~ 265 ~ International Journal of Fisheries and Aquatic Studies 2017; 5(1): 265-267 E-ISSN: 2347-5129 P-ISSN: 2394-0506 (ICV-Poland) Impact Value: 5.62 (GIF) Impact Factor: 0.549 IJFAS 2017; 5(1): 265-267 © 2017 IJFAS www.fisheriesjournal.com Received: 09-11-2016 Accepted: 10-12-2016 Archana Gupte Department of Botany K.M.E. Society’s G.M. Momin Women’s College, Bhiwandi, Maharashtra, India Correspondence Archana Gupte Department of Botany K.M.E. Society’s G.M. Momin Women’s College, Bhiwandi, Maharashtra, India Diversification in phytoplankton population of Shelar Lake Archana Gupte Abstract Thane district consists of many fresh water bodies. One of them is Shelar lake, situated in the rural area of it. Three stations having environmentally different conditions such as cow shed near one station and oil runoff from nearby highway into another station were selected for the study. Phytoplankton study was carried out in a lake for a period of one year i.e. from October 2010 to September 2011.Total 19 genera were recorded belonging to chlorophyceae, cyanophyceae and bacillariophyceae. Extensive growth of phytoplankton, caused by increased amount of nutrients is a common problem in lakes. The lake shows slight eutrophication in the pre monsoon period which reduces the clarity of water and has depletion of oxygen content. It was observed during the study that some of the members of chlorophyceae, bacillariophyceae and cyanophyceae show their appearance only during premonsoon. Phytoplankton responds rapidly to the condition changes. Conditional changes result in the formation of high compositional diversity. Phytoplankton like Navicula, Nostoc, Microcystis, make their appearance in large quantity during premonsoon indicating the lake is polluted. Phytoplankton belonging to Chlorophyceae group shows domination on cyanophyceae and bacillariophyceae group. Keywords: Phytoplankton, Shelar, premonsoon, fresh water 1. Introduction Phytoplanktons are small organisms that drift on water currents. They are microscopic aquatic plants, occurring as unicellular, colonial or filamentous forms, without any resistance to currents, and are free floated or suspended in open/pelagic waters. Phytoplankton communities are widely spread from aquatic to terrestrial lands. Plankton forms the first ring of food chain in aquatic environment affecting the efficiency of this environment. Phytoplankton composition is a tropic indication of the water mass. In addition, phytoplankton species are used as an indicator for determining the nutrient level which is the basis for preparing and monitoring the strategies of the lake management in the lakes. Plankton is the major primary producers in many aquatic systems and is important food source for other organisms [3] . The abundance of phytoplankton in aquatic ecosystems is primarily controlled by the availability of the nutrients nitrogen and phosphorus in the water column and in sediments, although light and temperature also plays an important roles in determining the distribution and abundance of these organisms. In tropical lakes conspicuous temporal fluctuation in rainfall, runoff and vertical mixing imply some annual variation patterns which are reflected on species composition and abundance of phytoplankton [10] . The first and foremost visible symptoms of nutrient enrichment are the prolific growth of algal communities which produce blooms. The Shelar Lake is a fresh water body situated in the rural area of Thane district near Bhiwandi. Geographically it lies between 18 0 42’and 20 0 20’ North latitude and 72 0 45’and 73 0 45’ East longitude. At one end the lake have entry of national highway run off during rainy season while at the other end entry of agricultural runoff make the water polluted. Presence of cow shed at the edge of Lake made the water rich in nitrogenous waste. Phytoplankton responds very quickly to environmental changes because of their very short life cycle and hence their standing crop and species composition are likely to indicate the exact quality of a water body in which they are found. The distribution, composition and succession of plankton give valuable clue for determining the environmental conditions, which determine their abundance is fundamental to any scientific utilization of water resources. The present study has been undertaken for the first time on the Shelar lake to study the effect of climatic change on the phytoplankton composition.