1. WasserCluster Lunz Biologische Station GmbH, Lunz am See, Austria
2. Danube University Krems, Krems, Austria
3. Department of Biology, University of Turku, Turku, Finland
4. Department of Geography and Geosciences, GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany