ALGAL SPECIES DIVERSITY AND PALMER POLLUTION INDEX OF PUTTENAHALLI LAKE IN BENGALURU, INDIA

In this Anthropocene period, due to high human interference for the developments in the fields of agriculture, industryand urban events, especially around lake water systems have affected significant changes in quality and quantity of theresources and enriched water with mineral nutrients, such as nitrogen and phosphorus as a consequence, lakes gotenriched with increased algal productivity which in turn has led to oxygen depletion, recreational impairment,biodiversity loss and resulted in deterioration of habitat quality. The present study attempts to assess the water quality ofPuttenahalli lake through phytoplankton studies. The Puttenahalli lake has been hysterically polluted by sewage dischargefrom two places, one from the underground drain in Nataraja layout and the other from an unknown source in thesouthern side which has led to a massive fish kill and organic load in the lake. The phytoplankton studies revealed thepresence of harmful algal blooms like Spirogyra sp., Mycrocystis sp., Cylindrospermopsis sp., Arcella sp., Anabena sp.,Scenedesmus sp., Ulothrix sp., Ankistrodesmus sp., Cosmarium sp., Trachelomonas sp., Zygnema sp., Navicula sp., Synedra sp.,Cymbella sp., Nitzschia sp., Cyclotella sp., Selenastrum sp., diatoms sp., and many other cyanohabs were abundantly presentin the studied lake. These Cyanobacterial blooms are currently a great threat to the ecological integrity and sustainabilityof lake water resources.