1. National Institute of Aquatic Resources, Technical University of DenmarkVejlsøvej 39, 8600 Silkeborg, Denmark
2. Department of Biological Sciences, Genetics and Ecology, University of AarhusBuilding 1540, Ny Munkegade, 8000 Aarhus C, Denmark
3. Mammal Research Institute, Polish Academy of SciencesWaszkiewicza 1c, 17-230 Bialowieza, Poland
4. Danish Centre for Wild SalmonBrusgårdsvej 15, 8900 Randers, Denmark