Habitat requirements of salmonids in streams

Hahitat needs of salmon, trout, and char in streams vary with the season of the YClIr and stage of the life cycle. The major life stages of most salmonid species are IlsslH.:iated with different uses of fluvial systems: migration of maturing fish from .the ocean (anadromous fishes), lakes, or rivers to natal streams; spawning by . udults: incubation of embryos; rearing of juveniles: and downstream migration of juveniles to large-river, lacustrine, or oceanic rearing areas. We present information from the literature and from our own research on the range of habitat wnditions for each life stage that allow the various species to exist. When possible. we attempt to define optimum and limiting conditions. Anadromous sltirnonids of the Pacific drainages of North America are our primary focus, but we h:lve included information on other salmonids to illustrate the ranges of temperlilurc. water velocities. depths. cover. and substrates preferred by salmon, trout, 1I1ll1 char in streams. The scientific names of species identified by common names here are listed in the book's front matter.