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Climate vulnerability can be evaluated by multiple organismal responses. We developed a climate vulnerability framework focused on growth potential of redband trout (Oncorhynchus mykiss newberri). We employed a bioenergetics model to evaluate spatial variability in growth potential in relation to constraints on body size imposed by stream flow, physiological responses linked to variable thermal regimes, and variation in physiological adaptive capacity inferred from field respirometry. Results indicate that maximum size (g) of redband trout increases with stream discharge. Growth potential is strongly linked to body size, with smaller individuals performing better relative to larger fish in cooler thermal regimes. Annual patterns of growth varied among sites and were related to body size and physiological adaptive capacity. Putatively cold-adapted fish were more likely to exhibit bimodal growth with peaks in spring and autumn, whereas warm-adapted fish exhibit a summer peak in growth potential. These findings offer insights into how climate vulnerability of stream-living fish can be conditioned on both stream flow and thermal regimes, and the potential for physiological adaptive capacity to influence vulnerability. Key words: bioenergetics, northern Great Basin, Oregon, Oncorhynchus mykiss newberri, redband trout, thermal adaptation, Introduction The effects of climate change on streams include warming temperatures and altered discharge, both of which influence sensitive coldwater species, such as salmonid fishes (Jonsson and Jonsson 2009; Kovach [...]

Pacific lamprey (Entosphenus tridentatus), a fish species native to the Pacific Northwest (USA), have distinctive cultural and ecological value but determining their spatial and temporal distribution is challenging due to a general lack systematic monitoring. In this study, we used counts of Pacific lamprey redds to model the probability of occurrence and abundance of Pacific lamprey based on environmental covariates including artificial barriers, assuming higher predicted lamprey redds translates to more suitable spawning habitats. Using generalized linear mixed zero‐inflated models, results suggest that Pacific lamprey abundance was generally lower in high gradient streams, further from the ocean. Stream reaches with warmer spring water temperatures and greater historical median spring flows supported higher abundances. Lamprey occurrence was primarily influenced by spring water temperatures and distance from the ocean. We further observed that when streams warm beyond 18°C, confidence intervals around the abundance estimates widen and zero‐inflation increases, indicating a decrease in occurrence. One objective of the study was to recommend where barrier removal or restoration should be prioritized to increase passage and thus access to upstream habitats. We considered artificial barriers to primarily influence the probability of occurrence through access. The barrier variable in this model had a negative effect on the probability of lamprey occurrence, but it was not a strong predictor in the model. While we are not able to suggest specific locations that would most benefit barrier removal or improvement based on these model results, we can identify the watersheds with a higher probability to support Pacific lamprey and provide potential additional habitats by improving habitat connectivity. Focusing restoration and/ or removal of barriers on watersheds in the Mid‐South region of the Oregon Coast (i.e., Alsea, Siuslaw, Coos, Coquille, and Sixes rivers) with higher habitat suitability could prioritize use of limited funds, increase the probability of benefiting Pacific lamprey, and potentially other native lampreys and migratory (e.g., salmon, steelhead; Oncorhynchus) species. Although this manuscript focuses on the Oregon Coast region, the methods are transferrable to other regions where Pacific lamprey are present. [ABSTRACT FROM AUTHOR]

The Oregon Coast landscape displays strong spatial patterns in air temperature, precipitation, and geology, which can confound our ability to detect relationships among land management, instream conditions, and fish at broad spatial scales. Despite this structure, we found that a suite of immutable or intrinsic attributes (e.g., reach gradient, drainage area, elevation, and percent weak rock geology of the catchments draining to each of our 423 study reaches) could explain much of the variation in pool surface area across the landscape and could contribute to an estimate of how many juvenile coho salmon (Oncorhynchus kisutch) one might expect to find in those pools. Further, we found evidence of differences in pool surface area across land ownership categories that reflect differing management histories. Our results also suggest that historical land and river management activities, in particular splash dams that occurred at least 50 years ago, continue to influence the distribution of juvenile coho salmon and their habitats today. Le paysage du littoral de l'Oregon presente un degre de structure spatiale eleve en ce qui concerne des caracteristiques du paysage comme la temperature de l'air, les precipitations et la geologie. Malgre cette structure sous-jacente, nous avons constate qu'une serie d'attributs immuables ou intrinseques comme, par exemple, le gradient des tronqons, la superficie drainee, l'elevation moyenne du bassin versant et le pourcentage de la geologie constitue de roches peu resistantes des reseaux hydrographiques se deversant dans chacun des 423 tronqons etudies, pourrait expliquer une bonne partie des variations de la superficie des fosses a l'echelle du paysage et pourrait aider a estimer le nombre de saumons cohos (Oncorhynchus kisutch) juveniles possiblement presents dans ces fosses. Nous avons egalement trouve des indices de variation de la superficie des fosses selon la categorie de propriete terrienne qui refletent differents historiques de gestion. Nos resultats donnent a penser que les activites passees de gestion des terres et des rivieres, en particulier le flottage de billots il y a au moins 50 ans, continuent a ce jour d'influencer la repartition des saumons cohos juveniles et leurs habitats. [Traduit par la Redaction], Introduction Understanding the distribution of instream habitats and the density of fish within those habitats is essential for effective watershed management and conservation of depressed fish populations. For wide-ranging species [...]

