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The SNP variation in sockeye salmon across the Asian part of its range was studied in 23 samples from 16 lake–river systems of the West Pacific Coast to improve understanding of genetic adaptation in response to spawning watersheds conditions. Identification of candidate SNPs and environmental factors that can contribute to local adaptations in sockeye salmon populations was carried out using redundancy analysis (RDA), a powerful tool for landscape genetics proven to be effective in genotype–environment association studies. Climatic and hydrographic indices (7 indices in total), reflecting abiotic conditions in freshwater habitats of sockeye salmon and characterizing the temperature regime in the river basin, its variability during the year, the amount of precipitation, as well as the height of the maximum tide in the estuary, were used as predictor factors. Among the 45 analyzed SNPs, several loci (ALDOB-135, HGFA, and RAG3-93) correlated with predictors gradients along the northwest Pacific coast were identified. The putative candidate loci localized in genes involved in the immune and inflammatory responses, as well as genes encoding temperature-sensitive enzymes and some hormones regulating ion homeostasis in fish during the anadromous migration and smoltification, were potentially associated with environmental conditions in natal rivers. The findings could have implications for aquaculture, conservation, and resource management in the context of global climate change. [ABSTRACT FROM AUTHOR]

In order to describe large-scale spatial structure of sockeye salmon on the Asian part of the range, the variability of 45 SNP loci was analyzed in 22 samples from the Northwest coast of the Pacific Ocean. Three large regional population complexes were identified: Southwest Kamchatka, Kamchatka River basin, and the Northeast (comprising stocks from Koryak Highlands). Populations within the identified complexes are connected by gene migration and have a common origin, close geographic proximity, comparable climatic, landscape, and environmental conditions in the freshwater and early marine periods of sockeye salmon life. Populations confined to watersheds of the North coast of the Sea of Okhotsk (Palana and Okhota rivers), along with island populations, displayed distinctions from the isolated population complexes. It is hypothesized that the marked divergence observed in island populations is primarily caused by genetic drift occurring during long periods of isolation. The pronounced divergence of Palana River population may be the result of both genetic drift and natural selection, driven by the challenging smoltification and specific conditions of freshwater period in this watershed. At the same time in the Okhota River population, demographic factors such as genetic drift and bottlenecks played a key role. [ABSTRACT FROM AUTHOR]

The Fraser River once supported massive salmon returns. However, over the last century, the largest returns have consistently been less than half of the recorded historical maximum. There is substantial interest from surrounding communities and governments to increase salmon returns for both human use and functional ecosystems. To generate resources for this endeavor, we resequenced genomes of Chinook (Oncorhynchus tshawytscha), coho (Oncorhynchus kisutch), and sockeye salmon (Oncorhynchus nerka) from the Fraser River at moderate coverage (∼16×). A total of 954 resequenced genomes were analyzed, with 681 collected specifically for this study from tissues sampled between 1997 and 2021. An additional 273 were collected from previous studies. At the species level, Chinook salmon appeared to have 1.6–2.1× more SNPs than coho or sockeye salmon, respectively. This difference may be attributable to large historical declines of coho and sockeye salmon. At the population level, 3 Fraser River genetic groups were identified for each species using principal component and admixture analyses. These were consistent with previous research and supports the continued use of these groups in conservation and management efforts. Environmental factors and a migration barrier were identified as major factors influencing the boundaries of these genetic groups. Additionally, 20 potentially adaptive loci were identified among the genetic groups. This information may be valuable in new management and conservation efforts. Furthermore, the resequenced genomes are an important resource for contemporary genomics research on Fraser River salmon and have been made publicly available. [ABSTRACT FROM AUTHOR]

The Journal of Architectural Education features an interview with Brett Story, Emily Kassie, and Julian Brave NoiseCat, discussing their documentary filmmaking practices within the context of worlding. They explore colonial and capitalist violence through projects like Sugarcane and The Prison in Twelve Landscapes, delving into the politics and radical imaginaries these films evoke. The conversation touches on the importance of storytelling, the impact of residential schools and the prison-industrial complex on communities, and the need for truth-telling and reconciliation. The filmmakers highlight the significance of stewardship, self-determination, and the generational divide in addressing systemic issues and envisioning new worlds. [Extracted from the article]

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 compares the outmigration timing, size, and habitat use of juvenile Chinook salmon in the Fraser River estuary. Over 5 years (2016–2020), we captured 6493 juvenile Chinook salmon, with 3318 sampled for stock identification. Fraser River Chinook salmon extensively used estuary habitats, but patterns varied considerably by population. Juvenile Chinook salmon from the Lower Fraser River were most abundant and present the longest, arriving the smallest in late March and early April, and captured until July. South Thompson ocean-type Chinook salmon entered the estuary later, starting to arrive in late May or early June and remaining present until mid-August. Overall, juvenile Chinook salmon varied considerably in their estuary use across populations. Understanding this variation can inform differences in productivity and guide recovery actions. [ABSTRACT FROM AUTHOR]

The presence of dams on the Columbia River (CR) has reduced Sockeye Salmon (Oncorhynchus nerka|sćwin) numbers to a fraction of their historic numbers. The Syilx Okanagan Nation Alliance (SONA) has led voices of concern regarding the impacts of diminishing Sockeye Salmon numbers on the ecosystem health of the sq,awsitkʷ|Okanagan River (s|OR), a tributary of the CR. In the early 2000s efforts commenced to rehabilitate the s|OR Sockeye population. These efforts have seen the population rise from a running average of 40,000 to 200,000. However, the contemporary spawning capacity of the s|OR is unknown, and this metric is critical to guide the conservation and restoration of this keystone species. We employed a spawning capacity model relating fish length and gravel size to spawning potential. We collected substrate data at 49 sites throughout our 37‐km study area, and used fish length and egg numbers from n = 269 Sockeye Salmon to establish s|OR specific fecundity metrics. The model estimated the s|OR has the capacity to support 147,687 (±33,346) Sockeye spawners, in its current condition. Whilst our model has limitations, we suggest a minimum escapement of 147,687 Sockeye spawners ought to be passed to the s|OR per annum. These fish will have broad ecosystem benefits and will be culturally beneficial to SONA peoples. Finally, continued restoration of s|OR habitat should enhance opportunities for Sockeye Salmon to continue their remarkable recovery. [ABSTRACT FROM AUTHOR]

