100 m EZ, 
ramp-up must not be initiated until all marine mammals have cleared the 
EZ, during the day or night. Criteria for clearing the EZ would be as 
described above.
    Thirty minutes of pre-clearance observation are required prior to 
ramp-up for any shutdown of longer than 30 minutes (i.e., if the array 
were shut down during transit from one line to another). This 30-minute 
pre-clearance period may occur during any vessel activity (i.e., 
transit). If a marine mammal were observed within or approaching the 
100 m EZ during this pre-clearance period, ramp-up must not be 
initiated until all marine mammals cleared the EZ. Criteria for 
clearing the EZ would be as described above. If the airgun array has 
been shut down for reasons other than mitigation (e.g., mechanical 
difficulty) for a period of less than 30 minutes, it may be activated 
again without ramp-up if PSOs have maintained constant visual 
observation and no detections of any marine mammal have occurred within 
the EZ or buffer zone. Ramp-up must be planned to occur during periods 
of good visibility when possible. However, ramp-up is allowed at night 
and during poor visibility if the 100 m EZ and 200 m buffer zone have 
been monitored by visual PSOs for 30 minutes prior to ramp-up.
    The operator is required to 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. A 
designated PSO must be notified again immediately prior to initiating 
ramp-up procedures and the operator must receive confirmation from the 
PSO to proceed. The operator must provide information to PSOs 
documenting that appropriate procedures were followed. Following 
deactivation of the array for reasons other than mitigation, the 
operator is required to communicate the near-term operational plan to 
the lead PSO with

[[Page 60072]]

justification for any planned nighttime ramp-up.

Vessel Strike Avoidance Measures

    Vessel strike avoidance measures are intended to minimize the 
potential for collisions with marine mammals. 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.
    The required measures include the following: Vessel operator and 
crew must maintain a vigilant watch for all marine mammals and slow 
down or stop the vessel or alter course to avoid striking any marine 
mammal. A visual observer aboard the vessel must monitor a vessel 
strike avoidance zone around the vessel according to the parameters 
stated below. Visual observers monitoring the vessel strike avoidance 
zone may 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. Vessel 
strike avoidance measures must be followed during surveys and while in 
transit.
    The vessel must maintain a minimum separation distance of 100 m 
from large whales (i.e., baleen whales and sperm whales). If a large 
whale is within 100 m of the vessel, the vessel must reduce speed and 
shift the engine to neutral, and must not engage the engines until the 
whale has moved outside of the vessel's path and the minimum separation 
distance has been established. If the vessel is stationary, the vessel 
must not engage engines until the whale(s) has moved out of the 
vessel's path and beyond 100 m. The vessel must maintain a minimum 
separation distance of 50 m from all other marine mammals (with the 
exception of delphinids of the genera Delphinus, Lagenodelphis, 
Lagenorhynchus, Lissodelphis, Stenella, Steno, and Tursiops that 
approach the vessel, as described above). If an animal is encountered 
during transit, the vessel must attempt to remain parallel to the 
animal's course, avoiding excessive speed or abrupt changes in course. 
Vessel speeds must be reduced to 10 kn or less when mother/calf pairs, 
pods, or large assemblages of cetaceans are observed near the vessel.
    Based on our evaluation of the applicant's required measures, NMFS 
has determined that the planned mitigation measures provide the means 
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 in the 
planned action area. Effective reporting is critical both to compliance 
as well as ensuring that the most value is obtained from the required 
monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    SIO described marine mammal monitoring and reporting plan within 
their IHA application. Monitoring that is designed specifically to 
facilitate mitigation measures, such as monitoring of the EZ to inform 
potential shutdowns of the airgun array, are described above and are 
not repeated here. SIO's monitoring and reporting plan includes the 
following measures:

