A Comparative Study of Heavy Metal Accumulation in Tissues of the Crested Tern, Sterna Bergii. Breeding Near an Industrial Port Before and After Harbour Dredging and Ocean Dumping.

Abstract

Eight different tissues taken from crested terns, Sterna bergii, were analysed for the metals cadmium, lead, copper, chromium, manganese, zinc and iron. Birds were taken from a breeding colony before and after the commencement of harbour dredging and ocean dumping operations in nearby Port Kembla Harbour. Levels of chromium and lead were similar in both adult and fledgling terns after dredging began, indicating that chicks acquired these metals from food brought to them by adult birds. However, these metals were found in relatively low concentrations. No conclusive evidence was found of increased assimilation of heavy metals into the trophic structure of communities in waters adjacent to the Five Islands after dredging and ocean dumping operations.