Vembanad estuary

Phytoplankton plays an important role in primary organic production in the estuaries and also a source of biologically active components. In order to evaluate the phytoplankton diversity an investigation of eight stations representing central to southern end of Vembanad estuary was conducted. Studies were carried out during the pre-monsoon and monsoon seasons of 2019.In the present study, a total 42 species of phytoplankton were recorded, among which 18 genera and 28 species belongs to Bacillariophyceae, 7 genera and 9 species to Chlorophyceae, 2 genera and 3 species to Cyanophyceae, and 2 genera to Euglenophyceae. Bacillariophyceae formed the dominant group in both the seasons. Palmer’s algal general pollution index is employed in all the sampling stations. Station S6 (Vayalaar) was found to be with high organic pollution in both pre-monsoon and monsoon with index value of 22 and 21 respectively. From the present study the Palmer's algal pollution index value represent probable high organic pollution in Vembanad estuarine system. The agricultural fertilizers from the Kuttanad rice fields, solid wastes and sewage wastes might be the major source of pollution in Vembanad estuary. Economically important and nutraceutically valuable members like Chlorella vulgaris, Scenedesus sp, Oscillatoria sp and Euglena sp were identified during the study period.