Invasive Brown Trout Population Assessment & Suppression Feasibility Pilot Study 2016

Salmonid Research, Monitoring, and Evaluation (RM&E)

Project IDHoopa2016 Inv Br Trout
Recovery DomainsN CA - S Oregon
Start Date02/01/2016
End Date03/31/2017
Last Edited05/08/2024
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This project involved combining the age, survival rate, diet proportions, population estimates, and growth rates of Trinity River Brown Trout based on three years of field work into a bioenergetics simulation. The output of that simulation was the biomass of four prey categories consumed over the course of a year. The findings were written up as a masters thesis with recommendations for future suppression efforts to ameliorate the impact Brown Trout have on the native fishes of the Trinity River, including endagered SONCC Coho salmon.

Project Benefit    

Results from this assessment, detailed in the final progress report, will be used to illuminate the magnitude of the problem and capture success rates will inform suppression feasibility while implementing a one-time suppression treatment via fish collections. This project would be conducted in close coordination with NOAA, USFWS, CDFW, the Yurok Tribe, and Humboldt State University. This project was conducted primarily by Justin Alvarez, a tribal member and employee of the Hoopa Valley Tribal Fisheries Department, and Dr. Darren Ward at Humboldt State University, as part of Justins requirements for a Master of Science (major in Natural Resources) degree from Humboldt State University.


Metric Completed Originally

Funding Details

Report Total:$71,016

Project Map


Trinity River below Lewiston Dam to confluence of North Fork Trinity River    

  • Worksite Identifier: Trinity River below Lewiston Dam to confluence of North Fork Trinity River
  • Start Date:
  • End Date:
Area Description

No Area Description data was found for this worksite.

Location Information

  • Basin: Klamath (180102)
  • Subbasin: Trinity (18010211)
  • Watershed: Weaver Creek-Trinity River (1801021107)
  • Subwatershed:
  • State: California
  • Recovery Domain: N CA - S Oregon
  • Latitude: 40.72402849612468
  • Longitude: -122.80275821685412


  • Southern Oregon/Northern California Coast Coho Salmon ESU




  • E.0 Salmonid Research, Monitoring, and Evaluation (RM&E)Y (Y/N)
    •      . . E.0.a RM&E Funding 71,016.00
    •      . . E.0.b
      Complement habitat restoration project
      Trinity River Restoration Program
    •      . . E.0.c
      Project identified in a plan or watershed assessment.
      SONCC Recovery Plan
    •      . . E.0.d.1 Number of Cooperating Organizations 7
    •      . . E.0.d.2
      Name Of Cooperating Organizations.
      Bureau of Reclamation, US Fish and Wildlife Service, National Marine Fisheries Service, US Forest Service, Yurok Tribe, Trinity County, California Department of Natural Resources
    •      . . E.0.e.1 Number of reports prepared 1
    •      . . E.0.e.2
      Name Of Report
      Alvarez, Justin S., "Abundance, growth, and predation by non-native brown trout in the Trinity River, CA" (2017). Theses. 47.
    •      . . E.2 ResearchY (Y/N)
      •      . . . . E.2.a Research Funding 71,016.00
      •      . . . . E.2.b.1 Modeling and data analysisY (Y/N)
        •      . . . . . . E.2.b.1.a
          Key issues addressed by modeling and data analysis research
          Impact of non-native brown trout (Salmo trutta) on native anadromous salmonids including SONCC.