Erika Jennifer Eliason

• PhD
• Professor (Associate) at University of California, Santa Barbara

Global climate change is increasing thermal variability in coastal marine environments and the frequency, intensity and duration of marine heatwaves. At the same time, food availability and quality are being altered by anthropogenic environmental changes. Marine ectotherms often cope with changes in temperature through physiological acclimation, wh...

Critical thermal maxima methodology (CTM) has been used to infer acute upper thermal tolerance in fishes since the 1950s, yet its ecological relevance remains debated. In this study, the authors synthesize evidence to identify methodological concerns and common misconceptions that have limited the interpretation of critical thermal maximum (CTmax;...

Introduction Changes in temperature can fundamentally transform how species interact, causing wholesale shifts in ecosystem dynamics and stability. Yet we still have a limited understanding of how temperature-dependence in physiology drives temperature-dependence in species-interactions. For predator-prey interactions, theory predicts that increase...

Given limited resources for wildlife conservation paired with an urgency to halt declines and rebuild populations, it is imperative that management actions are tactical and effective. Mechanisms are about how a system works and can inform threat identification and mitigation such that conservation actions that work can be identified. Here, we call...

Variation in behavior within marine and terrestrial species can influence the functioning of the ecosystems they inhabit. However, the contribution of social behavior to ecosystem function remains underexplored. Many coral reef fish species provide potentially insightful models for exploring how social behavior shapes ecological function because th...

Global climate change is increasing thermal variability in coastal marine environments and the frequency, intensity, and duration of marine heatwaves. At the same time, nutritional resources are being altered by anthropogenic environmental changes. Marine ectotherms often cope with changes in temperature through physiological acclimation, which can...

It is widely regarded that we have entered a new epoch distinct from the Holocene which is defined by the dominance of humans—termed the “Anthropocene.” Indeed, for centuries humans have altered aquatic ecosystems by degrading habitats, altering ecosystem structure, and impairing ecosystem function. In the Anthropocene, aquatic ecosystems and their...

The cardiorespiratory system distributes oxygen and other factors (nutrients, wastes, hormones etc.) around the body and thus plays a central role in mediating many physiological processes such as digestion, locomotion, and reproduction. Building from a rich body of foundational research, cardiorespiratory physiology techniques are now being used f...

The typical fish cardiovascular system comprises four major parts: a heart, blood vessels, blood, and control systems. Most water-breathing fishes have a closed, single-circuit circulatory system in which blood flows in a loop from the heart, through the gills, to the peripheral tissues, and back to the heart (Figure 10.1). Air-breathing fishes hav...

Fish physiological performance is directly regulated by their thermal environment. Intraspecific comparisons are essential to ascertain the vulnerability of fish populations to climate change and to identify which populations may be more susceptible to extirpation and which may be more resilient to continued warming. In this study, we sought to eva...

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...

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...

Although most animals live in complex, thermally variable environments, the impact of this variability on specific physiological systems is still unresolved. The ectotherm heart is known to change in both structure and function to ensure appropriate oxygen delivery under different thermal regimes, but the plasticity of the upper thermal limits of t...

[This corrects the article DOI: 10.1093/conphys/coab016.].

The vertebrate circulatory system consists of a central pump (the heart), a system of tubes (the vascular and lymphatic vessels), fluid (blood and lymph) and a control system (neural, endocrine, paracrine and autocrine factors) that serves to transport gases, nutrients and other substances around the body. Key Concepts • Gases, nutrients, immune...

Thermal acclimation is a key process enabling ectotherms to cope with temperature change. To undergo a successful acclimation response, ectotherms require energy and nutritional building blocks obtained from their diet. However, diet is often overlooked as a factor that can alter acclimation responses. Using a temperate omnivorous fish, opaleye (Gi...

During spawning, adult Pacific salmonids ( Oncorhynchus spp . ) complete challenging upriver migrations during which energy and oxygen delivery must be partitioned into activities such as locomotion, maturation and spawning behaviours under the constraints of an individual's cardiac capacity. To advance our understanding of cardiac function in free...

