Renaturalised Nidda. Source: Robert Marc Lehmann /

Use of effect-based monitoring methods to evaluate the effects of pollutants on water ecology (EffektMon)


In accordance with the objectives of the European Water Framework Directive (WFD), at least a “good” ecological status is to be achieved in all surface water by 2027, at the end of the third planning cycle. Yet, the most recent estimates from the European Environmental Agency concluded that less than 10 % of Germany’s running water bodies meet this objective. One of the main underlying causes for the ecological impairment of lotic ecosystems is the excessive discharge of nutrients and pollutants such as pesticides or pharmaceutical waste.

However, the identification of significant sources of pollution and their contribution to the deficient status of water bodies is complex.  For technical and economic reasons, current chemical monitoring methods are limited, resulting in the inability to analyse, detect and quantify the majority of the pollutants and mixtures of substances present in the aquatic environment, constraining water managers and decision-makers. Moreover, chemical analyses cannot predict the toxic effects of the mixtures of substances present in water or sediment, the so-called cocktail effects. Furthermore, such effects can be overlaid or interact with other stressors (e.g. hydromorphological degradation).

Therefore, it is a challenge to link scientifically sound and cost-effective guidelines in water quality monitoring with chemical and ecological assessments. A promising approach for this is the application of effect-based methods (EBM), such as bioassays and biomarkers that provide an integrative approach to risk assessment, thereby detecting adverse effects or potentials from toxic chemicals. Using such effects-based monitoring, cumulative effects of a general or specific nature, as well as the combined effects of mixtures of compounds, can be addressed. The goal of the EffektMon project is the development and application of EBM, providing a comprehensive toolbox for actors in water and wastewater management.


In this project, EBM are used to investigate the importance of pollutants from diffuse inputs and point sources for the failure to achieve good ecological status. It is investigated which of the numerous effect-based methods are suitable for this and ideally can be used in the future. In addition, it should be clarified how the results of the individual test procedures are to be offset against one another.

The overarching goal of the project is the development of an ecotoxicological assessment system as an innovative system solution for the assessment of running waters, which ultimately serves as the basis for sustainable water management in water management practice.

For this purpose, the effect-based monitoring is carried out at the Alb in Karlsruhe, for which high-quality water-chemical data is available. The comparison with measured pollutant concentrations enables a plausibility check of the results from the EBM. To compare the EBM results with the ecological status according to the WFD, the benthic invertebrates are recorded. Potential interacting stressors (e.g. hydromorphological degradation or land use) are recorded in advance and also taken into account. The investigations are carried out, among other things, in restored and nearby non-restored river sections throughout Germany. The aim here is to examine the extent to which water pollution in restored river sections counteracts the achievement of a good ecological status.


Senckenberg Gesellschaft für Naturforschung
PD Dr. Andrea Sundermann, Ariane Moulinec
Tel.: +49 (0) 6051 61954 3124

Goethe-Universität Frankfurt
Dr. Matthias Oetken, Sarah Hörchner
Tel.: +49 (0) 69 798 42148

Mesocosm GmbH – Institut für Gewässerschutz
Prof. Dr. Peter Ebke, Thomas Bing
Tel.:+49 (0) 6633 82549 10

Specialist support:

Dr. Jens Arle
Tel.: +49 (0)340 2103 2511

Ingo Warnke
Tel.: +49 (0)340 2103 2905