Abundance and distribution of phytoplankton in Bhutnal Lake, Vijayapur, Karnataka

Abstract

Phytoplankton abundance and distribution are of ecological importance, as they are very sensitive to change, therefore Phytoplankton make ideal indicators of aquatic ecosystem. Phytoplankton in lake ecosystem acts as primary producers and forms a bulk of food for zooplankton, fishes and other organisms. The present work aims to study the Phytoplankton seasonal distribution and diversity in Bhutnal lake Vijayapur for the period of one year from June 2017 to May 2018. Throughout the study period, 45 different Phytoplankton genera belonging to 4 groups were observed with a complete domination from Chlorophyta (52.76%) followed by Cyanophyta (26.65%), Chrysophyta (16.61%) and Rhodophyta (3.96%). Phytoplankton population density attained its maximum (999 No./l) during winter season and minimum during monsoon season (56 No./l). Phytoplankton biomass (wet weight) varied from 0.6 mg/l during Monsoon to 3.0 mg/l during winter and Dry weight varied from 0.11 mg/l during monsoon to 1.95 mg/l during winter. Considerably low phytoplankton population was observed during the monsoon and this could be due to the heavy rain fall, excessive flooding, increased water volume, cloudy weather, low transparency, low temperature and low pH.