Vessel-Based Visual Monitoring

    As described above, PSO observations must take place during daytime 
airgun operations and nighttime start-ups (if applicable) of the 
airguns. During seismic operations, three visual PSOs must be based 
aboard the Thompson. PSOs must be appointed by SIO with NMFS approval. 
The PSOs must have successfully completed relevant training, including 
completion of all required coursework and passing a written and/or oral 
examination developed for the training program, and must have 
successfully attained a bachelor's degree from an accredited college or 
university with a major in one of the natural sciences and a minimum of 
30 semester hours or equivalent in the biological sciences and at least 
one undergraduate course in math or statistics. The educational 
requirements may be waived if the PSO has acquired the relevant skills 
through alternate training, including (1) secondary education and/or 
experience comparable to PSO duties; (2) previous work experience 
conducting academic, commercial, or government-sponsored marine mammal 
surveys; or (3) previous work experience as a PSO; the PSO should 
demonstrate good standing and consistently good performance of PSO 
duties.
    During the majority of seismic operations, one PSO is required to 
monitor for marine mammals around the seismic vessel. PSOs must be on 
duty in shifts of duration no longer than 4 hours. Other crew must also 
be instructed to assist in detecting marine mammals and in implementing 
mitigation requirements (if practical). During daytime, PSOs must scan 
the area around the vessel systematically with reticle binoculars 
(e.g., 7 x 50 Fujinon) and with the naked eye. At night, PSOs must be 
equipped with night-vision equipment.
    PSOs must record data to estimate the numbers of marine mammals 
exposed to various received sound levels and to document apparent 
disturbance reactions or lack thereof. Data must be used to estimate 
numbers of animals potentially `taken' by harassment (as defined in the 
MMPA). They must also provide information needed to order a shutdown of 
the airguns when a marine mammal is within or near the EZ. When a 
sighting is made, the following information about the sighting must be 
recorded:

[[Page 60073]]

    (1) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc.), and behavioral pace; and
    (2) Time, location, heading, speed, activity of the vessel, sea 
state, visibility, and sun glare.
    All observations and shutdowns must be recorded in a standardized 
format. Data must be entered into an electronic database. The accuracy 
of the data entry must be verified by computerized data validity checks 
as the data are entered and by subsequent manual checking of the 
database. These procedures allow initial summaries of data to be 
prepared during and shortly after the field program and facilitate 
transfer of the data to statistical, graphical, and other programs for 
further processing and archiving. The time, location, heading, speed, 
activity of the vessel, sea state, visibility, and sun glare must also 
be recorded at the start and end of each observation watch, and during 
a watch whenever there is a change in one or more of the variables.
    Results from the vessel-based observations must provide:
    (1) The basis for real-time mitigation (e.g., airgun shutdown);
    (2) Information needed to estimate the number of marine mammals 
potentially taken by harassment, which must be reported to NMFS;
    (3) Data on the occurrence, distribution, and activities of marine 
mammals in the area where the seismic study is conducted;
    (4) Information to compare the distance and distribution of marine 
mammals relative to the source vessel at times with and without seismic 
activity; and
    (5) Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

