Influence of ocean ecosystem variation on trophic interactions and survival of juvenile coho and Chinook salmon

2014 ◽  
Vol 71 (11) ◽  
pp. 1747-1757 ◽  
Author(s):  
James P. Losee ◽  
Jessica A. Miller ◽  
William T. Peterson ◽  
David J. Teel ◽  
Kym C. Jacobson
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Parasite Community ◽  
Parasite Fauna ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Marine Parasites ◽  
Ocean Ecosystem ◽  
Marine Parasite

The community of trophically transmitted marine parasites of juvenile coho (Oncorhynchus kisutch) and Chinook (Oncorhynchus tshawytscha) salmon across 8 years (2002–2009) was related to indices of physical and biological ocean conditions and adult returns. When the biomass of lipid-poor, southern origin copepods in the coastal ocean was high during juvenile salmon outmigration from fresh water (April–June), yearling coho and Chinook salmon harbored a different trophically transmitted parasite fauna and exhibited lower survival compared with years when the southern copepod biomass was low. As copepods are key intermediate hosts in many marine parasite life cycles, these results support a trophic linkage between the copepod community and salmon prey. Interannual variation in the parasite community was correlated with survival of coho salmon (r = −0.67) measured 1 year later and adult returns of Upper Columbia River summer and fall Chinook salmon (r = −0.94) 3 years from the time of ocean entry.

scholarly journals Consequences of Piscine orthoreovirus genotype 1 (PRV‐1) infections in Chinook salmon ( Oncorhynchus tshawytscha ), coho salmon ( O. kisutch ) and rainbow trout ( O. mykiss )

2020 ◽  
Vol 43 (7) ◽  
pp. 719-728 ◽  
Author(s):  
Maureen K. Purcell ◽  
Rachel L. Powers ◽  
Torunn Taksdal ◽  
Doug McKenney ◽  
Carla M. Conway ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Genotype 1

scholarly journals Geomagnetic field influences upward movement of young Chinook salmon emerging from nests

2018 ◽  
Vol 14 (2) ◽  
pp. 20170752 ◽  
Author(s):  
Nathan F. Putman ◽  
Michelle M. Scanlan ◽  
Amanda M. Pollock ◽  
Joseph P. O'Neil ◽  
Ryan B. Couture ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Chinook Salmon ◽  
Geomagnetic Field ◽  
Oncorhynchus Tshawytscha ◽  
Dimensional Space ◽  
Spatial Scales ◽  
Vertical Component ◽  
Life Cycles ◽  
Upward Movement ◽  
The Magnetic Field

Organisms use a variety of environmental cues to orient their movements in three-dimensional space. Here, we show that the upward movement of young Chinook salmon ( Oncorhynchus tshawytscha ) emerging from gravel nests is influenced by the geomagnetic field. Fish in the ambient geomagnetic field travelled farther upwards through substrate than did fish tested in a field with the vertical component inverted. This suggests that the magnetic field is one of several factors that influences emergence from the gravel, possibly by serving as an orientation cue that helps fish determine which way is up. Moreover, our work indicates that the Oncorhynchus species are sensitive to the magnetic field throughout their life cycles, and that it guides their movements across a range of spatial scales and habitats.

Changes in the Average Size and Average Age of Pacific Salmon

1981 ◽  
Vol 38 (12) ◽  
pp. 1636-1656 ◽  
Author(s):  
W. E. Ricker
Keyword(s):  
Growth Rate ◽  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Gill Nets ◽  
Growing Seasons ◽  
Mean Size ◽  
Average Size

Of the five species of Pacific salmon in British Columbia, chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) are harvested during their growing seasons, while pink salmon (O. gorbuscha), chum salmon (O. keta), and sockeye salmon (O. nerka) are taken only after practically all of their growth is completed. The size of the fish caught, of all species, has decreased, but to different degrees and over different time periods, and for the most part this results from a size decrease in the population. These decreases do not exhibit significant correlations with available ocean temperature or salinity series, except that for sockeye lower temperature is associated with larger size. Chinook salmon have decreased greatly in both size and age since the 1920s, most importantly because nonmaturing individuals are taken by the troll fishery; hence individuals that mature at older ages are harvested more intensively, which decreases the percentage of older ones available both directly and cumulatively because the spawners include an excess of younger fish. Other species have decreased in size principally since 1950, when the change to payment by the pound rather than by the piece made it profitable for the gill-netters to harvest more of the larger fish. Cohos and pinks exhibit the greatest decreases, these being almost entirely a cumulative genetic effect caused by commercial trolls and gill nets removing fish of larger than average size. However, cohos reared in the Strait of Georgia have not decreased in size, possibly because sport trolling has different selection characteristics or because of the increase in the hatchery-reared component of the catch. The mean size of chum and sockeye salmon caught has changed much less than that of the other species. Chums have the additional peculiarity that gill nets tend to take smaller individuals than seines do and that their mean age has increased, at least between 1957 and 1972. That overall mean size has nevertheless decreased somewhat may be related to the fact that younger-maturing individuals grow much faster than older-maturing ones; hence excess removal of the smaller younger fish tends to depress growth rate. Among sockeye the decrease in size has apparently been retarded by an increase in growth rate related to the gradual cooling of the ocean since 1940. However, selection has had two important effects: an increase in the percentage of age-3 "jacks" in some stocks, these being little harvested, and an increase in the difference in size between sockeye having three and four ocean growing seasons, respectively.Key words: Pacific salmon, age changes, size changes, fishery, environment, selection, heritability

