Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil and Gas Activities in the Gulf of Mexico, 55790-55794 [2022-19597]
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TABLE 1—TAKE ANALYSIS—Continued
Authorized
take
Species
Clymene dolphin ..............................................................................................
Atlantic spotted dolphin ...................................................................................
Pantropical spotted dolphin .............................................................................
Spinner dolphin ................................................................................................
Striped dolphin .................................................................................................
Fraser’s dolphin ...............................................................................................
Risso’s dolphin .................................................................................................
Melon-headed whale .......................................................................................
Pygmy killer whale ...........................................................................................
False killer whale .............................................................................................
Killer whale ......................................................................................................
Short-finned pilot whale ...................................................................................
3,377
2,040
17,180
3,768
1,363
397
947
2,215
577
868
7
594
Scaled take 1
969.3
585.5
4,930.7
1,081.5
391.3
113.9
279.3
653.3
170.2
256.1
n/a
175.2
Abundance 2
Percent
abundance
11,895
74,785
102,361
25,114
5,229
1,665
3,764
7,003
2,126
3,204
267
1,981
8.1
0.8
4.8
4.3
7.5
6.8
7.4
9.3
8.0
8.0
2.6
8.8
1 Scalar ratios were applied to ‘‘Authorized Take’’ values as described at 86 FR 5322, 5404 (January 19, 2021) to derive scaled take numbers
shown here.
2 Best abundance estimate. For most taxa, the best abundance estimate for purposes of comparison with take estimates is considered here to
be the model-predicted abundance (Roberts et al., 2016). For those taxa where a density surface model predicting abundance by month was
produced, the maximum mean seasonal abundance was used. For those taxa where abundance is not predicted by month, only mean annual
abundance is available. For the killer whale, the larger estimated SAR abundance estimate is used.
3 Includes 32 takes by Level A harassment and 550 takes by Level B harassment. Scalar ratio is applied to takes by Level B harassment only;
small numbers determination made on basis of scaled Level B harassment take plus authorized Level A harassment take.
Based on the analysis contained
herein of WesternGeco’s proposed
survey activity described in its LOA
application and the anticipated take of
marine mammals, NMFS finds that
small numbers of marine mammals will
be taken relative to the affected species
or stock sizes and therefore is of no
more than small numbers.
Authorization
NMFS has determined that the level
of taking for this LOA request is
consistent with the findings made for
the total taking allowable under the
incidental take regulations and that the
amount of take authorized under the
LOA is of no more than small numbers.
Accordingly, we have issued an LOA to
WesternGeco authorizing the take of
marine mammals incidental to its
geophysical survey activity, as
described above.
Dated: September 7, 2022.
Catherine G. Marzin,
Deputy Director, Office of Protected
Resources, National Marine Fisheries Service.
[FR Doc. 2022–19611 Filed 9–9–22; 8:45 am]
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BILLING CODE 3510–22–P
DEPARTMENT OF COMMERCE
the contact listed below (see FOR
FURTHER INFORMATION CONTACT).
National Oceanic and Atmospheric
Administration
FOR FURTHER INFORMATION CONTACT:
[RTID 0648–XC318]
Taking and Importing Marine
Mammals; Taking Marine Mammals
Incidental to Geophysical Surveys
Related to Oil and Gas Activities in the
Gulf of Mexico
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice of issuance of Letter of
Authorization.
AGENCY:
In accordance with the
Marine Mammal Protection Act
(MMPA), as amended, its implementing
regulations, and NMFS’ MMPA
Regulations for Taking Marine
Mammals Incidental to Geophysical
Surveys Related to Oil and Gas
Activities in the Gulf of Mexico,
notification is hereby given that a Letter
of Authorization (LOA) has been issued
to Shell Offshore Inc. (Shell) for the take
of marine mammals incidental to
geophysical survey activity in the Gulf
of Mexico.
DATES: The LOA is effective from
October 1, 2022, through August 31,
2023.
SUMMARY:
The LOA, LOA request, and
supporting documentation are available
online at: www.fisheries.noaa.gov/
action/incidental-take-authorization-oiland-gas-industry-geophysical-surveyactivity-gulf-mexico. In case of problems
accessing these documents, please call
ADDRESSES:
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Laws, Office of Protected Resources,
NMFS, (301) 427–8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the
MMPA (16 U.S.C. 1361 et seq.) direct
the Secretary of Commerce 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
authorization is provided to the public
for review.
An authorization for incidental
takings shall be granted if NMFS finds
that the taking will have a negligible
impact on the species or stock(s), will
not have an unmitigable adverse impact
on the availability of the species or
stock(s) for subsistence uses (where
relevant), and if the permissible
methods of taking and requirements
pertaining to the mitigation, monitoring
and reporting of such takings are set
forth. NMFS has defined ‘‘negligible
impact’’ in 50 CFR 216.103 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.
Except with respect to certain
activities not pertinent here, the MMPA
defines ‘‘harassment’’ as: any act of
pursuit, torment, or annoyance which (i)
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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).
On January 19, 2021, we issued a final
rule with regulations to govern the
unintentional taking of marine
mammals incidental to geophysical
survey activities conducted by oil and
gas industry operators, and those
persons authorized to conduct activities
on their behalf (collectively ‘‘industry
operators’’), in Federal waters of the
U.S. Gulf of Mexico (GOM) over the
course of 5 years (86 FR 5322, January
19, 2021). The rule was based on our
findings that the total taking from the
specified activities over the 5-year
period will have a negligible impact on
the affected species or stock(s) of marine
mammals and will not have an
unmitigable adverse impact on the
availability of those species or stocks for
subsistence uses. The rule became
effective on April 19, 2021.
Our regulations at 50 CFR 217.180 et
seq. allow for the issuance of LOAs to
industry operators for the incidental
take of marine mammals during
geophysical survey activities and
prescribe the permissible methods of
taking and other means of effecting the
least practicable adverse impact on
marine mammal species or stocks and
their habitat (often referred to as
mitigation), as well as requirements
pertaining to the monitoring and
reporting of such taking. Under 50 CFR
217.186(e), issuance of an LOA shall be
based on a determination that the level
of taking will be consistent with the
findings made for the total taking
allowable under these regulations and a
determination that the amount of take
authorized under the LOA is of no more
than small numbers.
Summary of Request and Analysis
Shell plans to conduct a 3D ocean
bottom node (OBN) survey in Garden
Banks Lease Block GB555 and GB556
and the surrounding 414 lease blocks,
with approximate water depths ranging
from 150 to 1,975 meters (m). See
Section F of the LOA application for a
map of the area.
Shell anticipates using two dual
source vessels, towing either lowfrequency tuned pulse sources (TPS) or
conventional airgun array sources. Use
of the TPS is preferred by Shell, but the
airgun array sources may be used if the
TPS are not available, or if the TPSs fail
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during acquisition. The airgun array
sources would consist of 32 elements,
with a total volume of 5,110 cubic
inches (in3).
