Background Lake Chilika
Lake Chilika is the largest brackish water lagoon in Asia and the second largest coastal lagoon in the world. The lagoon is located on the east coast of India, at the mouth of the Daya River, which flows into the Bay of Bengal and covers an area of 1,100 km². Its width varies between 5 and 18 km, its length is 64.5 km. A total of 52 tributaries feed the lake with water from the catchment area.
Due to its rich biological diversity, Lake Chilika was the first Indian wetland of international importance to be designated under the Ramsar Convention in 1981. The brackish water lake is separated from the Bay of Bengal by a 60 kilometer long, narrow strip of sand and swampy islands. The unusual hydrological diversity gives Lake Chilika the characteristics of a lake, estuary and lagoon. The gradual transition from freshwater to saltwater leads to the coexistence of four different ecosystems and the development of a unique biodiversity for lakes. The four ecosystems differ in depth and salinity: southern zone (high salinity), central zone (maximum depth 3.7 m), northern zone (depth less than 50 cm) and outer channel (depth 20 cm).
Lake Chilika is also the largest wintering area on the Indian subcontinent, with 225 bird species at weddings. Migratory birds come from the Caspian Sea, Lake Baikal, the Aral Sea, from Central and Southeast Asia.
The Chilika Lagoon with its rich fishery resources secures the livelihood of approximately 200,000 fishermen, who live around Lake Chilika. The lake is home to 317 species of fish, including both freshwater and saltwater fish. Cashew nuts and rice are the main crops grown on agricultural land. Pesticides and fertilizers from the cultivated areas around the lake impair water quality. On the west side of the lake, there are forest areas, the use and deforestation of which leads to sediment inputs into the lake.