Our goal is to compare 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 contribute to the recovery of naturally spawning populations while minimizing genetic and ecological risks is unknown.

This project will compare 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 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.

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. 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.  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. NOR and HOR upstream migrating adults will continue to be genotyped so we can focus on parentage assignment for adults.  

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.  This project year, juvenile steelhead production and adult returns occurring within Abernathy Creek will be compared to two control streams (i.e. Germany and Mill creeks).  In addition, we are evaluating hatchery rearing methods and their impacts on behavior, physiology, and gene expression of HOR steelhead. We continue to assess demographic changes and differences in behavior and physiology between NOR and HOR steelhead to evaluate the impact of 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.  Comparing 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. This objective will not be worked on in 2018.
Objective  8. Manage and administer project and communicate work and results to BPA and the scientific community.
There was a 9th Objective to be completed by WA Department of Fish and Wildlife. No more effort will be expended on that Objective.

PROJECT CLOSURE
This project will end in three years, and project years 2018, 2019, 2020 will be dedicated to gathering data from the last few returning adult steelhead and reporting. The soft closing of this project will allow irretrievable, unique information to be collected from brood year 2017 juveniles as well as brood year 2015, 2016, and 2017 returning adults and specific objectives such as evaluating genetic change to be met. In 2018, a study of juvenile fish fed low fat vs. typical diets and a comparison of gene expression of the two groups will be completed, adult brood year 2015 hatchery steelhead will be removed from Abernathy Creek, and natural origin steelhead will be passed upstream. Appropriate data and samples will be collected from the juveniles and adults. Subsequent years (2019 and 2020) will only require removing adult hatchery steelhead from Abernathy Creek and passing natural origin steelhead upstream after collecting data and samples. All three years will include staff time to analyze data, write reports, and publish peer reviewed papers. In summary, the soft closing of this project will:
• Allow us to finish important genetics and nutritional studies that may help to explain why hatchery origin fish may have lower relative reproductive success
• Prevent the investment in rearing steelhead from being wasted
• Allow return data for all Abernathy Creek hatchery origin adult steelhead to be collected
• Prevent steelhead smolts from being euthanized
• Prevent returning hatchery adult steelhead from having uncontrolled access to the upper Abernathy Creek watershed
• Allow important results about conservation hatcheries and interactions between wild and hatchery steelhead to be finalized and disseminated via reports and publications