Characterization of Fish Community Structure And Development of An Estuarine Fish Community Index For Temporarily Closed Estuaries (TCEs) From India’s Western Coast

Abstract

We present for the first-time data on fish assemblage structure for ten temporarily closed estuaries (TCEs) along the western coast of India. Fish community structure differed significantly between TCEs based on species presence/absence, estuarine use and feeding mode - differences based on estuarine surface area and geographical position (northern and southern locations). Marine migrant and freshwater stragglers dominated the ‘fish guilds’ in all estuaries, while piscivores and zoobenthivores were the major feeding guilds. We used the estuarine fish community index (EFCI) and a combined anthropogenic pressure index (CPI) to determine ecological quality of the TCEs. The application of functional guilds and EFCI could represent the use of TCEs by fish communities, and functional similarities existing between fish assemblages of these estuaries, despite considerable taxonomic, physical and chemical differences. Analysis of EFCI indicated that the ecological health of TCEs in south-western India ranges from “poor” to “good”. Through this index, we also established a significant relationship between CPI, EFCI and ecological quality in various TCEs (EFCI = A + (b X CPI)). Thus, the EFCI provides an integrated measure of the ecological status of fish community for TCEs along Indian coast.