In response to the Council’s June 20, 2019 request, the Independent Scientific Review Panel (ISRP) reviewed the Addendum to the 2008 Revised Master Plan for the Hood River Production Program (HRPP) produced by the Confederated Tribes of Warm Springs (CTWS) and Oregon Department of Fisheries and Wildlife (ODFW). The HRPP consists of improvements to supplementation, research, monitoring, evaluation, and habitat.
The addendum and supporting material were submitted to meet the Council’s request to provide additional information based on the ISRP's Step Review of the 2008 Revised Master Plan (ISRP 2008-10). The ISRP found the 2008 Revised Master Plan Meets Scientific Review Criteria - In Part (Qualified) and recommended that the co-managers revise and update the Master Plan based on the qualifications and comments in the review. The ISRP’s 2008 review stated that the revised master plan was “an impressive step forward in concept, decision-logic, organization, and scientific justification.” However, the ISRP recommended “Qualified” because of concerns about “1) using acclimation ponds to volitionally release steelhead in the mid/upper watershed where released fish can residualize; 2) using hatchery-origin adults for broodstock when natural fish are low in abundance, and; 3) insufficient justification for assessment methods for the monitoring component.” The ISRP recommended “In Part” because, although the facility improvements for the proposed spring Chinook rearing experiment were justified, the construction of six production ponds at Moving Falls could not be scientifically justified until the experiment was complete; the six ponds were not needed for the experiment but were proposed for program implementation.
On October 15, 2008, the Council approved the Revised Master Plan, recommended that the Phase 1 activities associated with the comparative release evaluation and fish trapping facilities proceed, and called on the proponents to develop additional information to address the issues raised by the ISRP, including updating the Master Plan for final review in 2013 (Council decision letter and decision memo).
For the past 11 years, the HRPP has proceeded with Phase 1 activities. The Addendum focuses on key program changes since the approval of the Revised 2008 Master Plan, and on how the Council’s and ISRP’s issues from 2008 have been addressed. For this review, the CTWS and ODFW are requesting to increase spring Chinook production from 150,000 to 250,000 yearling smolts, but no changes are being proposed to the winter steelhead hatchery program.
The ISRP recommends that the HRPP’s 2019 Step submittal “Meets Scientific Review Criteria (Qualified).”
The ISRP finds that the Addendum to the Hood River Production Master Plan is well written and adequately addresses many of the qualifications from the 2008 ISRP review. It includes revised objectives for both the winter steelhead and spring Chinook integrated hatchery programs, All-H Analyzer (AHA) model simulations to justify proposed levels of release and harvest, and a broodstock management plan for winter steelhead. The proponents are making good progress in developing alternative approaches to enumerate smolts and adults following the removal of the Powerdale Dam and its associated infrastructure. They are addressing genetic and ecological risks associated with precocious maturation and residualization of hatchery fish. The ISRP commends them for their prudent application of the HSRG guidelines and their thorough responses to the ISRP’s questions.
The ISRP recommends that the following qualifications should be addressed in the next iteration of the Step Review. The ISRP also provides some specific comments, queries, and editorial suggestions to be considered as the program proceeds.
Winter steelhead program
1. Justify the goals and quantitative metrics for the winter steelhead program. The long-term viability of this primary population of the ESA-listed Lower Columbia River Steelhead could be undermined by indefinitely continuing hatchery supplementation to achieve an unrealistic target. Hatchery supplementation to provide opportunities for selective in-basin harvest can also promote the recovery of the natural population only so long as the natural population is being boosted to levels that are self-sustaining without supplementation. The ISRP is concerned that the escapement target of 1,100 natural origin winter steelhead is too high given existing habitat capacity in the Hood River. The recent 5-year average escapement of 1,041 natural spawners included 43.7% hatchery origin fish that had escaped the fishery and traps. Continuing hatchery supplementation above the existing self-sustaining level is likely to reduce long-term fitness in the natural environment, unless habitat restoration efforts succeed in creating conditions that will support a larger self-sustaining population in the future. Accordingly, the proponents need to:
- Revise (or justify) the escapement target of 1,100 natural origin winter steelhead by providing statistical analyses or statistical models based on all available data related to current productivity and carrying capacity (i.e., density dependence). The AHA analysis presented in Table 13 suggests that the self-sustaining population under current conditions is < 400 natural origin spawners.
- Monitor the abundance of natural origin smolts and total smolts to estimate freshwater productivity (i.e., smolts-per-natural spawner). Is it feasible to restart the smolt enumeration program that was terminated after 2014? If the program was terminated because of uncertainty distinguishing summer and winter steelhead smolts, consider contacting the CRITFC Hagerman Lab about the feasibility of using genetic analysis (see qualification 6).
