Growth Of Salmon Research Articles

Genomic prediction accuracy of growth in Atlantic salmon (Salmo salar) when genotype-by-environment interaction is present

Genomic prediction accuracy of growth in Atlantic salmon (Salmo salar) when genotype-by-environment interaction is present

Effects of fishmeal substitution with defatted black soldier fly larvae and soy protein meals on the growth, physio-biochemical responses, and immune-related gene expression of Atlantic salmon (Salmo salar)

Effects of fishmeal substitution with defatted black soldier fly larvae and soy protein meals on the growth, physio-biochemical responses, and immune-related gene expression of Atlantic salmon (Salmo salar)

Spatial variation in age-specific growth of female Chinook salmon

Spatial variation in age-specific growth of female Chinook salmon

Restored seasonally inundated habitat supports juvenile salmonid rearing and growth in two California Central Valley rivers

ABSTRACT Objective River habitat restoration projects are implemented throughout western North America to mitigate the long-term effects of anthropogenic disruptions on native salmonid (Salmonidae) populations. However, relatively little is known about the target species’ physiological or behavioral responses to habitat enhancement. We constructed four seasonally inundated habitat restoration projects in the Merced (8.5 ha) and Stanislaus (2.2 ha) rivers in California’s Central Valley. We hypothesized that increasing seasonal shallow-water habitat area would increase the quantity and quality of rearing habitat, improving juvenile salmonid rearing, growth, and variation in migration timing and body size. Methods To test our hypotheses, we compared invertebrate prey abundance and juvenile density, residence time, and growth of Chinook Salmon Oncorhynchus tshawytscha in restored seasonal habitats and the unrestored main channel. Results Invertebrate prey productivity in restored seasonally inundated habitat was variable but generally comparable to that in the main channel. In both rivers, restored seasonal habitats supported increased total salmon growth through increased residence time in wet years and faster growth rates in a below-normal precipitation year and a greater diversity in out-migration timing across all study years. Conclusions This study demonstrates that expanded seasonally inundated habitats support invertebrate prey production and are used by juvenile salmon. All sites supported natal rearing and growth, but the strength of restoration response varied by site, flow conditions, and metric. Data for rearing behavior and growth parameters of juvenile Chinook Salmon can be incorporated into existing models to better predict the rearing capacity and growth and survival benefits of seasonally inundated habitat in these and other Mediterranean-climate rivers.

Is Early Marine Growth Related to Salmon Survival? Two Decades of Data from Juvenile Coho Salmon in the Northern California Current

Early summer growth for juvenile coho salmon (Oncorhynchus kisutch) has been assessed in the Northern California Current (NCC) since 2000. Mean insulin-like growth factor 1 (IGF1) levels (an indicator of growth) differed significantly over succeeding decadal intervals (2000–2009 vs. 2011–2022) with IGF1 levels since 2010 being consistently higher than found before 2010. Across the time series, IGF1 levels were correlated with a prey index for juvenile salmon derived from plankton samples collected in the upper water column during juvenile salmon surveys. There are no apparent correlations between juvenile salmon growth and basin-scale oceanographic indictors including the Pacific Decadal Oscillation (PDO), Northern Pacific Gyre Oscillation (NPGO) or Oceanic Niño Index (ONI). Neither is there a correlation between juvenile salmon growth and upper water column temperatures concurrent with the survey. From 2000–2009 early marine growth was correlated with an index of coho salmon survival (OPIH), there was no correlation of growth with survival in the subsequent decade (2011–2022). These data don’t easily fit with current paradigms suggesting that variation in juvenile salmon growth and survival is correlated with California Current ecosystem productivity driven by variation in basin-scale ocean processes indexed as by the PDO or NPGO. Indeed, the highest IGF1 level measured in the time series were unexpectedly found during the 2016 El Niño. Together, these data suggest that there isn’t a simple relationship between early marine growth and survival for coho salmon in the NCC. Moreover, any relationship that does exist changed over a decadal time scale (2000–2009 vs. 2011–2022). Finally, it may be difficult to establish mechanistic insights into growth and survival within the framework of current environmental variation in the NE Pacific Ocean.

Production Trend of Hokkaido Chum Salmon Estimated by Multivariable Models Incorporating Environmental Factors and Biological Interactions in the North Pacific Ocean

Global warming continues unabated. The global annual mean of sea surface temperature (SST) is increasing at a rate of 0.6ºC per century, and was the highest on record in 2023. SST in the North Pacific Ocean has warmed by about 1ºC over the past 120 years. Pacific salmon (Oncorhynchus spp.) play an important role as a keystone species and provider of ecosystem services in North Pacific ecosystems. Their total catch has shown an increasing trend since the late 1970s. However, in this century, the abundance of Pacific salmon has decreased in southern areas and increased in northern areas due to the effects of global warming. In particular, the abundance of Hokkaido chum salmon (O. keta) has decreased since the 2000s (Kaeriyama 2023). On the other hand, in the Bering Sea, the marked increase in pink salmon abundance has negatively impacted trophic cascades through the top-down effect by reducing herbivorous zooplankton abundance sufficiently to increase phytoplankton densities (Ruggerone et al. 2023) and low growth of sockeye salmon (O. nerka) (Rand and Ruggerone 2024). Japanese chum salmon are a southernmost population, and they migrate widely, inhabiting different ecosystems in the North Pacific and adjacent seas, depending on their life stage and season (Urawa et al. 2018). This complicated life history makes it difficult to understand the mechanisms of their population dynamics. The objective of this study is to discuss how the marine life history of Hokkaido chum salmon is affected by marine environmental factors such as inter- and intraspecific interactions among Pacific salmon, SST, and zooplankton biomass using various models, and to predict their future production trends.

