Biogeochemistry of Selected Heavy Metals in Western Port, Victoria, and Use of Invertebrates as Indicators with Emphasis on Mytilus edulis planulatus

Abstract

The relationships of Cd, Cu, Fe, Mn, Pb and Zn in sediments, seagrasses, and several invertebrates with geological source areas in the Western Port catchment are examined. Highest concentrations of heavy metals in sediments and seagrasses appear to be derived from an old swamp environment. Highest levels of Cd, Fe, and Pb are found in mussels on the eastern side of the embayment where suspended sediment and detritus from seagrass meadows of the Embayment Head would be carried by the clockwise net circulation in the bay. Zinc distributions are affected by an industrial discharge which has been studied using mussels transplanted from an uncontaminated location. Possible loss of iron and lead from tissues of M. edulis planulatus during freeze-drying was noted and the concentrations of Cd, Cu, Mn, Zn and water content were found to be linear functions of mussel length. The highest levels of cadmium in M. edulis planulatus are found along the non-industrialized eastern side of the embayment. Problems in comparing heavy metal levels in mussels from different areas are discussed.