Distribution Of Salmon Research Articles

Winter Distribution of Chum Salmon in the Gulf of Alaska: A Review

Winter Distribution of Chum Salmon in the Gulf of Alaska: A Review

Effects of Radio Frequency Tempering on the Temperature Distribution and Physiochemical Properties of Salmon (Salmo salar).

Salmon (Salmo salar) is a precious fish with high nutritional value, which is perishable when subjected to improper tempering processes before consumption. In traditional air and water tempering, the medium temperature of 10 °C is commonly used to guarantee a reasonable tempering time and product quality. Radio frequency tempering (RT) is a dielectric heating method, which has the advantage of uniform heating to ensure meat quality. The effects of radio frequency tempering (RT, 40.68 MHz, 400 W), water tempering (WT + 10 °C, 10 ± 0.5 °C), and air tempering (AT + 10 °C, 10 ± 1 °C) on the physiochemical properties of salmon fillets were investigated in this study. The quality of salmon fillets was evaluated in terms of drip loss, cooking loss, color, water migration and texture properties. Results showed that all tempering methods affected salmon fillet quality. The tempering times of WT + 10 °C and AT + 10 °C were 3.0 and 12.8 times longer than that of RT, respectively. AT + 10 °C produced the most uniform temperature distribution, followed by WT + 10 °C and RT. The amount of immobile water shifting to free water after WT + 10 °C was higher than that of RT and AT + 10 °C, which was in consistent with the drip and cooking loss. The spaces between the intercellular fibers increased significantly after WT + 10 °C compared to those of RT and AT + 10 °C. The results demonstrated that RT was an alternative novel salmon tempering method, which was fast and relatively uniform with a high quality retention rate. It could be applied to frozen salmon fillets after receiving from overseas catches, which need temperature elevation for further cutting or consumption.

Complementary distribution of non-native white-spotted charr and native red-spotted masu salmon in Shikoku Island, southwestern Japan: a consequence of interspecific interactions?

Complementary distribution of non-native white-spotted charr and native red-spotted masu salmon in Shikoku Island, southwestern Japan: a consequence of interspecific interactions?

The Spatial Distribution and Morphological Characteristics of Chum Salmon (Oncorhynchus keta) in South Korea

Chum salmon (Oncorhyncus keta) is a cold-water species reported to migrate within a wide range of habitats, including Korea, Japan, North America, and Russia, playing important roles in the river–sea nutrient cycle and food web. However, research on this species has not been widely performed in South Korea owing to its geographical location at the southern edge of migration. In this study, we analyzed the spatial distribution and morphological characteristics of chum salmon migrating to South Korea using the length–weight relationship. We also analyzed 3 years of catch, sex ratio, and individual information (total length (cm), weight (kg), n = 4400) from ten rivers (eight in the East coast and two on the South coast) with a total of 17 years of water quality and the distance they traveled (n = 50) using multivariate analysis. As a result, we discovered a trend of less migration in the southern part of South Korea for all individuals migrating to South Korea. Furthermore, the weight ratio of males/females was significantly different (p < 0.05). Based on the length–weight relationship analysis, the a and b values were between 0.0011 and 0.038 and 2.65 and 3.49, respectively. In the correlation analysis, catch is negatively correlated with distance traveled and temperature (p < 0.05), and positively correlated with pH, dissolved oxygen, distance, and female ratio (p < 0.05). This is possibly the result of differences in water quality during early life stages or the presence of an estuarine barrage at the mouth of the Nakdong River. This research may be used as fundamental distribution and morphological variations of chum salmon in South Korea.

Nocturnal distributions of juvenile Pacific salmon along an eco-engineered marine shoreline

Nocturnal distributions and habitat preferences of juvenile fish along urban shorelines are understudied relative to daytime investigations. As a case study, nocturnal distributions of juvenile Pacific salmon (Oncorhynchus spp.) among ecological engineered and conventional seawall and pier habitats were characterized from May through August 2019 along the Seattle, WA, USA, waterfront. A multibeam sonar mounted beneath a kayak enabled day-night fish density comparisons to identify distribution and habitat use differences. Ecological engineering included mattresses (mesh bags filled with rocks) to create intertidal benches, a textured seawall to increase invertebrate colonization, and embedded glass blocks in an overhanging sidewalk to increase ambient light. Overall juvenile salmon night presence was twice that of daytime, and counts were 1.5 times higher during peak salmon densities. Juvenile salmon presence in eco-engineered and reference habitats was more similar at night compared to day. At night, juvenile salmon avoided traditional under-pier habitats and were more likely to navigate around piers that lack nearshore eco-engineered habitats. Increased use of eco-engineered habitats by juvenile salmon at night highlights the need to incorporate diel fish distribution differences in resource abundance estimates, and in the design and construction of coastline modifications.

