FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

The fishing conditions of the anchovy larval fishery and the hydrographic environment in the waters off southwestern Taiwan were investigated during the period of January 2003 to May 2004. Temperature varied between 22.3 and 29.4 °C and salinity between 31 and 34.9 psu. The monthly catch varied between 1,155 and 71,755 kg and the catch per unit effort (CPUE) between 60.8 and 539.5 kg/day/boat. The anchovy larvae were dominated by Encrasicholina heteroloba and E. punctifer, which contributed 95% to the total number of larvae, while the larvae of Engraulis japonicus comprised less than 5%. The abundance of E. heteroloba and E. punctifer larvae changed with the water mass. Encrasicholina heteroloba was abundant when the South China Sea Warm Current prevailed, while E. punctifer was abundant when the Kuroshio Branch Current prevailed; the Kuroshio has a higher salinity than the South China Sea Warm Current. The monthly CPUE of larval anchovy was positively related to the temperature gradient of sea surface temperatures, and negatively related to the body length of the fish. The abundance of larval anchovy in relation to the zooplankton composition is discussed.