Notice2026-18760
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil and Gas Activities in the Gulf of America
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
September 14, 2026
Effective
September 9, 2026
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 (GOA), notification is hereby given that NMFS has issued a Letter of Authorization (LOA) to TGS for the take of marine mammals incidental to geophysical survey activity in the GOA.
Full Text
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<title>Federal Register, Volume 91 Issue 176 (Monday, September 14, 2026)</title>
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[Federal Register Volume 91, Number 176 (Monday, September 14, 2026)]
[Notices]
[Pages 58098-58100]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-18760]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XG043]
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to Geophysical Surveys Related to Oil and Gas Activities in
the Gulf of America
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 (GOA), notification is hereby
given that NMFS has issued a Letter of Authorization (LOA) to TGS for
the take of marine mammals incidental to geophysical survey activity in
the GOA.
DATES: The LOA is effective September 9, 2026, through September 1,
2027.
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.
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, 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
[[Page 58099]]
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).
On August 28, 2025, NMFS Office of Protected Resources received a
request from NMFS Office of Policy for reimplementation of the current
incidental take regulation (ITR) to avoid a lapse in ITRs offering
incidental take coverage for GOA geophysical survey activities. On
October 20, 2025, Bureau of Ocean Energy Management (the original
petitioner for the current ITRs) submitted a request to be included in
the process as a co-petitioner. In response to these requests, NMFS
issued a new final rule, effective April 20, 2026, through April 19,
2031 (91 FR 20784, April 17, 2026).
The reimplementation of the regulations continues the established
framework for authorization of incidental take through LOAs. The final
rule made no changes to the specified activities or the specified
geographical region in which those activities would be conducted, and
there are no changes to the associated mitigation, monitoring, and
reporting requirements.
Summary of Request and Analysis
TGS plans to conduct a three-dimensional (3D) ocean-bottom node
(OBN) survey over approximately 600 lease blocks in the East Breaks and
Alaminos Canyon areas, with water depths ranging from approximately 900
to 3,200 meters (m).
TGS plans to use a low-frequency airgun source known as Gemini
(also referred to as a dual barbell source). Gemini airgun arrays will
fire using the ``Seismic Apparition'' method, with a single-source
vessel towing six sources (100-m separation), firing within 120
milliseconds with a predetermined dither to each source; no sources
will fire simultaneously at any time.
Gemini was not included in the acoustic exposure modeling developed
in support of the rule. However, Gemini was described and evaluated in
support of a previous LOA, and we rely on that analysis here (88 FR
72739, October 23, 2023). For additional details regarding sources, see
section C of the LOA application. Based on this information we have
determined there will be no effects of 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 is expected to be conservative as a proxy for use in
evaluating potential impacts of use of Gemini.
Consistent with the preamble to the 2026 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 (91 FR 20784, April 17, 2026). In order to
generate the appropriate take number for authorization, the following
information was considered: (1) survey type; (2) location (by modeling
zone \i\); (3) number of days; (4) source; and (5) month.\ii\ 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. For
a single 8,000-in\3\ Gemini source, surface affected waveforms were
modeled by TGS using Nucleus+. To approximate the acoustic energy from
six elements, the SEL for each frequency and aspect was adjusted by a
factor of 10*log<INF>10</INF> (N), where N in this case is 6. The
resulting spectra were used in the comparison tool. The results showed
that the most comparable source was the 4,130-in\3\ array. The Nucleus+
results indicate that the horizontal surface-affected SEL source level
for a single 8,000-in\3\ array is approximately 218.2 dB, while the
additional 10*log<INF>10</INF> (6) increases this to approximately 226
dB. Notably, the corresponding source level for the 4,130-in\3\ source
is approximately 232 dB. Thus, the total acoustic energy from six
8,000-in\3\ Gemini sources remains lower than the conventional 4,130-
in\3\ array. 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.
No 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 (91 FR 9014, 9018, February 24, 2026).
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 TGS is not proposing to perform a survey
using the coil geometry, the coil proxy is most representative of the
effort planned by TGS in terms of predicted Level B harassment
exposures.
NMFS previously issued a LOA to TGS on June 26, 2026, for the take
of marine mammals incidental to a 3D OBN survey in the East Breaks and
Alaminos Canyon areas, effective September 1, 2026, through September
1, 2027. Please see the Federal Register notice of issuance (91 FR
39072, June 29, 2026) for additional details regarding the LOA and the
proposed survey activity.
On August 25, 2026, TGS informed NMFS that its planned survey area
had shifted and, accordingly, they requested a new LOA based on the
updated survey area. This new LOA will replace the LOA previously
issued to TGS.
The updated survey plan includes 102 total days of sound source
operation with 74 days in zone 6 and 28 days in zone 7. The monthly
distribution of survey days is not known in advance, though we assume
that the planned 102 days of source operation would occur contiguously.
Take estimates for each species are based on the time period that
produces the greatest value and have been updated based on the revised
survey plan.
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 7 of the
rule (91 FR 20784, April 17, 2026).
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
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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 (91 FR 20784, April 17, 2026). For more
information, please see NMFS' discussion of small numbers in the 2026
final rule (91 FR 20784, April 17, 2026).
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 (91 FR 20784, April 17, 2026). 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 91 FR 20784, 20812, April 17, 2026). 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/SEFSC/GOM/">https://seamap.env.duke.edu/models/SEFSC/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..................................... 707 299 2,451 12.2
Kogia spp....................................... \3\ 335 101 1,385 8.8
Beaked whales................................... 298 30 1,038 2.9
Rough-toothed dolphin........................... 1,887 542 4,853 11.2
Bottlenose dolphin.............................. 2,141 614 166,538 0.4
Clymene dolphin................................. 3,487 1,001 6,136 16.3
Atlantic spotted dolphin........................ 3,587 1,029 21,506 4.8
Pantropical spotted dolphin..................... 16,405 4,708 50,209 9.4
Spinner dolphin \4\............................. 152 n/a 2,991 5.1
Striped dolphin................................. 3,944 1,132 16,102 7.0
Fraser's dolphin................................ 776 223 1,665 13.4
Risso's dolphin................................. 460 136 1,974 6.9
Blackfish \5\................................... 5,562 1,641 9,535 17.2
Short-finned pilot whale........................ 2,158 637 3,277 19.4
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\1\ Scalar ratios were applied to ``Authorized Take'' values as described at 91 FR 20784, 20818 (April 17, 2026)
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, spinner dolphin, and Risso's dolphin, the estimated SAR abundance estimate is used.
\3\ Includes 20 takes by Level A harassment and 315 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\ Modeled take of 81 increased to account for potential encounter with a group of average size (Maze-Foley and
Mullin, 2006).
\5\ The ``blackfish'' guild includes melon-headed whales, false killer whales, pygmy killer whales, and killer
whales.
Based on the analysis contained herein of TGS's proposed survey
activity described in its LOA request 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 a LOA to TGS, authorizing the take of marine mammals
incidental to its geophysical survey activity, as described above.
Dated: September 9, 2026.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2026-18760 Filed 9-11-26; 8:45 am]
BILLING CODE 3510-22-P
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