Relationship between the saury fishing ground and sea surface oceanographic features determined from satellite data along the northeastern coast of Japan

Relationship between the distributions of sea surface temperature in the formation of the saury fishing ground has been reported by many studies. However, it is not clear whether the saury fishing ground is related to the boundary of water masses and the chlorophyll-a concentration. We used the satellite images to retrieve the temperature gradients and chlorophyll-a concentration, and studied further in conjunction with simultaneously collected saury fish catch data. The saury fishing ground east off Hokkaido (Japan) was closely related to the temperature gradient characterized by 0.8-2.0 degree C/km. In the meantime the fishing ground off Sanriku was closely related to chlorophyll-a concentration level of 0.6-1.6 mg/m super(3). The fact that the formation of the saury fishing ground is related to the boundary of water masses and the chlorophyll-a concentration has been proved clearly in this paper.