Interrelationship between limnological parameters of a floodplain lake in Dwarkeshwar river basin and their impact on fish biodiversity

Abstract

Present study was designed to figure out the correlation between the physicochemical amplitude of the tropical lake Ray Pukur with its ichthyofaunal diversity in the region of the Dwarkeshwar River Basin. Water samples were collected on monthly basis over two years (March 2019 to February 2021) and selected physical and chemical variables including water temperature, transparency, pH, total alkalinity, total hardness, dissolved oxygen, carbon dioxide, biological oxygen demand, nitrates and phosphates were measured every month at four selected sites in this wetland. Results of principal component analysis revealed that water temperature (-0.878), dissolved oxygen (-0.803), and pH (0.747) were the key parameters and were considered the main ecological health determinants of this wetland. Altogether 22 self-recruiting fish species, representing 7 orders and 14 families were recorded. Order Cypriniformes was most dominating, with 5 species accounting for 52.84 percent of the catch composition, while Perciformes has 8 species accounting for 28.69 percent of the catch composition. Shannon Weiner diversity index of this wetland (2.36–2.47) indicates that the water quality of this lake is moderate. This study concludes that this wetland is perfect for aquaculture. Proper management is required in this wetland to maintain its sustainability in near future.