INTRODUCTION

In 1999, the National Marine Fisheries Service (NMFS) issued, in support of the U.S. Endangered Species Act (ESA), a Biological Opinion on artificial Propagation in the Columbia River Basin.  In that biological opinion, NMFS concluded that non-native hatchery stocks of steelhead jeopardize the continued existence of ESA-listed, natural spawning populations of steelhead in the Columbia River Basin.  NMFS recommended-as a reasonable and prudent alternative (RPA)-that federal and state agencies phase out non-native broodstocks of steelhead and replace them with native broodstocks.  However, NMFS provided no guidance regarding how to achieve that RPA.
  
The development of native broodstocks of hatchery steelhead by traditional methods of trapping upstream migrating adults may pose unacceptable biological risks to naturally spawning populations, particularly those that are already listed as threatened or endangered under the ESA.  Trapping adult steelhead may be logistically unfeasible in many subbasins because of high water flows in the spring, when steelhead migrate upstream to spawn.  Additional risks associated with trapping adults include genetic founder effects and difficulties meeting minimum, genetic effective number of breeders from a relatively small number of trapped adults and initial spawners.  As a result, alternative methods for developing native broodstocks are highly desired.

Rearing wild-caught juveniles to sexual maturity in captivity offers many potential advantages over trapping natural-origin adults including (a) much reduced demographic impacts to natural populations and (b) substantially greater genetic diversity for the founding broodstock relative to the small number of natural-origin adults that would otherwise be trapped to start a broodstock (Ryman and Laikre 1991; Ryman et al. 1995).  The Abernathy Fish Technology Center (AFTC) is investigating the feasibility of this latter approach by developing a research hatchery program for steelhead on Abernathy Creek, WA, a tributary to the lower Columbia River.  This research program provides an excellent opportunity to assess the genetic, ecological, and fitness effects of artificial propagation on the genetic constitution of hatchery-produced fish and naturally-spawning populations with which hatchery-origin fish may spawn.

The overall goal of the project described here is to determine the natural reproductive success and mean relative fitness of hatchery-origin (HOR) and natural-origin (NOR) steelhead in Abernathy Creek, WA, and to assess the overall demographic effects of hatchery fish supplementation in Abernathy Creek relative to two adjacent control streams, Germany and Mill Creeks. This work responds directly to the FCRPS , RPA Action No. 182 .  This work was first approved for funding by the Bonneville Power Administration in fiscal year (FY) 2004.

Objective 1-Develop a "native" or "endemic" hatchery broodstock of steelhead by producing hatchery-origin (HOR) progeny of natural-origin (NOR) captively-reared adults from Abernathy Creek.

Objective 2-Estimate total annual smolt out migration of steelhead, coho salmon, and cutthroat trout in Abernathy, Germany, and Mill Creeks.

Objective 3-Assess physiological status of HOR and NOR steelhead smolts out-migrating from Abernathy Creek.

Objective 4-Monitor and evaluate potential residualism, behavioral displacement, and ecological interactions (competition, predation) between yearling HOR steelhead released from the AFTC and NOR salmonids in Abernathy Creek.

Objective 5-Use selectively-neutral, DNA markers to determine the amount of genetic change associated with captive rearing of wild-caught NOR steelhead, spawning, and subsequent hatchery rearing of their progeny prior to release as yearlings.

Objective 6-Monitor upstream migration and adult returns of steelhead, coho salmon, and cutthroat trout past the AFTC in Abernathy Creek.

Objective 7- Trap and spawn returning HOR and NOR adult steelhead for broodstock to produce F2 BY2005 HOR progeny for release into Abernathy Creek as yearlings in 2006.

Objective 8-Determine the relative, natural reproductive success of hatchery-origin and natural-origin steelhead in Abernathy Creek upstream of AFTC.

Objective 9-Communicate work and results to BPA and the scientific community.  

REFERENCES

Ryman, N., Jorde, P. E., and Laikre, L.  1995.  Supportive breeding and variance effective population size. Conservation Biology 9:1619-1628.

Ryman, N., and Laikre, L  1991.  Effects of supportive breeding on the genetically effective population size.  Conservation Biology 5:325-329.