1. Objectives

The proponents found that hatcheries rearing yearling Chinook (i.e., spring, summer, and fall races) are producing substantial percentages of males that mature at age-2. In some cases, greater than 50% of the males were maturing as “minijacks.” The production of these precocious parr or minijacks reduces the production of anadromous fish, may lead to deleterious ecological and genetic interactions with native fishes, and complicates (i.e., biases) the computation of important demographic metrics such as SAR, SAS, and R/S values.

The overarching goal of this project is multi-faceted: (a) accurately determine the prevalence of minijacks in hatcheries that are releasing yearling Chinook smolts, (b) discern the environmental and genetic factors responsible for early maturation in hatchery settings, and (c) develop hatchery guidelines that can be used to reduce their occurrence. The project has developed clearly defined and measurable objectives to accomplish its overarching goal.

For example, surveys have been conducted to estimate the occurrence of minijacks in a number of the Basin’s Chinook hatcheries. These assessments occurred in both segregated and integrated hatchery programs. Common garden rearing studies were performed to determine if genetic factors were influencing early male maturation rates. Moreover, the effects of multiple environmental factors on minijack prevalence (e.g., feeding rates in the autumn/winter period, lipid content in foods, water temperatures during rearing, and feeding periodicity) were examined via carefully designed experiments.

The production of minijacks is a persistent problem faced by hatchery operators that rear and release yearling Chinook salmon. The project’s objectives directly and indirectly address several Fish Propagation uncertainties identified in the Council’s 2017 Research Plan. Consequently, the objectives of this project are relevant to the Council’s Fish and Wildlife Program. Furthermore, all the objectives and work described in the project’s narrative are time-based with clear end dates.

2. Methods

The proponents are using blood plasma 11-ketotestosrone assays to detect precocious maturation in juvenile Chinook. This assay has proven to be one of the most effective methods that can be applied to detect early maturation in male salmonids. Their annual reports, peer-reviewed papers, and presentations indicate that the project’s experimental designs and statistical approaches are appropriate. The narrative states that publications associated with this effort will be completed by 2022. However, given the key findings of this effort, we suspect the project team will continue to develop new hypotheses and conduct experiments that will directly benefit hatchery management in the Basin.

3. Results

The project is meeting its objectives, testing hypotheses, and addressing a number of Fish Propagation uncertainties contained in the Council’s 2017 Research Plan. Recent results from the project indicate that: (a) a wide range (e.g., 8 -71%) of hatchery-reared male chinook salmon mature precociously as age-2 minijacks throughout the Basin, (b) integrated hatchery stocks are frequently more susceptible than segregated stocks to early male maturation, (c) different stocks reared under identical conditions display an approximate 10-fold variation in minijack proportions (range 4.3-47% of males), (d) manipulation of ration and dietary lipid to match a “wild fish template” for growth significantly reduced minijack and jack rates in yearling Fall Chinook, and (e) a rearing design that uses a “wild fish template” for growth, through use of cold-water winter rearing acclimation facilities, increased age at maturation and improved SARs in hatchery Summer Chinook salmon.

The findings from the proponent’s common garden experiments have implications regarding broodstock transfers among facilities, most notably, when adult return numbers in one basin are inadequate to meet production goals in a given year. Transferring stocks with lower thresholds for early male maturation may result in higher than expected minijack rates in progeny from these stocks. This practice may fulfill short-term production goals but result in negative long-term consequences to the program depending on the specific stock and facility.

Results of the project have been used by managers to reduce minijack production in individual hatcheries. Additionally, the surveys for minijacks at Chinook hatcheries, controlled laboratory studies, and the proponent’s hatchery production experiments have substantially increased our understanding of the genetic and environmental factors that influence early male maturation. Idiosyncratic features at individual hatcheries (e.g., water sources, stock origins, whether hatcheries are operated as segregated or integrated programs, etc.) have all been identified as elements that can affect the incidence of early male maturation. As a result, each hatchery will need to implement a customized suite of strategies to reduce the occurrence of minijacks. There is no universal strategy. Although minimizing growth in the autumn and reducing the lipid content in feeds appear to be generally useful.

Future work is being directed toward assessing the physiological consequences of the measures used to reduce the prevalence of minijacks. Determining how shifts in diet formulations, feeding rates, water temperature, and other strategies designed to limit early maturity may affect smoltification, juvenile migration behavior, overall survival, and maturation age are also important. We encourage the project to continue its investigations into these questions.

