Genetic changes associated with in-basin supplementation of a population of sockeye salmon

This joint project by NOAA and the University of Alaska Fairbanks evaluates the long term fitness of hatchery and wild sockeye salmon within a small watershed in Southeast Alaska. Concern over preserving wild stock fitness in enhancement project watersheds has been expressed in the case of both the Pacific Salmon Commission (PSC) Transboundary River Plans on the Taku and Stikine Rivers, and the PSC Northern Boundary Treaty Area of Southern Southeast Alaska (Hugh Smith and MacDonald Lakes). Measurement of the fitness effects and potential impact of such enhancement projects is needed to avoid long term undesirable effects on wild stocks. Initial genetic sampling and trial fish culture work in 2008, 2009, and 2010 showed potential for utilizing microsatellite and single nucleotide polymorphism (SNP) markers to assess the parentage of Auke Lake sockeye and to identify the progeny of wild and enhanced fish, and this allows the evaluation of the survival and introgression, if any, of the enhanced fish into the wild population. Furthermore, we have demonstrated the ability to sample very close to 100% of the adult sockeye entering the system and provided a low impact design for sampling, capturing, maturing and spawning small numbers for use as brood stock in this study. During the summers of 2011, 2012 and 2013, we captured and held adult sockeye in the Auke Creek Research hatchery, and conducted experimental matings in all three years. We have incubated, cultured and released approximately 50,000 juvenile sockeye into Auke Lake in the springs of 2012, 2013, and 2014. Complete sampling of upstream migrating adult sockeye has occurred from 2008 thru 2015 and smolt sub-sampling has occurred in May and June of those years as well. Beginning this year, additional objectives will be added to cover the sampling, marking and recovery of coho salmon at Auke Creek. Because of the operational efficiencies and base support this can be accomplished with a small budget increment. Auke Creek is the longest and most complete coho salmon time series in Southeast Alaska, and is used as an indicator of marine survival, harvest and productivity for coho in the region.