ChimERA: integrating fate and effect modelling

Modelling is increasingly becoming more integrated in ecological risk assessments, both for exposure and effect assessment. Models allow for a more realistic assessment of the ecological risk but are not yet used to their full potential. The objectives of the ChimERA project were (i) to incorporate spatially and temporally heterogeneous exposure patterns, (ii) to assess how ecological interactions alter chemical effects and (iii) to develop a modelling framework that closely links chemical fate and effects models. To demonstrate the added benefit of this integrated approach, the ChimERA model was used to predict chemical effects in pond communities for 15 hypothetical scenarios, differing in the applied chemical, nutrient status, temperature and water flow. Both direct and indirect effects of these chemicals were predicted by the model corresponding to the sensitivities of the species. These effects were, however, heterogeneously distributed in space and time and reflected differences in exposure. These simulations demonstrate that the outcome of chemical exposure is determined by both the environmental and ecological conditions, which is difficult to capture with traditional risk assessment methods. Modelling tools like the ChimERA model can prove essential to answer current and future challenges for ecological risk assessment.