Préduire les réponses écologiques et évolutives de populations planctoniques à l'exposition chronique de radionucléides induisant différents effets toxiques chez les organismes
Titre du congrès :International Conference on Radioecology and Environmental Radioactivity
Ville du congrès :Bergen
Date du congrès :15/06/2008
Assessing the ecological risk of radioactive substances requires evaluation of effects of acute and chronic exposure to ionising radiation in representative wildlife species. In this aim, a series of experiments was conducted in recent years with the microcrustacean Daphnia magna (Alonzo et al. 2006, 2008a; Gilbin et al., 2008; Zeman et al., 2008). This species is widely-used for investigating toxicity of contaminants in freshwater invertebrates.
Laboratory experiments demonstrated that chronic exposure of daphnids to natural uranium (U), 241americium (Am-241), and 137caesium (Cs-137) caused different perturbations in survival, reproduction, and several other vital functions of organisms (nutrition, respiration, growth and storage of energy reserves). However, these observations were made in laboratory conditions on an individual level, whereas their consequences in a broader ecological context are poorly documented.
In this study, we simulate potential changes in population dynamics in relation to radionuclide effects observed experimentally at the individual level, in order to improve the ecological relevance for risk assessment.