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At least 73 records · Page 4

Multidrug Core–Shell Bead: A System for Bacterial Infection Treatment in Fish

This study was developed to improve the durability and bioavailability of polymer matrix containing the antibacterial agent’s bacitracin (BAC), berberine (BER) and sodium nitroprusside (SNP), an ionotropic gelation method was successfully applied to prepare alginate/chitosan core–shell beads. The structure and properties of different core–shell beads were characterized by scanning electron microscopy (SEM), zeta potential, Fourier transform infrared spectroscopy (FTIR), thermal analysis (DSC), swelling tests, bioadhesive assay, release kinetic profile and antibacterial/antibacteriostatic activity in bacterial model. The morphology of beads was investigated by SEM, display relatively spherical shape and revealed rough surface was also observed the appearance of cracks probably caused by partial collapsing of the polymer network during drying. The diameter means particle size observed was around 1.04 ± 0.13 mm, the particles showed a neutral value, around + 0.305 mV. Using UV–Vis technique was observed a high entrapment efficiency of compounds BAC, BER and SNP (> 95%) in the alginate/chitosan core–shell beads. As demonstrated, there is increase in the swelling degree in pH 6.2. The drug release profile showed a pH-dependent release kinetics. At pH 5.0 the most suitable kinetic model is Higuchi, at pH 6.2 a zero-order model is observed, while at pH 7.4 the Korsmeyer–Peppas model present a good fit. The presence of compounds on beads was confirmed using FTIR analyses, and the results indicated that there is no interaction between drugs and vehicle used in the formulation. We can consider after DSC analysis that beads containing BAC, BER and SNP are thermally more stable than separate formulations having the characteristics required for application at room temperature. The release system produced has physical characteristics that allow the storage of the drugs for long periods of time maintaining their chemical and pharmacological properties unchanged. The percentage of adhesion displayed value of 66%, that indicates the improvement in adherence time on the absorbing surfaces to improves drug bioavailability and effectiveness of compounds. In this study is displayed the additive effect between BAC, BER and SNP shown the potential application of compound combinations as an efficient, novel therapeutic tool for antibiotic-resistant bacterial infections. These results indicate that the proposed strategy improves drug bioavailability and effectiveness of compounds in the treatment of fish.

36 MATERIALS SCIENCE↗

2020 State of the Science Report, Chapter 3: Collision Risk for Animals around Turbines

The potential for marine animals to encounter and collide with turbines, especially tidal and river turbines, along with the biological, ecological, and regulatory consequences of any such interactions, remain active areas of research and topics of global interest. Uncertainty and knowledge gaps associated with collision risk continue to present challenges within consenting/permitting (hereafter consenting) processes for turbine developments. Consequently, collision risk continues to be the focus of significant research effort, which in recent years has included environmental monitoring of operational devices and arrays. This chapter addresses the overall progress and growth in knowledge across this topic area, and specific progress related to marine mammals, fish, and seabirds. https://tethys.pnnl.gov/publications/state-of-the-science-2020-chapter-3-collision

13 HYDRO ENERGY↗

Crumpling of silver nanowires by endolysosomes strongly reduces toxicity

Fibrous particles interact with cells and organisms in complex ways that can lead to cellular dysfunction, cell death, inflammation, and disease. The development of conductive transparent networks (CTNs) composed of metallic silver nanowires (AgNWs) for flexible touchscreen displays raises new possibilities for the intimate contact between novel fibers and human skin. Here, we report that a material property, nanowire-bending stiffness that is a function of diameter, controls the cytotoxicity of AgNWs to nonimmune cells from humans, mice, and fish without deterioration of critical CTN performance parameters: electrical conductivity and optical transparency. Both 30- and 90-nm-diameter AgNWs are readily internalized by cells, but thinner NWs are mechanically crumpled by the forces imposed during or after endocytosis, while thicker nanowires puncture the enclosing membrane and release silver ions and lysosomal contents to the cytoplasm, thereby initiating oxidative stress. This finding extends the fiber pathology paradigm and will enable the manufacture of safer products incorporating AgNWs.

