Abstract: Session A 8:30 am (Back to Session A)
Integrating the Stream Sciences to Predict Aquatic Population Response
Ashley Ficke, PhD
Lucas Babbitt, PE, CFM
While the effects of stream restoration on aquatic habitat can be estimated and subsequently measured, the effects of stream restoration projects on aquatic life remain largely unclear. This presentation will review three projects with specific habitat and population uplift requirements that were designed using an integration of the stream sciences to predict habitat and population response associated with the proposed restoration approaches.
Improving in-stream habitat for impaired systems requires the integration of all the stream sciences by making physical modifications within naturally occurring ranges of values, which varies by geography. In headwater systems habitat limitations are typically associated with lack of organic matter, nutrient retention, and holding water; in foothills systems habitat limitations are typically associated with lack of temporary foraging and spawning habitat and lack of refuge from unstable ice conditions; and in plains systems habitat limitations are typically associated with lack of bedform diversity and presence of features that benefit invasive species.
Designing stream restoration projects to target a specific habitat and population response requires careful assessment and hypothesis testing. For this presentation we will review three projects that were evaluated with several methods to predict habitat response, which ranged from visual assessments focused on specific metrics (such as residual pool depth) to development and query of 2-dimensional hydraulic modeling data for the entire project reach. We have developed a design process that is founded on integrating biologic, geomorphic, and hydraulic data to solicit a specific habitat and population response and are in the early stages of post-construction monitoring to test our hypotheses.e fall of 2019 into spring of 2020.