Climate Change and Pacific Salmon Abundance
Salmon catch in Alaska fluctuates on interannual and interdecadal time scales. Downton, in collaboration with Miller, studied the effect of variability in North Pacific climate on Alaskan commercial catch of sockeye, pink, and chum salmon from 1925 to 1994. Controlling for climatic shifts in the 1940s and 1970s, they used multivariate time series models to show that the interannual variability in the catch of each species is related to surface temperatures in particular large regions of the eastern North Pacific. In addition, the models show a significant positive relationship of chum catch to pink catch two years earlier, suggesting a common influence on smolts of the two species. The results support the contention that salmon production is affected by climatic changes on both interannual and interdecadal time scales. A paper on this work is in press in the Canadian Journal of Fisheries and Aquatic Sciences.
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Transboundary Fisheries: Pacific Salmon
Miller continued work on a project analyzing the impacts of climate-related variations on Pacific salmon abundance on the international management of these resources. The US and Canada attempt to manage their harvests of five Pacific salmon species under the terms of the 1985 Pacific Salmon Treaty. However,
since 1993 they have been unable to agree on a full set of harvesting regime. In previous work, Miller demonstrated that climate-driven trends in stock abundance destabilized the hoped-for cooperation and have contributed to the continuing impasse between the two countries.
During FY98, Miller submitted two papers for publication and gave five professional talks on this subject. In addition, she has obtained funding from NOAA/OGP to extend this work by developing a more realistic, game-theoretic representation of the institutional process by which the US and Canada attempt to negotiate harvest allocation agreements for salmon stocks covered by the Pacific Salmon Treaty. The NOAA-funded project also calls for documenting the use of climate-related information throughout the history of the negotiations. This project involves collaboration with Gordon Munro (U British Columbia) and Robert McKelvey (U Montana). Miller and her colleagues have started a series of interviews with fishery management officials and high-level national negotiators to collect the historical information and to provide guidance to the modeling effort.
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