Production of germline transgenic Pacific salmonids with dramatically increased growth performance

1995 ◽  
Vol 52 (7) ◽  
pp. 1376-1384 ◽  
Author(s):  
Robert H. Devlin ◽  
Timothy Y. Yesaki ◽  
Edward M. Donaldson ◽  
Shao Jun Du ◽  
Choy-Leong Hew
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Cutthroat Trout ◽  
Transgenic Fish ◽  
Somatic Tissue ◽  
Growth Enhancement ◽  
Gene Construct ◽  
Average Size

Transgenic Pacific salmon have been produced by microinjection of a DNA construct consisting of chinook salmon (Oncorhynchus tshawytscha) growth hormone sequences driven by an ocean pout (Macrozoarces americanus) antifreeze protein promoter. This construct was retained in approximately 4% of fish derived from injected eggs, and resulted in dramatic enhancement of growth relative to controls. For coho salmon (O. kisutch) at 15 months of age, the average size of transgenic fish was more than 10-fold that of controls, with the largest fish more than 30-fold larger than nontransgenic siblings. Dramatic growth enhancement was also observed in transgenic rainbow trout (O. mykiss), cutthroat trout (O. clarki), and chinook salmon using this same gene construct. Transgenic coho salmon underwent precocious parr–smolt transformation during their first fall, approximately 6 months in advance of their nontransgenic siblings. At 2 years of age, five male transgenic coho salmon became sexually mature, and four of these transmitted the gene construct to sperm, the negative fish being transgenic in blood but not fin tissue. These results show that while some fish are mosaic for the gene construct in different tissues, most are transgenic in both germline and somatic tissue.

scholarly journals The Entrainment and Screening of Returning and Postspawning Adult Salmonids at Irrigation Canals of the Umatilla River, Oregon

2018 ◽  
Vol 9 (1) ◽  
pp. 285-295
Author(s):  
William G. Simpson
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Juvenile Fish ◽  
Irrigation Canal ◽  
Irrigation Canals ◽  
Water Currents ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Passive Integrated Transponders ◽  
Direction Of Movement

Abstract Anadromous salmonids can be vulnerable to entrainment at diversion intake structures on streams, effectively trapping fish in irrigation canals and removing them from a population. Currently little is known about how the differences in timing and direction of movement among adult salmonids contribute to their risk of entrainment and how successful they are at escaping irrigation canals. Potential routes of escape include passing against water currents and through the headgate of an irrigation canal intake or by navigating through screen and bypass infrastructure primarily designed to return juvenile fish to a stream. In this study, passive integrated transponders (PIT tags) were used to track the movement of adult Chinook Salmon Oncorhynchus tshawytscha (n = 573), Coho Salmon Oncorhynchus kisutch (n = 39), and anadromous Rainbow Trout Oncorhynchus mykiss (steelhead, n = 853) as they entered areas of the Umatilla River basin (Oregon) with irrigation canals and as they attempted to escape irrigation canals after entrainment. Although adult steelhead and spring Chinook Salmon often encountered diversions at similar times, the vast majority of entrained adults were steelhead (94%). Between 2% and 8% of adult steelhead observed entering the area were entrained. The entrainment of steelhead was strongly associated with downstream movements and Umatilla River discharge below 40 m3/s. Many downstream-moving steelhead were postspawning fish (kelts). As a result, vulnerability of anadromous adults to entrainment differed by species due to the direction of their movements and how these movements coincide with canal operations and river flows. It is unlikely that the screened irrigation canals acted as an ecological sink; the majority of adult salmonids approached the screen and bypass infrastructure (≥88%) and later river detection confirmed that many had used that infrastructure to return to the river (≥47%). However, half of steelhead appeared to experience bypass delays at fish screens. Adult steelhead that approached the canal headgate after becoming trapped in the canal did not successfully return to the Umatilla River using this route. Unscreened irrigation canals elsewhere may disproportionally trap downstream-moving steelhead, like postspawning kelts, due to their propensity for entrainment and their difficulties escaping through the water intakes of irrigation canals. In streams with anadromous salmonids, fish screen and bypass infrastructure primarily designed to eliminate the permanent entrainment of juvenile fish can also prevent the removal of adult fish that may reproductively contribute to the population.

