The sponsors should be congratulated for preparing a very strong proposal. The proposed work would benefit bull trout recovery and provide useful background information on the status of redband trout in the Malheur basin. Success of the Lake Creek brook trout suppression effort hinges on significant reduction in brook trout abundance in High Lake.

1. Purpose: Significance to Regional Programs, Technical Background, and Objectives

The goals of the proposed work are to suppress brook trout in priority streams supporting bull trout within the Malheur basin and to conduct a basinwide assessment of redband rainbow trout abundance. Mechanical methods, such as electrofishing and strategically placing weirs to impede brook trout movement into bull trout spawning areas will be used to suppress brook trout. Mechanical methods are being tried as an alternative to a piscicide. The sponsors also propose to undertake a statistically rigorous estimation of abundance of redband trout throughout the Malheur basin.

The sponsors present a convincing argument, based on previous studies in the Malheur basin, that suppression of non-native brook trout, which threaten listed bull trout through genetic introgression and competition, is necessary for bull trout recovery in the basin. Furthermore, the work on redband trout seems justified as this fish is listed as a “species of concern” by several state and federal agencies, and little is known about their distribution and abundance in the Malheur basin.

Especially for the Lake Creek site, the technical background is provided in an unusually strong and complete manner that incorporates quality maps, graphics, and photos to very clearly explain the situation and focus on the nature of the problem. Much of it is based on previous work in the basin that provided needed information on distribution, abundance, movement, and genetic structure of brook and bull trout, and to some extent, redband trout. Furthermore, work done on bull trout and brook trout outside the project area are nicely referenced and used to help design the proposed work. The proposal is well prepared, easily read, and well- grounded scientifically.

The proposal provides a good discussion of how the sponsors’ efforts, and jurisdiction, coordinate with co-managers, and regional and federal agencies and programs. There are indications of unusually strong efforts to communicate. This project is closely tied to other projects in the Malheur basin and to several regional plans. The project directly responds to the Columbia Basin Fish and Wildlife Program 2009 Amendments, the USFWS Bull Trout Recovery Plan, the Malheur River Subbasin Implementation Strategies for bull trout (2011 draft), and the Malheur Subbasin Management Plan. The sponsors have been awarded several non-BPA contracts for other related components of the proposed work.

There are seven objectives, several of which commit to gathering statistically sound estimates of the status of populations of native species. All objectives appear sound and important. They address the crucial problems identified by the sponsors. Accomplishment of these objectives should aid in recovery of bull trout in the basin and provide useful background information on redband trout.

Critical to the success of the Lake Creek project is successful suppression of brook trout in High Lake, a headwater lake that serves as a source population of brook trout for Lake Creek. Removal of brook trout from High Lake has been ongoing for a couple of years. Based on the information presented in the proposal, it appears that a large proportion of the brook trout population has already been removed. Because the lake is relatively small (~ six acres) there is a high probability that the project will be able to significantly reduce brook trout abundance.

2. History: Accomplishments, Results, and Adaptive Management (ISRP Review of Results)

Accomplishments to this point are considerable. The sponsors present a thorough discussion of results that not only describe previous baseline work but also serve as a justification for the currently proposed work. The proposal clearly describes the work completed to date on bull trout, which is largely radio tracking, and how it is useful in developing the design of the proposed suppression efforts. The limited work to date on monitoring the status of redband trout in the Malheur basin was adequately described. Plans for developing a stronger database were outlined.

Discussion of results would have been improved if the sponsors provided some analysis of habitat quality and quantity including not only temperature but also other habitat factors such as deep pools, and large wood, and whether habitat is a limiting factor for bull trout. A question for the sponsors to consider is: would habitat enhancement as well as direct mechanical suppression of brook trout in concert improve chances of bull trout recovery?

In some cases, bull trout and brook trout abundance from earlier surveys is expressed as total numbers of fish. In future work, the sponsors should consider expressing abundance as densities or CPUE, for example in the High Lake brook trout removal project. These expressions of abundance would make comparison between locations more relevant as different sampling locations may differ in sampling effort and amount of habitat sampled. 

Adaptive management is clearly evident in this work. Considerable previous work in the basin has focused on gaining baseline information on population status of brook, bull, and redband trout, and factors limiting native trout abundance and distribution. Based on this work the sponsors propose to begin more management oriented work on brook trout removal and restriction of their movement into streams where they are absent or at low abundance, the response to bull trout to the brook trout suppression efforts, and a more systematic and complete assessment of redband abundance and distribution.

