Stock Assessment Reports

Section 117 of the Marine Mammal Protection Act, as amended in 1994, requires the U.S. Fish and Wildlife Service to report periodically on the status of marine mammal stocks within Alaskan waters. Each stock assessment includes a description of the stock's geographic range, a minimum population estimate, current population trends, current and maximum net productivity rates, optimum sustainable population optimum sustainable population
With respect to any marine mammal population stock, the number of animals which will result in the maximum productivity of the population or the species, keeping in mind the carrying capacity of the habitat and the health of the ecosystem of which they form a constituent element. [defined under MMPA Section 3(9)]

Learn more about optimum sustainable population
levels and allowable removal levels, and estimates of annual human-caused mortality and serious injury through interactions with commercial fisheries and subsistence hunters. Stock assessment reports are used to evaluate the progress of fisheries towards achieving the goal of zero mortality and serious injury to marine mammals.

The following Alaska marine mammal stock assessment reports can be found in the Library Collection linked at the bottom of this page: 

  • Southern Beaufort Sea Polar Bear Stock Assessment (2021)
  • Chukchi/Bering Seas Polar Bear Stock Assessment (2021)
  • Pacific Walrus Stock Assessment (2023) 
  • Southwest Alaska Northern Sea Otter Stock Assessment (2023)
  • Southeast Alaska Northern Sea Otter Stock Assessment (2023)
  • Southcentral Alaska Northern Sea Otter Stock Assessment (2023)

For information on dolphins, porpoises, whales, seals, and sea lions, contact the National Marine Fisheries Service's Office of Protected Resources.


Manatee mother and calf in crystal clear water, split shot inside and outside of the water
One of the goals of the Marine Mammal Protection Act (MMPA) is to ensure that stocks of marine mammals occurring in waters under the jurisdiction of the United States do not have a level of human-caused mortality and serious injury that is likely to cause the stock to be reduced below its optimum...