Competition between juvenile pink (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) and its effect on growth and survival

1993 ◽  
Vol 71 (6) ◽  
pp. 1270-1274 ◽  
Author(s):  
Terry D. Beacham
Keyword(s):  
Relative Abundance ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Fraser River ◽  
Growth And Survival ◽  
Competitive Effects ◽  
Chum Salmon Oncorhynchus Keta ◽  
The Mean

Pink (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) fry have the potential for significant interactions in estuarine and nearshore waters of the Fraser River. Potential competitive effects were investigated by rearing both species for 60 d from fry emergence in monoculture and five duoculture environments (0, 10, 25, 50, 75, 90, and 100% pink salmon, and 100, 90, 75, 50, 25, 10, and 0% chum salmon, respectively), with the total number of fish in each environment constant. As the relative abundance of chum salmon increased, the mean weight of both pink and chum salmon declined, and reduced phenotypic variation in weight was observed. No marked trends in survival were observed in either species, but there was some indication that pink salmon survival was higher at intermediate relative densities of pink and chum salmon. Pink salmon biomass increased from 0.8 to 1.8%/d depending on the environment, and chum salmon biomass increased from 3.2 to 3.8%/d.

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.

Intra- and inter-specific competition and the reproductive success of sympatric Pacific salmon

2000 ◽  
Vol 57 (1) ◽  
pp. 205-213 ◽  
Author(s):  
Timothy E Essington ◽  
Thomas P Quinn ◽  
Victor E Ewert
Keyword(s):  
Reproductive Success ◽  
Relative Abundance ◽  
Pacific Salmon ◽  
Interspecific Interactions ◽  
Pink Salmon ◽  
Abundant Species ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Competitive Effects ◽  
Microhabitat Preferences

Individual female Pacific salmon fight for breeding space with conspecific and heterospecific females. We evaluated the consequences of this competition on the reproductive success of sockeye (Oncorhynchus nerka), chum (Oncorhynchus keta), and pink salmon (Oncorhynchus gorbuscha) in the Weaver Creek spawning channel, British Columbia. We hypothesized that differences in body size, relative abundance, and spawning date would influence the magnitude of interspecific interactions. Reproductive success (survival rate of eggs to emigrating fry) of the most abundant species, sockeye, was strongly and inversely correlated with conspecific abundance but not with the abundance of the other, less abundant species. Chum reproductive success was inversely correlated with sockeye abundance but not with the abundance of the scarce and smaller pink. Surprisingly, pink reproductive success was not correlated with sockeye abundance and only marginally correlated with chum abundance despite the fact that pink are smaller and spawn earlier than sockeye. Thus, intra- and inter-specific competition can substantially affect salmon reproductive success, but the magnitude of the competitive effects may depend on relative abundance, size, spawning date, and microhabitat preferences.

Biochemical Genetic Survey and Stock Identification of Chum Salmon (Oncorhynchus keta) in British Columbia

1987 ◽  
Vol 44 (10) ◽  
pp. 1702-1713 ◽  
Author(s):  
T. D. Beacham ◽  
A. P. Gould ◽  
R. E. Withler ◽  
C. B. Murray ◽  
L. W. Barner
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Electrophoretic Analysis ◽  
South Coast ◽  
Oncorhynchus Keta ◽  
Stock Identification ◽  
Fraser River ◽  
Genetic Method ◽  
Chum Salmon Oncorhynchus Keta ◽  
Queen Charlotte Islands

We examined genetic variability using electrophoretic analysis of 83 chum salmon (Oncorhynchus keta) stocks in British Columbia and used regional differences in genotypic frequencies of seven polymorphic loci to estimate stock compositions in a number of commercial and experimental test fisheries. Chum salmon from five regions could be discriminated: Queen Charlotte islands, north and central coast, west coast of Vancouver Island, the Fraser River and its tributaries, and the south coast (rivers draining into Johnstone Strait and the Strait of Georgia). Allelic frequencies from 33 stocks were generally stable over a period of 2 yr or more. South coast chum salmon was the dominant run migrating through upper Johnstone Strait in October 1982–85. The genetic method of stock identification provided managers with the relative proportions of Fraser River and other groups of chum salmon in a number of fisheries and allowed managers to regulate more effectively the exploitation rate of Fraser River chum salmon.

