To: W. Bill Booth, Council Chair
From: Eric Loudenslager, ISRP Chair
Background At the Council’s June 10, 2009 request, the ISRP reviewed a response received from the Confederated Tribes of the Warm Springs Reservation regarding our December 15, 2008 review of the Columbia River Fish Accord proposal titled Deschutes River Fall Chinook Research and Monitoring (200830600). In our December 2008 review, we found that the proposal did not provide sufficient information for our technical review and thus did not meet scientific review criteria.
The project intent is to access multiple methods and develop new methods, if necessary, in order to accurately estimate Deschutes River Fall Chinook escapement. Weather and turbidity during fall Chinook upstream migration and spawning has made accurate estimates difficult. The project proponent also intends to assess the feasibility of developing a full duplex PIT tag array to span the width of the Deschutes River near the mouth, which would allow escapement assessments using a non-visual method.
Recommendation: Meets Scientific Review Criteria In Part (Qualified)
- Objective 1 – Meets Scientific Review Criteria (in part)
The need of determining spawners’ genetic composition was adequately justified, but our concern with the inability to distinguish between wild-origin and hatchery-origin fish was not addressed. An accurate count of wild Chinook escapement is not possible if this distinction cannot be made. This ability, both in terms of accuracy and efficiency, remains a critical uncertainty for the project to succeed. The tasks to complete this objective should begin with feasibility investigations that demonstrate that hatchery and wild fish can be accurately distinguished with the proposed genetic baseline. Full implementation should follow reporting and review of the feasibility data.
Baker et al. (2009) [reference cited by proponents in their response to the ISRP’s review] state: "a study to determine stock origin of Chinook carcasses collected aster successfully spawning is currently underway (J. Graham, CTWSRO, pers. Comm.)." The proponents need to clarify that the proposed objective does not duplicate ongoing research already funded by other sources.
- Objective 2 – Meets Scientific Review Criteria
- Objective 3 – Does Not Meet Scientific Review Criteria
Objective 3 is premature because the feasibility of the PIT tag array is unknown and including a project objective that relies upon a successful deployment of a PIT tag array is not appropriate at this time.
- Objective 4 – Meets Scientific Review Criteria (Qualified)
In the last review of this proposal (re Task 4.3 of Objective 4), the ISRP asked how new redds would be distinguished from those observed/recorded on previous surveys. The proponents provided no information to address this question. We would expect that this minor point be addressed in the next draft of this proposal.
- Objective 5 – Meets Scientific Review Criteria
Specific CommentsProject title and objectives consistencyThe authors adequately addressed the ISRP’s concerns with the original title of this proposal which indicated that the goal of the project was to establish biologically based escapement goals by changing the title to "Deschutes River Fall Chinook Research and Monitoring." The goal of this project is to improve monitoring of fall Chinook salmon populations in the Deschutes River. It will not establish biologically-based escapement goals.
Objective 1 – Genetic AnalysisThe ISRP’s recommendation regarding the need for the genetic analysis to differentiate Deschutes River fish from strays was adequately addressed. Clearly, the preliminary data indicate that the number of non-Deschutes River fish at the site where returning adult fish are enumerated is quite high. However, our request for more information about the ability to differentiate wild and hatchery-origin Deschutes River salmon was not addressed. This ability, both in terms of accuracy and efficiency, remains a critical uncertainty for the project to succeed.
Objective 2 – PIT Tag Array FeasibilityIn response to the ISRP’s questions regarding the lack of details in justification for the full duplex PIT tag array, the proponents provided adequate information regarding the challenges associated with the establishment of a PIT tag array on the Deschutes River and a detailed list of steps planned to determine the feasibility of installing such an array.
Objective 3 – Developing Escapement Methods The response to the ISRP’s concern that this objective relies on the installation of a PIT tag array indicates that there is a high degree of confidence that a PIT tag array will be installed during the 10-year lifespan of this study. This optimism appears to be based on the fact that a PIT tag array was installed on the John Day River. However, in the response to our comments on Objective 2, the authors indicate that, despite the success on the John Day River, there are daunting challenges that must be addressed in order to install the PIT tag array on the Deschutes River. For this reason, the request for funding to implement Objective 3 is premature at this time. However, if there were an alternative to a full-river PIT tag array that could be implemented that would enable this objective to be addressed, inclusion of this objective in the current proposal would be reasonable.
Objective 4 – Validation of Aerial Redd Counts
The comments the ISRP provided on the original proposal included a question about the redd census procedure described in Task 4.3 (of Objective 4). We asked for some clarification on the determination of redd superimposition and how new redds will be distinguished from those observed on previous surveys. No response to these comments was provided. These concerns are not major issues, and the approach proposed for completing Objective 4 is appropriate. However, results will be much improved if the project proponents develop a methodology that addresses these concerns.
Objective 5 – Carcass Surveys The proponents provided a detailed adequate response regarding the ISRP’s questions about the tagging of wild fall Chinook juveniles including a good summary table of tag data.
