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)

<NOTICE> DEPARTMENT OF COMMERCE <SUBAGY>National Oceanic and Atmospheric Administration</SUBAGY> <DEPDOC>[RTID 0648-XF231]</DEPDOC> <SUBJECT>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)</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. <HD SOURCE="HED">ACTION:</HD> Notice of issuance of letter of authorization. <SUM> <HD SOURCE="HED">SUMMARY:</HD> 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), 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 NMFS has modified the Letter of Authorization (LOA) issued to Chevron for the taking of marine mammals incidental to geophysical survey activity in the GOA. </SUM> <DATES> <HD SOURCE="HED">DATES:</HD> This LOA is effective October 15, 2025, through April 19, 2026. </DATES> <HD SOURCE="HED">ADDRESSES:</HD> The LOA, LOA request, and supporting documentation are available online at: <E T="03">https://www.fisheries.noaa.gov/marine-mammal-protection/issued-letters-authorization-oil-and-gas-industry-geophysical-survey.</E> In case of problems accessing these documents, please call the contact listed below ( <E T="02">FOR FURTHER INFORMATION CONTACT</E> ). <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Carter Esch, Office of Protected Resources, NMFS, (301) 427-8401. </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 <E T="03">et seq.</E> ) 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  <FTREF/> <SU>1</SU> 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. <FTNT> <SU>1</SU>  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). </FTNT> The regulations at 50 CFR 217.180 <E T="03">et seq.</E> 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 (LPAI) standard of the MMPA. NMFS issued a LOA to Chevron on August 27, 2025, for the take of marine mammals incidental to a three-dimensional (3D) ocean-bottom node survey in Lease Block Walker Ridge 678 area, effective December 1, 2025, through April 19, 2026. Please see the <E T="04">Federal Register</E> notice of issuance (90 FR 42749, September 4, 2025) for additional detail regarding the LOA and the survey activity. On September 12, 2025, Chevron informed NMFS that its planned survey timing had shifted due to changing survey schedules and vessel availability. Accordingly, they requested a modification to the LOA to reflect the new survey dates. Chevron has requested that the modified LOA effective period begin October 15, 2025, rather than December 1, 2025. There are no other changes to the survey area or plan, which includes a total of 60 days of sound source operation in Zone 7. Since the survey timing now involves months for which take was not previously assessed, we have updated Chevron's take estimates based on the revised schedule. The monthly distribution of survey days is not known in advance, though we assume that the planned 60 days of source operation would occur contiguously. Take estimates for each species are based on the period that produces the greatest value. Based on the results of our analysis, NMFS has determined that the level of taking expected for this survey and authorized through the modified 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). <HD SOURCE="HD1">Small Numbers Determination</HD> 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 and in the <E T="04">Federal Register</E> notice of issuance for the original LOA (90 FR 42749, September 4, 2025). 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 the ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 14k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━