Gabriel is a Biologist at the USGS, Columbia River Research Laboratory.
Professional Experience
2001 to Present – Biological Science Technician, U.S. Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA
Education and Certifications
B.S. Environmental Science, Washington State University, Pullman, WA
Science and Products
Filter Total Items: 17
Behavior and movement of smallmouth bass (Micropterus dolomieu) near Bonneville Dam, Columbia River, Washington and Oregon, March–October 2022
A telemetry study was conducted during March–October 2022 to evaluate behavior and movement patterns of adult smallmouth bass (Micropterus dolomieu) in the forebay of Bonneville Dam, on the Columbia River in Washington and Oregon. This study was a follow-up to a previous study conducted at the site during August–December 2020. In 2022, a total of 41 smallmouth bass were collected, tagged, and rele
Authors
Tobias J. Kock, Gabriel S. Hansen
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
Authors
Gabriel S. Hansen, Russell W. Perry, Tobias J. Kock, James S. White, Philip V. Haner, John M. Plumb, J. Rose Wallick
Synthesis of habitat availability and carrying capacity research to support water management decisions and enhance conditions for Pacific salmon in the Willamette River, Oregon
Flow management is complex in the Willamette River Basin where the U.S. Army Corps of Engineers owns and operates a system of 13 dams and reservoirs (hereinafter Willamette Project), which are spread throughout three large tributaries including the Middle Fork Willamette, McKenzie, and Santiam Rivers. The primary purpose of the Willamette Project is flood-risk management, which provides critical p
Authors
Tobias J. Kock, Russell W. Perry, Gabriel S. Hansen, James White, Laurel E. Stratton Garvin, J. Rose Wallick
Behavior and movement of smallmouth bass (Micropterus dolomieu) in the forebay of Bonneville Dam, Columbia River, August–December 2020
A telemetry study was conducted during August–December 2020 to evaluate behavior and movement patterns of adult smallmouth bass (Micropterus dolomieu) in the forebay of Bonneville Dam, Washington. A total of 40 smallmouth bass were collected, tagged, and released during August–September in seven distinct areas of the dam forebay and monitored until mid-December. Movement data from 36 tagged smallm
Authors
Tobias J. Kock, Gabriel S. Hansen, Scott D. Evans
From drought to deluge: Spatiotemporal variation in migration routing, survival, travel time and floodplain use of an endangered migratory fish
We developed a novel statistical model to relate the daily survival and migration dynamics of an endangered anadromous fish to river flow and water temperature during both extreme drought and severe flooding in an intensively managed river system. Our Bayesian temporally stratified multistate mark recapture model integrates over unobserved travel times and route transitions to efficiently estimate
Authors
Dalton Hance, Russell Perry, Adam Pope, Arnold J. Ammann, Jason L. Hassrick, Gabriel S. Hansen
Juvenile 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 samp
Authors
Tobias J. Kock, Russell W. Perry, Gabriel S. Hansen, Philip V. Haner, Adam C. Pope, John M. Plumb, Karen M. Cogliati, Amy C. Hansen
Evaluation 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 (3,9
Authors
Tobias J. Kock, Russell W. Perry, Gabriel S. Hansen, Philip V. Haner, Adam C. Pope, John M. Plumb, Karen M. Cogliati, Amy C. Hansen
Synthesis of downstream fish passage information at projects owned by the U.S. Army Corps of Engineers in the Willamette River Basin, Oregon
The U.S. Army Corps of Engineers (USACE) operates the Willamette Valley Project (Project) in northwestern Oregon, which includes a series of dams, reservoirs, revetments, and fish hatcheries. Project dams were constructed during the 1950s and 1960s on rivers that supported populations of spring Chinook salmon (Oncorhynchus tshawytscha), winter steelhead (O. mykiss), and other anadromous fish speci
Authors
Amy C. Hansen, Tobias J. Kock, Gabriel S. Hansen
Evaluation of the biological and hydraulic performance of the portable floating fish collector at Cougar Reservoir and Dam, Oregon, September 2015–January 2016
