Diatoms as water quality indicators in the Cauvery River, South India

River is the most important natural resources for human life. A river is defined as a large natural stream of water emptying into an ocean and lake. Moving water dilutes and decomposes pollutants more rapidly than standing water, but many rivers and streams are significantly polluted all around the world and also human use including household, industrial, agricultural and recreational activities affects water quality. In recent years, the pollution status of aquatic system is prepared by using diatom. Diatoms are the main producers in rivers and it can be easily collected and preserved. Diatoms based indices are important tools for assessment of environmental conditions in all aquatic systems. Objectives of this research are to determine the pollution status and environmental impact assessment (EIA) of the River by using diatoms. Our work was focused on diatom indices and water quality index of the Cauvery River, Tamil Nadu, South India.