Bangalore has many man-made wetlands, that were artificially built for various hydrological purposes and mainly to serve the needs of irrigated agriculture. The number of man made lakes has fallen from 262 in 1960, to some 81 lakes at present (Lakshman Rao, N. et al 1986). The quality of water has reduced due to discharge of industrial effluent and domestic sewage ( Shivshanker, T.V. et al, 1985). Many lakes have been lost by converting wetlands for residential, agricultural and industrial purposes ( Venkataraman R.,1997). More than 28 % of lakes suffered from various degree of eutrophication and nearly 30% of vegetables were grown in untreated water(Krishna, M.B. et.al).Earlier investigations also revealed that,for nearly 40% of the lakes, sewage was the main source, 13% lakes surrounded by slums and loss of catchment for nearly 35% lakes surveyed between 1973 and 1996 (Deepa,R.S, et.al,1996).Now it has become necessary to preserve and conserve these vanishing ecosystems, which is important for various purposes and to achieve ecological sustainability.