STUDIES OF SEASONAL VARIATIONS IN PHYTOPLANKTON DENSITY OF A SMALL HIMALAYAN HILL STREAM BACHCHAN GAD

In the present study phytoplankton density and physico- chemical parameters were studied in Bachchan Gad. A total of 30 genera of phytoplankton belonging to the families Chlorophyceae(8 genera), Bacillariophyceae (19 genera) and Cyanophyceae (3 genera) were recorded during the present investigation. Regular sampling for the physico-chemical parameters were confined to temperature (air and water), mean velocity, mean depth, mean width, dissolved oxygen and pH. Overall variation recorded in phytoplankton density, due to change in physico-chemical nature, variation in altitude and longitude channel course, substratum and geometry of the stream.