Feeding habits of salmon are examined on the data from “Trophology” and “Zooplankton” databases for 1988–2023, taking into account calendar dates and spatial localiza tion of the salmon size classes. The dominant zooplankton species and groups in salmon food are defined and their availability in terms of time and depth of habitat is determined. Daily rhythm of salmon feeding is found uniform for all size groups. The areas and time (months) of maximum concentrations of salmon are determined, by size groups, and those ones are considered as the areas and periods of their most active consumption. A trophological calendar is constructed to show where, when, and what type of food is consumed by certain species and size group of salmon. Daily food rations are calculated for all salmon species and size groups. The rations are similar with those in the Bering Sea, with small differences possibly caused by different structure of the plankton communities. The application tables are compiled for operational calculations of total food consumption by size groups of salmon species with a predominant zooplankton prey (pink, chum and sockeye). According to the forecast published at VNIRO website vniro.ru, the salmon catch in the Far Eastern basin will decrease by more than 2 times in 2024, primarily due to pink salmon. In this case, significant reduction in salmon pressure on plankton community can be expected.

The productivity of Pacific Sockeye salmon (Oncorhynchus nerka) in the Columbia River has been declining over the past century. Yet, the Okanagan River Sockeye salmon population, which spawns in the Okanagan River, a Canadian tributary of the Columbia River, has seen a remarkable turnaround in abundance. Different hypotheses and lines of evidence covering multiple spatial scales have been proposed to explain this recovery; but they have never been comprehensively assessed. We adopted a weight-of-evidence approach to systematically assess the relative likelihood that each of these causal hypotheses contributed to the observed recovery. Our analysis disentangles the relative consequences of a set of environmental management actions that have been implemented to augment the Sockeye salmon freshwater productivity, while accounting for changes in freshwater and marine environmental conditions. Our list of potentially explanatory causal factors (anthropogenic and natural) included: (1) changes in escapement concurrent with improving local fish passage, (2) the implementation of fish-friendly flows in the Okanagan River, (3) initiating a hatchery restocking program, (4) potential improvements to Columbia dam operations to support higher relative survival of out-migrating juvenile fish, (5) possible shifts in survival-favorable conditions in the coastal marine environment for ocean-going life stages, and (6) broader changes to multi-stock harvest regimes in the Columbia River. Our assessment leveraged comparisons with the population dynamics of another Sockeye salmon stock in the Columbia River basin to differentiate between the impacts of management actions taken within the Okanagan watershed (our focus) from those occurring over the broader basin and marine scale. The results suggest that while shifts towards survival-favorable conditions in the coastal marine environment in 2007 played an important role in the upturn of the Okanagan population, alone it cannot explain the rate at which the Okanagan River Sockeye salmon recovered. Strong evidence supports the combined effect of increased escapement in conjunction with establishing and securing fish-friendly flows during spawning, incubation, and alevin emergence. Additionally, Sockeye salmon restocking improved the resilience of the stock against density-independent mortality events. These combined basin-level management actions played a pivotal role in magnifying the recovery trajectory afforded by improved marine survivorship. The spectacular response of the Okanagan River Sockeye salmon to the holistic perspectives and management interventions of Indigenous and other caretakers provides hope that other Pacific salmon stocks can be stabilized and recovered. [ABSTRACT FROM AUTHOR]

Several stages are determined in the early run of sockeye salmon into tributaries of Lake Nachikinskoye: i) maturation of adults at depth, ii) concentration of adults in the mouths of the main tributaries, iii) entry of small flocks of the spawners into tributaries over a short distance, iv) upstream movement of lager flocks, v) thinning of flocks and formation of pairs, vi) spawning, and vii) death of spawned fish. In the large, stable accumulations formed in the mouths of tributaries, salmon choose paths for onward movement in the process of homing, by decoding imprinting information. There, aggregations of spawners are differentiated into separate flocks going to spawn on different spawning grounds. A peculiarity of this population of sockeye salmon is the retention of individuals not ready for spawning in many pits and catches of the rivers, with formation of well-visible compact schools, which dissipate as the fish mature. Filling of the spawning grounds in tributaries is determined by their characteristics, and typically occurs with a dome-shaped dynamics of intensity. The upward long-term trend in filling of the spawning grounds is observed in the lower Taburetka River (before its tributaries), while the downward trend — in the tributaries. Data on the filling for the last 5 years are presented. The greatest contribution to reproduction of the early sockeye salmon in Lake Nachikinskoye is provided by the lower reaches of the Taburetka River (41 %), whereas its tributary, the Verkhnyaya River, contributes 20 % and inputs of other tributaries are noticeably lower. In conditions of degradation for a part of the spawning grounds due to increased anthropogenic impact, all existing subpopulations should be preserved as productive as possible.

