Notice2025-22198
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil and Gas Activities in the Gulf of America (Formerly Gulf of Mexico)
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 8, 2025
Effective
December 3, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
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 America, originally published as "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 WesternGeco LLC (WesternGeco) for the take of marine mammals incidental to geophysical survey activity in the Gulf of America (GOA).
Full Text
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<title>Federal Register, Volume 90 Issue 233 (Monday, December 8, 2025)</title>
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[Federal Register Volume 90, Number 233 (Monday, December 8, 2025)]
[Notices]
[Pages 56734-56737]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-22198]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XF349]
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to Geophysical Surveys Related to Oil and Gas Activities in
the Gulf of America (Formerly Gulf of Mexico)
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; 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 America, originally published as
``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
WesternGeco LLC (WesternGeco) for the take of marine mammals incidental
to geophysical survey activity in the Gulf of America (GOA).
DATES: The LOA is effective December 3, 2025 through April 19, 2026.
ADDRESSES: The LOA, LOA request, and supporting documentation are
available online at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-oil-and-gas-industry-geophysical-survey-activity-gulf-america">https://www.fisheries.noaa.gov/action/incidental-take-authorization-oil-and-gas-industry-geophysical-survey-activity-gulf-america</a>. In case of problems accessing these documents, please
call the contact listed below (see FOR FURTHER INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Jenna Harlacher, 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,
[[Page 56735]]
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 GOA
\1\ 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, and became effective on April 19, 2021.
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\1\ Pursuant to Executive Order 14172, ``Restoring Names That
Honor American Greatness,'' and Department of the Interior
Secretarial Order 3423, ``The Gulf of America,'' the body of water
formerly known as the Gulf of Mexico is now called the Gulf of
America. Accordingly, NMFS amended the incidental take regulations
to reflect the change. See 90 FR 38001 (August 7, 2025).
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The 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.
NMFS subsequently discovered that the 2021 rule was based on
erroneous take estimates. We conducted another rulemaking using correct
take estimates and other newly available and pertinent information
relevant to the analyses supporting some of the findings in the 2021
final rule and the taking allowable under the regulations. We issued a
final rule in April 2024, effective May 24, 2024 (89 FR 31488, April
24, 2024).
The 2024 final rule made no changes to the specified activities or
the specified geographical region in which those activities would be
conducted, nor to the original 5-year period of effectiveness. In
consideration of the new information, the 2024 rule presented new
analyses supporting affirmance of the negligible impact determinations
for all species, and affirmed that the existing regulations, which
contain mitigation, monitoring, and reporting requirements, are
consistent with the ``least practicable adverse impact'' standard of
the MMPA.
Summary of Request and Analysis
WesternGeco plans to conduct a three-dimensional (3D) ocean bottom
node (OBN) survey over 200 lease blocks in the Green Canyon and Walker
Ridge areas, with water depths ranging from approximately 1,400 to
3,200 meters (m). See section F of the LOA application for a map of the
area.
WesternGeco would use one of the following source configurations: a
conventional airgun array source consisting of 28 elements with a total
volume of 5,000 cubic inches (in\3\) or a combination of the
conventional airgun array source and a low-frequency tuned pulse source
(TPS). Please see WesternGeco's application for additional detail.
The TPS was not included in the acoustic exposure modeling
developed in support of the rule. However, the TPS was previously
described and evaluated in support of previous LOAs, and we rely on
those analyses here (86 FR 37309, 37310, July 15, 2021; see also 87 FR
55790, 55791, September 12, 2022). For additional detail regarding
sources, see section C of the LOA application. Based on this
information we have determined there will be no effects of a magnitude
or intensity different from those evaluated in support of the rule.
NMFS therefore expects that use of modeling results supporting the
final rule relating to use of airgun arrays are expected to be
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 WesternGeco in its LOA request was used to develop LOA-
specific take estimates based on the acoustic exposure modeling results
described in the preamble (89 FR 31488, April 24, 2024). Because
WesternGeco plans to use the specified 28-element, 5,000 in\3\ airgun
array source for either source configuration, this source was used to
evaluate the appropriate proxy array. In order to generate the
appropriate take numbers for authorization, the following information
was considered: (1) survey type; (2) location (by modeling zone); \2\
(3) number of days; (4) source; and (5) month.\3\ To determine the most
appropriate proxy array from the exposure modeling, the directionally
dependent source level in a plane parallel to the sea surface was
compared to the three airgun array sources which were originally
modeled, including the 4,130, 5,110, and 8,000 in\3\ arrays. Out of
these three proxies, the source which had the smallest relative error
(arithmetic mean difference taken over the azimuthal or vessel bearing
angle) was chosen as the most representative proxy. In this case, the
5110 in\3\ had the lowest mean error (0.9 decibel) and was the airgun
array proxy that was selected. The acoustic exposure modeling performed
in support of the rule provides 24-hour exposure estimates for each
species, specific to each modeled source and survey type in each zone
and month.
