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
The effects of juvenile American shad planktivory on zooplankton production in Columbia River food webs
Downstream movement of fall Chinook salmon juveniles in the lower Snake River reservoirs during winter and early spring
Snake River fall Chinook salmon life history investigations: Annual report 2010
Seasonal use of shallow water habitat in the Lower Snake River reservoirs by juvenile fall Chinook salmon
Estimating and predicting collection probability of fish at dams using multistate modeling
Project Planning for Cougar Dam during 2010
Crims Island-Restoration and monitoring of juvenile salmon rearing habitat in the Columbia River Estuary, Oregon, 2004-10
Distinguishing between natural and hatchery Snake River fall Chinook salmon subyearlings in the field using body morphology
Snake River Fall Chinook Salmon life history investigations annual report, 2009
Snake River fall Chinook salmon life history investigations, annual report 2008
Diel behavior of rearing fall Chinook salmon
Quantifying the behavioral response of spawning chum salmon to elevated discharges from Bonneville Dam, Columbia River, USA
Chum salmon Oncorhynchus keta that spawn in main-stem habitats below Bonneville Dam on the Columbia River, USA, are periodically subjected to elevated discharges that may alter spawning behaviour. We investigated behavioural responses of spawning chum salmon to increased water velocities associated with experimental increases in tailwater elevation using acoustic telemetry and a dual-frequency ide
Science and Products
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The effects of juvenile American shad planktivory on zooplankton production in Columbia River food webs
Columbia River reservoirs support a large population of nonnative American Shad Alosa sapidissima that consume the zooplankton that native fishes also rely on. We hypothesized that the unprecedented biomass of juvenile American Shad in John Day Reservoir is capable of altering the zooplankton community if these fish consume a large portion of the zooplankton production. We derived taxon-specific eAuthorsCraig A. Haskell, Kenneth F. Tiffan, Dennis W. RondorfDownstream movement of fall Chinook salmon juveniles in the lower Snake River reservoirs during winter and early spring
We conducted a 3-year radiotelemetry study in the lower Snake River to (1) determine whether juvenile fall Chinook salmon Oncorhynchus tshawytscha pass dams during winter, when bypass systems and structures designed to prevent mortality are not operated; (2) determine whether downstream movement rate varies annually, seasonally, and from reservoir to reservoir; and (3) identify some of the factorsAuthorsKenneth F. Tiffan, Tobias J. Kock, William P. Connor, Frank Mullins, R. Kirk SteinhorstSnake River fall Chinook salmon life history investigations: Annual report 2010
This report summarizes three research activities conducted in 2010-2011. The first was a radiotelemetry study conducted in the lower Clearwater River. The second was a hydroacoustic study conducted in Lower Granite and Little Goose reservoirs. The third was an analysis of covariates affecting juvenile fall Chinook salmon survival and behavior. In 2010, we used radiotelemetry to evaluate the migratAuthorsKenneth F. Tiffan, William P. Connor, Rebecca A. Buchanan, Scott J. St John, John M. Erhardt, Craig A. HaskellSeasonal use of shallow water habitat in the Lower Snake River reservoirs by juvenile fall Chinook salmon
The U.S. Army Corps of Engineers (COE) is preparing a long term management plan for sediments that affect the authorized project purposes of the Lower Granite, Little Goose, Lower Monumental, and Ice Harbor reservoirs (hereafter, the lower Snake River reservoirs), and the area from the mouth of the Snake River to Ice Harbor Dam. We conducted a study from spring 2010 through winter 2011 to describeAuthorsKenneth F. Tiffan, William P. ConnorEstimating and predicting collection probability of fish at dams using multistate modeling
