This report summarizes a survey of healthy native stocks of anadromous salmonids in the Pacific Northwest and California. We used a questionnaire approach combined with spatial analysis to describe the status and distribution of stocks considered to be in relatively good condition. These stocks now constitute a small fraction of the region's historic anadromous salmonid resource but are critical to maintaining current resource productivity. Several agencies have developed, or are in the process of developing, computerized databases that will help organize predominantly quantitative data on native stocks of anadromous salmonids. Our survey supplements those efforts by summarizing some of the knowledge of biologists familiar with the stocks and by making status assessments that at times go beyond conservative analyses of quantitative data. The survey identified 99 healthy native wild stocks of salmon and steelhead that biologists consider to be at least one‐third as abundant as would be expected without human impacts, including 20 considered at least two‐thirds as abundant. More than three‐quarters of these stocks are fall chinook, chum salmon, or winter steelhead in Puget Sound or coastal watersheds of Oregon or Washington. Fewer healthy populations remain of summer steelhead and coho, pink, and sockeye salmon and spring or summer chinook. We suggest that healthy stocks provide unique opportunities for conservation and research that are at least as important to the future of the region's anadromous salmonids as those associated with at‐risk stocks.

To estimate the parameters that govern mass‐ and temperature‐dependent growth, we conducted a meta‐analysis of existing growth data from juvenile Chinook Salmon Oncorhynchus tshawytscha that were fed an ad libitum ration of a pelleted diet. Although the growth of juvenile Chinook Salmon has been well studied, research has focused on a single population, a narrow range of fish sizes, or a narrow range of temperatures. Therefore, we incorporated the Ratkowsky model for temperature‐dependent growth into an allometric growth model; this model was then fitted to growth data from 11 data sources representing nine populations of juvenile Chinook Salmon. The model fit the growth data well, explaining 98% of the variation in final mass. The estimated allometric mass exponent (b) was 0.338 (SE = 0.025), similar to estimates reported for other salmonids. This estimate of b will be particularly useful for estimating mass‐standardized growth rates of juvenile Chinook Salmon. In addition, the lower thermal limit, optimal temperature, and upper thermal limit for growth were estimated to be 1.8°C (SE = 0.63°C), 19.0°C (SE = 0.27°C), and 24.9°C (SE = 0.02°C), respectively. By taking a meta‐analytical approach, we were able to provide a growth model that is applicable across populations of juvenile Chinook Salmon receiving an ad libitum ration of a pelleted diet.Received May 20, 2014; accepted December 4, 2014

This study developed a stochastic life cycle model to simulate idealized supplementation strategies to investigate the following question: under what circumstances could hatchery fish stocking contribute to the recovery of Oregon coast coho salmon (Oncorhynchus kisutch)? Simulations were used to find a solution space, defined by the attributes of wild and hatchery-bred salmon, their offspring, and their environments, where hatchery fish could supplement natural production without further depressing it until natural or human factors restricting production were relieved. These simulations suggest that short-duration, tightly controlled, low-intensity conservation hatchery programs designed to minimize genetic and ecological risks may yield minor short-term increases in adult coho salmon abundance while posing significant ecological and genetic risks. No solution space was found that indicated clear long-term benefits from such a supplementation program. Of all the management actions modeled, habitat restoration offered by far the largest and only permanent gains in coho salmon abundance while posing no genetic or ecological risk to the fish. The modeled benefits of habitat restoration were significant regardless of assumptions made about the fitness of hatchery fish and their offspring.

Interactions between hatchery-origin and wild anadromous salmonids, and their potential influence on the productivity of wild fish, are often a concern of those trying to maintain or recover natural populations. The concern stems from the large size and broad geographic scope of existing hatchery programs, increased emphasis on the use of hatcheries to enhance natural production for recovery, and recognition that the programs may be having consequential effects on wild salmonids. Answers to questions about the magnitude of such effects on individual programs or populations are often pursued but frequently unavailable. This makes it important in the instances in which answers are developed that they be reliable.The purpose of Lister (2014) was "to determine the influence of hatchery steelhead [Oncorhynchus mykiss] spawners on productivity of natural steelhead spawners in mixed populations that included adults of hatchery and natural origin." In pursuit of this, the paper presents results that are dependent on confounded methods and unsupported assumptions as a basis for suggesting that hatchery-origin spawners (S h ) have not negatively influenced the natural productivity of multiple steelhead populations in the interior Columbia River basin. The paper has at least three critical flaws: the analytic approach, the use of a measure of productivity for natural fish that is inherently flawed, and the drawing of erroneous conclusions from irresolute data.The paper has additional technical shortcomings that we have chosen not to address here, particularly with regard to how specific data estimation errors and biases (other than those of the flawed productivity metric) have or have not been addressed. ANALYTIC APPROACHPast analyses of spawner-recruit data that examined the influences of hatchery-origin salmonids on the productivity of naturally spawning populations have typically relied on meta-analytic techniques, multivariate modeling approaches, or both (Chilcote 2003;Nickelson 2003;Kostow and Zhou 2006;Buhle et al. 2009;Chilcote et al. 2011Chilcote et al. , 2013. A key reason such approaches were taken is their statistical power to discern patterns in data that exhibit high variability.Lister (2014) takes an alternate analytic approach. The paper focuses on the presence or absence of statistically discernable differences in productivity between three specific pairs of hatchery-affected (mixed-treated) and littleaffected (reference) steelhead populations. However, there are no before-and-after statistical evaluations of the influence of S h on the mixed populations, as are performed under before-after control-impact paired study designs (Stewart-Oaten et al. 1986) and no true experimental controls. The paper's pairwise comparisons are instead dependent on an unverified assumption that populations within the selected pairs would have similar productivities (identical or very nearly so) absent hatchery influence. This assumption is suspect because the productivities of steelhead populations are affected by a variety of ...

No abstract