Relaxed selection in salmon hatcheries

Hatchery fish are a significant component of fisheries subject to management under the Pacific Salmon Treaty (PST), and research on the costs and benefits of additional enhancement opportunities is a priority of the Northern Fund. The genetic risks of hatcheries, including potential loss of fitness to wild stocks, have been a long-standing concern (Waples and Do 1994, Naish et al. 2008, Grant et al. 2017). This study will investigate domestication in hatchery populations arising from relaxation of natural selection, a little-studied pathway for hatchery-induced changes. The results could have implications for the design of additional enhancement efforts as well as for practices at current enhancement facilities.