Tobias J Kock
I am a Supervisory Research Fish Biologist at the Columbia River Research Laboratory, Cook, WA. I began working on fisheries studies in 1998. My research has focused on Pacific salmon, dams and ecology in the Pacific Northwest. My expertise includes the use of telemetry systems to monitor juvenile and adult salmon and steelhead. I currently work on the Columbia, Willamette, and Yakima Rivers.
My research team conducts investigations into dam passage and survival for juvenile and adult Pacific salmon, assesses fish collection and passage devices, researches the ecological effects of high-head dams and reservoirs on anadromous fish, and evaluates various aspects of salmon and steelhead reintroductions upstream of impassable dams. I am currently working on studies that evaluate the effects of flow management on juvenile salmon survival, the responses of adult salmon and steelhead to trap-and-haul, assessment of dam-passage survival of juvenile salmon, and developing methods to estimate survival of salmon fry in reservoirs. My research is highly collaborative. I work closely with Tribal, State and Federal partners to provide unbiased science for use by a diverse group of stakeholders in several watersheds in the western United States.
Professional Experience
2016-Present – Supervisory Research Fish Biologist, U.S. Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA
2002 to 2016 - Fish Biologist, U.S. Geological Survey, Western Fisheries Science Center, Columbia River Research Laboratory, Cook, WA
2000-2002 - Graduate Student, University of Idaho, Moscow, ID
1998-2000 - Biological Science Technician, University of Idaho and U.S. Geological Survey
Education and Certifications
M.S. 2004. Fisheries Science, University of Idaho, Moscow, ID
B.A. 2000. Biology, Minor in Religion, Pacific Lutheran University, Tacoma, WA
Affiliations and Memberships*
American Fisheries Society
AFS-BES/ASCE-EWRI Joint Committee on Fisheries Engineering and Science (Webinar Task Group Member)
Science and Products
Benefits of prescribed flows for salmon smolt survival enhancement vary longitudinally in a highly managed river system
Dam operations affect route-specific passage and survival of juvenile Chinook salmon at a main-stem diversion dam
Angler harvest, hatchery return, and tributary stray rates of recycled adult summer steelhead Oncorhynchus mykiss in the Cowlitz River, Washington
Behavior, passage, and downstream migration of juvenile Chinook salmon from Detroit Reservoir to Portland, Oregon, 2014–15
Evaluation of two juvenile salmon collection devices at Cowlitz Falls Dam, Washington, 2014
Evaluation of stream flow effects on smolt survival in the Yakima River Basin, Washington, 2012-2014
Evaluation of the behavior and movement of adult summer steelhead in the lower Cowlitz River, Washington, following collection and release, 2013-2014
Post-release behavior and movement patterns of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) after capture using alternative commercial fish gear, lower Columbia River, Washington and Oregon, 2013
Evaluation of juvenile salmonid behavior near a prototype weir box at Cowlitz Falls Dam, Washington, 2013
Evaluation of the behavior and movement patterns of adult coho salmon and steelhead in the North Fork Toutle River, Washington, 2005-2009
Review of a model to assess stranding of juvenile salmon by ship wakes along the Lower Columbia River, Oregon and Washington
Snake River fall Chinook salmon life history investigations: Annual report 2011 (April 2011 - March 2012)
Science and Products
- Science
- Multimedia
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Filter Total Items: 66
Benefits of prescribed flows for salmon smolt survival enhancement vary longitudinally in a highly managed river system
The influence of streamflow on survival of emigrating juvenile Pacific salmonids Oncorhynchus spp. (smolts) is a major concern for water managers throughout the northeast Pacific Rim. However, few studies have quantified flow effects on smolt survival, and available information does not indicate a consistent flow–survival relationship within the typical range of flows under management control. InAuthorsIan Courter, Thomas Garrison, Tobias J. Kock, Russell W. Perry, David Child, Joel HubbleDam operations affect route-specific passage and survival of juvenile Chinook salmon at a main-stem diversion dam
Diversion dams can negatively affect emigrating juvenile salmon populations because fish must pass through the impounded river created by the dam, negotiate a passage route at the dam and then emigrate through a riverine reach that has been affected by reduced river discharge. To quantify the effects of a main-stem diversion dam on juvenile Chinook salmon in the Yakima River, Washington, USA, we uAuthorsRussell W. Perry, Tobias J. Kock, Ian I Couter, Thomas M Garrison, Joel D Hubble, David B ChildAngler harvest, hatchery return, and tributary stray rates of recycled adult summer steelhead Oncorhynchus mykiss in the Cowlitz River, Washington
Hatchery ‘recycling’ programs have been used to increase angling opportunities by re-releasing fish into a river after they returned to a hatchery or fish trap. Recycling is intended to increase opportunities for fishermen, but this strategy could affect wild fish populations if some recycled fish remain in the river and interact with wild fish populations. To quantify hatchery return and angler hAuthorsTobias J. Kock, Russell W. Perry, Chris Gleizes, Wolf Dammers, Theresa L. LiedtkeBehavior, 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. SprandoEvaluation of two juvenile salmon collection devices at Cowlitz Falls Dam, Washington, 2014