60 APPLIED LIFE SCIENCES↗

Bats and Wind Turbines: Adding Ecological Context to the Olfaction Hypothesis

Several hypotheses attempt to explain why bats collide with wind turbines. One recent hypothesis is that collisions result from bats scent marking turbines and that scent-marked turbines produce odor plumes that attract bats. This olfaction hypothesis is intriguing, but currently lacks the ecological context required to assess its plausibility. To provide context, we review when we expect Northern Hoary Bats and Mexican Free-tailed Bats to scent mark under natural conditions, and determine if our findings align with observations of bats interacting with wind turbines. We then consider the plausibility of scent-marked turbines creating odor plumes that attract bats. We conclude that it is unlikely that bats scent mark turbines intentionally in mid-flight or are attracted to scent markings on turbines.

17 WIND ENERGY↗

Plasticity of Behavioral and Growth Responses to Two Feeding Regimes and Implications for the Domestication of Steelhead Trout

Abstract The effects of domestication selection on fitness are of serious concern in hatchery-reared anadromous salmonids, which often experience selection for rapid growth and associated deviations from natural agonistic and feeding behaviors. The high rations that are used to raise age-1 smolts and the reduced rations that are used to produce age-2 smolts potentially result in very different behavioral tactics and social dynamics of competition in hatchery tanks. Consequently, steelhead Oncorhynchus mykiss hatchery programs with recovery or conservation goals may need to change their aquaculture practices to minimize domestication selection. This study investigated how the feeding rate (proportion of presented food items that were successfully captured) and relative competitive ability (ability to monopolize food items in small groups) of age-1 and age-2 steelhead corresponded to feeding location (surface or bottom) and growth rate in hatchery rearing tanks. We raised steelhead from a common broodstock to smolt at age 1 or age 2 by manipulating their rations (age-1 fish received the high ration, age-2 the low ration). The fish in the age-1 treatment had a lower feeding rate than did those in the age-2 treatment. Feeding rate was positively correlated with both body size and with growth rate in the rearing tanks at both rations. The age-2 steelhead were more likely to be detected at a single feeding location than were the age-1 fish, which were more frequently detected at both locations. The more competitive age-1 fish were more frequently detected at both feeding locations, and the less competitive fish were detected at only one location. Relative competitive ability was not associated with feeding location in the age-2 treatment, nor was it associated with growth rate in either treatment. Age-2 steelhead that were detected only at the bottom or at both feeding locations had higher growth rates than those that were detected only at the surface, suggesting greater scramble competition near the point of food delivery under the restricted ration. Feeding location was not associated with growth rate in the age-1 treatment. The results indicate that ration directly affects feeding rate and that ration and relative competitive ability interact to influence feeding rate. Because feeding rate was positively associated with growth rate at both ration levels in the hatchery tanks, behaviors that are associated with feeding motivation may be an important trait under selection in salmonid hatcheries.

Tatara, Christopher P.↗

Temperature-dependent oxygen isotope fractionation in otoliths of juvenile Chinook salmon ( Oncorhynchus tshawytscha )

Oxygen thermometry has become a widely used technique for reconstructing thermal history in calcifying organisms but interpretation can be subject to predictive error from vital effects. To better understand these processes in Chinook salmon (Oncorhynchus tshawytscha) we experimentally constructed a temperature-dependent, otolith–water fractionation relationship for oxygen isotopes (δ 18 O) by rearing post-yolk absorptive juvenile fish at nominal temperatures from 6 to 21 °C. Temperature and otolith precipitation rate had significant effects on the otolith–water δ 18 O fractionation, but somatic growth rate did not. The slope of the δ 18 O fractionation equation also differed significantly from that of synthetic aragonite. Furthermore, our results suggest the expression of kinetic effects on δ 18 O fractionation in otoliths of Chinook salmon that are increasingly constrained at higher temperatures by other physical and physiological processes involved in mineral formation. Species-specific δ 18 O fractionation equations have considerable utility to reconstruct temperature history in Pacific salmon, but applications should recognize the potential for inferential uncertainty arising from interacting vital effects.

59 BASIC BIOLOGICAL SCIENCES↗

Differential DNA methylation and metabolite profiling of Atlantic killifish (Fundulus heteroclitus) from the New Bedford Harbor Superfund site

