Studies on the Hydrobiology of River Cauvery and Its Tributaries Arasalar from Kumbakonam Region (tamilnadu, India) with Reference to Phytoplankton

The present investigation was an attempt to examine the composition, abundance, frequency of occurrence and diversity of net phytoplankton species inhabiting in river Cauvery and its tributaries river Arasalar at Kumbakonam area (10.110-12.70 E latitude and 78.86-79.85 N longitude), Tamil Nadu, India. From the selected 6 stations of river Cauvery and river Arasalar water samples were collected at monthly intervals. Qualitative and quantitative analyses of phytoplankton were carried out during the year 2010 January to 2011 January. In river Cauvery about 68 species of phytoplankton were found comprising Chlorophyceae 33.82%, Bacilleriophyceae 27.94%, Cyanophyceae 32.35% and Euglenophyceae 5.88%. Similarly in river Arasalar about 63 species of phytoplankton were found comprising Cyanophyceae 34.92%, Bacilleriophyceae 28.57%, Chlorophyceae 31.74% and Euglenophyceae 4.76%. Not all of the identified species were found in all six sites, thus indicating different types of pollution across the sites. There was no significant difference in the quantity of phytoplankton across the sites; however the quality differs as a result of the various stressors. These findings indicate that the effect of anthropogenic stressors, brewery effluent and refuse impact the water body, albeit minimally . This study will aid the baseline data for aqua-culturists in nearby regions.