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-binding molecular compounds in oysters transplanted from a low-contaminated area to a highly Cd-polluted site. These compounds have been compared to those found in oysters from the low-contaminated site, used as control, and from the 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 bound to soluble or insoluble compounds. The Cd distribution among cytosolic compounds was analyzed by gel permeation. Four classes of Cd-binding molecular compounds were separated and their relative significance in metal fixation was found to differ among resident and transplanted oysters.