On May 24, 2023, the Council asked the ISRP to review a response from Confederated Tribes of the Warm Springs Reservation of Oregon (CTWSRO), regarding Project #2007-157-00, Bull Trout Status and Abundance on Warm Springs Reservation. The project is designed to continue long-term status and trends monitoring of bull trout to evaluate the efficacy of potential management treatments, conduct monitoring to determine distribution of bull trout and brook trout on the Warm Springs Reservation, and support bull trout populations by suppressing brook trout populations. The response was submitted to address the ISRP’s request for a response on several issues regarding the proponent’s proposal associated with the Resident Fish and Sturgeon Project Review2019/2020. As part of the Council’s recommendation in 2020, the proponents were granted a time extension to address the ISRP’s preliminary recommendation for a response.
In the ISRP’s 2020 preliminary review, the ISRP found that more information was needed to evaluate the proposed work and asked for a response on the following topics:
- A summary of insights and conclusions from prior work
- Goals and SMART objectives for new and ongoing work, and research hypotheses
- Methods descriptions that align directly with goals and SMART objectives
- A structured adaptive management framework
- A description of the monitoring, analyses, and data sharing that will be conducted to accomplish the new objective "to advance the understanding in bull trout ecology in the lower Deschutes Subbasin."
The ISRP’s 2020 request for a response regarding item three on methods included questions regarding a proposed action for bull trout translocation/supplementation in Mill Creek. The proponents indicated that they dropped the proposed translocation-supplementation action after the last review because the Lionshead Fire in 2020 severely degraded prospective bull trout habitat in the Mill Creek watershed. However, those ISRP 2020 response request items may apply in the future because the proponent’s response indicates that habitat assessments will be conducted to determine the suitability of Mill Creek for bull trout translocation.
Final recommendation: After reviewing the response, proposal, and supporting material, the ISRP recommends that the project “Meets scientific review criteria (conditional).”
The ISRP recognizes the challenges that Covid and staffing levels have created and greatly appreciates the time and effort required to prepare the response, helping the ISRP understand the proposal and addressing some of the ISRP’s questions. However, several concerns and issues were not addressed adequately, and some were not addressed at all because of confusion about the ISRP’s request. Several conditions need to be met before this proposal can be considered as fully meeting scientific criteria. The ISRP recommends the following conditions be addressed by the proponents in the form of a response letter to the ISRP before the next contract period or before initiating field sampling and the proposed brook trout removal effort.
Condition 1. Adaptive management process: Further information is needed to fully understand how the project evaluates its past actions, assesses monitoring data, and modifies project methods and actions when needed.
Condition 2. eDNA methods, analysis, and occupancy modeling: eDNA sampling is a new method that the proponents will use to develop an updated inventory of known bull trout/brook trout ranges by the year 2025. Because of the methods’ central role in determining bull trout and brook trout distributions and the project’s limited experience with the methods, the ISRP recommends that the proponents describe the design of the data collection, analysis, modeling, and interpretation in the response letter to the ISRP.
Condition 3. Brook trout reduction: The proponents need to explain the scientific basis for the 15% reduction value for brook trout suppression and provide supporting information and documents. If off-reservation areas serve as a source of brook trout, will suppression be conducted off-reservation to achieve objectives?
Condition 4. PIT tagging: The proponents should explain why they are PIT tagging bull trout and how their analysis of PIT-tagged bull trout will address their hypotheses about bull trout population responses.
Additional Condition, not needing a response to the ISRP:
Condition 5. Goals and objectives: The ISRP appreciates that the proponents revised the goals and objectives section in their response document, and several of the objectives and associated hypotheses are improved, but the ISRP recommends that the goals and objectives be strengthened in the next annual report and workplan.
Final Comment: The ISRP appreciates the proponents’ responses to our questions, which address many of the ISRP's concerns. Given the new approaches being used by the CTWSRO and the complexity of the implementation and analyses, the proponents’ efforts to address these conditions and recommendations will strengthen the actions to protect and enhance bull trout populations on the Warm Springs Reservation.