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\2\ For purposes of acoustic exposure modeling, the GOA was
divided into seven zones. Zone 1 is not included in the geographic
scope of the rule.
\3\ Acoustic propagation modeling was performed for two seasons:
Winter (December-March) and Summer (April-November). Marine mammal
density data is generally available on a monthly basis, and
therefore further refines take estimates temporally.
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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 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. 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 WesternGeco is not proposing to perform a survey
using the coil geometry, the coil proxy is most representative of the
effort planned by WesternGeco in terms of predicted Level B harassment
exposures.
The survey will take place over approximately 100 days with 80 days
of sound source operation, with 30 days planned in Zone 5 and 50 days
planned in Zone 7. The monthly distribution of survey days is not known
in advance, though we assume that the planned 80 days of source
operation would occur contiguously. Take estimates for each
[[Page 56736]]
species are based on the time period that produces the greatest value.
For the Rice's whale, take estimates based on the modeling yielded
results that are not realistically likely to occur when considered in
light of other relevant information concerning Rice's whale habitat
preferences considered during the rulemaking process. NMFS' 2024 final
rule provided detailed discussion regarding Rice's whale habitat (see,
e.g., 89 FR 31508, 31519, April 24, 2024). In summary, recent survey
data, sightings, and acoustic data support Rice's whale occurrence in
waters throughout the GOA between approximately 100 m and 400 m depth
along the continental shelf break, and associated habitat-based density
modeling has identified similar habitat (i.e., approximately 100 to 400
m water depths along the continental shelf break) as being Rice's whale
habitat (Garrison et al., 2023; Soldevilla et al., 2022, 2024).
Although Rice's whales may occur outside of the general depth range
expected to provide suitable habitat, we expect that any such
occurrence would be rare. WesternGeco's planned activities will occur
in water depths of approximately 1,400 to 3,200 m in the central GOA.
Thus, NMFS does not expect there to be the reasonable potential for
take of Rice's whale in association with this survey and, accordingly,
does not authorize take of Rice's whale through the LOA.
Based on the results of our analysis, NMFS has determined that the
level of taking expected for this survey and authorized through the LOA
is consistent with the findings made for the total taking allowable
under the regulations. See table 1 in this notice and table 6 of the
rule (89 FR 31488, April 24, 2024).
Small Numbers Determination
Under the 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 (see 89 FR 31535, May 24, 2024). For
more information please see NMFS' discussion of small numbers in the
2021 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 (except in the cases where the take estimate has been rounded up
to reflect a group size) 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 1 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 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; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and model-predicted
abundance information (<a href="https://seamap.env.duke.edu/models/Duke/GOM/">https://seamap.env.duke.edu/models/Duke/GOM/</a>).
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.................................... 0 n/a 51 n/a
Sperm whale..................................... 295 125 2,451 5.1
Kogia spp....................................... \3\ 313 94.1 1,385 8.2
Beaked whales................................... 1,033 104 1,038 10.1
Rough-toothed dolphin........................... 1,382 397 4,853 8.2
Bottlenose dolphin.............................. 703 202 166,538 0.1
Clymene dolphin................................. 1,875 538 6,136 8.8
Atlantic spotted dolphin........................ 202 58 21,506 0.3
Pantropical spotted dolphin..................... 14,871 4268 50,209 8.5
Spinner dolphin................................. 166 48 2,991 1.6
Striped dolphin................................. 5,341 1,533 16,102 9.5
Fraser's dolphin................................ 572 164.2 1,665 9.9
Risso's dolphin................................. 164 48 1,974 2.4
Blackfish \4\................................... 4,081 1,204 9,535 12.6
Short-finned pilot whale........................ 148 44 3,277 1.3
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\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 (Garrison et al., 2023). For Rice's whale,
Atlantic spotted dolphin, and Risso's dolphin, the larger estimated SAR abundance estimate is used.
\3\ Includes 20 takes by Level A harassment and 293 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.
\4\ The ``blackfish'' guild includes melon-headed whales, false killer whales, pygmy killer whales, and killer
whales.
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 (i.e.,
less than one-third of the best available abundance estimate) and
therefore the taking is of no more than small numbers.
[[Page 56737]]
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: December 4, 2025.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2025-22198 Filed 12-5-25; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on December 8, 2025.
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