Trace metal contamination of shallow marine sediments near a lead smelter, Spencer Gulf, South Australia

Abstract

The surface (< 10 cm) marine sediments of Spencer Gulf, a hypersaline seagrassed embayment, near Port Pirie, South Australia; were examined for concentrations of Ca, Cd, Cu, Mg. Mn, Ni, Pb, Zn, total organic carbon, clay, silt, sand. shell, and 'undissolved fraction' (resistant plant debris).

Elevated concentrations of Pb, Cu. Zn, Mn and Cd were found in sediments adjacent to the liquid effluent discharge from a lead smelter. Outside the immediate discharge area the concentrations of Cu and Mn rapidly approached background levels where their concentrations were correlated to those of non- contaminant sediment parameters. The highest concentrations of Cd were found further from the source of effluent than those of the other four contaminant metals (Cu, Mn, Pb: Zn), and decreased to undetectable levels at the furthest sites. Pb and Zn also occurred at background concentrations at sites away from the effluent discharge. but no correlations were found between these two metals and other sediment parameters.

At sites away from the immediate discharge area no interaction was detected between contaminant metals, sediment parameters, and presence or type of seagrass meadow.