- Estimate the maximum self-sustaining population under planned future conditions based on evidence of successful habitat restoration efforts in the Hood River subbasin.
- Describe how habitat restoration efforts in the Hood River subbasin are being evaluated and indicate if reference streams are being used. Evaluation of fish responses to habitat restoration actions typically requires reference streams for use in Multiple Before After Control Impact (MBACI) designs (when habitat improvements are large and sudden) or Stair Case Designs (when habitat improvements are added incrementally over time).
- Revise the AHA modeling tables as appropriate if values change as a result of new analyses of capacity and productivity, including the winter steelhead escapement target.
2. Provide quantitative decision rules that specify the conditions and time frames that would trigger changes to hatchery supplementation of winter steelhead (including reduction or termination). Examples might be a continuing decline in natural origin returns that reduces pNOB to below a specified threshold or a continuing increase in natural spawners (both HOS and NOS) to densities that cannot be sustained by existing habitat.
3. Improve monitoring and evaluation methods to meet NOAA criteria for the precision of escapement estimates (i.e., CV < 15%) for natural and hatchery origin winter steelhead.
4. Provide estimates of all hatchery steelhead removed each year including those harvested by anglers and those removed in all traps, ladders, and weirs in the subbasin. This information is critical to documenting program success and evaluating the overall harvest goals. Describe how the harvest of winter steelhead will be monitored in the future given the lack of funding to support the harvest survey in 2019. Will the East Fork Irrigation District ladder and adult trap be operated every year as a means to remove hatchery fish (in addition to obtaining hatchery broodstock)?
5. Reconsider the decision not to release some hatchery steelhead smolts in the lower river. Releasing a portion of the smolts in the lower river would make it easier to achieve the harvest goal (i.e., average annual harvest of 876 adults), which requires selectively catching 67% of hatchery origin fish in the terminal fishery. Describe what steps will be taken to increase the terminal harvest rate by improving angler access and how these actions will be evaluated.
6. Examine the feasibility of conducting genetic analyses of tissue samples from smolts collected in the rotary screw traps (RST) to:
- distinguish summer and winter steelhead smolts to determine their relative abundance (see qualification 1b); and
- monitor the extent of hybridization between residual steelhead and cutthroat trout (see Christie et al. 2011).
Spring Chinook program:
7. Develop a quantitative objective for harvests associated with the proposed increase in hatchery production of spring Chinook salmon, and provide background information and decision criteria to justify the increase.
8. Evaluate options and propose a plan to estimate the annual smolt production and parental spawning abundance of natural origin spring Chinook in the Hood River subbasin. To date, natural origin spawning abundance has been estimated in only one year (2016). A primary objective should be to analyze density effects on productivity (e.g., the decline in smolts-per-spawner with increasing spawning abundance) to develop more explicit goals for terminal harvests and escapements. We urge the proponents to determine the relationship between river conditions (e.g., discharge and water height) and trapping efficiency for each RST, and to use that relationship to refine estimates of smolt production from trap catch data.
9. Develop a plan to monitor hatchery origin Chinook returns and to reduce pHOS when total spawner abundance approaches the capacity of the watershed to support both natural origin and hatchery origin Chinook.
10. Compare straying rates of adult spring Chinook with different rearing histories. Some fish are incubated, reared, and released entirely within the Hood River subbasin, whereas others are incubated and reared in the Deschutes River subbasin prior to being acclimated and released back into the Hood River subbasin. The ISRP is concerned that in years of low harvest rate, straying of Hood River hatchery origin Chinook may adversely affect other natural populations in neighboring watersheds.
11. Review existing studies and/or conduct new research to evaluate the risk that the productivity of natural origin winter steelhead or other non-target native fishes might be adversely affected by increasing hatchery releases of spring Chinook smolts from 150,000 to 250,000 annually. Previous work in the Yakima River by McMichael and Pearsons (1998), Temple and Pearsons (2012), and Fast et al. (2015) suggests that hatchery supplementation of spring Chinook generally had no detectable effects on resident rainbow trout and other native fish species. However, Pearsons and Temple (2010) did find reductions in rainbow trout abundance and biomass in one Yakima River tributary that might have been linked to the continuing annual release of hatchery spring Chinook juveniles. Consequently, we suggest that the proponents consider assessing possible impacts of continuing annual releases of hatchery origin spring Chinook on the abundance and growth of Hood River steelhead.