Considerations of the Introduction and Distribution of Exotic Fishes in Oregon

Many introductions of exotic species have been made without considering the possible effects on native fishes. Of eighty fresh‐water and anadromous fishes of Oregon, nineteen have been established by introduction. Eastern brook trout planted in mountain lakes have produced excellent fishing but numerous introductions in low coastal waters have been unproductive. Spiny‐rayed fishes have replaced trout in some waters and are becoming numerous in the backwater created by the Bonneville Dam on the Columbia River. The increase in predacious fish may lead to the destruction of young salmon during their migration downstream. The introduction of other exotics such as the channel catfish would appear to be undesirable as long as there is hope of maintaining salmonid fishes. Careful biological study of all factors involved should precede the introduction and distribution of exotic fishes in Oregon.