Phytoplankton diversity in response to abiotic factors along Orissa coast, Bay of Bengal

The qualitative and quantitative distribution of phytoplankton with regional variation in the coastal waters of Orissa coast were presented out of the pooled data of eight stations sampled during summer season of 2008–09 and 2009–10. Significant spatial variations in temperature, pH, salinity, dissolved oxygen, biochemical oxygen demand, nitrites, nitrates, ammonia, phosphate, silicate were monitored during the study. Total ninety five species of phytoplankton were recorded belonging to Bacillariophyceae, Dinophyceae, Cyanophyceae, Haptophyceae group. Phytoplankton density ranged from approximately 8460-50720 nos./l and showed complete dominance of diatom genera (Bacillariophyceae) in both the year in all stations. The concentration of chlorophyll-a ranged from 0.45 to 7.6 mg/m³. Statistical analysis predicted that the phytoplankton population was positively related to the chlorophyll-a concentration and nutrients. The present study indicates that the phytoplankton population, diversity and species composition fluctuate significantly in relation to the various physico-chemical parameters.