Use of aquatic mesocosms in ecotoxicology: State of the art and perspectives

Ecology and Zoology Laboratory, UPRESA 8079 du CNRS, Ecology, Systematics and Evolution, bâtiment 442, Université Paris-Sud, 91405 Orsay, France

Abstract

Aquatic mesocosms have been used in ecotoxicology for approximately 15 years. They provide a realistic approach for the evaluation of the effects of chemicals at many different levels of organization for different types of organisms. They offer the ability to predict changes at the highest levels of organization (population, community and ecosystem) from measurements of individual endpoints. In the context of hazard assessment, mesocosms can be used to refine estimates of the predicted concentrations in various compartments of ecosystems and of concentrations that will not cause any effect on living organisms. Ecotoxicological investigations in mesocosms will never entirely replace the use of laboratory animals. However, they allow the tests to be performed on species that are not of major "societal" concern, but which play key-roles in the structure and functioning of ecosystems. In this respect, mesocosms allows non-destructive measurements of integrated endpoints. These systems can also be used to identify and quantify links among changes measured at the individual level and their consequences at population and community levels. This paper reviews key features of mesocosms that can be critical for their use in environmental risk assessment of pollutants and emphasises on the optimisation of their use for such purpose.