Atlantic killifish (Fundulus heteroclitus) is a valuable model in evolutionary toxicology to study how the interactions between genetic and environmental factors serve the adaptive ability of organisms to resist chemical pollution. Killifish populations inhabiting environmental toxicant-contaminated New Bedford Harbor (NBH) show phenotypes tolerant to polychlorinated biphenyls (PCBs) and differences at the transcriptional and genomic levels. However, limited research has explored epigenetic alterations and metabolic effects in NBH killifish. To identify the involvement of epigenetic and metabolic regulation in the adaptive response of killifish, we investigated tissue- and sex-specific differences in global DNA methylation and metabolomic profiles of NBH killifish populations, compared to sensitive populations from a non-polluted site, Scorton Creek (SC). The results revealed that liver-specific global DNA hypomethylation and differential metabolites were evident in fish from NBH compared with those from SC. The sex-specific differences were not greater than the tissue-specific differences. We demonstrated liver-specific enriched metabolic pathways (e.g., amino acid metabolic pathways converged into the urea cycle and glutathione metabolism), suggesting possible crosstalk between differential metabolites and DNA hypomethylation in the livers of NBH killifish. Additional investigation of methylated gene regions is necessary to understand the functional role of DNA hypomethylation in the regulation of enzyme-encoding genes associated with metabolic processes and physiological changes in NBH populations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Review: knots and other new topological effects in liquid crystals and colloids

Abstract Humankind has been obsessed with knots in religion, culture and daily life for millennia, while physicists like Gauss, Kelvin and Maxwell already involved them in models centuries ago. Nowadays, colloidal particles can be fabricated to have shapes of knots and links with arbitrary complexity. In liquid crystals, closed loops of singular vortex lines can be knotted by using colloidal particles and laser tweezers, as well as by confining nematic fluids into micrometer-sized droplets with complex topology. Knotted and linked colloidal particles induce knots and links of singular defects, which can be interlinked (or not) with colloidal particle knots, revealing the diversity of interactions between topologies of knotted fields and topologically nontrivial surfaces of colloidal objects. Even more diverse knotted structures emerge in nonsingular molecular alignment and magnetization fields in liquid crystals and colloidal ferromagnets. The topological solitons include hopfions, skyrmions, heliknotons, torons and other spatially localized continuous structures, which are classified based on homotopy theory, characterized by integer-valued topological invariants and often contain knotted or linked preimages, nonsingular regions of space corresponding to single points of the order parameter space. A zoo of topological solitons in liquid crystals, colloids and ferromagnets promises new breeds of information displays and a plethora of data storage, electro-optic and photonic applications. Their particle-like collective dynamics echoes coherent motions in active matter, ranging from crowds of people to schools of fish. This review discusses the state of the art in the field, as well as highlights recent developments and open questions in physics of knotted soft matter. We systematically overview knotted field configurations, the allowed transformations between them, their physical stability and how one can use one form of knotted fields to model, create and imprint other forms. The large variety of symmetries accessible to liquid crystals and colloids offer insights into stability, transformation and emergent dynamics of fully nonsingular and singular knotted fields of fundamental and applied importance. The common thread of this review is the ability to experimentally visualize these knots in real space. The review concludes with a discussion of how the studies of knots in liquid crystals and colloids can offer insights into topologically related structures in other branches of physics, with answers to many open questions, as well as how these experimentally observable knots hold a strong potential for providing new inspirations to the mathematical knot theory.

Physics↗

Colloidal structure and proton conductivity of the gel within the electrosensory organs of cartilaginous fishes

Cartilaginous fishes possess gel-filled tubular sensory organs called Ampullae of Lorenzini (AoL) that are used to detect electric fields. Although recent studies have identified various components of AoL gel, it has remained unclear how the molecules are structurally arranged and how their structure influences the function of the organs. Here we describe the structure of AoL gel by microscopy and small-angle X-ray scattering and infer that the material is colloidal in nature. To assess the relative function of the gel’s protein constituents, we compared the microscopic structure, X-ray scattering, and proton conductivity properties of the gel before and after enzymatic digestion with a protease. We discovered that while proteins were largely responsible for conferring the viscous nature of the gel, their removal did not diminish proton conductivity. The findings lay the groundwork for more detailed studies into the specific interactions of molecules inside AoL gel at the nanoscale.

