Pink Salmon Oncorhynchus Gorbuscha Research Articles

Results of quantitative counting for downstream juveniles of pink salmon Oncorhynchus gorbuscha in the Malaya Khuzi River (north-east of Sakhalin Island) in 2023

Results of quantitative counting for downstream juveniles of pink salmon Oncorhynchus gorbuscha in the Malaya Khuzi River (north-east of Sakhalin Island) in 2023

Results of fishery for pink salmon Oncorhynchus gorbuscha in Primorye Region and hydrometeorological conditions in the Japan Sea in 2023

Results of fishery for pink salmon Oncorhynchus gorbuscha in Primorye Region and hydrometeorological conditions in the Japan Sea in 2023

Changes in the Activity of Na+/K+-ATPase and in the Lipid Composition of the Gills of Pink Salmon Oncorhynchus gorbuscha (Salmonidae) from the White Sea in the Course of Spawning Migration

Changes in the Activity of Na+/K+-ATPase and in the Lipid Composition of the Gills of Pink Salmon Oncorhynchus gorbuscha (Salmonidae) from the White Sea in the Course of Spawning Migration

Pink salmon Oncorhynchus gorbuscha in the basins of large rivers of the Krasnoyarsk territory: history of introduction, biological characteristics

The history and geography of the distribution of pink salmon Oncorhynchus gorbuscha in water bodies of the Taimyr Peninsula (Krasnoyarsk territory) is presented. Temperature conditions for spawning are indicated. The possible influence of pink salmon as an alien species for the fauna of Siberian rivers is discussed.

Genetic identification of juvenile pink salmon Oncorhynchus gorbuscha (Walbaum) of the odd-year reproduction line on results of restriction analysis of mitochondrial DNA and analysis of single-nucleotide polymorphism

Data on the regional composition of mixed marine aggregations of juvenile pink salmon during postcatadromous migrations in the basin of the Sea of Okhotsk in 2022 are demonstrated. A high probability of a significant predominance is revealed for pink salmon spawning returns 2023 of the northern stock complex compared to the southern ones. Identification estimates for juvenile fish obtained from RFLP analysis of mtDNA and analysis of allelic variability of SNP loci are compared to the values of actual regional catches and spawning returns. Close correspondence between the calculated estimates and actual data on the results of the 2023 fishing season was noted. Forecast about predominance of pink salmon of the northern stock complex, as well as about atypically low proportion of fish from water bodies of Iturup Island is fully confirmed. The estimates for Sakhalin Island and the southern part of the continental coast of the Sea of Okhotsk are close to the actual catch.

Biennial patterns in Alaskan sockeye salmon ocean growth are associated with pink salmon abundance in the Gulf of Alaska and the Bering Sea

Abstract 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.

Invasion status of hatchery-origin pink salmon in an unstocked river at the Shiretoko World Natural Heritage Site in northern Japan.

Hatchery fish and their offspring (including hatchery-wild hybrids) have lower reproductive success than wild fish. Thus, the straying of hatchery fish may negatively impact wild populations, depending on the number of wild salmon returning and hatchery strays. We investigated the straying status of hatchery-origin pink salmon (Oncorhynchus gorbuscha), which have a higher straying rate than other salmonids, in an unstocked river at the Shiretoko World Natural Heritage Site, Japan. The hatchery strays accounted for 40.0% and 19.0% of the total samples in 2021 and 2022, respectively. These results indicate that hatchery pink salmon have invaded unstocked rivers and potentially genetically affect wild populations.

Salmon louse labial gland enzymes: implications for host settlement and immune modulation.

