Gulf of Alaska | Fishes and Fish Habitats DOCTORATE ORAL PRESENTATION Investigation of the influence of hatchery straying on the population structure of pink salmon in Prince William Sound, Alaska Presenter: Wei Cheng , wei.cheng@alaska.gov, Genetics Laboratory, Division of Commercial Fisheries, Alaska Department of Fish and Game Christopher Habicht , chris.habicht@alaska.gov, Genetics Laboratory, Division of Commercial Fisheries, Alaska Department of Fish and Game William Templin , bill.templin@alaska.gov, Genetics Laboratory, Division of Commercial Fisheries, Alaska Department of Fish and Game Zac Grauvogel , zac.grauvogel@alaska.gov, Genetics Laboratory, Division of Commercial Fisheries, Alaska Department of Fish and Game Anthony Gharrett , a.gharrett@alaska.edu, College of Fisheries and Ocean Sciences, University of Alaska Fairbanks Pink salmon ( Oncorhynchus gorbuscha ) are commercially and ecologically important in Alaska. In the 1970s, the abundance and harvests of Pacific salmon declined in Alaska, including pink salmon in Prince William Sound (PWS). In response to this low abundance, State of Alaska passed legislation that provided the opportunity for Private-Non Profit (PNP) corporations develop hatcheries to supplement commercial harvest. In three years with full run reconstruction (2013-2015), 55 - 86% of the returning pink salmon in PWS originated from PNP hatcheries. Such large scale hatchery programs have raised concerns regarding the potential effects of hatchery salmon on wild salmon populations. The state, hatchery operators, and processors pooled resources to fund the Alaska Hatchery Research Program (AHRP) to investigate some of these potential effects. One of the primary goals of the AHRP was to investigate the genetic population structure of pink salmon in PWS. In this study, we examined variation at 16 microsatellite loci from wild spawning aggregates and hatchery fish from collections from the1990s’ and more recent collections (2013 and 2014). We examined even and odd year fish separately, since their 2-year life history results in two genetically independent lineages. As with previous studies, we detected deeper population structure among wild populations within the odd year lineage than the even lineage. We found that hatchery stocks in PWS had maintained stable allele frequencies between the 1990’s and 2010’s. In the even lineage, our results are consistent with the hypothesis that western PWS hatchery fish have introgressed genes into wild populations, while we found no support for introgression from the eastern PWS hatchery. However, in the odd years, we found no support for the introgression hypothesis from any hatcheries. Finally, we explored the source-sink model to measure the level of genetic introgression from hatcheries to wild populations over generations.
Alaska Marine Science Symposium 2023 17
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