Vol. 41 No. 1, 2002

Summer Spatial Distribution of Copepods and Fish Larvae in Relation to Hydrography in the Northern Taiwan Strait

Chih-Hao Hsieh and Tai-Sheng Chiu*

Department of Zoology, National Taiwan University, Taipei, Taiwan 106

Chih-Hao Hsieh and Tai-Sheng Chiu (2002) This study analyzed the spatial distribution of copepods and fish larvae in relation to hydrographic conditions in the northern Taiwan Strait during summer as the prevailing southwestern monsoon drives the surface warm water from the South China Sea into the Strait and causes subsurface water upwelling in the west. Cluster analysis based on copepod and fish larvae assemblages resulted in recognition of 4 groups, of which 3 major ones conformed to the hydrography. The western Taiwan Strait group was characterized by coastal and neritic species, the East China Sea group was dominated by oceanic species, and the eastern Taiwan Strait group consisted of both neritic and oceanic species. Analysis of dominant species also supports this result. Copepod abundance was positively related to water temperature and dissolved oxygen. The area of high copepod abundance did not correspond to the area of high primary productivity in the upwelling area, but occurred at a stable area downstream of the upwelling. Fish larva abundance was positively related to copepod abundance.

Key words: Species composition, Southwestern monsoon, South China Sea, East China Sea, Upwelling.

*Correspondence: Tel: 886-2-2363-0231 ext. 2128. Fax: 886-2-23634014.