Managing flows for sockeye salmon emergence using the Fish Water Management Tool

The Fish Water Management Tool (FWMT) is a water management decision support tool designed in part to protect sq̓awsitkʷ|Okanagan River sockeye salmon (sćwin|Oncorhynchus nerka). The FWMT includes a sockeye salmon sub-model to predict emergence timing, a life history stage where sockeye salmon are particularly vulnerable to high (scour) or low (desiccation) flows. Field observations of fry emergence timing were used to evaluate the accuracy of the FWMT sub-model, as well as flow data, spawner data and acoustic trawl data to evaluate the effectiveness of the FWMT. The FWMT predicted the date of peak emergence within an average of 12.6 days and improved compliance with flow targets by reducing desiccation and scour flows during incubation and fry migration life stages. Overall, the FWMT provides a flexible framework that allows water managers to evaluate and react to sq̓awsitkʷ|Okanagan River sockeye salmon responses to environmental conditions, rather than being constrained to a rigid calendar. These efforts have increased compliance with key flow targets, resulting in improved fry recruitment and a rare success story for fishery recovery.

Seasonal dynamics of juvenile coho salmon (Oncorhynchus kisutch) in wetlands of the North Thompson River, British Columbia

Freshwater fish such as juvenile salmon often rely on dynamic and diverse habitats such as wetlands. Although juvenile salmon wetland use is well documented, their use of freshwater wetlands in large river networks that vary in isolation and connection is not well known. We studied juvenile coho salmon use of three wetland sites along the North Thompson River, British Columbia, Canada, from May 2021 to October 2023 to understand how seasonal variation in wetland connectivity and water quality (temperature and dissolved oxygen) influence juvenile coho salmon habitat use. We used monthly mark–recapture sampling to estimate juvenile coho salmon abundance and density. Seasonal abundance and growth of juvenile coho salmon in wetlands were intertwined with connectivity and abiotic conditions. Age-0 juvenile coho salmon were recruited to wetlands during high spring flows and used wetland habitats year-round. Periods of high density and low oxygen were associated with lower growth and abundance. Our study also provides information on the timing of juvenile coho salmon use of wetland habitats, which can be used to inform habitat managers of times of year that pose the greatest risk and benefits to these fish.

Reconstructing salmon growth trajectories through biochronologies across a highly variable growthscape

Measuring the growth of migratory fish across habitats is difficult because field observations only provide a snapshot into their life; yet, understanding which habitats provide better growth opportunities is crucial for their conservation. We experimentally enclosed individually tagged juvenile Chinook salmon ( Oncorhynchus tshawytscha) in habitats with known differences in growth potentials to evaluate four different models (Dahl–Lea, Fraser–Lee, Biological Intercept, and Modified Fry) used to back-calculate size-at-age from otoliths. We found that otolith-derived fish size reconstructions were most accurate using the Biological Intercept or Modified Fry model, though bias remains for slow growing fish. This tool was then used in a case study to reconstruct the mosaic of inter- and intra-habitat growth opportunities available to fishes, providing a useful framework for assessing and monitoring fish responses to habitat restoration and a changing environment.

Regional differences in salmon post-smolt migration routes can explain variation in individual growth at sea

The low number of Atlantic salmon sampled at sea makes it necessary to use alternative methods to understand their migration routes and interactions with the marine environment. In this study, we use a newly developed individual based model to simulate the ocean migration of Norwegian post-smolts during their first summer in the sea. The model is coupled with a high-resolution hydrodynamic model and dynamic prey fields to investigate how interactions between post-smolts and the dynamic marine environment in the Northeast Atlantic Ocean affect salmon growth and survival. The migration strategy leading to the best fit between the simulated geographic distribution and catches of post-smolts at sea, is to migrate away from shallow, coastal regions and to follow surface currents. Post-smolts originating from the middle parts of Norway can quickly reach the good feeding areas west of the Norwegian continental shelf, while post-smolts leaving rivers further south must start the marine life-stage migrating through the North Sea, where the prey abundance is low, before reaching the feeding areas in the Norwegian Sea. The results indicate that the first weeks at sea is a critical period for post-smolts as the available prey abundance is low, especially for smolts leaving rivers in southern and western Norway. A rapid northward migration to the central or northern Norwegian Sea is associated with faster growth for smolt emigrating from rivers flowing into the North Sea. The presented model is a first attempt to couple salmon and their marine prey in a spatiotemporal model covering the Northeast Atlantic Ocean.