The biological and hydraulic performance of a portable floating fish collector (PFFC) located in the cul-de-sac of Cougar Dam and Reservoir, Oregon, was evaluated during 2015–16. The PFFC, first commissioned in May 2014, was modified during winter 2014–15 to address several deficiencies identified during operation and testing in 2014. These modifications included raising the water inflow structure
Authors
John W. Beeman, Scott D. Evans, Philip V. Haner, Hal C. Hansel, Amy C. Hansen, Gabriel S. Hansen, Tyson W. Hatton, Eric E. Kofoot, Jamie M. Sprando
Evaluation of the hydraulic and biological performance of the portable floating fish collector at Cougar Reservoir and Dam, Oregon, 2014
The biological and hydraulic performance of a new portable floating fish collector (PFFC) located in a cul-de-sac within the forebay of Cougar Dam, Oregon, was evaluated during 2014. The purpose of the PFFC was to explore surface collection as a means to capture juvenile salmonids at one or more sites using a small, cost-effective, pilot-scale device. The PFFC used internal pumps to draw attractio
Authors
John W. Beeman, Scott D. Evans, Philip V. Haner, Hal C. Hansel, Amy C. Hansen, Gabriel S. Hansen, Tyson W. Hatton, Jamie M. Sprando, Collin D. Smith, Noah S. Adams
Behavior, passage, and downstream migration of juvenile Chinook salmon from Detroit Reservoir to Portland, Oregon, 2014–15
An evaluation was conducted to estimate dam passage survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) at Detroit Dam during a period of spill. To estimate dam passage survival, we used a paired-release recapture study design and released groups of tagged fish upstream (997 fish) and downstream (625 fish) of Detroit Dam. A total of 43 fish (6.8 percent) passed Detroit Dam from the upst
Authors
Tobias J. Kock, John W. Beeman, Amy C. Hansen, Hal C. Hansel, Gabriel S. Hansen, Tyson W. Hatton, Eric E. Kofoot, Matthew D. Sholtis, Jamie M. Sprando
An evaluation of fish behavior upstream of the water temperature control tower at Cougar Dam, Oregon, using acoustic cameras, 2013
This report describes the initial year of a 2-year study to determine the feasibility of using acoustic cameras to monitor fish movements to help inform decisions about fish passage at Cougar Dam near Springfield, Oregon. Specifically, we used acoustic cameras to measure fish presence, travel speed, and direction adjacent to the water temperature control tower in the forebay of Cougar Dam during t
Authors
Noah S. Adams, Collin Smith, John M. Plumb, Gabriel S. Hansen, John W. Beeman
Science and Products
- Publications
Filter Total Items: 17
Behavior and movement of smallmouth bass (Micropterus dolomieu) near Bonneville Dam, Columbia River, Washington and Oregon, March–October 2022
A telemetry study was conducted during March–October 2022 to evaluate behavior and movement patterns of adult smallmouth bass (Micropterus dolomieu) in the forebay of Bonneville Dam, on the Columbia River in Washington and Oregon. This study was a follow-up to a previous study conducted at the site during August–December 2020. In 2022, a total of 41 smallmouth bass were collected, tagged, and releAuthorsTobias J. Kock, Gabriel S. HansenAssessment 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
AuthorsGabriel S. Hansen, Russell W. Perry, Tobias J. Kock, James S. White, Philip V. Haner, John M. Plumb, J. Rose WallickSynthesis of habitat availability and carrying capacity research to support water management decisions and enhance conditions for Pacific salmon in the Willamette River, Oregon
Flow management is complex in the Willamette River Basin where the U.S. Army Corps of Engineers owns and operates a system of 13 dams and reservoirs (hereinafter Willamette Project), which are spread throughout three large tributaries including the Middle Fork Willamette, McKenzie, and Santiam Rivers. The primary purpose of the Willamette Project is flood-risk management, which provides critical pAuthorsTobias J. Kock, Russell W. Perry, Gabriel S. Hansen, James White, Laurel E. Stratton Garvin, J. Rose WallickBehavior and movement of smallmouth bass (Micropterus dolomieu) in the forebay of Bonneville Dam, Columbia River, August–December 2020
A telemetry study was conducted during August–December 2020 to evaluate behavior and movement patterns of adult smallmouth bass (Micropterus dolomieu) in the forebay of Bonneville Dam, Washington. A total of 40 smallmouth bass were collected, tagged, and released during August–September in seven distinct areas of the dam forebay and monitored until mid-December. Movement data from 36 tagged smallmAuthorsTobias J. Kock, Gabriel S. Hansen, Scott D. EvansFrom drought to deluge: Spatiotemporal variation in migration routing, survival, travel time and floodplain use of an endangered migratory fish
