Concentrations of some heavy metals in Mytilus edulis (Cd, Cr, Cu, Fe, Mn, Pb and Zn), Ostrea angasi (Cd, Cr, Cu, Pb and Zn). Portunus pelagicus (Cd, Cu, Pb and Zn), Chaetopterus variopedatus (Cd, Cu and Zn), Posidonia spp. and their epiphytes (Cd, Cu, Fe and Zn), and Ulva lactuca (Cd, Cu, Fe. Mn, Pb and Zn) from Cockburn Sound, Western Australia, are reported. The highest concentrations of Cd; Cr and Pb in M. edulis and Cd and Zn in O. angasi were found in those animals taken from the vicinity of industrial effluent discharge points. Further, elevated concentrations of some metals were noted in the hepatopan- creas of Portunus pelagicus and in C. variopedatus and U. lactuca. Significant correlation coefficients for Cd-Cu, Cd-Fe, Cd-Zn, Cu-Fe, Cu-Zn and Fe-Zn in M. edulis indicated that elevated heavy metal levels resulted from industrial effluent discharges. Significant correlation coefficients for Cd-Zn and Cd-carapace width were found in the female crab P.pelagicus only. C. variopedatus and U. lactuca, unlike Posidonia spp. and their epiphytes, showed potential as trace metal indicators.