Spatial and temporal variations of the estuarine larval fish community on the west coast of Taiwan

Spatio-temporal variations in the distribution and community structure of the estuarine larval fishes on the west coast of Taiwan was examined in the estuaries of Shuangchi Creek (SC), Gongshytyan Creek (GST), Tatu Creek (TT) and Tongkang River (TK). Fish were collected by a net (mesh 0.8-1.8 mm) set against the flood tide at night during the new- and full-moon periods from September 1997 through December 1998; 28-49 families (56-94 species) were collected from the four estuaries. Fish larvae were abundant from spring to autumn. Fish communities differed among estuaries: Mugilidae were the most abundant in SC, Terapon jarbua in GST, Stolephorus insularis in TT and Ambassis urotaenia in TK. The 15 most dominant species constituted 88-94% of the total catch. The relationship of fish abundance and species diversity to water temperature and salinity differed among estuaries. Species composition could be classified into northern (SC, GST winter and TT winter) and southern (TK, GST summer and TT summer) groups. The species composition of the larval fish communities was more diverse in spring-autumn than in winter, and in southern than in northern estuaries. Monsoon-driven coastal currents may influence seasonal dispersal and community structure of the estuarine larval fishes on the western coast of Taiwan.