Some Planktonic Diversity of River Gandak & Its Relation to Primary Productivity

Abstract

The primary productivity of any aquatic ecosystem depends on the plank tonic bio diversity. Plankton is starting point of energy transfer in the aquatic ecosystem and their well –being is of paramount importance to the over all health and integrity of the system. Qualitative and quantitative analysis of different groups of organism lead to the establishment of bio – indicator, indices and systems which can be assess the pollution and tropic status of water bodies. The present study was aimed to find out the impact of higher population on the plankton population of the Gandak river. Plankton samples were collected from Hajipur [New pool ghat 100 mit far away] sites during the study period [Oct. 2016 – Sep. 2017] for three seasonal variation winter, summer and rainy season. Plank tonic diversity in presence of phytoplankton is higher 248 ±19.82 in winter season and lower 11.64 ± 14.26 in rainy season and Zooplankton is higher 51.78 [Rotifera] in winter season and lower is 18.29 [crustacean]in rainy season. Studies revealed that phyto plankton population was dominated by members of Chlorophyceae, Bacillariophyceae, and Cynophyceae and Zooplankton population was dominated by Rotifer, Crustacea and Protozoan. The present study was to assess the status of phytoplankton diversity and biomass in order to know the productivity of Gandak River. A total 29 species, 13 chlorophyceae, 7 Bacillariophycea and 9 Cyanophyceae and in Zooplankton total 5 species of Rotifera, 4 species of Crustacea and 7 species of Protozoa is maximum to minimum were observed.