Department Systems Analysis, Integrated Assessment and Modelling

Many rivers in Switzerland and other countries all over the world are affected by channelization, artificial barriers and chemical pollution. These factors have all been shown to have adverse effects on fish; they can lead to diminishing or fragmented fish populations. Barriers in particular reduce the access to refuges, migration to good spawning sites, genetic diversity, and the resilience and sustainability of populations. While the acceptance of restoration measures is wide-spread, predicting their effect and prioritizing such measures remains a challenging task. Stochastic modeling is a promising way to approach this problem, since it can provide well-funded decision support in light of uncertainty. We extend an existing trout population model to a meta-population model for a river network in the Swiss mid-lands for predicting the effects of habitat restoration measures on trout meta-populations.

References

Borsuk, M.E., Reichert, P., Peter, A., Schager, E. and Burkhardt-Holm, P., Assessing the decline of brown trout (Salmo trutta) in Swiss rivers using a Bayesian probability network, Ecological Modelling 192, 224-244, 2006. http://dx.doi.org/10.1016/j.ecolmodel.2005.07.006