Responses of Japanese anchovy catch to environmental changes in the South Sea of Korea in recent decades: a generalized additive model approach

Abstract

Japanese anchovy (Engraulis japonica) is commercially and biologically important small pelagic fish in Korea. In relation to a decrease in the production of coastal fisheries in Korean waters in recent years, the understanding of a relationship between fish resources and environmental factors of their habitat can help establish the strategies of fisheries management. This study investigates the relationships between anchovy catch and ocean environment during 1980-2010 in the South Sea of Korea, the main fishing ground of anchovy in Korea, by applying a generalized additive model (GAM) to primary/secondary production and oceanographic data including temperature and salinity. Based on GAM results shows that the zooplankton biomass, mixed layer depth, 5m depth seawater temperature, and Arctic Oscillation Index explain a large part (more than 80%) of variability of annual anchovy catchment. This finding suggests that in recent three decades, zooplankton biomass is a main contributor to the interannual variability of anchovy catchment in the South Sea of Korea.ship between fish resources and environmental factors of their habitat can help establish the strategies of fisheries management. This study investigates the relationships between anchovy catch and ocean environment during 1980-2010 in the South Sea of Korea, the main fishing ground of anchovy in Korea, by applying a generalized additive model (GAM) to primary/secondary production and oceanographic data including temperature and salinity. Based on GAM results shows that the zooplankton biomass, mixed layer depth, 5m depth seawater temperature, and Arctic Oscillation Index explain a large part (more than 80%) of variability of annual anchovy catchment. This finding suggests that in recent three decades, zooplankton biomass is a main contributor to the interannual variability of anchovy catchment in the South Sea of Korea.