The Council, in cooperation with the U.S. Fish and Wildlife Service (USFWS), asked the Independent Scientific Review Panel (ISRP) to review the Steelhead Hatchery Programs of the Lower Snake River Compensation Plan (LSRCP). The LSRCP is a federal program designed to mitigate the impacts of construction and operation of the four lower Snake River federal dams (Ice Harbor, Lower Monumental, Little Goose, and Lower Granite) on Chinook salmon and steelhead populations in the Snake River Basin. The LSRCP goal for steelhead is to return 55,100 adults to and through the LSRCP project area to compensate for the estimated annual loss of 48% of the return relative to the base period of the late 1940s and early 1950s. To pursue this goal, the LSRCP program rears steelhead at five separate hatchery production facilities and operates numerous adult collection and smolt acclimation facilities in Washington, Oregon, and Idaho. These facilities are spread throughout all the major subbasins in the lower Snake River, including the Tucannon, Clearwater, Grande Ronde, Imnaha, and Salmon and also in the Walla Walla subbasin in the mid-Columbia River. The USFWS owns the hatchery facilities and administers the LSRCP program through a direct funding agreement with the Bonneville Power Administration (BPA). State, federal, and tribal fish and wildlife agencies in the region operate the LSRCP facilities.
In general, the ISRP finds that the LSRCP is a highly effective program that has practiced good science, has implemented sound actions, and has adapted to changing conditions and new findings. The steelhead program has achieved impressive success in restoring and maintaining sport fisheries throughout the Snake River Basin, even in years when hatchery and natural adult returns are low for reasons beyond the program’s control.
The LSRCP faces major challenges to mitigate the impacts of construction and operation of the four lower Snake River dams on salmon and steelhead populations in the Snake River Basin. Salmon and steelhead must migrate long distances from their natal streams to the ocean and adults that return must pass through six to eight hydropower dams and reservoirs to reach the spawning grounds or location of release in the Snake River subbasins. In addition, climate change and habitat degradation over the last 50 years have reduced freshwater and ocean productivity and caused major declines in salmon and steelhead populations throughout the Pacific Northwest. Returns of adult steelhead produced by the LSRCP to the project area declined 10-fold in recent years, from more than 140,003 steelhead in the 2009-10 run year to only 13,027 in the 2019-20 run year.
The LSRCP monitors and evaluates in-hatchery performance, annual adult returns, smolt-to-adult return (SAR), smolt-to-adult survival (SAS), straying, harvest, catch-escapement distributions, and ecological interactions with natural populations. Overall, during the past 14 run years (2009-10 to 2022-23), the LSRCP steelhead hatchery programs slightly exceeded their goals for adult returns on average, although the high average is driven in part by very high returns for three run years from 2009-10 to 2011-12. Moreover, the results varied greatly within and between programs. Overall, six of twelve programs achieved their goal.
One of the many strengths of the LSRCP Program is the high level of in-hatchery performance. Specifically, pre-spawning mortality of broodstock is low and green egg-to-smolt survival is excellent, exceeding the 65% percent goal on average in all hatcheries. In general, most hatchery programs met their smolt production goals for 85% of the brood years. The excellent in-hatchery performance has little scope for improvement and indicates that alternatives for the LSRCP to address overall survival challenges through hatchery management changes are generally limited to improving rearing and release strategies to enhance smolt quality and smolt-to-adult survival. The mean SAR and percent of SAR goal achieved of individual programs varied greatly. The percent of goal achieved ranged from less than one-half to over two-times the target.
Straying of LSRCP adults into ESA-listed natural populations within Mid-Columbia River Steelhead Distinct Population Segment (DPS) was identified as a significant problem in the past but declined significantly beginning with the 2012-13 return year. From the late 1980s through 2006, high proportions of outmigrating Snake River steelhead smolts were barged to the lower Columbia River. After barging was greatly reduced, stray rates into and the proportion of strays spawning in natural populations (pHOS) in the Deschutes and John Day rivers have been negligible and within acceptable risk.
Contributions to mainstem Columbia River recreational and tribal fisheries below the project area were lower in the most recent years than in the past due to low returns and harvest management changes. The LSRCP provided recreational harvest opportunities in Washington, Oregon, and Idaho in the project area every year, although the number of fish harvested and the fishing effort was substantially lower than during the period prior to the last review in 2013.
