Beginning in 2000, the proponents (CTUIR) began an effort to reintroduce spring Chinook salmon into the Walla Walla subbasin. Initially, adult spring Chinook were outplanted into the South Fork Walla Walla and into Mill Creek. Starting in 2005, adult releases were supplemented by annual releases of 250,000 yearling spring Chinook smolts into the subbasin. Spring Chinook adult migrants were produced from the program and some natural reproduction occurred. Yet the adult returns produced from these two actions were not sufficient to reach tribal harvest and reintroduction objectives. Additionally, the continued use of out-of-basin fish was recognized as being inconsistent with best hatchery practices. The creation of a spring Chinook salmon hatchery located on the South Fork Walla Walla was initiated as an additional action that could be implemented to meet Tribal harvest expectations and eventually create a population of spring Chinook that were adapting to local conditions of the Walla Walla River. The hatchery is expected to become operational in 2021. The ISRP reviewed the Hatchery Master Plan in 2013 and also the program’s Monitoring and Evaluation Plan in 2015 and 2018. The 2018 review (ISRP 2018-9) resulted in a “Meets Scientific Criteria with Qualifications.” The qualifications fell into two categories, assessments of within hatchery performance (2+ qualifications), and evaluations of post-release performance (6 qualifications). These qualifications and other issues (data storage, release site selection, etc.) produce general confusion on how the hatchery will operate and be evaluated to meet its important role in reintroduction of spring Chinook and ultimately harvest.

In future annual reports and work plans, the proponents need to provide information to address the following Conditions:

1. M&E responsibilities. The proponents indicate that hatchery staff supported by this project (200003802 Walla Walla Hatchery O&M) will evaluate within-hatchery performance while project 200003900 (Walla Walla River Basin Monitoring and Evaluation (M&E) personnel will assess post-release performance and the ecological/biological effects of the hatchery’s smolt releases. Ultimately, the metrics of these M&E activities should be presented in work plans and annual reports.

2. Production protocols. Questions raised by the ISRP regarding broodstock monitoring and holding, spawning procedures, incubation conditions, rearing methods, and fish release protocols in the 2018 review were partially addressed in the proposal. However, from the information that the ISRP has reviewed, it does not appear that key decisions for how the hatchery will be operated have been addressed. For example, gametes from adults captured at the Nursery Bridge trap (Walla Walla River) as well as adults obtained at Three Mile Dam (Umatilla River) will be used to reach the egg take goal of the hatchery. It is unclear what decision rules will be employed to coordinate egg takes at these two different sources. Presumably, to achieve a locally adapted stock, eggs from the Umatilla subbasin would only be imported to the hatchery on an as needed (infrequent) basis, but this is never mentioned. Spawning is expected to occur weekly, and the plan is to use adults throughout the entire run. What steps will be taken to adjust developmental rates in eggs collected at different times and places (NBD and TMD) to ensure that groups of juveniles can be simultaneously ponded and reared at desired densities? Can the hatchery cool incubation waters to adjust developmental rates to create such coordination or will other methods be used?

3. Production assumptions. The objectives for the number of adult pairs (175) and jacks (17) needed to reach the hatchery’s green egg take goal are clear but the underlying assumptions about fecundity and expected survival do not lead easily to these numbers. One hundred and sixty-five pairs are expected to produce 925,000 green eggs and 860,000 eyed eggs. Yet, average fecundity is stated to be 3,800 eggs. Given this fecundity value, these fish would produce 627,000 green eggs not 925,000. At spawning, single pair crosses are planned. No mention is made of how jacks may be incorporated into their proposed breeding scheme. Instead, it is suggested that males > 900 mm will be used repeatedly as sires. No rationale for this decision is presented or how the multiple use of single males may affect adult collection numbers, sex ratios, and ultimately effective number of breeders.

4. Pathogen monitoring. Bacterial Kidney Disease is an important pathogen in Chinook salmon, and the proponents propose culling egg lots from females based on ELISA optical density values (OD) to control its presence. Yet, they plan on sampling just 60 females or ~36% of their female broodstock. To be effective, ELISA OD values should be obtained on every spawned female and an agreed upon OD value for culling should be established.

