# 2026-03375: Oil Firm Allowed to Disturb Alaska Sea Mammals for Five Years 2026-03375, Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Hilcorp Alaska, LLC Oil and Gas Activities in Cook Inlet, Alaska, is a Federal Register rule from Commerce Department, National Oceanic and Atmospheric Administration published 2026-02-20, effective 2026-02-20 (as of 2026-06-11). - Canonical: https://policyrisk.com/federal-register/2026-03375 - As of: 2026-06-11 - Plain-text twin of the page above; the HTML and this file carry the same facts. ## Facts - Document number: 2026-03375 - Title: Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Hilcorp Alaska, LLC Oil and Gas Activities in Cook Inlet, Alaska - Type: Rule - Agencies: Commerce Department; National Oceanic and Atmospheric Administration - Citation: 91 FR 8123 - Published: 2026-02-20 - Effective: 2026-02-20 - Comments close: not stated - Significant: no - Touches household money: no - Regulation identifier numbers: 0648-BN57 - Last updated: 2026-06-11 ## In one line Oil Firm Allowed to Disturb Alaska Sea Mammals for Five Years ## Summary Hilcorp Alaska got the green light to do oil and gas work in Cook Inlet from 2026 to 2031, even if it means accidentally disturbing some marine mammals. The new rules make sure they minimize harm, keep an eye on the animals, and report what they find. This plan balances energy work with protecting Alaska’s sea creatures over the next five years. ## Abstract NMFS, upon request from Hilcorp Alaska, LLC (Hilcorp), issues this final rule pursuant to the Marine Mammal Protection Act (MMPA), to govern the taking of marine mammals incidental to specified activities conducted in support of oil and gas exploration, development, production, and decommissioning in Cook Inlet, Alaska, over the course of 5 years (2026-2031) and an associated letter of authorization (LOA). Together, the final rule and LOA allow for the incidental take of marine mammals during the described specified activities and timeframes, prescribes the permissible methods of taking and other means of effecting the least practicable adverse impact on marine mammal species and their habitat, and establishes requirements pertaining to the monitoring and reporting of such taking. ## Effects PRIA read - Five-year OK for Hilcorp’s Cook Inlet Work: benefit, high. Hilcorp Alaska is authorized to conduct oil and gas activities in Cook Inlet, Alaska, from February 20, 2026 through February 19, 2031 and to incidentally harass marine mammals. The rule allows Level B harassment for 12 marine mammal species (15 stocks) and Level A harassment for a subset of 9 spec… - Seasonal Work Timing Limits to Protect Belugas: cost, medium. Vessels operating for the project must stay 2.4 km (1.5 miles) away from the Susitna Delta mean lower low water line between April 15 and November 15, and pile driving is restricted to November 15 through April 15 to reduce impacts when Cook Inlet beluga whales are more likely to forage. These date… - Observers, Soft Starts, and Shutdown Rules: cost, medium. The rule requires NMFS-approved protected species observers (PSOs) on project vessels, a soft start for impact pile driving, and delay or shutdown of certain activities if a marine mammal is detected inside clearance or shutdown zones. These measures can cause operational pauses and require qualifi… - Monitoring Reports Required After Work: cost, low. Hilcorp must submit monitoring reports that summarize marine mammal species and behavioral observations, construction shutdowns or delays, and construction work completed. These reporting requirements apply during the rule’s effective period (February 20, 2026–February 19, 2031) and require recordk… - Subsistence Availability and No Mortality Allowed: benefit, medium. NMFS determined the authorized incidental take will have a negligible impact on marine mammal populations and will not have an unmitigable adverse impact on the availability of species for subsistence uses. The rule also explicitly states no serious injury or mortality of any marine mammal is autho… ## Related documents - [2026-14204](https://policyrisk.com/federal-register/2026-14204): Lake Ontario National Marine Sanctuary; Delay of Effective Date, 2026-07-15 - [2026-14195](https://policyrisk.com/federal-register/2026-14195): Rescinding the Definition of “Harm” Under the Endangered Species Act, 2026-07-14 - [2026-07536](https://policyrisk.com/federal-register/2026-07536): Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Geophysical Surveys in the Gulf of America, 2026-04-17 - [2026-05599](https://policyrisk.com/federal-register/2026-05599): Deep Seabed Mining: Notice of Receipt of Applications for Deep Seabed Mining Exploration Licenses and Announcement of Public Comment Period…, 2026-03-23 - [2026-04256](https://policyrisk.com/federal-register/2026-04256): Atlantic Highly Migratory Species; Spatial Fisheries Management; Amendment 15 to the 2006 Consolidated Atlantic Highly Migratory Species Fi…, 2026-03-04 - [2025-06746](https://policyrisk.com/federal-register/2025-06746): Rescinding the Definition of “Harm” Under the Endangered Species Act, 2025-04-17 ## Sources - [2026-03375 on federalregister.gov](https://www.federalregister.gov/documents/2026/02/20/2026-03375/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to) - [2026-03375 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-02-20/pdf/2026-03375.pdf) ## Related - [Previous: 2026-03371, Pesticide Tolerances; Implementing Registration Review Decisions for Certain Pe…](https://policyrisk.com/federal-register/2026-03371) - [Next: 2026-03384, Streamlining the Regulations Governing Requests for Special Census Services and…](https://policyrisk.com/federal-register/2026-03384) - [All Federal Register documents](https://policyrisk.com/federal-register) Source: PRIA, https://policyrisk.com/federal-register/2026-03375 (as of 2026-06-11).