Oysters (Crassostrea virginica) growing on wood treated with chromated copper arsenate (CCA) have elevated levels of metals, especially copper. Oysters living inside a residential canal lined with CCA wood bulkheads were often green and had high copper concentrations. These oysters had an elevated incidence of a previously described histopathological atrophic condition (metaplasia) of the digestive diverticula when compared to reference oysters collected from nearby rocks. The condition did not manifest itself, however, in oysters from the reference site there were transplanted into the canal for a three-month period. The authors cannot conclude that CCA wood exposure is responsible for the elevated incidence of the pathology in the canal oysters, however, since other sources of stress exist in that environment.