Seasonal Dynamics of Water Quality and Zooplankton Diversity in Tripuranth Lake, Basvakalyan, Karnataka: A Year-Long Assessment of Ecosystem Health and Environmental Drivers

Abstract

Tripuranth Lake serves as a vital freshwater ecosystem in Basavakalyan, Bidar District, Karnataka, providing essential services for irrigation, fisheries and biodiversity conservation. This investigation evaluated the seasonal dynamics of water quality and zooplankton communities through comprehensive monthly monitoring from January to December 2023. Ten key physico-chemical parameters were analyzed, including atmospheric temperature (21.5-36.8°C), water temperature (18.25-28.50°C), pH (6.45-9.35), dissolved oxygen (6.18-9.25 mg/L), total dissolved solids (120.50-210.80 mg/L), conductivity (158.50-315.80 µS/cm), total alkalinity (88.50-248.60 mg/L), total hardness (58.20-208.50 mg/L), calcium (13.80-28.50 mg/L), and magnesium (6.20-32.80 mg/L). Zooplankton diversity assessment revealed 28 species distributed among Rotifera (11 species, 39.3%), Cladocera (8 species, 28.6%), Copepoda (6 species, 21.4%), and Ostracoda (3 species, 10.7%). Maximum parameter values occurred during pre-monsoon months (April-May), with water temperature peaking at 28.50°C, pH at 9.35, and conductivity reaching 315.80 µS/cm. Zooplankton abundance exhibited strong positive correlations with temperature (r = 0.82) and dissolved oxygen (r = 0.73), indicating temperature-driven productivity patterns. The lake demonstrated good water quality standards suitable for multiple uses, while zooplankton diversity indicated a healthy, functioning ecosystem with seasonal adaptation strategies.