Water Quality Indices and Plankton Diversity in Two Lakes of Mysuru City

The water quality index is a single number that expresses the quality of water by integrating the water quality variables. Its purpose is to provide a simple and concise method for expressing the water quality for different usage. The present work deals with the monitoring of variation of seasonal water quality index of some strategically selected surface water bodies. The index improves the comprehension of general water quality issues, communicates water quality status and illustrates the need for and the effectiveness of protective practices. The study deals with physico-chemical properties of Hebbal and Lingambudi lakes of Mysuru city and its impact on phytoplankton population. Several limnological parameters were evaluated during the period from December 2014 to July 2015 from four sampling stations sited along both lakes of Hebbal and Lingambudi. In order for the policy makers and general public to understand the extent of pollution in these lakes, water quality indices have been formulated. In this study, water quality indices which have been used are Canadian Council of Ministers of Environment (CCME) and National Sanitation Foundation (NSF). CCME provides information on quality for all designated purposes of a lake, while NSF provides the quality level, if the lake is being used, or is to be used for drinking purposes. The physical parameters included were temperature, turbidity and chemical parameters included were pH, temperature, dissolved oxygen, BOD, COD, nitrate, phosphate . A total 20 species were observed during the study period, maximum number of sp observed were in the Lingambudi lake i.e. 20 sp. There were 5 species observed from the class Chlorophyceae, 7 species of the class Cynophyceae, 8 of the class Bacillariophyceae,. The Microcystis species was observed in Lingambudi Lake indicates the signs of eutrophication of lake. The physico-chemical parameters such as nitrates, phosphate, temperature and TSS are favorable for the growth of phytoplankton. Maximum species of the class Bacillariophyceae were observed during study period.