Effectively addressing ecosystem understanding: solutions to the limitations of current fisheries and oceans policy

摘要

There is increasing awareness of the need for "ecosystem-based" management, but insufficient recognition that the underlying limitations of current fisheries and ocean policy are centered on inadequate observational science. Fisheries management has relied on models based on fishery-dependent data and far too limited real-world verification. Oceanographic programs have been primarily bottom-up oriented. However, linkages between various trophic levels are simply too weak, and too much error is propagated through the ecosystem for this approach to be effective in understanding the status of upper trophic levels, including fishes, sea birds and marine mammals. We present an alternative approach to address the deficiencies of historic ocean and fisheries policy. The foundation of this approach is precision monitoring of the dominant biomasses of the ecosystem, based on high-speed, optimized sampling strategies and a new concept referred to as the "wasp waist" or middle-out forcing. This approach has been verified by research at the Prince William Sound Science Center (PWSSC) in Alaska. We have identified and focused on long-term assessment of the dominant biomasses, which include Pacific herring, walleye pollock and certain macrozooplankton. We were able to detect, separate and quantify the relative impacts of the 1989 Exxon Valdez Oil Spill and overfishing on the subsequent collapse of the PWS herring population. We have shown that the competition for dominance between Pacific herring and walleye pollock has major ramifications for the health of many seabirds and marine mammals, including the endangered Steller sea lion. We have shown that the Exxon Valdez Oil Spill indirectly harmed Steller sea lion and several seabird populations as a result of the subsequent collapse of the Pacific herring population. We have documented that pink salmon survival is strongly correlated with the abundance of dominant macrozooplankton. These successes have been achieved in a very limited program. Expanded application of these principles would overcome many of the current limitations of fisheries and ocean policy.