ISRP Retrospective Evaluation of Results 

This project is well designed, with important accomplishments to date. The project has progressed significantly over the years. The sponsors present a thorough discussion of results that not only describe previous baseline work but also serve as a justification for the currently proposed work. The baseline work consisted of obtaining needed information on status and trends of bull trout and, to some extent, redband trout in the Upper and Middle Malheur basin, and identifying limiting factors for bull trout. Brook trout were identified as a major limiting factor. The sponsors propose to undertake brook trout suppression in key bull trout streams to address this problem. The progression from initial assessment of status and trends to the direct management action of brook trout suppression is both logical and necessary for bull trout recovery and is an excellent example of adaptive management. 

Critical to the success of the project is successful suppression of brook trout in a headwater lake that has served as a source population of brook trout. The ISRP recommends that the sponsors seriously consider treatment of the lake with a piscicide as the methods they are currently using probably will not lead to complete eradication of brook trout.

The sponsors also plan to undertake a systematic and complete assessment of redband trout abundance and distribution in the Malheur basin. This work is well planned and well designed and should provide much needed information on redband status and trends. The ISRP recommends that the sponsors evaluate limiting factors as part of this assessment.

3. Project Relationships, Emerging Limiting Factors, and Tailored Questions for Type of Work (hatchery, RME, tagging)

Relationships among agencies and the Tribe seem well developed and clearly described. Recovery of bull trout in the Malheur basin is a multi-agency effort in which the Burns Paiute Tribe has taken the lead role. The proposal directly and comprehensively addresses the non-native fish problem but does not deal with effects of climate change, which could elevate stream temperatures directly jeopardizing bull trout and possibly benefiting brook trout.

4. Deliverables, Work Elements, Metrics, and Methods

Most deliverables contribute directly to accomplishment of the objectives. The methods for the most part appear sound. The work is well designed. We commend the sponsors for using a GRST design for sampling redband trout (Deliverable 3) and estimating abundance of brook trout (Deliverable 7) and bull trout (Deliverable 9) in Lake Creek.

The proposed work has been nicely thought through and is very clearly laid out. The detail and explicit emphasis in this section of the proposal indicates that project personnel are doing nearly all that is currently possible to achieve the rapid and concerted brook trout suppression required to bolster Lake Creek bull trout.

Reviewers, however, continue to support chemical suppression of brook trout in High Lake. Mechanical suppression, especially if it includes capture of all spawning adult brook trout in the outlet and inlet, might be able to significantly reduce abundance. However, with this species' ability to successfully spawn in spring seeps in the lake proper, it is unlikely that eradication would be possible. Night electrofishing in a raft with a throwable electrode has proven effective in ponds as fish may move into shallows at night and freeze in the craft's underwater lights.

There are other reasons for support of chemical treatment of High Lake. It was historically fishless and fits with recent USFS emphasis on restoring lakes to a fishless state to favor amphibians and other native species. There is a precedent to using chemical treatment in Wilderness Areas. Montana Fish, Wildlife and Parks (pers. Com. Matt Boyer, MFWP, Libby/Kalispell) recently has done so.

Weir placement and operation on Meadow Fork Big Creek should be suitable for restricting movement of brook trout into the stream. This activity appears to be a valuable component of the project.

The proposed survey protocol (Deliverable 3), designed to develop a robust assessment of redband by electrofishing non-privately-owned sections, seems adequate. The links to location maps were helpful. Some habitat attributes will also be recorded.

Reviewers suggest that the survey also could and should be used to gain understanding of factors limiting redband abundance with only minor additions to protocol, but it can only be successful if thought through prior to initiation of fieldwork, rather than after-the-fact. A very few simple hypotheses should be framed, such as "large redband are only present if pool depth or volume exceeds some particular dimension." The process does not necessarily need to be statistically rigorous, but over time might lead to the framing and testing of more elegant hypotheses.

The sponsors should consider monitoring the North Fork Malheur while the assessment of brook trout suppression and bull trout recovery in Lake Creek is ongoing. Since the North Fork is brook trout free it seems as though it could provide a useful reference site for comparison with Lake Creek. It is unclear why bull trout in Meadow Fork Big Creek will be assessed by snorkeling and not electrofishing, as will be done in Lake Creek. Meadow Creek, like the North Fork, could provide another worthwhile reference location.

The sponsors propose several metrics for evaluating success of the various suppression and control measures for brook trout including ratios of brook trout to bull trout, abundance estimates, and redd counts. It would have been useful if the sponsors summarized the quantitative target values, ranges, or clear trends of each metric that will be used to determine the success of their efforts for both Lake Creek and Big Creek. Ratios alone may not be sufficient to assess success of brook trout suppression if bull trout abundance declines at the same time as brook trout abundance; that is, a given ratio could be achieved but at the same time bull trout abundance could have declined to unacceptable levels. Additionally, it is unclear how the ratios were derived.