59 BASIC BIOLOGICAL SCIENCES↗

International assessment of priority environmental issues for land-based and offshore wind energy development

Non-technical summary A substantial increase in wind energy deployment worldwide is required to help achieve international targets for decreasing global carbon emissions and limiting the impacts of climate change. In response to global concerns regarding the environmental effects of wind energy, the International Energy Agency Wind Technical Collaborative Program initiated Task 34 – Working Together to Resolve Environmental Effects of Wind Energy or WREN. As part of WREN, this study performed an international assessment with the global wind energy and environmental community to determine priority environmental issues over the next 5‒10 years and help support collaborative interactions among researchers, developers, regulators, and stakeholders. Technical summary A systematic assessment was performed using feedback from the international community to identify priority environmental issues for land-based and offshore wind energy development. Given the global nature of wind energy development, feedback was of interest from all countries where such development is underway or planned to help meet United Nations Intergovernmental Panel on Climate Change targets. The assessment prioritized environmental issues over the next 5–10 years associated with wind energy development and received a total of 294 responses from 28 countries. For land-based wind, the highest-ranked issues included turbine collision risk for volant species (birds and bats), cumulative effects on species and ecosystems, and indirect effects such as avoidance and displacement. For offshore wind, the highest-ranked issues included cumulative effects, turbine collision risk, underwater noise (e.g. marine mammals and fish), and displacement. Emerging considerations for these priorities include potential application to future technologies (e.g. larger turbines and floating turbines), new stressors and species in frontier regions, and cumulative effects for multiple projects at a regional scale. For both land-based and offshore wind, effectiveness of minimization measures (e.g. detection and deterrence technologies) and costs for monitoring, minimization, and mitigation were identified as overarching challenges. Social media summary Turbine collisions and cumulative effects among the international environmental priorities for wind energy development.

17 WIND ENERGY↗

Expansion of smallmouth bass distribution and habitat overlap with juvenile Chinook salmon in the Willamette River, Oregon

Abstract Smallmouth bass populations have expanded far beyond their native range and these predatory fish present a pervasive threat to native aquatic species throughout North America. In the western United States, smallmouth bass are now present in river and reservoir habitats where Pacific salmon are found and are considered a potential threat to salmon recovery in many locations. We conducted a study to determine if smallmouth bass are expanding their range in the mainstem Willamette River, Oregon, and developed a model to assess habitat overlap between smallmouth bass and juvenile Chinook salmon. Sampling during 2011–2022 revealed that the distribution of smallmouth bass had expanded throughout that timeframe to encompass the entire mainstem Willamette River, including important rearing habitats for juvenile Chinook salmon. The model predicted that smallmouth bass and juvenile Chinook salmon habitat overlap was substantial, highlighting the need for additional research to evaluate for potential negative impacts to salmon recovery in the basin. The model was also used to evaluate the efficacy of using flow management to reduce interactions between these two species, but the scenarios we examined suggested that this was not a viable option. These results highlight the need for continued research to assess interactions between smallmouth bass and juvenile salmon, and other native species of concern, in the Willamette River Basin. The development of the model is useful for resource managers to understand interactions between these species to prioritize locations for sampling in the future.

White, James S.↗

Cecropin P1 antimicrobial peptide modulates differential expression of immune relevant genes in rainbow trout ( Oncorhynchus mykiss ) gill cell line, RTgill-W1

Accumulated evidence indicates that antimicrobial peptides modulate immune activities in fish. In this study, we profiled the differential expression patterns of representative immune relevant genes in an epithelial-like cell line of rainbow trout gill, RTgill-W1, in response to exposure of cecropin P1 antimicrobial peptide. RTgill-W1 cells were treated with synthetic cecropin P1 over time (0, 2, 4 and 24 h) with or without the present of lipopolysaccharide (LPS) or polyinosinic polycytidylic acid (PolyI:C). The relative abundances of each mRNA were measured by real-time quantitative PCR. The dose-response study revealed significant perturbations of mRNA levels of genes related to pro-inflammation, acute phase, surface proteins and transcription factors at 30 μM of cecropin P1. In addition, cecropin P1 altered the differential expression patterns that were induced by LPS or PolyI:C, at different time points in RTgill-W1. Overall, our results indicate that cecropin P1 exhibits pro-inflammation activity, modulate cell-cell interaction and cytokine signal transduction in rainbow trout gill cell, and may suggest a potential application of this peptide as an immune adjuvant for disease control in aquaculture.

