1134596 (Tullos). This research will document the hydraulic interactions between two Engineered Log Jam (ELJ) architectures and a river's flow patterns and intensity, leading to better understanding on how ELJ characteristics influence the locations and magnitude of forces and energy loss. The results will advance existing research on fish ecology by making direct observation of fish behavior using new visually-based approaches, by linking bioenergetics to the hydraulic environment, and by improving understanding of how fish perceive the ecological benefits of ELJs. This work will develop a novel dataset by employing state-of-the-art techniques for observing fish and fluids and will apply innovative analytical techniques for extracting detailed information on fish behavior and hydraulic structure, scale, and intensity. This interdisciplinary collaboration is supported by experience in river engineering and restoration, aquatic ecology, fish behavior, experimental- and field-study design and measurements, and quantitative data analysis, as well as by existing research facilities and resources. The research targets (a) restoration practitioners designing log jams, and (b) students at the high school, undergraduate, and graduate level. Targeting practitioners, a video on fish use of ELJs will be developed and applied concepts (e.g. drag coefficients, force distributions around structures) relevant to the design of ELJs will be investigated. This project will give students at the high school, undergraduate, and graduate level the opportunity to participate in a multi-disciplinary research environment and to receive training in advanced methods for observations of hydraulics and fish in rivers.

Project Report

Summary Re-introduction of large wood for expanding hydraulic variability is an increasingly common practice, yet it is not yet known what elements of hydraulic variability are most beneficial to fish. To begin investigating the use and benefit of flow field variability around wood for juvenile coho, we conducted a mensurative, 1:1 scale experiment in outdoor stream channels with high-resolution observations of the three-dimensional velocities and fish locations around a full-channel log jam. Intellectual Merit The coupling of very high-resolution observations of the flow field and fish locations around large wood into a well-documented database is a unique and important contribution of this project. This project also generated protocols for applying the emerging techniques applied in collecting these data. These data were analyzed within the course of this project to investigated questions around: 1) the bioenergetic benefits of wood for minimizing the energy expenditure of juvenile coho in winter, 2) how increasing the resolution of flow field observations impacts estimates of energy expenditure and apparent habitat selection, and 3) detailed and high-resolution observations, modeling, and characterizations of the impacts of large wood on the flow field. Given the richness of this dataset, we anticipate that it will continue to produce compelling and management-relevant papers for years to come. Broader Impacts The research investigated management-relevant results around the physics, ecology, and engineering of flows around large wood. Results were disseminated via peer-reviewed publications, presentations at scientific and engineering conferences, via the project website (http://rivers.bee.oregonstate.edu/salmonid-behavior-and-hydraulics-engineered-log-jams), through the press, and in an outreach video (https://vimeo.com/109533630) to be shown at a local film festival. This project also provided mentored research experiences for 20 students, leading to 2 masters theses on modeling hydraulics of wood in rivers, one undergraduate honors thesis on the relationships between the flow field and foraging areas, research experiences for 2 high school students, 2 undergraduate research assistants, 11 REU students, 5 GRAs, 2 consultants, and 2 technicians. Of these 20 participants, 11 are women working in or pursuing educations in engineering and 7 are from underserved groups (ethnic minorities, first generation college students, etc.).

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Oregon State University
United States
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