Brian Ekstrom
Science and Products
Behavior and movement of adult winter steelhead (Oncorhynchus mykiss) in the upper Cowlitz River Basin, Washington, 2017–18
Executive SummaryA 2-year radiotelemetry study was completed to monitor the movements of adult winter steelhead (Oncorhynchus mykiss) in the upper Cowlitz River Basin. A reintroduction program was established to restore healthy and harvestable populations of steelhead because volitional access to the area was blocked in the 1960s after...
Liedtke, Theresa L.; Kock, Tobias J.; Hansen, Amy C.; Ekstrom, Brian K.; Tomka, Ryan G.
Evaluation of water temperature effects on adult sockeye salmon (Oncorhynchus nerka) behavior in the Yakima River, Washington, 2019
A study was conducted in the lower Yakima River, Washington, during June–October 2019 to evaluate water temperature effects on adult sockeye salmon (Oncorhynchus nerka) behavior. A total of 60 sockeye salmon adults were tagged with radio transmitters and monitored during the study. Fourteen of the fish were collected and tagged at Prosser Dam in...
Kock, Tobias J.; Evans, Scott D.; Hansen, Amy C.; Ekstrom, Brian K.; Visser, Richard; Saluskin, Brian; Hoffarth, Paul
Distribution of adult Chinook salmon (Oncorhynchus tshawytscha) in relation to water temperatures, Lake Scanewa, Cowlitz River, Washington, 2012
A trap-and-haul program is operated to move anadromous Pacific salmon (Oncorhynchus spp.) around dams and reservoirs in the Cowlitz River basin, Washington. The primary release site for adult fish is in Lake Scanewa, a small reservoir created by Cowlitz Falls Dam, the uppermost dam in the basin. Releases in the reservoir are terminated when...
Kock, Tobias J.; Ekstrom, Brian K.; Liedtke, Theresa L.
Adult sockeye salmon (Oncorhynchus nerka) behavior and movement from Roza Dam to Cle Elum Dam, Washington, 2018
An evaluation was conducted to describe adult sockeye salmon (Oncorhynchus nerka) upstream movement patterns from Roza Dam to Cle Elum Dam in the Yakima Basin, Washington. Sockeye salmon adults that arrive at Roza Dam are currently trapped and transported upstream of Cle Elum Dam because upstream fish-passage facilities are not currently in place...
Kock, Tobias J.; Evans, Scott D.; Ekstrom, Brian K.; Hansen, Amy C.
Behavior patterns and fates of adult steelhead, Chinook salmon, and coho salmon released into the upper Cowlitz River Basin, 2005–09 and 2012, Washington
A multiyear radiotelemetry evaluation was conducted to monitor adult steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) behavior and movement patterns in the upper Cowlitz River Basin. Volitional passage to this area was eliminated by dam construction in the mid-1960s, and a reintroduction program began...
Kock, Tobias J.; Ekstrom, Brian K.; Liedtke, Theresa L.; Serl, John D.; Kohn, Mike
Evaluation 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...
Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Hurst, William
Evaluation 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...
Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Gleizes, Chris; Dammers, Wolf
Evaluation 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...
Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.
Behavior and movement of adult summer steelhead following collection and release, lower Cowlitz River, Washington, 2012--2013
Executive SummaryHistorically, adult summer steelhead Oncorhynchus mykiss returning to hatcheries on the lower Cowlitz River were sometimes transported and released in the river (recycled) to provide additional angling opportunity for the popular sport fishery in the basin. However, this practice has not been used in recent years because of...
Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Rondorf, Dennis W.; Gleizes, Chris; Dammers, Wolf; Gibson, Scott; Murphy, Jamie
Behavior and passage of juvenile salmonids during the evaluation of a behavioral guidance structure at Cowlitz Falls Dam, Washington, 2011
Executive Summary A radiotelemetry evaluation was conducted during April–October 2011 to describe movement patterns, forebay behavior, and passage of juvenile steelhead, coho salmon, and Chinook salmon at Cowlitz Falls Dam, Washington. The primary focus of the study was to describe fish behavior near a behavioral guidance structure (BGS) and...
Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.
Behavior and movement of formerly landlocked juvenile coho salmon after release into the free-flowing Cowlitz River, Washington
Formerly landlocked Coho Salmon (Oncorhynchus kisutch) juveniles (age 2) were monitored following release into the free-flowing Cowlitz River to determine if they remained in the river or resumed seaward migration. Juvenile Coho Salmon were tagged with a radio transmitter (30 fish) or Floy tag (1050 fish) and their behavior was monitored in the...
Kock, Tobias J.; Henning, Julie A.; Liedtke, Theresa L.; Royer, Ida M.; Ekstrom, Brian K.; Rondorf, Dennis W.
Evaluation of angler effort and harvest of rainbow trout (Oncorhynchus mykiss), Lake Scanewa, Washington, 2010
A creel evaluation was conducted in Lake Scanewa, a reservoir on the Cowlitz River, to monitor catch rates of rainbow trout (Oncorhynchus mykiss) and determine if the trout fishery was having negative impacts on juvenile anadromous salmon (Oncorhynchus spp.) in the system. The trout fishery, which is supported by releases of 20,000 fish (2 fish...
Liedtke, Theresa L.; Kock, Tobias J.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.