A holo-omics analysis shows how sugar kelp can boost gut health in Atlantic salmon

A holo-omics analysis shows how sugar kelp can boost gut health in Atlantic salmon

Correction to: Understanding freshwater to marine transitional scale growth in Atlantic salmon (Salmo salar)

Correction to: Understanding freshwater to marine transitional scale growth in Atlantic salmon (<i>Salmo salar</i>)

Effects of dietary Bacillus pumilus on the growth, intestinal health, lipid metabolism, and mTOR signaling pathway of juvenile coho salmon (Oncorhynchus kisutch)

Effects of dietary Bacillus pumilus on the growth, intestinal health, lipid metabolism, and mTOR signaling pathway of juvenile coho salmon (Oncorhynchus kisutch)

Understanding freshwater to marine transitional scale growth in Atlantic salmon (Salmo salar)

Abstract The first marine circulus is the scale feature associated with marine entry and has been used to support research evaluating the relationships between size, growth, and survival for Atlantic salmon. Ambiguity in growth rates and circulus deposition during the transition from freshwater to the marine environment leads to difficulty in the correct identification of the first marine circulus. In this study, scale growth occurring after the last freshwater annulus (plus-growth) was characterized for Atlantic salmon smolts migrating out of the Narraguagus River in Maine. Plus-growth was present in over 95% of scales from smolts leaving the river and represented on average 12.2% of total freshwater growth. These findings suggest plus-growth presents a significant source of error in growth analyses, if ignored, and the characterization of this scale feature helps to inform accurate identification of marine entry for future studies. Run day was a driver of plus-growth, suggesting extended freshwater residency provides opportunity for growth prior to smolt emigration. The negative association between fork length and plus-growth suggests smaller smolts that delay migration are demonstrating compensatory growth. Cumulative air temperature was positively associated with plus-growth, suggesting warming spring temperatures driven by climate change may influence size at marine entry for smolts.

Selection for heat tolerance in Atlantic salmon (Salmo salar) using reaction norms

Selection for heat tolerance in Atlantic salmon (Salmo salar) using reaction norms

Juvenile coho salmon growth differences track biennial pink salmon spawning patterns

Abstract Spawning Pacific salmon (Oncorhynchus spp.) provide marine‐derived resources (MDR) to freshwater food webs in the form of eggs, flesh and maggots that consume salmon carcasses, all of which positively impact stream‐dwelling fish growth. Pink salmon (O. gorbuscha) are widely distributed throughout coastal catchments along the North Pacific Ocean and display increased spawning abundances in odd years, owing to a fixed 2‐year life history. While many studies have found that foraging and growth of stream‐dwelling salmonids are improved by increased adult salmon spawning abundance, few studies have investigated the importance of alternating pink salmon spawning abundance between years. Here, we examined how patterns of pink salmon spawning abundance impact the foraging and growth of juvenile coho salmon (O. kisutch). First, we used bioenergetic simulations to generate a hypothesis that coho salmon growth would increase during odd relative to even years. We then collected empirical juvenile coho salmon diet and growth data from a Southeast Alaska catchment in 2021 (pink salmon spawning) and 2022 (no pink salmon spawning). Field data were compared against simulation predictions to understand impacts of biennial pink salmon spawning patterns on juvenile coho salmon growth. Empirical growth data revealed similar patterns to bioenergetic simulations. Age‐1 coho salmon grew 16.6 mm longer and 5.5 g heavier on average in 2021 compared to 2022. Age‐0 coho salmon displayed minor growth differences between years. These results support bioenergetic model predictions and suggest that patterns of pink salmon spawning abundance can impart interannual growth disparities to juvenile coho salmon. Moreover, we show that distinct spawning characteristics of Pacific salmon species are important when understanding patterns of MDR transfer and growth responses in stream fishes.

Nutritional evaluation of an aqueous-processed canola protein concentrate in diets of Atlantic Salmon Salmo salar at different life stages

Nutritional evaluation of an aqueous-processed canola protein concentrate in diets of Atlantic Salmon Salmo salar at different life stages

Full-fat black soldier fly larvae meal and yellow mealworm meal: Impact on feed protein quality, growth and nutrient utilization of Atlantic salmon (Salmo salar) post smolts

Full-fat black soldier fly larvae meal and yellow mealworm meal: Impact on feed protein quality, growth and nutrient utilization of Atlantic salmon (Salmo salar) post smolts

Evaluation of sampling bias in growth and skin health assessment methods of New Zealand-farmed king salmon (Oncorhynchus tshawytscha)

Evaluation of sampling bias in growth and skin health assessment methods of New Zealand-farmed king salmon (Oncorhynchus tshawytscha)

Automated computer vision based individual salmon (Salmo salar) breathing rate estimation (SaBRE) for improved state observability

Automated computer vision based individual salmon (Salmo salar) breathing rate estimation (SaBRE) for improved state observability