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Steller Sea Lions in Alaska: Complexity of the Problem

photo of Steller sea lions

Photo: Jason Waite, Alaska SeaLife Center

(PLEASE NOTE: These web pages are for archival purposes only and are no longer maintained. For current information on Steller sea lion research at the AFSC visit the National Marine Mammal Lab's Alaska Ecosystems Program.)

The listing of the Steller sea lion (Eumetopias jubatus) as a threatened species under the Endangered Species Act in 1990 created new challenges for fisheries managers in the National Marine Fisheries Service and the North Pacific Fisheries Management Council. Managers must balance between two sometimes conflicting objectives: protecting and aiding the recovery of the Steller sea lion under the Endangered Species Act while at the same time providing for sustainable and economically viable fisheries under the Magnuson-Stevens Fishery Conservation and Management Act. Groundfish fisheries in the Gulf of Alaska, Bering Sea, and Aleutian Islands, some of the largest and most valuable in the world, operate in a large portion of the Steller sea lionís distribution and target some of the same species that form a large part of the sea lionís diet.

Graph showing the decline of the western stock of Steller sea lions from approx. 170,000 animals in 1970 to 30,000 in 2000.

However, there are many other factors besides fisheries that could be affecting survival and birth rates of Steller sea lions. During the period that Steller sea lions have been declining, there have been large changes in the climate of the North Pacific ocean that may have altered the distribution and recruitment of fish stocks upon which sea lions feed. Pollutants and diseases could also be interfering with sea lion growth or reproduction. Killer whales and other predators could be feeding more on sea lions than in the past. And there is always the possibility that other human interactions, such as undocumented illegal shooting, could be higher than we think.

Protection Measures

> Rookeries are protected by fishery closures and no-transit zones.

> No pollock fishing is allowed within 10-20 nautical miles of 75 haulouts.

> Fishing is controlled in part of sea lion critical habitat.

> Critical habitat in the Aleutian Islands is closed to pollock fishing.
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For these reasons, NMFS is engaged in management activities to insure that our current groundfish fisheries are not adversely affecting Steller sea lions or impeding their recovery, and research activities to understand why the population continues to decline. The North Pacific ecosystem in which Steller sea lions are a part is complex, large, and at times, inhospitable. Many of the issues raised in addressing management and research questions also appear to be intractable. Despite these obstacles, NMFS and our management and research partners are vigorously pursuing answers to these questions so that groundfish fisheries and Steller sea lions can coexist in the North Pacific ocean. As part of this effort, the Alaska Fisheries Science Center is administering the Steller Sea Lion Coordinated Research Program, which consists of more than 150 research projects conducted on Steller sea lions at institutions throughout the world.