About
402
Publications
109,353
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
20,696
Citations
Publications
Publications (402)
Juvenile Pacific salmon (Oncorhynchus spp.) use estuary habitats to varying degrees with some species and populations thought to rely heavily on these areas for early growth. In the Fraser River, British Columbia, there are 18 distinct conservation units of Chinook salmon (O. tshawytscha), and all but one is of conservation concern. Our study compa...
A major challenge in contemporary aquatic environmental management is anticipating and responding to increasing social-ecological uncertainty and shifts in the health of managed species. Signals indicate that many wild North American Pacific salmon populations are in or at risk of decline, but the mechanisms affecting salmon resilience are not clea...
To facilitate the movement and processing of timber in some regions of the Pacific Northwest, logs are tied together to form large rectangular rafts (often called “booms”) which are transported and stored in aquatic environments. In the lower Fraser River, British Columbia, some reaches have >50% of shoreline with adjacent log booms, yet our unders...
Female Pacific salmon often experience higher mortality than males during their once-in-a-lifetime up-river spawning migration, particularly when exposed to secondary stressors (e.g. high temperatures). However, the underlying mechanisms remain unknown. One hypothesis is that female Pacific salmon hearts are more oxygen-limited than males and are l...
Passive integrated transponder (PIT) technology is a leading tool for tracking fish in freshwater systems. PIT is highly applicable for assessing fish passage at anthropogenic infrastructure (e.g., dams and floodgates); however, there are often complications in operating PIT antennas near these structures due to the ambient electromagnetic interfer...
Estimating the survival probability of animals released from fisheries can improve the overall understanding of animal biology with implications for fisheries management, conservation and animal welfare. Vitality indicators are simple visual measures of animal condition that change in response to stressors (like fisheries capture) and can be assess...
Understanding the factors driving the spatial distribution of infectious agents in populations is key to predicting infectious agent distributions under future ecological and anthropogenic scenarios. We applied a geostatistical analysis to a data set of 59 infectious agents assayed in thousands of Chinook and coho salmon in their first marine year...
Climate change is affecting freshwater systems, leading to increased water temperatures, which is posing a threat to freshwater ecological communities. In the Nechako River, a water management program has been in place since the 1980s to maintain water temperatures at 20°C during the migration of Sockeye salmon. However, the program's effectiveness...
Background
Ecological and physical conditions vary with depth in aquatic ecosystems, resulting in gradients of habitat suitability. Although variation in vertical distributions among individuals provides evidence of habitat selection, it has been challenging to disentangle how processes at multiple spatio-temporal scales shape behaviour.
Methods
W...
Objective
Hatcheries are used to help supplement populations of Pacific salmon Oncorhynchus spp. for conservation and fisheries purposes and to provide stewardship opportunities. In British Columbia, small community‐run hatcheries typically focus on the latter and generally do not know the efficacy of their release approaches, unlike larger product...
Aquatic systems are warming and exceeding upper thermal limits (UTLs) for many fish species, yet understanding how they inform resilience to climate change is challenging. Using Pacific salmon ( Oncorhynchus spp.) as a model, we conducted a systematic review involving 168 papers investigating UTL in five species. We found considerable variation in...
Climatic warming elevates mortality for many salmonid populations during their physically challenging up-river spawning migrations, yet, the mechanisms underlying the increased mortality remain elusive. One hypothesis posits that a cardiac oxygen insufficiency impairs the heart’s capacity to pump sufficient oxygen to body tissues to sustain up-rive...
Understanding the adaptive potential of populations and species is pivotal for minimizing the loss of biodiversity in this era of rapid climate change. Adaptive potential has been estimated in various ways, including based on levels of standing genetic variation, presence of potentially beneficial alleles, and/or the severity of environmental chang...
Bull trout ( Salvelinus confluentus ) research has historically focused on highly impacted systems or occurred in a reactionary manner following overharvest. Here, we used telemetry and multi‐state capture–recapture modelling to inform management decision‐making for this highly migratory, conservation‐listed species in British Columbia's upper Fras...