Dams can be equipped with a bypass that routes a portion of the fish that enter the turbine intakes away from the powerhouse into flumes, where they can be counted. Daily passage abundance can be estimated by dividing the number of fish counted in the bypass by the sampling rate and then dividing the resulting quotient by the collection probability (i.e., the proportion of the fish population passAuthorsJohn M. Plumb, William P. Connor, Kenneth F. Tiffan, Christine M. Moffitt, Russell W. Perry, Noah S. AdamsProject Planning for Cougar Dam during 2010
Cougar Dam is a 158 m-tall, rock fill dam located about 63 km east of Springfield, Oregon. Completed in 1963, the dam is owned and operated by the U.S. Army Corps of Engineers (USACE). It impounds Cougar Reservoir, which is 9.7 km long, has a surface area of 518 ha, and is predominately used for flood control. The pool elevation typically ranges from a maximum conservation pool of 515 m (1,690 ft)AuthorsCraig A. Haskell, Kenneth F. TiffanCrims Island-Restoration and monitoring of juvenile salmon rearing habitat in the Columbia River Estuary, Oregon, 2004-10
Under the 2004 Biological Opinion for operation of the Federal Columbia River Power System released by the National Marine Fisheries Service, the U.S. Army Corps of Engineers (USACE), the Bonneville Power Administration (BPA), and the Bureau of Reclamation (Reclamation) were directed to restore more than 4,047 hectares (10,000 acres) of tidal marsh in the Columbia River estuary by 2010. RestoratioAuthorsCraig A. Haskell, Kenneth F. TiffanDistinguishing between natural and hatchery Snake River fall Chinook salmon subyearlings in the field using body morphology
We used body morphology to distinguish between natural‐ and hatchery‐origin subyearling fall Chinook salmon Oncorhynchus tshawytscha in rearing areas of the Snake River and at a downstream dam during seaward migration. Using subjective eye and body shape characteristics, field personnel correctly classified 88.9–100% of natural subyearlings (N = 626) and 90.0–100% of hatchery subyearlings (N = 867AuthorsKenneth F. Tiffan, W.P. ConnorSnake River Fall Chinook Salmon life history investigations annual report, 2009
In 2009, we used radio and acoustic telemetry to evaluate the migratory behavior, survival, mortality, and delay of subyearling fall Chinook salmon in the Clearwater River and Lower Granite Reservoir. We released a total of 1,000 tagged hatchery subyearlings at Cherry Lane on the Clearwater River in mid August and we monitored them as they passed downstream through various river and reservoir reacAuthorsKenneth F. Tiffan, William P. Connor, Brian J. Bellgraph, Rebecca A. BuchananSnake River fall Chinook salmon life history investigations, annual report 2008
In 2009, we used radio and acoustic telemetry to evaluate the migratory behavior, survival, mortality, and delay of subyearling fall Chinook salmon in the Clearwater River and Lower Granite Reservoir. We released a total of 1,000 tagged hatchery subyearlings at Cherry Lane on the Clearwater River in mid August and we monitored them as they passed downstream through various river and reservoir reacAuthorsKenneth F. Tiffan, William P. Connor, Brian J. Bellgraph, Rebecca A. BuchananDiel behavior of rearing fall Chinook salmon
In fisheries science, habitat use is often inferred when fish are sampled or observed in a particular location. Physical habitat is typically measured where fish are found, and thus deemed important to habitat use. Although less common, a more informative approach is to measure or observe fish behavior within given habitats to more thoroughly assess their use of those locations. While this approacAuthorsKenneth F. Tiffan, Tobias J. Kock, Joseph J. SkalickyQuantifying the behavioral response of spawning chum salmon to elevated discharges from Bonneville Dam, Columbia River, USA
Chum salmon Oncorhynchus keta that spawn in main-stem habitats below Bonneville Dam on the Columbia River, USA, are periodically subjected to elevated discharges that may alter spawning behaviour. We investigated behavioural responses of spawning chum salmon to increased water velocities associated with experimental increases in tailwater elevation using acoustic telemetry and a dual-frequency ide
AuthorsK.F. Tiffan, C. A. Haskell, T.J. Kock - News