1. Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland.
2. Natural Resources Institute Finland, Manamansalontie 90, FI-88300 Paltamo, Finland.
3. Natural Resources Institute Finland, Latokartanonkaari 9, FI-00790 Helsinki, Finland.
4. Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany.
5. Division of Integrative Fisheries Management, Albrecht-Daniel-Thaer Institute of Agricultural and Horticultural Sciences, Department for Crop and Animal Sciences, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115 Berlin, Germany.