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

2. 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

3. 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

4. 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!

5. 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

6. 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

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

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

9. 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)

10. 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...

11. Thanks for your attention!