BridgeCreekLocation

Project Contacts:

Nick Bouwes, EcoLogical Research
Chris Jordan, Northwest Fisheries Science Center, NOAA-Fisheries
Michael Pollock, Northwest Fisheries Science Center, NOAA-Fisheries
Carol Volk, South Fork Research
Joe Wheaton, Utah State University

Key Management Question 3

Bridge Creek is listed as one of 11 tributary Major Spawning Areas critical to the recovery of the Lower John Day mid-Columbia steelhead population and has high restoration potential.  Habitat factors limiting steelhead productivity on Bridge Creek include an overall lack of habitat diversity, low summer flows, and high stream temperatures.

Beaver Dam Analogs (BDAs) are being installed to mimic and encourage dam building activities of beaver.  Phase I of treatment installments occurred in 2009 and post-restoration monitoring has shown improvements in in-channel condition and the productivity of steelhead.

Status: In Progress

BridgeTimeline_20160209

Finding and Uses

Initial findings from Bridge Creek show that the installation of Beaver Dam Analogs (BDAs) increased juvenile steelhead density, survival, and production in incised streams.

This novel and relatively inexpensive restoration approach could greatly improve the habitat of listed salmon and steelhead in the enormous number of miles of streams experiencing incision (or other forms of habitat degradation) in the Columbia River Basin.

Figure 2

Summary of intervention analyses. On every sampling occasion, the control is subtracted (difference) or divided into (ratio) the treatment value. Next, the average difference pre-manipulation is subtracted or divided into the post-manipulation value. Confidence intervals (90%) not overlapping zero for difference and 1 for ratio indicates significance at a = 0.1. Comparisons are made between Bridge Creek (treatment) and Murderers Creek (control), respectively. Results for difference in density (no./100m) and average growth (g/fish/120days), and ratio of survival (proportion surviving over 120 days) and production (total g/100m/120days) estimated as density*growth*survival are displayed.

Expected changes following the installation of beaver dam analogs (BDAs). Beaver dams and BDAs slow and increase the surface height of water upstream of the dam. The ponds and plunge pools that form above and below the dams, respectively, make the shape and composition of the stream bottom more complex, which provides resting and efficient foraging opportunities for juvenile fish.

The number of dams (natural beaver dams and BDAs) through time.

The number of dams (natural beaver dams and BDAs) through time.

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