Multiple factors have limited the achievement of the LSRCP goals and management objectives during the past decade including:
The SARs for the most recent years have been very low because of high mortality rates at multiple life stages in the life cycle following release of smolts. The low abundance of natural- and hatchery-origin steelhead adult returns in recent years has prevented achieving broodstock and smolt production objectives for some programs, especially the integrated broodstocks. There is limited hatchery rearing capacity and water availability to reduce rearing densities to improve smolt quality while maintaining current production goals. Monitoring is inadequate for the four supplementation programs that use integrated brood stocks, so the natural populations abundance and productivity responses to supplementation is unclear. The overshoot of Tucannon River and Touchet River adults to areas above Lower Granite Dam reduces returns to those rivers, and the strays pose significant risk to natural populations in other Snake River Basin tributaries. The limited opportunity for harvest in traditional tribal fishing areas has affected the ability of tribes to fish in those areas with traditional methods. Some areas designated for tribal harvest pose difficulties for tribal members to access. Climate change will likely continue to influence smolt-to-adult survival, hatchery operations, and performance by reducing water supplies and creating frequent and severe flow variation and severe floods, influencing adult collection and acclimation facility operations. Funding availability hampers many aspects of hatchery operations, hatchery maintenance, infrastructure improvements, monitoring and evaluation, and adaptive management actions. Decreasing water supplies at core smolt production facilities like Irrigon Hatchery, Magic Valley Fish Hatchery (MVFH), and Hagerman National Fish Hatchery (HNFH) and deteriorating hatchery infrastructure at many facilities will continue to limit production capacity, rearing density indices, increase disease challenges, and influence the success of individual programs. The LSRCP Program has demonstrated adaptability and capacity to address factors such as those listed above and to implement adaptive changes. The LSRCP’s most prevalent management changes for steelhead have been to decrease smolt production to address water availability and hatchery infrastructure limitations, change brood stock sources, and alter release locations. This production effort is coupled with extensive monitoring, evaluation, and research to provide information for adaptive management decision processes and to improve program performance. The LSRCP is forward thinking in initiating major deferred maintenance projects, identifying critical hatchery infrastructure improvement needs, and conducting some climate change impact assessments.
In this document, the ISRP identifies thirteen key findings and programmatic issues that affect program performance and make the following summary recommendations for future actions by the LSRCP Program:
Continue to monitor sport and tribal fisheries in the project area to estimate key performance metrics and characterize success. Continue to monitor straying by LSRCP steelhead adults into Mid-Columbia River natural populations to determine if the recent reduced levels are sustained in the future. Use a structured decision process to evaluate the benefits and risks of the proposed future alternatives for both the Tucannon and Touchet river programs. Under current conditions, there appears to be a limited set of actions that can be taken to address performance, overshoot, and straying. Exceptions include exploring the politically complex option of restoring reservoirs back to free-flowing reaches or providing adequate downriver passage in the lower Snake River for adult steelhead that overshoot and seek to return to their home river. Develop and implement sound study designs to assess the benefits and risks of supplementation programs in the Touchet, Tucannon, Imnaha, and East Fork Salmon rivers. Complete climate change assessments for the hatcheries that are at most risk. Develop and implement a systematic decision process to prioritize infrastructure improvements. Investment of $200M for infrastructure improvements is critical to the future success of the program. It is essential that the most important and beneficial projects are implemented, especially because $400M in projects have already been proposed. Develop approaches and conversion factors to maintain continuity and comparability of SAR and SAS data generated with new Parentage Based Tagging (PBT) and PIT tag methods with past data generated using Coded Wire Tag (CWT) methods. Clearly articulate the basis and justification for adjusting SAR and SAS targets when smolt production levels are changed. The LSRCP and cooperators should develop a shared database for all data including Parental Based Tagging (PBT), develop systematic data quality assurance and analytical processes to maintain up-to-date estimates of key performance metrics, and work with the Coordinated Assessments Partnership (CAP) to complete entry of data and metadata into the Coordinated Assessments Data Exchange (CAX) database for key hatchery performance indicators. As stated in the 2022-2023 Spring/Summer Chinook Review, the ISRP appreciates the USFWS and the LSRCP partners’ constructive and cooperative approach to evaluation, review, and coordination, and the ISRP hopes its recommendations can help the program address its many daunting challenges and move the program closer to meeting its goals consistently. That stated, the ISRP understands that many of the challenges that limit success, especially post-release survival, cannot be fully addressed by LSRCP Program actions alone. The lack of consistent achievement of objectives in recent years is often despite, not because of, the extensive efforts of the program implementers.
