Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Low-Energy Geophysical Survey in the South Atlantic Ocean, 60059-60076 [2019-24265]
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DEPARTMENT OF COMMERCE
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Takes of Marine Mammals Incidental to
Specified Activities; Taking Marine
Mammals Incidental to a Low-Energy
Geophysical Survey in the South
Atlantic Ocean
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice; Issuance of an Incidental
Harassment Authorization.
AGENCY:
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.
SUMMARY:
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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-undermarine-mammal-protection-act. In case
of problems accessing these documents,
please call the contact listed above.
SUPPLEMENTARY INFORMATION:
DATES:
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
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60059
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 NovemberDecember 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.
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Federal Register / Vol. 84, No. 216 / Thursday, November 7, 2019 / Notices
The highest-quality mode is carried
out using a pair of 45-in3 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 45in 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
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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
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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 NSFfunded 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 reestimate 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
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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 NSFaffiliated entities and all seismic
operators should use this method as
well.
Response: We thank the Commission
for their recommendation. NMFS is in
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17:55 Nov 06, 2019
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the process of determining the
appropriate method for deriving postsurvey 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 NSFfunded 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
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60061
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
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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/marinemammal-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
Common name
ESA/
MMPA
status;
strategic
(Y/N) 2
Stock 1
Scientific name
Abundance
PBR
Relative
occurrence in
project area
Order Cetartiodactyla—Cetacea—Superfamily Mysticeti (baleen whales)
Family Balaenidae
Southern right whale .........................
Eubalaena australis ..........................
n/a ...............
E/D; N
12,000 3 .................................
3,3005 ...................................
N.A. .........
Uncommon.
N.A. .......................................
N.A. .........
Rare.
2,300 true 4 ...........................
1,500 pygmy 6 .......................
15,000 6 .................................
10,000 6 .................................
515,000 3 6 .............................
515,000 3 6 .............................
42,000 3 .................................
48,109 7 .................................
N.A. .........
Rare.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
.........
.........
.........
.........
.........
.........
Uncommon.
Uncommon.
Common.
Common.
Rare.
Common.
12,069 10 ...............................
N.A. .........
Uncommon.
N.A. .......................................
N.A. .......................................
N.A. .........
N.A. .........
Rare.
Uncommon.
599,300 11 .............................
599,300 11 .............................
599,300 11 .............................
N.A. .......................................
N.A. .......................................
599,300 11 .............................
N.A. .......................................
N.A. .......................................
N.A. .......................................
599,300 11 .............................
N.A. .......................................
N.A. .......................................
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
Uncommon.
Uncommon.
Uncommon.
Uncommon.
Rare.
Uncommon.
Rare.
Rare.
Rare.
Uncommon.
Rare.
Rare.
18,250 12 ...............................
N.A. .......................................
77,532 12 ...............................
3,333 12 .................................
44,715 12 ...............................
N.A. .......................................
N.A. .......................................
54,807 12 ...............................
70,184 10 ...............................
N.A. .......................................
7,252 12 .................................
150,000 6 ...............................
N.A. .......................................
25,000 14 ...............................
200,000 6 ...............................
200,000 6 ...............................
N.A. .......................................
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
Common.
Common.
Uncommon.
Common.
Rare.
Uncommon.
Rare.
Uncommon.
Uncommon.
Uncommon.
Rare.
Rare.
Uncommon.
Uncommon.
Uncommon.
Uncommon.
Uncommon.
Family Cetotheriidae
Pygmy right whale .............................
Caperea marginata ...........................
n/a ...............
Blue whale .........................................
Balaenoptera musculus ....................
n/a ...............
E/D; Y
Fin whale ...........................................
Sei whale ...........................................
Common minke whale .......................
Antarctic minke whale .......................
Humpback whale ...............................
Bryde’s whale ....................................
Balaenoptera physalus .....................
Balaenoptera borealis ......................
Balaenoptera acutorostrata ..............
Balaenoptera bonaerensis ...............
