SUMMER ASSEMBLAGES OF ICHTHYOPLANKTON IN THE WATERS OF THE EAST CHINA SEA SHELF AND AROUND TAIWAN IN 2007

Abstract

This study investigated the relationships between assemblages of larval fish and hydrographic features in the East China Sea (ECS) and seas surrounding Taiwan during the summer of 2007. A survey was conducted from 2007 July 1 to 2007 July 11 in the ECS and from 2007 July 4 to 2007 July 16 in the waters surrounding Taiwan. A total of 12,670 larval fishes belonging to 95 families, 163 genes, and 189 species were identified. Engraulis japonicus and Sillago japonica were the 2 dominant species, accounting for 56.15% and 6.66% of the fish larvae samples. The cluster analysis results showed that the fish larval distribution patterns corresponded to hydrographic conditions. The results were also used to identify the following larval assemblages: the Kuroshio assemblage, coastal assemblage, Changjiang diluted water (CDW)/Yellow Sea mixed water assemblage, and Taiwan Strait water assemblage. The spatial distribution results showed a clear association between high abundances of larval fishes and shallow water areas near the ECS coast, and between low abundances and offshore Kuroshio water. The canonical correlation analysis results indicated that abundances of E. japonicus and S. japonica were strongly and positively correlated with chlorophyll a, but negatively correlated with salinity. These associations suggest that food sources and CDW might be crucial factors that determine the abundance and distribution of larval fishes during the summer.