Effects of Changes in Sea Surface Temperature on Fluctuation in Larval Anchovy Resources in Coastal Waters of Taiwan

Abstract

Monthly CPUEs of larval anchovies and monthly sea surface temperature anomalies (SSTA) from 1981 to 1999 were analyzed with the spectral analysis and the harmonic function analyses for the northeastern and southwestern coastal waters of Taiwan. The results showed that f or 3.4- and 4.6-year cycles, CPUEs fluctuated with SSTA in the opposite phase in the southwest coastal waters, but had in-phase fluctuation in the northeast coastal waters. The autumn fishing season in the northeast waters had higher catch than that of the spring fishing season, with the Encrasicholina as the main species. In the southwest coastal waters, however, the catch in the spring fishing season was higher than that of the autumn fishing season, with the Engraulis japonicus as the main species. The Engraulis japonicus is a cold-water species, migrating with the China Coastal Current, whereas the Encrasicholina is a warm-water species migrating with the Kuroshio Current. CPUE and SSTA showed different phases in fluctuation between the two fishing grounds. Since 1990, Engraulis japonicus catch decreased while Encrasicholina increased in the southwest region.