Megaptera novaeangliae ..................
Balaenoptera edeni/brydei ...............
n/a
n/a
n/a
n/a
n/a
n/a
E/D; Y
E
Family Balaenopteridae (rorquals)
...............
...............
...............
...............
...............
...............
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
Family Physeteridae
Sperm whale .....................................
Physeter macrocephalus ..................
n/a ...............
E
Family Kogiidae
Pygmy sperm whale ..........................
Dwarf sperm whale ...........................
Kogia breviceps ................................
Kogia sima ........................................
n/a ...............
n/a ...............
Family Ziphiidae (beaked whales)
Arnoux’s beaked whale .....................
Cuvier’s beaked whale ......................
Southern bottlenose whale ................
Shepherd’s beaked whale .................
Blainville’s beaked whale ..................
Gray’s beaked whale .........................
Gervais’ beaked whale ......................
Hector’s beaked whale ......................
True’s beaked whale .........................
Strap-toothed beaked whale .............
Andrews’ beaked whale ....................
Spade-toothed beaked whale ...........
Berardius arnuxii ..............................
Ziphius cavirostris .............................
Hyperoodon planifrons .....................
Tasmacetus sheperdi .......................
Mesoplodon densirostris ..................
Mesoplodon grayi .............................
Mesoplodon europaeus ....................
Mesoplodon hectori ..........................
Mesoplodon mirus ............................
Mesoplodon layardii .........................
Mesoplodon bowdoini .......................
Mesoplodon traversii ........................
n/a
n/a
n/a
n/a
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Family Delphinidae
Risso’s dolphin ..................................
Rough-toothed dolphin ......................
Common bottlenose dolphin .............
Pantropical spotted dolphin ...............
Atlantic spotted dolphin .....................
Spinner dolphin .................................
Clymene dolphin ................................
Striped dolphin ..................................
Short-beaked common dolphin .........
Fraser’s dolphin .................................
Dusky dolphin ....................................
Hourglass dolphin ..............................
Southern right whale dolphin ............
Killer whale ........................................
Short-finned pilot whale .....................
Long-finned pilot whale .....................
False killer whale ...............................
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Grampus griseus ..............................
Steno bredanensis ...........................
Tursiops truncatus ............................
Stenella attenuata ............................
Stenella frontalis ...............................
Stenella longirostris ..........................
Stenella clymene ..............................
Stenella coeruleoalba .......................
Delphinus delphis .............................
Lagenodelphis hosei ........................
Lagenorhynchus obscurus ...............
Lagenorhynchus cruciger .................
Lissodelphis peronii ..........................
Orcinus orca .....................................
Globicephala macrorhynchus ...........
Globicephala melas ..........................
Pseudorca crassidens ......................
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Federal Register / Vol. 84, No. 216 / Thursday, November 7, 2019 / Notices
TABLE 1—MARINE MAMMAL SPECIES POTENTIALLY PRESENT IN THE PROJECT AREA EXPECTED TO BE AFFECTED BY THE
SPECIFIED ACTIVITIES—Continued
Common name
Scientific name
Stock 1
Pygmy killer whale ............................
Melon-headed whale .........................
Feresa attenuata ..............................
Peponocephala electra .....................
n/a ...............
n/a ...............
ESA/
MMPA
status;
strategic
(Y/N) 2
Relative
occurrence in
project area
Abundance
PBR
N.A. .......................................
N.A. .......................................
N.A. .........
N.A. .........
Uncommon.
Uncommon.
Approximately 2 million 16 .....
400,000 15 .............................
N.A. .........
N.A. .........
Uncommon.
Uncommon.
5—10 million 17 .....................
222,000—440,000 18 .............
750,000 19 .............................
N.A. .........
N.A. .........
N.A. .........
Rare.
Rare.
Uncommon.
Order Carnivora—Superfamily Pinnipedia
Family Otariidae (eared seals and sea lions)
Cape fur seal .....................................
Subantarctic fur seal .........................
Arctocephalus pusillus pusillus ........
