Heavy metal speciation in waters, sediments and biota from Lake Macquarie, New South Wales

Abstract

The distribution and bioavailability of heavy metals in waters and sediments from Lake Macquarie (N.S.W.) have been examined. Elevated concentrations of zinc, lead, cadmium and copper detected in surface sediments and waters from the northern end of the lake are attributable to discharges from a lead-zinc smelter on Cockle Creek. The majority of the metals are in bioavailable forms and are shown to be accumulated in seagrasses, seaweeds and bivalves. Calculations indicate that, at the current rates of discharge, the concentrations of bioavailable metals in newly-deposited sediments should not be deleterious. Elutriate tests showed that there will be no significant mobilization of metals during dredging operations to remove the contaminated sediments.