Family Parvoviridae consists of small, non-enveloped viruses with linear, single-stranded DNA genomes of approximately 4-6 kilobases, subdivided into three subfamilies, Parvovirinae, Densovirinae, and Hamaparvovirinae, and unassigned genus Metalloincertoparvovirus. Parvoviruses of aquatic animals infect crustaceans, mollusks, and finfish. This review describes these parvoviruses, which are highly host-specific and associated with mass morbidity and mortality in both farmed and wild aquatic animals. They include Cherax quadricarinatus densovirus (CqDV) in freshwater crayfish in Queensland, Australia; sea star-associated densovirus (SSaDV) in sunflower sea star on the Northeastern Pacific Coast; Clinch densovirus 1 in freshwater mussels in the Clinch River, Virginia, and Tennessee, USA, in subfamily Densovirinae; hepatopancreatic parvovirus (HPV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) in farmed shrimp worldwide; Syngnathid ichthamaparvovirus 1 in gulf pipefish in the Gulf of Mexico and parts of South America; tilapia parvovirus (TiPV) in farmed tilapia in China, Thailand, and India, in the subfamily Hamaparvovirinae; and Penaeus monodon metallodensovirus (PmMDV) in Vietnamese P. monodon, in unassigned genus Metalloincertoparvovirus. Also included in the family Parvoviridae are novel parvoviruses detected in both diseased and healthy animals using metagenomic sequencing, such as zander parvovirus from zander in Hungary and salmon parvovirus from sockeye salmon smolts in British Columbia, Canada. [ABSTRACT FROM AUTHOR]

Pacific salmon (Oncorhynchus spp.) hatch and feed in freshwater habitats, migrate to sea to mature, and return to spawn at natal sites. The final, riverine stages of the return migrations are mediated by chemical properties of the natal stream that they learned as juveniles. Like some other fish, salmon growth is asymptotic; they grow continuously throughout life toward a maximum size. The continued growth of the nervous system may be plastic in response to environmental variables. Due to the ecological, cultural, and economic importance of Pacific salmon, individuals are often reared in hatcheries and released into the wild as juveniles to supplement natural populations. However, hatchery-reared individuals display lower survivorship and may also stray (i.e. spawn in a non-natal stream) at higher rates than their wild counterparts. Hatchery environments may lack stimuli needed to promote normal development of the nervous system, thus leading to behavioral deficits and a higher incidence of straying. This study compared the peripheral olfactory system and brain organization of hatchery-reared and wild-origin sockeye salmon fry (Oncorhynchus nerka). Surface area of the olfactory rosette, diameter of the olfactory nerve, total brain size, and size of major brain regions were measured from histological sections and compared between wild and hatchery-origin individuals. Hatchery-origin fish had significantly larger optic tecta, and marginally insignificant, yet noteworthy trends, existed in the valvula cerebelli (hatchery > wild) and olfactory bulbs (hatchery < wild). We also found a putative difference in olfactory nerve diameter (d min) (hatchery > wild), but the validity of this finding needs further analyses with higher resolution methods. Overall, these results provide insight into the potential effects of hatchery rearing on nervous system development in salmonids, and may explain behavioral deficits displayed by hatchery-origin individuals post-release. [ABSTRACT FROM AUTHOR]

This article provides an overview of the current state of the Bering Sea, focusing on various factors such as climate patterns, sea surface temperatures, winter winds, sea ice patterns, and bottom temperatures. It also discusses the decline in the population of Bering Sea snow crab and the impact of a marine heatwave event. The article concludes with information about upcoming surveys and acknowledges the scientists involved in the research. The authors, Emily Lemagie and Elizabeth Siddon, are experts in their respective fields and provide valuable insights into the ecosystem of the Bering Sea. [Extracted from the article]

The Canadian Fraser River sockeye salmon (Oncorhynchus nerka) is one of the largest stock complexes in North America, supporting major commercial, recreational, and First Nations fisheries. Sockeye fisheries management relies on an annual pre-season forecast of adult returns. In this study, we developed a comprehensive framework for visualization with a Taylor diagram to evaluate pre-season forecast models annually and identify external drivers important for forecasting sockeye returns. Specifically, we incorporated five new covariates, including sea surface temperature in the Gulf of Alaska and the abundance of salmon species, into the existing forecast models. Results revealed better performances by both the Ricker and Power models when coupled with the newly included covariates. Moreover, models selected over a decade ago underperformed compared to those selected based on our recent retrospective analysis from 2009 to 2020. We advocate for continuous evaluation of forecast models in the face of environmental change, emphasizing the necessity of developing models that incorporate non-stationary processes and assess the impacts of environmental and ecological factors on Fraser sockeye dynamics. [ABSTRACT FROM AUTHOR]

Results of the trawl survey in the Pacific waters at Kuril Islands within and outside EEZ of Russia conducted by RV TINRO in June-July 2023 are analyzed. Data on spatial distribution, abundance and biomass of fish, cephalopod and jellyfish species in the epipelagic layer are presented. Contemporary status of the epipelagic nekton community in the surveyed area is analyzed. Quantitative distribution and biological state of pink salmon and other species of salmon in the summer season are considered in details.

Since 2017, volatility of weekly wholesale prices for pacific salmon increased in the Russian domestic market, particularly in the Far East of Russia, that had coincided with higher fluctuations of the weekly and annual catch. Correlation between these variables is investigated for the period from 2010 to 2022, using graphical and regression analyses and 18-factor model for prices of the pink, chum, and sockeye salmon products. The dynamics of prices for pacific salmon products cannot be fully explained only by catch dynamics, but depends on a number of supplementary factors affecting the activities of fish industry enterprises. Anyway, a degree of the catch and price in preceding weeks influence on the wholesale prices is estimated for the main species of pacific salmon. The impact of the catch factor is not significant though more considerable for pink salmon product prices than for the other pacific salmon species.

In response to ocean heating and hatchery production, pink salmon (Oncorhynchus gorbuscha) returning from the North Pacific Ocean steadily increased after 1975, leading to concerns about their influence on food webs and competition with other species. Using measurements of distance between scale annuli of 24 584 individual sockeye salmon (O. nerka), we examined growth during their 2 or 3 years at sea from 1977 to 2015 for eight populations in Alaska. We found significant, negative autocorrelations at 1 lag year in annual growth of sockeye salmon, with a consistent pattern of lower growth in odd years, i.e. opposite to the biennial pattern of pink salmon abundance. Peak pink salmon abundances reduced growth of sockeye salmon from 7 to 14% during the second year in the ocean compared with growth when pink salmon abundance was low, while third-year growth was reduced up to 17%. The overall effect of pink salmon abundance on sockeye growth was over two times greater than the effect of sockeye salmon abundance. Production hatcheries and ocean heating contribute to the competitive dominance of pink salmon, underscoring the need to consider this unintended anthropogenic effect on the growth and productivity of sockeye salmon throughout the North Pacific. [ABSTRACT FROM AUTHOR]