Spatial distribution of chum salmon spawning redds in a non-stocked river with an artificial structure

Spatial distribution of chum salmon spawning redds in a non-stocked river with an artificial structure

The Effect of Frozen Storage on the Quality of Atlantic Salmon

Salmon is a nutritious fish food high in omega-3 fatty acids and is highly sought for its unique sensory attributes. Long term frozen storage allows the widespread distribution of salmon to improve the economic situation of this industry and avail a greater population to the nutritional benefits of salmon. The purpose of this research was to determine the quality changes in Atlantic Salmon stored at different freezer temperatures over 12 months. Fresh and pre-frozen salmon were placed in five different freezers set at -7°C, -12°C, -18°C, -29°C and -77°C and evaluated for quality at 90, 180, 270 and 360 days of storage. In general, quality was retained to a greater extent in salmon held at -29°C and -77°C for 360 days compared to other storage temperatures. No significant difference between freezer -29°C and -77°C was found in weight loss at days 180, 270 and 360, pore size at days 270 and 360, and for water holding capacity, texture and TBARS, at days 90, 180, 270 and 360. The predicted shelf life of freshly frozen Atlantic Salmon was calculated based on the zero-order reaction model which was 268.82 days-7°C; 297.61 days-12°C; 355.78 days-18°C; 438.02 days-29°C, and 424 days-77°C. While the shelf life of pre-frozen Atlantic Salmon was 271.28 days- 7°C; 281.77 days-12°C; 351.33 days-18°C; 392.59 days-29°C; and 402.99 days-77°C. Based on several quality parameters having minimal variation between 4 to 9 months at home freezer temperatures, energy savings could be realized by use of higher freezer temperatures for storage of salmon.

The early marine distribution of Atlantic salmon in the North-east Atlantic: a genetically informed stock-specific synthesis

The early marine distribution of Atlantic salmon in the North-east Atlantic: a genetically informed stock-specific synthesis

Downstream Migration and Spatial Distribution of Juvenile Chum Salmon in the Otsuchi Bay, the Sanriku Coast of Iwate, Japan

Downstream Migration and Spatial Distribution of Juvenile Chum Salmon in the Otsuchi Bay, the Sanriku Coast of Iwate, Japan

Dynamics on Distribution, Production, and Biological Interactions of Pacific Salmon in the Changing Climate of the North Pacific Ocean

Dynamics on Distribution, Production, and Biological Interactions of Pacific Salmon in the Changing Climate of the North Pacific Ocean

Spatial distribution and interannual variability of catches for pink salmon of artificial origin in the waters of eastern coast of Sakhalin Island in modern times

Mixed herds of pink salmon including the fish of both artificial and natural origin are exploited by fishery in many areas of Sakhalin Island. To separate the fish of different origin, large-scale tagging of the juveniles otoliths is conducted at salmon hatcheries since 2008. The hatcheries contribution to pink salmon catches in certain areas of East Sakhalin (from the Langeri River to Cape Crillon) is assessed for 2011–2017 on the base of previously published and new data on occurrence of the fish with marked otoliths. The specimens were sampled from commercial catches of 5–13 fixed nets and from research catches in 5–9 rivers throughout entire spawning season. In total, 40,992 otoliths of pink salmon were collected. The otoliths were prepared for microstructure analysis using standard methods of processing. All marked otoliths had the tags of hatcheries located on the eastern coast of Sakhalin. The fish of artificial origin were caught in all examined sites between Cape Soymonov and Cape Crillon every year, but in some years their distribution was wider, up to the northern limit of the investigated area (Langeri River). The fish of artificial origin migrated to all rivers within this area. The total annual landing of the pink salmon marked at artificial hatcheries in the East Sakhalin waters was estimated as 300–10600 t, by years. The rest of the fish of artificial origin (0.4–2.3 . 106 ind.) entered to the rivers and mostly reached the spawning grounds. Long-term dynamics of landing was compared for the pink salmon of artificial and natural origin and their independence was concluded. Distribution of pink salmon originated from certain artificial hatcheries by sites of catch was rather constant that allowed to extrapolate the results for marked fish to all released pink salmon. The highest contribution of pink salmon of artificial origin was noted for catches in the Aniva Bay (23.9 %, on average), it was lower for catches at the southeastern coast of Sakhalin (13.2 %), and more lower for catches in the Patience Bay (7.6 %). Total number of pink adults of artificial origin caught on a particular stretch of coast did not depend directly on the number of pink juveniles released from a local hatchery, but was determined mainly by number of fish migrated there from other hatcheries. The landing of pink salmon originated from artificial hatcheries directly in the rivers where these hatcheries were located and at their mouths was < 10 % of the total catch of pink salmon of artificial origin. Schemes of quantitative distribution of pink salmon with marked otoliths in the waters of East Sakhalin are presented.