Comparative Developmental Biology of Chum Salmon (Oncorhynchus keta) from the Fraser River, British Columbia

1986 ◽  
Vol 43 (2) ◽  
pp. 252-262 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
Developmental Biology ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Fraser River ◽  
Egg Survival ◽  
Tissue Weight ◽  
Chum Salmon Oncorhynchus Keta ◽  
Hatching Time ◽  
Spawning Time ◽  
Incubation Temperatures

Eggs and alevins from 32 families of chum salmon (Oncorhynchus keta) from seven Fraser River stocks spawning at different times or in different tributaries were incubated in controlled water temperatures of 4, 8, and 12 °C. There were significant differences in egg and alevin survival among stocks and among families within stocks in the different incubation temperatures. Highest egg survival for a late-spawning Vedder River stock occurred at 4 °C, while egg survival from other stocks was highest at 8 °C. Late-spawning stocks had smaller eggs and earlier times of fry emergence than did early-spawning ones. There was no effect of spawning time on alevin hatching time. Alevins hatching at 8 °C were larger than those hatching at 4 or 12 °C, but there were no stock differences in alevin length or tissue weight. Stocks with greater egg sizes produced alevins of greater total weight. Fry emerging at 8 °C were larger than those emerging at 4 or 12 °C, and fry from early-spawning stocks were longer and had greater tissue weight than those from late-spawning ones. There were significant differences among families within stocks in size of alevins and fry, and family differences should be accounted for in studies of salmonid developmental biology.

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.

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

Growth of Juvenile Chum Salmon (Oncorhynchus keta) Under Different Feeding Regimes

1969 ◽  
Vol 26 (6) ◽  
pp. 1631-1645 ◽  
Author(s):  
R. J. LeBrasseur
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Rate Of Growth ◽  
Total Length ◽  
Chum Salmon Oncorhynchus Keta ◽  
Feeding Regimes ◽  
Size Groups ◽  
Juvenile Chum Salmon ◽  
The Mean

Juvenile chum salmon were fed on six different concentrations of size-selected zooplankton for 8 weeks. Zooplankton were caught daily and sorted through sieves into size-groups roughly as follows: 6–20 mm total length, mainly euphausiids; 2.5–4.5 mm, mainly copepods; and ≤ 1.5 mm, mainly small copepods. The rate of growth in weight of the fish was found to be dependent upon the concentration of the ration. Fish which were offered no food lost weight, and fish which were offered excess food increased in weight by 5.4% per day. The mean growth rate of the fish held on fixed rations ranged from 2.2 to 5.7% per day and was found to be independent of the type of prey. Electivity experiments showed that all the fish selected copepods 1.6–4.5 mm long in proportion to their abundance and rejected copepods ≤ 1.5 mm. The euphausiids were selected only by fish which had previously fed on euphausiids. The effect of variations in the availability of prey is discussed.

Biochemical Genetic Stock Identification of Chum Salmon (Oncorhynchus keta) in Southern British Columbia

1985 ◽  
Vol 42 (3) ◽  
pp. 437-448 ◽  
Author(s):  
Terry D. Beacham ◽  
Ruth E. Withler ◽  
Allan P. Gould
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Vancouver Island ◽  
Oncorhynchus Keta ◽  
Significant Heterogeneity ◽  
Stock Identification ◽  
Fraser River ◽  
Genetic Stock ◽  
Allelic Frequencies ◽  
Chum Salmon Oncorhynchus Keta

We used electrophoresis to examine genetic variability of 33 chum salmon (Oncorhynchus keta) stocks in southern British Columbia and used differences in genotypic frequencies among these stocks for estimating stock compositions in a weekly fishery in upper Johnstone Strait. Seven polymorphic loci were used for stock identification. Chum salmon from the Fraser River, Bute and Toba inlets, Vancouver Island, and the southern Mainland had significantly different allelic frequencies, but there was also significant heterogeneity in allelic frequencies at some loci within each region. Allelic frequencies were generally stable over a 2-yr period in nine stocks for which consecutive annual sampling was conducted. There was no significant two-locus linkage disequilibrium for the chum salmon stocks surveyed. Cluster analysis indicated that Fraser River and Bute and Toba Inlet stocks were distinctive, but Vancouver Island and Mainland stocks were not. The timing and relative abundance of Fraser River chum salmon in upper Johnstone Strait as estimated by electrophoretic analysis was confirmed by an in-river test fishery in the Fraser River.

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