1. Marine Mammal Institute, Department of Fisheries and Wildlife, Oregon State University, Hatfield Marine Science Center, Newport, OR 97365, USA
2. Institute of Ecology and Evolution of the Russian Academy of Science, Moscow 119071, Russia
3. School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington DC 98195-5020, USA
4. Kronotsky State Nature Biosphere Reserve, Elizovo, Kamchatka 684010, Russia