Project results are being shared with hatchery operators and through annual reports and numerous peer-reviewed publications. Results are applicable both within and outside of the Columbia Basin.

4. 2017 Research Plan uncertainties validation

The Council’s 2017 Research Plan indicates that the project is addressing Fish Propagation uncertainties. These uncertainties coincide with those mentioned by the proponents.

Comment:

This is a highly relevant and practical research project that addresses key uncertainties involving survival and maturation rates of hatchery Chinook salmon and the potential effects of hatchery supplementation on natural and hatchery production. Results from this project may be used to help develop hatchery rearing regimes that minimize early male maturation rates and improve hatchery smolt-to-adult survival rates (SARs) while minimizing negative impacts to protected natural stocks, including resident fishes. The project has important implications for implementation of segregated versus integrated hatcheries, as the latter approach tends to produce earlier maturing minijacks. Based on the findings of this project, all Chinook salmon hatcheries in the Columbia Basin should test for and estimate the production of minijacks.

1. Objectives, Significance to Regional Programs, and Technical Background

Objectives are clearly stated and quantitative with implied time limits (one generation). The biological objectives have important implications for hatchery supplementation and management, including outcomes from segregated versus integrated hatcheries. The unintentional production of precocious salmon ("minijacks") reduces the production of anadromous fish (i.e., large fish that are harvested in fisheries), may lead to deleterious ecological and genetic interactions with native fishes, and complicates (i.e., biases) the calculation of important demographic metrics such as SAR, SAS, and R/S values. The anticipated outcomes are expressed quantitatively as hypotheses to be tested. Timelines for achievement are approximately 5 years (to obtain results over one full generation).

2. Results and Adaptive Management

Some objectives have already been achieved in that hypotheses have been tested at the laboratory scale, and multiple studies have been published in journals. The project is on track to assess the feasibility and potential benefits from implementation of its findings at a larger hatchery-level scale.

The project has evolved from surveys to accurately determine the prevalence of minijacks in hatchery releases of yearling Chinook smolts, to experiments to identify the environmental and genetic factors responsible for early maturation in hatchery settings, to efforts to develop hatchery guidelines that can be used to reduce minijack production in a variety of different settings. One of the most important and unexpected finding is that integrated hatcheries tend to produce more minijacks than segregated hatcheries because segregated hatcheries select against the use of minijacks in the broodstock. We expect the project team will continue to develop new hypotheses and conduct experiments that will provide direct benefits for hatchery management throughout the Basin.

3. Methods: Project Relationships, Work Types, and Deliverables

The numerous peer-reviewed publications indicate that the project includes appropriate experimental designs, methodology, and statistical methods. The proposal provides a good overview of the hypotheses tested, methods, findings, and relationships to key Fish and Wildlife Program issues throughout the Basin.

The project is providing a major benefit to fish and wildlife simply by bringing the high frequency of minijack age 2 maturing males to light. It is a result of fish culture practice that not only biases SAR estimation but also is probably a source of domestication selection. The project scientists are well positioned to understand the problem physiologically and to evaluate fish-culture practices.

1. Purpose, Significance to Regional Programs, Technical Background, and Objectives

There are very compelling ties to regional programs and to the Council’s Fish and Wildlife Program – the proponents have identified a major problem with Chinook supplementation and offer the prospect of adaptive change of practices:

Objective 1) Improve survival and reduce fitness loss in Columbia River URB Fall Chinook salmon.

Objective 2) Refine rearing protocols to reduce minijack rates and optimize smolt development in URB Fall Chinook salmon.

Objective 3) Continue long-term minijack monitoring in Spring Chinook salmon from the Yakima River Supplementation Program.


2. History: Accomplishments, Results, and Adaptive Management

The project scientists are an experienced team with a strong record of publishing results. They have demonstrated an insidious problem and clearly describe past and future adaptive changes to fish culture practices that have occurred or will occur as a result of this research.

3. Project Relationships, Emerging Limiting Factors, and Tailored Questions for Type of Work (Hatchery, RME, Tagging)

The proposal explains how the research will affect other activities in the region, as well as serve as a model for other regions. The proponents also broach the subject of climate change and how that may contribute to the minijack problem in this and other systems.

