Water Quality of Gubbi Tank, Tumkur in Relation to Physico-chemical Characteristics, Diversity and Periodicity of PhytoplanktonMuralidhar V.N., Narayana J., Puttaiah E.T. and Laksmi Narayana*
Department of PG Studies and Research in Environmental Science, 
Kuvempu University, Jnanasahyadri – 577451, Shimoga, Karnataka, India
* Karnataka State Pollution Control Board, Bangalore. Karnataka, India


The paper describes the physico-chemical characteristics of water, diversity and periodicity of phytoplanktons. Surface water samples were collected at an interval of 30 days for a period of one year using plastic cans of three litre capacity. Standard procedures were followed during collection, preservation and analysis of water samples for various physico-chemical and biological parameters. The physico-chemical parameters studied were within permissible limits. The phytoplanktonic community is represented by five classes and seventy two species. Density of different groups of phytoplankton is more in summer season than during rainy and winter seasons. Based on the results of Nygaard’s and Palmer’s algal indices, it has been deduced that the tank is oligotrophic. Due to the increased domestic activities and inflow of sewage, the tank is tending to become eutrophic. Strategies for the conservation of the tank are discussed.