Pacific Lamprey Passage Evaluations at Hatchery Facilities in Southwest Washington State

Broad goals were to: 1) assess hatchery fishways, barrier dams, and related passage structures that may significantly delay or preclude passage of adult Pacific Lamprey in the Lower Columbia River Basin, 2) provide practical recommendations on how to accommodate beneficial retrofits of existing structures for persons designing, operating, managing and maintaining these structures, 3) recommend additional studies to further refine and identify passage concerns.

Throughout the Lower Columbia River Basin in SW Washington, there are approximately 15 fish hatcheries on Columbia River tributaries downstream of Bonneville Dam. Many hatcheries use barrier dams and fishways to convey adult salmon into the hatchery proper and to pond up water for gravity-fed water delivery systems. These structures could be significant barriers to adult Pacific Lamprey returning to spawn upstream. The degree to which these hatcheries limit or delay lamprey passage has not been evaluated. Previous evaluations at other hatcheries usually identified significant passage issues for Pacific Lamprey.

USFWS staff: (1) conducted systematic fishway inspections of fishways and barrier dams at hatcheries using Pacific Lamprey-specific passage guidelines. The hatcheries assessed included Beaver Creek Hatchery, Abernathy Fish Technology Center, Fallert Creek Hatchery, Kalama Falls Hatchery, Skamania Hatchery, Washougal Hatchery, Sea Resources Hatchery, North Toutle Hatchery, Grays River Hatchery Cowlitz Trout and Cowlitz Salmon hatcheries and the Lewis River Hatchery, (2) as required, will conduct on-site presentations of findings with relevant management staff and partners, (3) produce a summary graphic report that includes issues identified, passage solutions, and recommendations for future evaluations.

This study did not explicitly evaluate entrainment of larval lamprey into hatchery facilities.

The passage guidelines used in the evaluation to evaluate Pacific Lamprey passage are based on: Lamprey Technical Workgroup. 2022. Practical guidelines for incorporating adult Pacific lamprey passage at fishways, Version 2.0. White Paper. 50 pp + Appendixes. Available online: https://www.pacificlamprey.org/ltwg/