Ashtamudi wetland is an estuary, which lies in the Kollam district. This is the second largest wetland in Kerala with a palm shaped extensive water body and eight prominent arms, adjoining the Kollam town. All the arms converge into a single outlet at Neendakara near Kollam, to enter the Lakshadweep sea. This estuary is the deepest among all the estuaries of Kerala with a maximum depth of 6.4 m at the confluence zone. The Kallada river which originates from the western ghats, traverses through virgin forests and finally falls into the Ashtamudi wetland, after traveling a distance of about 120 km. It carries an average runoff of 76,000 million cu m of freshwater into the estuary every year. The wetland supports 57 species of birds (6 migratory and 51 resident species) and 97 species of fish (42 typically marine, 3 estuarine, 9 estuarine-riverine and 15 marine-estuarine). About 40 species of wetland dependant birds are noted in Ashtamudi Lake, out of which 45% are long distant migrants. The lake is the source of livelihood for the people living close to it in fishing, coconut husk retting for coir production and inland navigation services.The two most important factors causing deterioration of the wetland are pollution and encroachment. More and more industries including tourism coming up adjacent to the shores and basin are without effluent and waste treatment facilities. Coconut husk retting and related operations, though of small scale, are intensive, contributing heavily to the organic pollution load of the open water bodies. Wastes from the houseboats and resorts are also ultimately released into the wetland. The fishing boats fitted with outboard engines releases large quality of hydrocarbons into the system. The agricultural practices which involve the use of chemical/organic fertilizers and insecticides/pesticides, and the residues on entering the system cause pollution and eutrophication. The modern aquaculture also induces change in the ecosystem.The area of the lake decreased from original 54 sq m to 34 sq m in 2007. Land use changes and deforestation in the watershed as well as the increase in withdrawal of surface and ground water from the basin for irrigation, domestic, industrial and other uses have also put forth pressure on the system through stream flow changes. Hydrological interventions, like the Kallada Dam also exert pressure on the system. Many fish species may have become extinct due to lack of spawning facilities on the banks of the lake due to canalization of the lake?s banks by walls built of laterite and granite ston