Hydrological And Water Quality Drivers Of Exotic Fish Assemblages In A Semi-Arid Indian Reservoir: A Multivariate Ecological Assessment

Abstract

Invasive alien species and damming - the most serious reasons for alterations in aquatic ecosystems - and understanding their interaction is essential for both conceptual and practical applications. Invasive alien species are a key factor in global ecological disruption, being the second most significant cause of species extinction. Simultaneously, establishment of dams has a negative impact on freshwater ecosystems, causing severe repercussions for aquatic species e.g. habitat loss, population decline and competition with native species. Our study of Thippagondanahalli reservoirs highlights the critical link between hydrological factors and exotic fish populations. Our findings indicate that the first two axes (RDA1 and RDA2) account for 82.2% of the total explained variance regarding the variation of seven exotic fish species in relation to fifteen hydrological variables. The research suggests that current hydrology and morphology conditions of the Reservoir and influenced by anthropogenic activities, is associated with the dominance of exotic fish species. Efforts are necessary to restore the natural hydro-morphology affected by damming in order to resolve the challenges posed by invasive exotic species effectively.