Are Recent Increases in Columbia Basin Natural-origin Steelhead Adult Return Abundance a Response to Restoration Actions?
Actions to improve freshwater habitat quantity and quality are widely recognized as essential to recovering Columbia Basin salmon populations listed under the Endangered Species Act. Efforts to quantify the effectiveness of these actions in improving salmon abundance and productivity are increasing, but still rare. A number of agencies and organizations have been collaborating to recover threatened steelhead populations in many tributaries upstream of Bonneville Dam with many hundreds of reach-specific habitat actions implemented regionally over the past 15-25 years. We analyzed estimated adult steelhead return abundance datasets for several of these streams dating back to the mid-1980s. An increase in adult steelhead return abundance is apparent in all streams for the most recent seven return years when compared to prior years. However, the proportionate increase is more pronounced in some tributaries relative to others. The proportionate increase is especially pronounced in the Yakima River Basin where steelhead kelt reconditioning (short-term artificial rearing of post-spawned fish for the purpose of sexual rematuration and repeat spawning) is being combined with habitat actions to achieve restoration goals. This talk is intended to be a technical dialogue discussing whether we may be seeing an adult fish response to concerted regional efforts to improve habitats and fish runs and to solicit input on where to take this analysis from here..
Bosch, W. 2017. Are recent increases in Columbia Basin natural-origin steelhead adult return abundance a response to restoration actions? Oregon Chapter of the American Fishery Society Annual Meeting, Bend, OR, February 28-March 3, 2017.