Fecal coliform and e.coli contamination in cultured oyster, (Crassostrea iredalei), water and sediment of Setiu Lagoon, Terengganu

Abstract

This study is aimed to evaluate the level of fecal contamination that caused by sewage pollution in Setiu lagoon, Terengganu and also to determine whether the cultured oysters in the lagoon are safe for human consumption. Three sampling trips were conducted on 13th September 2006, lih October 2006 and 14th December 2006. Fourteen sampling stations were established in the lagoon. Total coliform, fecal coliform, Escherichia coli (E. coli) counts in water, sediment and cultured oysters (Crassostrea iredalei) were estimated by using Multiple Test Tube Fermentation of Standard Method. GAD test was carried out to determine the presence of E. coli in the samples. The mean of total coliform, fecal coliform and E. coli in waters of Setiu lagoon were 652.88 MPN.100 mL-1 , 219.46 MPN.100 mL-1 and 22.07 MPN.100 mL-1 respectively. The mean of total coliform, fecal coliform and E. coli in the sediments of Setiu lagoon were 3 7 .83 MPN.g·1 , 20.49 MPN.g"1 and 4.03 MPN.g"1 respectively. The mean of total coliform, fecal coliform and E. coli counts in cultured oysters were 176.93 MPN.g"1 , 245.52 MPN.g·1 and 1.72 MPN.g"1 respectively. The presence of total coliform, fecal coliform and E. coli in the waters and sediment of Setiu lagoon indicates that the lagoon has been contaminated by domestic sewage effluent. This study shows that, the level of fecal coliform is over the safety level for aquaculture but the E. coli in Setiu lagoon are still within the safety level for human consumption. Even then a proper measurement should be taken to maintain a healthy environment quality for future use.