John Erhardt

I received a B.S. degree in environmental sciences from the University of Toledo and a M.S. degree in fishery resources from the University of Idaho. As part of my Master’s research, I assessed the effects of ongoing harvest closures on demographic rates and life history of bull trout.  Prior to joining USGS in 2009, I worked for the Idaho Department of Fish and Game and U.S. Forest Service.



M.S. 2010. Fisheries Resources, University of Idaho, Bozeman, MT

B.S. 2003. Environmental Sciences, University of Toledo, Toledo, OH


Research Interests:                                    

I have broad interests in ecology and life history of salmonids, as they relate to conservation and management.  My research experience has primarily involved assessing migratory behavior and life history variability using telemetry and assessing population vital statistics using management models.  Most recently, my research has focused on understanding the effects of food web alterations from non-native species introductions on the growth and survival of salmonids.  This research has led to a better understanding of demographic rates and environmental requirements for different life history strategies and environments, which is central to managing fish populations for sustainability and restoring anadromous fish stocks.    



2009 to Present – Fish Biologist, U.S. Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA

2003-2008 - Fishery Technician, Idaho Department of Fish and Game


Honors, Awards, Recognition, Elected Memberships:

American Fisheries Society Certified Fisheries Professional


Professional Societies:

American Fisheries Society