Studies On Primary Productivity Of Gundalli Lake, Shahpur, Yadgir District, Karnataka

Abstract

This study evaluates the primary productivity of Gundalli lake, a freshwater reservoir in Shahpur, Yadgir District, Karnataka, vital for irrigation, aquaculture, and domestic use. Primary productivity, including Gross Primary Productivity (GPP), Net Primary Productivity (NPP), and Community Respiration (CR), was measured using the light and dark bottle method across five stations from February 2020 to January 2021. GPP peaked during pre-monsoon (0.98 gC/m³/hr) due to optimal light and nutrient conditions, while NPP was highest in post-monsoon (0.52 gC/m³/hr), reflecting efficient energy conversion. CR was highest in pre-monsoon (0.61 gC/m³/hr), indicating active metabolism. Monsoon seasons showed lowest productivity (GPP: 0.51 gC/m³/hr, NPP: 0.29 gC/m³/hr, CR: 0.22 gC/m³/hr) due to dilution and reduced light. Spatial variations highlighted higher productivity at the inlet station (0.82 gC/m³/hr) due to nutrient-rich runoff. The lake’s mesotrophic to eutrophic status suggests moderate to high nutrient levels, necessitating careful management to prevent eutrophication. These findings provide baseline data for sustainable aquaculture, nutrient management, and ecological conservation, supporting the lake’s role in regional socioeconomic sustainability.