1. School of Aquatic and Fishery Sciences, University Washington, Seattle, WA 98195, USA
2. NOAA, NMFS, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA,
3. Department of Biomedical Sciences, Veterinary College, Cornell University, Ithaca, NY 14853, USA and
4. Friday Harbor Laboratories, 620 University Road, Friday Harbor, WA 98250, USA