The TPS was not included in the
acoustic exposure modeling developed
in support of the rule. However, the rule
anticipated the possibility of new and
unusual technologies (NUT) and
determined they would be evaluated on
a case-by case basis (86 FR 5322, 5442,
January 19, 2021). This source has
previously been evaluated through the
NUT process as described in the notice
of issuance of a previous LOA to Shell
(86 FR 37309, July 15, 2021). Please see
that notice for additional discussion.
The TPS operates on the same basic
principles as a traditional airgun source
in that it uses compressed air to create
a bubble in the water column which
then goes through a series of collapses
and expansions creating primarily lowfrequency sounds. The difference
between the two sources is that the TPS
releases a larger volume of air (the TPS
planned for use here has a volume of
28,000 in3 per element, whereas the
standard airgun array used in the
acoustic exposure modeling supporting
the rule has a total volume of 8,000 in3),
but at lower pressure (the TPS operates
at 1,000 pounds per square inch (psi),
whereas traditional airguns are typically
operated at 2,000 psi). This creates a
larger bubble resulting in more of the
energy being concentrated in lowfrequencies. The release of the air is also
‘‘tuned’’ so that the primary signal has
an extended rise time and lower peak
pressure level than that of a traditional
airgun array source. The results of
initial acoustic modeling, quarry tests,
and field measurements of TPS sources
show the sounds produced have lower
peak pressures and less energy at higher
frequencies than conventional airgun
arrays. We discussed the results of
initial modeling and of acoustic tests
performed in a quarry in the
aforementioned notice of LOA issuance
(July 15, 2021, 86 FR 37309). During the
survey associated with that notice, field
measurements of a 26,500-in3 TPS were
obtained using a hydrophone recorder
on the seafloor at 2,830 m water depth
directly below the operating sources.
The newer data confirm that the TPS
produces more sound at lower
frequencies (approximately 2–4 Hertz
(Hz)) compared to an airgun source,
while producing much less sound
(lower decibel levels) at frequencies
above 4 Hz, meaning that the source
produces significantly reduced energy at
frequencies used by marine mammals
for hearing and communication. This
means that even for species in the lowfrequency hearing group (mysticete
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whales) most affected by seismic survey
sounds, the TPS is expected to have less
impact than a traditional airgun array in
terms of overlap with frequencies the
species use. Potential impacts on midand high-frequency hearing groups will
be reduced even more.
Besides producing less energy in
frequencies used by marine mammals,
the TPS produces sounds with overall
lower energy at the source. Test data for
the TPS were obtained at a quarry,
showing that the source produces
significantly less output than a
traditional airgun array at all
frequencies above 5 Hz. For example,
the measured source level (at the typical
reference distance of 1 m) has a peak
sound pressure level (SPLpeak) of 236
decibels (dB), approximately 19 dB less
than the modeled SPLpeak source level
for the 8,000-in3 airgun array used in the
acoustic exposure modeling. For every
6-dB reduction in source level, the
approximate distance to the same
threshold level would be cut in half,
meaning that there would be more than
an 8-fold reduction in distance to
SPLpeak thresholds. This reduction
would be even greater when considering
the actual 5,110-in3 airgun array that
may be used as a secondary option for
this planned survey, with SPLpeak source
level approximately 25 dB greater than
the TPS. The same relative reduction
would apply to root mean square SPL
threshold distances as well.
There would also be a significant
reduction in the likelihood that auditory
injury could result from the
accumulation of energy (which is
expected to dictate occurrence of injury
for low-frequency cetaceans). The much
lower peak sound pressure levels near
the source and extended rise time
reduce the potential for auditory injury
(Level A harassment) for all marine
mammal species, since these are the two
main physical characteristics of
impulsive sounds that are considered
most injurious.
The planned survey may use two
28,000-in3 TPS sources discharged
simultaneously, versus the single
26,500-in3 source measured during field
trials. The relative difference in output
between a single 28,000-in3 source and
single 26,500-in3 source is indicated by
the cube root of the ratio of the two
volumes, equating to an approximate 2
percent increase in source level.
Therefore, evaluation of the source
levels measured for the 26,500-in2
source is a reasonable approximation.
Adding a second source identical to the
first effectively doubles the combined
output resulting in a 6-dB increase in
the source level. Even with the
increased sound levels, the dual TPS
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source is anticipated to produce much
lower sound levels than a conventional
source array at all frequencies above
approximately 5 Hz.
These factors lead to a conclusion that
take by Level B harassment associated
with use of the TPS would be less than
would occur for a similar survey instead
using the modeled airgun array as a
sound source, and that use of the TPS
results in lower potential for the
occurrence of Level A harassment than
does use of the modeled airgun array.
Based on the foregoing, we have
determined there will be no effects of a
magnitude or intensity different from
those evaluated in support of the rule.
Moreover, use of modeling results
relating to use of the 72 element, 8,000in3 airgun array are expected to be
significantly conservative as a proxy for
use in evaluating potential impacts of
use of the TPS.
Consistent with the preamble to the
final rule, the survey effort proposed by
Shell in its LOA request was used to
develop LOA-specific take estimates
based on the acoustic exposure
modeling results described in the
preamble (86 FR 5398, January 19,
2021). In order to generate the
appropriate take numbers for
authorization, the following information
was considered: (1) survey type; (2)
location (by modeling zone 1); (3)
number of days; and (4) season.2 The
acoustic exposure modeling performed
in support of the rule provides 24-hour
exposure estimates for each species,
specific to each modeled survey type in
each zone and season.
No 3D OBN surveys were included in
the modeled survey types, and use of
existing proxies (i.e., 2D, 3D NAZ, 3D
WAZ, Coil) is generally conservative for
use in evaluation of 3D OBN survey
effort, largely due to the greater area
covered by the modeled proxies.
Summary descriptions of these modeled
survey geometries are available in the
preamble to the proposed rule (83 FR
29212, 29220, June 22, 2018). Coil was
selected as the best available proxy
survey type in this case because the
spatial coverage of the planned survey
is most similar to the coil survey
pattern. The planned 3D OBN survey
will involve two source vessels sailing
along survey lines ranging in length
from approximately 20–95 km in length.
The coil survey pattern was assumed to
cover approximately 144 kilometers
squared (km2) per day (compared with
1 For purposes of acoustic exposure modeling, the
GOM was divided into seven zones. Zone 1 is not
included in the geographic scope of the rule.
2 For purposes of acoustic exposure modeling,
seasons include Winter (December–March) and
Summer (April–November).