We analyzed handedness of brown bears (Ursus arctos), which is the tendency to differentially use the right or left forelimb for dexterous actions. Handedness in mammals is hypothesized to be an outcome of lateralization of neocortex function, which serves to increase cognitive capacity by reducing redundancy of function between left and right hemispheres. Handedness in brown bears would give insight into brown bear capacity for cognition and innovative behavior. We tallied brown bear forelimb use from videography of bears foraging on anadromous sockeye salmon (Oncorhynchus nerka) while aggregated at the Brooks River within Katmai National Park, Alaska, USA, during autumn 2022. Brown bears exhibited a significant propensity for handedness, a result driven primarily by brown bears using their right forelimb more often than their left to swat at conspecifics during social interactions. Under the model that neocortex lateralization increases cognitive capacity, the right-handedness we observed in brown bears is consistent with their capacity for problem solving and behavioral innovation. [ABSTRACT FROM AUTHOR]

Hydrolyzed collagen (HC) derived from salmon (Oncorhynchus nerka) skin possesses properties that can nourish the skin, and it is one of the active ingredients used in cosmeceutical products for moisturizing the facial skin. However, HC solution gives off a fishy odor and it is gray in color that makes the product unacceptable for cosmetic purposes. This study aimed to use liposome-encapsulated hydrolyzed salmon collagen to improve its physical appearance, skin permeation, and eliminate the fishy odor. Two percent of HC and vitamin B3 (VitB3) were used as active ingredients to incorporate into liposomes. Phosphatidylcholine, cholesterol, and Tween 80 at a suitable weight ratio of 8 : 2 : 1 produced nano-sized vesicles (170.6 ± 0.70 nm) with the highest percentage of entrapment efficiency (95.72 ± 2.00%) of VitB3 and (49.63 ± 1.74%) of HC. Skin permeation and odor detection of the HC-VitB3 liposome were studied using Franz's diffusion cell and gas chromatography, respectively, and compared with HC-VitB3 solution. Subsequently, facial serums were formulated using HC-VitB3 liposomes and HC-VitB3 solutions, and a product satisfaction test was conducted with 100 volunteers to determine their preferred product. The results of the studies of HC-VitB3 liposome serum showed improved formulation appearance, enhanced skin permeation, and better odor elimination compared to the HC-VitB3 serum. Furthermore, seventy-three volunteers in the product satisfaction test preferred and selected the liposomal serum for its superior scent. From all the experimental results, it could be seen that liposomes can help increase skin penetration, and undesirable odors and colors can be masked by the appropriate lipid bilayer structure of liposomes. [ABSTRACT FROM AUTHOR]

Climate change is altering the distribution and abundance of marine species, especially in Arctic and sub‐Arctic regions. In the eastern Bering Sea, home of the world's largest run of sockeye salmon (Oncorhynchus nerka), juvenile sockeye salmon abundance has increased and their migration path shifted north with warming, 2002–2018. The reasons for these changes are poorly understood. For these sockeye salmon, we quantify environmental and biological covariate effects within spatio‐temporal species distribution models. Spatio‐temporally, with respect to juvenile sockeye salmon densities: (1) sea surface temperature had a nonlinear effect, (2) large copepod, Calanus, a minor prey item, had no effect, (3) age‐0 pollock (Gadus chalcogrammus), a major prey item during warm years, had a positive linear effect, and (4) juvenile pink salmon (O. gorbuscha) had a positive linear effect. Temporally, annual biomass of juvenile sockeye salmon was nonlinearly related to sea temperature and positively related to age‐0 pollock and juvenile pink salmon abundance. Results indicate that sockeye salmon distributed with and increased in abundance with increases in prey, and reached a threshold for optimal temperatures in the eastern Bering Sea. Changes in population dynamics and distribution of sockeye salmon in response to environmental variability have potential implications for projecting specific future food securities and management of fisheries in Arctic waters. [ABSTRACT FROM AUTHOR]

How has parasitism changed for Alaskan salmon over the past several decades? Parasitological assessments of salmon are inconsistent across time, and though parasite data are sometimes noted when processing fillets for the market, those data are not retained for more than a few years. The landscape of parasite risk is changing for salmon, and long‐term data are needed to quantify this change. Parasitic nematodes of the family Anisakidae (anisakids) use salmonid fishes as intermediate or paratenic hosts in life cycles that terminate in marine mammal definitive hosts. Alaskan marine mammals have been protected since the 1970s, and as populations recover, the density of definitive hosts in this region has increased. To assess whether the anisakid burden has changed in salmonids over time, we used a novel data source: salmon that were caught, canned, and thermally processed for human consumption in Alaska, USA. We examined canned fillets of chum (Oncorhynchus keta, n = 42), coho (Oncorhynchus kisutch, n = 22), pink (Oncorhynchus gorbuscha, n = 62), and sockeye salmon (Oncorhynchus nerka, n = 52) processed between 1979 and 2019. We dissected each fillet and quantified the number of worms per gram of salmon tissue. Anisakid burden increased over time in chum and pink salmon, but there was no change in sockeye or coho salmon. This difference may be due to differences in the prey preferences of each species, or to differences in the parasite species detected across hosts. Canned fish serve as a window into the past, providing information that would otherwise be lost, including information on changes over time in the parasite burden of commercially, culturally, and ecologically important fish species. [ABSTRACT FROM AUTHOR]

