Didier Claisse

Chemical contamination of French coasts: The Results of a Ten Years Mussel Watch

On controle les teneurs en mercure, cadmium, plomb, hydrocarbures polycycliques aromatiques, PCB, DDD, DDE et DDT dans les especes Mytilus edulis, Mytilus galloprovincialis et Crassostrea gigas. Ces bivalves sont des indicateurs du niveau de pollution dans les eaux de mer cotieres de France

Copper contamination as a result of antifouling paint regulations

Abstract Results from a monitoring programme conducted in the Bay of Arcachon between 1979 and 1991 reveal an increase of copper content in oysters harvested in a zone located in the vicinity of marinas and mooring areas. This clearly perceptible increase recorded since 1982, may be attributable to the growing use of copper paints subsequent to the antifouling paint regulations adopted in 1982.

EROD measurements in fish from the northwest part of France

Abstract In this study, EROD activity (7-Ethoxyresorufin O-deethylase) was measured in plaice ( Pleuronectes platessa ) and callionyme ( Callionymus lyra ) from the bay of Seine, France. A new methodology based on the use of the fluorescence microplate reader was used. This methodology enables numbers of measurements of EROD activity to be measured directly onboard ship with the advantage of simplicity and is well adapted for monitoring purposes. A seasonal variation study of EROD activity in plaice from a reference site showed an increase during the reproductive season. Results obtained in field experiments demonstrate the ability of measuring EROD activity induction in both plaice and callionyme for monitoring the effect of pollutants of the Seine River. Ten individuals were analyzed for PCBs and HCH concentrations. A correlation was observed between EROD activity in plaice and PCBs and HCH contents (0.62 and −0.69 respectively). The results establish the use of microplate reader as a tool for monitoring the environmental induction of EROD and the ability of using both plaice and callionymes in the bay of Seine.

Seasonal and Decadal Variations in Lead Sources to Eastern North Atlantic Mussels

The concentration of Pb and its stable isotope composition were measured in 216 composite samples of 50 blue mussels (Mytilus edulis (M. edulis)) collected quarterly between 1985 and 2005 at three sites along the French Atlantic coast, one in the La Fresnaye Bay and the others in the Loire and Seine River estuaries. Depending on the sites and time periods, Pb concentrations were 5-66 times higher than the natural background value for the North Atlantic. Even for the samples with the lowest Pb concentrations, the isotopic signature of Pb is very different than that of the regional natural Pb, suggesting that most of the bioaccumulated Pb is anthropogenic in origin. Stable Pb isotope ratios measured in the mussels differ markedly from that of Pb emitted in Western Europe as a result of leaded gasoline combustion, which was still a dominant source of contaminant Pb to the atmosphere during most of our study period. The isotope composition of Pb in the mussels was instead more typical of that of the Pb released to the environment by wastewater treatment plants, municipal waste incinerators, and industries such as metal refineries and smelters. Continental runoff, rather than atmospheric deposition, is therefore identified as the leading transport pathway of Pb along the French Atlantic coast. From the strong seasonal variations in (206)Pb/(208)Pb ratios in the mussels from the Seine Estuary site we also conclude that the resuspension of contaminated sediments, triggered by high river runoff events, is a chief factor affecting the bioaccumulation of Pb in M. edulis . The value of this organism as a biomonitor of coastal contamination is thus further demonstrated.