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approximately 795 km2, 199 km2, and
845 km2 per day for the 2D, 3D NAZ,
and 3D WAZ survey patterns,
respectively). Among the different
parameters of the modeled survey
patterns (e.g., area covered, line spacing,
number of sources, shot interval, total
simulated pulses), NMFS considers area
covered per day to be most influential
on daily modeled exposures exceeding
Level B harassment criteria. Although
Shell is not proposing to perform a
survey using the coil geometry, its
planned 3D OBN survey is expected to
cover approximately 140 km2 per day,
meaning that the coil proxy is most
representative of the effort planned by
Shell in terms of predicted Level B
harassment exposures.
In addition, all available acoustic
exposure modeling results assume use
of a 72-element, 8,000 in3 array. Thus,
estimated take numbers for this LOA are
considered conservative due to
differences between the acoustic source
planned for use (TPS or 32 element,
5,200 in3 airgun array) and the proxy
array modeled for the rule.
The survey will take place over
approximately 105 days, including 63
days of sound source operation, all
within Zone 5. The seasonal
distribution of survey days is not known
in advance. Therefore, the take
estimates for each species are based on
the season that produces the greater
value.
Additionally, for some species, take
estimates based solely on the modeling
yielded results that are not realistically
likely to occur when considered in light
of other relevant information available
during the rulemaking process regarding
marine mammal occurrence in the
GOM. The approach used in the
acoustic exposure modeling, in which
seven modeling zones were defined over
the U.S. GOM, necessarily averages finescale information about marine mammal
distribution over the large area of each
modeling zone. This can result in
unrealistic projections regarding the
likelihood of encountering particularly
rare species and/or species not expected
to occur outside particular habitats.
Thus, although the modeling conducted
for the rule is a natural starting point for
estimating take, our rule acknowledged
that other information could be
considered (see, e.g., 86 FR 5442
(January 19, 2021), discussing the need
to provide flexibility and make efficient
use of previous public and agency
review of other information and
identifying that additional public
review is not necessary unless the
model or inputs used differ
substantively from those that were
previously reviewed by NMFS and the
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public). For this survey, NMFS has
other relevant information reviewed
during the rulemaking that indicates use
of the acoustic exposure modeling to
generate a take estimate for certain
marine mammal species produces
results that are inconsistent with what
is known regarding their occurrence in
the GOM. Accordingly, we have
adjusted the calculated take estimates
for those species as described below.
Rice’s whales (formerly known as
GOM Bryde’s whales) 3 are mostly found
in a ‘‘core habitat area’’ located in the
northeastern GOM in waters between
100–400 m depth along the continental
shelf break (Rosel et al., 2016). (Note
that this core habitat area is outside the
scope of the rule.) However, whaling
records suggest that Rice’s whales
historically had a broader distribution
within similar habitat parameters
throughout the GOM (Reeves et al.,
2011; Rosel and Wilcox, 2014). In
addition, habitat-based density
modeling identified similar habitat (i.e.,
approximately 100–400 m water depths
along the continental shelf break) as
being potential Rice’s whale habitat
(Roberts et al., 2016), although the core
habitat area contained approximately 92
percent of the predicted abundance of
Rice’s whales. See discussion provided
at, e.g., 83 FR 29228, 83 FR 29280 (June
22, 2018); 86 FR 5418 (January 19,
2021).
There are few data on Rice’s whale
occurrence outside of the northeastern
GOM core habitat area. There were two
sightings of unidentified large baleen
whales (recorded as Balaenoptera sp. or
Bryde’s/sei whale) in 1992 in the
western GOM during systematic survey
effort and, more recently, a NOAA
survey reported observation of a Rice’s
whale in the western GOM in 2017
(NMFS, 2018). There were five potential
sightings of Rice’s whales by protected
species observers (PSOs) aboard
industry geophysical survey vessels
west of New Orleans from 2010–2014,
all within the 200–400 m isobaths
(Rosel et al., 2021). In addition,
sporadic, year-round recordings of
Rice’s whale calls were made south of
Louisiana within approximately the
same depth range between 2016 and
2017 (Soldevilla et al., 2022).
Although Rice’s whales may occur
outside of the core habitat area, we
expect that any such occurrence would
be limited to the narrow band of
suitable habitat described above (i.e.,
100–400 m) and that, based on the few
3 The final rule refers to the GOM Bryde’s whale
(Balaenoptera edeni). These whales were
subsequently described as a new species, Rice’s
whale (Balaenoptera ricei) (Rosel et al., 2021).
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available records, these occurrences
would be rare. Shell’s planned activities
will overlap this depth range, with
approximately 18 percent of the area
expected to be ensonified by the survey
above root-mean-squared pressure
received levels (RMS SPL) of 160 dB
(referenced to 1 micropascal (re 1 mPa))
overlapping the 100–400 m isobaths.
Therefore, while we expect take of
Rice’s whale to be unlikely, there is
some reasonable potential for take of
Rice’s whale to occur in association
with this survey. However, NMFS’
determination in reflection of the data
discussed above, which informed the
final rule, is that use of the generic
acoustic exposure modeling results for
Rice’s whales would result in estimated
take numbers that are inconsistent with
the assumptions made in the rule
regarding expected Rice’s whale take (86
FR 5322, 5403; January 19, 2021).
Killer whales are the most rarely
encountered species in the GOM,
typically in deep waters of the central
GOM (Roberts et al., 2015; Maze-Foley
and Mullin, 2006). As discussed in the
final rule, the density models produced
by Roberts et al. (2016) provide the best
available scientific information
regarding predicted density patterns of
cetaceans in the U.S. GOM. The
predictions represent the output of
models derived from multi-year
observations and associated
environmental parameters that
incorporate corrections for detection
bias. However, in the case of killer
whales, the model is informed by few
data, as indicated by the coefficient of
variation associated with the abundance
predicted by the model (0.41, the
second-highest of any GOM species
model; Roberts et al., 2016). The
model’s authors noted the expected
non-uniform distribution of this rarelyencountered species and expressed that,
due to the limited data available to
inform the model, it ‘‘should be viewed
cautiously’’ (Roberts et al., 2015).
NOAA surveys in the GOM from
1992–2009 reported only 16 sightings of
killer whales, with an additional three
encounters during more recent survey
effort from 2017–18 (Waring et al., 2013;
www.boem.gov/gommapps). Two other
species were also observed on less than
20 occasions during the 1992–2009
NOAA surveys (Fraser’s dolphin and
false killer whale 4). However,
observational data collected by PSOs on
industry geophysical survey vessels
from 2002–2015 distinguish the killer
whale in terms of rarity. During this
4 However, note that these species have been
observed over a greater range of water depths in the
GOM than have killer whales.
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period, killer whales were encountered
on only 10 occasions, whereas the next
most rarely encountered species
(Fraser’s dolphin) was recorded on 69
occasions (Barkaszi and Kelly, 2019).
