15-Changes of water quality parameters through ages in Chilika Lagoon & Its remediation

Abstract

The Chilika, located along Orissa Coast, is the largest brackish water Lagoon in Asia. As part of its protection and conservation measures, a new mouth was dredge opened at Sipakuda to facilitate free water exchange between the Lagoon and the sea in September 2000. The physico-chemical parameters such as Temperature. pH, Transparency, Dissolved Oxygen (DO) and Nutrients - Nitrate, Phosphate and Silicate were studied from Chilika Lagoon during June 2007 to May 2008 from four stations. The present study was made to know the impact of opening of new mouth at Sipakuda. The maximum temperature was 38.3oC during May 2008. The temperature ranged from 19.3oC to 38.3oC.The average salinity ranged from 7.3 to 26.7 ppt recorded from Kalupadaghat station and Alupatana station which are present at the Northern and Outer Channel Sector respectively. The maximum Secchi disc value was observed to be 1.92 meter in Central Sector. The pH ranged from 6.3 to 8.9.The Dissolved Oxygen value ranged from 6.2 mg/I to 7.8 mg/I from Pathara (Southern Sector) and Kalupadaghat (Northern Sector).The nutrient value showed distinct seasonal and spatial variation. Phosphate value was lower as compared to Nitrate. The physico-chemical parameters showed noticeable changes after opening of new mouth at Sipakuda.