Reporting

    A draft report must be submitted to NMFS within 90 days after the 
end of the survey. The report must describe the operations that were 
conducted and sightings of marine mammals near the operations. The 
report must provide full documentation of methods, results, and 
interpretation pertaining to all monitoring and must summarize the 
dates and locations of seismic operations, including percentage of time 
and total time the array is active during daylight versus nighttime 
hours (including dawn and dusk), and all marine mammal sightings 
(dates, times, locations, activities, associated seismic survey 
activities). The report must also include estimates of the number and 
nature of exposures that occurred above the harassment threshold based 
on PSO observations, including an estimate of those that were not 
detected in consideration of both the characteristics and behaviors of 
the species of marine mammals that affect detectability, as well as the 
environmental factors that affect detectability.
    The draft report shall also include geo-referenced time-stamped 
vessel tracklines for all time periods during which airguns were 
operating. Tracklines should include points recording any change in 
airgun status (e.g., when the airguns began operating, when they were 
turned off, or when they changed from full array to single gun or vice 
versa). GIS files shall be provided in ESRI shapefile format and 
include the UTC date and time, latitude in decimal degrees, and 
longitude in decimal degrees. All coordinates shall be referenced to 
the WGS84 geographic coordinate system. In addition to the report, all 
raw observational data shall be made available to NMFS. The draft 
report must be accompanied by a certification from the lead PSO as to 
the accuracy of the report, and the lead PSO may submit directly NMFS a 
statement concerning implementation and effectiveness of the required 
mitigation and monitoring. A final report must be submitted within 30 
days following resolution of any comments on the draft report.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, our analysis applies to all the species listed 
in Table 1, given that NMFS expects the anticipated effects of the 
planned seismic survey to be similar in nature. Where there are 
meaningful differences between species or stocks, or groups of species, 
in anticipated individual responses to activities, impact of expected 
take on the population due to differences in population status, or 
impacts on habitat, NMFS has identified species-specific factors to 
inform the analysis.
    NMFS does not anticipate that serious injury or mortality would 
occur as a result of SIO's planned seismic survey, even in the absence 
of planned mitigation. Thus the authorization does not authorize any 
mortality. As discussed in the Potential Effects section, neither 
stranding nor vessel strike are expected to occur.
    No takes by Level A harassment are authorized. The 100-m exclusion 
zone 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 
Thompson's approach due to the vessel's relatively low speed when 
conducting seismic surveys. 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 short-term 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 the Specified 
Activity on Marine Mammals and their Habitat). Marine mammal habitat 
may be impacted by

[[Page 60074]]

elevated sound levels, but these impacts would be temporary. Prey 
species are mobile and are broadly distributed throughout the project 
area; therefore, marine mammals that may be temporarily displaced 
during survey activities are expected to be able to resume foraging 
once they have moved away from areas with disturbing levels of 
underwater noise.
    Because of the 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 planned project area.
    As described above, marine mammals in the survey area are not 
assigned to NMFS stocks. The activity is expected to impact a very 
small percentage of all marine mammal populations, most cases 0.1 
percent or less that would be affected by SIO's planned survey (less 
than 5.3 percent each for all marine mammal populations where abundance 
estimates exist). Additionally, the acoustic ``footprint'' of the 
planned survey would be very small relative to the ranges of all marine 
mammals that would potentially be affected. Sound levels would increase 
