1. Greenland Institute of Natural Resources, Strandgade 91, 2, DK-1401 Copenhagen, Denmark.
2. Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA.
3. Norwegian Polar Institute, Fram Centre, N-9296 Tromsø, Norway.
4. A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow 119071, Russia (Independent scientist, Kharkov, Ukraine).
5. Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
6. DTU Aqua, Technical University of Denmark, Lyngby, Denmark.