Effects of Forest Harvesting on Spawning Gravel and Incubation Survival of Chum (Oncorhynchus keta) and Coho Salmon (O. kisutch) in Carnation Creek, British Columbia

1989 ◽  
Vol 46 (4) ◽  
pp. 681-696 ◽  
Author(s):  
J. C. Scrivener ◽  
M. J. Brownlee

Following logging, pea gravel and sand (i.e. fines) in the stream bed of Carnation Creek, British Columbia increased 4.6 and 5.7%, respectively. The quantity of fines was greater in the bottom layer, while the frequency and magnitude of changes in composition were greater in the top layer of streambed cores. Changes in streambed fines depended on the timing and type of streamside logging and on the timing of large freshets. Accumulating fines appeared to originate from erosion of streambanks or from upstream storage areas and they were transported as bedload. Suspended sediment (11.4–44.5 t∙km−2∙yr−1) did not increase after road construction or logging. Deposition and scour rates of pea gravel and sand in the streambed were inversely related to particle size, and to their depth in the bed. Following logging, survival to emergence declined from 29.1 to 16.4% for coho salmon (Oncorhynchus kisutch) and from 22.2 to 11.5% for chum salmon (O. keta). Annual mean survival to emergence and size of fry of both species were positively related to two indices of substrate composition. Annual changes in substrate composition and peak flows explained 60 and 73% of the variability in survival to emergence for chum and coho salmon, respectively.


1975 ◽  
Vol 32 (9) ◽  
pp. 1640-1643 ◽  
Author(s):  
L. Margolis ◽  
T. P. T. Evelyn

Infections with the myxosporidan Ceratomyxa shasta Noble, 1950 were confirmed in four juvenile chum salmon (Oncorhynchus keta) caught at sea near Nanaimo in 1965 and 1968. These cases represent a new host record for C. shasta and a northward extension of the parasite’s known natural range. Ceratomyxosis was also presumptively diagnosed in a coho salmon (Oncorhynchus kisutch) in British Columbia.



1989 ◽  
Vol 46 (8) ◽  
pp. 1396-1405 ◽  
Author(s):  
L. Blair Holtby ◽  
Thomas E. McMahon ◽  
J. Charles Scrivener

Variability in average stream temperatures between peak spawning and fry emergence accounted for 82 and 77% of the variance in the median emigration date of fry of chum (Oncorhynchus keta) and coho salmon (O. kisutch) respectively over a 9 to 10-yr period. The modeled relationships were indistinguishable from laboratory models that predicted time to maximum alevin wet weight. Variability in stream temperatures during the spring accounted for 60% of the variability in the median date of coho smolt emigration. As stream temperatures increased, the predicted thermal summations required for emigration were nearly constant for coho salmon fry, increased moderately for chum salmon fry and increased strongly for coho salmon smolts The duration of the emigration period also differed between the groups: 50% of the chum salmon fry emigrated over a 1-wk period compared with a 2- to 3-wk period for coho salmon fry and smolts. We speculate that the emigration timing —temperature relationships and timing of adult spawning represent adaptations for synchronizing emigration with "windows of opportunity" in the ocean or stream. The windows are of different widths and levels of predictability for coho and chum salmon fry and coho salmon smolts.



1987 ◽  
Vol 44 (10) ◽  
pp. 1702-1713 ◽  
Author(s):  
T. D. Beacham ◽  
A. P. Gould ◽  
R. E. Withler ◽  
C. B. Murray ◽  
L. W. Barner

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.



2008 ◽  
Vol 86 (9) ◽  
pp. 1002-1014 ◽  
Author(s):  
Terry D. Beacham ◽  
Brian Spilsted ◽  
Khai D. Le ◽  
Michael Wetklo

Variation at 14 microsatellite loci was surveyed in 205 populations of chum salmon ( Oncorhynchus keta (Walbaum in Artedi, 1792)) from British Columbia to determine population structure and the possible application of microsatellites to estimate stock composition of chum salmon in mixed-stock fisheries. The genetic differentiation index (FST) over all populations and loci was 0.016, with individual locus values ranging from 0.006 to 0.059. Sixteen regional stocks were defined in British Columbia for stock identification applications. Analysis of simulated fishery samples suggested that accurate and precise regional estimates of stock composition should be produced when the microsatellites were used to estimate stock compositions. The main stocks that constitute the October 2007 samples of migrating chum salmon through Johnstone Strait in southern British Columbia were Fraser River (45%–64%), southern British Columbia mainland (22%), and east coast Vancouver Island (13%–28%), within the range of those to be expected in samples from Johnstone Strait. Microsatellites have the ability to provide fine-scale resolution of stock composition in British Columbia coastal fisheries.



