East Kolkata wetlands is a complex natural and human made wetlands lying east of Kolkata, covers 125 sq. km. of area which include salt marshes, salt meadows, as well as sewage farms and settling ponds. It is the largest sewage fed aquaculture of the world. It is designated a “Wetlands of International Importance” under Ramsar convention on 19th August 2002. The Ramsar Convention describes EKW as one of the rare examples of environmental protection and development management” where city’s sewage is treated through a network of canals and fishponds, more over, it is the ground of waste water pisciculture. This system is so effective that Kolkata was not provided funds for setting up conventional sewage treatment plant under the Ganga Action Plan. Now, a part of EKW is used by Kolkata Municipal Corporation as a dumping ground of solid-waste. The problem is that the wetlands are shrinking because of various reasons, such as- rapid urbanization, excessive silting, human habitation etc. The results are obvious- pollution, loss of biodiversity. In this present paper the focus will be on the reasons for the shrinkage of East Kolkata Wetlands and the effect on biodiversity loss and most importantly the possible suggestions to overcome this problem.