ASSESSMENT OF WATER QUALITY USING ENVIRONMENTAL VARIABLES AND DIATOM DIVERSITY IN VADDARAGUDI LAKE OF MYSURU DISTRICT, KARNATAKA, INDIA.

During the present investigation water quality analysis by environmental variables and diatom diversity were studied for a period of two years from January 2015 to December 2016. Samples were collected monthly in three different sites of lake and environmental variables such as pH, water temperature, electric conductance, Total dissolved solids, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total hardness, total alkalinity, carbon di-oxide, calcium and chloride etc. were examined along with the diatom diversity. During the study period, total 63 species of diatom were identified in which the most abundant taxa were Cocconeis placentula , Cyclotella meneghiniana , Nitzschia palea, Nitzschia frustulum and Fragilaria construens was found in large number followed by Achnanthidium minutissimum , Gomphonema sps. , Cymbella powainia , Cymbella bengalensis and Navicula sp. Diatom diversity observed more in summer followed by winter whereas least number of diatom were observed during monsoon. This study concluded that lake threatened ecologically due to various anthropogenic activities which lead to organic pollution and eutrophication status.