Long-term climate change and main commercial fish production in the Atlantic and Pacific

Main Atlantic and Pacific commercial species of the subtropic, subarctic and arctic zones - Atlantic and Pacific herring; Atlantic cod; European, South African, Peruvian, Japanese and Californian sardine; South African and Peruvian Anchovy; Pacific salmon; Alaska pollock; Chilean jack mackerel and some others - undergo long-term simultaneous oscillations. The total catch of these highly abundant species equals about 50 percent of the total Atlantic and Pacific marine fish harvest. The dynamics of northern hemispheric surface air temperature anomaly (dT) can hardly be correlated with long-term dynamics of marine commercial fish production because of high inter-annual variability. The so called atmospheric circulation index (ACI) characterizing a dominant direction of air mass transport was found to be closely related with long-term fluctuations of the main commercial stocks. This index has been registered over the Northern Hemisphere or more than 100 years using the Wangengeim-Girs method. Correlation coefficients between commercial catches and ACI dynamics in the period of 1900-1994, stayed in the range of 0.70-0.90. The global character of the ACI dynamics is confirmed by its close correlation with such global geophysical characteristics as the earth rotation velocity index (ERVI). Approximately 50-70 year simultaneous cycles were observed in stock dynamics of the main commercial species, ACI and ERVI. The dynamics of main commercial stocks in both Atlantic and Pacific follow the alternation of the so-called circulation epochs (meridional or 'latitudinal'). The long-term changes of dT, ACI, ERVI and commercial stock dynamics display the beginning of new climate-production phase similar to that of 1950-1970s. (C) 1998 Elsevier Science B.V. All rights reserved.