Salmonids are some of the most widely studied species of fish worldwide. They span freshwater rivers and lakes to fjords and oceans; they include short‐ and long‐distance anadromous migrants, as well as partially migratory and non‐migratory populations; and exhibit both semelparous and iteroparous reproduction. Salmonid life‐history strategies repr...

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...

Light pollution is a rapidly growing threat to biodiversity, with many unknown or poorly understood effects on species and ecosystems spanning terrestrial and aquatic environments. Relative to other taxa, the effects of artificial light at night on aquatic invertebrates are poorly understood, despite the abundance and integral significance of inver...

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...

Intraspecific variation in key traits such as tolerance of warming can have profound effects on ecological and evolutionary processes, notably responses to climate change. The empirical evidence for three primary elements of intraspecific variation in tolerance of warming in fishes is reviewed. The first is purely mechanistic that tolerance varies...

Metabolic costs associated with parasites should not be limited to established infections. Even during initial exposure to questing and attacking parasites, hosts can enact behavioural and physiological responses that could also incur metabolic costs. However, few studies have measured these costs directly. Hence, little is known about metabolic co...

The ability to properly identify species present in a landscape is foundational to ecology and essential for natural resource management and conservation. However, many species are often unaccounted for due to ineffective direct capture and visual surveys, especially in aquatic environments. Environmental DNA metabarcoding is an approach that overc...

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...

Blood sampling through the caudal vasculature is a widely used technique in fish biology for investigating organismal health and physiology. In live fishes, it can provide a quick, easy and relatively non‐invasive method for obtaining a blood sample (cf. cannulation and cardiac puncture). Here, a general set of recommendations are provided for opti...

Teaching can be a rewarding, yet challenging, experience for early career researchers (ECRs) in fields like ecology and evolution. Much of this challenge arises from the reality that ECRs in ecology and evolution typically receive little, if any, pedagogical training or advice on how to balance teaching, research (which can include extended field w...

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.].

In the original article, there was a mistake in the legend for Figure 1 as published. After publication, it was brought to the authors’ attention that DEIMS-SDR also included not-LTER sites (Wohner et al., 2019) and the so called LTER “parent sites,” at the same hierarchical level of the research sites they are made of, generating some duplicates....

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...

Pacific salmon routinely encounter stressors during their upriver spawning migration, which have the potential to influence offspring through hormonally-mediated maternal effects. To disentangle genetic vs. hormonal effects on offspring swimming performance, we collected gametes from three species of Pacific salmon (Chinook, pink and sockeye) at th...

Acute elevation of cortisol via activation of the hypothalamic-pituitary-interrenal (HPI) axis aids the fish in dealing with a stressor. However, chronic elevation of cortisol has detrimental effects and has been studied extensively in lab settings. However, data pertaining to wild teleosts are lacking. Here, we characterized the metabolic conseque...

Species invasions threaten global biodiversity, and physiological characteristics may determine their impact. Specific dynamic action (SDA; the increase in metabolic rate associated with feeding and digestion) is one such characteristic, strongly influencing an animal's energy budget and feeding ecology. We investigated the relationship between SDA...

Understanding the threats to global biodiversity and ecosystem services posed by human impacts on coastal and marine environments requires the establishment and maintenance of ecological observatories that integrate the biological, physical, geological, and biogeochemical aspects of ecosystems. This is crucial to provide scientists and stakeholders...

As an example of applying the evidential approach to statistical inference, we address one of the longest standing controversies in ecology, the evidence for, or against, a universal metabolic scaling relationship between metabolic rate and body mass. Using fish as our study taxa, we curated 25 studies with measurements of standard metabolic rate,...

Temporally consistent individual differences in behavior impact many ecological processes. We simultaneously examined the effects of individual variation in prey activity level, covering behavior, and body size on prey survival with predators using an urchin–lobster system. Specifically, we tested the hypothesis that slow‐moving purple sea urchins...