Introducing anadromous fish upstream of migration barriers has frequently been proposed as a conservation strategy, but existing conditions and future changes to the ecosystems above barriers such as invasive species, climate change, and varying water operations influence the capacity to support such introductions. In the Upper Skagit River, Washington, USA, introduction of anadromous salmonids above three high-head dams was proposed; however, the proliferation of invasive redside shiner Richardsonius balteatus fundamentally altered reservoir food web interactions, presenting potential challenges for the growth and production of introduced anadromous salmonids. By combining empirical measurements of zooplankton availability and temporal patterns in thermal structure of the reservoir with bioenergetics model simulations to quantify the rearing capacity of Ross Lake, we estimated the lake could support millions of sockeye salmon fry entering in spring after accounting for temporal consumption demand by the existing planktivore community dominated by redside shiner. The initial fry estimates varied according to the expected fry-to-smolt survival rate, and whether salmonids would be thermally restricted from prey in the epilimnion. This translated to estimates of 189,000 to 285,000 smolts leaving the following spring, and 7700 to 11,700 returning adults, using mean fry-to-smolt and smolt-to-adult survival rates from a nearby sockeye salmon population. We also estimated that predation potential could pose substantial mortality for lake-rearing sockeye or Chinook salmon, although it is expected to play a lesser role in limiting survival of species that only migrate through the reservoir. These results provide a case study and framework for examining bottom-up and top-down food web processes that influence growth and survival of introduced anadromous salmonids in reservoir habitats, thus guiding the direction of future feasibility studies in Ross Lake and other regulated rivers where introduction programs are considered. [ABSTRACT FROM AUTHOR]

Many foraging models assume "perfect information" and "free movement" when describing predator foraging behavior, although this is rare in nature. Here, we quantified predation by brown bears (Ursus arctos Linnaeus, 1758) on adult sockeye salmon (Oncorhynchus nerka (Walbaum, 1792)) in a series of spatially proximate ponds that largely satisfied both assumptions. Salmon abundance varied among years, but pond area and depth were fixed, allowing us to examine interactions between prey abundance and habitat features. We applied versions of two models to 25 years of data on the number and proportion of salmon killed by bears, modifying these models to include habitat features and temporal variability. The functional response model with a year effect fit the data well, indicating bears could take almost all salmon in ponds when salmon were scarce, but bears were sated when salmon were abundant. The proportion of salmon killed by bears was similar across habitats after correcting for pond depth and area. Overall, bears foraged across all habitats but killed higher proportions of salmon in smaller and shallower habitats, consistent with ease of capture. [ABSTRACT FROM AUTHOR]

Maintaining genetic biodiversity is a focal point for conservation of endangered species. As such, reproductive patterns and behaviors are key to understanding how to aid in species conservation. Snake River Sockeye Salmon (Oncorhynchus nerka) are an endangered species with reproductive complexity created by intermixing life history strategies including: anadromous Sockeye Salmon, residual Sockeye Salmon, kokanee, and introgressed populations. We explore the reproductive behaviors, intermixing life history groups, and resulting juvenile production of Pettit Lake O. nerka using genetic stock identification and parentage-based tagging of outmigrating juveniles and returning or released adults. We also compared how production varied between equal and female-biased sex ratio years of adult releases and used this data to explore a sex ratio that can be used to maximize production for management purposes. In this study, Pettit Lake was found to have consistent intermixing between every known life history group in the lake. We determined that a female-biased sex ratio led to larger females selecting for captive males, more production from residual males spawning with captive females, and increased production of age-1 outmigrants. At higher female-biased sex ratios, we found evidence of males spawning with multiple females and an increase in outmigrant production. Our data supports maximizing production by adopting a captive adult release sex ratio of two females per male in a system limited by available adults. These findings provide further understanding on the complexity of reproductive patterns and demonstrate the importance of monitoring and utilizing scientific findings to maximize conservation efforts and management decisions. [ABSTRACT FROM AUTHOR]

As aquatic invasive species spread, their impacts on native systems are variable and important to understand from a management perspective. DNA sequencing and morphological analysis of stomach contents can provide insight into the diet of invasive opportunistic feeders, such as smallmouth bass (Micropterus dolomieu). Since their illegal introduction in 2017, smallmouth bass have proliferated in Cultus Lake, British Columbia and potential impacts on two species-at-risk (sockeye salmon and pygmy sculpin) are currently unknown. Bass (n = 204) were sampled in the spring/summer of 2020–2021 in Cultus Lake. DNA barcoding (n = 145) and visual analysis (n = 204) of diet were completed. Diet composition, factors influencing the predation of species-at-risk, and dietary shifts were analyzed. DNA analysis identified 32 more taxa at the family level than morphological analysis. Multiple logistic regression showed that bass were more likely to predate on Oncorhynchus nerka within the bass spawning grounds, and over 90% of bass had sculpin in their diets. Diet composition did not shift as bass size changed, demonstrating sustained predation on fish from 100 to > 300 mm total length. These results highlight the importance of understanding the potential impacts of an invasive species before investing in suppression to create effective plans and leverage funding opportunities. [ABSTRACT FROM AUTHOR]

In summer, the survival zones of cold‐water species are predicted to narrow by both increasing water temperatures from the surface and by expanding hypoxic zones from the lake bottom. To examine how the abundance of cold‐water fishes changes along environmental gradients, we assessed the vertical environmental DNA (eDNA) distributions of three salmonid species which may have different water temperature tolerances during both stratification and turnover periods using quantitative PCR (qPCR). In addition, we examined on the vertical distribution of diverse fish fauna using an eDNA metabarcoding assay. The results suggested that the kokanee salmon (Oncorhynchus nerka) eDNA were abundant in deep, cold waters. On the other hand, rainbow trout (O. mykiss) eDNA were distributed uniformly throughout the water column, suggesting that they may have high water‐temperature tolerance compared with kokanee salmon. The eDNA concentrations of masu salmon (O. masou) were below the detection limit (i.e., <10 copies μL−1) at all stations and depths and hence could not be quantified during stratification. Together with the finding that the eDNA distributions of other prey fish species were also constrained vertically in species‐specific ways, our results suggest that climate change will result in substantial changes in the vertical distributions of lake fish species and thus affect their populations and interactions. [ABSTRACT FROM AUTHOR]

The article examines reports on the causes of the failure of the Mount Polley copper and gold mine in interior British Columbia on August 4, 2014 to better understand how the attempts to identify the causes still minimize the broader impact of the disaster on Indigenous communities. It explores the effects of the disaster on Indigenous communities drawing from Traci Brynne Voyles's notion of wastelanding. It discusses the framing of Indigenous Peoples as background elements in the disaster.

