Eastern Brook Trout
Scientific Name: Salvelinus fontinalis
Identifying Characteristics: Like all salmonids, brook trout have a fleshy adipose fin located between the dorsal fin and caudal fin (tail). Brook trout can be distinguished from other salmonids by the dark vermiculations (wavy lines) on their back, a dorsal fin with black markings, sides having small lateral red spots with blue halos, a nearly squared or slightly forked caudal fin and pectoral, pelvic, and anal fins with white leading edge with an interior black line.
Status: Not native in the Pend Oreille Watershed. Eastern brook trout are classified as a “game species” by WDFW.
Distribution: Eastern brook trout were introduced to the Pend Oreille River and its tributaries via hatchery planting. Intermittent stocking of hatchery brook trout continued into the 1990s (Bennett and Garret as cited in GEI Consultants 2004). Currently, brook trout are abundant and well distributed throughout the Pend Oreille watershed (WCC 2003). Their distribution overlaps throughout much of the historic range of bull trout and westslope cutthroat trout in the watershed, including portions of nearly all spawning and rearing streams (GEI Consultants 2004).
Species Notes: Brook trout are problematic to westslope cutthroat trout due to competition for space and resources, predation risk, and the ability to establish and reproduce quickly. Also as problematic to bull trout, brook trout can hybridize with bull trout creating a sterile offspring. Brook trout has been targeted by the Kalispel tribe of Indians and the Washington Department of Fish and Wildlife for eradication in specific, localized, stream reaches. This is part of a larger objective to reintroduce native westslope cutthroat trout to historically occupied reaches in the Pend Oreille Watershed.