in the marine environment in a relatively small area surrounding the 
vessel compared to the range of the marine mammals within the planned 
survey area. The seismic array would be active 24 hours per day 
throughout the duration of the planned survey. However, the very brief 
overall duration of the planned survey (14 days) would further limit 
potential impacts that may occur as a result of the planned activity.
    The required 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 and acoustic observers, and by 
minimizing the severity of any potential exposures via shutdowns of the 
airgun array. The required mitigation (in combination with the small 
Level A harassment zones) will be effective in preventing PTS in all 
species and none is authorized.
    Of the marine mammal species under our jurisdiction that are likely 
to occur in the project area, the following species are listed as 
endangered under the ESA: Fin, sei, blue, sperm, and southern right 
whales. We are proposing to authorize very small numbers of takes for 
these species (Table 9), 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. There is 
no known biological important areas for any of the species listed in 
Table 9. The other marine mammal species that may be taken by 
harassment during SIO'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; of the non-
listed marine mammals for which we propose to authorize take, none are 
considered ``depleted'' or ``strategic'' by NMFS under the MMPA.
    NMFS concludes that exposures to marine mammal species due to SIO's 
planned seismic survey would result in only short-term (temporary and 
short in duration) effects of Level B harassment 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 authorized 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:
     No mortality is anticipated or authorized;
     No take by Level A harassment is anticipated or 
authorized;
     The anticipated impacts of the planned activity on marine 
mammals would primarily be temporary behavioral changes due to 
avoidance of the area around the survey vessel. The relatively short 
duration of the planned survey (14 days) would further limit the 
potential impacts of any temporary behavioral changes that would occur;
     The availability of alternate areas of similar habitat 
value for marine mammals to temporarily vacate the survey area during 
the planned survey to avoid exposure to sounds from the activity;
     The planned project area does not contain areas of 
significance for feeding, mating or calving;
     The potential adverse effects on fish or invertebrate 
species that serve as prey species for marine mammals from the planned 
survey would be temporary and spatially limited; and
     The planned mitigation measures, including visual and 
acoustic monitoring 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 required monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the planned activity will have a negligible impact on all affected 
marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other 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. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    The numbers of marine mammals that we authorize to be taken would 
be considered small relative to the relevant populations (less than 5.3 
percent for all species) for the species for which abundance estimates 
are available. No known current worldwide or regional population 
estimates are available for 16 species under NMFS jurisdiction that 
could be incidentally taken as a result of the planned survey: the 
pygmy right whale, pygmy sperm whale, dwarf sperm whale, Shepherd's 
beaked whale, Blainville's beaked whale, Hector's beaked whale, 
Gervais' beaked whale, True's beaked whale, Andrew's beaked whale, 
spade-toothed beaked whale, rough-toothed dolphin, spinner dolphin, 
Clymene dolphin, Fraser's dolphin, southern right whale dolphin, false 
killer whale, pygmy killer whale, and Melon-headed whale and Cape fur 
seal.
    NMFS has reviewed the geographic distributions and habitat 
preferences of these species in determining whether the numbers of 
takes authorized herein are likely to represent small numbers. Pygmy 
right whales have a circumglobal distribution and occur throughout 
coastal and oceanic waters in the Southern Hemisphere (between 30 to 
55[deg] S) (Jefferson et al. 2015; Kemper

