Studies on Limnological Parameters and their Impact on the Distribution and Diversity of Zooplankton in Anchar Lake, Kashmir

Abstract

The transfer of energy from producers to consumers, such as fish, fish larvae, and invertebrates, is facilitated by zooplankton. Consequently, zooplankton play a crucial part in the productivity and functioning of aquatic ecosystems, and they are also involved in the application of several emerging environmental management concepts, such as Environmental Impact Assessment (EIA), bioindication of pollution, and biomonitoring. To analyse the present condition of the Anchar Lake, this research was conducted to investigate the zooplankton association, their abundance, richness, diversity (Cladocera and Rotifera), and their seasonal fluctuations in connection to limnological factors. Four sampling sites were used to examine thirteen physicochemical parameters along with the abundance of zooplankton from January 2019 to December 2020. During the present investigation, significant variation (p < 0.05) was observed in transparency (trans), dissolved oxygen (DO), pH, electrical conductivity (EC), total alkalinity (TA), nitrate-nitrogen (NO3-N), total hardness (TH), and total phosphorus (TP) between the different sites of Anchar Lake, whereas non-significant variation was observed in air temperature (AT), water temperature (WT), free carbon dioxide (FCO2), chloride (Cl-), and nitrite-nitrogen (NO2-N). The results further revealed a total of 44 zooplankton species, belonging to two: Rotifera (27 species) and Cladocera (17 species). The zooplankton diversity was found to vary on spatiotemporal scales showing maximum values for the Shannon diversity index in the case of Cladocera during spring (2.63±0.25) and for Rotifera during summer (2.53±0.25) whereas, minimum diversity values were recorded during winter for both Cladocera and Rotifera (1.54±0.44 & 1.47±0.54 respectively). On the spatial scale, site-A2 showed maximum diversity of Cladocera (2.3±0.21), while site-A4 showed maximum diversity of Rotifera (1.99±0.03). The influence of physicochemical parameters on zooplankton distribution and diversity provides a detailed picture of the impact of pollution load in Anchar Lake.