The false killer whale and pygmy killer
whale were the next most rarely
encountered species, with 110 records
each. The killer whale was the species
with the lowest detection frequency
during each period over which PSO data
were synthesized (2002–2008 and 2009–
2015). This information qualitatively
informed our rulemaking process, as
discussed at 86 FR 5334 (January 19,
2021), and similarly informs our
analysis here.
The rarity of encounter during seismic
surveys is not likely to be the product
of high bias on the probability of
detection. Unlike certain cryptic species
with high detection bias, such as Kogia
spp. or beaked whales, or deep-diving
species with high availability bias, such
as beaked whales or sperm whales,
killer whales are typically available for
detection when present and are easily
observed. Roberts et al. (2015) stated
that availability is not a major factor
affecting detectability of killer whales
from shipboard surveys, as they are not
a particularly long-diving species. Baird
et al. (2005) reported that mean dive
durations for 41 fish-eating killer whales
for dives greater than or equal to 1
minute in duration was 2.3–2.4 minutes,
and Hooker et al. (2012) reported that
killer whales spent 78 percent of their
time at depths between 0–10 m.
Similarly, Kvadsheim et al. (2012)
reported data from a study of four killer
whales, noting that the whales
performed 20 times as many dives to 1–
30 m depth than to deeper waters, with
an average depth during those most
common dives of approximately 3 m.
In summary, killer whales are the
most rarely encountered species in the
GOM and typically occur only in
particularly deep water. While this
information is reflected through the
density model informing the acoustic
exposure modeling results, there is
relatively high uncertainty associated
with the model for this species, and the
acoustic exposure modeling applies
mean distribution data over areas where
the species is in fact less likely to occur.
In addition, as noted above in relation
to the general take estimation
methodology, the assumed proxy source
(72-element, 8,000-in3 array) results in a
significant overestimate of the actual
potential for take to occur. NMFS’
determination in reflection of the
information discussed above, which
informed the final rule, is that use of the
generic acoustic exposure modeling
results for killer whales for this survey
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would result in estimated take numbers
that are inconsistent with the
assumptions made in the rule regarding
expected killer whale take (86 FR 5403,
January 19, 2021).
In past authorizations, NMFS has
often addressed situations involving the
low likelihood of encountering a rare
species such as Rice’s whales or killer
whales in the GOM through
authorization of take of a single group
of average size (i.e., representing a
single potential encounter). See 83 FR
63268, December 7, 2018. See also 86
FR 29090, May 28, 2021 and 85 FR
55645, September 9, 2020. For the
reasons expressed above, NMFS
determined that a single encounter of
Rice’s whales or killer whales is more
likely than the model-generated
estimates and has authorized take
associated with a single group
encounter (i.e., up to 2 and 7 animals,
respectively).
Based on the results of our analysis,
NMFS has determined that the level of
taking authorized through the LOA is
consistent with the findings made for
the total taking allowable under the
regulations for the affected species or
stocks of marine mammals. See Table 1
in this notice and Table 9 of the rule (86
FR 5322, January 19, 2021).
Small Numbers Determination
Under the GOM rule, NMFS may not
authorize incidental take of marine
mammals in an LOA if it will exceed
‘‘small numbers.’’ In short, when an
acceptable estimate of the individual
marine mammals taken is available, if
the estimated number of individual
animals taken is up to, but not greater
than, one-third of the best available
abundance estimate, NMFS will
determine that the numbers of marine
mammals taken of a species or stock are
small. For more information please see
NMFS’ discussion of the MMPA’s small
numbers requirement provided in the
final rule (86 FR 5438, January 19,
2021).
The take numbers for authorization
are determined as described above in
the Summary of Request and Analysis
section. Subsequently, the total
incidents of harassment for each species
are multiplied by scalar ratios to
produce a derived product that better
reflects the number of individuals likely
to be taken within a survey (as
compared to the total number of
instances of take), accounting for the
likelihood that some individual marine
mammals may be taken on more than
one day (see 86 FR 5404, January 19,
2021). The output of this scaling, where
appropriate, is incorporated into
adjusted total take estimates that are the
E:\FR\FM\12SEN1.SGM
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Federal Register / Vol. 87, No. 175 / Monday, September 12, 2022 / Notices
basis for NMFS’ small numbers
determinations, as depicted in Table 1.
This product is used by NMFS in
making the necessary small numbers
determinations through comparison
with the best available abundance
estimates (see discussion at 86 FR 5391,
January 19, 2021). For this comparison,
NMFS’ approach is to use the maximum
theoretical population, determined
through review of current stock
assessment reports (SAR;
www.fisheries.noaa.gov/national/
marine-mammal-protection/marinemammal-stock-assessments) and modelpredicted abundance information
(https://seamap.env.duke.edu/models/
Duke/GOM/). For the latter, for taxa
where a density surface model could be
produced, we use the maximum mean
seasonal (i.e., 3-month) abundance
prediction for purposes of comparison
as a precautionary smoothing of monthto-month fluctuations and in
consideration of a corresponding lack of
data in the literature regarding seasonal
distribution of marine mammals in the
GOM. Information supporting the small
numbers determinations is provided in
Table 1.
TABLE 1—TAKE ANALYSIS
Authorized
take
Species
Rice’s whale .....................................................................................................
Sperm whale ....................................................................................................
Kogia spp .........................................................................................................
Beaked whales ................................................................................................
Rough-toothed dolphin ....................................................................................
Bottlenose dolphin ...........................................................................................
Clymene dolphin ..............................................................................................
Atlantic spotted dolphin ...................................................................................
Pantropical spotted dolphin .............................................................................
Spinner dolphin ................................................................................................
Striped dolphin .................................................................................................
Fraser’s dolphin ...............................................................................................
Risso’s dolphin .................................................................................................
Melon-headed whale .......................................................................................
Pygmy killer whale ...........................................................................................
False killer whale .............................................................................................
Killer whale ......................................................................................................
Short-finned pilot whale ...................................................................................
2
1,657
3 626
7,314
1,258
5,959
3,539
2,380
16,058
4,303
1,382
397
1,040
2,325
547
870
7
673
Scaled take 1
n/a
700.9
190.4
738.7
360.9
1,710.1
1,015.6
683.1
4,608.7
1,234.9
396.7
114.0
306.7
685.9
161.4
256.8
n/a
198.4
Abundance 2
51
2,207
4,373
3,768
4,853
176,108
11,895
74,785
102,361
25,114
5,229
1,665
3,764
7,003
2,126
3,204
267
1,981
Percent
abundance
3.9
31.8
5.1
19.6
7.4
1.0
8.5
0.9
4.5
4.9
7.6
6.8
8.1
9.8
7.6
8.0
2.6
10.0
lotter on DSK11XQN23PROD with NOTICES1
1 Scalar ratios were applied to ‘‘Authorized Take’’ values as described at 86 FR 5322, 5404 (January 19, 2021) to derive scaled take numbers
shown here.
