Seasonal changes in location and water temperature of the fishing grounds by jigging fishery for flying squid, Ommastrephes bartrami (Lesueur), with some considerations on migration and occurrence of the fishing ground

Ommastrephes bartrami has been caught by jigging fishery as a substitute for Todarodes pacificus since 1974 and recently the catch has increased remarkably. The relationship between the fishing grounds of Ommastrephes bartrami and seasonal changes in water temperature for the four years from 1978 to 1981 were investigated from fishing statistics of Jigging fishery, reports from fishermen and published information on water temperatures. The migration and some factors for formation of fishing grounds were also studied