Future Management Strategy
The Malheur River Bull Trout Technical Advisory Committee
is working on an effective eradication strategy:
Proposal: Use a common chemical piscicide (Rotenone) to remove 100% of the brook trout from High Lake and Upper Lake Creek
This effort would be a ten year intensive, interagency effort involving the construction of fish barriers to maintain the newly created (brook trout free) habitat. Rotenone is a chemical treatment which has been used by fish managers since the 1930's. Managers treat selected stream/lake sections with rotenone (an natural compound which is absorbed through gills and inhibits cellular respiration). Rotenone can be quickly detoxified in headwater streams (often in less than 24 hours) by 1) basic dilution 2) detoxification with potassium permanganate and 3) natural breakdown processes (exposure to sunlight and oxygen).
is working on an effective eradication strategy:
Proposal: Use a common chemical piscicide (Rotenone) to remove 100% of the brook trout from High Lake and Upper Lake Creek
This effort would be a ten year intensive, interagency effort involving the construction of fish barriers to maintain the newly created (brook trout free) habitat. Rotenone is a chemical treatment which has been used by fish managers since the 1930's. Managers treat selected stream/lake sections with rotenone (an natural compound which is absorbed through gills and inhibits cellular respiration). Rotenone can be quickly detoxified in headwater streams (often in less than 24 hours) by 1) basic dilution 2) detoxification with potassium permanganate and 3) natural breakdown processes (exposure to sunlight and oxygen).
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It's all about the timing
The Burns Paiute Tribe has collected data on Upper Malheur freshwater organisms and will use what we've learned to mitigate the effects of the proposed rotenone treatment.
1) Native Fish: prior to rotenone treatment BPT and members of the TAC will capture the native fish in the treatment reach. These fish will be taken to untreated portions of the watershed. 2) Aquatic Insects: BPT has collected data on the insect communities in the streams of the Upper Malheur. This provides the baseline 'healthy' stream community that managers need to maintain. Studies show that insect communities rebound relatively quickly post-rotenone treatment. Though the larval stage of many aquatic insects will be negatively impacted- treatment can be timed to ensure the terrestrial adult life stage of these insects is available to lay eggs and allow for recovery. Upstream insects will also drift downstream allowing for a treated reach to become recolonized. 3) Amphibians: BPT has been actively monitoring amphibians in the Upper Malheur. Treatment timing will occur after the existing amphibians have grown past the tadpole life stage. Rotenone breaks down quickly in streams (often 24 hours) and flexible treatment timing would be planned to avoid impacting amphibians.
1) Native Fish: prior to rotenone treatment BPT and members of the TAC will capture the native fish in the treatment reach. These fish will be taken to untreated portions of the watershed. 2) Aquatic Insects: BPT has collected data on the insect communities in the streams of the Upper Malheur. This provides the baseline 'healthy' stream community that managers need to maintain. Studies show that insect communities rebound relatively quickly post-rotenone treatment. Though the larval stage of many aquatic insects will be negatively impacted- treatment can be timed to ensure the terrestrial adult life stage of these insects is available to lay eggs and allow for recovery. Upstream insects will also drift downstream allowing for a treated reach to become recolonized. 3) Amphibians: BPT has been actively monitoring amphibians in the Upper Malheur. Treatment timing will occur after the existing amphibians have grown past the tadpole life stage. Rotenone breaks down quickly in streams (often 24 hours) and flexible treatment timing would be planned to avoid impacting amphibians.
Flexible Treatment timing to minimize IMpact on the freshwater community |
Pre/Post Treatment monitoring to ensure full ecological recovery |
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Common Questions:
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Why not continue to electrofish?
As discussed in Current Management BPT electrofishing efforts paired with population studies show that mechanical removal efforts can not fully eradicate brook trout. 1) Complex habitat allows for many fish to avoid capture 2) Electrofishing is labor intensive and costly when compared with a rotenone treatment 3) The field season is limited and 4) Age 0 fish avoid capture. It is difficult to target and effectively capture young trout. BPT continues to remove brook trout using electrofishing, but you can see by the 2019 results- brook trout still dominate lower Lake Creek. 
Lake Creek is a hot spot selected for brook trout removal efforts.
In this figure you see the relative abundance of all fish encountered during the 2019 field season for lower Lake Creek (downstream of Lake Creek Falls). Upstream of the falls is the seed source for brook trout (they are the only fish species) and is entirely electroshocked. Mechanical removal efforts are working to suppress brook trout but rotenone will allow for the recovery of native fish. |
Is it worth it?
YES, scientists out of the Rocky Mountain Research Station have been monitoring stream temperatures throughout the Pacific Northwest. With their robust datasets they have been able to effectively model future stream temperatures anticipating the effects of climate change. Groundwater fed, headwater streams (like the streams in the Upper Malheur) hold the greatest potential to remain cold enough for salmonids - especially if managers focus restoration efforts on these systems. 
Future summer (August) mean temperatures projected for the Upper Malheur Basin
NorWeST scenarios: Isaak, D.J.; Wenger, S.J.; Peterson, E.E.; Ver Hoef, J.M.; Hostetler, S.W.; Luce, C.H.; Dunham, J.B.; Kershner, J.L.; Roper, B.B.; Nagel, D.E.; Chandler, G.L.; Wollrab, S.P.; Parkes, S.L.; Horan, D.L. 2016. NorWeST modeled summer stream temperature scenarios for the western U.S. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2016-0033. |
More Information
The Malheur River Bull Trout
Technical Advisory Committee
Contributing Agencies and Participants
Please click on the agency logo to go to their website for more information
Please click on the agency logo to go to their website for more information
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AboutThe Help Native Fish educational materials were created in 2018 to raise awareness about what people who live, work, and recreate near riparian areas can do to help native fish. Currently the materials have been implemented throughout Eastern Oregon.
Our teamThe Technical Advisory Committee of the Malheur River Working Bull Trout Group includes Oregon Department of Fish and Wildlife, Bureau of Reclamation, US Fish and Wildlife Service, the US Forest Service, and the Burns Paiute Tribe. The Technical Advisory Committee is coordinated by the Burns Paiute Tribe Natural Resources Department.
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Questions about what you can do or want to learn more?
Contact the fisheries manager at the Burns Paiute Tribe by using the contact form below. |