[[Page 60075]]

2018). Pygmy and dwarf sperm whales occur in deep waters on the outer 
continental shelf and slope in tropical to temperate waters of the 
Atlantic, Indian, and Pacific Oceans, but their precise distributions 
are unknown because much of what we know of the species comes from 
strandings (McAlpine, 2018). Based on stranding records and the known 
habitat preferences of beaked whales in general, Shepherd's beaked 
whales are assumed to have a circumpolar distribution in deep, cold 
temperate waters of the Southern Ocean (Pitman et al., 2006; Mead 
2018). Blainville's beaked whale is the most widely distributed beaked 
Mesoplodon species with sightings and stranding records throughout the 
North and South Atlantic Ocean (MacLeod et al., 2006; Pitman, 2018). 
Hector's beaked whales are found in cold temperate waters throughout 
the southern hemisphere between 35[deg] S and 55[deg] S (Zerbini and 
Secchi, 2001; Pitman, 2018). True's beaked whale has a disjunct, 
antitropical distribution (Jefferson et al., 2015). In the Southern 
Hemisphere, it is known to occur in South Africa, South America, and 
Australia (Findlay et al. 1992; Souza et al., 2005; MacLeod and 
Mitchell 2006; MacLeod et al., 2006; Best et al., 2009). Andrew's 
beaked whales have a circumpolar distribution north of the Antarctic 
Convergence to 32[deg] S (MacLeod et al., 2006; Pitman, 2018). Andrew's 
beaked whale is known only from stranding records between 32[deg] S and 
55[deg] S, with more than half of the strandings occurring in New 
Zealand (Jefferson et al., 2015). Gervais' beaked whale is generally 
considered to be a North Atlantic species, it likely occurs in deep 
waters of the temperate and tropical Atlantic Ocean in both the 
northern and southern hemispheres (Jefferson et al., 2015). The 
southernmost stranding record was reported for S[atilde]o Paulo, 
Brazil, possibly expanding the known distributional range of this 
species southward (Santos et al., 2003), but the distribution range of 
Gervais' beaked whale is not generally known to extend as far south as 
the planned project area. The spade-toothed beaked whale is considered 
relatively rare and is known from only four records, three from New 
Zealand and one from Chile (Thompson et al., 2012). The rough-toothed 
dolphin is distributed worldwide in tropical and subtropical waters 
(Jefferson et al., 2015). Rough-toothed dolphins are generally seen in 
deep, oceanic water, although it is known to occur in coastal waters of 
Brazil (Jefferson et al., 2015; Cardoso et al., 2019). The Clymene 
dolphin only occurs in tropical and subtropical waters of the Atlantic 
Ocean (Jefferson et al., 2015). Clymeme dolphins inhabits areas where 
water depths are 700-4,500 m or deeper (Fertl et al., 2003). Fraser's 
dolphins are distributed in tropical oceanic waters worldwide, between 
30[deg] N and 30[deg] S and generally inhabits deeper, offshore water 
(Moreno et al., 2003, Dolar 2018). The southern right whale dolphin is 
distributed between the Subtropical and Antarctic convergences in the 
Southern Hemisphere, generally between ~30[deg] S and 65[deg] S 
(Jefferson et al., 2015; Lipsky and Brownell, 2018). The false killer 
whale is found worldwide in tropical and temperate waters, generally 
between 50 [deg] N and 50[deg] S (Odell and McClune, 1999). It is 
widely distributed, but not abundant anywhere (Carwardine, 1995). The 
false killer whale generally inhabits deep, offshore waters, but 
sometimes is found over the continental shelf and occasionally moves 
into very shallow water (Jefferson et al., 2015; Baird, 2018b). The 
pygmy killer whale has a worldwide distribution in tropical and 
subtropical waters, generally not ranging south of 35[deg] S (Jefferson 
et al. 2015). The melon-headed whale is an oceanic species found 
worldwide in tropical and subtropical waters from ~40[deg] N to 35[deg] 
S (Jefferson et al., 2015). The Cape fur seal currently breeds at 40 
colonies along the coast of South Africa, Namibia, and Angola, 
including on the mainland and nearshore islands (Kirkman et al., 2013). 
There have been several new breeding colonies established in recent 
years, as the population has shifted northward (Kirkman et al., 2013). 
More than half of the seal population occurs in Namibia (Wickens et 
al., 1991). High densities have been observed between 30 and 60 nm from 
shore, with densities dropping farther offshore (Thomas and 
Sch[uuml]lein, 1988).
    Based on the broad spatial distributions and habitat preferences of 
these species relative to the areas where SIO's planned survey will 
occur, NMFS concludes that the authorized take of these species likely 
represent small numbers relative to the affected species' overall 
population sizes, though we are unable to quantify the take numbers as 
a percentage of population.
    Based on the analysis contained herein of the planned activity 
(including the required mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

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

National Environmental Policy Act

    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 incidental 
harassment authorization) with respect to potential impacts on the 
human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (incidental harassment authorizations 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 (ESA)

    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, in this case with the ESA Interagency 
Cooperation Division, whenever we propose to authorize take for 
endangered or threatened species.
    The NMFS Office of Protected Resources Interagency Cooperation 
Division issued a Biological Opinion on October 29, 2019, under section 
7 of the ESA, on the issuance of an IHA to SIO under section 
101(a)(5)(D) of the MMPA by the NMFS Permits and Conservation Division. 
The Biological Opinion concluded that the proposed action is not likely 
to jeopardize the continued existence of fin whale, sei whale, blue

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whale, sperm whale, and southern right whale, and is not likely to 
destroy or modify critical habitat of listed species because no 
critical habitat exists for these species in the action area.

Authorization

    As a result of these determinations, NMFS has issued an IHA to SIO 
for conducting a marine geophysical survey in the South Atlantic Ocean 
in November and December 2019, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated.

    Dated: November 1, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-24265 Filed 11-6-19; 8:45 am]
 BILLING CODE 3510-22-P