Cyclic climate changes and fish productivity

Abstract

The book considers relationships between climate changes and fish productivity of oceanic ecosystems. Long-term time series of various climatic indices, dynamics of phyto- and zooplankton and variation of commercieal fish populations in the most productive oceanic areas are analyzed. Comparison of climate index fluctuations and populations of major commercial species for the last 1500 years indicates on a coherent character of climate fluctuations and fish produciton dynamics. A simple stochastic model is suggested that makes it possible to predict trends of basic climatic indices and populations of some commercial fish species for several decades ahead. The approach based on the cyclic character of both climate and marine biota changes makes it possible to improve harvesting of commercial fish stocks depending on a phase (ascending or descending) of the long-term cycle of the fish population. In addition, this approach is helpful for making decisions on long-term investments in fishing fleet, enterprises, installations, etc. The results obtained also elucidate the old discussion: which factor is more influential on the long-term fluctuations of major commercieal stocks, climate of commercial fisheries?