Effect of monsoon on coastal fish diversity of Goa: an example from the gillnet fishery

Abstract

The dynamics of fauna in coastal ecosystems are influenced by seasonal patterns in the oceanographic environment. It is well known that the monsoon along south-west coast of India influences the movement and spawning of fishes. Thus, they have direct effect on the richness, abundance and evenness of fish diversity in the ecosystem. This study investigates how the monsoon affects the commercial gillnet fishery along the coast of Goa. Fishing experiments were conducted in popular gillnet fishing grounds and the temporal pattern in diversity indices between October 2013 and September 2014 was assessed. A total of 124 fish species (40 families), 16 crustacean species (4 families) and 9 molluscan species (8 families) were recorded. The species diversity was found to be significantly different during the monsoon season and the species abundance distribution followed a geometric series during this period indicating signs of ecosystem perturbations. The economic and biological aspects of gillnet fishing in relation to the monsoon season in Goa are also discussed.