Genetic monitoring of Pacific salmon in the Columbia River basin provides crucial information to fisheries managers that is otherwise challenging to obtain using traditional methods. Monitoring programs such as genetic stock identification (GSI) and parentage‐based tagging (PBT) involve genotyping tens of thousands of individuals annually. Although rare, these large sample collections inevitably include misidentified species, which exhibit low genotyping success on species‐specific Genotyping‐in‐Thousands by sequencing (GT‐seq) panels. For laboratories involved in large‐scale genotyping efforts, diagnosing non‐target species and reassigning them to the appropriate monitoring program can be costly and time‐consuming. To address this problem, we identified 19 primer pairs that exhibit consistent cross‐species amplification among salmonids and contain 51 species informative variants. These genetic markers reliably discriminate among 11 salmonid species and two subspecies of Cutthroat Trout and have been included in species‐specific GT‐seq panels for Chinook Salmon, Coho Salmon, Sockeye Salmon, and Rainbow Trout commonly used for Pacific salmon genetic monitoring. The majority of species‐informative amplicons (16) were newly identified from the four existing GT‐seq panels, thus demonstrating a low‐cost approach to species identification when using targeted sequencing methods. A species‐calling script was developed that is tailored for routine GT‐seq genotyping pipelines and automates the identification of non‐target species. Following extensive testing with empirical and simulated data, we demonstrated that the genetic markers and accompanying script accurately identified species and are robust to missing genotypic data and low‐frequency, shared polymorphisms among species. Finally, we used these tools to identify Coho Salmon incidentally caught in the Columbia River Chinook Salmon sport fishery and used PBT to determine their hatchery of origin. These molecular and computing resources provide a valuable tool for Pacific salmon conservation in the Columbia River basin and demonstrate a cost‐effective approach to species identification for genetic monitoring programs. [ABSTRACT FROM AUTHOR]

The value of estuaries as nursery habitat for juvenile anadromous salmon is likely variable across estuaries and species. Here, we compiled published empirical data on juvenile salmon estuarine growth and residency. We aimed to quantify the range and variability of these aspects for five species of Pacific salmon across estuaries, methodologies, and life histories. The majority of studies focused on Chinook and coho salmon, largely from their southern range. While there is some evidence of higher growth in wild-origin fish relative to hatchery-origin fish, the wide range of metrics employed made identification of trends among life histories challenging, and unification of reporting could strengthen future research. Different salmon life histories exhibited different residencies, with natural-origin subyearling coho exhibiting the longest mean residency (∼3 months) and 1+ sockeye salmon exhibiting the shortest (3.7 days). Across life histories, hatchery fish exhibited much shorter estuary residencies than wild fish. Collectively, our review highlights key patterns in salmon estuary ecology, identifies knowledge gaps, and lays the foundation for future studies to quantify the importance of estuaries for specific salmon. [ABSTRACT FROM AUTHOR]

Ecological models are used to understand where fishing vessels operate, improving fisheries management success. The ideal free distribution (IFD) predicts equalization of catch across locations in response to distributions of fish and competing vessels. We applied the IFD as a null model to investigate the movement and catch per vessel (CPUE) of the sockeye salmon drift gillnet fleet in Bristol Bay, AK, from 1980 to 2019. The IFD prediction of equal CPUE across areas was not supported, so we explored violations of two assumptions of the theory. We categorized each vessel according to its mobility, highlighting the "free to move" assumption, and found that when we removed nonmobile vessels, some districts had fewer vessels than predicted from their high CPUE. We examined the "equal competitive ability" assumption by calculating the average CPUE, relative to success of other vessels. The underutilization of profitable districts persisted. Overall, the fleet underused high CPUE areas when considering differences in mobility and relative fishing success, indicating that unmeasured safety concerns, travel costs, knowledge of fishing grounds, or other factors could be preventing an IFD. [ABSTRACT FROM AUTHOR]

In this study we explore the unique tripartite collaboration involving the Syilx Okanagan Nation Alliance and the provincial and federal governments, which has been pivotal in restoring Okanagan sockeye salmon Oncorhynchus nerka in British Columbia, Canada. Using qualitative research methods, we analyze the multidimensional challenges the tripartite partnership has faced over its 25-year history, emphasizing the role of traditional ecological knowledge, adaptive co-management, and social learning. We find that a conducive authorizing environment, shared goals, and an unexpected source of financing allowed the Okanagan Sockeye Program to launch. Once underway, the partnership relied on adaptive co-management strategies to navigate inherent complexities and uncertainties. Over time, the attainment of shared objectives and capacity bridging among the partners fostered trust and confidence, enhancing the sustainability of the alliance. Acknowledging the Okanagan Nation Alliance as a legitimate government and maintaining equal decision-making powers were also critical factors; however, Syilx traditional ecological knowledge, as a holistic knowledgepractice-belief system, has been the sustained driving force behind the partnership. Over the multi-decade trajectory, the alliance grappled with institutional complexities surrounding jurisdictional conflicts, power imbalances, and systemic inequities. At a time when Indigenous co-management in Canada is at a crossroads, and demands for Indigenous environmental governance are only increasing, this study offers some insights. Our research invites further exploration into the successes and failures of Indigenous environmental governance and co-management schemes, with a view to informing future policy and programming. [ABSTRACT FROM AUTHOR]

