Pacific Basin climate variability and patterns of Northeast Pacific marinefish production

A review of oceanographic and climate data from the North Pacific and Berin g Sea has revealed climate events that occur on two principal time scales: a) 2-7 years (i.e. El Nino Southern Oscillation, ENSO), and b) inter-decada l (i.e. Pacific Decadal Oscillation, PDO). The timing of ENSO events and of related oceanic changes at higher latitudes were examined. The frequency o f ENSO was high in the 1980s. Evidence of ENSO forcing on ocean conditions in the North Pacific (Nino North conditions) showed ENSO events were more f requently observed along the West Coast than in the western Gulf of Alaska (GOA) and Eastern Bering Sea (EBS). Time series of catches for 30 region/sp ecies groups of salmon, and recruitment data for 29 groundfish and 5 non-sa lmonid pelagic species, were: examined for evidence of a statistical relati onship with any of the time scales associated with Nino North conditions or the PDO. Some flatfish stocks exhibited high autocorrelation in recruitmen t coupled with a significant step in recruitment in 1977 suggesting a relat ionship between PDO forcing and recruitment success. Five of the dominant g adid stocks (EBS and GOA Pacific cod, Pacific hake and EBS and GOA walleye pollock) exhibited low autocorrelation in recruitment. Of these, Pacific ha ke, GOA walleye pollock and GOA Pacific cod exhibited significantly higher incidence of strong year classes in years associated with Nino North condit ions. These findings suggest that the PDO and ENSO may play an important ro le in governing year-class strength of several Northeast Pacific marine fis h stocks. (C) 2001 Published by Elsevier Science Ltd.