Arctocephalus tropicalis ...................
n/a ...............
n/a ...............
Family Phocidae (earless seals)
Crabeater seal ...................................
Leopard seal ......................................
Southern elephant seal .....................
Lobodon carcinophaga .....................
Hydrurga leptonyx ............................
Mirounga leonina ..............................
n/a ...............
n/a ...............
n/a ...............
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°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.
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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
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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
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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 mPa (rms)
for continuous (e.g., vibratory piledriving, drilling) and above 160 dB re 1
mPa (rms) for non-explosive impulsive
(e.g., seismic airguns) or intermittent
(e.g., scientific sonar) sources.
SIO’s planned activity includes the
use of impulsive seismic sources, and
therefore the 160 dB re 1 mPa (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 nonimpulsive). 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-technicalguidance.
TABLE 2—THRESHOLDS IDENTIFYING THE ONSET OF PERMANENT THRESHOLD SHIFT
PTS Onset acoustic thresholds *
(received level)
Hearing group
Impulsive
Low-Frequency (LF) Cetaceans ......................................
Mid-Frequency (MF) Cetaceans ......................................
High-Frequency (HF) Cetaceans .....................................
Phocid Pinnipeds (PW) (Underwater) .............................
Otariid Pinnipeds (OW) (Underwater) .............................
Cell
Cell
Cell
Cell
Cell
1:
3:
5:
7:
9:
Lpk,flat:
Lpk,flat:
Lpk,flat:
Lpk,flat:
Lpk,flat:
219
230
202
218
232
Non-impulsive
dB; LE, LF,24h: 183 dB .......................
dB LE, MF,24h: 185 dB .......................
dB LE, HF,24h: 155 dB ........................
dB LE, PW,24h: 185 dB .......................
dB LE,OW,24h: 203 dB ........................
Cell
Cell
Cell
Cell
Cell
2: LE, LF,24h: 199 dB
4: LE, MF,24h: 198 dB
6: LE, HF,24h: 173 dB
8: LE,PW,24h: 201 dB
10: LE,OW,24h: 219 dB
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds associated with impulsive sounds, these thresholds should
also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 μPa, and cumulative sound exposure level (LE) has a reference value of 1μPa2s.
In this Table, thresholds are abbreviated to reflect American National Standards Institute standards (ANSI 2013). However, peak sound pressure
is defined by ANSI as incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ‘‘flat’’ is being
included to indicate peak sound pressure should be flat weighted or unweighted within the generalized hearing range. The subscript associated
with cumulative sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF, and HF
cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The cumulative sound exposure level
thresholds could be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for
action proponents to indicate the conditions under which these acoustic thresholds will be exceeded.
Ensonified Area
Here, we describe operational and
environmental parameters of the activity
that will feed into identifying the area
ensonified above the acoustic
thresholds, which include source levels
and transmission loss coefficient.
The planned survey would entail the
use of a 2-airgun array with a total
discharge of 90 in3 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)
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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 in3 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-
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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
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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-seafloorrefracted 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-in3 guns at a tow depth
of 2–4 m. For deep water (>1,000 m), we
60065
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 160 dB
received
sound level
Airgun configuration
Water depth (m)
Two 45 in3 guns, 2-m separation .............................................
>1,000 (deep) ...........................................................................
100–1,000 (intermediate) .........................................................
> 1,000 (deep) ..........................................................................
100–1,000 (intermediate) .........................................................
Two 45 in3 guns, 8-m separation .............................................
a 539
b 809
a 578
b 867
a Distance
based on LDEO model results.
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.
b Distance
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
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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
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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
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Federal Register / Vol. 84, No. 216 / Thursday, November 7, 2019 / Notices
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 IN3 AIRGUN ARRAYS
8-kn survey
with 8-m
airgun
separation:
Peak SPLflat
Functional hearing group
Low frequency cetaceans (Lpk,flat: 219 dB; LE,LF,24h: 183 dB) .......................
