Cd distribution in the tissues of oysters (Crassostrea gigas) exposed chronically in situ

This study was designed to monitor the evolution of the nature of Cd-bindin g molecular compounds in oysters transplanted from a low-contaminated area to a highly Cd-polluted site. These compounds have been compared to those f ound in oysters from the low-contaminated site, used as control, and from t he native molluscs of the polluted area. We have also studied the influence of the length of exposure, collecting oysters after transplantation having been going on for 1 or 3 months. We have compared the quantities of Cd bou nd to soluble or insoluble compounds. The Cd distribution among cytosolic c ompounds was analyzed by gel permeation. Four classes of Cd-binding molecul ar compounds were separated and their relative significance in metal fixati on was found to differ among resident and transplanted oysters.