The distribution, quality, and connectivity of instream habitat can influence adult salmon occupancy and abundance patterns and alter population dynamics. In this study, we evaluated the relationships between adult coho salmon (Oncorhynchus kisutch) occupancy and abundance with instream habitat conditions, including measures of spawning gravel, habitat complexity, and juvenile rearing habitat. We used corresponding adult salmon spawning and instream habitat data collected within coastal Oregon watersheds as part of a long-term monitoring program. We modeled two processes as a function of habitat characteristics: the number of coho salmon when they were present and the occupancy probabilities of coho salmon. The results from both submodels were then combined into an estimate of total abundance at each site. Adult coho salmon occupancy was best predicted by the capacity of the habitat to support parr during the winter, complex pools, percent bedrock, and site distance to the ocean. Although lacking the predictive capacity of the occupancy model, increases in adult coho counts at sites were also influenced by the site distance to the ocean, and there is evidence that both percent gravel and complex pools may also be valuable predictors. By taking advantage of long-term datasets with broad spatial range, using an integrative approach across coho salmon life stages, and utilizing innovative Bayesian modeling techniques, this study is a unique approach to understanding a complicated ecological narrative. Combined, our results indicate the spatial distribution and proximity of spawning and rearing habitats may maximize productivity for coho salmon in coastal Oregon watersheds. La repartition, la qualite et la connectivite des habitats dans les cours d'eau peuvent influencer l'occupation par les saumons adultes et la distribution de leur abondance et modifier la dynamique de leurs populations. Nous avons evalue les relations entre l'occupation et l'abondance des saumons cohos adultes (Oncorhynchus kisutch) et des conditions relatives a l'habitat dans le cours d'eau, y compris des mesures du gravier utilise pour le frai, de la complexite de l'habitat et de l'habitat d'elevage des juveniles. Nous avons utilise des donnees correspondantes sur le frai de saumons adultes et sur l'habitat dans le cours d'eau recueillies dans des bassins versants cotiers de l'Oregon dans le cadre d'un programme de surveillance a long terme. Nous avons modelise deux processus en fonction des caracteristiques de l'habitat, soit le nombre de saumons cohos quand ces derniers etaient presents et les probabilites d'occupation par des saumons cohos. Les resultats des deux sous-modeles ont ensuite ete combines pour obtenir une estimation de l'abondance totale dans chaque site. La capacite de l'habitat de supporter les tacons durant l'hiver, la presence de fosses complexes, le pourcentage de substrat rocheux en place et la distance separant le site de l'ocean etaient les meilleurs predicteurs de l'occupation par des saumons cohos adultes. Si elles n'ont pas la capacite de prediction du modele d'occupation, les augmentations du nombre des saumons cohos adultes dans les sites etaient egalement influencees par la distance par rapport a l'ocean, et les resultats indiquent que le pourcentage de gravier et les fosses complexes pourraient aussi constituer des predicteurs utiles. En combinant l'utilisation d'ensembles de donnees de longue duree a grande couverture spatiale, une approche integree couvrant les differentes etapes du cycle de vie du saumon coho et des methodes de modelisation bayesiennes novatrices, l'etude constitue une approche singuliere pour mieux comprendre une situation ecologique complexe. Nos resultats combines indiquent que la repartition spatiale et la proximite des habitats de frai et d'elevage pourraient maximiser la productivite du saumon coho dans les bassins versants cotiers de l'Oregon. [Traduit par la Redaction], Introduction Salmonids have complex life histories, utilizing distinct habitats at each life stage. Stream reaches that provide sufficient habitat for each coho salmon (Oncorhynchus kitsutch) life stage (adequate spawning gravels, [...]