Mid frequency cetaceans (Lpk,flat: 230 dB; LE,MF,24h: 185 dB) .......................
High frequency cetaceans (Lpk,flat: 202 dB; LE,HF,24h: 155 dB) ......................
Phocid Pinnipeds (Underwater) (Lpk,flat: 218 dB; LE,HF,24h: 185 dB) ..............
Otariid Pinnipeds (Underwater) (Lpk,flat: 232 dB; LE,HF,24h: 203 dB) ..............
8-kn survey
with 8-m
airgun
separation:
SELcum
228.8
1 N/A
233
230
1 N/A
207
206.7
207.6
206.7
203
5-kn survey
with 2-m
airgun
separation:
Peak SPLflat
232.8
229.8
232.9
232.8
225.6
5-kn survey
with 2-m
airgun
separation:
SELcum
206.7
206.9
207.2
206.9
207.4
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 (mPa) in order to
integrate them over the entire
broadband spectrum, resulting in
broadband weighted source levels by
hearing group that could be directly
incorporated within the User
Spreadsheet (i.e., to override the
Spreadsheet’s more simple weighting
factor adjustment). Using the User
Spreadsheet’s ‘‘safe distance’’
methodology for mobile sources
(described by Sivle et al., 2014) with the
hearing group-specific weighted source
levels, and inputs assuming spherical
spreading propagation and source
velocities and shot intervals 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
with 8-m
airgun
separation:
Peak SPLflat
Functional Hearing Group (Level A harassment thresholds)
Low frequency cetaceans (Lpk,flat: 219 dB; LE,LF,24h: 183 dB) .......................
Mid frequency cetaceans (Lpk,flat: 230 dB; LE,MF,24h: 185 dB) .......................
High frequency cetaceans (Lpk,flat: 202 dB; LE,HF,24h: 155 dB) ......................
Phocid Pinnipeds (Underwater) (Lpk,flat: 218 dB; LE,HF,24h: 185 dB) ..............
Otariid Pinnipeds (Underwater) (Lpk,flat: 232 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
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3.08
0
34.84
4.02
0
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
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8-kn survey
with 8-m
airgun
separation:
SELcum
2.4
0
0
0
0
5-kn survey
with 2-m
airgun
separation:
Peak SPLflat
4.89
0.98
34.62
5.51
0.48
5-kn survey
with 2-m
airgun
separation:
SELcum
6.5
0
0
0.1
0
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
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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
density
(#/km2) a
Species
LF Cetaceans
Southern right whale ............
Pygmy right whale ................
Blue whale ............................
Fin whale ..............................
Sei whale ..............................
0.007965
N.A.
0.000051
0.000356
0.000086
TABLE 6—MARINE MAMMAL DENSITIES
IN THE PLANNED SURVEY AREA—
Continued
TABLE 6—MARINE MAMMAL DENSITIES
IN THE PLANNED SURVEY AREA—
Continued
Estimated
density
(#/km2) a
Species
Bryde’s whale .......................
Common (dwarf) minke
whale .................................
Antarctic minke whale ..........
Humpback whale ..................
0.000439
Cape fur seal ........................
Crabeater seal ......................
Leopard seal .........................
Southern elephant seal ........
MF Cetaceans
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 (km2) expected to be
ensonified to the Level A and Level B
harassment thresholds for each survey
type (Table 7).
0.717166
0.021040
0.012867
0.006827
0.000266
0.002085
0.021379
0.000882
0.000321
0.003540
HF Cetaceans
0.003418
0.002582
0.011122
Otariids
Subantarctic fur seal .............
0.00649
0.00162
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.
0.005975
0.011379
0.000548
0.007906
0.009269
0.000053
0.001885
0.000212
0.001323
0.000053
0.000582
0.000159
0.000053
0.010657
0.005954
0.040308
0.003767
0.213721
0.040720
0.006800
0.004089
Pygmy sperm whale .............
Dwarf sperm whale ...............
Hourglass dolphin .................
N.A.
Phocids
0.077896
0.077896
0.000310
Sperm whale .........................
