Population Structure of Odd-Year Pink Salmon from Prince William Sound, Alaska

Pink salmon are the most abundant Pacific salmon species in the world and support the largest commercial fishery in Prince William Sound (PWS); over 91 million pink salmon were harvested in PWS in 2013. Along with natural production, four private non-profit hatcheries in PWS also provide salmon for harvest.   Approximately 90% of pink salmon returning to PWS are of hatchery origin. Concerns about the effects of hatchery fish on wild fish have been voiced, but limited information exists to examine interaction between wild and hatchery fish in PWS.  The last survey of population structure for pink salmon in PWS was in the 1990’s, over 10 generations ago for these obligate two-year spawners.  More contemporary information may provide insights regarding the genetic interaction between hatchery and wild pink salmon in PWS. To study the population structure, we first surveyed variation at 16 microsatellite loci from approximately 3500 contemporary individuals and 3500 historical samples from 24 locations from one of the two brood lines (odd-year). We tested for evidence of structure among populations at fine- and broad-spatial scales and between contemporary and historical samples.