This project is part of the NWO Stimulation Program System-oriented Ecotoxicological Research. Together with two other PhD projects (E. de Haas and C. Moermond) an effort is made to identify and quantify the coupling of toxicant fate with the carbon and nutrient cycles in a series of floodplain lakes. And to analyse the combined action of changed nutrient and toxicant regimes on natural communities in floodplain lakes and under controlled conditions (model ecosystems). [Aim]: In this project, the interactions between nutrients and contaminants are experimentally analysed, in order to generate new knowledge on the mechanisms as the may occur in floodplain lakes. [Research]: This project consists of five main experiments supplemented with smaller additional experiments. These experiments are conducted with meso- and microcosms (model ecosystems) and focus on trophic status (macrophyte vs. phytoplankton), contamination (polluted vs. non-polluted) and resuspension (resuspension vs. non-resuspension). Endpoints are bioavailability, partitioning and dissipation of HOCs, AVS-profiles, population responses, community metabolism, recovery and fate and food web transfer. Also a field experiment will be conducted with the PhD students of the other two projects to put the gained knowledge of the former experiments to practice.