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200717000 - South Fork Snake River Yellowstone cutthroat trout recruitment and survival improvement

Sponsor: Idaho Department of Fish & Game

Budgets: FY07: $1,105,100 | FY08: $1,107,400 | FY09: $1,011,700

Short description: Increase juvenile Yellowstone cutthroat trout recruitment and survival in the South Fork of the Snake River by minimizing entrainment losses and side channel stranding mortality, and by restoring tributary habitat.

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Final Council recommendation (Nov 2006)

Funding category: Expense

Recommended budgets: FY07: $205,100 | FY08: $357,400 | FY09: $688,343

Comment: Project budget has been aligned to reflect sequencing from assessment/planning to implementation. Budget in out years increases as planning is completed and screens are installed. Need to determine if any of this should be capitalized

ISRP final recommendation: Fundable


This is a new proposal from IDF&G focusing on native Yellowstone cutthroat trout in the South Fork of the Snake River in eastern Idaho. The proposal is well written and logical, and refers to relevant recent studies and results within the South Fork system. The project proposes to upgrade existing picket weir traps in four important upper river spawning tributaries for Yellowstone cutthroat trout. The weirs allow managers to keep introduced rainbow trout out of the tributaries and to therefore avoid hybridization - at least in these major tributaries. Rainbow trout are now well established in the mainstem and are a significant threat to the genetic integrity and population viability of the South Fork cutthroat trout population. A second important objective of the proposed project is to install irrigation screens on four lower river feeder canals where entrainment of juvenile Yellowstone cutthroat trout is thought to be a limiting factor in their abundance in the lower river section. The proposal does not justify, with data, that entrainment in the diversions is actually a problem. But this is likely a good assumption considering the volume of water being moved. The proposed project fits extremely well with local and regional planning documents. This is a new project, but linkages are made to other existing projects within the drainage. A strong collaborative effort is ongoing to preserve native cutthroat on South Fork There are two clearly stated Objectives - to screen one lower river diversion per year, and to replace pickets in one existing weir per year. Screening the diversions should reduce entrainment losses, but reviewers are asked to take that on faith. Tasks (work elements) and methods are clearly stated -- straightforward engineering. Facilities, equipment, and personnel are excellent Monitoring of trout populations to verify expected results is referred to within the proposal but is not explicitly detailed. This is not particularly surprising, as the project is primarily a capital expense and facilities upgrade project, rather than a research project. Nevertheless, several assumptions are made that monitoring could be used (and should be used) to verify. One such assumption is that keeping the Yellowstone populations in the upper river tributaries (Pine, Rainey, etc,) free from rainbow trout introgression (via the picket weirs and genetic sampling) will be adequate to keep rainbow numbers down and Yellowstone cutthroat trout abundance high. This may be correct - and monitoring would show that - but it may also be overly optimistic. Information transfer is adequate. One also hopes that peer reviewed publications will emerge from this larger study.

State/province recommendation: Fundable

Review group: Snake

Recommended budgets: FY07: $205,100 | FY08: $357,400 | FY09: $688,343

Comment: Fish screens are not ready for installation. Budget in out years increases as planning is completed and screens are installed.