Evaluating salmon hatchery supplementation programs requires assessing not only program objectives but identifying potential risks to wild populations as well. Such evaluations can be hampered by difficulty in distinguishing between hatchery‐ and wild‐born returning adults. Here, we conducted 3 years (2011–2013) of experimental hatchery supplementation of sockeye salmon in Auke Lake, Juneau, Alaska where a permanent weir allows sampling and genotyping of every returning adult (2008–2019). We identified both hatchery‐ and wild‐born returning adults with parentage assignment, quantified the productivity (adult offspring/spawner) of hatchery spawners relative to that of wild spawners, and compared run timing, age, and size at age between hatchery‐ and wild‐born adults. Hatchery‐spawning females produced from approximately six to 50 times more returning adults than did naturally spawning females. Supplementation had no discernable effect on run timing and limited consequences for size at age, but we observed a distinct shift to younger age at maturity in the hatchery‐born individuals in all three brood years. The shift appeared to be driven by hatchery‐born fish being more likely to emigrate after one, rather than two, years in the lake but the cause is unknown. In cases when spawning or incubation habitat is limiting sockeye salmon production, hatchery supplementation can be effective for enhancing the number of returning adult fish but not without the risk of phenotypic change in the recipient population, which can be an undesired outcome of hatchery supplementation. This study adds to a growing body of evidence suggesting that phenotypic change within a single generation of captive spawning might be widespread in salmon hatchery programs. [ABSTRACT FROM AUTHOR]

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 change. Kokanee salmon, the non‐migratory ecotype of sockeye salmon (Oncorhynchus nerka), is culturally and economically important and has already been impacted by the effects of climate change. To assess its climate vulnerability moving forward, we integrated analyses of standing genetic variation, genotype‐environment associations, and climate modeling based on sequence and structural genomic variation from 224 whole genomes sampled from 22 lakes in British Columbia and Yukon (Canada). We found that variables for extreme temperatures, particularly warmer temperatures, had the most pervasive signature of selection in the genome and were the strongest predictors of levels of standing variation and of putatively adaptive genomic variation, both sequence and structural. Genomic offset estimates, a measure of climate vulnerability, were significantly correlated with higher increases in extreme warm temperatures, further highlighting the risk of summer heat waves that are predicted to increase in frequency in the future. Levels of standing genetic variation, an important metric for population viability and resilience, were not correlated with genomic offset. Nonetheless, our combined approach highlights the importance of integrating different sources of information and genomic data to formulate more comprehensive and accurate predictions on the vulnerability of populations and species to future climate change. [ABSTRACT FROM AUTHOR]

Introduction: The food-energy-water (FEW) nexus highlights the interdependencies between the systems that people rely on for these essential resources. For example, globally, over two thirds of freshwater withdrawals are used to produce food, and another 10% is used during energy generation. In addition, the food system uses one eighth of global net energy. Seafood is a nutritionally important food, and it is critical to use freshwater and energy resources efficiently throughout seafood supply chains to safeguard future supplies and to reduce environmental impacts. Diverse seafood production methods result in highly variable resource use across supply chains, which may contribute to siloed efforts within supply chains to improve efficiency, instead of larger efforts that involve multiple seafood supply chains. Additionally, efforts to develop and implement efficiency strategies must be informed by fishers, aquaculturists, processors, and other seafood supply chain actors to avoid investing time and resources into strategies that will have low uptake. A significant proportion of seafood is imported into the U.S., so engaging with industry and stakeholders in the U.S. and abroad is critical for understanding and improving the FEW nexus associated with seafood consumed by Americans. Methods: To understand how resources are being used, current and potential strategies to improve resource use, and relevant motivations and barriers, we conducted 47 semi-structured interviews from 2019 to 2021 with seafood supply chain actors, including producers and processors. Seafood supply chains included were farmed catfish produced in the U.S., farmed pangasius and shrimp produced in Vietnam, farmed Atlantic salmon produced in Norway, and wild-caught sockeye and pink salmon caught in the U.S. Results: We provide detailed descriptions of stages within each supply chain regarding resource use and efficiency strategies, and report higher-level findings that apply across supply chains. There was variation across settings regarding how resources are used and opportunities and barriers for improving efficiencies, but we also found commonalities in settings, indicating that resource-saving strategies or innovations could lead to increased efficiency across multiple supply chains. Interviewees shared that cost savings drove past adoption of, and high interest in, energy conservation practices. Generally, direct costs did not motivate reduced use of freshwater, but associated costs like energy to run pumps and supplies to treat contaminated surface water drove interest in reducing water use. Discussion: Efforts to improve resource use in the U.S. seafood supply should focus on identifying and scaling-up strategies that (i) involve improved efficiency of more than one resource and/or (ii) apply across multiple settings. This work should involve partnerships between industry, government agencies, and academic researchers, and should be informed by supply chain actors' experiences and insights. The qualitative insights from this study encompass rich descriptions of FEW-relevant factors at the level of specific supply chain stages as well as findings across six major seafood supply chains in three countries. The study provides an essential complement to existing quantitative characterizations of resource use, and enables nuanced and informed responses to challenges. [ABSTRACT FROM AUTHOR]

The impacts of climate change are widespread and threaten natural systems globally. Yet, within regions, heterogeneous physical landscapes can differentially filter climate, leading to local response diversity. For example, it is possible that while freshwater lakes are sensitive to climate change, they may exhibit a diversity of thermal responses owing to their unique morphology, which in turn can differentially affect the growth and survival of vulnerable biota such as fishes. In particular, salmonids are cold‐water fishes with complex life histories shaped by diverse freshwater habitats that are sensitive to warming temperatures. Here we examine the influence of habitat on the growth of sockeye salmon (Oncorhynchus nerka) in nursery lakes of Canada's Skeena River watershed over a century of change in regional temperature and intraspecific competition. We found that freshwater growth has generally increased over the last century. While growth tended to be higher in years with relatively higher summer air temperatures (a proxy for lake temperature), long‐term increases in growth appear largely influenced by reduced competition. However, habitat played an important role in modulating the effect of high temperature. Specifically, growth was positively associated with rising temperatures in relatively deep (>50 m) nursery lakes, whereas warmer temperatures were not associated with a change in growth for fish among shallow lakes. The influence of temperature on growth also was modulated by glacier extent whereby the growth of fish from lakes situated in watersheds with little (i.e., <5%) glacier cover increased with rising temperatures, but decreased with rising temperatures for fish in lakes within more glaciated watersheds. Maintaining the integrity of an array of freshwater habitats—and the processes that generate and maintain them—will help foster a diverse climate‐response portfolio for important fish species, which in turn can ensure that salmon watersheds are resilient to future environmental change. [ABSTRACT FROM AUTHOR]

