# 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.
**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 NMFS has modified the Letter of Authorization (LOA) issued to TGS for the take of marine mammals incidental to geophysical survey activity in the Gulf of America (GOA).
**DATES:**
The LOA is effective through December 31, 2025.
**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 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.
[^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, this *Federal Register* Notice hereafter refers to the Gulf of America.
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 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.
NMFS issued a LOA to TGS on March 17, 2025, for the take of marine mammals incidental to a three-dimensional (3D) ocean bottom node (OBN) survey over 240 lease blocks in the Garden Banks, Keathley Canyon, and Sigsbee Escarpment areas, effective March 17, 2025 through December 31, 2025. Please see the *Federal Register* notice of issuance (90 FR 13346, March 21, 2025) for additional detail regarding the LOA and the survey activity.
On March 21, 2025, TGS informed NMFS that its planned survey area had shifted and, accordingly, they have requested a modification to the LOA to reflect the new survey area. No survey activity has begun. The original survey plan included a total of 64 days of sound source operation, with 38 days in Zone 5, 15 days in Zone 6, and 11 days in Zone 7. The updated survey plan decreased to 62 total days of sound source operation, with the distribution shifted to include 43 days in Zone 5, 15 days in Zone 6, and 4 days in Zone 7. The monthly distribution of survey days is not known in advance, though we assume that the planned 62 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. There are no other changes to the planned survey.
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 in the *Federal Register* notice of issuance (90 FR 13346, March 21, 2025). 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 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; *https://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/* ). Information supporting the small numbers determinations is provided in table 1.
| Species | Authorized | Scaled take | Abundance | Percent |
| --- | --- | --- | --- | --- |
| Rice's whale | 0 | n/a | 51 | n/a |
| Sperm whale | 523 | 211.3 | 3,007 | 7.4 |
| spp | 176 | 53.6 | 980 | 6.4 |
| Beaked whales | 1,430 | 144.5 | 803 | 18.0 |
| Rough-toothed dolphin | 1,367 | 392.3 | 4,853 | 8.1 |
| Bottlenose dolphin | 1,705 | 489.3 | 165,125 | 0.3 |
| Clymene dolphin | 1,240 | 356.0 | 4,619 | 7.7 |
| Atlantic spotted dolphin | 1,108 | 317.9 | 21,506 | 1.5 |
| Pantropical spotted dolphin | 11,650 | 3,343.5 | 67,225 | 5.0 |
| Spinner dolphin | 207 | 59.5 | 5,548 | 1.1 |
| Striped dolphin | 2,127 | 610.3 | 5,634 | 10.8 |
| Fraser's dolphin | 518 | 148.7 | 1,665 | 8.9 |
| Risso's dolphin | 416 | 122.8 | 1,974 | 6.2 |
| Blackfish | 3,196 | 942.9 | 6,113 | 15.4 |
| Short-finned pilot whale | 956 | 282.0 | 2,741 | 10.3 |
Based on the analysis contained herein of TGS's proposed survey activity described in its LOA application, as subsequently modified by TGS, 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 modification to the LOA to TGS authorizing the take of marine mammals incidental to its geophysical survey activity, as described above.
Dated: March 31, 2025.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries Service.