The Spatial and Temporal Disparity of Fish Assemblage and Its Association with Environmental Factors Through Multivariate Statistical Analysis in Jammu and Kashmir's Himalayan River System.

Abstract

The goal of this study was to explore the dynamics of the environmental components with fish species assemblages in the Ravi and Chenab rivers of the Himalayan river system during the study period from "July 2020 to June 2021".. To examine the relationship between fish species and environmental parameters, multivariate statistical analyses including canonical correspondence analysis, principal component analysis and cluster analysis were applied to data from fish species. ANOSIM and SIMPER were used to determine whether fish assemblage varied with seasons or streams and to identify the fish species that contributed to this variation between the sampling sites. To study the effect of environmental factors on fish species richness, multiple regression analysis was used. Fish species belonging to 30 species and 12 different families (Cyprinidae, 66.6%) were recorded from three study sites (Bhini, Jhajjar and Chadwal streams) with Chadwal (34.3%) having the most ichthyofaunal population. Hillstream fish species dominated the Bhini stream, while catfish species dominated the Jhajjar stream. The Chadwal Stream was home to a diversity of fish species due to its vast fishing grounds. The values of free carbon dioxide (FCO2), bicarbonates (HCO3-), and habitat structure showed significant variations (p<0.05). The Shannon-Wiener (H'), Simpson dominance, and Margalef index values of fish communities were high. Differences in environmental parameters in each sampling site influenced the fish population in the present study. Our findings showed that environmental factors influenced species composition and provided evidence for the dynamic interaction between environmental variables and fish assemblage in the Ravi and Chenab rivers.