Salmon life histories are finely tuned to local environmental conditions, which are intimately linked to climate. We summarize the likely impacts of climate change on the physical environment of salmon in the Pacific Northwest and discuss the potential evolutionary consequences of these changes, with particular reference to Columbia River Basin spring/summer Chinook (Oncorhynchus tshawytscha) and sockeye (Oncorhynchus nerka) salmon. We discuss the possible evolutionary responses in migration and spawning date egg and juvenile growth and development rates, thermal tolerance, and disease resistance. We know little about ocean migration pathways, so cannot confidently suggest the potential changes in this life stage. Climate change might produce conflicting selection pressures in different life stages, which will interact with plastic (i.e. nongenetic) changes in various ways. To clarify these interactions, we present a conceptual model of how changing environmental conditions shift phenotypic optima and, through plastic responses, phenotype distributions, affecting the force of selection. Our predictions are tentative because we lack data on the strength of selection, heritability, and ecological and genetic linkages among many of the traits discussed here. Despite the challenges involved in experimental manipulation of species with complex life histories, such research is essential for full appreciation of the biological effects of climate change.

To better understand and predict Oregon coho (Oncorhynchus kisutch) marine survival, we developed a conceptual model of processes occurring during four sequential periods: (1) winter climate prior to smolt migration from freshwater to ocean, (2) spring transition from winter downwelling to spring/summer upwelling, (3) the spring upwelling season and (4) winter ocean conditions near the end of the maturing coho's first year at sea. We then parameterized a General Additive Model (GAM) with Oregon Production Index (OPI) coho smolt‐to‐adult survival estimates from 1970 to 2001 and environmental data representing processes occurring during each period (presmolt winter SST, spring transition date, spring sea level, and post‐smolt winter SST). The model explained a high and significant proportion of the variation in coho survival (R2 = 0.75). The model forecast of 2002 adult survival rate ranged from 4 to 8%. Our forecast was higher than predictions based on the return of precocious males (‘jacks’), and it won't be known until fall 2002 which forecast is most accurate. An advantage to our environmentally based predictive model is the potential for linkages with predictive climate models, which might allow for forecasts more than 1 year in advance. Relationships between the environmental variables in the GAM and others (such as the North Pacific Index and water column stratification) provided insight into the processes driving production in the Pacific Northwest coastal ocean. Thus, coho may be a bellwether for the coastal environment and models such as ours may apply to populations of other species in this habitat.

Globally, there is increased scientific and public interest in the concept of ecosystem-based fisheries management (EBFM). This trend is fueled by a widespread perception that large-scale fishing operations are powerful forces altering the structure and function of marine ecosystems. It is acknowledged that management needs to better account for variations in ocean productivity, stock structure, and changing social values. Many countries are contemplating how to improve ocean fishery management. In the United States, fishery management bodies are experiencing pressure to undertake the daunting task of moving from their current single-species management plans to EBFM. Impediments include lack of a clear definition of EBFM, what it entails, or how to proceed. In this paper, characteristics of fishery management that are unique to EBFM are identified. The transition to EBFM needs to be evolutionary rather than revolutionary. A course of action is outlined that can be used to guide this transition. Modeling approaches and metrics useful for planning, implementing, and evaluating EBFM are discussed, with particular emphasis on management strategy evaluation.Résumé : Il y a, à l'échelle globale, un intérêt croissant chez les scientifiques et le public en général pour le concept de gestion des pêches axée sur les écosystèmes (EBFM, ecosystem-based fisheries management). Cette tendance est alimentée par la perception que les opérations de pêche de grande envergure constituent des forces puissantes qui altèrent la structure et le fonctionnement des écosystèmes marins. On reconnaît que l'aménagement doit mieux tenir compte des variations de la productivité océanique, de la structure des stocks et des valeurs sociales changeantes. Plusieurs pays cherchent comment améliorer la gestion des pêches dans l'océan. Aux États-Unis, les organismes responsables de la gestion des pêches subissent de fortes pressions pour remplacer leurs plans actuels axés sur les espèces individuelles par l'EBFM. Une des difficultés est l'absence de définition claire de l'EBFM; il est aussi nécessaire d'en connaître les implications et de savoir comment procéder. Nous identifions ici les caractéristiques de la gestion des pêches qui se retrouvent exclusivement dans l'EBFM. La transition vers l'EBFM doit se faire par évolution plutôt que par révolution. Nous proposons un plan d'action pour guider cette transition. Nous discutons aussi des méthodologies de modélisation et des métriques utiles pour la planification, la mise en oeuvre et l'évaluation de l'EBFM avec une attention particulière portée à l'évaluation des stratégies de gestion.[Traduit par la Rédaction] Marasco et al. 939