[Federal Register Volume 88, Number 190 (Tuesday, October 3, 2023)]
[Notices]
[Pages 68106-68109]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-21760]
[[Page 68106]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD400]
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.
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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 TGS for the
take of marine mammals incidental to geophysical survey activity in the
Gulf of Mexico.
DATES: The LOA is effective from September 29, 2023 through September
28, 2024.
ADDRESSES: The LOA, LOA request, and supporting documentation are
available online at: https://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: Rachel Wachtendonk, 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) 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 U.S. waters of the
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
TGS plans to conduct a three-dimensional (3D) ocean bottom node
(OBN) survey in the Green Canyon, Ewing Bank, and Atwater Valley
protraction areas, including approximately 380 lease blocks.
Approximate water depths of the survey area range from 150 to 2,000
meters (m). See section F of the LOA application for a map of the area.
TGS anticipates using two source vessels, each towing low-frequency
airgun sources known as Gemini (also referred to as a dual barbell
source). Please see TGS's application for additional detail. The Gemini
source was not included in the acoustic exposure modeling developed in
support of the rule. However, our 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 was previously evaluated as a NUT in 2020 (prior to
issuance of the 2021 final rule) pursuant to the requirements of NMFS'
2020 Biological Opinion on BOEM's Gulf of Mexico oil and gas program as
well as the issuance of the rule. An associated report produced by
Jasco Applied Sciences (Grooms et al., 2019) provides information
related to the acoustic output of the Gemini source, which informs our
evaluation here.
The Gemini source 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.
However, the Gemini source consists of one physical element with two
large chambers of 4,000 cubic inches (in\3\) each (total volume of
8,000 in\3\). This creates a larger bubble resulting in more of the
energy being concentrated in low frequencies, with a fundamental
frequency of 3.7 Hertz. In addition to concentrating energy at lower
frequencies, the Gemini source is expected to produce lower overall
sound levels than the conventional airgun proxy source. The number of
airguns in an array is highly influential on overall sound energy
output, because the output increases approximately linearly with the
number of airgun elements. In this case, because the same air volume is
used to operate two very large guns, rather than tens of smaller guns,
the array produces lower sound
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levels than a conventional array of equivalent total volume.
The modeled distances described in the aforementioned Jasco report
show expected per-pulse sound pressure level threshold distances to the
160-dB level of 4.29 kilometers (km). When frequency-weighted, i.e.,
considering the low frequency output of the source relative to the
hearing sensitivities of different marine mammal hearing groups, the
estimated distance is decreased to approximately 1 km for the low-
frequency cetacean hearing group and to de minimis levels for mid- and
high-frequency cetacean hearing groups, significantly less than
comparable modeled distances for the proxy 72-element, 8,000 in\3\
array evaluated in the rule.
These factors lead to a conclusion that take by Level B harassment
associated with use of the Gemini source would be less than would occur
for a similar survey instead using the modeled airgun array as a sound
source. 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 Gemini source.
Consistent with the preamble to the final rule, the survey effort
proposed by TGS 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.
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\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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No 3D OBN surveys were included in the modeled survey types, and
use of existing proxies (i.e., two-dimensional (2D), 3D narrow-azimuth
(NAZ), 3D wide-azimuth (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 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 approximately 56 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 TGS is not proposing to perform a survey
using the coil geometry, its planned 3D OBN survey is expected to cover
approximately 55 km\2\ per day, meaning that the coil proxy is most
representative of the effort planned by TGS 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,
as discussed above, estimated take numbers for this LOA are considered
conservative due to differences between the Gemini acoustic source
planned for use and the proxy array modeled for the rule.
The survey will take place over approximately 114 days, including
65 days of sound source operation. The survey plan includes
approximately 64 days within Zone 5 and approximately 1 day within Zone
2. 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.
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 (e.g., 86 FR 5322, 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 Rice's
whales and killer whales produces results 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.