Influence of the transmission of parasites from prey fishes on the composition of the parasite community of a predatory fish

1995 ◽  
Vol 52 (S1) ◽  
pp. 233-245 ◽  
Author(s):  
E. Tellervo Valtonen ◽  
Markku Julkunen
Keyword(s):  
Parasite Community ◽  
Life Cycles ◽  
Predatory Fish ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Complex Life Cycles ◽  
Lota Lota ◽  
Gymnocephalus Cernuus ◽  
Adult Trematode ◽  
Bothnian Bay

Helminth parasites and diet of seven freshwater fishes (Lota lota and six common prey species) from the Bothnian Bay, Baltic Sea, were studied monthly or bimonthly during 1978. Twenty-one of the 32 parasites with complex life cycles were shared between Lota lota and its prey fishes and are thus transmissible from prey to predator. Gymnocephalus cernuus and L. lota had the greatest number of shared species (13). Larval and adult cestodes, nematodes, and acanthocephalans could re-establish in the predator, but only one adult trematode was capable of this transition. Infracommunity species diversity was highest in L. lota (eH′ = 3.54), which also had the most species (24), the highest mean number of species and individuals of a given species per fish (6.3 and 62, respectively), and the greatest number of worms in one fish (520). Variety of diet was key in determining exposure to parasite species. However, most specificity finally determined if a given parasite could establish and mature. No ecologically explicable suites of parasites were found in any fish species, except in a few cases where parasites used related intermediate hosts. However, the composition of these suites was not retained in the predator. Unlike in L. lota, important parasites of prey fishes were typically specialists.

The Harmful Phytoplankter Chaetoceros concavicornis Causes High Mortalities and Leucopenia in Chinook Salmon (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch)

1994 ◽  
Vol 51 (11) ◽  
pp. 2493-2500 ◽  
Author(s):  
C. Z. Yang ◽  
L. J. Albright
Keyword(s):  
Immune System ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Goblet Cells ◽  
Mortality Rates

Chaetoceros concavicornis is a harmful phytoplankter that occurs in many temperate coastal seawaters and can cause fin fish mortalities when present at concentrations as low as 5 cells∙mL−1. At even lower concentrations, this diatom can stress salmonids to such an extent that they may express a disease to which they are most prone at the time of C. concavicornis exposure. We report mortality rates of coho salmon (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) exposed to different concentrations of C. concavicornis. Our data indicate that in the presence of harmful concentrations of C. concavicornis, blood hematocrit and erythrocyte, glucose, and lactate concentrations of yearling chinook salmon (O. tshawytscha) increase. The microridges of the primary lamellae decreased in prominence in the presence of harmful concentrations of this phytoplankter, while the goblet cells became more prominent and more numerous. Neutrophil, lymphocyte, and thrombocyte concentrations in the blood became depleted. These data suggest that suppression of a portion of the Chinook's immune system is occurring which may partially explain the earlier observation that salmonids cultured in the presence of harmful C. concavicornis phytoplankton became more susceptible to disease, including Vibrio infections.

Fertilization of Chinook and Coho Salmon Eggs with Cryo-Preserved Sperm

1971 ◽  
Vol 28 (5) ◽  
pp. 745-748 ◽  
Author(s):  
A. G. Ott ◽  
H. F. Horton
Keyword(s):  
Dimethyl Sulfoxide ◽  
Liquid Nitrogen ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Salmon Eggs ◽  
Viable Sperm

Techniques were developed that resulted in the fertilization of fresh eggs of spring chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) with sperm frozen 7 days in liquid nitrogen (−196 C). Maximum fertilities obtained were 38 and 79%, respectively. Best results for coho salmon were achieved when mannitol and dimethyl sulfoxide were included in the extender, and when no time was allowed for equilibration of the fresh sperm to the extender. This is the first success reported in preserving viable sperm of these two species at subfreezing temperatures.

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