1. Ecosystem Management Research Group; Department of Biology; University of Antwerp; Universiteitsplein 1C 2610 Wilrijk Belgium
2. KWR Watercycle Research Institute; PO Box 1072 3430 BB Nieuwegein The Netherlands
3. Department of Aquatic Ecology and Environmental Biology; Institute for Wetland and Water Research; Radboud University Nijmegen; Heyendaalseweg 135 1 NL-6525 ED Nijmegen The Netherlands
4. B-WARE Research Centre; Toernooiveld 1 6525 ED Nijmegen The Netherlands
5. Chemical Analytics and Biogeochemistry; Leibniz-Institute of Freshwater Ecology and Inland Fisheries; Müggelseedamm 301 D-12587 Berlin Germany
6. Department of Bioscience; Aarhus University; Vejlsøvej 8600 Silkeborg Denmark
7. Institute of Landscape Ecology and Site Evaluation; University of Rostock; Justus-von-Liebig-Weg 6 18059 Rostock Germany