NMFS' final rule described a ``core habitat area'' for Rice's
whales (formerly known as GOM Bryde's whales) \3\ located in the
northeastern GOM in waters between 100 and 400 m depth along the
continental shelf break (Rosel et al., 2016). 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, June 22,
2018; 83 FR 29280, June 22, 2018; 86 FR 5418, January 19, 2021.
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\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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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 available records, these occurrences would be rare. TGS'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))
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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, January 19, 2021; 86
FR 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
(as discussed above) 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 to 2009
reported only 16 sightings of killer whales, with an additional 3
encounters during more recent survey effort from 2017 to 2018 (Waring
et al., 2013; https://www.boem.gov/gommapps). Two other species were
also observed on fewer than 20 occasions during the 1992-2009 NOAA
surveys (Fraser's dolphin and false killer whale \4\). However,
observational data collected by protected species observers (PSOs) on
industry geophysical survey vessels from 2002 to 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.\4\ However, note that these species have been
observed over a greater range of water depths in the GOM than have
killer whales. (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 5322 and 86 FR 5334 (January
19, 2021), and similarly informs our analysis here.
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\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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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 and 10 m. Similarly, Kvadsheim et al. (2012)
reported data from a study of 4 killer whales, noting that the whales
performed 20 times as many dives 1-30 m in 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. This
survey would take place in deep waters that would overlap with depths
in which killer whales typically occur. 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
will generally result in estimated take numbers that are inconsistent
with the assumptions made in the rule regarding expected killer whale
take (86 FR 5322, January 19, 2021; 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 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; 86 FR 29090, May 28,
2021; 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
two animals for Rice's whale and up to seven animals for killer
whales).
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, which are determined as
described above, are used by NMFS in making the necessary small numbers
determinations through comparison with the best available abundance
estimates (see discussion at 86 FR 5322, January 19, 2021; 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; https://www.fisheries.noaa.gov/national/
marine-mammal-protection/marine-
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mammal-stock-assessment-reports-species-stock) 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
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Authorized Scaled take Percent
Species take \1\ Abundance \2\ abundance
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Rice's whale.................................... 2 n/a 51 3.9
Sperm whale..................................... 1,683 705.6 2,207 32.0
Kogia spp....................................... \3\ 636 193.4 4,373 5.2
Beaked whales................................... 7,430 750.4 3,768 19.9
Rough-toothed dolphin........................... 1,293 2,197.3 4,853 1.2
Bottlenose dolphin.............................. 7,656 562.7 176,108 0.3
Clymene dolphin................................. 3,595 1,031.7 11,895 8.7
Atlantic spotted dolphin........................ 2,664 764.6 74,785 1.0
Pantropical spotted dolphin..................... 16,313 4,681.8 102,361 4.6
Spinner dolphin................................. 4,371 1,254.5 25,114 5.0
Striped dolphin................................. 1,404 403.0 5,229 7.7
Fraser's dolphin................................ 404 116.0 1,665 7.0
Risso's dolphin................................. 1,056 311.6 3,764 8.3
Melon-headed whale.............................. 2,362 696.7 7,003 9.9
Pygmy killer whale.............................. 556 164.0 2,126 7.7
False killer whale.............................. 885 261.2 3,204 8.2
Killer whale.................................... 7 n/a 267 2.6
Short-finned pilot whale........................ 683 201.5 1,981 10.2
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\1\ Scalar ratios were applied to ``Authorized Take'' values as described at 86 FR 5322 and 86 FR 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 the killer whale, the larger estimated SAR abundance estimate is used.
\3\ Includes 34 takes by Level A harassment and 602 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 TGS'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 (i.e., less than
one-third of the best available abundance estimate) and therefore the
taking 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 TGS authorizing the take of marine mammals
incidental to its geophysical survey activity, as described above.
Dated: September 27, 2023.
Catherine Marzin,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2023-21760 Filed 10-2-23; 8:45 am]
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