2 Best abundance estimate. For most taxa, the best abundance estimate for purposes of comparison with take estimates is considered here to
be the model-predicted abundance (Roberts et al., 2016). For those taxa where a density surface model predicting abundance by month was
produced, the maximum mean seasonal abundance was used. For those taxa where abundance is not predicted by month, only mean annual
abundance is available. For Rice’s whale and killer whale, the larger estimated SAR abundance estimate is used.
3 Includes 33 takes by Level A harassment and 593 takes by Level B harassment. Scalar ratio is applied to takes by Level B harassment only;
small numbers determination made on basis of scaled Level B harassment take plus authorized Level A harassment take.
Based on the analysis contained
herein of Shell’s proposed survey
activity described in its LOA
application and the anticipated take of
marine mammals, NMFS finds that
small numbers of marine mammals will
be taken relative to the affected species
or stock sizes and therefore is of no
more than small numbers.
Dated: September 6, 2022.
Catherine G. Marzin,
Deputy Director, Office of Protected
Resources, National Marine Fisheries Service.
Authorization
National Oceanic and Atmospheric
Administration
NMFS has determined that the level
of taking for this LOA request is
consistent with the findings made for
the total taking allowable under the
incidental take regulations and that the
amount of take authorized under the
LOA is of no more than small numbers.
Accordingly, we have issued an LOA to
Shell authorizing the take of marine
mammals incidental to its geophysical
survey activity, as described above.
[FR Doc. 2022–19597 Filed 9–9–22; 8:45 am]
The meeting will be held Friday,
September 30, 2022, from 10 a.m. to 4
p.m. Pacific daylight time or until
business for the day has been
completed.
BILLING CODE 3510–22–P
ADDRESSES:
DEPARTMENT OF COMMERCE
[RTID 0648–XC316]
Pacific Fishery Management Council;
Public Meeting
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
AGENCY:
ACTION:
Notice of public meetings.
The Pacific Fishery
Management Council’s (Pacific Council)
Ad Hoc Marine Planning Committee
(MPC) will hold a public meeting.
SUMMARY:
VerDate Sep<11>2014
17:06 Sep 09, 2022
Jkt 256001
PO 00000
Frm 00016
Fmt 4703
Sfmt 4703
DATES:
This meeting will be held
online. Specific meeting information,
including directions on how to join the
meeting and system requirements will
be provided in the meeting
announcement on the Pacific Council’s
website (see www.pcouncil.org). You
may send an email to Mr. Kris
Kleinschmidt (kris.kleinschmidt@
noaa.gov) or contact him at (503) 820–
2412 for technical assistance.
Council address: Pacific Fishery
Management Council, 7700 NE
Ambassador Place, Suite 101, Portland,
OR 97220–1384.
FOR FURTHER INFORMATION CONTACT:
Kerry Griffin, Staff Officer, Pacific
Council; telephone: (503) 820–2409.
SUPPLEMENTARY INFORMATION: The
primary purpose of this online meeting
is for the MPC to discuss issues related
to offshore wind energy development
E:\FR\FM\12SEN1.SGM
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Agencies
[Federal Register Volume 87, Number 175 (Monday, September 12, 2022)]
[Notices]
[Pages 55790-55794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-19597]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC318]
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to Geophysical Surveys Related to Oil and Gas Activities in
the Gulf of Mexico
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of issuance of Letter of Authorization.
-----------------------------------------------------------------------
SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA), as
amended, its implementing regulations, and NMFS' MMPA Regulations for
Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil
and Gas Activities in the Gulf of Mexico, notification is hereby given
that a Letter of Authorization (LOA) has been issued to Shell Offshore
Inc. (Shell) for the take of marine mammals incidental to geophysical
survey activity in the Gulf of Mexico.
DATES: The LOA is effective from October 1, 2022, through August 31,
2023.
ADDRESSES: The LOA, LOA request, and supporting documentation are
available online at: www.fisheries.noaa.gov/action/incidental-take-authorization-oil-and-gas-industry-geophysical-survey-activity-gulf-mexico. In case of problems accessing these documents, please call the
contact listed below (see FOR FURTHER INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce 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 authorization is
provided to the public for review.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
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.
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: any act of pursuit, torment, or
annoyance which (i)
[[Page 55791]]
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).
On January 19, 2021, we issued a final rule with regulations to
govern the unintentional taking of marine mammals incidental to
geophysical survey activities conducted by oil and gas industry
operators, and those persons authorized to conduct activities on their
behalf (collectively ``industry operators''), in Federal waters of the
U.S. Gulf of Mexico (GOM) over the course of 5 years (86 FR 5322,
January 19, 2021). The rule was based on our findings that the total
taking from the specified activities over the 5-year period will have a
negligible impact on the affected species or stock(s) of marine mammals
and will not have an unmitigable adverse impact on the availability of
those species or stocks for subsistence uses. The rule became effective
on April 19, 2021.
Our regulations at 50 CFR 217.180 et seq. allow for the issuance of
LOAs to industry operators for the incidental take of marine mammals
during geophysical survey activities and prescribe the permissible
methods of taking and other means of effecting the least practicable
adverse impact on marine mammal species or stocks and their habitat
(often referred to as mitigation), as well as requirements pertaining
to the monitoring and reporting of such taking. Under 50 CFR
217.186(e), issuance of an LOA shall be based on a determination that
the level of taking will be consistent with the findings made for the
total taking allowable under these regulations and a determination that
the amount of take authorized under the LOA is of no more than small
numbers.
Summary of Request and Analysis
Shell plans to conduct a 3D ocean bottom node (OBN) survey in
Garden Banks Lease Block GB555 and GB556 and the surrounding 414 lease
blocks, with approximate water depths ranging from 150 to 1,975 meters
(m). See Section F of the LOA application for a map of the area.
Shell anticipates using two dual source vessels, towing either low-
frequency tuned pulse sources (TPS) or conventional airgun array
sources. Use of the TPS is preferred by Shell, but the airgun array
sources may be used if the TPS are not available, or if the TPSs fail
during acquisition. The airgun array sources would consist of 32
elements, with a total volume of 5,110 cubic inches (in\3\).
The TPS was not included in the acoustic exposure modeling
developed in support of the rule. However, the rule anticipated the
possibility of new and unusual technologies (NUT) and determined they
would be evaluated on a case-by case basis (86 FR 5322, 5442, January
19, 2021). This source has previously been evaluated through the NUT
process as described in the notice of issuance of a previous LOA to
Shell (86 FR 37309, July 15, 2021). Please see that notice for
additional discussion.