Arnoux’s beaked whale ........
Cuvier’s beaked whale .........
Southern bottlenose whale ...
Shepherd’s beaked whale ....
Blainville’s beaked whale .....
Gray’s beaked whale ............
Hector’s beaked whale .........
Gervais’ beaked whale .........
True’s beaked whale ............
Strap-toothed beaked whale
Andrew’s beaked whale .......
Spade-toothed beaked whale
Risso’s dolphin .....................
Rough-toothed dolphin .........
Common bottlenose dolphin
Pantropical spotted dolphin ..
Atlantic spotted dolphin ........
Spinner dolphin .....................
Clymene dolphin ...................
Striped dolphin ......................
Short-beaked common dolphin ...................................
Fraser’s dolphin ....................
Dusky dolphin .......................
Southern right whale dolphin
Killer whale ...........................
Short-finned pilot whale ........
Long-finned pilot whale ........
False killer whale ..................
Pygmy killer whale ................
Melon-headed whale ............
Estimated
density
(#/km2) a
Species
0.00274
TABLE 7—AREAS (km2) TO BE ENSONIFIED TO LEVEL A AND LEVEL B HARASSMENT THRESHOLDS
Survey type
Relevant
isopleth
(m)
Criteria
5-kn survey .........................
Daily
ensonified
area (km2)
Total survey
days
25 percent increase
Total
ensonified
area
(km2)
Level B Harassment (160 dB)
Intermediate water .............
Deep water .........................
809
539
14.67
231.31
10
10
1.25
1.25
183.34
2891.42
10
10
10
1.25
1.25
1.25
36.125
5.55
192.13
Level A Harassment
LF cetacean .......................
MF cetacean ......................
HF cetacean .......................
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0.44
15.37
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TABLE 7—AREAS (km2) TO BE ENSONIFIED TO LEVEL A AND LEVEL B HARASSMENT THRESHOLDS—Continued
Survey type
Relevant
isopleth
(m)
Criteria
Phocids ...............................
Otariids ...............................
Daily
ensonified
area (km2)
5.5
0.5
8-kn survey .........................
Total survey
days
2.44
0.22
25 percent increase
Total
ensonified
area
(km2)
10
10
1.25
1.25
30.53
2.77
4
4
1.25
1.25
129.75
1979.38
4
4
4
4
4
1.25
1.25
1.25
1.25
1.25
11.04
0
124
14.24
0
Otariids Level A ....................
2.77
Level B Harassment (160 dB)
Intermediate water .............
Deep water .........................
867
578
25.95
395.88
Level A Harassment
LF cetacean .......................
MF cetacean ......................
HF cetacean .......................
Phocids ...............................
Otariids ...............................
The total ensonified areas (km2) 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
(km2) FOR ALL SURVEYS
Criteria
160 dB Level B (all depths) ..
Total
ensonified
area (km2) for
all surveys
5183.89
3.1
0
34.8
4
0
2.21
0
24.78
2.85
0
TABLE 8—TOTAL ENSONIFIED AREAS
(km2) FOR ALL SURVEYS—Continued
Total
ensonified
area (km2) for
all surveys
Criteria
160 dB Level B (intermediate
water) ................................
160 dB Level B (deep water)
LF cetacean Level A ............
MF cetacean Level A ...........
HF cetacean Level A ............
Phocids Level A ....................
313.09
4870.80
47.11
5.55
316.04
44.77
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
Species
Level B
harassment 2
LF Cetaceans:
Southern right whale ................................................................................
Pygmy right whale ....................................................................................
Blue whale ................................................................................................
Fin whale ..................................................................................................
Sei whale ..................................................................................................
Bryde’s whale ...........................................................................................
Common (dwarf) minke whale ..................................................................
Antarctic minke whale ..............................................................................
Humpback whale ......................................................................................
MF Cetaceans:
Sperm whale .............................................................................................
Arnoux’s beaked whale ............................................................................
Cuvier’s beaked whale .............................................................................
