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This paper presents preliminary results of a study to evaluate the potential utility of supplementation of natural origin coho salmon (Oncorhynchus kisutch) on the Clearwater River, a tributary of the Queets River in western Washington. The study, initiated in 1984, involves the collection of natural origin brood stock, rearing in a combination of hatchery and natural environments, and volitional releases, combined with marking and sampling of natural origin fish. Primary findings relative to five essential research questions of this study concluded that (i) smolts from supplementation returned at a lower rate than natural smolts; (ii) the reproductive efficiency (spawner to spawner) of fish taken for supplementation was higher than that for fish allowed to spawn naturally; (iii) supplemental fish successfully reproduced and the combined supplemental-natural spawning population had a high productivity; (iv) supplementation did not appear to have affected the overall reproductive performance of the population for the duration of the project; and (v) supplementation increased the overall spawner return on the Clearwater River and is required to maximize adult production, unless conditions in both freshwater and ocean environments are optimal.Résumé : Nous présentons les résultats préliminaires d'une évaluation de l'utilité potentielle des empoissonnements d'appoint de saumons coho (Oncorhynchus kisutch) d'origine naturelle dans la rivière Clearwater, un tributaire de la Queets dans l'ouest du Washington. Cette étude, initiée en 1984, implique la récolte d'un stock reproducteur d'origine naturelle, l'élevage dans une combinaison de conditions de pisciculture et de conditions naturelles et des remises à l'eau volontaires, avec en plus le marquage et l'échantillonnage des poissons d'origine naturelle. Les principaux résul-tats de l'étude concernant cinq questions fondamentales de recherche sont les suivants: (i) les saumoneaux issus des empoissonnements d'appoint ont un taux de retour inférieur à celui des saumoneaux naturels; (ii) l'efficacité reproductive (de reproducteur à reproducteur) des poissons récoltés pour l'empoissonnement est plus grande que celle des poissons qui ont pu se reproduire naturellement; (iii) les poissons ajoutés lors des empoissonnements se reproduisent avec succès et la population combinée des reproducteurs naturels et ajoutés a une forte productivité; (iv) l'empoissonnement d'appoint ne semble pas affecter la performance reproductive globale de la population dans le cadre de ce projet et (v) l'empoisonnement d'appoint accroît le retour global de reproducteurs dans la Clearwater et il est nécessaire pour maximiser la production des adultes, à moins que les conditions à la fois dans les milieux d'eau douce et de mer ne soient optimales.[Traduit par la Rédaction] Sharma et al. 437

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The Fourth National Climate Assessment (NCA4) provided the most up-to-date understanding of climate change and its effects on the Earth system and on consequences for the United States, including impacts and associated risks, along with approaches to coping with these effects. It is intended to provide guidance to decision-makers in governmental sectors while, in practice, providing guidance for nongovernmental actors. Its regional and topical chapters highlight current knowledge, uncertainties, gaps in knowledge, and emerging threats. The current knowledge and gaps can help set a research agenda to inform future national, regional, and local climate assessments and thereby support better decision-making. The evolution of the assessment, including greater diversity in participation, and more grounded research in the Northwest represents a growing and deepening engagement with more diverse participants. This shift emphasizes the importance of diversity, inclusion, and a greater acknowledgment of multiple ways of knowing, including local and Indigenous knowledge. The Northwest chapter reflects the broader shift in framing from NCA3 to NCA4 to better understand how climate impacts pose risks to things of value in each sector or region. It considers climate impacts through five broad ways in which humans relate to the environment: natural resource economy; heritage and quality of life; water, transportation, and infrastructure; health and social systems; and frontline communities. We reflect on the assessment process and identify three recommendations to improve the assessment outcomes and processes: seek new ways to 1) engage diverse authors and stakeholders and 2) value and integrate epistemic plurality and different knowledge systems, and 3) when gaps are identified, promote research or data collection efforts designed to fill those gaps. Done well, the assessment can build support and knowledge to facilitate community action, leading to broader resilience.

We examined three types of models for preseason forecasting of the abundance of Queets River coho salmon Oncorhynchus kisutch: (1) a simple model in which estimates of smolt production are multiplied by projected marine survival rates, (2) a Ricker spawner–recruitment model, and (3) a regression model relating log‐transformed adult recruitment to smolt production. Each type of model was formulated with and without environmental variables that influence production and survival. We attempted to use a nonparametric generalized additive model (GAM) to guide the selection of the environmental variables and the form of the regression model. The GAM model was derived through a stepwise selection strategy based on the Akaike information criterion. Parametric approximate models were developed for each selected GAM model, and their performance was compared with postseason estimates of abundance using three criteria: the mean absolute percentage error, the largest absolute percentage error, and the probability of being included in the 90% prediction interval. This paper shows that the GAM approach is useful in constructing forecasting models by identifying promising relationships with predictor variables and improving abundance forecasts through the incorporation of environmental variables.