Pacific salmon: climatelinked long-term stock fluctuations

The impact of large-scale climate change on the salmon productivity of the North Pacific is an important scientific and economical problem. Commercial catching may not always be a good indicator of abundance, but for larger aggregations of stocks we suppose that catches represent the abundance trends of the total aggregate (Beamish and Bouillon, 1993). Reliable information on the trends of commercial catch is necessary to estimate the carrying capacity of the North Pacific for salmon. The commercial catches have been collected for more than 70 years, but the statistics of salmon catches in the 20-40s needs to be substantially corrected. (Klyashtorin and Smirnov, 1992, 1995; Chigirinsky, 1994). The dependence of the long-term fluctuations of Pacific salmon abundance on climate changes was demonstrated recently by a number of papers (Beamish and Bouillon, 1993, Klyashtorin, and Smirnov, 1995). Nevertheless, reliable predictive climatic indices for salmon dynamics still have not been determined. The main purposes of this paper are the following