Re-introduction of bull trout to the Clackamas River, Oregon, U.S.A.

Summary

Bull trout (Salvelinus confluentus), federally threatened and extirpated from Oregon's Clackamas River by 1990 alongside four other historic Willamette River tributaries, is the target of a 20-year adaptive reintroduction launched in July 2011 by the US Fish and Wildlife Service, US Forest Service and Oregon Department of Fish and Wildlife, aiming to establish 300-500 self-sustaining spawning adults by 2030. A 2004-2007 interagency feasibility assessment, evaluating extirpation confidence, habitat suitability, natural recolonization potential, and available donor stocks, concluded the Clackamas River could support reintroduction using low-risk extractions from Deschutes River Basin donor populations, co-managed with the Confederated Tribes of the Warm Springs Reservation, whose early engagement was essential to securing tribal support. The project proceeds under the Endangered Species Act's less restrictive experimental nonessential population designation to reduce regulatory burden on private and public landowners and ease stakeholder concerns about impacts on threatened Pacific salmon. Implementation, structured in three equal phases, involves direct translocation of roughly 60 adults and sub-adults plus up to 1,000 juveniles annually during phase one, with continued releases contingent on ongoing evaluation against three explicit stop conditions: meeting the population goal, signs the project won't succeed, or unacceptable impacts to Pacific salmon. Major difficulties included scientific uncertainty over predation and competition effects on salmon and securing sustained funding for monitoring. Because the project began only in July 2011, the report explicitly states it is too early to assess success, and no rating is given.