The early marine distribution of Atlantic salmon in the North‐east Atlantic: A genetically informed stock‐specific synthesis

AbstractThe survival of Atlantic salmon (Salmo salar), an increasingly rare anadromous species, has declined dramatically during its marine phase, with disproportionate impacts on the poorly understood early post‐smolt period. Logistical constraints on collecting oceanic data to inform this issue pose a formidable obstacle. To advance understanding of post‐smolt distributional ecology in the North‐east Atlantic, a comprehensive analysis of existing information was undertaken. Data were synthesized from 385 marine cruises, 10,202 individual trawls, and 9,269 captured post‐smolts, spanning three decades and ~4.75 million km2 of ocean, with 3,423 individuals genetically assigned to regional phylogeographic origin. The findings confirm major migrational post‐smolt aggregations on the continental shelf‐edge off Ireland, Scotland and Norway, and an important marine foraging area in the Norwegian Sea. Genetic analysis shows that aggregational stock composition does not simply reflect distance to natal rivers, with northern phylogeographic stock groups significantly under‐represented in sampled high‐seas aggregations. It identifies a key foraging habitat for southern European post‐smolts located in international waters immediately west of the Vøring Plateau escarpment, potentially exposing them to a high by‐catch mortality from extra‐territorial pelagic fisheries. Evidence of the differential distribution of regional stocks points to fundamental differences in their migration behaviours and may lead to inter‐stock variation in responses to environmental change and marine survival. The study shows that understanding of post‐smolt marine ecology, as regards to stock‐specific variations in habitat utilization, biological performance and exposure to mortality factors, can be significantly advanced by data integration across studies and exploiting genetic approaches.

Redefining the oceanic distribution of Atlantic salmon

Determining the mechanisms driving range-wide reductions in Atlantic salmon marine survival is hindered by an insufficient understanding of their oceanic ecology and distribution. We attached 204 pop-up satellite archival tags to post-spawned salmon when they migrated to the ocean from seven European areas and maiden North American salmon captured at sea at West Greenland. Individuals migrated further north and east than previously reported and displayed increased diving activity near oceanographic fronts, emphasizing the importance of these regions as feeding areas. The oceanic distribution differed among individuals and populations, but overlapped more between geographically proximate than distant populations. Dissimilarities in distribution likely contribute to variation in growth and survival within and among populations due to spatio-temporal differences in environmental conditions. Climate-induced changes in oceanographic conditions will alter the location of frontal areas and may have stock-specific effects on Atlantic salmon population dynamics, likely having the largest impacts on southern populations.

Fish distribution in a southern Patagonian river invaded by Chinook salmon

This study analysed the spatial–temporal abundance and distribution of exotic Chinook salmon (Onchorynchus tsawytscha) along the shore zone of the Lapataia River in relationship with the presence of non-native brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), and native small puyen (Galaxias maculatus) during the four seasons of the year. These data were used to detect fish patchiness and spatial overlap and related to environmental characteristics to determine the habitat used by each species. Juvenile Chinook salmon was recorded only in spring and summer, showing a highly aggregated spatial distribution pattern. The native small puyen dominated fish assemblages all over the year, except in winter when brook trout showed the highest abundance. The highest overlap was detected between small puyen and Chinook salmon. Chinook salmon distribution was mainly explained by the occurrence of flood plains. Brown trout distribution was highly related to the presence of woody debris, while small puyen and brook trout showed no preferences for any environment. These results provide little evidence for habitat competition between Chinook salmon and the other native and non-native fish species. In contrast, species habitat preferences are likely shaping the current fish distribution.

