Catch of the firefly squid Watasenia scintillans in Toyama Bay was predicted by a multiple regression model using environmental factors. The relationship between annual catch, monthly average water temperature and monthly freshwater input into Toyama Bay was examined by simple regression analyses, and the most parsimonious multiple regression model was selected by Akaike Information Criterion (AIC). Using the multiple regression model, future catch was predicted. The goodness of fit between the actual and predicted catches was examined from the sum of residual squares. The results showed that the annual catches of this species are well explained by the surface water temperature in February of the previous year and the surface water temperature in April of the fishing year. Catches from 1993 to 1995 could be well predicted using the most parsimonious regression model estimated from the data set of the previous five years (1988-1992).
