Variation in Length and Body Depth of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta) in Southern British Columbia

1985 ◽  
Vol 42 (2) ◽  
pp. 312-319 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Body Depth ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Gain Access

The magnitude of within-stock variability of postorbital–hypural length and body depth was investigated for spawning pink salmon (Oncorhynchus gorbuscha) and chum salmon (O. keta) stocks. Variability of postorbital–hypural length and body depth of male pink salmon, all maturing at 2 yr of age, was greater than that for male chum salmon, maturing at ages of 3–5 yr. Female pink salmon were less variable for the two characters than all ages of female chum salmon, equally variable when only age 3 or age 4 female chum salmon were considered, and more variable in comparison with age 5 female chum salmon. Males were more variable for each character than females for both species. Small males of both species tend to resemble females when body depths are compared. It is suggested that small males mimic females to reduce aggression from larger males and gain access to spawning females.

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.

scholarly journals Principles Affecting the Size of Pink and Chum Salmon Populations in British Columbia

1953 ◽  
Vol 9a (9) ◽  
pp. 450-491 ◽  
Author(s):  
Ferris Neave
Keyword(s):  
British Columbia ◽  
Egg Production ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Fish Populations ◽  
Oncorhynchus Gorbuscha ◽  
Combined Effects ◽  
Adult Fish ◽  
Free Swimming ◽  
Pink Salmon Oncorhynchus Gorbuscha

In pink salmon (Oncorhynchus gorbuscha) the survival during the freshwater phases of the life-cycle has been found to vary from about 1 to 24 per cent of available eggs. Natural survival during marine existence is considered to average about 5 per cent. In the central region of the British Columbia coast the annual catch averages about 60 per cent of the adult fish. Populations maturing in "even" and "odd" years vary in size independently. Fluctuations in level of stock originate mainly in fresh water.Population levels and changes are determined by the combined effects of three types of mortality: (a) mortality which becomes relatively heavier as populations increase in density (compensatory); (b) mortality which becomes relatively heavier as populations decrease in density (depensatory); (c) mortality which is independent of density (extrapensatory). Compensatory mortality is especially identified with the, period of spawning and incubation. Depensatory mortality is considered to occur mainly during the period of fry migration and to be due to predation. Extrapensatory mortality may occur at any stage; it is most variable during the period between entrance of the adults into fresh water and emergence of the free-swimming fry.Populations of chum salmon (O. keta) are controlled by similar influences. Effects are modified by higher egg-production and a less rigid life-span than in the pink salmon.

Orientation of Pink Salmon (Oncorhynchus gorbuscha) During Early Marine Migration from Bella Coola River System

1967 ◽  
Vol 24 (11) ◽  
pp. 2321-2338 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
River System ◽  
Early Morning ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Marine Migration ◽  
Bella Coola

During May and June 1966, the migration of pink salmon fry from the Bella Coola River was studied in Burke Channel, British Columbia. The movement of pink fry down Burke Channel was saltatory. Short periods of active migration were interspersed with longer periods when the fry did not migrate and accumulated in bays. Fry were sampled from these accumulations and their ability to orient using celestial cues was examined. During the early morning, fry tended to prefer directions at right angles to their direction of migration, but at other times of the day preferred the direction of migration. The preference for the direction of migration was strongest at midday. Fry were better oriented on clear days than on cloudy days. These data indicate that fry may use celestial cues to find directions during their oceanic migrations.

Statistical Evaluation of a Large-Scale Fishing Experiment Designed to Test for a Genetic Effect of Size-Selective Fishing on British Columbia Pink Salmon (Oncorhynchus gorbuscha)

1992 ◽  
Vol 49 (7) ◽  
pp. 1294-1304 ◽  
Author(s):  
Murdoch K. McAllister ◽  
Randall M. Peterman ◽  
Darren M. Gillis
Keyword(s):  
British Columbia ◽  
Statistical Power ◽  
Large Scale ◽  
Pink Salmon ◽  
Genetic Effect ◽  
Oncorhynchus Gorbuscha ◽  
Causal Mechanism ◽  
Block Designs ◽  
Adult Size ◽  
Pink Salmon Oncorhynchus Gorbuscha