Large inter-stock differences in catch size-at-age of mature Atlantic salmon observed by using genetic individual origin assignment from catch data.

Genetic individual assignment of river stock of origin of mixed stock catch fish offers a tool to analyze size differences among river stocks. Data on the genetically identified river stock of origin of individual fish from commercial mixed stock catches were used to compare the catch size-at-age of mature Atlantic salmon catch fish (Salmo salar) from different rivers in the Baltic Sea. In this application of genetic mixed stock modeling, individual assignments of the river stock of origin were analyzed together with length- and weight-at-age data for individual catch fish. The use of four genetic stock identification based methods was compared for defining the length distributions of caught mature salmon in different river stocks. The catch data included information on maturing salmon in the northern Baltic Sea over the years 2000–2013. DNA microsatellite data on 17 loci and information on the smoltification age were used to assign spawners to their stock of origin. All of the compared methods for using probabilistic stock of origin data in our case yielded very similar estimates of the final mean length distributions of the stocks. The Bayesian mixture model yielded slightly more conservative estimates than the direct probability method, threshold method, or the modified probability method. The catch size between spawners of a same sex and age from river stocks differed significantly and the differences were large. The mean catch weight of 1-sea-winter old mature males in different rivers varied from 1.9 kg to 2.9 kg, from 5.1 kg to 7.5 kg for 2-sea-winter old males, from 5.0 kg to 7.2 kg for 2-sea-winter old females, and from 8.2 kg to 10.8 kg for 3-sea-winter-old females. The mean size of caught wild salmon spawners in each year-class was on average smaller than that of the hatchery-reared and sea ranched stocks.

Leveraging Delta Smelt Monitoring for Detecting Juvenile Chinook Salmon in the San Francisco Estuary

Monitoring is an essential component in ecosystem management, and leveraging existing data sources for multiple species of interest can be one effective way to enhance information for management agencies. Here, we analyzed juvenile Chinook Salmon (Oncorhynchus tshawytscha) bycatch data that has been collected by the recently established Enhanced Delta Smelt Monitoring program (EDSM), a survey designed to estimate the abundance and distribution of the San Francisco Estuary’s (estuary) endangered Delta Smelt (Hypomesus transpacificus). Two key aspects of the EDSM program distinguish it from other fish surveys in the estuary: a stratified random sampling design and the spatial scale of its sampling effort. We integrated the EDSM data set with other existing surveys in the estuary, and used an occupancy model to assess differences in the probability of detecting Delta Smelt across gear types. We saw no large-scale differences in size selectivity, and while detection probability varied among gear types, cumulative detection probability for EDSM was comparable to other surveys because of the program’s use of replicate tows. Based on our occupancy model and sampling effort in the estuary during spring of 2017 and 2018, we highlighted under-sampled regions that saw improvements in monitoring coverage from EDSM. Our analysis also revealed that each sampling method has its own benefits and constraints. Although the use of random sites with replicates, as conducted by EDSM, can provide more statistically robust abundance estimates relative to traditional methods, the use of fixed stations and simple methods such as beach seining may provide a more cost-effective way to monitor salmon occurrence in certain regions of the estuary. Leveraging the strengths of each survey’s method can enable stronger inferences on salmon abundance and distribution. Careful consideration of these trade-offs is crucial as the management agencies of the estuary continue to adapt and improve their monitoring programs.

Comparing redd distributions of chum and masu salmon in the Kotonihassam River, Hokkaido.

Comparing redd distributions of chum and masu salmon in the Kotonihassam River, Hokkaido.

Factors determining spawning run dynamics and current state of sockeye salmon <i>Oncorhynchus nerka</i> resources in the Kamchatka River