Migration is a widespread but highly diverse component of many animal life histories. Fish migrate throughout the world's oceans, within lakes and rivers, and between the two realms, transporting matter, energy, and other species (e.g., microbes) across boundaries. Migration is therefore a process responsible for myriad ecosystem services. Many hum...

Temporally consistent individual differences in behavior impact many ecological processes. We simultaneously examined the effects of individual variation in prey activity level, covering behavior, and body size on prey survival with predators using an urchin-lobster system. Specifically, we tested the hypothesis that slow-moving purple sea urchins...

Research in a variety of vertebrate taxa has found that cardiac function is a major limiting factor in the ability of animals to cope with physiological challenges, and thus is suggested to play an important role in mediating fitness-related behaviors in the wild. Yet, there remains a paucity of empirical assessments of the relationships between ph...

In the 12 years since Dudgeon et al. (2006) reviewed major pressures on freshwater ecosystems, the biodiversity crisis in the world's lakes, reservoirs, rivers, streams and wetlands has deepened. While lakes, reservoirs and rivers cover only 2.3% of the Earth's surface, these ecosystems host at least 9.5% of the Earth's described animal species. Fu...

We show that cardiac sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA) activity differs considerably among sockeye salmon (Oncorhynchus nerka) populations. Variability in SERCA activity was significantly correlated with elevation gain and temperature during migration, as well as maximum cardiac stroke volume. Furthermore, because SERCA activity was...

• Climate change poses a challenge to wild fishes, yet little is known about the behavioural use and metabolic consequences of thermally heterogeneous water encountered by wild salmon during their energetically demanding upstream spawning migration. • Temperature, body size and activity levels were modelled to predict energy depletion of salmon dur...

For anadromous Pacific salmonid (Oncorhynchus spp.) smolts, the physiological state of individuals can influence migration fate. This critical life stage is typically associated with poor survival and influences population productivity, highlighting the need to identify intrinsic factors associated with outmigration fate. To better understand and i...

A variety of electronic tag types are routinely applied to fish to better understand migration biology. However, tagging procedures have the potential to affect the postrelease behaviour and survival of tagged individuals. In this study, wild adult Sockeye Salmon Oncorhynchus nerka from the Harrison River, British Columbia, were radio-tagged by gas...

This chapter reviews the influence of environmental temperature on the cardiovascular system. Specifically, we examine how the cardiovascular system responds to both acute and chronic changes in temperature, and how these responses differ across fish species. Cardiovascular responses from the whole organ down to the molecular level are considered....

Cardiovascular responses of decapod crustaceans to environmental challenges have received extensive attention. However, nearly all of these studies have been restricted to lab-based experiments; here we describe a methodology that will enable measurement of heart rate (HR) in free-moving decapods in the field. Data storage tag heart rate and temper...

The stress axis in teleost fish attempts to maintain internal homeostasis in the face of allostatic loading. However, stress axis induction has been associated with a higher predation rate in fish. To date, the physiological and behavioural factors associated with this outcome are poorly understood. The purpose of the present study was to investiga...

Selective harvest policies have been implemented in North America to enhance the conservation of Pacific salmon (Oncorhynchus spp.) stocks, which has led to an increase in the capture and release of fish by all fishing sectors. Despite the immediate survival benefits, catch-and-release results in capture stress, particularly at high water temperatu...

For migratory species, spatiotemporal variability in movement patterns, such as routes, has the potential to influence survival, but this aspect of movement ecology is poorly understood. For anadromous steelhead Oncorhynchus mykiss smolts, little is known about important migratory corridors used during early marine migration. To investigate route-s...

Synopsis: Wild animals maximize fitness through certain behaviors (e.g., foraging, mating, predator avoidance) that incur metabolic costs and often require high levels of locomotor activity. Consequently, the ability of animals to achieve high fitness often relies on their physiological capacity for exercise (aerobic scope) and/or their ability to...

The number of fish that encounter fishing gear is greater than the number of fish retained as catch. The proportion of this difference that die from the encounter is defined as fishing-related incidental mortality (FRIM). FRIM estimates are required for improved stock assessments, but they are difficult to attain and vary across fisheries. To cope...

