Limnological Assessment of Chhattisgarh's Aquatic Ecosystems with Special Focus on Fish Diversity: A Review

Abstract

Despite the ecological and socio-economic significance, the limnology and fish biodiversity of Chhattisgarh have not received commensurate scientific attention. The state's aquatic ecosystems support remarkable biodiversity that remains systematically under-studied relative to its ecological and socio-economic significance. This review synthesises published information on the physicochemical properties, biological communities, and ichthyofaunal diversity of Chhattisgarh's water bodies, integrating findings from regional, national, and international scholarly sources. The physicochemical regime of the state's rivers and reservoirs exhibits pronounced seasonal variability, governed predominantly by the South-West monsoon, and is increasingly modified by anthropogenic perturbations including industrial effluents from coal-mining operations, agrochemical runoff, and urban wastewater discharges. The recorded fish fauna encompasses species from at least 15 families and spans multiple trophic guilds, with the Cyprinidae, Bagridae, and Channidae constituting the most species-rich groups. Biologically significant taxa — including large- bodied mahseers (Tor spp.) and the clown knifefish (Chitala chitala) — have undergone documented population contractions owing to habitat degradation and overexploitation. Plankton communities, macrophyte assemblages, and benthic invertebrate fauna reflect the trophic gradient of individual water bodies, ranging from oligotrophic montane streams of the Bastar plateau to hypereutrophic periurban water bodies near Raipur and Korba. Critical lacunae persist in long-term limnological monitoring, molecular-level phylogenetic assessment, and quantitative fisheries surveys. This review identifies priority research areas and proposes integrated, landscape-scale conservation strategies to safeguard the aquatic heritage of Chhattisgarh within the broader context of India's freshwater biodiversity crisis. An integrated, basin-scale approach to aquatic resource management, grounded in ecological flows, freshwater protected areas, community co-management, and pollution control, offers the most promising pathway to securing the long-term viability of Chhattisgarh's aquatic biodiversity.