Modelling ecological scenarios for the assessment of
chemical effects on aquatic communities
Andre Gergs1, Silke Classen1, Annemette Palmqvist2, Tido
Strauss1, Wolfgang Zuleger3, Monika Hammers-Wirtz1
1gaiac - Research Institute for Ecosystem Analysis and
Assessment, Kackertstr. 10, 52072 Aachen, Germany2Department of
Environmental, Social & Spatial Change - Roskilde University,
Universitetsvej 1, 4000 Roskilde, Denmark
3 Dr. Knoell Consult GmbH, Marie-Curie-Straße 8, 51377
Leverkusen, Germany
Project scope
Chemical effects
time
x
toxicokinetics
internalconcentration
toxicodynamics
effectmodel e
ffect
exposure
TK-TD modelslink exposureand (sub)lethaleffects.
Habitat preference
Habitat preferncetrait triggersspatial distribution.
Stream sections representstream habitat typologies.
Stream section raster maps serve as virtual landscapes.
Individuals of the same and of different species interact.
Time [d]
0 100 200 300
Popula
tion d
ensity [#/L
]
0
20
40
60
80
100
Temporal dynamics emergefrom individual interactions.
Life histories
time
Dynamic energybudget modelsdecribe animal lifehistory
processes.
reserve
faeces
food reproduction
maturation
growthsomatic maintenance
maturity maintenance
Project objectives
• Identification of relevant ecological scenarios
• Development and implementation of a standardized
individual-based stream community model
• Comparison of community level toxicity model outcomes and
conventionally calculated Predicted No Effect Concentrations by
applications of lake and stream models
• Development of a conceptual framework for adopting community
models into the ecological risk assessment of chemicals
• Ecological risk assessment of chemicals aims at quantifying
the likelihood of adverse effects posed on the environment.
• Effects can to a great extent depend on the environmental
scenario as well on the states, behaviours and interactions of
organisms.
• Mechanistic effect models, such as individual based models,
are expected to facilitate the lab to field extrapolation of
effects by integrating ecological realism into ecological risk
assessment .
This study is financially supported by the CEFIC Long-range
Research Initiative under project number ECO28
Project outcome
• Suggestions on the integration of ecological scenarios in the
ecological risk assessment of chemicals using mechanistic effect
models
• Test of trait based toxicokinetic toxicodynamic models for the
extrapolation of lethal and sublethal effects across species
• Simulation tool for the prediction of community level effects
in the field based on single species laboratory toxicity tests
Food preference
Model elements for ecological scenarios
Functional diversity emergesfrom temporal dynamics.
Food preference traittriggers competionand predation.
Habitat preference
POM
Phytal
Lithal
Akal
Psammal0
20
40
60
80
100
Re
lative
ab
un
da
nce
[%
]
Food preference
Predator
Filterer
Detritivore
Shredder
Grazer
