Colimetric density assays of oyster harvesting areas in relation to environmental factors in Cananeia (SP)

The water in oysters harvesting areas of Cananeia Estuary was assessed by coliforms analysis throughout the 2005 to 2011 period. The thermotolerant coliforms presented geometric averages (18.80 NMP.100mL-1) within the limits allowed by CONAMA 357/2005, but it did not reach the minimum percentile established by the Resolution (80%). It was observed that there was a positive correlation between coliforms with rainfall factor and a negative one correlated with salinity factor. It was found also that the high tide showed lower density of coliforms and significantly differed from other upholstery analyzed. The analysis of the upholstery water showed variations in coliforms density and it is concluded that the concentration of coliforms in oyster production areas is directly influenced by salinity, rainfall and tidal range.

total coliforms; thermotolerant coliforms; water quality; Crassostrea sp