Long-term spatiotemporal variation in Miyazaki Prefecture coastal fishery catch in relationship to oceanographic conditions

Abstract

To identify spatiotemporal variations in the coastal resources off Miyazaki Prefecture, we analyzed fisheries catch data for 15 species over 40 years. Additionally, we examined the long-term relationship with oceanographic conditions, taking into consideration the influx of nutrient-rich cold water into the bottom layer of the Bungo Channel. Of the 14 species for which catch was found to correlate with tide levels at Hososhima (Miyazaki), catch for 10 species increased at low tides in conjunction with lower bottom temperatures, while that of the four remaining species increased at high tides. Furthermore, coastal fisheries catch in Miyazaki Prefecture was significantly synchronized with catch for 10 out of 15 species in the Southern Pacific Ocean, which was the highest among the four other maritime zones. Overall, these findings suggest that coastal resource catch in Miyazaki Prefecture is strongly affected by long-term variations in oceanographic conditions on the North Pacific scale, mainly in the form of nutrient-rich cold bottom water, whose influx increases Miyazaki coastal resources.