Comparative Zooplankton Diversity in Two Freshwater Lakes of Belagavi City, Karnataka, India

Zooplankton are used as bioindicators to assess the pollution status of lakes but diversity studies related to different trophic levels of lakes are few. Therefore, the present study was undertaken to assess the comparative zooplankton diversity of a eutrophic Kanbargi lake and an oligotrophic Khadarwadi lake in Belagavi city. During the study period, a total of 23 species of zooplankton were identified. In Kanbargi lake, Rotifera showed maximum diversity and abundance, followed by Copepoda, Ostracoda and Cladocera while in Khadarwadi lake, Rotifera were most abundant followed by Cladocera, Copepoda and Ostracoda. Rich diversity and abundance of Rotifera were observed in Kanbargi lake compared to Khadarwadi lake, while Cladocera abundance was higher in Khadarwadi lake. Least abundance was shown by Ostracoda in both lakes. Seasonal variation was also observed between the two lakes, with Rotifera dominating the summer season, while Copepoda and Cladocera abundance increased during the monsoon season. Hierarchical Cluster Analysis (HCA) reveals different clusters occupied by zooplankton in both lakes. These results suggest that there exists a difference in zooplankton diversity and community structure between the two lakes. The current study highlights the potential implications for broader aquatic ecosystem and importance of monitoring the freshwater bodies to maintain ecological balance.