Water is very important resource for every living organism of the world. It is available through many sources to all. Some of its sources are rivers, ponds, rain and lakes etc. Water fulfills the daily needs of every living organism. It also has some biological importance. Its role in metabolic activities is significant. Lakes are good sources of water. Lakes are used as tourist places for human beings and works as money earning service for the local people by providing the facilities of boating and fishing. Another big benefit of lakes is that it preserves many living organisms like fishes, ducks, small intersects to maintain the balance of ecology. Many species of fishes are found in lakes. Hence, lakes are very much valuable in preserving these organisms. The current article highlights the ecology of lakes and its conservation.