We developed a novel statistical model to relate the daily survival and migration dynamics of an endangered anadromous fish to river flow and water temperature during both extreme drought and severe flooding in an intensively managed river system. Our Bayesian temporally stratified multistate mark recapture model integrates over unobserved travel times and route transitions to efficiently estimateAuthorsDalton Hance, Russell Perry, Adam Pope, Arnold J. Ammann, Jason L. Hassrick, Gabriel S. HansenJuvenile 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 sampAuthorsTobias J. Kock, Russell W. Perry, Gabriel S. Hansen, Philip V. Haner, Adam C. Pope, John M. Plumb, Karen M. Cogliati, Amy C. HansenEvaluation 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 (3,9AuthorsTobias J. Kock, Russell W. Perry, Gabriel S. Hansen, Philip V. Haner, Adam C. Pope, John M. Plumb, Karen M. Cogliati, Amy C. HansenSynthesis of downstream fish passage information at projects owned by the U.S. Army Corps of Engineers in the Willamette River Basin, Oregon
The U.S. Army Corps of Engineers (USACE) operates the Willamette Valley Project (Project) in northwestern Oregon, which includes a series of dams, reservoirs, revetments, and fish hatcheries. Project dams were constructed during the 1950s and 1960s on rivers that supported populations of spring Chinook salmon (Oncorhynchus tshawytscha), winter steelhead (O. mykiss), and other anadromous fish speciAuthorsAmy C. Hansen, Tobias J. Kock, Gabriel S. HansenEvaluation of the biological and hydraulic performance of the portable floating fish collector at Cougar Reservoir and Dam, Oregon, September 2015–January 2016
The biological and hydraulic performance of a portable floating fish collector (PFFC) located in the cul-de-sac of Cougar Dam and Reservoir, Oregon, was evaluated during 2015–16. The PFFC, first commissioned in May 2014, was modified during winter 2014–15 to address several deficiencies identified during operation and testing in 2014. These modifications included raising the water inflow structureAuthorsJohn W. Beeman, Scott D. Evans, Philip V. Haner, Hal C. Hansel, Amy C. Hansen, Gabriel S. Hansen, Tyson W. Hatton, Eric E. Kofoot, Jamie M. SprandoEvaluation of the hydraulic and biological performance of the portable floating fish collector at Cougar Reservoir and Dam, Oregon, 2014
The biological and hydraulic performance of a new portable floating fish collector (PFFC) located in a cul-de-sac within the forebay of Cougar Dam, Oregon, was evaluated during 2014. The purpose of the PFFC was to explore surface collection as a means to capture juvenile salmonids at one or more sites using a small, cost-effective, pilot-scale device. The PFFC used internal pumps to draw attractioAuthorsJohn W. Beeman, Scott D. Evans, Philip V. Haner, Hal C. Hansel, Amy C. Hansen, Gabriel S. Hansen, Tyson W. Hatton, Jamie M. Sprando, Collin D. Smith, Noah S. AdamsBehavior, passage, and downstream migration of juvenile Chinook salmon from Detroit Reservoir to Portland, Oregon, 2014–15
An evaluation was conducted to estimate dam passage survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) at Detroit Dam during a period of spill. To estimate dam passage survival, we used a paired-release recapture study design and released groups of tagged fish upstream (997 fish) and downstream (625 fish) of Detroit Dam. A total of 43 fish (6.8 percent) passed Detroit Dam from the upstAuthorsTobias J. Kock, John W. Beeman, Amy C. Hansen, Hal C. Hansel, Gabriel S. Hansen, Tyson W. Hatton, Eric E. Kofoot, Matthew D. Sholtis, Jamie M. SprandoAn evaluation of fish behavior upstream of the water temperature control tower at Cougar Dam, Oregon, using acoustic cameras, 2013
This report describes the initial year of a 2-year study to determine the feasibility of using acoustic cameras to monitor fish movements to help inform decisions about fish passage at Cougar Dam near Springfield, Oregon. Specifically, we used acoustic cameras to measure fish presence, travel speed, and direction adjacent to the water temperature control tower in the forebay of Cougar Dam during tAuthorsNoah S. Adams, Collin Smith, John M. Plumb, Gabriel S. Hansen, John W. Beeman - News