In the south-east of France, on the nearly clear waters of the Rhône, an inflatable boat cuts through the morning mist. On board, scientists and volunteers tirelessly cast and retrieve two floating nets. The aim of this three-week mission, conducted in April by the National Centre for Scientific Research (CNRS), is to understand how microplastics — carried by river pollution — interact with living organisms. "We want to know, in fact, if plastics will be a vehicle for these chemical products in the environment," says Jean-François Ghiglione, director of research in marine microbial ecotoxicology. IMAGES AND SOUNDBITES