The TPS operates on the same basic principles as a traditional
airgun source in that it uses compressed air to create a bubble in the
water column which then goes through a series of collapses and
expansions creating primarily low-frequency sounds. The difference
between the two sources is that the TPS releases a larger volume of air
(the TPS planned for use here has a volume of 28,000 in\3\ per element,
whereas the standard airgun array used in the acoustic exposure
modeling supporting the rule has a total volume of 8,000 in\3\), but at
lower pressure (the TPS operates at 1,000 pounds per square inch (psi),
whereas traditional airguns are typically operated at 2,000 psi). This
creates a larger bubble resulting in more of the energy being
concentrated in low-frequencies. The release of the air is also
``tuned'' so that the primary signal has an extended rise time and
lower peak pressure level than that of a traditional airgun array
source. The results of initial acoustic modeling, quarry tests, and
field measurements of TPS sources show the sounds produced have lower
peak pressures and less energy at higher frequencies than conventional
airgun arrays. We discussed the results of initial modeling and of
acoustic tests performed in a quarry in the aforementioned notice of
LOA issuance (July 15, 2021, 86 FR 37309). During the survey associated
with that notice, field measurements of a 26,500-in\3\ TPS were
obtained using a hydrophone recorder on the seafloor at 2,830 m water
depth directly below the operating sources.
The newer data confirm that the TPS produces more sound at lower
frequencies (approximately 2-4 Hertz (Hz)) compared to an airgun
source, while producing much less sound (lower decibel levels) at
frequencies above 4 Hz, meaning that the source produces significantly
reduced energy at frequencies used by marine mammals for hearing and
communication. This means that even for species in the low-frequency
hearing group (mysticete whales) most affected by seismic survey
sounds, the TPS is expected to have less impact than a traditional
airgun array in terms of overlap with frequencies the species use.
Potential impacts on mid- and high-frequency hearing groups will be
reduced even more.
Besides producing less energy in frequencies used by marine
mammals, the TPS produces sounds with overall lower energy at the
source. Test data for the TPS were obtained at a quarry, showing that
the source produces significantly less output than a traditional airgun
array at all frequencies above 5 Hz. For example, the measured source
level (at the typical reference distance of 1 m) has a peak sound
pressure level (SPLpeak) of 236 decibels (dB), approximately
19 dB less than the modeled SPLpeak source level for the
8,000-in\3\ airgun array used in the acoustic exposure modeling. For
every 6-dB reduction in source level, the approximate distance to the
same threshold level would be cut in half, meaning that there would be
more than an 8-fold reduction in distance to SPLpeak
thresholds. This reduction would be even greater when considering the
actual 5,110-in\3\ airgun array that may be used as a secondary option
for this planned survey, with SPLpeak source level
approximately 25 dB greater than the TPS. The same relative reduction
would apply to root mean square SPL threshold distances as well.
There would also be a significant reduction in the likelihood that
auditory injury could result from the accumulation of energy (which is
expected to dictate occurrence of injury for low-frequency cetaceans).
The much lower peak sound pressure levels near the source and extended
rise time reduce the potential for auditory injury (Level A harassment)
for all marine mammal species, since these are the two main physical
characteristics of impulsive sounds that are considered most injurious.
The planned survey may use two 28,000-in\3\ TPS sources discharged
simultaneously, versus the single 26,500-in\3\ source measured during
field trials. The relative difference in output between a single
28,000-in\3\ source and single 26,500-in\3\ source is indicated by the
cube root of the ratio of the two volumes, equating to an approximate 2
percent increase in source level. Therefore, evaluation of the source
levels measured for the 26,500-in\2\ source is a reasonable
approximation. Adding a second source identical to the first
effectively doubles the combined output resulting in a 6-dB increase in
the source level. Even with the increased sound levels, the dual TPS
[[Page 55792]]
source is anticipated to produce much lower sound levels than a
conventional source array at all frequencies above approximately 5 Hz.
These factors lead to a conclusion that take by Level B harassment
associated with use of the TPS would be less than would occur for a
similar survey instead using the modeled airgun array as a sound
source, and that use of the TPS results in lower potential for the
occurrence of Level A harassment than does use of the modeled airgun
array. Based on the foregoing, we have determined there will be no
effects of a magnitude or intensity different from those evaluated in
support of the rule. Moreover, use of modeling results relating to use
of the 72 element, 8,000-in\3\ airgun array are expected to be
significantly conservative as a proxy for use in evaluating potential
impacts of use of the TPS.
Consistent with the preamble to the final rule, the survey effort
proposed by Shell in its LOA request was used to develop LOA-specific
take estimates based on the acoustic exposure modeling results
described in the preamble (86 FR 5398, January 19, 2021). In order to
generate the appropriate take numbers for authorization, the following
information was considered: (1) survey type; (2) location (by modeling
zone \1\); (3) number of days; and (4) season.\2\ The acoustic exposure
modeling performed in support of the rule provides 24-hour exposure
estimates for each species, specific to each modeled survey type in
each zone and season.
---------------------------------------------------------------------------
\1\ For purposes of acoustic exposure modeling, the GOM was
divided into seven zones. Zone 1 is not included in the geographic
scope of the rule.
\2\ For purposes of acoustic exposure modeling, seasons include
Winter (December-March) and Summer (April-November).
---------------------------------------------------------------------------
No 3D OBN surveys were included in the modeled survey types, and
use of existing proxies (i.e., 2D, 3D NAZ, 3D WAZ, Coil) is generally
conservative for use in evaluation of 3D OBN survey effort, largely due
to the greater area covered by the modeled proxies. Summary
descriptions of these modeled survey geometries are available in the
preamble to the proposed rule (83 FR 29212, 29220, June 22, 2018). Coil
was selected as the best available proxy survey type in this case
because the spatial coverage of the planned survey is most similar to
the coil survey pattern. The planned 3D OBN survey will involve two
source vessels sailing along survey lines ranging in length from
approximately 20-95 km in length. The coil survey pattern was assumed
to cover approximately 144 kilometers squared (km\2\) per day (compared
with approximately 795 km\2\, 199 km\2\, and 845 km\2\ per day for the
2D, 3D NAZ, and 3D WAZ survey patterns, respectively). Among the
different parameters of the modeled survey patterns (e.g., area
covered, line spacing, number of sources, shot interval, total
simulated pulses), NMFS considers area covered per day to be most
influential on daily modeled exposures exceeding Level B harassment
criteria. Although Shell is not proposing to perform a survey using the
coil geometry, its planned 3D OBN survey is expected to cover
approximately 140 km\2\ per day, meaning that the coil proxy is most
representative of the effort planned by Shell in terms of predicted
Level B harassment exposures.
In addition, all available acoustic exposure modeling results
assume use of a 72-element, 8,000 in\3\ array. Thus, estimated take
numbers for this LOA are considered conservative due to differences
between the acoustic source planned for use (TPS or 32 element, 5,200
in\3\ airgun array) and the proxy array modeled for the rule.
