Seasonal variation in fishery diversity of some wetlands of the Salcete Taluka, Goa, India

238-247 Status of fishery potential of three coastal wetlands, Salcete Taluka viz. Betul Assolna Velim wetland, Loutolim Raia Ambora wetland and Curtorim Macazana wetland in relation to prevailing environmental parameters viz. surface water temperature, DO, salinity and pH were examined. Twenty two species of fin fishes of commercial importance were recorded during the study in the three wetlands which showed seasonal variations in abundance. Average fish catch in these wetlands ranged from 20 to 100 kg.day-1 comprising mainly of Etroplus spp (pearl spots), Sillago sihama (silver whiting), Mugil cephalus (grey mullet), Lutianus argentimaclatus (red snapper), Lates calcarifer (sea bass), Channos channos (milk fish) and Gerres spp. Average fish catch was higher in Betul Assolna Velim wetland, followed by Loutolim Raia Ambora wetland, and Curtorim Macazana wetland. During the monsoon and pre-monsoon seasons, higher species diversity of fish was recorded at Betul Assolna Velim wetland and Loutolim Raia Ambora Wetland compared to the Curtorim Macazana wetland. Betul Assolna Velim wetland fishery also showed relatively higher evenness values during all seasons. Cluster analysis showed species like Sillago sihama, Mugil cephalus, and Etroplus spp. were recorded in all three wetlands in large numbers throughout the year while Johnius dussumeri and Megalops cyprinoides appeared only during the post monsoon season in the Curtorim Macazana wetland. Trichiurus savala was absent during the post monsoon season in all the three wetlands. Salinity appears to be a major factor influencing the abundance and diversity of fin fish species in these wetlands.