MONITORING ORGANOCHLORINES WITH SEMI-PERMEABLE MEMBRANE DEVICES (SPMDS) AND MUSSELS (MYTILUS-EDULIS) IN CORIO BAY, VICTORIA, AUSTRALIA

Semi-permeable membrane devices (SPMDs) and mussels (Mytilus edulis) w ere deployed side-by-side at seven sites in Corio Bay, Victoria, Austr alia, for a period of 60 days in order to test their relative abilitie s to monitor a known gradient of organochlorine contaminants, includin g polychlorinated biphenyls (PCBs) and pesticides. Both SPMDs and muss els provided similar information on the relative levels of organochlor ine contamination. However, the profiles of PCBs differed: SPMDs sugge sted that lower chlorinated PCBs dominated in the water column, whilst mussel data implied essentially the reverse. These differences were a ttributed to contaminant solubility, partitioning of contaminants on s uspended particulates, and possible biotransformation. The accumulatio n by the SPMDs of many early eluting and unidentified halogenated hydr ocarbons, which were primarily absent in the mussels, suggested that t he SPMDs may be capable of more precisely defining the presence of cer tain contaminants in the water column.