The survey will take place over approximately 105 days, including
63 days of sound source operation, all within Zone 5. The seasonal
distribution of survey days is not known in advance. Therefore, the
take estimates for each species are based on the season that produces
the greater value.
Additionally, for some species, take estimates based solely on the
modeling yielded results that are not realistically likely to occur
when considered in light of other relevant information available during
the rulemaking process regarding marine mammal occurrence in the GOM.
The approach used in the acoustic exposure modeling, in which seven
modeling zones were defined over the U.S. GOM, necessarily averages
fine-scale information about marine mammal distribution over the large
area of each modeling zone. This can result in unrealistic projections
regarding the likelihood of encountering particularly rare species and/
or species not expected to occur outside particular habitats. Thus,
although the modeling conducted for the rule is a natural starting
point for estimating take, our rule acknowledged that other information
could be considered (see, e.g., 86 FR 5442 (January 19, 2021),
discussing the need to provide flexibility and make efficient use of
previous public and agency review of other information and identifying
that additional public review is not necessary unless the model or
inputs used differ substantively from those that were previously
reviewed by NMFS and the public). For this survey, NMFS has other
relevant information reviewed during the rulemaking that indicates use
of the acoustic exposure modeling to generate a take estimate for
certain marine mammal species produces results that are inconsistent
with what is known regarding their occurrence in the GOM. Accordingly,
we have adjusted the calculated take estimates for those species as
described below.
Rice's whales (formerly known as GOM Bryde's whales) \3\ are mostly
found in a ``core habitat area'' located in the northeastern GOM in
waters between 100-400 m depth along the continental shelf break (Rosel
et al., 2016). (Note that this core habitat area is outside the scope
of the rule.) However, whaling records suggest that Rice's whales
historically had a broader distribution within similar habitat
parameters throughout the GOM (Reeves et al., 2011; Rosel and Wilcox,
2014). In addition, habitat-based density modeling identified similar
habitat (i.e., approximately 100-400 m water depths along the
continental shelf break) as being potential Rice's whale habitat
(Roberts et al., 2016), although the core habitat area contained
approximately 92 percent of the predicted abundance of Rice's whales.
See discussion provided at, e.g., 83 FR 29228, 83 FR 29280 (June 22,
2018); 86 FR 5418 (January 19, 2021).
---------------------------------------------------------------------------
\3\ The final rule refers to the GOM Bryde's whale (Balaenoptera
edeni). These whales were subsequently described as a new species,
Rice's whale (Balaenoptera ricei) (Rosel et al., 2021).
---------------------------------------------------------------------------
There are few data on Rice's whale occurrence outside of the
northeastern GOM core habitat area. There were two sightings of
unidentified large baleen whales (recorded as Balaenoptera sp. or
Bryde's/sei whale) in 1992 in the western GOM during systematic survey
effort and, more recently, a NOAA survey reported observation of a
Rice's whale in the western GOM in 2017 (NMFS, 2018). There were five
potential sightings of Rice's whales by protected species observers
(PSOs) aboard industry geophysical survey vessels west of New Orleans
from 2010-2014, all within the 200-400 m isobaths (Rosel et al., 2021).
In addition, sporadic, year-round recordings of Rice's whale calls were
made south of Louisiana within approximately the same depth range
between 2016 and 2017 (Soldevilla et al., 2022).
Although Rice's whales may occur outside of the core habitat area,
we expect that any such occurrence would be limited to the narrow band
of suitable habitat described above (i.e., 100-400 m) and that, based
on the few
[[Page 55793]]
available records, these occurrences would be rare. Shell's planned
activities will overlap this depth range, with approximately 18 percent
of the area expected to be ensonified by the survey above root-mean-
squared pressure received levels (RMS SPL) of 160 dB (referenced to 1
micropascal (re 1 [mu]Pa)) overlapping the 100-400 m isobaths.
Therefore, while we expect take of Rice's whale to be unlikely, there
is some reasonable potential for take of Rice's whale to occur in
association with this survey. However, NMFS' determination in
reflection of the data discussed above, which informed the final rule,
is that use of the generic acoustic exposure modeling results for
Rice's whales would result in estimated take numbers that are
inconsistent with the assumptions made in the rule regarding expected
Rice's whale take (86 FR 5322, 5403; January 19, 2021).
Killer whales are the most rarely encountered species in the GOM,
typically in deep waters of the central GOM (Roberts et al., 2015;
Maze-Foley and Mullin, 2006). As discussed in the final rule, the
density models produced by Roberts et al. (2016) provide the best
available scientific information regarding predicted density patterns
of cetaceans in the U.S. GOM. The predictions represent the output of
models derived from multi-year observations and associated
environmental parameters that incorporate corrections for detection
bias. However, in the case of killer whales, the model is informed by
few data, as indicated by the coefficient of variation associated with
the abundance predicted by the model (0.41, the second-highest of any
GOM species model; Roberts et al., 2016). The model's authors noted the
expected non-uniform distribution of this rarely-encountered species
and expressed that, due to the limited data available to inform the
model, it ``should be viewed cautiously'' (Roberts et al., 2015).
NOAA surveys in the GOM from 1992-2009 reported only 16 sightings
of killer whales, with an additional three encounters during more
recent survey effort from 2017-18 (Waring et al., 2013; www.boem.gov/gommapps). Two other species were also observed on less than 20
occasions during the 1992-2009 NOAA surveys (Fraser's dolphin and false
killer whale \4\). However, observational data collected by PSOs on
industry geophysical survey vessels from 2002-2015 distinguish the
killer whale in terms of rarity. During this period, killer whales were
encountered on only 10 occasions, whereas the next most rarely
encountered species (Fraser's dolphin) was recorded on 69 occasions
(Barkaszi and Kelly, 2019). The false killer whale and pygmy killer
whale were the next most rarely encountered species, with 110 records
each. The killer whale was the species with the lowest detection
frequency during each period over which PSO data were synthesized
(2002-2008 and 2009-2015). This information qualitatively informed our
rulemaking process, as discussed at 86 FR 5334 (January 19, 2021), and
similarly informs our analysis here.
---------------------------------------------------------------------------
\4\ However, note that these species have been observed over a
greater range of water depths in the GOM than have killer whales.
---------------------------------------------------------------------------
The rarity of encounter during seismic surveys is not likely to be
the product of high bias on the probability of detection. Unlike
certain cryptic species with high detection bias, such as Kogia spp. or
beaked whales, or deep-diving species with high availability bias, such
as beaked whales or sperm whales, killer whales are typically available
for detection when present and are easily observed. Roberts et al.
