Chilika has the distinction of being the largest brackish water wetland in India and is situated in the east coast of the state in the districts of Puri, Ganjam, and Khurda. The quaint lagoon is famous for its magnificent biodiversity including the migratory birds and has been declared as a ‘Ramsar Site’. Chilika Lake is studded with tiny mindboggling islands and sandy beaches interspersed with casuarina grooves along the Bay of Bengal. The resident and migratory birds that flock along the lake during winter include flamingo, white bellied sea eagle, spot billed pelican, heron, egret, avocet, wigeon, spoon bill, gull, tern, kingfisher, etc. The endangered Irrawady Dolphins find their abode in Chilika and are a treat to watch. The sunrise and sunset scenes from Chilika are an ever memorable experience.Chilika lagoon has been designated as a Ramsar site (Wetland of International importance) from the 1st October, l981. The Chilika Lagoon is hot spot of rich Biodiversity.The water spread of the lagoon varies between 1165 Sq.km in monsoon to 906 Sq.km during summer, and extends over Puri, Khurda and Ganjam districts.
There are 546 species of angiospermic plants belonging to 379 genera and 107 families, above 100 phytoplankton genera, 20 species of weed and 7 pteridophytic species documented so far in the Lagoon and the islands.Birds belonging to over 230 species including 14 birds of prey (32% aquatic, 22%waders,
and 46% terrestrial birds) are seen in this lake, of which 95 species are intercontinental and local migrants.
The other vertebrate fauna includes:
· 321 species of fish and crab (fresh water, estuarine and marine species),
· 7 species of amphibians,
· 30 species of reptiles (12 species of lizards and 18 species of snakes) and
· 18 species of mammals.
Two major crabs species (Scylla serreta and Neptunus pelagicus), available in Chilika are of commercial importance.
At present there are about 80-90 Irrawaddy dolphins in the entire lake. A small population of Bottle nosed dolphin, Sousa chinensis also migrate in to the lagoon from the sea Numerous islands are present in the lagoon, prominent among which are Kalijai, Honeymoon, Barakuda, Breakfast, Birds Island, etc.