Research needs derived from MODELKEY findings Werner Brack et al. Helmholtz Centre for Environmental Research - UFZ

Complexity Complexity of chemosphere (more than 50 mio) Complexity of effects biochemistry → ecology Science: understand the system provide applicable tools Complexity of exposure (bioavailability) water manager Complexity of stressor interactions, multiple stress, indirect effects Complexity of ecology of recovery Complexity of space scales from local to basin scale

Complexity of Effects Research needs: We can observe effects on different levels of biological organisation Increase in EC50 Research needs: Holistic diagnosis on health status of organisms exposed to stress  “omics” Mechanistic understanding and prognostic tools for effect propagation on higher biological levels Diagnosis of ecosystem stability (structure, functions, species composition) → prediction of regime shifts or extinction of species PICT in vitro community level SPEAR in vivo

Complexity of Chemosphere We made significant progress in identifying hazardous compounds in complex mixtures: biological detection, fractionation, analysis, computer tools for structure elucidation ..... Research needs: Analytical tools, databases and computer tools for structure elucidation of difficult (polar, thermolabile, multifunctional….) unkowns. Reliable tools for prediction of chromatographic retention, spectroscopic properties and effects Integrated approaches for compound prioritisation However, we still see only the top of the iceberg!

Complexity of Exposure We have nice conceptual models and experimental approaches to predict and simulate bioavailability: Equlibrium partitioning (activity), bioaccessibility (desorption)  in some cases nice predictions Research needs: Ecological or biological factors may confuse our attempts to estimate bioavailability of chemicals in sediments  Improve our understanding of chemical and biological interactions. Prediction of bioavailability from matrix properties Predict stability of bioavailability in different milieus (transport, uptake, climate change) In other cases no prediction at all

insufficient ecological status Multiple Stress: Challenge for Water Management hydromorphology oxygen depletion pathogens invasive species nutrients complex mixture of chemicals organisms, populations, communities, ecosystem goods and services ? diagnosis and prognosis? understanding of interactions? prioritization? effective management? insufficient ecological status

Multiple Stress Multiple stress and indirect effects as frequent phenomenon Example: Toxicants and pathogens

Multiple Stress We can statistically diagnose multi-stress impacts and understandably present results GREY ? Interactions

Multiple Stress Research needs: We can mechanistically model multi-stress impacts in simplified systems Toxicant from emissions Toxicant in biota and water Research needs: Overall concept for understanding and predicting multiple stress (based on existing tools: statistical models, mechanistic models, mixture tox. models..) Validation in the ecosystem Diagnostic tools to measure and discriminate different stress (omics, biomarkers, stressor-specific indexes)

Water pH, or toxic pressure, or... Ecology of Recovery Key question for watermanagers: What will be the effects of measures? Will the system recover? In which time frame? Basis :  species – stressor relationships + model + monitoring action Management action: Change per species Up , Down , Neutral  Yields (aggregated) * Change of Biodiversity * Change of Stability Research needs: Better understanding of species-stressor relationships and operationalization for management scenarios Pilot studies accompanying mitigation measures Species abundance And now towards prognosis. Nothing is more frustrating that to see that management does not work. Costly measures have been defined on the basis of diagnosis, but the system fails to recover! This can be circumvented by prognosis. Prognosis involved a suite of methods, like e.g. biogeography and the analysis of “refugia”, sites from which “lost species” can re-enter a system. In this case, I restrict myself to the re-use of the analyses already made. In diagnosis, we know the association between site stressors and species abundances. This graph shows, as an example, such associations. When management would imply e.g. a reduction of x% of stress on the x-axis, one can predict the direct abundance responses of all species, and thus evaluate whether the system could move towards recovery and Good Status. An horizontal line would indicate: failure of management to result in change! Water pH, or toxic pressure, or...

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