Salmon louse (Lepeophtheirus salmonis) is a skin- and blood-feeding ectoparasite, infesting salmonids. While feeding, labial gland proteins from the salmon louse may be deposited on the Atlantic salmon (Salmo salar) skin. Previously characterized labial gland proteins are involved in anti-coagulation and may contribute to inhibiting Atlantic salmon from mounting a sufficient immune response against the ectoparasite. As labial gland proteins seem to be important in the host-parasite interaction, we have, therefore, identified and characterized ten enzymes localized to the labial gland. They are a large group of astacins named L. salmonis labial gland astacin 1-8 (LsLGA 1-8), one serine protease named L. salmonis labial gland serine protease 1 (LsLGSP1), and one apyrase named L. salmonis labial gland apyrase 1 (LsLGAp1). Protein domain predictions showed that LsLGA proteins all have N-terminal ShK domains, which may bind to potassium channels targeting the astacins to its substrate. LsLGA1 and -4 are, in addition, expressed in another gland type, whose secrete also meets the host-parasite interface. This suggests that LsLGA proteins may have an anti-microbial function and may prevent secondary infections in the wounds. LsLGAp1 is predicted to hydrolyze ATP or AMP and is, thereby, suggested to have an immune dampening function. In a knockdown study targeting LsLGSP1, a significant increase in IL-8 and MMP13 at the skin infestation site was seen under LsLGSP1 knockdown salmon louse compared to the control, suggesting that LsLGSP1 may have an anti-inflammatory effect. Moreover, most of the identified labial gland proteins are expressed in mature copepodids prior to host settlement, are not regulated by starvation, and are expressed at similar or higher levels in lice infesting the salmon louse-resistant pink salmon (Oncorhynchus gorbuscha). This study, thereby, emphasizes the importance of labial gland proteins for host settlement and their immune dampening function. This work can further contribute to anti-salmon louse treatment such as vaccine development, functional feed, or gene-edited salmon louse-resistant Atlantic salmon.

Pink salmon productivity is driven by catchment hydrogeomorphology and can decline under a changing climate

Abstract Increased flood magnitude and frequency due to climate change can reduce the population productivity of organisms such as amphibian and fish species in river and stream systems; therefore, conserving habitats that maintain high productivity under such conditions is crucial. Here, we examined the relationship between the freshwater productivity of anadromous salmonids (measured as fry migrating to the ocean per spawner) and catchment hydrogeomorphology and identified the characteristics of rivers and streams that are prone to flood disturbance. We surveyed the spawner abundance and number of fry of pink salmon (Oncorhynchus gorbuscha) and measured environmental factors, including the average catchment slope and stream power, as characteristics of hydrogeomorphology, in 10 streams in the Shiretoko Peninsula, northern Japan. We then used generalised linear mixed models to predict the freshwater productivity of pink salmon populations in each catchment across the study region under current and future climatic conditions. The productivity of pink salmon in the study region differed among the sampled catchments and was negatively affected by the average catchment slope, stream power, and maximum daily precipitation averaged over the catchment. Namely, flood disturbance reduced the freshwater productivity of pink salmon, and salmon productivity in individual catchments was explained by catchment hydrogeomorphology. The predicted future productivity with increased precipitation was also lower than the current productivity. Our approach can be applied to other salmonids that have similar spawning behaviour to pink salmon. Highly productive catchments under the future climatic conditions predicted by the present study should be prioritised for conservation to ensure a sustainable salmonid population.

Active feeding of downstream migrating juvenile pink salmon (Oncorhynchus gorbuscha) revealed in a large Barents Sea river using diet and stable isotope analysis.

The recent, rapid spreading of non-native pink salmon Oncorhynchus gorbuscha in the North Atlantic area has raised concerns about their possible negative impacts on native salmonid species. Potential interactions include competition for food resources during the short freshwater phase of juvenile O. gorbuscha, but little is known about their feeding behavior in the newly occupied North Atlantic rivers. Using stable isotope and stomach content analyses, patterns of freshwater feeding of non-native O. gorbuscha fry were studied in a large Fennoscandian river, the Teno, that discharges to the Barents Sea. Changes in stable isotope values (δ13 C, δ15 N, δ34 S) and stomach contents from the period of emergence (April to mid-May) to estuarine entry (late May/June) were examined and provided both temporally integrated and short-term indicators of freshwater feeding dependency. In addition, the occurrence of juvenile O. gorbuscha and changes in their length and weight during their emergence/migration period were investigated. Juvenile O. gorbuscha were at the spawning grounds from April through to mid-May with abundance peaking in mid-May. Fish moved to the estuary by late May and their abundance decreased toward June, and their body size increased concurrently. Stomach analyses indicated no feeding activity in April-early May in the spawning areas, but the stomach fullness indices increased markedly in fish sampled in the estuary in May and June. The most important prey items in stomachs were Chironomidae and Ephemeroptera larvae. Significant changes in all analysed stable isotopes were detected among sample periods, with a peak in mid-May and June showing significantly lower values than other sample periods. A change from the higher values reflective of parental marine feeding to the lower values reflective of freshwater feeding indicated active in-river feeding by juveniles during the study period. The documented active freshwater feeding of non-native juvenile O. gorbuscha suggests potential resource competition with native fluvial fishes, particularly salmonids.

