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(012) Heavy metal contamination assessment in Sepetiba bay (Brasil) using the oyster Crassostrea rhizophorae. Rebelo, Mauro1, do Amaral, Maria Clara1, Pfeiffer, Wolfgang1, 1 ABSTRACT- Brazilian coast is very large and rich, nevertheless many aspects of its ecosystems, like susceptibility to contamination, remain to be cleared up. We used zinc and cadmium accumulation in different tissues of Crassostrea rhizophorae in an one year (98-99) survey to evaluate Sepetiba bay heavy metal contamination. Samples were dissected, ashed and digested with strong acids and metal concentrations were determined by atomic absorption spectrometry. Extremely high concentrations were found and pattern of tissue metal distribution suggests that whole body burdens are still the best compartment to analyze metal concentration. Lack of spatial distribution and temporal trends in metal concentrations suggests that waste disposal, harboring and dredging activities in the bay plays a more important role in metal contamination than seasonality or oyster physiology. Condition index determinations indicates that euthrophication due to domestic sludge disposal is a determinating factor in oysters development. Key words: oyster, heavy metal, spatial distribution, temporal trends |
