Assessment of Fish Diversity Associated with Water Quality Parameters of Burhi Gandak River, North Bihar, India

Burhi Gandak River is a left-bank tributary of River Ganga and a major riverine ecosystem in North Bihar. The river is home to different freshwater fish species, gastropods, bivalves, and other aquatic animals. The fish diversity and Water quality parameters data were collected in six sampling locations from the period of August 2020 to June 2021. The present study examined fish diversity and their relationship with water quality parameters. The study revealed that Burhi Gandak River is the home of 71 fish species (67 indigenous and 4 exotic species). Identified species belong to 28 families, 10 orders, and 52 genera. The Order Cypriniformes contributes (45%) and 19 fish species belonging to the family Cyprinidae constitute the major diversity of the river. The maximum number of species was documented from location S4 (Pusa) and minimum from S2 (Muzaffarpur) respectively. The four types of diversity indices i.e., Shannon–Wiener (2.886 to 3.206), Simpson’s (0.9235 to 0.9449), Margalef’s richness (4.768 to 6.82) and Pielou’s evenness (0.4935 to 0.5708) were also assessed, and values of diversity indices vary from each location. Canonical correspondence analysis (CCA) indicates that pH, free CO2, water temperature, and dissolved oxygen were the key water quality parameters in the Burhi Gandak River. Four exotic species namely Ctenopharyngodon idella, Barbonymus gonionotus, Carassius carassius and Cyprinus carpio were recorded. According to the IUCN RedList, out of 71 fish species, 4 Near Threatened (NT), 1 Vulnerable (VU) and 66 Least Concern (LC).