A member of the Quantitative Fisheries Ecology Section, Columbia River Research Laboratory, Cook, WA. My career started in 1994 snorkeling for fishes in Idaho headwater streams. Shortly after, I became involved in telemetry projects assessing the effects of Snake and Columbia river dams on juvenile salmon.
In graduate school, I focused on the effects of lake conditions on native lake trout reproduction potential in Canada, and my doctoral research focused on the movement and growth of Snake River fall Chinook salmon over a period of population recovery. Today, I am involved a variety of fisheries topics including fish passage and survival at dams, environmental effects on fish fitness, and factors affecting natural and hatchery fish production over their life cycle. My goal is to provide useful information to resource managers for the wise use of our fisheries.
Research interests:
My work focuses on the quantitative aspect of fisheries. I specialize in the estimation of fish survival, movement, and growth from data obtained from passive and active telemetry and tagging technologies. I tailor statistical and mechanistic models to answer specific research and management questions related to environmental and human-induced effects on fish populations. For example, several of my current projects are (1) quantifying the life cycle production of naturally-produced Snake River fall Chinook salmon, (2) development and application of the S3 fish production model to assess the effects of flow management scenarios on juvenile Chinook and coho salmon in the Klamath and Trinity rivers, CA, and (3) assess the feasibility of reintroducing winter-run Chinook salmon above Shasta Dam, CA.
Professional Experience
2012 to Present - Fishery Biologist, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
2009-2012 - Doctoral student, University of Idaho, Moscow, Idaho, USA
2007-2009 - Fishery Biologist, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
2005-2007 - Graduate student, University of Manitoba, Winnipeg, Canada
02/97 - 2005 - Fishery Biologist, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
Education and Certifications
Ph.D. 2012. Natural Resources, University of Idaho, Moscow, ID
M.Sc. 2007. Zoology, University of Manitoba, Winnipeg, Canada
B.Sc. 1994. Biology, Ohio University, Athens, OH
Science and Products
Assessment of habitat use by juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Willamette River Basin, 2020–21
We conducted a field study during 2020–21 to describe habitat use patterns of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the mainstem Willamette, McKenzie, and Santiam Rivers and to evaluate how habitat suitability criteria affected the predictive accuracy of a hydraulic habitat model. Two approaches were used to collect habitat use data: a stratified sampling design was used to ensure
Simulating post-dam removal effects of hatchery operations and disease on juvenile Chinook salmon (Oncorhynchus tshawytscha) production in the Lower Klamath River, California
Executive SummaryThe Federal Energy Regulatory Commission has been considering the approval to breach four dams on lower Klamath River in southern Oregon and northern California. Approval of this application would allow for Strikeouts indicate text deletion hereafter. decommissioning and dam removal, beginning as early as 2023. This action would affect Klamath River salmon (Oncorhynchus ssp.) popu
Predator and prey events at the entrance of a surface‐oriented fish collector at North Fork Dam, Oregon
Development of a two-stage life cycle model for Oncorhynchus kisutch (coho salmon) in the upper Cowlitz River Basin, Washington
A temporally stratified extension of space‐for‐time Cormack–Jolly–Seber for migratory animals
Using the stream salmonid simulator (S3) to assess juvenile Chinook salmon (Oncorhynchus tshawytscha) production under historical and proposed action flows in the Klamath River, California
Application of the Stream Salmonid Simulator (S3) to Klamath River fall Chinook salmon (Oncorhynchus tshawytscha), California—Parameterization and calibration
Movement and apparent survival of acoustically tagged juvenile late-fall run chinook salmon released upstream of Shasta Reservoir, California
Juvenile Chinook salmon (Oncorhynchus tshawytscha) survival in Lookout Point Reservoir, Oregon, 2018
Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook Salmon ESU
Evaluation of Chinook salmon (Oncorhynchus tshawytscha) fry survival at Lookout Point Reservoir, western Oregon, 2017
Fish behavior and abundance monitoring near a floating surface collector in North Fork Reservoir, Clackamas River, Oregon, using multi-beam acoustic imaging sonar
Science and Products
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Filter Total Items: 52
Assessment of habitat use by juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Willamette River Basin, 2020–21
We conducted a field study during 2020–21 to describe habitat use patterns of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the mainstem Willamette, McKenzie, and Santiam Rivers and to evaluate how habitat suitability criteria affected the predictive accuracy of a hydraulic habitat model. Two approaches were used to collect habitat use data: a stratified sampling design was used to ensure
