Chilika , the largest brackish water lagoon with estuarine character, situated along the east coast of India in the state of Orissa. Chilika is spread over three district namely Puri, Khurda and Ganjam of costal Orissa. Chilika shelters some of the rare, vulnerable and endangered life-form listed in the IUCN Red List of threatened species. Chilika is not only home to numerous aquatic fish, plant and animals but also supports some of the largest congregation of migratory birds in the country. Due to its rich bio-diversity, Chilika was designated as a "Ramsar Site".

Chilika, second largest lagoon of the world covers an area of 1165 to 906 Sq. Km. during monsoon and summer respectively. Some of the islands in the lagoon are nesting site for various bird species. Such few islands are Krushnaprasad, Nalaban, Kalijai, Somolo, Honeymoon, Breakfast and Birds Island. The Nalaban Island covering an area of 15.53 Sq. Km. has also been declared as Bird Sanctuary in the year 1973 .52 river and rivulets pour freshwater into the lagoon and thus balance of fresh and salt water maintained, which is most important element for the survival of the species found in the lagoon area. A 32 km long, narrow channel connects the main lagoon to the Bay of Bengal.

Chilika is one of the the largest wintering ground for migratory birds in the country and a bio-diversity hotspot. Flocks of migratory birds arrive from Russia, Kirghiz steppes of Mongolia, Central and Southeast Asia to feed and bread in its fertile water. Chilika also famous for sheltering some of the endangered aquatic mammals swims in the eastern cost of India.

Flora and Fauna

Total 710 species of plants identified from the water bodies, islands and shoreline of Chilika. This lagoon is very rich with aquatic plant life including Phytoplankton and algal communities. 5 species of sea grasses, Marine seaweeds, fishes and crabs are found in the brackish water of Chilika Lagoon.

Almost 260 species of fish have been recorded from the lagoon area including threatened species like Milk Fish (Seba Khainga), Indo-Pacific Tarpon ( Panialehio), Ten pounder (Nahama), Bream (Kala Khuanti) and Mullet (Kekenda). 28 species of prawns and 34 species of Crabs found here is the example of rich bio-diversity of the area. Presence of ample fish, shell fish and crab species supports a very unique marine life. More than 100 species of mammals recoded from the Chilika area. The Irrawaddy Dolphin is the flagship species of Chilika lagoon. This particular dolphin is only found in some restricted area of India. It is classified as Critically Endangered in the IUCN Red List. Bottlenose dolphins sometimes also migrate from the sea in to the lagoon.

About 205 species of birds have been recorded from the area with some of the rare and threatened species . Large flocks of Greater Flamingo arrive here every year for wintering. Other waders reside or migrate here includes Lesser Flamingos, Goliath Heron, Spoonbill, Purple Heron, Little ringed plover, Collared Pratincole, Ruff, Dunlin, Snipes, Avocets, Godwit etc. Some of the rare birds recorded from the area are Asiatic Dowitchers, Dalmatian Pelican, Spot-billed Pelican and rare migrant Spoon-billed Sandpiper. Compact flocks of Brahminy Duck, Shovellers, Northern Pintails, Gadwall, Mallard, Pochards and Lesser whistling Teal also seen around the lagoon. Chilika houses good number of raptor species which indicates the stable and flourishing eco-system of the area. Raptor found here includes Brahmini Kite, Osprey, White-bellied Sea Eagle, Pallas’s Fish Eagle, Marsh Harrier and Peregrine Falcon. In January 2008, a bird census involving wildlife officials counted 900,000 birds in Chilika Lagoon area, out of which 450,000 were sighted alone in Nalaban Island.