The bioaccumulation pattern of organochlorine residues in Lanice conchilega (polychaeta) and its geographical variation between the English channel and the German bight

Abstract

PCBs, p,p′-DDE, HCB, α-HCH and γ-HCH were analysed in Lanice conchilega from the French, Dutch and German coasts. The annelid exhibited a species-specific PCB pattern. It showed lower and higher chlorinated congeners in more balanced quantities than the polychaete Nereis diversicolor and also the bivalve Mytilus galloprovincialis used in the French mussel watch programme RNO. The PCB pattern in L. conchilega was influenced by the geographical location, probably by changes of the environmental PCB composition from SW to NE. Riverine influences could be distinguished from regional ones. Contributions of higher chlorinated PCB congeners increasing from western to eastern river-related positions are explained by fractionation of PCBs during atmospheric transport. Concentrations of PCBs and p,p′-DDE in L. conchilega based on extractable organic matter were highest in the Seine Bay indicating a substantial input of these pollutants by the river Seine. No enhanced PCB and p,p′-DDE values were measured in the German Bight. Levels of γ-HCH and ratios of γ-HCH/α-HCH were elevated near the mouths of Rance and Seine, which drain areas of intensive agriculture with apparent lindane application. Balanced levels of HCB point to fast atmospheric transport and homogenous deposition of this compound into the sea.