Assessment of Faunal Biodiversity and Its Ecological Role in the Yamuna River, Delhi NCR, India

Abstract

The Yamuna River is an ecologically important freshwater system that is increasingly affected by urbanisation, sewage discharge, industrial effluents, and other anthropogenic pressures. Such disturbances can alter water quality and adversely affect aquatic communities. Because fish, zooplankton, macroinvertebrates, and benthic fauna respond to changes in environmental conditions, their diversity and distribution can provide useful indications of river ecosystem health. The present study was conducted to comparatively assess faunal diversity, water quality, and anthropogenic disturbance at three selected sites along the Yamuna River: Palla Ghat, Jhangola Ghat, and Kashmiri Gate Ghat. The findings revealed considerable spatial variation in aquatic faunal diversity and environmental conditions among the study sites. Palla Ghat recorded high faunal diversity, good water quality, and low anthropogenic disturbance, indicating relatively favourable conditions for aquatic organisms. The fish community included Labeo rohita (Rohu), Catla catla (Catla), Cirrhinus mrigala (Mrigal), Channa spp., and Clarias spp. The zooplankton community comprised rotifers, cladocerans, and copepods, while macroinvertebrates and benthic fauna included oligochaetes, chironomid larvae, molluscs, and other aquatic invertebrates. Jhangola Ghat exhibited moderate faunal diversity, moderate water quality, and moderate anthropogenic disturbance. Its fish assemblage was represented mainly by Labeo rohita, Catla catla, and Cirrhinus mrigala, along with rotifers, cladocerans, copepods, annelids, molluscs, insect larvae, and other benthic organisms. In contrast, Kashmiri Gate Ghat showed low faunal diversity, poor water quality, and high anthropogenic disturbance. The fish community was comparatively limited, with Labeo rohita and Catla catla recorded, while the zooplankton community was dominated by cladocerans and copepods, and the benthic community consisted mainly of insect larvae and other benthic organisms. Overall, the study demonstrates a clear association between water quality, anthropogenic pressure, and aquatic faunal diversity.