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.

Protandry in Pacific salmon

2000 ◽  
Vol 57 (6) ◽  
pp. 1252-1257 ◽  
Author(s):  
Yolanda Morbey
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Statistical Procedure ◽  
Timing Data ◽  
Mating Opportunities ◽  
Gender Specific ◽  
Specific Timing

Protandry, the earlier arrival of males to the spawning grounds than females, has been reported in several studies of Pacific salmon (Oncorhynchus spp.). However, the reasons for protandry in salmon are poorly understood and little is known about how protandry varies among and within populations. In this study, protandry was quantified in a total of 105 years using gender-specific timing data from seven populations (one for pink salmon (O. gorbuscha), three for coho salmon (O. kisutch), two for sockeye salmon (O. nerka), and one for chinook salmon (O. tshawytscha)). Using a novel statistical procedure, protandry was found to be significant in 90% of the years and in all populations. Protandry may be part of the males' strategy to maximize mating opportunities and may facilitate mate choice by females.

Effect of incubation temperature on the development of five species of Pacific salmon (Oncorhynchus) embryos and alevins

1988 ◽  
Vol 66 (1) ◽  
pp. 266-273 ◽  
Author(s):  
C. B. Murray ◽  
J. D. McPhail
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Incubation Temperature ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Embryo Survival ◽  
Salmon Fry ◽  
Incubation Temperatures

Embryo and alevin survival, time to hatching and emergence, and alevin and fry size of five species of Pacific salmon (Oncorhynchus) were observed at five incubation temperatures (2, 5, 8, 11, and 14 °C). No pink (Oncorhynchus gorbuscha) or chum (O. keta) salmon embryos survived to hatching at 2 °C. Coho (O. kisutch) and sockeye (O. nerka) salmon had higher embryo survival at 2 °C than chinook (O. tschawytscha) salmon. At 14 °C, chum, pink, and chinook salmon had higher embryo survival than coho or sockeye salmon. In all species, peaks of embryo mortality occurred at specific developmental stages (completion of epiboly, eye pigmentation, and hatching). Alevin survival to emergence was high for all species, except for coho and pink salmon at 14 °C. Hatching and emergence time varied inversely with incubation temperature, but coho salmon hatched and emerged sooner at all temperatures than the other species. Coho and sockeye salmon alevins were larger at 2 °C, pink, chum, and chinook salmon alevins were larger at 5 and 8 °C. Coho salmon fry were larger at 2 °C, chinook and chum salmon fry were larger at 5 °C, and sockeye and pink salmon fry were larger at 8 °C. High incubation temperatures reduced fry size in all species. Each species of Pacific salmon appears to be adapted to different spawning times and temperatures, and thus indirectly to specific incubation temperatures, to ensure maximum survival and size and to maintain emergence at the most favorable time each year.

Changes in body size of Canadian Pacific salmon over six decades

2017 ◽  
Vol 74 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Kyla M. Jeffrey ◽  
Isabelle M. Côté ◽  
James R. Irvine ◽  
John D. Reynolds
Keyword(s):  
Body Size ◽  
Sockeye Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Southern Oscillation ◽  
Rapid Change ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Evolutionary Response

Body size can sometimes change rapidly as an evolutionary response to selection or as a phenotypic response to changes in environmental conditions. Here, we revisit a classic case of rapid change in body size of five species of Pacific salmon (Oncorhynchus spp.) caught in Canadian waters, with a six-decade analysis (1951–2012). Declines in size at maturity of up to 3 kg in Chinook (Oncorhynchus tshawytscha) and 1 kg in coho salmon (Oncorhynchus kisutch) during the 1950s and 1960s were later reversed to match or exceed earlier sizes. In contrast, there has been little change in sockeye salmon (Oncorhynchus nerka) sizes and initial declines in pink (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) sizes have halted. Biomass of competing salmon species contributed to changes in size of all five species, and ocean conditions, as reflected by the North Pacific Gyre Oscillation and the Multivariate ENSO (El Niño – Southern Oscillation) indices, explained variation in four of the species. While we have identified a role of climate and density dependence in driving salmon body size, any additional influence of fisheries remains unclear.

