Tobyn Rhodes
Science and Products
Performance 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...
Tiffan, Kenneth; Rhodes, Tobyn; Bickford, Brad; Lebeda, Dalton Dirk; Connor, William P.; Mullins, Frank L. Impact 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...
Tiffan, Kenneth; Erhardt, John M; Hemingway, Rulon J.; Bickford, Brad; Rhodes, Tobyn Research, 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 ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2018 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...
Tiffan, Kenneth; Perry, Russell; Plumb, John; Hance, Dalton; Bickford, Brad; Rhodes, Tobyn Fall Chinook salmon (Oncorhynchus tshawytscha), sand roller (Percopsis transmontana), and smallmouth bass (Micropterus dolomieu) interactions in a Snake River reservoir: A tale of three species
We studied some of the relationships between federally listed fall Chinook Salmon, Oncorhynchus tshawytscha, endemic Sand Roller, Percopsis transmontana, and non-native Smallmouth Bass, Micropterus dolomieu, in Lower Granite Reservoir on the Snake River. Because of its recent reappearance and population increase, the Sand Rollers...
Hemingway, Rulon J.; Tiffan, Kenneth F.; Erhardt, John M.; Rhodes, Tobyn N.; Bickford, Brad K. Research, 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 ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2017 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...
Tiffan, Kenneth; Plumb, John M.; Perry, Russell W.; Erhardt, John; Hemingway, Rulon J.; Bickford, Brad; Rhodes, Tobyn N.; Connor, William P.; Mullins, Frank L. Smallmouth bass predation on subyearling fall Chinook salmon in Lower Granite Reservoir, 2016–2017
Predation by nonnative fishes is one factor that has been implicated in the decline of juvenile salmonids in the Pacific Northwest. Impoundment of much of the Snake and Columbia Rivers has altered food webs and created habitat favorable for species such as smallmouth bass Micropterus dolomieu. Smallmouth bass are common throughout the Columbia...
Erhardt, John M.; Tiffan, Kenneth F.; Hemingway, Rulon J.; Bickford, Brad K.; Rhodes, Tobyn N. Ecology of the Sand Roller (Percopsis transmontana) in a lower Snake River Reservoir, Washington
The Sand Roller (Percopsis transmontana), has not been abundant in the Snake River since it was first found in the system in the 1950s, but its population has apparently increased in recent years. As a result, we initiated a study to better understand its ecology in habitats of Lower Granite Reservoir. From November 2014 to October 2015, Sand...
Tiffan, Kenneth F.; Erhardt, John M.; Rhodes, Tobyn N.; Hemingway, Rulon J. Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River Fall Chinook Salmon ESU, 1/1/2016 - 12/31/2016
The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2016 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...
Connor, William P.; Mullins, Frank L.; Tiffan, Kenneth F.; Plumb, John M.; Perry, Russell W.; Erhardt, John M.; Hemingway, Rulon J.; Bickford, Brad K.; Rhodes, Tobyn N. Snake River Fall Chinook Salmon life history investigations
Predation by nonnative fishes is one factor that has been implicated in the decline of juvenile salmonids in the Pacific Northwest. Impoundment of much of the Snake and Columbia rivers has altered food webs and created habitat favorable for species such as Smallmouth Bass Micropterus dolomieu. Smallmouth Bass are common throughout the Columbia...
Erhardt, John M.; Bickford, Brad K.; Hemingway, Rulon J.; Rhodes, Tobyn N.; Tiffan, Kenneth F. Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook salmon ESU, 1/1/2014 - 12/31/2014
The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2014 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...
Connor, William P.; Mullins, Frank L.; Tiffan, Kenneth F.; Perry, Russell W.; Erhardt, John M.; St John, Scott J.; Bickford, Brad K.; Rhodes, Tobyn N. Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook salmon ESU, 1/1/2012 – 12/31/2013: Annual report, 1991-029-00
The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2014 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...
Connor, William P.; Mullins, Frank; Tiffan, Kenneth F.; Perry, Russell W.; Erhardt, John M.; St. John, Scott J.; Bickford, Brad K.; Rhodes, Tobyn N. Snake 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...
Tiffan, Kenneth F.; Connor, William P.; Bellgraph, Brian J.; Kock, Tobias J.; Mullins, Frank; Steinhorst, R. Kirk; Christiansen, Helena E.; McCormick, Stephen D.; Ortega, Lori A.; Carter, Kathleen M.; Arntzen, Evan V.; Klett, Katherine J.C.; Deng, Z. Daniel; Abel, Tylor K.; Linley, Timothy J.; Cullinan, Valerie I.; St John, Scott J.; Erhardt, John M.; Bickford, Brad K.; Schmidt, Amanda; Rhodes, Tobyn N.