Influence of marine habitat on microplastic prevalence in forage fish and salmon in the Salish Sea

Microplastics are increasingly prevalent in marine systems and are a growing concern as a marine pollutant and contaminant with consequences for high trophic level consumers, including humans. Given evidence that links plastics to degraded ecosystem functioning and organismal health, there is increased interest in understanding the prevalence, fate and consequences of marine plastics. Microplastics contain and absorb harmful chemicals which may serve as endocrine disruptors and have negative implications for growth, reproductive health, and longevity. To expand current knowledge on microplastics in coastal marine ecosystems and the potential for biomagnification in marine food webs, we conducted stomach analyses of microplastics in Pacific salmon (Oncorhynchus spp.) and Pacific sand lance (Ammodytes personatus), an important prey for salmon. Prevalence of microplastics was substantial; 77 % of all salmon and 25 % of all sand lance stomachs contained at least one microplastic. Fish were sampled at multiple sites throughout the inland Salish Sea, including beaches and sediment bedforms for Pacific sand lance and open-water pelagic habitat for Pacific salmon. Pacific sand lance sampled at beach sites had more microplastics compared to those sampled in subtidal sediments and there were more plastics in sand lance at a protected beach site as compared to an exposed beach site. Prevalence of plastics in salmon differed according to species and included analyses of pink salmon (Oncorhynchus gorbuscha), Chinook (Oncorhynchus tshawytscha), and Coho salmon (Oncorhynchus kisutch); plastics were predominantly fibers in all species, though there were relatively higher rates of ingestion of films and particles in Chinook. Comparisons between plastic concentrations and stomach fullness indicated a slight negative trend, suggesting that plastics may be retained. Further investigation is needed to develop a more thorough understanding of the prevalence and fate of microplastics in coastal marine systems such as the Salish Sea, their concentration within marine food webs, and the implications for species targeted in fisheries.

On Widening the Hybrid Zone for Chars of Genus Salvelinus, Kundscha S. leucomaenis and Northern Dolly Varden S. malma (Salmonidae), in Rivers of Kamchatka Peninsula

The data on widening the zone for hybridization between the chars of the genus Salvelinus, kundscha S. leucomaenis and northern dolly varden S. malma (Salmonidae), in rivers of the Kamchatka Peninsula are reported. If the hybrids between the kundscha and the northern dolly varden could be previously observed only in the Utkholok River in the northwest of the peninsula, the mass hybridization between these species have occurred in two more nearby rivers, the Kvachina and Snatolveem Rivers since 2009. A microsatellite analysis has shown that hybrid specimens are characterized by intermediate values for allelic diversity, when compared to that in the representatives of parental species, while the mean expected heterozygosity values for hybrids are higher than that in Dolly Varden and kundscha fish. The analysis results for maternal inheritance in hybrid specimens from the Kvachina River coincide with that obtained in the surveys previously performed in the Utkholok River. Thus, the same haplotype specific for the kundscha fish was revealed in all the hybrid specimens, which can indicate that the hybrids originate from kundscha females and Dolly Varden males. The appearance and coloration of kundscha × northern dolly varden hybrids in the Kvachina and Snatolveem Rivers are similar to that in the specimens in the Utkholok River. Rather similar chacteristics of hybrid specimens in all three rivers can give reason to consider that a mechanism of their occurrence in the Kvachina and Snatolveem Rivers is simalr to that in the Utkholok River, since the kundscha eggs are inseminated by the Dolly Varden dwarf males. The increased local biological production of rivers due to increased sizes of spawning stocks of pink salmon Oncorhynchus gorbuscha along with large-scale climate changes in the North Pacific are considered as a possible cause of disturbances of isolation between species. It is quite probable that these two factors have contributed to improving the environmental conditions for fattening the Dolly Varden fish in the freshwater phase of their life cycle and, as a resultl of this process, increasing the number of Dolly Varden male fish matuaring in the river.