Pacific salmon encounter widely varying environmental conditions across populations. Performance traits and environmental tolerance limits are predicted to be related to the typical abiotic and biotic conditions encountered by each population. Endurance swim performance at three different temperatures (8, 12, 22 °C) was compared across nine populat...

The hypothalamic-pituitary-interrenal (HPI) axis, through corticosteroid secretion, is an integral mechanism regulating internal homeostasis when vertebrates are faced with a stressor. However, continued HPI-axis stimulation can produce homeostatic overload, where corticosteroids are detrimental to organismal function. This overload condition may p...

Relating fish physiology, behaviour and experience to fitness-related outcomes at the individual scale is ecologically significant, but presents difficulties for free-ranging fishes in natural systems. Physiological state (e.g. level of stress or maturity) and experience (e.g. habitat use or exposure to stressors) may alter the probability of survi...

Growth hormone (GH) transgenic fish have been proposed for use in aquaculture to enhance production efficiency. As part of a risk analysis for use of such fish, the influence of GH transgenesis on the potential to persist and succeed in natural ecosystems is being examined in confined laboratory conditions. GH transgenesis can greatly accelerate gr...

Over the past decade nearly all of the research on the effects of climate change on fish has focused on the effects of warmer water temperatures. Yet, it is expected that temperature variability will also increase, resulting in more frequent incidences of rapid decreases in water temperatures (i.e. cold shock). Cold shock events have caused large-s...

Global climate change is altering freshwater ecosystems and affecting fish populations and communities. Underpinning changes in fish distribution and assemblage-level responses to climate change are individual-level physiological constraints. In this review, we synthesize the mechanistic effects of climate change on neuroendocrine, cardiorespirator...

Over the past several decades, a substantial amount of research has examined how cardiorespiratory physiology supports the diverse activities performed throughout the life cycle of Pacific salmon, genus Oncorhynchus. Pioneering experiments emphasized the importance of aerobic scope in setting the functional thermal tolerance for activity in fishes....

Acute stressors are commonly experienced by wild animals but their effects on fitness rarely are studied in the natural environment. Billions of fish are captured and released annually around the globe across all fishing sectors (e.g., recreational, commercial, subsistence). Whatever the motivation, release often occurs under the assumption of post...

Canadian freshwater fisheries provide vital economic, social, and cultural value. Maintaining the viability and sustainability of freshwater fisheries lies at the heart of the intersection between fisheries science, management, and policy. Even so, Canadian freshwater fisheries have been fraught with challenges since their earliest days. Fisheries...

While it is well known that O2 is directly removed from the water by skin and gill tissues of fish, the mismatch between O2 removal from water (O2 uptake; [Formula: see text]) and the O2 delivered to tissues by the primary circulation (O2 consumption; [Formula: see text]) has never been measured directly. Using data from four recent studies that si...

The main findings of the current study were that exposing adult sockeye salmon Onchorhynchus nerka to a warm temperature that they regularly encounter during their river migration induced a heat shock response at an mRNA level, and this response was exacerbated with forced swimming. Similar to the heat shock response, increased immune defence-relat...

Migrating adult sockeye salmon frequently encounter commercial and recreational fishing gear, from which they may be landed, escape or be intentionally released. In this experiment, migratory adult sockeye salmon were exposed to simulated capture–release in fresh water, including 3 min of exhaustive exercise and 60 s of air exposure at three ecolog...

This study showed that a coastal population (Harrison) of Fraser River sockeye salmon Oncorhynchus nerka had a lower aerobic and cardiac scope compared with interior populations with more challenging upriver spawning migrations, providing additional support to the idea that Fraser River O. nerka populations have adapted physiologically to their loc...

Elevated summer river temperatures are associated with high in-river mortality in adult sockeye salmon (Oncorhynchus nerka) during their once-in-a-lifetime spawning migration up the Fraser River (British Columbia, Canada). However, the mechanisms underlying the decrease in whole-animal performance and cardiorespiratory collapse above optimal temper...

