1. a Bowdoin College , Brunswick , Maine , 04011 , USA
2. b National Oceanic and Atmospheric Administration, Northwest Fisheries Science Center , Newport , Oregon , 97365 , USA
3. c National Oceanic and Atmospheric Administration, Alaska Fisheries Science Center , Newport , Oregon , 97365 , USA
4. d Cooperative Institute for Marine Resources Studies, Oregon State University , Newport , Oregon , 97365 , USA