Claude Alzieu
IFREMER
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Featured researches published by Claude Alzieu.
Marine Environmental Research | 1991
Claude Alzieu
Abstract The sea water pollution resulting from the tributyltin (TBT) released by antifouling paints has had serious consequences on the oyster production in a number of bays along the French coastline. Effects of this pollution on oyster growth and reproduction, as well as its economic impact in the Bay of Arcachon are reviewed. The influence of the ban on TBT use in antifouling paints on the recovery of the oyster stock is discussed in an attempt to reflect on the strategy required to protect the marine environment.
Science of The Total Environment | 2000
Claude Alzieu
The deleterious effects of TBT released by antifouling paints were first documented in Arcachon Bay (France) at the end of the 1970s. As a result of the high level of water contamination, the production of Pacific oysters was severely affected by a complete lack of reproduction and the appearance of calcification anomalies which were responsible for a strong decline in the marketable value of the remaining stock. Regulations that had been successively adopted from January 1982 had positive effects on the recovery of the oyster grounds by reducing ambient water concentrations. Most antifouling paints act by releasing toxicants into the water which avoid the fixation of the organisms responsible for fouling. The use of these paints results in significant inputs of biocides in the waters. The harmful effects on non-target organisms were first evidenced in the bay of Arcachon (France) where the most acute disturbances were recorded following tributyltin (TBT) contamination.
Ecotoxicology | 2000
Claude Alzieu
Organotins, and more specifically tributyltins (TBT), are introduced into the marine environment by paints designed to protect ship hulls against biological fouling. Lab tests have shown that bivalve reproduction is affected by TBT concentrations exceeding 20 ng⋅l−1. A dose-effect correlation scale describes the effects on embryogenesis and on larval growth: total larval mortality occurs after 12 days of exposure at a concentration of 200 ng⋅l−1, and inhibition of fertilization at 100 μg⋅l−1. At concentrations close to 1 ng⋅l−1, significant changes are observed in the sexuality of marine gastropods, reflected in an imposition of male characters in females, a phenomenon known as imposex. Imposex evolution in Nucella lapillus females includes: formation of a vas deferens, a channel between prostate and penis existing in males (phase 1), appearance and growth of a penis (phases 2 to 4), sterilization of the subject with blocking of the oviduct and accumulation of eggs within the gland (phases 5 to 6). In the final stages, females become sterile, thereby jeopardizing population renewal. These disturbances occur following exposure at TBT concentrations of 7 to 12 ng⋅l−1 approximately. Physiological and biochemical phenomena leading to imposex are still not well understood. However, there are evidences that TBT exposure tends to increase the testosterone contents in female mollusks, while progesterone and 17 E oestradiol levels remain constant. Since testosterone alone causes penis growth in the females, it is thought that imposex could be attributed to its accumulation originating from inhibition of cytochrome P450-dependent aromatase. The conversion of testosterone into 17 E oestradiol would then be inhibited by TBT. In spite of regulations banning the use of TBT as biocide in antifouling paints, current TBT contamination in coastal areas frequently reaches concentrations likely to cause imposex.
Marine Environmental Research | 1991
Claude Alzieu; P. Michel; I. Tolosa; E. Bacci; Laurence D. Mee; J.W. Readman
Abstract Extensive survey data for butyltins are reported for Mediterranean coastal waters together with the first phenyltin concentrations from the region. Elevated levels of tributyltin (TBT) are reported for most marina/harbour waters. In the great majority of cases, the ‘no observable effect’ aqueous concentration of 20ng litre−1 is exceeded. The TBT concentrations encountered are comparable to those reported in a previous MEDPOL pilot survey. This questions the efficacy of current legislation in the Mediterranean. The movement of foreign vessels painted outside of the scope of legislation offers an explanation for this observation and endorses the need for region-wide control measures and enforcement. The Contracting Parties to the Barcelona Convention have recently agreed to adopt such control measures to protect the Mediterranean; these are described and discussed. Concerning triphenyltin, concentrations of 21–94 ng litre−1 are reported, with most of the compound associated with the particulate phase. The distribution in samples collected from marinas and in proximity to dry docks attributes the origin of the compound to antifouling paint leachates.
Ocean & Coastal Management | 1998
Claude Alzieu
Revue des Travaux de l'Institut des Pêches Maritimes | 1981
Claude Alzieu; Maurice Heral; Yves Thibaud; Marie-Jose Dardignac; Michèle Feuillet
Revue des Travaux de l'Institut des Pêches Maritimes | 1980
Claude Alzieu; Yves Thibaud; Maurice Heral; Bernard Boutier
Aquatic Living Resources | 1990
Dominique Chagot; Claude Alzieu; Jane Sanjuan; Henri Grizel
In : Ecotoxicological Testing for the Marine Environment; G. Persoone & al. (Eds.), Ghent & Inst. Mar. Scient. Res., Belgium | 1984
Claude Alzieu; Maurice Heral
Applied Organometallic Chemistry | 1990
Claude Alzieu; Pierre Michel; Jane Sanjuan; Bernard Averty