Trophic Analysis of Juvenile Pink and Chum Salmon (Oncorhynchus gorbuscha and O. keta) in Puget Sound

1973 ◽  
Vol 30 (7) ◽  
pp. 1003-1008 ◽  
Author(s):  
V. W. Kaczynski ◽  
R. J. Feller ◽  
J. Clayton ◽  
R. J. Gerke
Keyword(s):  
Chum Salmon ◽  
Pink Salmon ◽  
Puget Sound ◽  
Stomach Contents ◽  
Life Cycles ◽  
Oncorhynchus Gorbuscha ◽  
Stage Of Development ◽  
Harpacticoid Copepods ◽  
Trophic Analysis

Pink and chum salmon (Oncorhynchus gorbuscha and O. keta) fry and Clarke–Bumpus plankton tows were collected from three beach areas in Puget Sound in spring 1970. Chum fry and benthic pump samples were taken in 1971. The diets of the young of the two species were similar. Epibenthic harpacticoid copepods were the chief prey of the chum and pink salmon (57 and 36%, respectively, in 1970). Distinct differences were apparent, the more notable being the preference for invertebrate eggs exhibited by the pinks and the higher preferences for small gammarid amphipods and harpacticoids exhibited by the chums. The stomach contents showed no resemblance to the plankton hauls taken in the same area. The onshore stage of development appears to be a distinct ecological stage in the life cycles of these species.

Supplementary Checks on the Scales of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta)

1965 ◽  
Vol 22 (6) ◽  
pp. 1477-1489 ◽  
Author(s):  
H. T. Bilton ◽  
W. E. Ricker
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Commercial Fisheries ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Clear Cut ◽  
Second Year Of Life ◽  
Second Year ◽  
Similar Incidence

Among 159 central British Columbia pink salmon that had been marked by removal of two fins as fry and had been recovered in commercial fisheries after one winter in the sea, the scales of about one-third showed a supplementary or "false" check near the centre of the scale, in addition to the single clear-cut annulus. This evidence from fish of known age confirms the prevailing opinion that such extra checks do not represent annuli, hence that the fish bearing them are in their second year of life rather than their third. Unmarked pink salmon from the same area, and some from southern British Columbia, had a generally similar incidence of supplementary checks. In both marked and unmarked fish the supplementary checks varied in distinctness from faint to quite clear. In a sample of scales of 14 double-fin marked chum salmon which were known to be in their 4th year, all fish had the expected 3 annuli, and 12 fish had a supplementary check inside the first annulus.

Migratory dynamics and characteristics of breeding pink salmon (Oncorhynchus gorbuscha) from the Carp River, eastern Lake Superior

1990 ◽  
Vol 68 (4) ◽  
pp. 684-693 ◽  
Author(s):  
Douglas B. Noltie
Keyword(s):  
Lake Superior ◽  
Pink Salmon ◽  
Life Cycles ◽  
Oncorhynchus Gorbuscha ◽  
Gonad Maturation ◽  
Breeding Ecology ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Light Levels ◽  
Breeding Migration ◽  
Fish Remains

The pink salmon (Oncorhynchus gorbuscha) inhabiting the Great Lakes are unique to their species, the completion of their life cycles occurring entirely in fresh water. This report describes the breeding migration and characteristics of spawners from the Carp River, an eastern Lake Superior tributary 70 km north of Sault Ste. Marie, Ontario. Movement into the stream began at dusk each evening in 1983, seemingly in response to decreasing light levels. Nightly catch numbers varied through the 1983, 1984, and 1985 runs with date, river discharge, wind-generated turbulence, and water temperatures, although the influence of these factors differed with sex and season. Spawners varied in size through the runs each year but not in the same fashion. Spawner size and condition varied yearly in apparent response to prey abundance. Gonad maturation was complete on stream entry more often in males than in females, though this difference was less pronounced further upstream or after time spent in the river. Degree of secondary sexual character development, complete on stream entry in both sexes, differed in even- and odd-year spawners in relation to condition. The recovery rates of spawned-out males and females did not differ. Tagged fish wandered from the Carp River at a rate of at least 7%, many to spawn in adjacent streams. Despite between-year differences in some parameters, much of the breeding ecology of these fish remains comparable to that of anadromous pink salmon.

