Distribution, composition and seasonal abundance of phytoplankton community in Lake Naukuchiyatal, Uttarakhand, India

Forty seven taxa of phytoplankton belonging to 6 taxonomic groups were collected from the lake during two years of the study. Synedra ulna, Synedra sp., Peridinium sp., Microcystis aeruginosa, Navicula sp., Amphora ovalis, Tabellaria fenestrata, Chlorococcum humicola, Ankistrodesmus falcatus were important with regard to their frequency of occurrence. Based on two years mean, community abundance of phytoplankton was 5.5×10⁵cells/l. The group Bacillariophyceae was the most dominant group followed by Cyanophyceae and Chlorophyceae in terms of number. The two years average gross primary production (across months and depths) was 213 g C/m²/y while the community respiration was113 g C/m²/y. The Shannon-Wiener diversity index ranged from 1.16 to 3.48 while the concentration of dominance varied from 0.03 to 0.61.