Welcome to the U.S. Navy's website for the Gulf of Alaska Navy Training Activities Supplemental Environmental Impact Statement/Overseas Environmental Impact Statement (EIS/OEIS).

The Navy is preparing a supplement to the 2011 Gulf of Alaska Navy Training Activities Final EIS/OEIS and the 2016 Gulf of Alaska Navy Training Activities Final Supplemental EIS/OEIS to assess the potential environmental effects associated with continuing periodic military readiness activities within the Gulf of Alaska Study Area. Proposed training activities are similar to those that have occurred in the Study Area for decades. The Navy would continue to implement mitigation measures to avoid or reduce potential impacts on marine species and the environment from training activities.
The purpose of the Supplemental EIS/OEIS is to update the 2011 and 2016 impact analyses with new information and analytical methods. New information includes an updated acoustic effects model, updated marine species density data and hearing criteria, and other emergent best available science.
The Navy is preparing the Supplemental EIS/OEIS in support of the renewal of federal regulatory permits and authorizations under the Marine Mammal Protection Act and the Endangered Species Act. Current federal regulatory permits and authorizations expire in April 2022.
March 2022 Update: Notice of Availability of the Supplement to the 2020 Draft Supplemental EIS/OEIS
On Feb. 1, 2022, the Navy announced its intent to prepare a Supplement to the 2020 Draft Supplemental EIS/OEIS. This Supplement addresses a change in the Study Area and the addition of a new Continental Shelf and Slope Mitigation Area. The Supplement was available for review and comment from March 18, 2022, to May 2, 2022.
Since the release of the 2020 Draft Supplemental EIS/OEIS and completion of the Northern Edge 2021 exercise, the Navy recognized that the size and shape of the Gulf of Alaska Temporary Maritime Activities Area (approximately 42,146 square nautical miles) no longer provides sufficient space for the realistic maneuvering of vessels and aircraft during training exercises. Proposed changes to the Study Area include additional airspace and sea space to the west and south of the Temporary Maritime Activities Area. This additional space would enable Navy personnel and units to practice more realistic, complex training scenarios in a safer, more efficient manner that would better prepare them to respond to real-world incidents. The additional area is referred to as the Western Maneuver Area and adds approximately 185,806 square nautical miles to the Study Area.
The Navy is not proposing new or increased number of training activities in the Western Maneuver Area, only an expansion of the area the Navy may use for vessel and aircraft maneuvering purposes during exercises. The number of vessels, aircraft, underway steaming hours, events, and flight times remains the same. The use of sonar or explosives would not occur in the Western Maneuver Area.
In direct response to agency, tribal, and public comments, the Navy also proposes implementing a new mitigation area within the continental shelf and slope area of the Temporary Maritime Activities Area. The Navy would expand its mitigation measures for explosives detonated at or near the surface and prohibit the use of explosives during training (up to 10,000 feet altitude) in this area to protect marine species and biologically important habitat. The Navy anticipates the implementation of the proposed mitigation area would reduce impacts on marine mammals, fishes, and marine birds.