Remote sensing technology offers the ability to derive information on freshwater fish habitats across broad geographic areas and has the potential to transform approaches to monitoring. However, the numerous platforms, sensors and analytical software that are available may overwhelm those interested in utilizing this important technology and thus l...
Abstract Instream barriers remain ubiquitous threats to freshwater species and their habitats. Decisions regarding barrier removal are often aimed at maximizing habitat area and connectivity for freshwater fish; yet can be challenging due to the sheer number of barriers, uncertainty in species presence, abundance, and habitat quality, as well as li...
Objective
Seaward migration and early marine residence are periods of high mortality in the lifecycle of Pacific salmon Oncorhynchus spp. The conservation of these species requires knowledge of habitat use patterns during early life to address survival bottlenecks. Using new miniaturized transmitters (V3 307‐kHz tag; Innovasea Systems), we investig...
While populations of other migratory salmonids suffer in the Anthropocene, pink salmon ( Oncorhynchus gorbusca Salmonidae) are thriving, and their distribution is expanding both within their natural range and in the Atlantic and Arctic following introduction of the species to the White Sea in the 1950s. Pink salmon are now rapidly spreading in Euro...
Metabolic scope represents the aerobic energy budget available to an organism to perform non‐maintenance activities (e.g., escape a predator, recover from a fisheries interaction, compete for a mate). Conflicting energetic requirements can give rise to ecologically relevant metabolic trade‐offs when energy budgeting is constrained. The objective of...
The early marine life of Pacific salmon is believed to be a critical period limiting population-level survival. Recent evidence suggests that some infectious agents are associated with survival but linkages with underlying physiological mechanisms are lacking. While challenge studies can demonstrate cause and effect relationships between infection...
During spawning migrations, adult Pacific salmon (Onco rhynchus spp.) must undergo a suite of morphological and physiological changes to prepare for spawning. Modern genomics approaches can be used to conduct nonlethal assessments of physiology and infectious agent presence in migrating salmon. We investigated gene expression changes and shifts in...
We investigated the physical habitat associations and movement of sympatric rainbow trout (Oncorhynchus mykiss) and Dolly Varden char (Salvelinus malma) during summer in five tributary streams of the Upper Nahmint River, British Columbia, Canada. The ecology of juvenile salmonids is well-studied, but studies involving these species in sympatry are...
Climate change is causing large declines in many Pacific salmon populations. In particular, warm rivers are associated with high levels of premature mortality in migrating adults. The Fraser River watershed in British Columbia, Canada, supports some of the largest Chinook salmon (Oncorhynchus tshawytscha) runs in the world. However, the Fraser Rive...
Although infectious agents can act as strong population regulators, knowledge of their spatial distributions in wild Pacific salmon is limited, especially in the marine environment. Characterizing pathogen distributions during early marine residence, a period considered a survival bottleneck for Pacific salmon, may reveal where salmon populations a...
Substantial, acute mortality was observed in wild-caught Chinook salmon ( Oncorhynchus tshawytscha ) of various ages and sizes, from sub-adults to returning adults, held in tanks during two holding studies carried out in August and September 2022 at the Bamfield Marine Sciences Centre (BMSC), in Bamfield, British Columbia, Canada. Within days of ca...
Female-biased mortality has been consistently reported in Pacific salmon during their adult upriver migration. We collected coho salmon (Oncorhynchus kisutch (Walbaum, 1792)) upon arrival at their spawning grounds to test whether females are more prone to cardiac oxygen limitations following exercise stress. We used a surgical approach to periodica...
For many freshwater and diadromous fishes, dams create a significant conservation challenge by fragmenting migratory routes, modifying habitats and altering patterns of water movement. Despite advances in fish passage strategies and infrastructure, passage can still be delayed or prevented. Fish can experience a variety of physiological issues as a...
Annual migrations by juvenile Pacific salmon Oncorhynchus spp. smolts are predictable, presenting opportunities for predators to exploit these seasonal prey pulses. Directly observing predator–prey interactions to understand factors affecting predation may be possible via dual‐frequency identification sonar (DIDSON) acoustic imaging. Within Chilko...
