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Restoration Ecology 2011 Bradley Buckallew
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Anadromous Born and spend juvenile life in freshwater Venture out into ocean to spend their adult lives Return to freshwater to spawn Die after spawning Figure 1. Pacific Salmon species (http://www.epa.gov/wed/pages/staff/lac key/pubs/illusion.htm)
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Severe decline in numbers over the past century ( Gresh et al 2000 ) Historic Biomass in Pacific NW 160-226 million kg Present Biomass in Pacific NW 11.8-13.7 million kg Figure 2. Estimated spawning escapements for the Central Valley spring run of chinook salmon (Yoshiyama et al 1998)
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Keystone Species Provide important food source for predators and scavengers Carcasses provide nutrient boost to aquatic and terrestrial ecosystems Interaction between salmon and bear may provide up to 24% of riparian N budgets (Helfield et al 2006) Higher juvenile coho salmon densities and body weights in creeks with salmon carcasses (Bilby et al 1998) Current amount of nitrogen and phosphorus deposited through salmon is 6-7% of historical levels (Gresh et al 2000)
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Connect habitats that are blocked by barriers such as roads and dams Out of a variety of techniques, 72% of the increase in chinook salmon juveniles was due to barrier removal (Scully et al 1990) Year after the removal of fish barrier, 90% of adult coho salmon spawned above the barrier’s previous location (Beamer et al 1998)
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Often used due to their low cost compared to bridges Problems associated with culverts Juvenile fish cannot pass through due to increased water velocity Limit downstream movement of sediment, woody debris and organic materials Reduce upstream nutrient levels by restricting adult movement Of 77 culverts that were new or repaired in the past thirteen years in Washington, 30% were found to actually be fish barriers (Price et al 2010)
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Table 1. Summary of various stream crossing structures (Roni et al 2002)
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Log structures, bolder jams, debris jams, log weirs, etc. Juvenile coho salmon densities were 1.8 to 3.2 times higher in areas were artificial large woody debris was placed (Roni et al 2001) The placement of rock-filled gabions and boulder structures lead to a 2.5 increase in coho salmon spawners with 50% of the salmon spawning on the newly deposited gravel trapped by gabions (House 1996)
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Not a long term solution due to structure degradation Within 10 years, erosion to gabions caused a reduction in created habitat and loss of accumulated spawning gravel (House 1996) The median failure rate and median damage rate of 161 artificial structures in Oregon and Washington, with a maximum age of 5 years, were 18.5% and 60% respectively Figure 3. Failure and impairment rates of structures classified by design (Frissell and Nawa 1992)
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Focus on restoring hydrologic, geologic and riparian processes Flood regime Floodplain connectivity Sediment delivery Removal of adverse conditions Figure 4. Linkages between landscape controls, habitat-forming processes and habitat conditions (Roni et al 2002)
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Converting 70 miles of the river back to its natural, free flowing state Removing two dams and draining their respective reservoirs Reestablishing native salmon and vegetative species Figure 5. Elwha River (Scott Church http://www.nps.gov/olym/naturescienc e/elwha-faq.htm)
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Beamer, E., T. Beechie, and J. Klochak. 1998. A strategy for implementation, effectiveness, and validation monitoring of habitat restoration projects, with two examples from the Skagit River basin, Washington. Completion report (Cost Share Agreement CCS- 94-04-05-01-050) to U.S. Forest Service, Sedro Woolley, Washington. Bilby, R., Fransen, B., Bisson, P. and Walter, J. 1998. Response of juvenile coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss) to the addition of salmon carcasses to two streams in southwestern Washington, USA. Can. J. Fish. Aquat. Sci. 55: 1909-1918 Frissell, C. and Nawa, R. 1992. Incidence and Causes of Physical Failure of Artificial Habitat Structures in Streams of Western Oregon and Washington. North American Journal of Fisheries Management 12: 182-197 Gresh, T., Lichatowich, J. and Schoonmaker, P. 2000. An Estimation of Historic and Current Levels of Salmon Production in the Northeast Pacific Ecosystem: Evidence of a Nutrient Deficit in the Freshwater Systems of the Pacific Northwest. Fisheries 25: 1, 15–21 Helfield, J. and Naiman, R. 2006. Keystone Interactions: Salmon and Bear in Riparian Forests of Alaska. Ecosystems 9: 167-180 House, R. 1996. An Evaluation of Stream Restoration Structures in a Coastal Oregon Stream, 1981-1993. North American Journal of Fisheries Management. 16: 2, 272–281 Price, D., Quinn, T. and Barnard, R. 2010. Fish Passage Effectiveness of Recently Constructed Road Crossing Culverts in the Puget Sound Region of Washington State. North American Journal of Fisheries Management. 30: 5, 1110—1125 Roni, P., Beechie, T., Bilby, R., Leonetti, F., Pollock, M. and Pess, G. 2002. A Review of Stream Restoration Techniques and a Hierarchical Strategy for Prioritizing Restoration in Pacific Northwest watersheds. North American Journal of Fisheries Management 22: 1, 1–20 Roni, P. and Quinn, T. 2001. Density and size of juvenile salmonids in response to placement of large woody debris in western Oregon and Washington streams. Can. J. Fish. Aquat. Sci. 58: 282-292 Yoshiyama, R., Fisher, F. and Moyle, P. 1998. Historical Abundance and Decline of Chinook Salmon in the Central Valley Region of California. North American Journal of Fisheries Management. 18: 3, 487—521
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