Collection of juvenile salmon at Cowlitz Falls Dam is a critical part of the effort to restore salmon in the upper Cowlitz River, Washington. Many of the fish that are not collected pass downstream and enter Riffe Lake, become landlocked, and are lost to the anadromous population. In addition to this loss, the juvenile fish collection system at Cowlitz Falls Dam, which originally consisted of fourAuthorsTobias J. Kock, Theresa L. Liedtke, Brian K. Ekstrom, William HurstEvaluation of stream flow effects on smolt survival in the Yakima River Basin, Washington, 2012-2014
The influence of stream flow on survival of emigrating juvenile (smolts) Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss is of key management interest. However, few studies have quantified flow effects on smolt migration survival, and available information does not indicate a consistent flow-survival relationship within the typical range of flows under management control. It is hypAuthorsIan Courter, Tommy Garrison, Tobias J. Kock, Russell W. PerryEvaluation of the behavior and movement of adult summer steelhead in the lower Cowlitz River, Washington, following collection and release, 2013-2014
Summer steelhead (Oncorhynchus mykiss) produced by a hatchery on the lower Cowlitz River, Washington, support a popular sport fishery during June–September each year. Many of these fish return to the Cowlitz Salmon Hatchery and are held until they are spawned in December. In the past, fishery managers have released some of the steelhead that return to the hatchery at downstream release sites (hereAuthorsTobias J. Kock, Theresa L. Liedtke, Brian K. Ekstrom, Chris Gleizes, Wolf DammersPost-release behavior and movement patterns of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) after capture using alternative commercial fish gear, lower Columbia River, Washington and Oregon, 2013
Commercial salmon Oncorhynchus spp. fishers traditionally have used gill nets, and more recently tangle nets, to capture adult salmon in the lower Columbia River, Washington and Oregon, but these gear types are not selective and can result in unintentional injury or death to non-target species, which is a problem when wild or Endangered Species Act-listed salmon are present. Gill and tangle nets cAuthorsTheresa L. Liedtke, Tobias J. Kock, Scott D. Evans, Gabriel S. Hansen, Dennis W. RondorfEvaluation of juvenile salmonid behavior near a prototype weir box at Cowlitz Falls Dam, Washington, 2013
Collection of juvenile salmonids at Cowlitz Falls Dam is a critical part of the effort to restore salmon in the upper Cowlitz River because the majority of fish that are not collected at the dam pass downstream and enter a large reservoir where they become landlocked and lost to the anadromous fish population. However, the juvenile fish collection system at Cowlitz Falls Dam has failed to achieveAuthorsTobias J. Kock, Theresa L. Liedtke, Brian K. Ekstrom, Ryan G. Tomka, Dennis W. RondorfEvaluation of the behavior and movement patterns of adult coho salmon and steelhead in the North Fork Toutle River, Washington, 2005-2009
The 1980 eruption of Mount St. Helens severely affected the North Fork Toutle River (hereafter Toutle River), Washington, and threatened anadromous salmon (Oncorhynchus spp.) populations in the basin. The Toutle River was further affected in 1989 when a sediment retention structure (SRS) was constructed to trap sediments in the upper basin. The SRS completely blocked upstream volitional passage, sAuthorsTheresa L. Liedtke, Tobias J. Kock, Dennis W. RondorfReview of a model to assess stranding of juvenile salmon by ship wakes along the Lower Columbia River, Oregon and Washington
Long period wake waves from deep draft vessels have been shown to strand small fish, particularly juvenile Chinook salmon Oncorhynchus tschawytcha, in the lower Columbia River (LCR). The U.S. Army Corps of Engineers is responsible for maintaining the shipping channel in the LCR and recently conducted dredging operations to deepen the shipping channel from an authorized depth of 40 feet(ft) to an aAuthorsTobias J. Kock, John M. Plumb, Noah S. AdamsSnake River fall Chinook salmon life history investigations: Annual report 2011 (April 2011 - March 2012)
Executive Summary Chapter One – This chapter was published in the Transactions of the American Fisheries Society in 2012. We conducted a three-year radiotelemetry study in the lower Snake River to answer the questions: do fall Chinook salmon juveniles pass dams during winter when bypass systems and structures designed to prevent mortality are not operated; does downstream movement rate vary annualAuthorsKenneth F. Tiffan, William P. Connor, Brian J. Bellgraph, Tobias J. Kock, Frank Mullins, R. Kirk Steinhorst, Helena E. Christiansen, Stephen D. McCormick, Lori A. Ortega, Kathleen M. Carter, Evan V. Arntzen, Katherine J.C. Klett, Z. Daniel Deng, Tylor K. Abel, Timothy J. Linley, Valerie I. Cullinan, Scott J. St John, John M. Erhardt, Brad K. Bickford, Amanda Schmidt, Tobyn N. Rhodes - News
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