Chilika Lake is the largest brackish water lake with estuarine character that sprawls along the east coast of India. It is considered to be the largest lagoon in India and counted amongst the largest lagoons in the world. It is the largest wintering ground for migratory waterfowl found anywhere on the Indian sub-continent. It is one of the hotspot of biodiversity in the country, and some rare, vulnerable and endangered species listed in the IUCN Red List of threatened Animals inhabit the Lake area for atleast part of their life cycle. On account of its rich bio-diversity, Chilika lake was designated as a “Ramsar Site”, i.e. a wetland of International Importance. The Nalaban Island within the lake is notified as a Bird Sanctuary under Wildlife (Protection) Act, 1972. The National Wetlands, Mangroves and Coral Reefs Committee of the Ministry of Environment & Forests, Government of India, have also identified the lake as a priority site for conservation and management. The Lake is a highly productive ecosystem, with rich fishery resources. The rich fishing grounds sustain the livelihood of more than 0.2 million fisherfolk who live in and around the lake. It has a great heritage value and maritime trade to the far east countries used to take place from here.
It is also the largest wintering ground for migratory birds on the Indian sub-continent and supports some of the largest congregation of migratory birds from large parts of Asia, particularly during the winters that arrive from as far as the Caspian Sea, Lake Baikal, Aral Sea, remote parts of Russia, Kirghiz steppes of Mongolia, Central and South East Asia, Ladakh and the Himalayas to feed and breed in its fertile waters.