Nonnative brook trout exist in high numbers in the Upper Malheur. The 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 native in the Upper Malheur and led to the population being classified as having a “high risk” of extinction. Recovery Criteria for the Malheur Recovery Unit cites stable or increasing abundance trends in both local populations and the reestablishment of connectivity between the separated populations as actions necessary to achieve delisting. However, it has also been deemed necessary to achieve a reduction or elimination of threats from brook trout interaction in the Upper Malheur prior to restoration of passage. Full recovery of Malheur River bull trout is therefore contingent upon minimizing the threats posed by brook trout interaction in the basin. Brook trout are a primary limiting factor to bull trout recovery.

Reducing the effect of brook trout on bull trout is strategized under Objective 4.1 of the Subbasin Plan. The task of implementing a feasible and biologically supportable brook trout removal project received priority one designation under the plan for the Malheur Recovery Unit (Task 2.5.1). According to Task 6.1.2 for the recovery unit, BPT proposes to take the lead in implementing this effort. The draft Malheur River Bull Trout Implementation Strategies and recent draft updates to the USFWS Recovery Plan also identifies reduction of brook trout populations as a priority limiting factor necessitating immediate action.

Implementation of mechanical methodology to control brook trout in the Malheur River began through this project in FY2011.  BPT considers current use of mechanical methodology and baseline data collection as “Phase I” of suppression efforts, as approved in the FY2012 Categorical Review of Resident Fish projects.  "Phase II" will consist of a prioritized and tiered approach to velocity barrier installation and chemical treatment of the seventy plus miles of tributary habitat affected by brook trout.  “Phase II” will be contingent upon the results and baseline establishment in “Phase I” (e.g., barrier site selections, success of electrofishing/weir removal efforts, etc.), and the continued collaboration between state and federal agencies and BPT.

Project work elements in 2014 will include:
1)  operation of a weir and contiguous electrofishing removal in Lake Creek to exclude brook trout from bull trout spawning areas in reaches of high documented rates of hybridization;
2)  (conditional*) operation of a weir in Meadow Fork Big Creek to evaluate the efficacy of utilizing velocity barriers to preserve bull trout strongholds;
3)  (conditional*) snorkel surveys in Meadow Fork Big Creek to delineate the upper limits of brook trout distribution and further define proposed actions for "Phase II";
4)  limited spawning surveys and regular night checks in Meadow Fork Big Creek to ensure that the weir causes minimal impacts to use of reach by fluvial bull trout;
5)  product oriented interagency coordination to a) attract cost share to this project, b) identify critical uncertainties that will shape implementation of "Phase II", c) disseminate information to project partners and the public in order to preemptively solicit peer review and feedback, and d) move forward with statutory and regulatory processes that must be completed before "Phase II" is implemented.

These efforts coincide with additional projects funded by other sources: use of quantitative PCR (polymerase chain reaction) to detect changes in abundance of brook trout and to monitor resulting trends in bull trout (Bureau of Reclamation funding); gill net, angling, and electroshocking removal in the primary seed source area that occur above habitat occupied by bull trout and severed from upstream movement by natural barriers (Bureau of Reclamation funding); and installation of a PIT tag array at the confluence of the two tributaries currently targeted for brook trout removal (U.S. Fish and Wildlife Service funding).  BPT has also secured a U.S. Fish and Wildlife Service Tribal Wildlife Grant for FY2014 to collect baseline data on Lake Creek and High Lake to prepare for rotenone treatment.  BPT has also secured a Western Native Trout Initiative Small Grant to conduct a fishing derby in High Lake to initiate education and outreach efforts geared at involving the public in brook trout removal.

All work elements were approved in the FY2013-2017 Categorical Review by NPCC.

*"Conditional" denotes work elements that may be adaptively implemented based on data analysis conducted from January-March 2014.  At the time of submission of this contract, the BPT is still collecting data related to these work elements; therefore, we expect to adapt based on the results of the complete 2013 field season.