Bull trout population assessment in northeastern Oregon: a template for recovery planning.


2002-2012 (ongoing)


The goal of this project is to provide data and conservation assessment tools to aid the U.S. Fish and Wildlife Service’s efforts to determine management actions necessary for recovery of bull trout, a species listed as Threatened under the Endangered Species Act. Each summer, researchers systematically capture and mark bull trout with unique tags and then re-sight marked individuals during subsequent sampling events at various locations throughout the watershed. Additional resights occur at passive in-stream antenna arrays, located throughout the river system, which allows us to track movement of marked fish. Collecting data on several populations across consecutive years has allowed us to provide critical information on bull trout abundance, trend, vital rates, habitat needs, and movement patterns, and compare how these vary between different life-stages. Data from this study is currently being used to help build a population viability model to assess how elimination of current threats can help protect bull trout populations across the species’ range.


  • US Fish and Wildlife Service, US Geological Survey - Utah Cooperative Fish and Wildlife Research Unit (in-kind)


  • Phaedra Budy, Principle Investigator, USGS – UCFWRU, USU- Dept. of Watershed Sciences
  • Gary P. Thiede, Fishery Biologist, USU- Dept. of Watershed Sciences
  • Tracy Bowerman, Graduate Research Assistant (PhD), USU- WATS (expected graduation, 2012)


Al-Chokhachy, R. and P. Budy. 2008.
Demographic characteristics, population structure, and vital rates of a fluvial population of bull trout in Oregon.
Transactions of the American Fisheries Society 137: 1709:1722.

Al- Chokhachy, R., P. Budy, and M. Conner. 2009.
Detecting declines in the abundance of a bull trout (Salvelinus confluentus) population: understanding the accuracy, precision and costs of our efforts.
Canadian Journal of Fisheries and Aquatic Sciences 66: 649-658.


Budy, P., L. B. Tennant, T. Bowerman, and G.P. Thiede. 2011.
Bull trout population assessment in northeastern Oregon: a template for recovery planning.
2010 Annual Progress Report to US Fish and Wildlife Service. UTCFWRU 2011 (5):1-90.



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