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2C - Biomarkers (TUP/93) Embryotoxicity of PCBs in the sea star Asterias rubens. Danis, Bruno1, Warnau, Michel2, 1 Université Libre de Bruxelles, Brussels, Brussels, Belgium2 International Atomic Energy Agency-Marine Environment Laboratory, Monaco, Monaco, Principalty of Monaco ABSTRACT- The asteroid Asterias rubens, a key species of the North Sea, was selected as a model to investigate the effects of 10 PCB congeners (IUPAC #28, 52, 77, 101, 118, 126, 138, 153, 169, 180) on its early development. Embryos and larvae were exposed to a range of concentrations of these congeners (1.6 to 5000 ng l-1) to test for the induction of developmental aberrations. Morphological abnormalities (ranging from retarded larvae to severe malformations) were caused by every PCB congener. Most frequent observations were gut malformations and arrested development of pathological blastulae. Overall results indicate that even at the lowest concentrations considered in this study, the number of normal larvae was significantly decreased for all congeners. A dose-dependent relationship was found for each congener, both for abnormalities frequency and for malformation severity. EC50s were calculated for each congener. In terms of non-viable larvae occurrence, coplanar PCB were up to two orders of magnitude more toxic than non-coplanar congeners. These toxic levels correspond to concentrations actually reported in heavily contaminated environments, indicating that impairment of normal sea star development and settlement due to PCB contamination may occur in the field. This study confirms the high toxicity of PCBs towards sea stars embryos and the contrasted behaviour of coplanar vs non-coplanar congeners. It is concluded that this biomarker is worth integrating with others in the detection, survey and monitoring of environmental PCB contamination. Key words: Embryotoxicity, Asterias rubens, PCB, Biomarker |
