Letty Titus and B.T. Sulekha
Abstract
The study investigates the bioaccumulation of E. coli in Indian backwater oyster (Crassostrea madrasensis) in Ashtamudi Estuary, a Ramsar site in Keralain light of increasing urban pollution. Total heterotrophic bacteria and E. coli in water, sediment and edible bivalve species from six sites are seasonally analysed. The results show more bacterial accumulation during monsoon especially in oysters. Temporal variation of TPC is observed in water and sediment. Pearsonââ¬â¢s correlation revealed significant positive correlation of TPC in water with that of sediment. Positive correlation of TPC with E. coli in all the media and E. coli in different media indicates the effect of incoming waters having heterotrophic bacterial load. Study shows that in some regions the E. coli counts in oyster are higher during monsoon. The BAF also showed a general increase during monsoon and generally exceeded the European standards for Class A waters. It requires special care to improve the environmental stability of the estuary.