Southern bottlenose whale .......................................................................
Shepherd’s beaked whale ........................................................................
Blainville’s beaked whale .........................................................................
Gray’s beaked whale ................................................................................
Hector’s beaked whale .............................................................................
Gervais’ beaked whale .............................................................................
True’s beaked whale ................................................................................
Strap-toothed beaked whale ....................................................................
Andrew’s beaked whale ...........................................................................
Spade-toothed beaked whale ...................................................................
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Authorized
take 4
Level A
harassment 3
Level B
harassment
only
41
N.A.
0
2
0
2
400
400
2
0
N.A.
0
0
0
0
4
4
0
36
46
36
20 5
404
404
2035
1.3
N.A.
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
0
31
59
3
41
48
0
10
1
7
0
3
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31
59
3
41
48
76
10
26
7
26
3
26
26
0.3
<0.1
<0.1
<0.1
N.A.
N.A.
<0.1
N.A.
N.A.
N.A.
<0.1
N.A.
N.A.
E:\FR\FM\07NON1.SGM
07NON1
41
Percent of
population 5
52
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TABLE 9—CALCULATED AND AUTHORIZED LEVEL A AND LEVEL B EXPOSURES, AND PERCENTAGE OF POPULATION
EXPOSED—Continued
Calculated take 1
Species
Level B
harassment 2
Risso’s dolphin .........................................................................................
Rough-toothed dolphin .............................................................................
Common bottlenose dolphin .....................................................................
Pantropical spotted dolphin ......................................................................
Atlantic spotted dolphin ............................................................................
Spinner dolphin .........................................................................................
Clymene dolphin .......................................................................................
Striped dolphin ..........................................................................................
Short-beaked common dolphin .................................................................
Fraser’s dolphin ........................................................................................
Dusky dolphin ...........................................................................................
Southern right whale dolphin ....................................................................
Killer whale ...............................................................................................
Short-finned pilot whale ............................................................................
Long-finned pilot whale ............................................................................
False killer whale ......................................................................................
Pygmy killer whale ....................................................................................
Melon-headed whale ................................................................................
HF Cetaceans:
Pygmy sperm whale .................................................................................
Dwarf sperm whale ...................................................................................
Hourglass dolphin .....................................................................................
Otariids:
Subantarctic fur seal .................................................................................
Cape fur seal ............................................................................................
Phocids:
Crabeater seal ..........................................................................................
Leopard seal .............................................................................................
Southern elephant seal ............................................................................
Authorized
take 4
Level A
harassment 3
Level B
harassment
only
Percent of
population 5
55
31
209
20
1108
211
35
21
3714
109
67
35
1
11
111
5
2
18
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
0
78 6
55 6
209
104 6
1108
315 6
122 6
110 5
3718
283 6
67
35
86
41 6
111
35 6
26 6
170 6
0.3
N.A.
0.3
0.6
2.5
N.A.
N.A.
<0.1
5.3
N.A.
0.9
N.A.
<0.1
<0.1
0.1
N.A.
N.A.
N.A.
17
12
54
1
1
4
18
13
58
N.A.
N.A.
<0.1
14
N.A.
0
N.A.
14
20 7
<0.1
N.A.
34
8
8
0
0
0
34
8
8
<0.1
<0.1
<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 μParms 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
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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
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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
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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
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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
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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 in3. 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
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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 100m EZ for 15 min in the case of small
odontocetes and pinnipeds; or
• it has not been seen within the 100m 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
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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 midfrequency cetaceans (e.g., delphinids),
as this group is relatively insensitive to
sound produced at the predominant
frequencies in an airgun pulse while
also having a relatively high threshold
for the onset of auditory injury (i.e.,
permanent threshold shift).
