Growth Rate of Central British Columbia Pink Salmon (Oncorhynchus gorbuscha)

1964 ◽  
Vol 21 (5) ◽  
pp. 1101-1128 ◽  
Author(s):  
R. J. LeBrasseur ◽  
R. R. Parker
Keyword(s):  
Growth Rate ◽  
British Columbia ◽  
Pink Salmon ◽  
Growth Period ◽  
Oncorhynchus Gorbuscha ◽  
Instantaneous Growth Rate ◽  
Commercial Fishery ◽  
Instantaneous Rate ◽  
Instantaneous Growth ◽  
Rate Of Increase

Pink salmon were sampled at various stages, as fry and fingerling in enclosed waters, as juveniles and subadults in the ocean and as maturing salmon in the commercial fishery. On the basis of length frequency data and from recapture measurements of marked and tagged individuals the instantaneous growth rate in length (gl) for successive 30-day periods was computed. As a result three major growth stanzas were recognized. Following the entrance of fry into the estuary, growth was approximately exponential (gl = 0.559) during an initial 40-day period. Fish increased in length from 3.5 to 8.4 cm. Thereafter, the instantaneous rate of growth gradually declined to a minimum in March (gl = 0.076). During this time the length increased from 8.4 to 32.5 cm. The final growth period was marked by a rapid rate of increase in length in late April and early May (gl = 0.171), followed by a declining rate of increase in length which was finally terminated after the fish had re-entered the coastal waters and the commercial fishery (gl = 0.041). The length data were transformed to weight data from a generalized length–weight regression. During the initial 30-day period the instantaneous growth rate in weight, gw = 6.53. From a value of gw = 2.87 for late May and early June the instantaneous growth rate progressively fell to a low of gw = 1.28 for late March to early April. During late April to early May of the ultimate year, gw = 1.74. The instantaneous growth rate then fell to gw = 1.14 during mid July to early August. It was concluded that growth, in length and weight, of central British Columbia pink salmon is a continuing process with no period of complete cessation from the time the fry enter the sea until the time they re-enter the estuary as adults.

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.

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

Energy Dynamics of the Eutrophic Chironomid Chironomus plumosus f. semireductus from the Bay of Quinte, Lake Ontario

1980 ◽  
Vol 37 (8) ◽  
pp. 1254-1265 ◽  
Author(s):  
Ora E. Johannsson
Keyword(s):  
Growth Rate ◽  
Feeding Rate ◽  
Assimilation Efficiency ◽  
Growth Efficiency ◽  
Time Of Day ◽  
Organic Content ◽  
Algal Community ◽  
Instantaneous Growth Rate ◽  
Larval Size ◽  
Instantaneous Growth

Relationships between feeding rate, temperature, body size, and time of day were investigated and collated with seasonal assimilation efficiencies of in situ chironomids to construct a picture of chironomid energetics over the year. Temperature controlled feeding rate, and larval size and time of day exerted no effect. The temperature optimum plateaued between 22.0 and 24.5 °C, decreasing logarithmically outside this range. Both assimilation efficiency (AE) and organic content of the food varied seasonally, but were not correlated. Periods of high AE corresponded with the latter part of Melosira or Melosira–Stephanodiscus blooms, while periods of low AE occurred between diatom blooms and during the late summer blue-green bloom. Consequently, growth fluctuated throughout the year, being a result of the interaction of temperature and AE. Anabolic processes dominated at AE greater than 3.5%. Maximum net growth efficiency (NGE) was attained when AE ≥ 6% and temperature ≥ 15 °C. NGE was more sensitive to changes in AE than temperature. Instantaneous growth rate, however, was more sensitive to changes in temperature. Daily ingestion (mg) exceeded body weight by as much as 460–480%, which equals the sediment-processing capacity of freshwater detritivores.Key words: chironomid, feeding rate, assimilation efficiency, instantaneous growth rate, net growth efficiency, algal community, Bay of Quinte

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.

Size Selective Predation Among Juvenile Salmonid Fishes in a British Columbia Inlet

1971 ◽  
Vol 28 (10) ◽  
pp. 1503-1510 ◽  
Author(s):  
Robert R. Parker
Keyword(s):  
Growth Rate ◽  
British Columbia ◽  
Prey Population ◽  
Oncorhynchus Gorbuscha ◽  
Field Observations ◽  
Salmonid Fishes ◽  
Selective Predation ◽  
Initial Size ◽  
Salmon Fry ◽  
Series Of Experiments

Field observations suggest early sea mortality of pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon fry is largely due to predation by juvenile coho (O. kisutch) salmon. A series of experiments demonstrates a strong bias toward the smaller individuals of the prey population. This results in an apparent growth rate 0.3–0.5% per day due to the biased mortality alone. With a high innate growth rate [Formula: see text], the prey are shown to "outgrow" the predator [Formula: see text], and hence become unavailable. Chums are shown to have an advantage over pinks through slightly earlier entry into the estuary and a larger initial size. The mechanism of selection used by the predator is not known from this study.

The influence of population dynamics and environmental conditions on pink salmon (Oncorhynchus gorbuscha) recolonization after barrier removal in the Fraser River, British Columbia, Canada

2012 ◽  
Vol 69 (5) ◽  
pp. 970-982 ◽  
Author(s):  
G.R. Pess ◽  
R. Hilborn ◽  
K. Kloehn ◽  
T.P. Quinn
Keyword(s):  
British Columbia ◽  
Abiotic Factors ◽  
Pink Salmon ◽  
River System ◽  
Oncorhynchus Gorbuscha ◽  
Source Population ◽  
Fraser River ◽  
Extrinsic Factors ◽  
Barrier Removal

When barriers are removed, what biotic and abiotic factors determine how fish populations will colonize newly available habitats? We used counts of adult pink salmon ( Oncorhywnchus gorbuscha ) from 1947 to 1987 in 66 streams of the Fraser River system, British Columbia, Canada, to determine when colonizing pink salmon populations became self-sustaining after a long-term migration blockage at Hell’s Gate (river kilometre 209) was reduced. The abundance of salmon in available habitats were largely controlled by extrinsic factors such as an initially large source population, high intrinsic growth rates linked to favorable climate-driven conditions, a constant supply of dispersers, and large amounts of newly available habitat. Temporal variation in flows at Hell’s Gate also affected recolonization success. Self-sustaining populations were developed within years of barrier removal and have continued to help expand the overall population of Fraser River pink salmon. However, pink salmon were considerably more abundant in the early 1900s than in the 1980s (∼48 million vs. ∼2.7 million), and the majority of spawning shifted from the historic areas above Hell’s Gate prior to the rockslide to below Hell’s Gate in the lower Fraser River after the long-term blockage was reduced, so the system has not returned to the former abundance and distribution patterns.

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