Snake River fall Chinook salmon were listed as “threatened” under the ESA in 1992. My entire career has focused conducting applied research to provide information that would increase our understanding of this unique stock and facilitate recovery efforts.
The work of myself and colleagues from other agencies have produced most of the contemporary information on Snake River fall Chinook salmon.
Research Interests:
The main focus of my work is understanding Snake River fall Chinook salmon life history and ecology to support recovery of this listed stock. Over the years research topics have included migratory behavior, habitat use and quantification, physiology, and feeding ecology of juvenile fish in the Snake and Columbia rivers. Other research areas have included understanding the effects of elevated flows on chum salmon spawning behavior, and investigating recent food web changes to lower Snake River reservoirs.
Professional Experience
1992 to Present – Research Fish Biologist, U.S. Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA
Education and Certifications
M.S. 1992. Fishery Biology, Colorado State University, Fort Collins, CO
B.S. 1987. Fishery Biology, Colorado State University, Fort Collins, CO
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Snake River Fall Chinook Salmon Research - Cooperator Publications
Snake River Fall Chinook Salmon Research
Backpack electrofishing does not contribute to external signs of gas bubble trauma in sculpins
Monitoring native, resident nonsalmonids for the incidence of gas bubble trauma downstream of Snake and Columbia River Dams, 2021
Performance of subyearling fall Chinook salmon tagged with 8‐, 9‐, and 12‐mm passive integrated transponder tags in the Snake River
Impact of smallmouth bass predation on subyearling fall Chinook salmon over a broad river continuum
Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River Fall Chinook Salmon ESU: January 2019 - December 2019
A field evaluation of the growth and survival of age-0 Oncorhynchus mykiss tagged with 8-mm passive integrated transponder (PIT) tags
Snake River fall chinook salmon life history investigations, 2018 annual report
Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook Salmon ESU
Fall Chinook salmon (Oncorhynchus tshawytscha), sand roller (Percopsis transmontana), and smallmouth bass (Micropterus dolomieu) interactions in a Snake River reservoir: A tale of three species
Post‐release predation mortality of age‐0 hatchery‐reared Chinook salmon from non‐native smallmouth bass in the Snake River
Upstream migration and spawning success of Chinook salmon in a highly developed, seasonally warm river system
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Snake River Fall Chinook Salmon Research - Cooperator Publications
Snake River Fall Chinook Salmon Research - Cooperator PublicationsSnake River Fall Chinook Salmon Research
Snake River fall Chinook salmon were listed as “threatened” under the Endangered Species Act in 1992. At that time, little was known about the spawning, rearing, migration, and life history of this species. This long-term research and monitoring project has produced much of the contemporary knowledge on fall Chinook salmon that has been used by fish managers to implement recovery measures. The... - Publications
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Backpack electrofishing does not contribute to external signs of gas bubble trauma in sculpins
We exposed prickly sculpin Cottus asper and reticulate sculpin Cottus perplexus to electroshock and sham treatments in a controlled laboratory setting to determine if backpack electrofishing contributed to or exacerbated external signs of gas bubble trauma (GBT) in fish exposed to elevated total dissolved gas (TDG) levels. Fish were exposed to 115, 120 and 125% TDG (measured as percent of saturatiMonitoring native, resident nonsalmonids for the incidence of gas bubble trauma downstream of Snake and Columbia River Dams, 2021
In 2020, a new spill program was implemented to aid the downstream passage of juvenile salmonids at mainstem dams on the Snake and Columbia rivers. Under this program, the total dissolved gas (TDG) cap was increased to 125% and monitoring of native, resident nonsalmonid (NRN) fishes for gas bubble trauma (GBT) became a requirement. The primary objective of this work was to measure the incidencPerformance of subyearling fall Chinook salmon tagged with 8‐, 9‐, and 12‐mm passive integrated transponder tags in the Snake River
Inferences based on tagged individuals from a population are limited in part by the minimum size of fish that can be tagged. Smaller tags allow a greater proportion of a population to be represented by tagging and should reduce potential tag effects on fish performance. We evaluated different performance metrics of juvenile fall Chinook Salmon Oncorhynchus tshawytscha tagged with 8‐, 9‐, and 12‐mmImpact of smallmouth bass predation on subyearling fall Chinook salmon over a broad river continuum
Smallmouth bass (Micropterus dolomieu) predation on subyearling fall Chinook salmon (Oncorhynchus tshawytscha) was examined in the Snake River (USA) to identify seasonal and habitat-related changes in bass diets, and associated subyearling consumption and loss in various riverine and impounded reaches. Smallmouth bass diets reflected opportunistic foraging that at times showed predation on subyearResearch, monitoring, and evaluation of emerging issues and measures to recover the Snake River Fall Chinook Salmon ESU: January 2019 - December 2019
The portion of the Snake River fall Chinook salmon Oncorhynchus tshawytscha evolutionary significant unit (ESU) that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 19922019 in association with U.S. Endangered Species Act recovery efforts and other federally mandated actions. This annual report focuses on (1) numeric and habitat use responses by natural- and hatA field evaluation of the growth and survival of age-0 Oncorhynchus mykiss tagged with 8-mm passive integrated transponder (PIT) tags
BackgroundIn fish tagging studies, tag size limits the size of fish that can be tagged, the fraction of a population that can be represented, and ultimately inferences that can be made about the study population, particularly when juvenile fish are the subject of interest. Introduction of an 8-mm passive integrated transponder (PIT) reduced the minimum taggable size of fish, but it has not been evSnake River fall chinook salmon life history investigations, 2018 annual report
The following report is divided into three sections each of which describes work conducted by different project cooperators. Chapter One describes smallmouth bass (Micropterus dolomieu) predation on subyearling fall Chinook salmon (Oncorhynchus tshawytscha) in Lower Granite Reservoir in 2018. Smallmouth bass abundance increased seasonally in shoreline habitats and was highest in the lower reach ofResearch, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook Salmon ESU
The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2018 in association with U.S. Endangered Species Act recovery efforts and other federally mandated actions. This annual report focuses on (1) numeric and habitat use responses by natural- and hatchery-origin spawners, (2) phenFall Chinook salmon (Oncorhynchus tshawytscha), sand roller (Percopsis transmontana), and smallmouth bass (Micropterus dolomieu) interactions in a Snake River reservoir: A tale of three species
We studied some of the relationships between federally listed fall Chinook Salmon, Oncorhynchus tshawytscha, endemic Sand Roller, Percopsis transmontana, and non-native Smallmouth Bass, Micropterus dolomieu, in Lower Granite Reservoir on the Snake River. Because of its recent reappearance and population increase, the Sand Rollers could be filling the role of a “native invader” in the reservoir fooPost‐release predation mortality of age‐0 hatchery‐reared Chinook salmon from non‐native smallmouth bass in the Snake River
Release of age‐0 hatchery‐reared fall Chinook salmon, Oncorhynchus tshawytscha(Walbaum), in the Snake River resulted in up to 30‐fold increases in salmon consumption by non‐native smallmouth bass, Micropterus dolomieu Lacepѐde. In an upper river reach, smallmouth bass fed intensively during a release in May, but Chinook salmon consumption returned to pre‐release levels within 1–2 days as hatchery‐Upstream migration and spawning success of Chinook salmon in a highly developed, seasonally warm river system
This review summarizes what is known about the influence of water temperature and velocity on the migration and spawning success of an inland population of Chinook salmon Oncorhynchus tshawytscha. Models are then developed and used to illustrate how migration and spawning success might change if temperatures and velocities increase under a future climate. The illustration shows the potential for m - News
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