59 BASIC BIOLOGICAL SCIENCES↗

The little skate genome and the evolutionary emergence of wing-like fins

Skates are cartilaginous fish whose body plan features enlarged wing-like pectoral fins, enabling them to thrive in benthic environments. However, the molecular underpinnings of this unique trait remain unclear. Here we investigate the origin of this phenotypic innovation by developing the little skate Leucoraja erinacea as a genomically enabled model. Analysis of a high-quality chromosome-scale genome sequence for the little skate shows that it preserves many ancestral jawed vertebrate features compared with other sequenced genomes, including numerous ancient microchromosomes. Combining genome comparisons with extensive regulatory datasets in developing fins—including gene expression, chromatin occupancy and three-dimensional conformation—we find skate-specific genomic rearrangements that alter the three-dimensional regulatory landscape of genes that are involved in the planar cell polarity pathway. Functional inhibition of planar cell polarity signalling resulted in a reduction in anterior fin size, confirming that this pathway is a major contributor to batoid fin morphology. We also identified a fin-specific enhancer that interacts with several hoxa genes, consistent with the redeployment of hox gene expression in anterior pectoral fins, and confirmed its potential to activate transcription in the anterior fin using zebrafish reporter assays. Our findings underscore the central role of genome reorganization and regulatory variation in the evolution of phenotypes, shedding light on the molecular origin of an enigmatic trait.

59 BASIC BIOLOGICAL SCIENCES↗

Mixture Effects of Per- and Polyfluoroalkyl Substances on Embryonic and Larval Sheepshead Minnows ( Cyprinodon variegatus )

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous and persistent environmental contaminants originating from many everyday products. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are two PFAS that are commonly found at high concentrations in aquatic environments. Both chemicals have previously been shown to be toxic to fish, as well as having complex and largely uncharacterized mixture effects. However, limited information is available on marine and estuarine species. In this study, embryonic and larval sheepshead minnows (Cyprinodon variegatus) were exposed to several PFAS mixtures to assess lethal and sublethal effects. PFOS alone was acutely toxic to larvae, with a 96 h LC50 of 1.97 mg/L (1.64–2.16). PFOS + PFOA resulted in a larval LC 50 of 3.10 (2.62–3.79) mg/L, suggesting an antagonistic effect. These observations were supported by significant reductions in malondialdehyde (105% ± 3.25) and increases in reduced glutathione concentrations (43.8% ± 1.78) in PFOS + PFOA exposures compared to PFOS-only treatments, indicating reduced oxidative stress. While PFOA reduced PFOS-induced mortality (97.0% ± 3.03), perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA) did not. PFOS alone did not affect expression of peroxisome proliferator-activated receptor alpha (pparα) but significantly upregulated apolipoprotein A4 (apoa4) (112.4% ± 17.8), a downstream product of pparα, while none of the other individually tested PFAS affected apoa4 expression. These findings suggest that there are antagonistic interactions between PFOA and PFOS that may reduce mixture toxicity in larval sheepshead minnows through reduced oxidative stress. Elucidating mechanisms of toxicity and interactions between PFAS will aid environmental regulation and management of these ubiquitous pollutants.

59 BASIC BIOLOGICAL SCIENCES↗

Pollinator habitat in solar facilities has potential to support high diversity of bee species

Conversion of agricultural and degraded lands to solar energy production provides opportunities to support diverse bee communities—and their pollination services—by creating habitat at solar facilities. Habitat restoration for bees at solar facilities follows the general principle of installing a diverse flowering plant community and assuming bees will come. However, selecting seed mixes for solar facilities is challenging because selected plants need to establish in the unique abiotic conditions of solar facilities and not interfere with solar energy production (tall plants may shade panels). Recent research tested commercially available and bespoke pollinator mixes for establishment success in Minnesota solar facilities and identified 14 forb species that established successfully over three years of the experiment. We ask an important follow-up question: how many native bee species, and which bee species, are these 14 plant species capable of supporting? We used a plant-bee interaction data set from Minnesota to calculate the number of bee species that would be supported by the 14 plant species for the duration of their flight seasons using a published bee species richness function. We found 122 unique bee species (24% of Minnesota diversity) may be supported for their entire flight seasons by the 14 focal plants.

14 SOLAR ENERGY↗

PyZebrascope: An Open-Source Platform for Brain-Wide Neural Activity Imaging in Zebrafish