Daily Patterns of Feeding Behavior, Daily Rations, and Diets of Juvenile Pink Salmon (Oncorhynchus gorbuscha) in Two Marine Bays of British Columbia

1981 ◽  
Vol 38 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Jean-Guy J. Godin
Keyword(s):  
British Columbia ◽  
Feeding Behavior ◽  
Littoral Zone ◽  
Pink Salmon ◽  
Early Period ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Harpacticoid Copepods ◽  
Additional Support

Stomach analyses showed that pink salmon fry fed mainly during daylight hours in the littoral zone of Departure Bay and Hammond Bay, British Columbia, in May. Although the diurnal feeding patterns of the fish differed slightly between the two bays, maximum mean prey biomass in the fishes' stomachs occurred near or at dusk in both bays. Daily rations consumed by Departure Bay and Hammond Bay fish were estimated to be 13.1 and 6.6% of their dry body weight, respectively. The fry consumed similar prey items in both bays, but in differing proportions. Harpacticoid copepods, copepod nauplii, and barnacle larvae comprised numerically 93.1 and 86.2% of the diets of Departure Bay and Hammond Bay fish, respectively. About 38% of the diet of Departure Bay fish and 51% of the diet of Hammond Bay fish comprised epibenthic prey, mainly harpacticoid copepods. The data provide additional support for the importance of the detritus-microbe-consumer type food chain supporting the production of pink salmon during their early period of marine residency.Key words: pink salmon, feeding behavior, daily rhythm, diet, ration, British Columbia

Genetic Effect on the Dynamics of a Model of Pink (Oncorhynchus gorbuscha) and Chum (O. keta) Salmon

1984 ◽  
Vol 41 (10) ◽  
pp. 1446-1453 ◽  
Author(s):  
William W. Smoker
Keyword(s):  
Chum Salmon ◽  
Pink Salmon ◽  
Genetic Effect ◽  
Genetic Mechanism ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
High Heritability ◽  
Maturation Age

Different stock dynamics result from genetic and nongenetic mechanisms of determination of maturation age of chum salmon (Oncorhynchus keta) in a model of interacting pink (O. gorbuscha) and chum salmon stocks. When the model is disturbed from equilibrium by low survival in one pink salmon line, the genetic mechanism (high heritability of maturation age) leads to biennial cycles of numbers of even-aged chums and of numbers of pinks, similar to observed cycles. The nongenetic mechanism (zero heritability of maturation age) results in a new equlibrium at which neither stock cycles. When one pink salmon line is completely removed the genetic mechanism leads to biennial cycles of abundance of even-aged chums; the nongenetic mechanism does not lead to such cycles. These effects persist at intermediate values of heritability of maturation age and in spite of stochastic variability. The model is an adaptation of the Ricker curve to two interacting stocks, the recruitment for each depending on the density of both.

Stomach Contents of Salmon and Steelhead Trout in the Northeastern Pacific Ocean

1966 ◽  
Vol 23 (1) ◽  
pp. 85-100 ◽  
Author(s):  
R. J. LeBrasseur
Keyword(s):  
Pacific Ocean ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Pink Salmon ◽  
Stomach Contents ◽  
Northwestern Pacific ◽  
Steelhead Trout ◽  
Fish Size ◽  
Northeastern Pacific

Stomachs of pink, chum, sockeye, and coho salmon and steelhead trout caught during the summer of 1958 in gillnets fished overnight in the northeastern Pacific Ocean contained mainly zooplankton (Limacina, amphipods, copepods, and euphausiids), squid, and fish. Except for sockeye, there were no differences in contents related to fish size or state of maturity. Differences were found between species in the kinds of stomach contents present. The predominant organisms were amphipods and fish in pink salmon, crustaceans in immature sockeye, euphausiids and squid in maturing sockeye, euphausiids, fish, and squid in coho, and fish and squid in steelhead stomachs. The stomach contents of chum salmon were notable in that most of their contents were too well digested to identify. Comparison with the findings of workers in the northwestern Pacific showed no significant differences in the kinds of stomach contents, however, a greater amount of material was present in the stomachs they examined. The contents of stomachs from fish taken in various ocean domains were compared. Greater differences were noted in the stomach contents of fish from different domains than from different species. It is suggested that feeding is associated more with availability rather than with preferences for specific organisms.

scholarly journals Response of the Sea Louse Lepeophtheirus salmonis Infestation Levels on Juvenile Wild Pink, Oncorhynchus gorbuscha, and Chum, O. keta, Salmon to Arrival of Parasitized Wild Adult Pink Salmon

