Study on the Temporal Variation of the Bacillariophyceae and Chlorophyceae in A Tropical Wetland of Chapra, Bihar

Bacillariophyceae were the most dominant group of phytoplankton. At site 1, this group was represented by 2 genera. The minimum number during two years of study was in May, 2012 (48 unit/L) and October, 2012 (202 unit/L) While the maximum population density (1790 unit/L) was recorded in January, 2012 and April, 2013 (1154unit/ L) in both the years. The seasonal abundance of phytoplankton showed that the cyclotella sp of Bacillariophyceae was poorly populated and scarcely encountered during the entire study period, the lowers number (2 unit/L) was recorded during several months while the highest in January, 2012 and 2013 (74 and 82 unit/L) during their respective annual cycles. Synedra ulna was the most dominant phytoplankton found abundantly throughout the year except occasionally they were not present, the minimum number (6 unit/L) was observed in April, 2012 and August, 2013 (2 unit/L) whereas the maximum number (998unit/L) was noticed in December, 2012 and April, 2013 (446 unit/ L) their occurrence did not depict any fixed seasonality.