Comments: See Utter et al. (1989) for information on genetic differences among populations in the Pacific Northwest. In the Nanaimo River, British Columbia, within-stock variation in age of seaward migration of juveniles is a genetic adaptation to local rearing environments; fishes with different life histories had biochemical and morphological differences that were linked to increased fitness in different rearing habitats (see Nehlsen et al. 1991). Waples and Teel (1990) found substantial allele frequency changes over 2-4 years in hatchery, but not wild, populations along the Pacific coast of Oregon.
Has hybridized with pink salmon in the St. Marys River, Michigan (Rosenfield 1998).