Solid management, natural resilience both key to socke...( The resilience of sockeye salmon runs i...)

It's not just an abundance of fish, although the numbers returning to spawn is tens of millions more than the total across the lower 48 states and prudent actions by fishermen and the Alaska Department of Fish and Game have helped make it a classic example of a sustainable fishery.

As it turns out, it's also about having a large number of population segments, or components, the fish in each programmed to breed and thrive under conditions somewhat different from the fish in other components, University of Washington researchers report in this week's Proceedings of the National Academy of Sciences.

It's an important natural buffer in the face of changing environmental conditions, particularly those affected by climate, that can make winners out of seemingly insignificant components of the population, or stock, while dwarfing the once mighty.

Salmon managers in the Pacific Northwest and elsewhere, as well as those overseeing other fish and shellfish populations, need to consider this biocomplexity within a species, say the UWs Ray Hilborn, Thomas P. Quinn and Donald Rogers, all professors of aquatic and fishery sciences, and Daniel Schindler, associate professor of biology. The loss of biocomplexity is a characteristic of salmon in the Pacific Northwest, where many stock components were lost because of dams or deliberate overharvesting in an attempt to maximize catch from hatcheries, the authors say.

Its why protecting only the habitat and fish of todays strongest runs is a mistake. One cant know for sure which runs might stumble in the future, Quinn says.

Sockeye is one of four species of salmon found on the West Coast and in Alaska. It is most different from the other species because the young spend a year, sometimes more, in freshwater lakes before head
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Contact: Sandra Hines
shines@u.washington.edu
206-543-2580
University of Washington
9-May-2003