Context: As per the water bird status survey-2022 conducted in the Chilika lake, nearly 11 lakhs water bird and wetland dependent species visited the lake.

Key Points

• The census was undertaken jointly by the Odisha State Wildlife Organisation, the Chilika Development Authority (CDA) and the Bombay Natural History Society. 
• The Chilika Lagoon was divided strategically into 21 segments for the census.
• A total of 10,74,173 birds of the 107 waterbird species and 37,953 individuals of 76 wetland-dependent species were counted at the entire lagoon.
• Last year, the count in Chilika was over 12 lakh. Bird census members reported rare sightings of the uncommon Mongolian gull.

About Chilika Lake

• It is Asia’s largest and world’s second-largest brackish water lagoon after The New Caledonian barrier reef.
• A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses.

Process of Formation

• It might have begun in the latter part of the Pleistocene epoch, around 20,000 years ago.
• India’s peninsular river Mahanadi carried a heavy load of silt and dumped part of it at its delta.
• As the sediment-laden river met the Bay of Bengal, sand bars were formed near its mouth.
• These created a backflow of the seawater into the sluggish fresh water at the estuary, resulting in the huge brackish water lake.

Physical Features

• Chilika is 64 kilometres long in the north-south direction and 13.5 km wide in the east-west direction.
• It is spread over the Puri, Khurda and Ganjam districts of Odisha.
• It is located at the mouth of the Daya River, flowing into the Bay of Bengal, covering an area of over 1,100 km2.

Biodiversity 

• Chilika lake hosts birds migrating from thousands of miles away from the Caspian Sea, Lake Baikal, Aral Sea, remote parts of Russia, Kirghiz steppes of Mongolia, Central and South-East Asia, Ladakh and the Himalayas. 
• The winged guests find the vast mud-field and abundant fish stock here suitable to congregate.
• It is the largest wintering ground for migratory birds on the Indian sub-continent and is home to a number of threatened species of plants and animals.

Major attraction 

• Irrawaddy dolphins are often spotted off Satapada Island.
• Kalijai Temple – Located on an island in Chilika Lake.
• Nalabana Island (Forest of Reeds) covering about 16 sq km in the lagoon area was declared a bird sanctuary in 1987.

International Recognition 

• It has been listed as Ramsar Site as well as a tentative UNESCO World Heritage site.
• In 1981, Chilika Lake has designated the first Indian wetland of international importance under the Ramsar Convention.