Chapter 2 State-based fisheries management in Chilika Lagoon

Chilika Lagoon is the largest brackishwater lagoon in the Indian subcontinent, situated at latitude 19°28′ and 19°54′ north and longitude 85°05′ and 85°38′ east (Fig. 2.1). The lagoon extends from the southwest corner of Puri and Khurdra districts to the adjoining Ganjam district of Orissa state. The pear-shaped lagoon is around 64.3km long and its width varies from 18to 5km. It is connected to the sea through irregular water channels with several small sandy and usually ephemeral islands (CDA, 2008). The average lagoon area is 1,055km² which increases to 1,165km² during the rainy season and shrinks to 906km² during the summer season. Chilika Lagoon becomes less saline during the rainy season due to flood waters from 52 rivers and rivulets. It becomes more saline during the dry season as the supply of flood water is cut off when the south wind begins to blow and saline waters enter from the Bay of Bengal at high (Patro, 2001). The lagoon has three hydrologic subsystems (Mahanadi delta, western catchments, and the Bay of Bengal) influencing the hydrological regimes as shown in Fig. 2.1. The total inflow of freshwater from the Mahanadi delta has been estimated to be 4,912 million cubic meter, accounting for 80 percent of the total water flow. The maximum discharge of 3,182 million cubic meter comes from Makara River, followed by Bhargavi River (1,108 million cubic meter) and Luna River (428 million cubic meter) (CDA, 2008). Meanwhile, the western catchments account for 20 percent of the total fresh water flow.