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  • Assessing the efficacy of acclimation sites and habitat quality and quantity for supplementation success: tradeoffs between homing and spawning site selection.


Northwest Fisheries Science Center (NWFSC) Environmental and Fisheries Sciences EFS - Environmental Physiology


Efficacy of acclimation sites
Assessing the efficacy of acclimation sites and habitat quality and quantity for supplementation success: tradeoffs between homing and spawning site selection.
The Federal Columbia River Power Supply (FCRPS) Biological Opinion (BiOp) calls for studies that estimate ecological and genetic impacts of hatchery fish on wild populations, and evaluate the effectiveness of hatchery supplementation measures to reduce potentially harmful effects of artificial production to aid recovery through hatchery reform. The FCRPS BiOp further explicitly calls for studies that examine the appropriate role of supplementation and the relationship between supplementation and habitat actions in salmon recovery. A basic premise of supplementation is that artificially produced fish will help develop self-sustaining spawning populations both by increasing current natural production and reestablishing populations in underutilized and recovered habitats.

One hatchery reform measure that has been incorporated into many supplementation programs throughout the Columbia River Basin is the use of satellite acclimation facilities to repopulate underutilized habitat. However, the efficacy of these facilities in re-establishing naturally spawning populations and minimizing negative interactions between wild spawners and supplemented fish has not been established. Our studies have involved comprehensive carcass and redd mapping surveys and radio telemetry to examine the role of acclimation sites in homing and spawning of spring Chinook salmon released as part of the Yakima/Klickitat Fisheries Project (YKFP) supplementation program. In addition, we are examining the complex linkages between habitat quality and spawning site selection in supplemented Columbia River populations. These studies involve mapping and assessing habitat distribution and quality relative to supplementation rearing and release facilities, and coupling these findings to ongoing analysis of homing and spawning patterns. Our results have provided unique insights into the process of homing, straying, and spawning site selection, interactions and success of hatchery and wild spawners, and the efficacy of supplementation and acclimation sites in salmon recovery.

These studies will help identify appropriate locations for recovery-related supplementation rearing and release facilities (acclimation sites), and ultimately allow us to develop scenario models predicting the spatial distribution of spawning relative to proposed supplementation facilities and available habitat (including future habitat restoration sites). The work is being conducted by Northwest Fisheries Science Center (NWFSC) scientists collaborating with the University of Washington, Yakima Nation, U.S. Geological Survey (USGS), and the Washington Department of Fish and Wildlife (WDFW). Products for this project include annual reports, peer-reviewed publications, presentation of results at local and national meetings, and consultation with the Northwest Regional Office (NWR) and supplementation managers.

Research Themes

Habitats to support sustainable fisheries and recovered populations
Healthy oceans, coastal waters, and riverine habitats provide the foundation for aquatic resources used by a diversity of species and society. Protecting marine, estuarine and freshwater ecosystems that support these species relies on science to link habitat condition/processes and the biological effects of restoration actions. The NWFSC provides the habitat science behind many management actions taken by NOAA Fisheries and other natural resource agencies to protect and recover aquatic ecosystems and living marine resources. The NWFSC also maintains a longstanding focus on toxic chemical contaminants, as a foundation for regional and national research on pollution threats to fisheries and protected resources.
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 effective and efficient habitat restoration and conservation techniques
Maintaining and re-establishing viability and sustainability of living marine resources requires conservation and rehabilitation or restoration of habitats upon which species depend. Common habitat restoration approaches and tech-niques often presume that habitats are static features of the environment, and that creation of stable habitats is a desirable restoration strategy. However, riverine, nearshore, and marine habitats are created and sustained by dynamic landscape, climatic, and oceanographic processes and biota are adapted to changing habitats that are within the range of natural variability. Hence, current restoration strategies often have limited success, in part because they fail to recognize larger scale processes that drive habitat change, and in part because they fail to recognize intrinsic habitat potential of individual restoration sites. The main goals of this research focus are to: improve understanding of how large-scale processes create diverse and dynamic habitats that support marine and anadromous species, better understand how human activities alter habitat-forming processes and habitats, develop new restoration techniques that are compatible with sustainable habitat-forming processes, and understand the variety of actions needed to adequately conserve intact critical habitats. In addition, NWFSC’s research will improve understanding of how new and existing habitat restoration and protection techniques affect fish and habitat at multiple scales (i.e., reach, watershed, Evolutionarily Significant Unit).
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.


Chinook salmon
species of interest
Columbia River
Columbia River
Endangered Species Act
research to guide listed species recovery
Oncorhynchus mykiss
Wenatchee River Basin
interior Columbia River Basin subwatershed
research technique
artificial propagation
research technique
climate change
changes in climate
coho salmon
Oncorhynchus kisutch
conservation hatcheries
captive broodstock technology
habitat assessment
methods to improve habitat assessment
research focus
landscape ecology
study of the effect of patterns on processes and vice versa
recolonization dynamics of salmon following reintroduction
process of establishing a species in an area it once occupied but currently does not
spawning site selection
research focus
research focus
research focus


None associated


Species Oncorhynchus kisutch
Coho salmon, silver salmon
Species Oncorhynchus mykiss
rainbow trout, steelhead trout, syeelhead trout
Species Oncorhynchus tshawytscha
Chinook salmon, king salmon, spring salmon


Andrew Dittman
Principal Investigator
Darran May
Donald Larsen
George Pess
Internal Collaborator
Mary Moser
Paul Hoppe
Steve Corbett