Nonnative brook trout exist in high numbers in the Upper Malheur. This introduced fish poses serious threats to the long term viability of bull trout because of its ability to outcompete and hybridize with the native. Resource competition and hybridization between the two species is documented in the Upper Malheur. Brook trout threats, along with other environmental and anthropogenic factors, have imperiled the bull trout in the Upper Malheur and led to the population being classified as having a “high risk” of extinction. As identified by the Malheur River Technical Advisory Committee (TAC), brook trout are the primary limiting factor to bull trout recovery. Accordingly, 2015 Bull Trout Recovery Plan criteria for the Upper Snake River Recovery Unit and Upper Malheur Core Area state that addressing the threat of brook trout is ‘an action that must be taken to prevent extinction or prevent the species [bull trout] from declining irreversibly in the foreseeable future’. Additionally, reducing the effect of brook trout on bull trout is strategized under Objective 4.1 of the NPCC Subbasin Plan. Full recovery of Malheur River bull trout is therefore contingent upon minimizing the threats posed by brook trout interactions.

BPT has taken the lead in implementing this management action.  Implementation of mechanical methodology to control brook trout in the Malheur River began through this project in FY2011. Mechanical removal methods and baseline data collection are considered “Phase I” of suppression efforts, as approved in the FY2012 Categorical Review of Resident Fish projects. BPT staff has been working on "Phase II" of the brook trout removal efforts alongside the agencies comprising the TAC. This Phase II approach is proposed to provide long-term eradication success.  “Phase II” is contingent upon the results and baseline establishment in “Phase I” (e.g., barrier site selections, conclusions from electrofishing/gill net removal efforts, etc.), and the continued collaboration between tribal, state and federal agencies in the TAC.

The TAC formalized a strategy for the eradication of brook trout called the "Upper Malheur Watershed Bull Trout Conservation Strategy" (Strategy). This document was vetted through subject matter experts at a workshop hosted by USFWS in Fall of 2016 and finalized in FY2017. The methods outlined in the Strategy are actions proposed by the Burns Paiute Tribe to be evaluated by BPA through appropriate regulatory processes. Since then, this project continued to address data gaps concerning streams included in the Strategy as well as continuation of regulatory processes under the National Environmental Policy Act (NEPA), the Wilderness Act, and Section 106 of the National Historic Preservation Act. BPT will continue mechanical removal of brook trout in key areas as a place holder to minimize effects to bull trout until a more permanent and effective solution is implemented.

In the fall of 2021 the Burns Paiute Tribe and BPA determined that the utilization of rotenone will initially occur within High Lake and Lake Creek above Lake Creek Falls to serve as a pilot action. The anticipated application is being planned to occur within the 2023 performance period. For this action to occur it has been determined that a Supplemental Analysis is to be developed by BPA and the Tribe.  BPA will be the lead for the writing and development of the document and BPT will assist in any aspects deemed necessary including, but not limited to, writing, editing, and reviewing portions of the document, data analysis and sharing, and public scoping. In addition to NEPA assistance, in FY2023, BPT will continue to gather baseline data necessary for implementation of the proposed action or alternative actions in the Strategy streams.

In 2023, these efforts will continue to rely on inter-agency collaboration to maximize effectiveness.  Through this collaboration, this project has attracted substantial in-kind contributions from partners. BPT will continue to seek out further cost-share opportunities in order to maximize the effectiveness of this project.

Work elements in the FY2023 SOW were viewed as the logical progression of this project by BPA staff and supported by NPCC following the most recent Categorical Review period in 2020. Additional elements for FY2023 include the monitoring of water temperatures and brook trout presence in other areas of the Malheur watershed, the sampling of native fish species, assisting with bull trout spawning surveys, data compilation and analysis, report writing, and continuing to collaborate with government agencies, non-profits, watershed councils, and the public to improve fisheries resources in the Burns Paiute Tribe’s ancestral territories.