Simulating post-dam removal effects of hatchery operations and disease on juvenile Chinook salmon (Oncorhynchus tshawytscha) production in the Lower Klamath River, California
Executive SummaryThe Federal Energy Regulatory Commission has been considering the approval to breach four dams on lower Klamath River in southern Oregon and northern California. Approval of this application would allow for Strikeouts indicate text deletion hereafter. decommissioning and dam removal, beginning as early as 2023. This action would affect Klamath River salmon (Oncorhynchus ssp.) popu
Predator and prey events at the entrance of a surface‐oriented fish collector at North Fork Dam, Oregon
Quantifiable estimates of predator–prey interactions and relationships in aquatic habitats are difficult to obtain and rare, especially when individuals cannot be readily observed. To overcome this observational impediment, imaging sonar was used to assess the cooccurrence of predator‐size fish and juvenile salmonids, Oncorhynchus spp., at the entrance to a floating surface collector (FSC) in theDevelopment of a two-stage life cycle model for Oncorhynchus kisutch (coho salmon) in the upper Cowlitz River Basin, Washington
Recovery of salmon populations in the upper Cowlitz River Basin depends on trap-and-haul efforts owing to impassable dams. Therefore, successful recovery depends on the collection of out-migrating juvenile salmon at Cowlitz Falls Dam (CFD) for transport below downstream dams, as well as the collection of adults for transport upstream from the dams. Tacoma Power began downstream fish collection effA temporally stratified extension of space‐for‐time Cormack–Jolly–Seber for migratory animals
Understanding drivers of temporal variation in demographic parameters is a central goal of mark‐recapture analysis. To estimate the survival of migrating animal populations in migration corridors, space‐for‐time mark–recapture models employ discrete sampling locations in space to monitor marked populations as they move past monitoring sites, rather than the standard practice of using fixed samplinUsing the stream salmonid simulator (S3) to assess juvenile Chinook salmon (Oncorhynchus tshawytscha) production under historical and proposed action flows in the Klamath River, California
Executive SummaryThe production of Klamath River fall Chinook salmon (Oncorhynchus tshawytscha) in northern California and southern Oregon is thought to be limited by poor survival during freshwater juvenile life stages, in part a result of Ceratonova shasta—a highly infectious disease that can lead to high fish mortality. Higher flushing river flows are thought to affect the concentration of C. sApplication of the Stream Salmonid Simulator (S3) to Klamath River fall Chinook salmon (Oncorhynchus tshawytscha), California—Parameterization and calibration
Executive SummaryIn this report, we describe application of the Stream Salmonid Simulator (S3) to Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River between Keno Dam in southern Oregon and the ocean in northern California. S3 is a deterministic life-stage-structured population model that tracks daily growth, movement, and survival of juvenile salmon. It can track different source populMovement and apparent survival of acoustically tagged juvenile late-fall run chinook salmon released upstream of Shasta Reservoir, California
Stakeholder interests have spurred the reintroduction of the critically endangered populations of Chinook Salmon to tributaries upstream of Shasta Dam, in northern California. We released two groups of acoustically tagged, juvenile hatchery, late-fall Chinook Salmon to determine how juvenile salmon would distribute and survive. We measured travel times to Shasta Dam, and the number of fish that moJuvenile Chinook salmon (Oncorhynchus tshawytscha) survival in Lookout Point Reservoir, Oregon, 2018
A field study was conducted to estimate survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) in Lookout Point Reservoir, Oregon, during 2018. The study consisted of releasing three groups of genetically-marked fish into the reservoir, and sampling them monthly. Juveniles were released during April 10–13 (116,708 fish), May 15–18 (31,911 fish), and June 19–20 (11,758 fish). Reservoir sampResearch, 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) phenEvaluation of Chinook salmon (Oncorhynchus tshawytscha) fry survival at Lookout Point Reservoir, western Oregon, 2017
A field study was conducted to estimate survival of fry-sized juvenile Chinook salmon (Oncorhynchus tshawytscha) in Lookout Point Reservoir, western Oregon, during 2017. The field study consisted of releasing three groups of genetically marked fish in the reservoir and monthly fish sampling. Fish were released during April 18–19 (43,950 fish), May 30–June 2 (44,145 fish), and on June 28, 2017 (3,9Fish behavior and abundance monitoring near a floating surface collector in North Fork Reservoir, Clackamas River, Oregon, using multi-beam acoustic imaging sonar
An imaging sonar was used to assess the behavior and abundance of fish sized the same as salmonid smolt and bull trout (Salvelinus confluentus) at the entrance to the juvenile fish floating surface collector (FSC) at North Fork Reservoir, Oregon. The purpose of the FSC is to collect downriver migrating juvenile salmonids (Chinook salmon [Oncorhynchus tshawytscha], Coho salmon [Oncorhynchus kisutch