Downstream migrations of juvenile Pacific salmon (Oncorhynchus spp.) in a glacial transboundary river

1997 ◽  
Vol 54 (12) ◽  
pp. 2837-2846 ◽  
Author(s):  
Michael L Murphy ◽  
K V Koski ◽  
J Mitchel Lorenz ◽  
John F Thedinga
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Transboundary Rivers ◽  
Delayed Entry ◽  
Transboundary River ◽  
Spawning Areas ◽  
Seventh Order ◽  
Juvenile Pacific Salmon

Migrations of juvenile Pacific salmon (Oncorhynchus spp.) in the glacial Taku River (seventh order) were studied to assess movement from upriver spawning areas (in British Columbia) into lower-river rearing areas (in Alaska). Differences between fyke-net catches in the river and seine catches in the river's estuary indicated that many downstream migrants remained in the lower river instead of migrating to sea. In particular, age-0 coho salmon (O. kisutch) and chinook salmon (O. tshawytscha) moved downriver from May to November but were not caught in the estuary. Age-0 sockeye salmon (O. nerka), coho presmolts, and other groups delayed entry into the estuary after moving downriver. We tagged groups of juvenile coho (ages 0-2) from the fyke net with coded-wire to determine when they left the river. One-third of all tags recovered from sport and commercial fisheries occurred 2-3 years later, showing that many coho remained in fresh water for 1-2 years after moving to the lower river. Lower-river areas of large glacial rivers like the Taku River can provide essential rearing habitat for juvenile salmon spawned upriver and are important to consider in integrated whole-river management of transboundary rivers.

Levels of Constituents of Glycoproteins in the Sera of Pacific Salmon

1971 ◽  
Vol 28 (8) ◽  
pp. 1173-1179 ◽  
Author(s):  
M. D. Qureshi ◽  
R. V. Hledin ◽  
P. A. Anastassiadis ◽  
W. E. Vanstone
Keyword(s):  
Sialic Acid ◽  
Protein Content ◽  
Chinook Salmon ◽  
Bovine Serum ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Nerka ◽  
Limited Extent ◽  
Carbohydrate Complex

The levels of hexosamine, sialic acid, fucose, and protein in serum of sockeye salmon (Oncorhynchus nerka) and, to a limited extent, in sera of coho salmon (O. kisutch) and chinook salmon (O. tshawytscha) at two reproductive stages, were determined. Hexosamine, sialic acid, fucose, hexose, seromucoid, and protein content of sexually maturing (early) and mature (spawning) sockeye salmon were studied and a comparison was attempted with the corresponding composition of bovine serum. Content of the above serum constituents was lower in spawning than in maturing populations. Protein content was much less, hexosamine a little less, and sialic acid higher, in the sera of sockeye salmon than in bovine serum. The protein–carbohydrate complex of serum appeared to contain more hexosamine and much more sialic acid than the protein–carbohydrate complex of bovine serum. Furthermore, the sialic acid-to-hexosamine ratio was much higher in sera of salmon than in bovine serum. Some other sex and reproductive stage differences were detected and reported.

Dispersal and productivity of Chinook (Oncorhynchus tshawytscha) and coho (Oncorhynchus kisutch) salmon colonizing newly accessible habitat

2015 ◽  
Vol 72 (3) ◽  
pp. 454-465 ◽  
Author(s):  
Joseph H. Anderson ◽  
Paul L. Faulds ◽  
Karl D. Burton ◽  
Michele E. Koehler ◽  
William I. Atlas ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Population Expansion ◽  
Fishing Mortality ◽  
Fish Ladder ◽  
Accessible Habitat ◽  
Over Time

Following construction of a fish ladder at Landsburg Diversion Dam on the Cedar River, Washington, USA, in fall 2003, we used DNA-based parentage to identify second generation Chinook (Oncorhynchus tshawytscha) and coho (Oncorhynchus kisutch) salmon as recruits that were produced above the dam or “strays” dispersing into the new habitat that were produced elsewhere. For both species, strays colonized immediately but decreased as a proportion of the total run over time. Chinook salmon strays were more numerous in years when the species was more abundant below the dam and included a much larger proportion of hatchery origin salmon than did coho salmon. Productivity, calculated as the ratio of female recruits sampled at the dam to female spawners, exceeded replacement in all four coho salmon cohorts but only two of five Chinook salmon cohorts, leading to more rapid population expansion of coho salmon. However, estimates of fishing mortality and recruitment into the Cedar River below the dam substantially increased Chinook salmon productivity estimates. Our results demonstrate that Pacific salmon are capable of rapidly recolonizing habitat made accessible by restoration and emphasize the importance of demographic exchange with preexisting populations during the transition from recolonization to self-sustainability.