Evidence of successful recruitment of non-native pink salmon Oncorhynchus gorbuscha in Iceland.

In mid-May 2022, pink salmon Oncorhynchus gorbuscha smolts were caught in the rivers Botnsá, Grímsá, and Langá in Iceland. This observation provides the first evidence of successful spawning and the completion of the freshwater phase of the life cycle in Icelandic rivers. It is the most western record of O. gorbuscha smolts in Europe, further west than Russia, Norway, and the UK. Smolts originating from Iceland potentially support the recruitment of this species in the North Atlantic and may lead to the establishment of a self-sustaining population in Iceland.

Tidal gradients, fine-scale homing and a potential cryptic ecotype of wild spawning pink salmon (Oncorhynchus gorbuscha).

The homing behaviour of salmon is a remarkable natural phenomenon, critical for shaping the ecology and evolution of populations yet the spatial scale at which it occurs is poorly understood. This study investigated the spatial scale and mechanisms driving homing as depicted by spawning site-choice behaviour in pink salmon (Oncorhynchus gorbuscha) in Prince William Sound, Alaska. Molecular pedigree analyses of over 30,000 adult spawners in four streams revealed that pink salmon exhibit fine-scale site fidelity within a stream, returning to within <100 m of their parents. Homing behaviours were driven in part by a salinity gradient between intertidal and freshwater environments, with individuals incubated in freshwater environments more than twice as likely to spawn upstream of tidal influence than those incubated in the intertidal. Our findings challenge the traditional view that pink salmon populations are genetically and phenotypically homogenous due to their short freshwater residency as juveniles and high rates of dispersal as returning adults (i.e. straying). This study has important implications for rates of inbreeding, local adaptation and gene flow within populations, and is particularly relevant to the management of salmon hatcheries, given the high incidence of hatchery-origin pink salmon, reared in freshwater hatchery environments, that stray into wild populations of Prince William Sound.

Gametogenesis of pacific salmon. 1. Pink salmon &lt;i&gt;Oncorhynchus gorbuscha&lt;/i&gt;

Cited information on gametogenesis of pink salmon Oncorhynchus gorbuscha Walbaum is summarized. Periods of indifferent development and sex differentiation are considered, development of the testes and ovaries is traced, and the fertility formation is analyzed. Regularities of sex reversion, unique for salmonids, and evolutionarily acquired specific features of oogenesis associated with a short life cycle are noted.

Marine diets of anadromous Arctic char (Salvelinus alpinus) and pink salmon (Oncorhynchus gorbuscha) in Svalbard, Norway

During summer, native anadromous Arctic char (Salvelinus alpinus) and the alien species pink salmon (Oncorhynchus gorbuscha) now coexist in marine environments in Svalbard, following the introduction of the latter in the Barents Region. To investigate potential dietary competition between these two salmonid species, stomach contents from Arctic char (n = 301) and pink salmon (n = 28) were sampled from different areas within the archipelago. The most important prey in terms of biomass for both salmonid species were amphipods; Themisto libellula (B = 26.0%) for Arctic char and Onisimus litoralis (B = 35.0%) for pink salmon. Pianka’s niche overlap revealed that dietary overlap between the two species was moderately high (Oobs = 0.59); both species had strong associations with intertidal invertebrates in areas where direct comparisons were possible (Kongsfjorden/Krossfjorden). However, both salmonid species did also eat some fish, with Arctic char consuming more offshore pelagic fish, while the small number of fish eaten by pink salmon were primarily coastal demersal fish species. Arctic char was a more generalist feeder, while pink salmon was more of a dietary specialist. Furthermore, the diet composition of the Arctic char consisted of 32.9% Atlantic prey while the pink salmon, surprisingly, ate only Arctic species, likely due to their tightly coastal feeding habits. Even though the sample size for pink salmon was low, this study contributes new insights into salmonid diets in Svalbard and the potential for introduced species to compete with native Arctic endemics, particularly in the expected warmer Arctic of the future.

Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods

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).

Proteins journey-from marine to freshwater ecosystem: blood plasma proteomic profiles of pink salmon Oncorhynchus gorbuscha Walbaum, 1792 during spawning migration.

The pink salmon (Oncorhynchus gorbuscha) is a commercial anadromous fish species of the family Salmonidae. This species has a 2-year life cycle that distinguishes it from other salmonids. It includes the spawning migration from marine to freshwater environments, accompanied by significant physiological and biochemical adaptive changes in the body. This study reveals and describes variability in the blood plasma proteomes of female and male pink salmon collected from three biotopes-marine, estuarine and riverine-that the fish pass through in spawning migration. Identification and comparative analysis of blood plasma protein profiles were performed using proteomics and bioinformatic approaches. The blood proteomes of female and male spawners collected from different biotopes were qualitatively and quantitatively distinguished. Females differed primarily in proteins associated with reproductive system development (certain vitellogenin and choriogenin), lipid transport (fatty acid binding protein) and energy production (fructose 1,6-bisphosphatase), and males in proteins involved in blood coagulation (fibrinogen), immune response (lectins) and reproductive processes (vitellogenin). Differentially expressed sex-specific proteins were implicated in proteolysis (aminopeptidases), platelet activation (β- and γ-chain fibrinogen), cell growth and differentiation (a protein containing the TGF_BETA_2 domain) and lipid transport processes (vitellogenin and apolipoprotein). The results are of both fundamental and practical importance, adding to existing knowledge of the biochemical adaptations to spawning of pink salmon, a representative of economically important migratory fish species.

Factors Determining the Replenishment of Pink Salmon Oncorhynchus gorbuscha (Salmonidae) on Iturup Island

Based on the data on the abundance of 53 generations of pink salmon Oncorhynchus gorbuscha of Iturup Island (spawners on spawning grounds, downstream migrating juveniles and the return of mature fish), a model describing the dependence of the abundance of mature pink salmon offspring on the initial abundance of generations and the effect of external factors was constructed using nonlinear regression analysis. The model explains about 80% of the replenishment variability, and it depends more on the effect of external factors in the freshwater period of life. The variability of replenishment is most closely related to factors related to the hydrological regime of rivers. The dependence of replenishment on the abundance of juveniles migrating downstream from spawning grounds, described by the dome-shaped curve, indicates the limiting effect of density factors on the formation of the abundance of pink salmon during the marine period of life. At the same time, a statistically significant effect of the abundance of juveniles released from fish hatcheries on the dynamics of the replenishment was not found.

Effects of Salinity on Lipid Composition in Juvenile Pinc Salmon Oncorhynchus gorbuscha (Salmonidae)

Lipid and fatty acid modifications induced by the effects of various salinity patterns on the juvenile pink salmon Oncorhynchus gorbuscha (the Olkhovka River and the White Sea) within the experiment have been revealed. Concentrations of steroids, saturated fatty acids, and signaling molecules such as phospholipids (phosphatidylserine and phosphatidylinositol) and arachidonic acid under the hyperosmotic stress-related effects (keeping the fish for 1 h in the seawater after the time of transfer from the freswater) tend to increase. Decreases in phosphatidylcholine and n-6 saturated, monounsaturated, and polyunsaturated fatty acids are recorded in the juvenile pink salmon fish kept for 24 h in the seawater after the time of transfer them from the freswater, while the levels of phosphatidylethanolamine and n-3 polyunsaturated fatty acids (especially eicosapentaenoic and docosahexaenoic acids), on the contrary, tend to rise significantly. Lipid composition modifications in the juvenile pink salmon fish kept under the hypoosmotic stress conditions (24 h in freshwater after 24 h in seawater) induce stabilization of functioning the cell membrane structure, since the levels of bioeffectors including phosphatidylserine, phosphatidylinositol, and arachidonic, eicosapentaenoic, and docosahexaenoic acids tend to decrease. A reduced amount of lipids (triacylglycerols) stored as an energy reserve is shown for all the experimental fish groups. The outcomes indicate the high levels of adaptive potential of the juvenile pink salmon fish kept under the effects of abrupt salinity change in the water environments and their readiness for downstream migration not long before leaving the nests.