Greening and Copper Accumulation in the American Oyster, Crassostrea virginica, in the Vicinity of a Steam Electric Generating Station

Abstract

The effects of heated effluent on oysters in the Patuxent River were investigated. Oyster meats near the outfall of a steam electric generating station started to display green color shortly after initiation of plant operation. In time, the affliction increased in intensity and spread to oyster stations farther removed from the outfall. The greening of Patuxent oysters was probably caused by copper uptake, since green color and copper concentration (mg of copper per g dried meat weight) were closely correlated. Copper content of oysters decreased with distance from the outfall. There was an inverse relationship between oyster condition and copper concentration. This was most evident at stations near the outfall where oysters had high copper content. Amounts of copper per oyster, based on mg of copper per liter shell cavity volume, did not display great seasonal fluctuation. Oysters at special stations, established to investigate a possible copper source upstream from the plant, showed a reduction in mg of copper per g dried meat, while oysters at stations inside and near the outfall increased sharply in mg of copper per g dried meat. Indications in the Patuxent point to a relationship between oyster copper uptake and power plant operation.