5. SMART objectives. The proponents along with the hatchery’s manager need to produce an annual hatchery operation plan that describes the tasks and criteria that address the above and related questions. The plan should contain explicit SMART objectives (see proposal instructions) that cover all aspects of hatchery operations along with an accompanying adaptive management process. Much of what is needed is already in the proponent’s monitoring and evaluation plan (e.g., Table 14) and their proposal. This plan can be incorporated into the project’s next annual report.

Q1: Clearly defined objectives and outcomes

The overall purpose of the Walla Walla spring Chinook hatchery program is clearly presented in the proposal. Although the overall purpose of the new hatchery is well described, specific fish cultural objectives are not presented. Because the hatchery will not begin full operation until 2022, time is still available to develop such criteria. As indicated in the general comments section of this review, the proponents have developed explicit quantitative objectives for many of the hatchery’s operations. They will become essential components of the hatchery’s adaptative management procedure. These standards should be presented as “SMART” objectives and need to cover all aspects of the hatchery’s fish cultural operations. Having an easily identified list of SMART objectives embedded in an annual hatchery operations plan will allow the proponents to readily assess whether desired end points are being reached. As the hatchery continues to operate these standards can be adjusted and initial methods can also be modified as needed.

Q2: Methods

Generally, the methods described to perform fish cultural and routine hatchery operations and broodstock collection are appropriate. There are a few instances, however, where the proponents may wish to consider alternative methods to those described in their proposal and M&E plan. In past reviews, the ISRP has suggested using isobuckets (as done at the Cle Elum Supplementation and Research Facility) to temporarily incubate eggs from single females to prevent BKD transmission and allow the culling of egg lots with high ELISA OD values. Horizontal transmission is prevented by this approach whereas it is still possible when eggs are placed into MariSource incubation trays because of how water moves through stack incubators.

Currently, the proponents are confident that they can identify sex for prospective broodstock visually. This may well be the case. Several other spring Chinook programs in the Columbia Basin, however, are using handheld ultrasound wands to sex prospective broodstock. This has proved to be a highly accurate way to sex fish, particularly early on in a run when sexual dimorphism is not highly developed. During spawning the proponents plan on producing single pair crosses. If this approach is used, we recommend that they include backup males to help ensure high fertilization rates. Having a robust estimate of the number of green eggs spawned is a critical metric since it used to calculate survival rates at multiple life stages. The proponents plan on using a random sample of females to generate a fecundity estimate and through this relationship estimate green egg take. We suggest that fecundity estimates be made on every spawned female. Gravimetric estimates of fecundity can be rapidly made under typical hatchery operations. Making such estimates will allow the proponents to gather egg weight and quality data, and reproductive effort values. Finally, there appears to be some doubt about the usefulness of assessing precocious maturation in hatchery males. The ISRP considers this to be an important metric because the production of minijacks in spring Chinook hatcheries can be substantial. Without knowing this rate, SAR values can be biased low. Several methods can be used to acquire this type of data, including visual inspections on gonadal development on a random sample of fish just prior to, or at the time of release.

As in our earlier reviews we urge the proponents to talk with other tribal and non-tribal hatchery staff culturing spring Chinook in the Basin. Innovations and lessons learned from these ongoing hatchery programs should help the proponents craft methods and determine expected standards that can be incorporated into their SMART objectives.

Q3: Provisions for M&E

No formal adaptive management process or cycle is presented for assessing within hatchery performance. Establishment of an approach that can be followed during an annual or end of season review process is needed. Once SMART objectives have been established it should be relatively straightforward to compare observed performance with expected standards.

The proponents indicate that an Annual Operations Plan (AOP) to be co-developed by CTUIR, ODFW, and WDFW personnel will be established once the hatchery becomes fully operational. This plan appears to be largely concerned with where, when, and how hatchery reared fish should be released. If the AOP could be combined with a within hatchery operations adaptive management plan, then the project would have a comprehensive way to adjust to its challenges and opportunities.

Q4: Results – benefits to fish and wildlife

Under present environmental conditions, consistent releases of smolts from the Walla Walla Hatchery likely represent the best approach of establishing sustainable and harvestable populations of spring Chinook in the Walla Walla subbasin. Additionally, if broodstock can reliably be collected from inside the subbasin, the hatchery will also expedite the establishment of spring Chinook locally adapted to the South Fork Walla Walla and perhaps to other release locations (upper Mill Creek) as well. The project’s goals fit well within the Council’s Fish and Wildlife Program and tribal visions.