Monitoring upstream migration and potential causes of prespawn mortality in adult UWR Chinook, 2015
Project ID: W912HZ-15-2-0009
Federal Agency: U.S. Army Corps of Engineers
Partner Institution: University of Idaho
Fiscal Year: 2015
Initial Funding: $475,931
Total Funding: $475,931
Principal Investigator: Caudill, Christopher
Agreement Technical Representative: Whitaker, Sherry
Abstract: The overarching goal of this study is to gain information on the relationships between upstream migration history, river environment, fish condition and disease expression, collection and outplant methods, and spawning success/pre-spawning mortality for adult Upper Willamette
River (UWR) Chinook salmon (Oncorhynchus tshawytscha). Information will be used to understand the relationships between adult upstream migration behavior, tributary holding and USACE Willamette Valley Project (WVP) operations and to improve natural production from salmon collected and transported upstream (outplanted) of WVP dams and reservoirs. Establishing the mechanism(s) or cause(s) of prespawning mortality (PSM) of fish in the upper Willamette River basin and those outplanted above barrier dams may be critical to the success of recovery measures because, on an individual basis, mature adults contribute the most to population growth rate compared to other life history stages. In 2015, we will address three general research questions:
1) What is the behavior and migration success of adult Chinook salmon in the main stem Willamette River and tributaries and how does it relate to WVP conditions and operations?
2) To what degree is PSM after trapping and outplanting associated with factors related to ocean experience, mainstem migration conditions, trapping and handling, or conditions encountered in spawning tributaries after outplanting? and
3) How do holding and outplant practices affect spawning?
The broader goals are to 1) develop operations that provide suitable migration conditions in the main stem Willamette River, 2) recommend management options that could reduce prespawning mortality and 3) provide information that could allow for prediction of prespawning mortality in the future based on environmental conditions and management actions.
Study sites in 2015 will include the North Santiam River (Minto, Big Cliff, and Detroit dams), Middle Fork Willamette River (Dexter, Lookout Point, Hills Creek, and Fall Creek dams), and the South Santiam River (Foster Dam).