Under water visual census of reef fishes in Tuticorin group of islands, Gulf of Mannar, Southeastern India

Abstract

Reef fishes are integral part of coral reef ecosystem as they play major role in ecological balance. Visual census of fish assemblages on coral reefs in the vicinity of four islands in Tuticorin group, Gulf of Mannar, Southeast coast of India was conducted between August 2011 and November 2012. Under water data collection on reef fish abundance and diversity was done by following belt transect method involving scuba diving. A total of 78 species from 24 families were recorded during the study period. . Kariyachalli Island was recorded the highest density and diversity of reef fishes (64 species) among the four islands and this dominance is corroborated to the comparatively higher live coral cover (46.61%). The study reveals that habitat complexity determines the abundance and diversity of reef fishes in a reef area. Presently, anthropogenic and natural factors threaten coral reefs and protection of reef habitat is inevitable for the survival and existence of reef fishes and ultimately the livelihood of the dependant people.