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
Range expansion of an exotic Siberian prawn to the Lower Snake River
Effects of hydropower operations on spawning habitat, rearing habitat, and stranding/entrapment mortality of Fall Chinook Salmon in the Hanford Reach of the Columbia River
Effects of summer flow augmentation on the migratory behavior and survival of juvenile Snake River fall Chinook salmon. Annual report 2005
Food habits of Juvenile American Shad and dynamics of zooplankton in the lower Columbia River
As many as 2.4 million adult American shad annually pass John Day Dam, Columbia River to spawn upriver, yet food web interactions of juvenile shad rearing in John Day Reservoir are unexplored. We collected zooplankton and conducted mid-water trawls in McNary (June-July) and John Day reservoirs (August-November) from 1994 through 1996 during the outmigration of subyearling American shad and Chinook
Effects of hydropower operations on spawning habitat, rearing habitat, and standing/entrapment mortality of fall Chinook salmon in the Hanford Reach of the Columbia River
Crims Island habitat restoration in the Columbia River estuary-fisheries monitoring and evaluation, 2004
No abstract available
Predicted changes in subyearling fall Chinook salmon rearing and migratory habitat under two drawdown scenarios for John Day Reservoir, Columbia River
Variables influencing the presence of subyearling fall Chinook salmon in shoreline habitats of the Hanford Reach, Columbia River
Biological science in Oregon
Two alternative juvenile life history types for fall Chinook salmon in the Snake River basin
Diel spawning behavior of chum salmon in the Columbia River
Measuring nighttime spawning behavior of chum salmon using a dual-frequency identification sonar (DIDSON)
Science and Products
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Filter Total Items: 108
Range expansion of an exotic Siberian prawn to the Lower Snake River
The introduction of non-native plant and animal species in aquatic systems is of increasing concern because of their potentially negative ecological and economic impacts (Sytsma et al. 2004). There are many examples of food web repercussions resulting from non-native invertebrate introductions. For example, in Flathead Lake, Montana, the kokanee salmon (Oncorhynchus nerka) population crashed afterAuthorsCraig A. Haskell, Rex D. Baxter, Kenneth F. TiffanEffects of hydropower operations on spawning habitat, rearing habitat, and stranding/entrapment mortality of Fall Chinook Salmon in the Hanford Reach of the Columbia River
No abstract available.AuthorsDonald R. Anglin, Steven L. Haeseker, Joseph J. Skalicky, Howard Schaller, Kenneth F. Tiffan, James R. Hatten, Paul Hoffarth, John Nugent, David Benner, Marv YoshinakaEffects of summer flow augmentation on the migratory behavior and survival of juvenile Snake River fall Chinook salmon. Annual report 2005
This report summarizes results of research activities conducted in 2004 and years previous to aid in the management and recovery of fall Chinook salmon Oncorhynchus tshawytscha in the Columbia River basin. For detailed summaries, we refer the reader to the abstracts given on the second page of each chapter. The Annual Reporting section includes information provided to fishery managers in-season anAuthorsKenneth F. Tiffan, William P. ConnorFood habits of Juvenile American Shad and dynamics of zooplankton in the lower Columbia River
As many as 2.4 million adult American shad annually pass John Day Dam, Columbia River to spawn upriver, yet food web interactions of juvenile shad rearing in John Day Reservoir are unexplored. We collected zooplankton and conducted mid-water trawls in McNary (June-July) and John Day reservoirs (August-November) from 1994 through 1996 during the outmigration of subyearling American shad and Chinook
AuthorsC. A. Haskell, K.F. Tiffan, D.W. RondorfEffects of hydropower operations on spawning habitat, rearing habitat, and standing/entrapment mortality of fall Chinook salmon in the Hanford Reach of the Columbia River
This report describes research conducted primarily in 2003 and 2004 to evaluate the effects of upstream dam operations on spawning and rearing conditions for fall Chinook salmon, Oncorhynchus tshawytscha, in the Hanford Reach of the Columbia River. Results from habitat modeling tasks which continued in 2005 and 2006 are also included in this report. This study is focused on the effects of streamflAuthorsDonald R. Anglin, Steven L. Haeseker, Joseph J. Skalicky, Howard Schaller, Kenneth F. Tiffan, James R. Hatten, Paul Hoffarth, John Nugent, David Benner, Marv YoshinakaCrims Island habitat restoration in the Columbia River estuary-fisheries monitoring and evaluation, 2004
No abstract available
AuthorsC. A. Haskell, K.F. Tiffan, R.C. Koch, D.W. RondorfPredicted changes in subyearling fall Chinook salmon rearing and migratory habitat under two drawdown scenarios for John Day Reservoir, Columbia River
We evaluated the potential effects of two different drawdown scenarios on rearing and migration habitat of subyearling fall Chinook salmon Oncorhynchus tshawytscha in John Day Reservoir on the Columbia River. We compared habitats at normal operating pool elevation with habitats at drawdown to spillway crest elevation and drawdown to the historical natural river elevation for two flows (4,417 and 8AuthorsK.F. Tiffan, R.D. Garland, D.W. RondorfVariables influencing the presence of subyearling fall Chinook salmon in shoreline habitats of the Hanford Reach, Columbia River
Little information currently exists on habitat use by subyearling fall Chinook salmon Oncorhynchus tshawytscha rearing in large, main-stem habitats. We collected habitat use information on subyearlings in the Hanford Reach of the Columbia River during May 1994 and April-May 1995 using point abundance electrofishing. We analyzed measures of physical habitat using logistic regression to predict fishAuthorsK.F. Tiffan, L.O. Clark, R.D. Garland, D.W. RondorfBiological science in Oregon
Fishing is an important part of Oregon's culture. The Western Fisheries Research Center (WFRC) has been conducting research in Oregon for many years to provide information that can be used by managers to help keep fish and other parts of the ecosystem healthy. Below are examples of some of WFRC's studies.AuthorsLyman ThorsteinsonTwo alternative juvenile life history types for fall Chinook salmon in the Snake River basin
Fall Chinook salmon Oncorhynchus tshawytscha in the Snake River basin were listed under the Endangered Species Act in 1992. At the time of listing, it was assumed that fall Chinook salmon juveniles in the Snake River basin adhered strictly to an ocean-type life history characterized by saltwater entry at age 0 and first-year wintering in the ocean. Research showed, however, that some fall ChinookAuthorsW.P. Connor, J.G. Sneva, K.F. Tiffan, R.K. Steinhorst, D. RossDiel spawning behavior of chum salmon in the Columbia River
We conducted a study during 2003 in a side channel of the Columbia River downstream of Bonneville Dam to describe the diel spawning behavior of wild chum salmon Oncorhynchus keta. We collected observational data on 14 pairs of chum salmon using a dual-frequency identification sonar. Spawners of both genders were observed chasing intruders during nighttime and daytime as nests were constructed. RegAuthorsK.F. Tiffan, D.W. Rondorf, J.J. SkalickyMeasuring nighttime spawning behavior of chum salmon using a dual-frequency identification sonar (DIDSON)
The striking body coloration and morphology that Pacific salmon display during spawning coupled with elaborate courtship behaviors suggest that visual cues are important during their reproductive period. To date, virtually all existing information on chum salmon (Oncorhynchus keta) spawning behavior has been derived from studies conducted during the daytime, and has contributed to the assumption tAuthorsK.F. Tiffan, D.W. Rondorf - News