Abstract-Zebra mussel (Dreissena polymorpha) is an invasive species that has proliferated in European and North American rivers and lakes during the last century. In this study, D. polymorpha has been used to provide information on contamination levels and biological effects in the Seine Estuary (France). The bivalves accumulated polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) to a high degree with values reaching 800 ng/g dry weight for PCBs (sum of 20 congeners), and 1,000 ng/g dry weight of PAHs (sum of 14 compounds) in the whole body. These values are among the highest reported of PCBs and, to a lesser extent, of PAHs in other contaminated areas in the world. Toxic equivalent quantities of PCBs and PAHs detected in zebra mussels varied from 20 to 40 pg dioxin equivalents/g dry weight for PCBs and up to 120 ng benzo[a]pyrene equivalents/ g dry weight for PAHs, indicating a high potential risk for animals feeding on them. Biological impacts, such as altered condition index, decreased lysosomal stability, and high levels of multixenobiotic resistance (MXR) proteins also were detected in mussels living downstream of Rouen, the main city of the Seine Estuary. Taken together, these results indicate that the Seine Estuary is a heavily polluted area with the potential to cause deleterious health effects in some endogenous living organisms. This study also shows that chemical and biological measurements bring different but complementary results that can help diagnose environmental health.

The Bremerhaven Workshop required chemical data to help interpret the biological findings. Polychlorobiphenyls, organochlorine pesticides, polycyclic aromatic hydrocarbons, total hydrocarbons and trace metals were determined in sediments, dab liver and benthic invertebrates collected at stations along the German Bight and drilllng site transects. In this paper, the chemical data are presented and reviewed.

Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish. We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future.

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analysed in the muscle of various edible marine crustaceans (spider crab, edible crab, velvet swimming crab and Norway lobster) from the Brittany and Normandy coasts (France). The highest concentrations were measured in species collected from Antifer (Seine Bay). PCB and PBDE patterns in crustacean muscles were similar and independent of the geographical area with the predominance of the high chlorinated PCBs (CB153, 138, 118 and 180), and of a few PBDE congeners (BDE47, BDE99, BDE100 and BDE28). Oppositely, dioxin contamination differed with site. The major component in crustaceans from the Seine Bay was 2378-TCDF, whereas specimens from cleaner areas had higher relative concentrations of OCDD. Finally, the comparison of the spider crab contaminant profiles to those measured in mussel and sea bass highlighted two different trends: decapod crustaceans possess relatively strong capacity to metabolise PCBs and PBDEs; however these species might be used as bioindicators for dioxin pollution monitoring in the marine coastal environment.

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