Modelling aquatic populations in outdoor mesocosms
The objective of this project is to model the most important biological and physico-chemical processes in small outdoor ponds. Such pond systems are regularly used for testing of aquatic organisms and communities in ecotoxicological field studies (aquatic mesocosms). The development of simulation models for such aquatic ecosystems are intended to make a contribution to answer increasingly complex questions in ecotoxicological risk assessment in the future.
By coupling individual-based population models (IBMs) with water quality models such as the lake model StoLaM, ecotoxicologically relevant organisms can be analyzed under conditions similar to those in the field with variable weather and nutrient conditions as well as dynamic food recources. The population models we used are equipped with toxicokinetic-toxicodynamic (TKTD) submodels to simulate the effects of toxic compounds on the individuals as realistic as possible.
Mesocosm model framework concept
In a pilot study, which was commissioned by industry, we investigated the impact of pesticides on Daphnia magna under complex outdoor conditions. To this end, the lake model StoLaM was coupled with the individual-based Daphnia model IDamP. The resulting hybrid model DaLaM (Daphnia Lake Model) is now able to calculate Daphnia population dynamics under field conditions ( (Stauss et al., 2017)..
Strauss T, Gabsi F, Hammers-Wirtz M, Thorbek P, Preuss TG (2017): The power of hybrid modelling: An example from aquatic ecosystems. Ecological Modelling 364:77-88; https://doi.org/10.1016/j.ecolmodel.2017.09.019
Preuss T, Bruns E, Thorbek P, Hammers-Wirtz M, SchÃ¤fer D, Goerlitz G, Ratte HT, Strauss T (2010): Can population modelling answer urgent unresolved questions for ecological risk assessment - lessons learnt from Daphnia. Poster presentation SETAC Europe, Seville, Spain.
Strauss T, Ratte HT, Hammers-Wirtz M, Thorbek P, Preuss TG (2009): Modeling toxic effects on Daphnia magna populations under natural field conditions. Poster presentation SETAC-Europe, Göteborg, Sweden.
Schematic diagram of DaLaM (Daphnia Lake Model)
gaiac is involved as an associated partner in the EU project "Mechanistic Effect Models for Ecological Risk Assessment of Chemicals ( CREAM)".