Willamette Biological Opinion Chinook Reservoir Research 2013

Identification Information

Citation

Originator: ODFW

Publish Date: June 2014

Online Link: None

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Jeremy Romer

Job Position: Assistant Project Leader

Telephone: 541-757-4113

E-Mail Address: jeremy.d.romer@odfw.oregon.gov

Description

Abstract: In this report we investigate aspects of juvenile spring Chinook salmon Oncorhynchus tshawytscha life-history and rearing in select Willamette Valley Project (WVP) reservoirs to aid in the development of downstream passage options. In the first section, we assess the distribution of juvenile Chinook salmon in reservoirs. We provide information on the longitudinal distribution (head-of-reservoir to dam) of subyearlings in Detroit, Foster, Cougar, and Lookout Point reservoirs during spring. We also initiated a pilot study investigating longitudinal distribution of fall parr in Lookout Point Reservoir. We investigated changes in vertical distribution from July through November in Detroit and Lookout Point reservoirs. The second section compares growth rates between stream-rearing and reservoir-rearing subyearling Chinook salmon. We compare subyearling growth rates in all reservoirs listed above and Fall Creek Reservoir. In the third section, our objective was to assess and compare the infection prevalence and intensity of the parasitic copepod Salmincola califoriensis in salmonid species rearing in reservoirs and streams. In the fourth section, we assess fish species composition and predation rates on juvenile Chinook salmon and steelhead O. mykiss by predator species in Foster Reservoir. Finally, we assessed predator species abundance in Lookout Point Reservoir.

Purpose: The National Marine Fisheries Service concluded in the 2008 Willamette Project Biological Opinion (BiOp) that the continued operation and maintenance of the U.S. Army Corps of Engineers (USACE) Willamette Valley Project (WVP) would jeopardize the existence of Upper Willamette River spring Chinook salmon Oncorhynchus tshawytscha and Upper Willamette River steelhead O. mykiss (NMFS 2008). The BiOp concluded that lack of fish passage through WVP reservoirs and dams has one of the most significant adverse effects on both species and their habitat. The BiOp detailed specific actions, termed Reasonable and Prudent Alternative (RPA) measures that would “…allow for survival of the species with an adequate potential for recovery, and avoid destruction or modification of critical habitat”. Several RPA measures to the action agencies’ proposed actions were identified in the BiOp to address downstream fish passage concerns, notably, downstream fish passage structures (RPA 2.8; 4.8; 4.8.1; 4.9; 4.10; 4.12), head-of-reservoir juvenile collection facilities (RPA 4.9), and modifications to operational flows to improve conveyance of juvenile fish through the reservoirs. Assessing the feasibility of any of these proposed measures requires a baseline understanding of how juvenile salmonids use reservoir habitat. Understanding the life-history of juvenile spring Chinook salmon in WVP reservoirs will inform future management actions needed for population recovery. Currently, information is limited regarding juvenile Chinook salmon use of reservoirs, including seasonal distribution, migration rate, predator/prey interactions, growth rates, and the effect of reservoir rearing on parasites loads experienced by juveniles. In 2010, we began investigations in Cougar and Lookout Point reservoirs to further our understanding of these issues. In 2011 and 2012, we expanded our scope of sampling to include Detroit Reservoir and refined our techniques to address the critical uncertainties. In 2013, we included Foster Reservoir and investigated several aspects of juvenile Chinook salmon and steelhead life-history.

Time Period of Content:

Geographic Extent: Detroit, Foster, Cougar and Lookout Point Reservoirs in the Upper Willamette River Basin

Status: Final

Use Constraints:

Format: PDF

Data Quality Information

Lineage-Source: Cooperative Agreement: W9127N-10-2-0008 Task Order Number: 0020 Work Completed for Compliance with the 2008 Willamette Project Biological Opinion, USACE funding: 2013

Data Information

No data information was supplied.

Entity and Attribute Information

Attributes Description: Field attribute information is available in the database table field descriptions.

Is a physical copy maintained for reference at Headquarters? Unknown