Spatial and seasonal variations of phytoplankton species and their relationship to physicochemical variables in the Cochin estuarine waters, Southwest coast of India

943-953During the present study total 120 species of phytoplankton were identified and which represents different distinct classes viz: Bacillariophyceae (65), Dinophyceae (21), Chlorophyceae (25), Cyanophyceae (6), Chrysophyceae (1), Dictyophyceae (1) and Zygnematophyceae (1). Diatom formed the most dominant group. The average number of total phytoplankton density varied from 484600 cells L-1 to 678600 cells L-1. Maximum density was found during post monsoon season coinciding with the stable hydrographical conditions. Change in phytoplankton density and species diversity in different seasons was found to be significant by varying water characteristics