Seasonal Variation of Phytoplankton from Parangipettai Coastal Waters, Bay of Bengal, Tamil Nadu, Southeast Coast of India

The study of phytoplankton distribution and its seasonal variation was carried out during theApril 2014 to March 2015, from the Parangipettai coastal waters, Bay of Bengal, TamilNadu, and south-east coast of India. Various physic-chemical parameters were analysed andthe correlation with phytoplankton population density was established using Pearsoncorrelation co-efficient. This result showed that the phytoplankton population density waspositively correlated with atmospheric temperature, surface water temperature, salinity, pH,chlorophyll „a‟ primary production (p<0.01) where negatively correlated with rainfall andnutrients (p<0.5) were detected. Totally 119 species of phytoplankton were recorded whichincludes 81 species of Bacillariophyceae (Diatoms), 24 species of Dinophyceae(Dinoflagellates), 6 species of Cyanophyceae (Blue-green algae), 7 species of Chlorophyceae(Green algae) and one species of Silicoflagellates (Chrysophyceae) during the study period.Bacillariophyceae species was the dominant followed by Dinophyceae, Chlorophyceae,Cyanophyceae and Silicoflagellates. The lowest phytoplankton diversity in the monsoonperiod and highest diversity in the post monsoon period was recorded. The Parangipettaicoastal waters have been found to be very rich in phytoplankton diversity.Keywords: Phytoplankton, Seasonal variation, Primary production, Nutrients, Bay of Bengal,Hydrological parameters