Pollock Conservation Cooperative Research Center
2000 Awarded Research Projects
The quality of commercial fish species in Steller sea lion habitat units
Robert Foy, Kate Wynne
Award: $56,555
Estimated Completion: December 31, 2001
Abstract
The western stock of Steller sea lions (SSLs) has decreased by about 81% over the past 30 years and is now listed as "endangered" under the Endangered Species Act. Evidence suggests links between low juvenile survival and nutrient limitations (i.e. diets of low quantity, quality, and diversity). Diets of SSLs are diverse and include species important to commercial fisheries in Alaska. Thus, fishing activity in haulout areas is assumed to affect the ability of SSLs to secure food. Based primarily on assumptions about SSL foraging behavior and prey/habitat use, the National Marine Fisheries Service recently imposed restrictions on trawl fishing in 10 nmi radii around SSLs haulouts. The potential for competition between fisheries and marine mammals exists if increased seasonal or age-specific energetic demands of marine mammals coincide with temporal and spatial scarcity of prey resulting from commercial fisheries. We are proposing to determine the seasonal quality of fish species around key SSL habitat so accurate models can be derived to understand the level of interaction with commercial resources. These data will be of practical importance to fisheries managers by providing basic knowledge of the relative quality of fish available as prey for SSLs. This information will also be applicable towards future studies concerned with the transfer of energy within the fish community to better understand the growth and survival of commercially important fishes. Ultimately, this data will be important for commercial fishermen who are now affected by regulations based on inadequate information about SSL–prey interactions. SSL habitat around Kodiak Island will be a representative study site due to its central location to the SSLs decline and the great impact no-trawl zones around SSL haulouts have on the local fishing industry. Results garnered from the studies around Kodiak Island will also be applicable to other important SSL habitat in the western region.
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