Temporal and spatial variability in Zn, Cr, Cd and Fe concentrations in oyster tissues(crassostrea brasiliana lamarck, 1819)from Sepetiba Bay, Brazil

Abstract
Temporal and spatial variability in metal concentrations (Zn, Cr, Cd and Fe) in soft tissues of the oyster C. brasiliana from Sepetiba Bay and Ribeira Bay were determined for three different periods.Significant spacial differences were observed for Zn and Cd but no temporal variations were detected. High correlation factors between Zn and Cd were found as well. The oyster C. brasiliana proved to be a good ecological indicator for Zn and Cd monitoring programs.