Technical Recommendation 5
Use supplementation to reintroduce salmon to watersheds from which they have been eliminated.
As recommended, several programs to reintroduce extirpated stocks have been enacted within the interior Columbia Basin, primarily through initiatives of the tribes. Examples of tribally managed reintroduction programs are shown below.
Examples of tribally managed reintroduction programs
|Escapement goal||Recent 5-year average|
|Program||Total||Natural origin||Total||Natural origin|
|Hood River spring chinook||n/a*||205||n/a*||206|
|Yakima River coho||5,000||3,500||6,978||1,840|
|Yakima River summer chinook||n/a*||n/a*|
|Cle Elum Lake/River sockeye||n/a*||n/a*|
|Wenatchee River coho||1,500||10,914||502|
|Methow River coho||1,500||2,647||64|
|Umatilla River spring chinook||8,000||2,000||2,900||200 (?)|
|Walla Walla River spring chinook||5,500||2,500||539||216|
|Clearwater River coho||3,946||n/a*|
|Lookingglass Creek (Grande Ronde River) spring chinook||2,000||1,000||431||115|
*n/a: not [yet] available/applicable
The programs were each initiated by importing juveniles from non-endemic hatchery stocks. Many of the fish were released from hatcheries or other locations in-basin to facilitate the recapture of returning adults for use as broodfish to help create a new localized stock. Over time, release of the non-endemic juveniles has diminished as the programs transition to production of local fish. In several programs, this transition is complete. Over this same period, an increasing proportion of the juveniles have been released at sites in proximity to natural spawning areas to further promote naturalized populations. When feasible, the juveniles are held in acclimation facilities prior to release, typically for 4-6 weeks, to encourage homing to these new spawning areas.
Each of the reintroduction programs has seen growth in both adult escapement, annual redd counts and production of naturally spawned juveniles, which suggests that new localized natural populations are being established. Additionally, returns have been sufficiently high in many cases to reinstate limited tribal fisheries at usual and accustomed places.
These programs are progressing toward their goal of reestablishing viable natural populations, despite the highly domesticated nature of some of the non-endemic hatchery stocks used to initiate the reintroductions. (“Highly domesticated” refers to those stocks in segregated rearing for 10 to 20 generations.) Recently, hatchery programs to supplement natural populations have come under substantial criticism, because of a belief that rearing within a hatchery environment, purportedly even for as little as one generation, will have a substantial negative effect on fitness of the natural population with which they interbreed (Araki et al. 2008, Christie et al. 2011). However, the apparent rapid readaptation of the reintroduced fish to the natural environment observed in these programs suggests that fitness changes that may accrue in a hatchery stock are susceptible to reversal in the face of natural selective processes and judicious management of broodstock and hatchery rearing.
Fraser (2008) reviewed reports for 31 salmonid reintroduction programs. He cautiously stated that evidence was insufficient to definitively conclude whether the programs had been successful or not in establishing new self-sustaining natural populations. The reasons given, however, were that the programs had not been in place for sufficient numbers of generations and/or that the environmental factors responsible for extirpation of the stocks had not been sufficiently mitigated for. The tribal programs in the Columbia Basin are relatively new, and habitat and hydrosystem problems continue to constrain rebuilding. For the short-term at least, supplementation of reintroduced stocks is required. Also, infrastructure, operation and monitoring activities for these programs have generally been underfunded. Nonetheless, the dramatic increases in escapement and natural spawning are highly encouraging.
New and Modified Actions
- With the evidence of progress achieved by current reintroduction programs, the tribes will advocate for additional financial support for program infrastructure, operation and monitoring.
- The tribes will continue to seek funding for establishment of the following new reintroduction programs.
- Grande Ronde River coho
- Wallowa Lake/River (Grande Ronde River) sockeye
- Keechelus Lake, Kachess Lake and Bumping Lake (Yakima River) sockeye
- The tribes, in appropriate coordination with other Columbia Basin tribes and First Nations, will investigate options for reintroducing salmon and lamprey above Grand Coulee, Dworshak and the Hells Canyon Complex dams. See the recommendations, Restoring Fish Passage and the Columbia River Treaty.