Usefulness of sediment and three benthic invertebrates as indica tor of organochlorine pollution in an estuarine environment

Because of predominant sedimentation processes in estuaries contaminants tend to accumulate in the benthic system. Sediment and sediment-inhabiting invertebrates are therefore considered suitable as indicators of pollutants. In the Ems Estuary (The Netherlands, Fed. Rep. of Germany) some organochlorines have been discharged in industrial waste water. Four organochlorines (HCB, HCBU, gamma-HCH, dieldrin) and six PCB congeners were analysed in two polychaetes (Arenicola marina, Nereis diversicolor), in a bivalve mollusc (Mya arenaria) and in sediment. It iis concluded that Nereis diversicolor is more usefull for monitoring organochlorines in estuarine systems than the other two species or the sediment.