Hells Canyon on the Snake River.
Kenneth Tiffan
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
Science and Products
Snake River Fall Chinook Salmon Research - Cooperator Publications
Snake River Fall Chinook Salmon Research
Hells Canyon on the Snake River.
Beam trawling in Lower Granite Reservoir on the Snake River.
Beam trawling in Lower Granite Reservoir on the Snake River.
Juvenile Snake River fall Chinook salmon.
Juvenile Snake River fall Chinook salmon.
First investigations on lamprey responses to elevated total dissolved gas exposure and risk of gas bubble trauma
Monitoring native nonsalmonids for the incidence of gas bubble trauma downstream of Snake and Columbia River dams during the spring spill season, 2022
Backpack electrofishing does not contribute to external signs of gas bubble trauma in sculpins
Snake River fall Chinook salmon research and monitoring
Monitoring native, resident nonsalmonids for the incidence of gas bubble trauma downstream of Snake and Columbia River Dams, 2021
Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River Fall Chinook salmon ESU
Lower Granite Reservoir biological monitoring at 2015 disposal site
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
Science and Products
- Science
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... - Multimedia
Hells Canyon on the Snake River
Hells Canyon on the Snake River.
Hells Canyon on the Snake River.
Beam trawling in Lower Granite Reservoir on the Snake RiverBeam trawling in Lower Granite Reservoir on the Snake RiverBeam trawling in Lower Granite Reservoir on the Snake River.
Beam trawling in Lower Granite Reservoir on the Snake River.
Juvenile Snake River fall Chinook salmonJuvenile Snake River fall Chinook salmon.
Juvenile Snake River fall Chinook salmon.
- Publications
Filter Total Items: 108
First investigations on lamprey responses to elevated total dissolved gas exposure and risk of gas bubble trauma
A flexible spill program in the federal Columbia River power system increased the total dissolved gas (TDG) water quality standards (i.e., the gas cap) from 120% to 125%. Spill is used to pass juvenile salmon (Oncorhynchus spp.) over dams, but it can generate elevated TDG, and exposed fish can develop gas bubble trauma (GBT) or experience mortality. Juvenile salmon are monitored for GBT through thAuthorsTheresa L. Liedtke, Kenneth Tiffan, Lisa K. Weiland, Brian K. EkstromMonitoring native nonsalmonids for the incidence of gas bubble trauma downstream of Snake and Columbia River dams during the spring spill season, 2022
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 nonsalmonids for gas bubble trauma (GBT) became a requirement. The primary objective of this work was to measure the incidence and severity of GBT inAuthorsKenneth Tiffan, Brad Liedtke, Dalton Dirk Lebeda, Scott Louis Benson, Joe J. WarrenBackpack 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 saturatiAuthorsKenneth Tiffan, Nicole Joy EllerSnake River fall Chinook salmon research and monitoring
In 2021, the U.S. Geological Survey (USGS) focused adult salmon survey efforts in the Snake River on deepwater redd searches and fish collection for parentage-based tagging (PBT) analyses. We use used a boat-mounted underwater video camera to count 93 deepwater redds at 17 of the 28 sites surveyed. Redd depths averaged 3.9 m. In conjunction with the Idaho Power Company, we collected genetic sampleMonitoring 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 incidencAuthorsKenneth Tiffan, Collin Smith, Nicole Joy Eller, Joe J. WarrenResearch, 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 evolutionary significant unit (ESU) that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2020 in response to U.S. Endangered Species Act recovery efforts and other federally mandated actions. This annual report focuses on changes in population abundance and habitat use by natural- aAuthorsKenneth Tiffan, Peter H. Barry, Dalton Hance, John Plumb, Brad Bickford, Tobyn Rhodes, Kenneth G. King, Dalton Dirk Lebeda, Rulon J. Hemingway, John HargroveLower Granite Reservoir biological monitoring at 2015 disposal site
No abstract available.AuthorsRulon J Hemingway, Kenneth TiffanPerformance 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‐mmAuthorsKenneth Tiffan, Tobyn Rhodes, Brad Bickford, Dalton Dirk Lebeda, William P. Connor, Frank L. MullinsImpact 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 subyearAuthorsKenneth Tiffan, John M Erhardt, Rulon J. Hemingway, Brad Bickford, Tobyn RhodesResearch, 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 evAuthorsKenneth Tiffan, Ian Jezorek, Russell PerrySnake 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 ofAuthorsKenneth F. Tiffan, Paul M. Chittaro, Brian P. Kennedy - News