4. Deliverables, Work Elements, Metrics, and Methods

The proposal does a great job of describing deliverables (as well as reviewing their past progress and difficulties in meeting past deliverable due dates). That candor is refreshing! The level of detail explaining methodology (both experimental and analytical) was outstanding

The project is providing a major benefit to fish and wildlife simply by bringing the high frequency of minijack age 2 maturing males to light. It is a result of fish culture practice that not only biases SAR estimation but also is probably a source of domestication selection. The project scientists are well positioned to understand the problem physiologically and to evaluate fish-culture practices. 1. Purpose, Significance to Regional Programs, Technical Background, and Objectives There are very compelling ties to regional programs and to the Council’s Fish and Wildlife Program – the proponents have identified a major problem with Chinook supplementation and offer the prospect of adaptive change of practices: Objective 1) Improve survival and reduce fitness loss in Columbia River URB Fall Chinook salmon. Objective 2) Refine rearing protocols to reduce minijack rates and optimize smolt development in URB Fall Chinook salmon. Objective 3) Continue long-term minijack monitoring in Spring Chinook salmon from the Yakima River Supplementation Program. 2. History: Accomplishments, Results, and Adaptive Management The project scientists are an experienced team with a strong record of publishing results. They have demonstrated an insidious problem and clearly describe past and future adaptive changes to fish culture practices that have occurred or will occur as a result of this research. 3. Project Relationships, Emerging Limiting Factors, and Tailored Questions for Type of Work (Hatchery, RME, Tagging) The proposal explains how the research will affect other activities in the region, as well as serve as a model for other regions. The proponents also broach the subject of climate change and how that may contribute to the minijack problem in this and other systems. 4. Deliverables, Work Elements, Metrics, and Methods The proposal does a great job of describing deliverables (as well as reviewing their past progress and difficulties in meeting past deliverable due dates). That candor is refreshing! The level of detail explaining methodology (both experimental and analytical) was outstanding

The two principal types of data compiled by this research project are smolt development physiological profiles (growth hormone levels, size, gill ATPase enzyme levels) and age-2 early male maturation (minijack) rates (11-ketotestosterone steroid levels) from fish reared either in laboratory based studies or production hatcheries.  There are no repositories for this type of data beyond the peer review literature.  This project has a strong record of publishing our findings in the peer reviewed literature.  However, there is some delay of perhaps years for multi-year studies in the collection of the samples, running of the laboratory assays, analyzing and interpreting the data.  Shorter term results can always be found in the BPA annual reports on line.  Neither of these repositories were listed as options in Taurus.   As this study has revealed, up to half of the male fish produced in some Chinook hatcheries are not smolts, but minijack maturing males. Minijack rates may be a useful metric for hatcheries to know, however to our knowledge, no hatchery program keeps track of this parameter.   Finally, in past and proposed work from this project different production rearing treatments were partially pit-tagged.  Survival and adult return data from those studies is available in Pit-taggis.  Thus, there is some indirect repository of data in that format.

This is an excellent proposal, but this project may be nearing the point of toning down the actual collection of more research data and instead developing recommendations for protocol development and implementation of existing findings. Along these lines, the work element to look at rearing practices should be emphasized.

The results of this study have broad applicability.

Technical and scientific background: The technical and scientific background for this proposal is outstanding. It gives the reader an excellent basis to understand the rest of the proposal -- not only what is proposed, but why as well.

Rationale and significance to subbasin plans and regional programs: This proposal is clearly associated with reforms to artificial production in the basin, as evidenced by this quote: "Now, the focus is on reducing or eliminating deleterious effects of hatcheries on naturally rearing fish and redesigning and adjusting hatchery programs to rear fish that are qualitatively and qualitatively similar to wild fish, not to simply rear more fish in hatcheries."

Relationships to other projects: The proposal provides excellent detail in regards to specific projects, particularly to hatchery-rearing practices throughout the basin.

Project history: The proposal includes an excellent summary of the project history over the past five years, including listing important findings with excellent and informative figures. This is an interesting project at both the academic and practical levels.

Objectives: Although the specific objectives are well defined by tasks, an overarching objective of improving our understanding of the influences of artificial culture on the life history trajectories of salmon would be appropriate.

Tasks (work elements) and methods: Methods are extremely well explained, including nice conceptual diagrams.

Monitoring and evaluation: Evaluation has been provided in the past, and will likely continue in the future, to provide important insights into altering artificial production to make it compatible with populations of natural salmon.

Facilities, equipment, and personnel: Facilities have already been shown to be more than adequate.

Information transfer: Publication record is excellent, that is likely best outlet, although direct input into other programs would be good.

Benefits to focal and non-focal species: The project should provide benefits to both natural and hatchery populations of the focal species. There should be no adverse effect beyond interactions during data collections.