Studies on the hydrobiology of river cauvery and its tributaries arasalar from Kumbakonam Region (Tamilnadu, India) with reference to zooplankton.

The present investigation was an attempt to examine the composition, abundance, frequency of occurrence and diversity of net zooplankton species inhabiting in river Cauvery and its tributaries Arasalar at Kumbakonam, Tamil Nadu, India. From the selected 6 stations of river Cauvery and its tributaries Arasalar water samples were collected at monthly intervals. Qualitative and quantitative analysis of zooplankton were carried out during the year 2010 January to December. In the river Cauvery 45 species of zooplankton were identified. Rotifera species was dominant (34.97%); followed by Cladocera (29.92%), Copepoda (18.27%), Protozoa (12.2%) and Ostracoda (8.72%). Throughout the study, six species of Protozoa, 13 species of Rotifera, 12 species of Cladocera, 11 species of Copepoda and two species of Ostacoda were identified in the river Cauvery. Similarly, in the river Arasalar 38 species of zooplankton were identified. Rotifera species was dominant (37.87%); followed by Cladocera (26.32%), Copepoda (19.74%), Protozoa (9.17%) and Ostracoda (6.43%). During the study period, 5 species of Protozoa, 12 species of Rotifera, 11 species of Cladocera, 9 species of Copepoda and one species of Ostacoda were identified in the river Arasalar. During the winter and summer season maximum zooplankton diversity was recorded which was mainly dominated by Rotifer population. High turbidity observed as a major factor which restricts growth of the planktonic population during monsoon season. 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.

An assessment of water quality of river cauvery and its tributaries arasalar with reference to physico-chemical paremeters at Tanjore Dt, Tamilnadu, India.

Present work deals with an assessment of some physico chemical parameters of the water bodies of two rivers (Cauvery and Arasalar) which is suitable for human consumption have been carried out during the period of one year (January 2010 to December 2010). Analysis of some physico-chemical characteristics like air temperature, water temperature, transparency, electrical conductivity, total solids, total dissolved solids, total suspended solids, pH, free carbon dioxide, dissolved oxygen, BOD and COD has been done during the investigation period. BOD values were not compiling with WHO guide lines in the River Cauvery and total solids and BOD values were not compiling with WHO guide lines in the River Arasalar. Study indicates the rivers were slightly polluted by anthropogenic performance due to local anthropogenic activities, agricultural runoff and discharge of untreated municipal sewage, religious credence and subject to amend owed to seasons, climate and flows and influx of waters from various tributaries. In addition present study points out that the river Arasalar facing severe pollution followed by the river Cauvery.