Affiliations: Institute of Environmental Studies and Wetland
Management, Department of Environment Govt. of West Bengal, Salt Lake City,
Kolkata – 700064, India | Department of Environmental Science, University of
Calcutta, Kolkata – 700019, India | Ecology Research Unit, Zoology Department, University
of Calcutta, Kolkata – 700019, India | Raja N.L. Khan Women's College, Midnapore,
West Bengal | Syamaprasad College, Kolkata, India
Abstract: Current study deals with the phytoplankton structure and seasonal
variation in Mathura Beel (wetland), a floodplain lake in Gangetic plane of
West Bengal, India. The generic composition of phytoplankton was studied
monthly during August 2008 to February 2011. All the relevant calculations were
done according to three seasons viz. pre-monsoon, monsoon and post-monsoon. A
total of 96 species belonging to 87 genera were identified under six algal
classes. Chlorophyceae showed their maximum species diversity with 45% whereas
the Cyanophycean algae showed maximum relative density i.e. 93.11% throughout
the study period with Microcystis aeruginosa (45.08%) followed by Aphanocapsa
rosena (15.53%). Phytoplankton species of Bacillariophyceae, Euglenophyceae,
Xanthophyceae and Dinophyceae were negligible in number. Maximum and minimum
phytoplankton diversity was found in post-monsoon (H' = 0.38) and pre-monsoon
(H' = 0.09) respectively. Cyanophycean algae (D = 0.97) dominated in pre-monsoon
season. The temperature increased upto 2°C in pre-monsoon season during the
study period. Dominance of cyanophycean algae (Microcystis sp.) has been found
to be the main reason of eutrophication in Mathura beel.