1994 ◽  
Vol 51 (S1) ◽  
pp. 50-64 ◽  
Author(s):  
C. M. Kondzela ◽  
C. M. Guthrie ◽  
S. L. Hawkins ◽  
C. d. Russell ◽  
J. H. Helle ◽  
...  

Allozymes from 46 loci were analyzed from chum salmon (Oncorhynchus keta) collected at 61 locations in southeast Alaska and northern British Columbia. Of the 42 variable loci, 21 had a common allele frequency <0.95. We observed significant heterogeneity within and among six regional groups: central southeast Alaska, Prince of Wales Island area, southern southeast Alaska – northern British Columbia, north-central British Columbia, and two groups in the Queen Charlotte Islands. Genetic variation among regions was significantly greater than within regions. The three island groups were distinct from each other and from the mainland populations. Allele frequencies were stable over time in 14 of 15 locations sampled for more than 1 yr. The geographic basis for heterogeneity among regions is confounded in part by spawning-time differences. The Prince of Wales and Queen Charlotte populations spawn in the fall; the mainland populations spawn mainly in the summer, although some overlap exists. Overall, most genetic diversity (97%) occurred within sampling locations; the remaining diversity was distributed almost equally within and among regions. Our genetic data may provide fishery managers a means to estimate stock composition in the mixed-stock fisheries near this boundary between the United States and Canada.







1985 ◽  
Vol 42 (3) ◽  
pp. 437-448 ◽  
Author(s):  
Terry D. Beacham ◽  
Ruth E. Withler ◽  
Allan P. Gould

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.



1982 ◽  
Vol 60 (6) ◽  
pp. 1463-1469 ◽  
Author(s):  
Terry D. Beacham

Significant regional and annual variability in fecundity of coho salmon (Oncorhynchus kisutch) and chum salmon (O. keta) in British Columbia was detected during this investigation. A Kodiak Island (Alaska) coho salmon stock was more fecund than southern stocks in British Columbia and Washington. Fecundity ranged from 2450 to 2850 eggs per female at 53.6 cm postorbital–hypural length for Vancouver Island stocks to over 4400 eggs per female for a Kodiak Island stock at the same length. Chum stocks on Vancouver Island and the Queen Charlotte Islands generally had fecundities less than 3200 eggs per female at 58.8 cm postorbital–hypural length, whereas chum of equal lengths in mainland British Columbia stocks ranged from 3200 to 3450 eggs per female. Older chum and coho were usually more fecund than younger ones, but this difference could be accounted for by differences in mean length-at-age, fecundity being related to body size.



1977 ◽  
Vol 34 (9) ◽  
pp. 1431-1435 ◽  
Author(s):  
E. Bilinski ◽  
R. E. E. Jonas ◽  
Y. C. Lau ◽  
G. Gibbard

Freshly caught chum salmon, Oncorhynchus keta, were stored in ice or refrigerated seawater for 0.3 and 10 days and were then gutted and frozen at two different rates (1 or 14.5 h through the temperature range of 0 to −5 °C). The amount of thaw drip (TD) was determined in steaks following 1.5, 4, 8, and 12 mo of storage at −28 °C. A significant increase in TD occurred with the slow freezing rate or with a delay before freezing. These effects were not suppressed by a prolonged frozen storage, which also produced an increase in TD. There was no marked difference between fish held in ice and refrigerated seawater before freezing. Similar results were obtained with coho salmon, O. kisutch, frozen without prior chill stowage. Key words: Pacific salmon, thaw drip, chill stowage, freezing rates Oncorhynchus keta, O. kisutch



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