Pacific salmon (Oncorhynchus spp.) support coastal and freshwater ecosystems, economies and cultures, but many populations have declined. We used priority threat management (PTM), a decision‐support framework for prioritizing conservation investments, to identify management strategies that could support thriving populations of wild salmon over 25 y...
Two hypotheses were tested concerning the consequences to adult sockeye salmon (Oncorhynchus nerka) of escape from commonly used fishing gear (gillnet, seine net and tangle net). First, by experimentally exposing 214 fish to three commonly used fishing gear types (gillnets, tangle nets, or seine nets) and releasing to complete migration after PIT-t...
Recent decades have seen an increased appreciation for the role infectious diseases can play in mass mortality events across a diversity of marine taxa. At the same time many Pacific salmon populations have declined in abundance as a result of reduced marine survival. However, few studies have explicitly considered the potential role pathogens coul...
In response to colonial research paradigms that have subjugated Indigenous Peoples, knowledges, lands, and waters, Indigenous research methodologies have emerged to center Indigenous visions and voices in research practice. Here, we employ such methodologies to improve collective understanding of the state and future of wild Pacific salmon (Oncorhy...
Understanding changes in salmonid populations and their habitat is a critical issue given changing climate, their importance as a keystone species, and their cultural significance. Terrain features such as slope, gradient, and morphology, as well as forest structure attributes including canopy cover, height, and presence of on ground coarse wood, a...
Energy depletion is a significant concern for animals that migrate long distances on fixed energy budgets. Migrating adult Fraser River sockeye salmon (Oncorhynchus nerka) cease feeding in the ocean and are entirely reliant on endogenous energy stores to successfully complete their subsequent freshwater migration and spawn. Most research on adult s...
Dead animals may be an important or the only source of tissues to analyze for stable isotopes, with the goal of making inferences about an animal’s past ecological history. However, in nature, stable isotope values may be affected by myriad decomposition processes, such as abiotic environmental conditions and bacterial and fungal decay, potentially...
[This corrects the article DOI: 10.1093/conphys/coab016.].
Many of the world’s rivers are dammed, altering the physiology, behaviour, ecology and survival of fish. Integrative research has the potential to improve our understanding of these impacts and could enable environmental managers to develop effective solutions for population conservation. Such approaches, however, are not yet prevalent. We use a ca...
Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handli...
Hydrodynamics in dam tailraces can influence the swimming behavior and survival of fish, and yet there have been few studies that have linked the movement patterns of fish to encountered flow patterns. In this study, we examined the flow field downstream of Seton Dam in British Columbia, Canada using acoustic Doppler current profilers (ADCPs), and...
Loss of connectivity caused by anthropogenic barriers is a key threat for migratory freshwater species. The anadromous life history of salmonids means that barriers on streams can decrease the amount of habitat available for spawning and rearing. To set appropriate targets for restoration, it is important to know how different populations have been...
Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handli...
Effective management of freshwater fish habitat is essential to supporting healthy aquatic ecosystems and sustainable fisheries. In Canada, recent changes to the Fisheries Act enhanced the protection of fish habitat, but application of those provisions relies on sound scientific evidence. We employed collaborative research prioritization methods to...
The role that open‐net‐pen farms for Atlantic Salmon Salmo salar play in the global decline of stocks of wild salmonids (Salmo spp. and Oncorhynchus spp.) is contentious; Canada’s west coast is no exception. We identified the proportion of acoustic‐tagged juvenile Sockeye Salmon Oncorhynchus nerka migrating through the main migration routes of the...
Predation risk for animal migrants can be impacted by physical condition. Although size- or condition-based selection is often observed, observing infection-based predation is rare due to the difficulties in assessing infectious agents in predated samples. We examined predation of outmigrating sockeye salmon ( Oncorhynchus nerka ) smolts by bull tr...
