Spatial pattern analysis of zooplankton community of Bakreswar reservoir, India

Rural populations often depend on small reservoirs for their water supply. These reservoirs are engineered systems designed to serve specific purposes. Water from these sources is not only utilized for drinking purposes, but also for commercial and industrial use. Thus, a thorough limnological study is essential. The present study is carried out at Bakreswar reservoir in Birbhum district, which was created by the dam, built on Bakreswar River. The major purpose of the reservoir is to supply drinking water to the surrounding villages and to use Bakreswar Thermal Power Station for cooling their power plant. A previous study on this reservoir has shown temporal variation of environmental factors as well as good assemblage of zooplankton. In order to get a more detailed preview on zooplankton groups, seasonal diversity is calculated for four major groups of zooplanktons (Cladocera, Ostracoda, Copepoda and Rotifera) with the software PAST. Spatial pattern analysis of zooplankton community is also performed to propose possible hypotheses explaining reasons underlying the causal factors for any such variation. Moreover, community ordination is done using SPSS 20 to understand the overall ecosystem functioning of the reservoir. The results show that Station I and Station III are more diversified in all the seasons compared to Station II. The mode of distribution is clumped, and the degree of clumping varied with different functional groups of studied zooplankton as seen in the two methods used. So it can be concluded that the zooplankton community of this reservoir is diverse and shows horizontal clumped distribution pattern and niche separation among the groups to avoid competition. The results help in formulating proper strategies for advanced water quality management and conservation of reservoir ecosystem.