• Projects
  • Genetic Basis of Migratory Tendency and Life History Plasticity in Oncorhynchus mykiss


Northwest Fisheries Science Center (NWFSC) Conservation Biology CB - Genetics and Evolution


Steelhead Life History and Migration
Genetic Basis of Migratory Tendency and Life History Plasticity in Oncorhynchus mykiss
Steelhead population abundance is depressed throughout much of its southern range, and several Distinct Population Segments (DPSs) are listed as threatened or endangered under the US Endangered Species Act (ESA). Some anadromous populations are associated with relatively large resident trout populations, and some of these resident populations can produce migrating smolts. We are trying to determine the genetic architecture, population history, and plasticity of anadromy and residency in this species, with the intent of determining whether the hybrid migratory strategy expressed in wild populations like this is key to maintaining long-term resilience and productivity of anadromous populations. This collection of NWFSC Genetics and Evolution Program studies represents a long-term collaboration between NWFSC and the Alaska Fisheries Science Center, the Southwest Fisheries Science Center, the National Park Service, the US Forest Service, the Lower Elwha Klallam Tribe, and the US Geological Survey to understand the intrinsic (biological, genetic) and extrinsic (environmental) factors that influence production, diversity, and variation in these characteristics in wild steelhead and the resident trout they interact with. It involves annual fieldwork to collect data on juvenile and adult fish and reconstruct their molecular pedigrees and conduct quantitative genetic analyses, as well as to assess temporal trends in abundance and productivity and the condition of their freshwater habitats.

Research Themes

Recovery and rebuilding of marine and coastal species
The Pacific Northwest is home to several iconic endangered species, including Pacific salmon and killer whales, and several rockfish species. Mandates such as the Endangered Species Act, MagnusonStevens Act, and the Marine Mammal Protection Act, grant NOAA Fisheries the authority to manage the recovery of depleted species and stocks. The NWFSC contributes to species recovery through research, monitoring and analysis, providing NOAA managers and regional stakeholders the tools and information they need to craft effective regulations and develop sustainable plans for recovery.

Research Foci

Characterize the population biology of species, and develop and improve methods for predicting the status of populations
To evaluate species status and recovery, it is necessary to understand key aspects of the population biology of the species in question. This includes basic information on abundance, age structure, recruitment, spatial distribution, life history and how the species interacts with its ecosystem. For some recovering species, including most overfished groundfish stocks, many ESA-listed Pacific salmon stocks, and high profile species such as Southern Resident killer whales, this basic information is often reasonably well understood. For other recovering species, such as Pacific eulachon and some ESA-listed rockfish species, even basic information (e.g. stock abundance) is unknown. Even for well-studied species, key information on survival rates for critical life stages and how the environment affects these vital rates is lacking. Without basic information on species dynamics, achieving other goals such as quantifying relationships between human activities and species recovery or even knowing if species recovery goals are being met will not be successful. The NWFSC, in partnership with regional stakeholders, including states, tribes and industry, is conducting research to collect and monitor critical demographic information for recovering species.
Describe the relationships between human activities and species recovery, rebuilding and sustainability
Human activities play a major role in determining the status of species and stocks. Rebuilding and recovery therefore need to address how these activities affect their status. At the NWFSC, biophysical modeling is used to link specific human activities such as land use and pollution to habitat conditions, and then to link these conditions and other activities to particular life stages. These models can be used to quantitatively assess how human activities influence species abundance, productivity, distribution and diversity. Not surprisingly, altering human activities in some way is often necessary for species or stock recovery and rebuilding. It is therefore important to understand the socio-economic effects of alternative management structures. Gathering data on their economic costs and social impacts helps identify actions that are cost-effective. These actions will need to be resilient to potential changes in climate throughout the region. Research on how humans react to management strategies helps policy makers avoid those that lead to unintended consequences that can hinder rather than help recovery.
Develop methods to use physiological, biological and behavioral information to predict population-level processes
Understanding the biological processes occurring within organisms is a powerful way of understanding how environmental changes affect those organisms. Genetics, developmental, physiological and behavioral studies all provide important information for effective species recovery and rebuilding. Integrating this information into models is vital to predict how populations will respond to natural or human perturbations, and to assess the constraints to stock rebuilding efforts. For example, data on thermal tolerance and physiological responses to temperature can be used to explore changes caused by shifts in climate on reproductive behavior and productivity, viability, movement, habitat selection, and population dynamics. Similarly, data on contaminants that impact physiological processes (immune system, growth, development, reproduction, and general health) are critical in determining how these compounds affect population dynamics. Data on biological responses of organisms to ocean acidification are useful for understanding how acidification may affect individual development and survival. The NWFSC collects such information for several species that are of concern, targets of fisheries or otherwise important for overall ecosystem function. NWFSC scientists will continue to expand current efforts and develop methods to incorporate physiological, biological and behavioral data into population models in order to predict population-level processes from these individual level data.
Evaluate the effects of artificial propagation on recovery, rebuilding and sustainability of marine and anadromous species
Artificial propagation has the potential to provide benefits both to species recovery and to seafood sustainability. Artificial propagation also poses risks to wild species and ecosystems. In the past, the use of artificial propagation has been an important risk factor for several threatened and endangered species, particularly Pacific salmon. Assessing the effects of artificial propagation is complicated by the fact that programs vary widely in size, rearing practices, and goals. The NWFSC conducts critical research on the influence of artificial propagation on population dynamics, growth rate, ecology of infectious disease, and the evolutionary fitness of wild fish and other marine organisms. Results of this research are needed to support the recovery of fish populations and have been especially valuable in providing critical information for recent, larger scale habitat restoration activities such as the Elwha Dam removal. NWFSC will continue to conduct science that informs the discussion about whether to allow fish to recolonize naturally after barrier removal, or to supplement populations with hatchery fish and on the impacts of aquaculture on fishing pressure and practices, and on the surrounding environment and ecosystem.


pedigree reconstruction
population viability analysis
quantitative genetics
Oncorhynchus mykiss




Species Oncorhynchus mykiss
rainbow trout, steelhead trout, syeelhead trout


Abigail Wells
David Kuligowski
Eric LaHood
Gary Winans
George Pess
Internal Collaborator
Giles Goetz
Jeff Hard
Krista Nichols
Principal Investigator