(2015) stated that availability is not a major factor affecting
detectability of killer whales from shipboard surveys, as they are not
a particularly long-diving species. Baird et al. (2005) reported that
mean dive durations for 41 fish-eating killer whales for dives greater
than or equal to 1 minute in duration was 2.3-2.4 minutes, and Hooker
et al. (2012) reported that killer whales spent 78 percent of their
time at depths between 0-10 m. Similarly, Kvadsheim et al. (2012)
reported data from a study of four killer whales, noting that the
whales performed 20 times as many dives to 1-30 m depth than to deeper
waters, with an average depth during those most common dives of
approximately 3 m.
In summary, killer whales are the most rarely encountered species
in the GOM and typically occur only in particularly deep water. While
this information is reflected through the density model informing the
acoustic exposure modeling results, there is relatively high
uncertainty associated with the model for this species, and the
acoustic exposure modeling applies mean distribution data over areas
where the species is in fact less likely to occur. In addition, as
noted above in relation to the general take estimation methodology, the
assumed proxy source (72-element, 8,000-in\3\ array) results in a
significant overestimate of the actual potential for take to occur.
NMFS' determination in reflection of the information discussed above,
which informed the final rule, is that use of the generic acoustic
exposure modeling results for killer whales for this survey would
result in estimated take numbers that are inconsistent with the
assumptions made in the rule regarding expected killer whale take (86
FR 5403, January 19, 2021).
In past authorizations, NMFS has often addressed situations
involving the low likelihood of encountering a rare species such as
Rice's whales or killer whales in the GOM through authorization of take
of a single group of average size (i.e., representing a single
potential encounter). See 83 FR 63268, December 7, 2018. See also 86 FR
29090, May 28, 2021 and 85 FR 55645, September 9, 2020. For the reasons
expressed above, NMFS determined that a single encounter of Rice's
whales or killer whales is more likely than the model-generated
estimates and has authorized take associated with a single group
encounter (i.e., up to 2 and 7 animals, respectively).
Based on the results of our analysis, NMFS has determined that the
level of taking authorized through the LOA is consistent with the
findings made for the total taking allowable under the regulations for
the affected species or stocks of marine mammals. See Table 1 in this
notice and Table 9 of the rule (86 FR 5322, January 19, 2021).
Small Numbers Determination
Under the GOM rule, NMFS may not authorize incidental take of
marine mammals in an LOA if it will exceed ``small numbers.'' In short,
when an acceptable estimate of the individual marine mammals taken is
available, if the estimated number of individual animals taken is up
to, but not greater than, one-third of the best available abundance
estimate, NMFS will determine that the numbers of marine mammals taken
of a species or stock are small. For more information please see NMFS'
discussion of the MMPA's small numbers requirement provided in the
final rule (86 FR 5438, January 19, 2021).
The take numbers for authorization are determined as described
above in the Summary of Request and Analysis section. Subsequently, the
total incidents of harassment for each species are multiplied by scalar
ratios to produce a derived product that better reflects the number of
individuals likely to be taken within a survey (as compared to the
total number of instances of take), accounting for the likelihood that
some individual marine mammals may be taken on more than one day (see
86 FR 5404, January 19, 2021). The output of this scaling, where
appropriate, is incorporated into adjusted total take estimates that
are the
[[Page 55794]]
basis for NMFS' small numbers determinations, as depicted in Table 1.
This product is used by NMFS in making the necessary small numbers
determinations through comparison with the best available abundance
estimates (see discussion at 86 FR 5391, January 19, 2021). For this
comparison, NMFS' approach is to use the maximum theoretical
population, determined through review of current stock assessment
reports (SAR; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and model-predicted abundance
information (https://seamap.env.duke.edu/models/Duke/GOM/). For the
latter, for taxa where a density surface model could be produced, we
use the maximum mean seasonal (i.e., 3-month) abundance prediction for
purposes of comparison as a precautionary smoothing of month-to-month
fluctuations and in consideration of a corresponding lack of data in
the literature regarding seasonal distribution of marine mammals in the
GOM. Information supporting the small numbers determinations is
provided in Table 1.
Table 1--Take Analysis
----------------------------------------------------------------------------------------------------------------
Authorized Scaled take Percent
Species take \1\ Abundance \2\ abundance
----------------------------------------------------------------------------------------------------------------
Rice's whale.................................... 2 n/a 51 3.9
Sperm whale..................................... 1,657 700.9 2,207 31.8
Kogia spp....................................... \3\ 626 190.4 4,373 5.1
Beaked whales................................... 7,314 738.7 3,768 19.6
Rough-toothed dolphin........................... 1,258 360.9 4,853 7.4
Bottlenose dolphin.............................. 5,959 1,710.1 176,108 1.0
Clymene dolphin................................. 3,539 1,015.6 11,895 8.5
Atlantic spotted dolphin........................ 2,380 683.1 74,785 0.9
Pantropical spotted dolphin..................... 16,058 4,608.7 102,361 4.5
Spinner dolphin................................. 4,303 1,234.9 25,114 4.9
Striped dolphin................................. 1,382 396.7 5,229 7.6
Fraser's dolphin................................ 397 114.0 1,665 6.8
Risso's dolphin................................. 1,040 306.7 3,764 8.1
Melon-headed whale.............................. 2,325 685.9 7,003 9.8
Pygmy killer whale.............................. 547 161.4 2,126 7.6
False killer whale.............................. 870 256.8 3,204 8.0
Killer whale.................................... 7 n/a 267 2.6
Short-finned pilot whale........................ 673 198.4 1,981 10.0
----------------------------------------------------------------------------------------------------------------
\1\ Scalar ratios were applied to ``Authorized Take'' values as described at 86 FR 5322, 5404 (January 19, 2021)
to derive scaled take numbers shown here.
\2\ Best abundance estimate. For most taxa, the best abundance estimate for purposes of comparison with take
estimates is considered here to be the model-predicted abundance (Roberts et al., 2016). For those taxa where
a density surface model predicting abundance by month was produced, the maximum mean seasonal abundance was
used. For those taxa where abundance is not predicted by month, only mean annual abundance is available. For
Rice's whale and killer whale, the larger estimated SAR abundance estimate is used.
\3\ Includes 33 takes by Level A harassment and 593 takes by Level B harassment. Scalar ratio is applied to
takes by Level B harassment only; small numbers determination made on basis of scaled Level B harassment take
plus authorized Level A harassment take.
Based on the analysis contained herein of Shell's proposed survey
activity described in its LOA application and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals will be
taken relative to the affected species or stock sizes and therefore is
of no more than small numbers.
Authorization
NMFS has determined that the level of taking for this LOA request
is consistent with the findings made for the total taking allowable
under the incidental take regulations and that the amount of take
authorized under the LOA is of no more than small numbers. Accordingly,
we have issued an LOA to Shell authorizing the take of marine mammals
incidental to its geophysical survey activity, as described above.
Dated: September 6, 2022.
Catherine G. Marzin,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2022-19597 Filed 9-9-22; 8:45 am]
BILLING CODE 3510-22-P