Pacific Lamprey Migration Study
Willamette River Basin, OR
To address questions about lamprey migration patterns and distribution, Cascade analyzed radio-telemetry data for Pacific lamprey (Entosphenus tridentatus) movement in the upper Wilamette Basin over a five-year period, from 2008 to 2012.
Cascade organized the lamprey dataset, analyzed the data, and provided a comprehensive and technically-sound document to both report and communicate the study’s findings to a broad audience. The report addressed the following objectives: determining lamprey upstream migration timing and movement patterns, identifying overwintering locations, quantifying the relative use of primary tributaries for spawning, and determining the relationship between lamprey movement and key environmental correlates (e.g., water temperature and flow). A literature review of relevant lamprey studies with emphasis on Willamette Basin studies informed the data analysis and assured alignment with other Willamette Basin lamprey studies.
Through this report, Cascade contributed to the understanding of the upstream migration patterns of adult Pacific lamprey and their use of river habitats throughout the Willamette Basin. Additionally, we provided management and future research recommendations.