A large body of anecdotal evidence
indicates that small 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
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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 in3
airgun, with the second 45 in3 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 rampup 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
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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
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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
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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 × 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:
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(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
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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., populationlevel effects). An estimate of the number
of takes alone is not enough information
on which to base an impact
determination. In addition to
considering estimates of the number of
marine mammals that might be ‘‘taken’’
through harassment, NMFS considers
other factors, such as the likely nature
of any responses (e.g., intensity,
duration), the context of any responses
(e.g., critical reproductive time or
location, migration), as well as effects
on habitat, and the likely effectiveness
of the mitigation. We also assess the
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60073
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
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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
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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 ESAlisted 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
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• 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° S) (Jefferson et al. 2015; Kemper
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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° S and 55° 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° S (MacLeod et al., 2006; Pitman,
2018). Andrew’s beaked whale is known
only from stranding records between 32°
S and 55° 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 Sa˜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 spadetoothed 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
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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° N and 30° 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° S
and 65° S (Jefferson et al., 2015; Lipsky
and Brownell, 2018). The false killer
whale is found worldwide in tropical
and temperate waters, generally
between 50 ° N and 50° 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° S (Jefferson et al. 2015). The melonheaded whale is an oceanic species
found worldwide in tropical and
subtropical waters from ∼40° N to 35° 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 Schu¨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.
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60075
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
E:\FR\FM\07NON1.SGM
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Federal Register / Vol. 84, No. 216 / Thursday, November 7, 2019 / Notices
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
DEPARTMENT OF DEFENSE
Office of the Secretary
Defense Advisory Committee on
Women in the Services; Notice of
Federal Advisory Committee Meeting
Under Secretary of Defense for
Personnel and Readiness, Department of
Defense (DoD).
ACTION: Notice of Federal Advisory
Committee meeting.
AGENCY:
The DoD is publishing this
notice to announce that the following
Federal Advisory Committee meeting of
the Defense Advisory Committee on
Women in the Services will take place.
DATES: Day 1—Open to the public
Wednesday, December 4, 2019 from
8:00 a.m. to 12:30 p.m. Day 2—Open to
the public Thursday, December 5, 2019
from 8:00 a.m. to 11:30 a.m.
ADDRESSES: The address of the open
meeting is the Key Bridge Marriott,
located at 1401 Lee Highway, Arlington,
VA 22209.
FOR FURTHER INFORMATION CONTACT:
Colonel Toya J. Davis, U.S. Army, (703)
697–2122 (Voice), 703–614–6233
(Facsimile), toya.j.davis.mil@mail.mil
(Email). Mailing address is 4800 Mark
Center Drive, Suite 04J25–01,
Alexandria, VA 22350. Website: https://
dacowits.defense.gov. The most up-todate changes to the meeting agenda can
be found on the website.
SUPPLEMENTARY INFORMATION: This
meeting is being held under the
provisions of the Federal Advisory
Committee Act (FACA) of 1972 (5
U.S.C., Appendix, as amended), the
Government in the Sunshine Act of
SUMMARY:
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17:55 Nov 06, 2019
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1976 (5 U.S.C. 552b, as amended), and
41 CFR 102–3.140 and 102–3.150.
Purpose of the Meeting: The purpose
of the meeting is for the DACOWITS to
receive written information and
briefings on topics related to the
recruitment, retention, employment,
integration, well-being, and treatment of
women in the Armed Forces of the
United States.
Agenda: Wednesday, December 4,
2019, from 8:00 a.m. to 12:30 p.m.—
Welcome, Introductions, and
Announcements; Request for
Information Status Update; Briefings
and DACOWITS discussion; and a
Public Comment Period. Thursday,
December 5, 2019, from 8:00 a.m. to
11:30 a.m.—Welcome, Introductions,
and Announcements; Briefings and
DACOWITS discussion.
Meeting Accessibility: Pursuant to 5
U.S.C. 552b, as amended, and 41 CFR
102–3.140 through 102–3.165, this
meeting is open to the public, subject to
the availability of space.
Written Statements: Pursuant to 41
CFR 102–3.140, and section 10(a)(3) of
the FACA, interested persons may
submit a written statement to the
DACOWITS. Individuals submitting a
written statement must submit their
statement no later than 5:00 p.m.,
Tuesday, November 26, 2019 to Mr.
