Study on seasonal variation of Dissolved Oxygen (DO) and its impact on zooplankton density in a fishery pond in Birbhum District, West Bengal, India

Abstract

The present investigation was carried out month wise at different sites of a fishery pond in Birbhum district, West Bengal for a period of 10 months from September 2022 to May 2023. High dissolved oxygen (DO) was found during late winter months due to efficient photosynthetic activity of rich phytoplankton in water that support greater density of zooplankton. The minimum DO level was found due to evaporation as temperature increases during summer months and hence zooplankton density decreases. Dissolved oxygen varies from 4.70 to 16.20 mg/L. during the study period. Highest DO was found in February, 2023 and lowest during August, 2022. Highest density of zooplankton was found in the month February, 2023 and lowest in August, 2023. There is strong correlation between dissolved oxygen content in pond water and the zooplankton density with Spearman’s correlation coefficient value 0.9587(close to 1.0).