Seasonal variation in phytoplankton density of Bhagirathi River at Uttarkashi (Uttarakhand) India

Phytoplanktonic study is very important because they act as primary producers, food for variety of aquatic organisms and an efficient bio-indicator for water quality.Large population of phytoplankton is thriving in this wetland which enhances its productivity.A Total of 36 phytoplanktonic genera were identified in the present study.Bacillariophyceae include 15 genera, chlorophyceae include 10 genera, myxophyceae include 7 genera and desmidiaceae include 4 genera.In River Bhagirathi the overall total density fluctuates from 4.0 ± 1.41 Unit l -1 (October) to 179.0 ± 26.87 Unit l -1 (November).Seasonal total density ranged from minimum 77.67 ± 6.81 Unit l -1 (monsoon) at site S 1 to maximum 168.6 ± 53.29 Unit l -1 (winter) at site S 2 .