2006 ◽  
Vol 120 (2) ◽  
pp. 199
Author(s):  
Alexandra Morton ◽  
Rob Williams
Keyword(s):  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Primary Source ◽  
Sea Lice ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Lepeophtheirus Salmonis ◽  
Louse Infestation ◽  
Age Cohorts

Recent recurring infestations of Sea Lice, Lepeophtheirus salmonis, on juvenile Pacific salmon (Oncorhynchus spp.) and subsequent annual declines of these stocks have made it imperative to identify the source of Sea Lice. While several studies now identify farm salmon populations as sources of Sea Louse larvae, it is unclear to what extent wild salmonid hosts also contribute Sea Lice. We measured Sea Louse numbers on adult Pink Salmon (Oncorhynchus gorbuscha) migrating inshore. We also measured Sea Louse numbers on wild juvenile Pink and Chum salmon (Oncorhynchus keta) migrating to sea before the adults returned, and as the two age cohorts mingled. Adult Pink Salmon carried an average of 9.89 (SE 0.90) gravid lice per fish, and thus were capable of infecting the adjacent juveniles. Salinity and temperature remained favourable to Sea Louse reproduction throughout the study. However, all accepted measures of Sea Louse infestation failed to show significant increase on the juvenile salmon, either in overall abundance of Sea Lice or of the initial infective-stage juvenile lice, while the adult wild salmon were present in the study area. This study suggests that even during periods of peak interaction, wild adult salmon are not the primary source of the recent and unprecedented infestations of Sea Lice on juvenile Pacific Pink and Chum salmon in the inshore waters of British Columbia.

Times of Annulus Formation on Scales of Sockeye, Pink, and Chum Salmon in the Gulf of Alaska

1966 ◽  
Vol 23 (9) ◽  
pp. 1403-1410 ◽  
Author(s):  
H. T. Bilton ◽  
S. A. M. Ludwig
Keyword(s):  
Chum Salmon ◽  
Annual Ring ◽  
Pink Salmon ◽  
Gulf Of Alaska ◽  
Oncorhynchus Gorbuscha ◽  
Annulus Formation ◽  
Canadian Research

On scales of pink (Oncorhynchus gorbuscha), chum (O. keta), and possibly sockeye (O. nerka) salmon caught by Canadian research vessels throughout the Gulf of Alaska at various times of the year, the annual ring began to form sometime between early November and January. Many of the sockeye and pink salmon had completed the annulus sometime in December or January, whereas the chum salmon completed their's later, in February or March. For both sockeye and chum salmon, scales of younger fish tended to commence new growth at an earlier date than did those of older fish.

Identification of the sex chromosome pair in chum salmon (Oncorhynchus keta) and pink salmon (Oncorhynchus gorbuscha)

2007 ◽  
Vol 116 (4) ◽  
pp. 298-304 ◽  
Author(s):  
R.B. Phillips ◽  
J. DeKoning ◽  
M.R. Morasch ◽  
L.K. Park ◽  
R.H. Devlin
Keyword(s):  
Chromosome Pair ◽  
Chum Salmon ◽  
Sex Chromosome ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta

Meristic and morphometric variation in pink salmon (Oncorhynchus gorbuscha) in southern British Columbia and Puget Sound

1985 ◽  
Vol 63 (2) ◽  
pp. 366-372 ◽  
Author(s):  
Terry D. Beacham
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
Puget Sound ◽  
Genetic Differences ◽  
Oncorhynchus Gorbuscha ◽  
Morphometric Variation ◽  
Morphometric Characters ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Local Water ◽  
Gill Raker

Variation in the number of gill rakers and four morphometric characters was examined for 4 stocks from the even-year brood line and 20 stocks from the odd-year brood line of pink salmon (Oncorhynchus gorbuscha) in southern British Columbia and Puget Sound. Significant differences in gill-raker frequencies were observed among stocks within each brood line, but differences were greater between the brood lines than within each brood line. Sizes of the morphometric characters standardized to a body length of 419 mm were also variable among stocks within a brood line, but stocks spawning in rivers in the same region in alternate years were more similar morphometrically than to those spawning in different regions. It is suggested that patterns of meristic and morphometric variability are reflective of genetic differences, with meristic variability illustrating the genetic differences between the brood lines, and morphometric variability reflecting adaptation to local water velocity conditions in the streams the stocks return to during spawning.

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