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Evaluating Climate-induced Runoff and Temperature Change on Stream Habitat Metrics for Endangered or Threatened Fish

Project ID: 6507
Principal Investigator: Jennifer Bountry
Research Topic: Ecosystem Needs
Priority Area Assignments: 2011 (Climate Change and Variability Research), 2012 (Climate Change and Variability Research), 2013 (Climate Change and Variability Research)
Funded Fiscal Years: 2011, 2012 and 2013
Keywords: None

Research Question

We propose to address the following research questions:

1. How will climate change alter the hydrologic runoff and water temperature inputs to stream and flood plain reaches used by endangered or threatened fish species?

2. How are runoff and temperature changes linked to fish habitat within a stream reach?

This research is in response to the Science and Technology fiscal year 2011 call for climate change research needs Topic 4, "Assess Natural Systems Response to Climate Change: Ecosystems category." The two subcategories this research will address are: "Model frameworks for assessing climate change responses for fisheries, non-native riparian vegetation," and "other species or habitat conditions; and understanding on how source water quality characteristics, specifically water temperature, depend on climatic variables, and how dependencies may evolve in a changing climate."

Need and Benefit

Stream rehabilitation projects have been ongoing under numerous programs for many years. Despite decades of rehabilitation through hydro and habitat actions, salmonid populations have declined to levels that warrant listing under the Endangered Species Act (ESA). Rehabilitation actions implemented are often engineering based and aim at altering channel hydraulics and form to provide appropriate velocities, depth, and sediment sizes known to be preferred by the fish species of interest. Therefore, implementers may be confident that selected actions will increase the quantity of available habitat from a physical perspective. However, it is generally not clear if actions have an impact on improving the quality of the habitat, if the habitat generated is sustainable over the long term, and whether it will ultimately be used by fish. Salmonids, in particular, require adequate availability of food, but linkages between altered hydraulics and the food web are almost never evaluated, even though it could cause a failure to meet the basic rehabilitation objectives. To further complicate matters, climate change has become an increasing concern in ESA salmon programs because many streams are already believed to be at an upper threshold of tolerable water temperatures during low-flow, later summer, and fall periods.

It is proposed that, in addition to physical habitat suitability, critical linkages exist for fish growth and survival related to watershed and river-scale processes such as hydraulic residence time, fluctuation in flood plain and side channel inundation, and water temperature. These linkages are directly related to the flow runoff and water temperature, which, in turn, are impacted by climate change. Research is needed to develop a set of linked models to help predict the short- and long-term effects of climate change and resource management actions on river processes. This type of model framework would be useful for planning and evaluating habitat improvement projects for ESA-listed salmonids in the context of anticipated global climate change. The model framework will add the capability of linking watershed and reach-scale numerical models with biological models that will predict age-specific and life-stage specific fish production based on habitat and food availability. The models will help the Bureau of Reclamation and its partners develop river rehabilitation projects that will improve conditions for listed salmonids with consideration for habitat response to climate change.

Contributing Partners

None

Research Products

Independent Peer Review

The following documents were reviewed by qualified Bureau of Reclamation employees. The findings were determined to be achieved using valid means.

Thermal Profiles for Selected River Reaches of the Methow and Chewuch Rivers, Washington, August 2011 (interim, PDF, 601KB)
By Mr. Andrew Gendasz
Report completed on March 27, 2012

Longitudinal profiles of near-streambed and near-surface temperatures were collected for selected reaches of the Methow and Chewuch Rivers, Washington, during August 2011 to facilitate development of a stream temperature model near the confluence of the Methow and Chewuch Rivers. Temperature was measured using a probe with an internal datalogger towed behind a watercraft moving downstream at ambient river velocity.
Keywords: water temperature, methow

This information was last updated on October 21, 2014
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