Elevated river water temperature in the Fraser River, British Columbia, Canada, has been associated with enhanced mortality of adult sockeye salmon (Oncorhynchus nerka) during their upriver migration to spawning grounds. We undertook a study to assess the effects of elevated water temperatures on the gill transcriptome and blood plasma variables in...

Table S1. Functional analysis performed using the receiver operator characteristic (ROC) scoring method in ErmineJ for the first three principal components (PC) of the principal component analysis performed on all experimental years. Table S2. Functional analysis performed using the receiver operator characteristic (ROC) scoring method in ErmineJ f...

Despite growing interest in conservation physiology, practical examples of how physiology has helped to understand or to solve conservation problems remain scarce. Over the past decade, an interdisciplinary research team has used a conservation physiology approach to address topical conservation concerns for Pacific salmon. Here, we review how nove...

Climate change induced increases in summer water temperature have been repeatedly associated with elevated mortality of adult Fraser River sockeye salmon (Oncorhynchus nerka) during their upriver spawning migration. There are over 100 genetically and geographically distinct populations within the Fraser River watershed which encounter different mig...

Climate change-induced increases in summer water temperature have been associated with elevated mortality of adult sockeye salmon (Oncorhynchus nerka) during river migration. We show that cardiorespiratory physiology varies at the population level among Fraser River sockeye salmon and relates to historical environmental conditions encountered while...

![Figure][1] When the sardine fishery in the northern Benguela upwelling system, located off the southwest coast of Africa, collapsed because of over fishing in the 1960s the local ecosystem shifted dramatically to one dominated by jellyfish and the bearded goby. Surviving in the hypoxic and

![Figure][1] It is well established that bird lungs move air in a one-way loop through their gas-exchanging tubes during inhalation and exhalation. In contrast, mammals and presumably all other vertebrates breathe tidally, bringing air into the dead-end gas-exchange structures and back out

![Figure][1] The vertebrate lymphatic system is a network of vessels that collects excess fluid from tissues, delivers the fluid to lymph nodes and then ultimately returns the fluid back to the circulatory system for redistribution. The system plays a critical role in the immune response,

![Figure][1] There is widespread evidence that egg size has evolved through offspring and maternal fitness demands. Larger eggs typically bestow more nutrients, a larger birth weight and increased chance of survival on the offspring. Egg size is balanced with egg number to maximize maternal

![Figure][1] In cells, oxygen, small metabolites and macromolecules move around by molecular diffusion. Small cells have shorter diffusion distances than large cells, so the molecules are able to reach their destination more quickly. It is especially important that these various molecules

This review examines selected areas of cardiovascular physiology where there have been impressive gains of knowledge and indicates fertile areas for future research. Because arterial blood is usually fully saturated with oxygen, increasing cardiac output is the only means for transferring substantially more oxygen to tissues. Consequently, any beha...

Abstract For the first time, pre- and post-hepatic plasma lipid profiles were monitored following a single meal in a free-swimming, non-anaesthetized fish. Rainbow trout (Oncorhynchus mykiss; 700–1500 g; 10 °C) were equipped with cannulae in the dorsal aorta (DA) and hepatic portal vein (HPV). Simultaneous blood samples, taken from both cannulae at...

The mechanism underlying the decrease in aerobic scope in fish at warm temperatures is not fully understood and is the focus of this research. Our study examined oxygen uptake and delivery in resting, swimming and recovering sockeye salmon while water temperature was acutely increased from 15 degrees C to 24 degrees C in 2 degrees C h(-1) increment...

The HemoCue haemoglobin analyser consistently overestimated haemoglobin concentration ([Hb]) in the blood of all fish species (sockeye salmon Oncorhynchus nerka, Chinook salmon Oncorhynchus tshawytscha, Pacific bluefin tuna Thunnus orientalis and chub mackerel Scomber japonicus) by 22–50% (9·9–36·0 g l−1) over a [Hb] range of 20–160 g l−1. The syst...