Robert Bowling (703) 697–2122 (Voice),
703–614–6233 (Facsimile),
osd.pentagon.ousd-p-r.mbx.dacowits@
mail.mil (Email). Mailing address is
4800 Mark Center Drive, Suite 04J25–01,
Alexandria, VA 22350. If members of
the public are interested in making an
oral statement, a written statement must
be submitted. If a statement is not
received by Tuesday, November 26,
2019, prior to the meeting, which is the
subject of this notice, then it may not be
provided to or considered by the
Committee during this quarterly
business meeting. After reviewing the
written statements, the Chair and the
Designated Federal Officer (DFO) will
determine if the requesting persons are
permitted to make an oral presentation.
The DFO will review all timely
submissions with the DACOWITS Chair
and ensure they are provided to the
members of the Committee.
Dated: November 1, 2019.
Aaron T. Siegel,
Alternate OSD Federal Register Liaison
Officer, Department of Defense.
[FR Doc. 2019–24264 Filed 11–6–19; 8:45 am]
BILLING CODE 5001–06–P
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DEPARTMENT OF ENERGY
Federal Energy Regulatory
Commission
[Docket No. ER20–242–000]
Supplemental Notice That Initial
Market-Based Rate Filing Includes
Request for Blanket Section 204
Authorization: Sunshine Valley Solar,
LLC
This is a supplemental notice in the
above-referenced proceeding of
Sunshine Valley Solar, LLC’s
application for market-based rate
authority, with an accompanying rate
tariff, noting that such application
includes a request for blanket
authorization, under 18 CFR part 34, of
future issuances of securities and
assumptions of liability.
Any person desiring to intervene or to
protest should file with the Federal
Energy Regulatory Commission, 888
First Street NE, Washington, DC 20426,
in accordance with Rules 211 and 214
of the Commission’s Rules of Practice
and Procedure (18 CFR 385.211 and
385.214). Anyone filing a motion to
intervene or protest must serve a copy
of that document on the Applicant.
Notice is hereby given that the
deadline for filing protests with regard
to the applicant’s request for blanket
authorization, under 18 CFR part 34, of
future issuances of securities and
assumptions of liability, is November
21, 2019.
The Commission encourages
electronic submission of protests and
interventions in lieu of paper, using the
FERC Online links at https://
www.ferc.gov. To facilitate electronic
service, persons with internet access
who will eFile a document and/or be
listed as a contact for an intervenor
must create and validate an
eRegistration account using the
eRegistration link. Select the eFiling
link to log on and submit the
intervention or protests.
Persons unable to file electronically
should submit an original and 5 copies
of the intervention or protest to the
Federal Energy Regulatory Commission,
888 First Street NE, Washington, DC
20426.
The filings in the above-referenced
proceeding are accessible in the
Commission’s eLibrary system by
clicking on the appropriate link in the
above list. They are also available for
electronic review in the Commission’s
Public Reference Room in Washington,
DC. There is an eSubscription link on
the website that enables subscribers to
receive email notification when a
document is added to a subscribed
E:\FR\FM\07NON1.SGM
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]]>Agencies
[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]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA
status; Relative
Common name Scientific name Stock \1\ strategic (Y/ Abundance PBR occurrence in
N) \2\ project area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Southern right whale............ Eubalaena australis n/a................ E/D; N 12,000 \3\......... N.A................ Uncommon.
3,300\5\...........
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Cetotheriidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy right whale............... Caperea marginata.. n/a................ .............. N.A................ N.A................ Rare.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale..................... Physeter n/a................ E 12,069 \10\........ N.A................ Uncommon.
macrocephalus.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Kogiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy sperm whale............... Kogia breviceps.... n/a................ .............. N.A................ N.A................ Rare.
Dwarf sperm whale............... Kogia sima......... n/a................ .............. N.A................ N.A................ Uncommon.
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
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
[[Page 60076]]
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
