The overarching goal of this joint project by the University of Alaska and the Alaska Department of Fish & Game is to use parentage-based tagging over three generations of experimental hatchery supplementation to quantify differences in fitness between wild and hatchery-origin sockeye salmon in Auke Creek, Alaska. Secondary goals of this research are to test for second-generation differences in fitness between wild and hatchery-origin individuals that spawn naturally, and to quantify changes in genetic diversity and population structure in the wild sockeye salmon population as a result of three generations of hatchery supplementation. Results of this study will provide information critical for assessing the relative costs and benefits of hatchery supplementation in managing sockeye salmon populations subject to the Pacific Salmon Treaty.