Understanding how neurons interact across the brain to control animal behaviors is one of the central goals in neuroscience. Recent developments in fluorescent microscopy and genetically-encoded calcium indicators led to the establishment of whole-brain imaging methods in zebrafish, which record neural activity across a brain-wide volume with single-cell resolution. Pioneering studies of whole-brain imaging used custom light-sheet microscopes, and their operation relied on commercially developed and maintained software not available globally. Hence it has been challenging to disseminate and develop the technology in the research community. Here, we present PyZebrascope, an open-source Python platform designed for neural activity imaging in zebrafish using light-sheet microscopy. PyZebrascope has intuitive user interfaces and supports essential features for whole-brain imaging, such as two orthogonal excitation beams and eye damage prevention. Its camera module can handle image data throughput of up to 800 MB/s from camera acquisition to file writing while maintaining stable CPU and memory usage. Its modular architecture allows the inclusion of advanced algorithms for microscope control and image processing. As a proof of concept, we implemented a novel automatic algorithm for maximizing the image resolution in the brain by precisely aligning the excitation beams to the image focal plane. PyZebrascope enables whole-brain neural activity imaging in fish behaving in a virtual reality environment. Thus, PyZebrascope will help disseminate and develop light-sheet microscopy techniques in the neuroscience community and advance our understanding of whole-brain neural dynamics during animal behaviors.

59 BASIC BIOLOGICAL SCIENCES↗

Renewable energy and biological conservation in a changing world

Without a shift to renewable energy sources, climate change will have adverse effects on many terrestrial and aquatic species. On the other hand, replacing fossil fuels with renewable energy will have different effects on wildlife, some negative. To protect biota, while navigating the complexities surrounding the transition to renewable energy, will require sharing knowledge between energy experts and wildlife experts, as well as policy makers and resource managers. This special issue is intended to advance the conversation. Interactions between renewable energy facilities and fauna are complex. Each source of renewable energy has its own conservation concerns, and each presents its own set of opportunities for mitigation; Other concerns and mitigations are shared. In this overview, we review climate risks to biota, clarify the complementarities among renewables for the conservation community, and summarize research on energy effects on biota for the energy community. The papers invited for this special issue address fossil (coal, oil, natural gas) and renewable energy (terrestrial biomass energy, hydropower, marine-hydrokinetic energy, wind energy, solar energy) and affected fauna. Finally, we hope that the results of these studies, and others like them, set us on a path toward low-carbon energy systems that provide society with energy while protecting future biodiversity.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Water Temperature, Prey Concentration and Salmonid Density Influence Daily Growth of Wild Juvenile Salmonids in Tributaries of the Upper Salmon River, Idaho ( USA )

ABSTRACT Theory, experiments and field studies indicate that the somatic growth rate of freshwater consumers is shaped by the individual, additive and multiplicative effects of multiple factors, including consumer size and condition, temperature, prey resources and biotic interactions. While our understanding of how these factors affect wild populations of freshwater consumers is improving, the topic remains poorly studied, especially with respect to mobile species. Here, we report on an 8‐year, seven‐stream ( n = 49 stream‐year combinations) observational study examining the individual and interactive effects of invertebrate prey concentration (F, mg/m 3 ), mean daily water temperature (T, °C) and juvenile Chinook salmon ( Oncorhynchus tshawytscha ) density (D, fish/100 m 2 ) on summer daily growth rates (%/d) of mobile, anadromous, juvenile Chinook salmon (age‐0+, n = 382) and sub‐yearling (age‐0+, n = 61) and yearling (age‐1+) steelhead trout ( O. mykiss , n = 70) rearing in cold (mean daily summer: 12.1°C, range: 4.2°C–16.7°C) mountain tributaries of the Salmon River basin in central Idaho (USA). AIC c model selection indicated that daily juvenile salmonid growth positively correlated with water temperature, prey biomass concentration, local juvenile Chinook density and the interaction between water temperature and food but with species and age‐specific differences. Water temperature was a covariate in all top‐ranked models, with daily growth (%/day) rate increasing (0.05%–0.23%/d) linearly with mean daily summer water temperature. In addition to a direct positive relationship with daily growth rate, there was evidence that prey concentration positively interacted with water temperature to accelerate daily growth (F × T). The positive relationship between juvenile salmonid daily growth rate and juvenile Chinook density is difficult to explain and could result from confounding factors. The individual success observed in these streams may contribute to population‐level benefits for the focal consumers, as prey‐rich, warm summers may result in larger individuals with higher energy reserves at the end of the summer/autumn growing season, contributing to improved overwinter survival. Our results, taken in combination with evidence from models, experiments and observational studies, have climate change implications. Current and predicted increases in water temperature will necessitate higher rates of prey consumption by aquatic ectothermic consumers to offset accelerated metabolic demands. Thus, to improve the resilience of mobile freshwater consumers in a warming climate, we suggest that natural resource managers not only consider physical and chemical habitat conditions but also biotic conditions, including the spatiotemporal quantity and quality of prey resources.

Kiffney, Peter. M. [Fish Ecology, Northwest Fisher↗