Fisheries Enhancement after Hydrological Intervention in Chilika Lagoon and Strategies for Responsible Management

Abstract

Chilika lagoon situated in the state of Orissa on the east coast of India is a hotspot of aquatic biodiversity including fish germplasms. Fishery yield from the lagoon contributes 71% to the total economic valuation of the ecosystem. The ecosystem suffered rapid degradation during the last few decades due to anthropogenic pressure and natural changes. Fish yield from mid-eighties onwards until hydrological intervention made by Chilika Development Authority during September, 2000 showed declining trend, registering lowest ever landings of 1274 t during 1995-96 and 1746 t in 1999-2000, immediately before opening of the new lagoon mouth. The opening of artificial mouth by dredging the sand spit reduced the 1ength of outer channel by 18 km. The hydrological intervention has resulted in many positive impacts such as spectacular increase in fishery yield and biodiversity, improvement in overall salinity regime, natural eradication of freshwater weeds, flushing out of silt etc. Sudden increase in fishery yield during 2000-01 immediately after opening of the new mouth registered 185.42% increase over the pre-mouth base year (1999-2000) and an all time high yield of 11,988.88 t during 2001-02, showing 586.74% increase over the base year has been recorded whose economic valuation was estimated at Rs.571.6 million. The average fishery yield for three years (2000-01 to 2002-03), economic valuation of fish catch, fishery diversity, migratory fish component, commercial fish groups, average productivity, per capita income and catch per unit effort (CPUE) during the post-mouth period registered 432.06%, 621.47%, 19.85%, 7.20%, 42.86%, 482.59%, 373.15% and 432.27% increase, respectively over the base year, 1999-2000.