Many salmon species are monitored by visual counts of spawners in streams; however, there are few data sets where abundance is known and compared to estimates derived from visual counts. We used spawner fences to obtain known kokanee (Oncorhynchus nerka) spawner abundance (14 stream-years) on streams that are monitored with annual visual surveys (7 to 9 counts per year) and incorporated similar published data from pink salmon (Oncorhynchus gorbuscha) (11 stream-years). We investigated the performance of several simplified expansion factor estimation methods with survey life and observer efficiency as unknown nuisance parameters. All visual indices of kokanee and pink salmon spawners from live ground counts were highly correlated to abundance from fence counts (r2 ≥ 0.96 and 0.89, respectively). Application of cross-validation on out-of-sample data for both species showed that mean% error could range from 13% to 53% on a previously unsampled stream depending on the species, counting method, and visual index used. Predictive performance metrics were less sensitive to counting frequency than observer efficiency and associated variability, which was influenced by the counting method (aerial versus ground surveys). [ABSTRACT FROM AUTHOR]

Environmental laws around the world require some version of an environmental‐impact assessment surrounding construction projects and other discrete instances of human development. Information requirements for these assessments vary by jurisdiction, but nearly all require an analysis of the biological elements of ecosystems. Amplicon‐sequencing—also called metabarcoding—of environmental DNA (eDNA) has made it possible to sample and amplify the genetic material of many species present in those environments, providing a tractable, powerful, and increasingly common way of doing environmental‐impact analysis for development projects. Here, we analyze an 18‐month time series of water samples taken before, during, and after two culvert removals in a salmonid‐bearing freshwater stream. We also sampled multiple control streams to develop a robust background expectation against which to evaluate the impact of this discrete environmental intervention in the treatment stream. We generate calibrated, quantitative metabarcoding data from amplifying the 12s MiFish mtDNA locus and complementary species‐specific quantitative PCR data to yield multispecies estimates of absolute eDNA concentrations across time, creeks, and sampling stations. We then use a linear mixed effects model to reveal patterns of eDNA concentrations over time, and to estimate the effects of the culvert removal on salmonids in the treatment creek. We focus our analysis on four common salmonid species: cutthroat trout (Oncorhynchus clarkii), coho salmon (Oncorhynchus kisutch), rainbow trout (Oncorhynchus mykiss), and sockeye salmon (Oncorhynchus nerka). We find that one culvert in the treatment creek seemed to have no impact while the second culvert had a large impact on fish passage. The construction itself seemed to have only transient effects on salmonid species during the two construction events. In the context of billions of dollars of court‐mandated road culvert replacements taking place in Washington State, USA, our results suggest that culvert replacement can be conducted with only minimal impact of construction to key species of management concern. Furthermore, eDNA methods can be an effective and efficient approach for monitoring hundreds of culverts to prioritize culverts that are required to be replaced. More broadly, we demonstrate a rigorous, quantitative method for environmental‐impact reporting using eDNA that is widely applicable in environments worldwide. [ABSTRACT FROM AUTHOR]

The spawning stock of sockeye salmon in the Bolshaya River is evaluated for 1929–2022. Long-term tendencies are determined for their most important biological parameters, in particular, a juvenilization of returning spawners with decreasing of their body size, weight, and fecundity. Possible causes of these processes are considered. Biological indices of the sockeye salmon belonged to different races, ecological forms, ecotypes, and genders are compared statistically for different periods of time, with the frequency analysis. Changes in the size and age structure are revealed — range of the size and age variability has decreased. The age structure in the sea adjacent to the Bolshaya River mouth contradicts the hypothesis of a significant portion of sockeye salmon from Lake Kurilskoye in seine by-catch. The sockeye salmon abundance has changed periodically and recently is at the top of the wave. Compared to the 1929–2000 average, the stock has increased 6–7 times by 2020, and more than tenfold in 2022, whereas the average multiplicity of reproduction has increased 9 times (such a high value is obviously due to underestimation of spawning).

Proposed development of a mine within Alaska's Bristol Bay watershed (USA) has raised concerns about the potential impact of copper (Cu) on Pacific salmon (Oncorhynchus spp.). We conducted 96‐h flow‐through bioassays using low‐hardness and low dissolved organic carbon water to determine the acute lethal toxicity of Cu to sockeye (Oncorhynchus nerka), Chinook (Oncorhynchus tshawytscha), and coho salmon (Oncorhynchus kisutch) fry. We aimed to determine Cu toxicity under field‐relevant water quality conditions and to assess three methods of calculating ambient Cu criteria: the biotic ligand model (BLM), a multiple linear regression model endorsed by the US Environmental Protection Agency, and the hardness‐based model currently used by the State of Alaska. The criteria generated by all models were below 20% lethal Cu concentrations by factors ranging from 2.2 to 54.3, indicating that all criteria would be protective against mortality. The multiple linear regression‐based criteria were the most conservative and were comparable to BLM‐based criteria. The median lethal concentrations (LC50s) for sockeye, Chinook, and coho were 35.2, 23.9, and 6.3 µg Cu/L, respectively. We also used the BLM to predict LC50s for each species. Model predictions differed from empirical LC50s by factors of 0.7 for sockeye and Chinook salmon, and 1.1 for coho salmon. These differences fell within the acceptable range of ±2, indicating the model's accuracy. We calculated critical lethal Cu accumulation values for each species to account for differing water chemistry in each bioassay; the present study revealed that coho salmon were most sensitive to Cu, followed by sockeye and Chinook salmon. Our findings underscore the importance of considering site‐ and species‐specific factors when modeling Cu toxicity. The empirical data we present may enhance Cu risk assessments for Pacific salmon. Environ Toxicol Chem 2023;42:2440–2452. © 2023 SETAC [ABSTRACT FROM AUTHOR]