Heavy metal depuration in flat tree oysters Isognomon alatus under field and laboratory conditions

Oysters Isognomon alatus containing high concentrations of Zn, Cu, Pb and Cd were collected from the Sepang Besar River, and transferred to the Sepang Kecil River where the native oysters contain low metal concentrations. Concentrations of heavy metals in oysters were measured monthly over six months. The concentrations of all metals decreased significantly (p Pb > Cu > Zn. A comparison between laboratory and field data showed that depuration of metals under the laboratory conditions is significantly faster than in the field