Seasonal Concentration of Coliform Bacteria by Crassostrea virginica , the Eastern Oyster, in Chesapeake Bay.

Samples of water, sediment and oysters from actively harvested oyster beds located in Tolly Point and Eastern Bay of the Chesapeake Bay region were sampled over a 2-year period during which total coliforms remained at low densities. Under these conditions, there were times when total coliform densities in oysters significantly varied from those in overlying waters. The observed seasonal concentration of coliforms by oysters should be considered when assessing the efficacy of bacteriological quality standards.