Remote sensing of sea surface temperature and chlorophyll-a: implications for squid fisheries in the north-west Pacific Ocean

The spatio-temporal relationship between sea surface features and squid catch rates in the north-west Pacific Ocean were studied. Thermal-colour features were extracted from long-term Advanced Very High Resolution Radiometer (AVHRR) (1995-2001) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data (1997-2001). Productive squid fisheries coincided with locations having high sea surface temperature (SST) variability near Hokkaido. Maps of squid fishery migration and basin-wide sea colour fronts in the Kuroshio-Oyashio convergence region were compared. In the peak fishing season (July to August), the fisheries coincided with the steep sea colour gradients between 0.15 and 0.5 mg m-3. In the autumn season (September to October), the fishing ground migrated to the northern part of the sea colour fronts, locating along the 0.5 mg m-3 isoline, which marked the interface between cold and warm water enriched in food for squid.