Differences in acquired and innate resistance among Pacific salmon (Oncorhynchus spp.) against the haemoflagellate Cryptobia salmositica and numbers delivered by the leech vector Piscicola salmositica

1995 ◽  
Vol 52 (S1) ◽  
pp. 1-6 ◽  
Author(s):  
S.M. Bower
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Elevated Temperatures ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Lytic Activity ◽  
Juvenile Chinook Salmon ◽  
Elevated Water ◽  
Plasma Factors

Susceptible juvenile chinook salmon (Oncorhynchus tshawytscha) were protected from otherwise lethal challenges with the haemoflagellate Cryptobia salmositica by acclimation to an elevated water temperature (20 °C). Following challenge at temperatures advantageous to the haemoflagellate (9–11 °C), surviving fish had plasma with enhanced acquired lytic activity against the parasite. In contrast, most coho salmon (Oncorhynchus kisutch) from a resistant stock survived up to three challenges with C. salmositica, without "immunization" at elevated temperatures. However, they acquired little or no lytic activity against the parasite, which survived in low numbers in some fish. Also, the chinook and coho salmon did not have innate plasma factors that lysed the parasite under in vitro conditions like those demonstrated in other salmonids. Thus, the mechanism(s) that protect the resistant O. kisutch from the pathogenic affects of C. salmositica are different from those identified in other fishes that are resistant to Cryptobia spp. A challenge of 105 flagellates per fish was suggested to be representative of the number of C. salmositica inoculated into a fish by one infected leech vector (Piscicola salmositica).

Review of the Rate of Growth and Mortality of Pacific Salmon in Salt Water, and Noncatch Mortality Caused by Fishing

1976 ◽  
Vol 33 (7) ◽  
pp. 1483-1524 ◽  
Author(s):  
W. E. Ricker
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Pink Salmon ◽  
Total Yield ◽  
Coastal Region ◽  
Natural Mortality ◽  
Time Of Year

Mortality (other than landed catch) caused by pelagic gillnetting is estimated to be equal to the catch, for salmon in their penultimate year of life, and equal to about a quarter of the catch for salmon in their final year of life. Mortality caused by trolling for coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) averages about one fish killed (mostly below legal size) for every two that are boated. The natural mortality rate for sockeye salmon (O. nerka) in their final year of life averages about 0.015 per mo and is somewhat more in earlier years of pelagic life; the greater part of natural mortality after the smolt stage occurs during the downstream migration and early months of "coastal" life. For coho and chinook the best natural mortality estimate for the last year of life is 0.013 per mo, and that for pink (O. gorbuscha) and chum (O. keta) is of the same order. Growth rates during the final growing season vary from 0.26 per mo for pink and coho salmon to 0.06 per mo for chinook in their 5th ocean yr. Gains from ceasing to take immature salmon on the high seas range up to 300% of the catch now being taken in that category, while for fish taken in their final year they range up to about 70%, depending on the time of year at which the fishing is done. Gains from transferring existing pelagic net fisheries to the coastal region would be 76% (North American sockeye) and 86% (Asian sockeye) of the weight of fish now caught pelagically. Gains in total yield of existing salmon fisheries (pelagic and coastal) are estimated as 78% for Asian pink salmon and 72% for Asian sockeye. The increase in weight of the total catch from discontinuing ocean trolling for Columbia River chinook salmon and increasing river fishing correspondingly is estimated tentatively as between 63 and 98%.

Field Testing of Injected Vibrio anguillarum Bacterins in Pen-Reared Pacific Salmon

1976 ◽  
Vol 33 (6) ◽  
pp. 1291-1296 ◽  
Author(s):  
Ross Antipa
Keyword(s):  
Chinook Salmon ◽  
Intraperitoneal Injection ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Serum Antibody ◽  
Vibrio Anguillarum ◽  
Field Testing ◽  
Aeromonas Salmonicida ◽  
Control Group

Intraperitoneal injection of three types of Vibrio anguillarum bacterin (heat-killed, formalin-killed, and a combination of heat and formalin-killed) was tested in Chinook (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) to assess the feasibility of preventing vibriosis by immunization in commercial aquaculture. A single injection of V. anguillarum bacterin gave substantial protection to chinook salmon for 6 mo postinoculation (32% mean mortality in all injected groups) in comparison to the control group (85% mortality). Chinook salmon showed the highest survival when treated with the heat-killed V. anguillarum bacterin. All groups of coho salmon had less than 7.0% mortality, and immunization was not beneficial to survival. Serum antibody titer of V. anguillarum agglutinins was increased by intraperitoneal injection. Vibrio anguillarum was the pathogen most frequently isolated from moribund chinook salmon; Aeromonas salmonicida was the predominant organism isolated from moribund coho salmon.

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