Our goal is to determine the relative reproductive success of hatchery-origin and natural-origin steelhead and assess the demographic effects of hatchery fish supplementation in Abernathy Creek relative to two control streams. Currently the ability of hatchery-origin steelhead to reproduce successfully and contribute to the recovery of naturally spawning populations while minimizing genetic and ecological risks is unknown.

This project will evaluate relative reproductive success between hatchery-origin (HOR) and natural-origin (NOR) steelhead trout, simultaneously investigating methods of operating a conservation hatchery and the effectiveness of artificial production of an integrated NOR/HOR broodstock on recovery. This directly addresses 2008 NOAA Fisheries FCRPS Biological Opinion (NWF v. NMFS, Civ. No. CV 01-640-RE (D. Oregon)) reasonable and prudent alternatives (RPAs) 63.1, 64.1, and 64.2. The ability of HOR adults to reproduce successfully and contribute, via supplementation, to the recovery of naturally spawning steelhead populations is still a major uncertainty in the Pacific Northwest. This question has been debated intensively throughout the Columbia River Basin for over 10 years but remains unresolved. Additionally, the source of broodstock for supplementation programs may have negative genetic and ecological impacts on natural populations. The development of native broodstocks of hatchery steelhead may pose unacceptable biological risks to naturally spawning populations that are listed as threatened or endangered under the Endangered Species Act (ESA). The traditional method of initiating new hatchery broodstock of anadromous salmonids is to trap adults during their spawning migration. However, removing NOR adults from ESA listed populations may not be biologically acceptable because such activities may further depress those populations. Also, trapping large numbers of adult steelhead may not be feasible in many subbasins because high water in the spring during steelhead migrations often destroys temporary weirs. As a result, alternative methods for developing broodstocks from NOR steelhead are highly desired.

This project provides an assessment of an alternative method of establishing a native salmonid broodstock when large numbers of native adults are unavailable, a common issue for the establishment of conservation hatcheries. Abernathy Fish Technology Center (AFTC) developed an integrated NOR/HOR steelhead broodstock starting with pre-smolt NOR juveniles collected from Abernathy Creek that were reared to sexual maturity in a hatchery. Broodstock programs developed through juvenile collections have the advantage of increasing the genetic effective population size by potentially incorporating the offspring of all adults that spawn successfully within a stream or watershed.  In turn, greater genetic effective population size of the hatchery stock reduces the risk of genetically “swamping” the natural spawning population with a few over-represented families. In order to minimize genetic differences between NOR and HOR steelhead, we will continue to utilize captured NOR steelhead to maintain an integrated NOR/HOR broodstock. To achieve our goal of evaluating relative reproductive success, all NOR and HOR upstream-migrating adults will continue to be genotyped and samples of their NOR offspring will be identified via parentage analyses.

While our results to date comparing the relative reproductive success within Abernathy Creek are based on parentage assignment for juveniles, continuation of this work will provide the opportunity to compare the adult to smolt relative reproductive success of HOR and NOR parents to adult to adult reproductive success.  Our renewed focus on strict adherence to spawning protocols will allow us to assess our ability to maintain genetic similarity between the HOR and NOR components of the Abernathy Creek steelhead population and correct the effects of previously using a small proportion of NOR broodstock in the hatchery.  Beginning this project year, we are also increasing our efforts to control access of ungenotyped adults above the AFTC weir and to collect a larger proportion of the NOR offspring.  Genetic effects in addition to juvenile steelhead production and adult returns occurring within Abernathy Creek will be compared to two control streams (i.e. Germany and Mill creeks).  New this project year in response to a recommendation by the Independent Scientific Review Group will be a validation carried out in Abernathy Creek of redd survey counts that are used to estimate adult returns (Objective 9, to be completed under contract with Washington Department of Fish and Wildlife).  Additionally, we are assessing demographic changes and behavioral and physiological differences between HOR and NOR steelhead to evaluate the supplementation program.  Assignment of adult progeny will also allow us to assess correlations in biological characteristics (e.g. physiological traits, run timing, return size and age) between parents and returning adult offspring.  Determining the relative reproductive success of individual HOR and NOR adults coupled with monitoring demographic changes in population abundance along with behavioral and physiological differences, with appropriate natural population controls, is critical to assessment of artificial production in conservation hatcheries.


OBJECTIVES
Objective  1. Maintain a conservation hatchery broodstock of steelhead using protocols to minimize effects of artificial rearing on an integrated broodstock.
Objective  2. Use selectively-neutral, DNA markers to determine the amount of genetic change associated with captive rearing of NOR steelhead.
Objective  3. Estimate total annual smolt emigration and behavior of steelhead in Abernathy, Germany, and Mill creeks.
Objective  4. Assess physiological status of HOR and NOR steelhead smolts.
Objective  5. Control passage of HOR and NOR for evaluation of relative reproductive success; retain some steelhead for conservation hatchery broodstock.
Objective  6. Develop conservation hatchery broodstock of steelhead that is genetically integrated.
Objective  7. Determine the relative, natural reproductive success of hatchery-origin (HOR) and natural-origin (NOR) steelhead in Abernathy Creek above Abernathy Fish Technology Center.
Objective  8. Manage and administer project and communicate work and results to BPA and the scientific community.
Objective  9. Validate steelhead redd count surveys.