1. Institute of Marine Research, Fram Centre, PO Box 6606, Langnes, Tromsø 9296, Norway
2. Fisheries and Oceans Canada, Maurice Lamontagne Institute, 850 route de la Mer, Mont-Joli, QC G5H 3Z4, Canada
3. University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, 17101 Point Lena Loop Road, Juneau, Alaska 99801, USA