Since 1950, stocks of British Columbia pink salmon (Oncorhynchus gorbuscha) have shown up to a 34% decrease in mean adult body weight, causing significant reduction in economic value of commercial harvests. Previous research suggests that this trend is due to size-selective harvesting of large fish, but changes in oceanographic conditions are a plausible alternative. Corrective action by management agencies requires that the true causal mechanism be identified. We therefore examined several possible designs for a large-scale fishing experiment devised to test the size-selective fishing hypothesis. These designs would generate accurate and precise field estimates of the heritability (h2) of growth rate, which is important because it, in combination with the selection differential (D) caused by fishing, determines how rapidly body size changes. Monte Carlo simulations showed that block designs with three to six spatial replicates and relatively short durations generated high statistical power. For example, for h2 = 0.22, D = 0.25 kg, and four spatial replicates, an 8-yr experiment resulted in power = 0.87, which gave a SE < 0.10 for h2 = 0.22. We conclude that some experimental designs have good potential to test the possible effects of size-selective fishing on mean adult size of British Columbia 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

The metacercaria of Galactosomum phalacrocoracis (Trematoda: Heterophyidae) from pink salmon, Oncorhynchus gorbuscha, from British Columbia waters

1978 ◽  
Vol 56 (10) ◽  
pp. 2235-2238 ◽  
Author(s):  
J. C. Pearson ◽  
L. Margolis ◽  
N. P. Boyce
Keyword(s):  
British Columbia ◽  
Coastal Waters ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

The metacercaria of Galactosomum phalacrocoracis (Trematoda: Heterophyidae), collected from Oncorhynchus gorbuscha (Walbaum) from coastal waters of British Columbia, is described.

Evaluation of the Transplant of Pacific Pink Salmon (Oncorhynchus gorbuscha) from British Columbia to Newfoundland

1975 ◽  
Vol 32 (12) ◽  
pp. 2343-2356 ◽  
Author(s):  
W. H. Lear
Keyword(s):  
British Columbia ◽  
Environmental Conditions ◽  
Brook Trout ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Homing Behavior ◽  
Migration Patterns ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Surface Temperatures

Five transplants of eyed eggs of Pacific pink salmon (Oncorhynchus gorbuscha) were made between streams in southern British Columbia and North Harbour River, Newfoundland. Quantities transplanted were 0.25 million in 1959, 2.5 million in 1962, 3.4 million in 1964, 3.3 million in 1965, and 5.9 million in 1966. Adult returns from these transplants were 1, 49, 638, 8500, and 2426 during 1961, 1964, 1966, 1967, and 1968, respectively. Since 1969, returns have been the progeny of naturally spawning fish and have steadily declined in numbers. The reasons for failure of the transplant are not certain, but possibilities include the following: predation on the fry by brook trout and possibly eels in North Harbour Pond and estuary; unfavorable surface temperatures in the river during the fry run; predation by herring on fry in St. Mary’s Bay; year-class failure of the even-year stocks that were introduced; unsuitability of the donor stocks with respect to migration patterns and homing behavior; inadequate numbers of eggs were transplanted to produce populations required to maintain runs in anything below optimum environmental conditions.

Transplantation of Pink Salmon (Oncorhynchus gorbuscha) into Masset inlet, British Columbia, in the Barren Years

1938 ◽  
Vol 4a (2) ◽  
pp. 141-150 ◽  
Author(s):  
A. L. Pritchard
Keyword(s):  
British Columbia ◽  
East Coast ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Fraser River ◽  
Free Swimming ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
The Absolute ◽  
River Fishery

In 1931, 1933, 1935, odd-numbered years, when no natural runs of pink salmon (Oncorhynchus gorbuscha) occur in the Masset area, British Columbia, transfers of eggs were made from the Tlell river on the east coast of Graham island to McClinton creek, a tributary of Masset inlet. The following free-swimming fry were released: from the 1931 experiment—753,646 normal and 124,002 "marked" by the removal of the adipose and left ventral fins, and from that of 1935—397,657 normal and 108,200 "marked" by the removal of the adipose and right ventral fins. From the former, 40 "marked" adults were recovered in the Fraser river fishery in 1933, and from the latter four "marked" adults at McClinton creek in 1937. In the 1933 experiment 540,294 eyed eggs were planted but these were destroyed by freshets the following winter. Possible reasons for the failure of these experiments and the absolute blank in the "off" years are suggested.

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