Selected under PLCI FY21 Umbrella Proj funding:

Larval Pacific lamprey have recently been detected in the mainstem Snake River.  This project will support collaborative assessment of larval Pacific lamprey distribution and habitat use in the mainstem Snake River below Hells Canyon Dam (HCD), with emphasis on understanding (and managing) effects of seasonal and daily flow fluctuations. The mainstem Snake River flow environment changes significantly both seasonally and daily as influenced by magnitude of water years, Columbia Basin flood control mandates, flow augmentation and diurnal load-following operations from HCD which dewater habitat associated with channel margins.  Flow changes may preclude larval rearing or result in stranding. We will sample the mainstem Snake River below HCD downstream to Asotin, WA (~164 km). Larval distribution will be evaluated in shallow-water, deep-water, and small tributary habitats using electrofishing and eDNA techniques.  Genetic analysis will be performed on larvae to determine whether they are offspring of translocated or volitional-returning adults.  A Lamprey Collaboratory (20 people, representing at least six entities) will be hosted with goals of data collection, habitat and sampling technique familiarity, and lamprey information sharing.  The first year will occur during stable flow conditions (October), with funding for a second year of sampling concurrent with daily flow fluctuations (September).  This project will support Snake Basin Larval Pacific Lamprey Collaboratories in 2021 and 2022 .  Collaboratories cover four days; including access/transportation to remote lodging and sampling locations, field data collection, and group presentations.

Pacific lamprey historically occupied the uppermost reaches of the Snake River and its tributaries above what is now the Hells Canyon Dam (HCD), which completely blocks anadromous fish access, and reduced available habitat by over 55% (Saul et al. 2001; IDFG, 2011). Prior to European settlement, approximately 500,000 adult lamprey migrated through the Hells Canyon region to reach spawning habitats in the Snake River (IDFG, 2011). Lamprey were documented by Gilbert and Evermann (1894) at the Lower Salmon Falls and lamprey harvest occurred at Shoshone Falls. The Hells Canyon Complex (Brownlee, Oxbow and Hells Canyon projects) stretches a 154 km reach of the Snake River and is undergoing FERC relicensing, with anticipation of the issuance of a new long-term license by 2022. The complex currently operates on an annual license under the terms of an Interim Settlement Agreement relative to ESA species since the license expired in July 2005. This is an opportunity to determine larval lamprey occupancy and use of the littoral zone below HCD, and to understand how flow fluctuations may contribute to the distribution, displacement or stranding of larvae lamprey. This research may provide guidance towards flow management to benefit Pacific lamprey, and potentially juvenile fall Chinook.  BPA, under several Accords subcontracts, has funded translocation of adult lamprey into the Snake Basin.  This 2 year project will perform monitoring that will inform results from this translocation work.  In addition, lamprey populations in the Snake basin have been impacted by the multiple federal dams downstream (depressed populations/abundance/distribution) and thus funding this work is a shared mitigation responsibility - cost share with Idaho Power (subcontract) is a fundamental component of this project.