In recent decades, the relative proportion of female sockeye salmon (Oncorhynchus nerka) on spawning grounds of several British Columbia populations has declined. Coincident with the decline has been large changes to oceanic, estuarine, and river migration environments. Over the past 30 years, numerous telemetry tracking and laboratory studies have...
Although telemetry is commonly used to study fishes, researchers rarely design experiments that facilitate in situ quantification of tagging-related impacts to survival. We experimentally applied high (mean burden = 9.6%) and low (2.6%) acoustic tag burdens and gill clip biopsies to migrating juvenile sockeye salmon (Oncorhynchus nerka). Mortality...
Pacific salmon undertake iconic homeward migrations where they move from ocean feeding grounds to coastal rivers where they return to natal spawning sites. However, this migration is physiologically challenging as fish have to navigate past predators, nets, hooks, and dams while dealing with variable flows, warm water temperatures, and pathogens. T...
Abstract Throughout history, humans have settled in areas of high biodiversity. Today these areas are home to our biggest urban centers with biodiversity at increasing risk from escalating cumulative threats. Identifying the management strategies to conserve species within such regions, and ensuring effective governance to oversee their implementat...
Increasingly, fisheries researchers and managers seek or are compelled to “bridge”
Indigenous knowledge systems with Western scientific approaches to understanding
and governing fisheries. Here, we move beyond the all-too-common narrative about
integrating or incorporating (too often used as euphemisms for assimilating) other
knowledge systems into...
Although it is assumed that the outcomes from scientific research inform management and policy, the so‐called knowledge–action gap (i.e., the disconnect between scientific knowledge and its application) is a recognition that there are many reasons why new knowledge is not always embraced by knowledge users. The concept of knowledge co‐production ha...
Numerous laboratory and field studies have found that female Pacific salmon have higher mortality than males during their once-in-a-lifetime upriver spawning migration. However, the proximate cause(s) of this increased mortality are poorly understood. This study exposed sockeye salmon (Oncorhynchus nerka) to a mild capture and tagging stressor and...
Telemetry is a common tool for studying the behavior and fate of migrating adult Pacific salmon Oncorhynchus spp., yet few field studies have compared behavior and fate associated with different tagging techniques. In this study, adult Harrison River (British Columbia) Sockeye Salmon O. nerka were captured in their natal river near spawning areas,...
Female-biased mortality has been repeatedly reported in Pacific salmon during their upriver migration in both field studies and laboratory-holding experiments, especially in the presence of multiple environmental stressors, including thermal stress. Here we used coho salmon (Oncorhynchus kisutch) to test whether females exposed to elevated water te...
Migrations of juvenile salmon smolts are generally high‐risk, with predation often implicated in reduced survival. In theory, smolts can maximise survival via depensation, or synchronising movements to swamp predators. Depensation, however, is difficult to assess in the wild. Accounting for depensation could also generate more realistic telemetry‐b...
For Pacific salmon captured and released by fisheries, post-release behaviour and survival may be influenced by their health and condition at time of capture. We sought to characterize the interactions between infectious agent burden, fish immune and stress physiology and fisheries stressors to investigate the potential for capture-mediated pathoge...
Both laboratory and field respirometry are rapidly growing techniques to determine animal performance thresholds. However, replicating protocols to estimate maximum metabolic rate (MMR) between species, populations, and individuals can be difficult, especially in the field. We therefore evaluated seven different exercise treatments-four laboratory...
[This corrects the article DOI: 10.1093/conphys/coz095.].
Synopsis
Researchers have surmised that the ability to obtain dominance during reproduction is related to an individual’s ability to better sequester the energy required for reproductive behaviors and develop secondary sexual characteristics, presumably through enhanced physiological performance. However, studies testing this idea are limited. Usin...
Adult female Pacific salmon can have higher migration mortality rates than males, particularly at warm temperatures. However, the mechanisms underlying this phenomenon remain a mystery. Given the importance of swimming energetics on fitness, we measured critical swim speed, swimming metabolism, cost of transport, aerobic scope (absolute and factori...