At the Council’s request on April 26, 2021, the ISRP reviewed a response and revised proposal from the Kootenai Tribe of Idaho (KTOI or proponents), regarding Project #1994-049-00, Kootenai River Ecosystem Restoration. The intent of the submittal is to address a condition placed on the project, by the Council, as part of the Resident Fish and Sturgeon Project Review in October 2020: “Manager address ISRP review conditions in a detailed report for the project. Report due no later than March 1, 2021.” The submittal date was rescheduled to allow for a response discussion with the ISRP and KTOI on April 17, 2021, which aided our understanding of the project and the proponents’ approach to addressing our conditions.
The ISRP’s review (2020-8) raised the following conditions:
- Condition 1. Kootenai River fertilization
- Condition 2. Lake Kootenay fertilization
- Interpretation of zooplankton trend - alternate ecological pathways.
- Predator control program for Gerrard trout and bull trout
- Potential for fertilization to contribute to the unstable kokanee-predator dynamic in Kootenay Lake
- Condition 3. Revised objectives
- Condition 4. Proposed new fertilization facility
- Condition 5. Cyanobacteria
- Condition 6. Synthesis article
The proponents submitted a point-by-point response to the ISRP’s six conditions, Kootenai/ay Nutrient Mitigation Program, Project 1994-049-00, Response to NPCC/ISRP Conditions, and a Revised proposal incorporating the responses.
The ISRP finds that the response and revised proposal adequately address the six conditions and recommends that the project Meets Scientific Review Conditions. The ISRP commends the proponents for presenting thorough responses to previous questions and concerns about the original proposal and its connections to related projects in the restoration program. This is truly an impressive program that is setting a standard to which other restoration/mitigation programs should aspire. Overall, the program is making steady progress toward the long-term restoration and mitigation goals, and they are learning much about approaches that are successful as well as those where the human-modified ecosystem responds in unexpected ways. Some basic uncertainties remain, and thus an ongoing investigation of ecosystem responses is essential for guiding this project and the practice of fertilization more broadly.
Regarding Lake Kootenay fertilization and predator control actions, the ISRP further recommends that the proponents should continue to investigate the fertilization responses and the effects of trout and char suppression of the South Arm of Kootenay Lake for the next few years. This should also include a more comprehensive investigation of zooplankton community dynamics. The purpose of the continued investigation would be to see if recovery of the kokanee population is realized and/or to verify the hypothesis that kokanee are declining in spite of increased food abundance because they are competing with younger age classes of Gerrard rainbow trout, bull trout, and Mysis. The ISRP recommends that the fertilization activities be re-evaluated in 2025 to learn if and why kokanee are recovering. A note of caution: While the proponents adequately document safeguards in place to protect bull trout and Gerrard rainbow trout, the ISRP has strong misgivings – based on an extensive literature documenting ill-conceived management actions – about targeting native species of concern to improve populations of another species, one that may simply have more economic importance. Food webs are complicated, and the proposed management actions may have unintended consequences, ones that may not be reversible.
