1. Karen C. Drayer Wildlife Health Center, University of California Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, California 95965, USA;
2. Kamchatka Branch of Pacific Institute of Geography, Russian Academy of Sciences, ul. Partizanskaya 6, Petropavlovsk-Kamchatsky, 683000, Russia;
3. US Fish and Wildlife Service, Marine Mammals Management, 1011 E Tudor Road, Anchorage, Alaska 99503, USA;
4. Alaska SeaLife Center, 301 Railway Avenue, PO Box 1329, Seward, Alaska 99664, USA;