Seasonal Variability of Marine Fish Diversity in Relation to Water Quality of East Midnapore Coast of West Bengal, India

Marine fishes are one of the important factors in stabilizing the local aquatic ecosystem and regulating the nutritional socio-economy of local fisher folks. The recent increases in anthropogenic activity, pollution and overfishing have led to the decline of marine fish species richness and their local aquatic habitats. In this study we sought to determine the inter-relationship between water quality, anthropogenic activity, and fish landing stations through a 31 km stretch of the East Midnapore coast in West Bengal, India which is known for its tourist destinations. The study was conducted monthly on different trawler fish landing sites from Dec 2018 to Dec 2021. During this period, we took fish samples and identified them. We obtained water quality data regarding Sea Surface Temperature (SST), Concentration of Chlorophyll-a (Chl-a), Turbidity, and Dissolved Oxygen (DO) in order to identify further correlation between the water quality analysis and species diversity. 154 numbers of commercially important marine fish species were documented. As per the IUCN database, 13% of the total fish species fall under the red list category and 16% of the species reveal a decreasing population trend. The availability of those red-listed fish throughout the season has been shown in the matrix plot to detect their gradual decrease in sighting. After analyzing the water quality data, we found out that DO, SST, Turbidity, and Chl-a correlate with the species richness on some sites and the water parameters are also differs during the seasons. Both fish species richness and water quality have been affected on those fish landing sites which have been subject to heavy anthropogenic loads.