Hydrological regime and morphodynamics of the outlet part of the Kamchatka River, dynamics of mixing zone, patterns of juvenile Pacific salmon distribution and migration in the coastal waters of Kamchatsky Gulf in the zone of operating trap nets were analyzed on the results of complex field works prowided in summer period in 2018–2019; fishing and specifics of sockeye salmon spawning run in the river was described. In the course of analyzing the entire complex of available long-term data, an assessment of the likely impact of some key factors on the dynamics of anadromous migration of sockeye salmon in the Kamchatka River was made; biological statistics of spawners and current state of reproduction of this stock was demonstrated. It is found, that natural environmental factors, neither abiotic nor biotic (including fish health as population internal factor), could not cause disturbance of sockeye salmon spawning run dynamics in the Kamchatka River in recent years. Smoller body size and physiological imperfection of the spawners before the anadromous migration due to effects of high number of pink salmon in recent years are suggested to be the most likely cause of spawning run delay in late sockeye salmon morph. Regime of commercial use of the stock and general increasing pressure on the spawning stock by coastal fisheries are demonstrated to be the strongest outer factors to affect modern state of the resources and sockeye salmon population structure in the Kamchatka River, causing permanent escapement deficiency on spawning grounds in the river basin (first of all in the late morph), and also infact lead to disballance between different subpopulation groups in the composition of the stock. Recommendations in order to provide recovery and sustainable level of the Kamchatka River sockeye salmon stock are given in the perspective of more efficient commercial use of the stock next several years; highlights for further researches are outlined.

Fine-scale spatiotemporal variation in juvenile Chinook Salmon distribution, diet and growth in an oceanographically heterogeneous region

The existence of fine-scale structure in the abiotic and biotic characteristics of pelagic habitats is widely recognized, but the ecological significance of that structure is understudied. Logistical considerations have meant that research on the ecology of commercially and ecologically important marine species generally occurs at relatively coarse spatial and temporal scales. Many populations of Chinook Salmon (Oncorhynchus tshawytscha) in the Northeast Pacific are currently experiencing low productivity. The hypothesis that survival, and hence recruitment, of Chinook Salmon is related to growth early in marine residence has led to intensive research on the trophic ecology of this species during the first year at sea. We employed a small vessel-based methodology to simultaneously characterize fine-scale spatial and temporal variation in physical and biological oceanography, and juvenile Chinook Salmon distribution, size, diet, temperature exposure, and growth from July through October at five sites within the Southern Gulf Islands of the Salish Sea. Densities of zooplankton prey of Chinook Salmon declined to very low levels by the end of the study period. Juvenile Chinook Salmon stomach fullness and growth also declined by early fall while frequency of empty stomachs and importance of fish in diets increased. We found that both oceanographic conditions and trophic ecology of juvenile Chinook Salmon varied among sites only a few (2–23) kilometers apart. Juvenile Chinook Salmon were larger and faster growing at sites where fish (generally Pacific Herring Clupea pallasii) constituted a larger proportion of the diet. Overall, the most important prey of juvenile Chinook Salmon by mass proportion (25.6%) was Pacific Herring; however, only 8.4% of individuals contained C. pallasii. Analysis of co-occurrence of diet items suggested alternate foraging strategies, with some individuals specializing on Pacific Herring while others targeted a variety of small crustacean zooplankton. Juvenile Chinook Salmon which had consumed Pacific Herring had greater mean stomach fullness than those which had not. Predation on Pacific Herring was strongly related to juvenile salmon length, suggesting that age-0 Pacific Herring may have been too large to be consumed by smaller Chinook Salmon. Our results reinforce the importance of the transition to piscivory in the trophic ecology of juvenile Chinook Salmon. Further research is necessary to determine if fine-scale distribution of larger, piscivorous juvenile salmon is linked to the distribution of their forage fish prey and to understand the role of prey to predator size ratios in limiting the ability of juvenile salmon to transition to piscivory.

Acoustic characterization of juvenile Pacific salmon distributions along an eco-engineered seawall

A mobile dual-frequency identification sonar (DIDSON) was used to characterize juvenile Pacific salmon (Oncorhynchus spp.) daytime use of armored and eco-engineered seawall habitats along an urbanized shoreline in Puget Sound, Washington, USA. Eco-engineering included intertidal benches to elevate the seafloor, a textured seawall to provide refuge and encourage invertebrate colonization, and glass blocks in an overhanging sidewalk to increase ambient light. A DIDSON multibeam sonar gave salmon counts twice that of visual surveys, and was thus deemed effective as a mobile sampling tool for small fish (~40-90 mm) and can be advantageous relative to visual methods depending on research goals, habitats, and ambient light levels. Increased salmon presence in the eco-engineered intertidal corridor relative to traditional seawall and pier habitats showed that the combination of increased light, reduced infrastructure (e.g. pier pilings), increased texture, and a shallower seafloor improves habitat function for juvenile salmon. High densities of juvenile salmon along pier ends show that salmon also use alternative migration pathways, with unknown energetic costs and predations risks.