A Note on Two Stocks of Steelhead Trout (Salmo gairdneri) in Capilano River, British Columbia

1960 ◽  
Vol 17 (5) ◽  
pp. 739-742 ◽  
Author(s):  
S. B. Smith

not available


1987 ◽  
Vol 44 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Jeremy M. B. Hume ◽  
Eric A. Parkinson

In a coastal British Columbia stream a stocking density of between 0.3 and 0.7 fry/m2 maximized the production of steelhead trout (Salmo gairdneri) parr and smolts. A severe autumn flood doubled the mortality rates of fry stocked at densities of 0.7 fry/m2 or higher but had little effect on fry stocked at lower densities (<0.15 fry/m2). Overall survival to smolts appeared to be lower than measured elsewhere for wild fish (2 vs. 4.5 – 18%). The proportion (<10%) of surviving fry found below the stocked sections was considered to be an indicator of potential displacement mortality in streams with no vacant downstream areas. This downstream dispersal was not density dependent and was small in comparison with the mortality of nondispersing fish. Although initial fry and parr sizes were density dependent, there was no detectable density effect on older parr or smolt sizes.



1984 ◽  
Vol 41 (10) ◽  
pp. 1412-1420 ◽  
Author(s):  
Eric A. Parkinson

The geographic distributions of biochemical genetic variants at four loci in indigenous British Columbia steelhead (Salmo gairdneri) populations indicated that there was a large-scale subdivision of the species into three major groups. At intermediate geographic scales, gene frequencies were uniform over unexpectedly large areas, but at the smallest geographic scale, significant differentiation was observed between populations in adjacent streams. This pattern of variation supports the view that this species is subdivided into a large number of semi-isolated populations each having the potential to evolve adaptations to local environmental conditions.



1989 ◽  
Vol 67 (2) ◽  
pp. 341-342 ◽  
Author(s):  
Z. Kabata ◽  
D. J. Whitaker

An examination of the cardiac muscle of returning adults of all species of British Columbia Pacific salmonids, including steelhead trout (Salmo gairdneri), for infection by the myxozoan parasite Kudoa thyrsites showed that all species but chum (Oncorhynchus keta) and sockeye (Oncorhynchus nerka) are susceptible to infection. The prevalence of observed infection was low. Its intensity was not determined, but the small numbers of spores observed suggest that it was low. The possible causes of these observations are discussed.



1983 ◽  
Vol 61 (9) ◽  
pp. 1991-1994 ◽  
Author(s):  
T. E. McDonald

An examination of 220 chinook salmon (Oncorhynchus tshawytscha), 84 coho salmon (O. kisutch), 145 steelhead trout (Salmo gairdneri), and 21 cutthroat trout (S. clarki) for Ceratomyxa shasta (Myxozoa: Myxosporea) from 16 localities in the Fraser River drainage, British Columbia, showed that at all sites examined these salmonid species were infected, with a prevalence ranging between 11 and 100%. The study concludes that C. shasta, the causative agent of the salmonid disease ceratomyxosis, is widely distributed in the Fraser drainage basin and discusses these results in relation to proposed fish culture in the region.



1989 ◽  
Vol 46 (2) ◽  
pp. 232-242 ◽  
Author(s):  
S. Swales ◽  
C. D. Levings

Off-channel ponds in the upper reaches of the Coldwater River, British Columbia, were major rearing areas for juvenile coho salmon (Oncorhynchus kisutch). Chinook salmon (Oncorhynchus tshawytscha), steelhead trout (Salmo gairdneri), and Dolly Varden char (Salvelinus malma) were generally scarce in the ponds, although they were numerous in the main river. Coho salmon were predominant at "natural" river sites while steelhead trout was the main species at sites with "rip-rap" bank stabilization. Catches of juvenile coho were much lower in the main river than in the ponds where they were the main species, and were more variable in the river. Population density and biomass estimates of juvenile coho in the ponds ranged from 0.100 fish∙m−2 and 1.00 g∙m−2 to 1.00 fish∙m−2 and 5.15 g∙m−2, compared with density estimates of 0.08–0.23 fish∙m−2 in the river. The coho population in the ponds consisted of 0+ and 1+ age-groups in similar proportions, while in the main river the 0+ age-group was much more abundant. The growth rate of coho in the ponds was faster than in the main river, with pond fish reaching mean lengths of 62–79 mm at the end of the first growing season, compared with 53 mm in the main river. Smolt outmigration from the main study pond occurred in late spring with peak outmigration in May and June coinciding with peak river discharge and increasing water temperatures in the main river and pond.



1966 ◽  
Vol 23 (3) ◽  
pp. 365-393 ◽  
Author(s):  
I. L. Withler

Steelhead enter spawning streams in the lower mainland of British Columbia throughout all months. Those ascending streams between November 1 and April 30 are termed "winter steelhead," while "summer steelhead" enter streams between May 1 and September 30. Cheakamus River is exceptional in that initial stream entry of winter steelhead is delayed until April 1, with most fish entering during April and May. Late entry is related to delayed freshet conditions within this stream. Almost twice as many female as male steelhead were angled. Comparison with trapping results suggests that sport fisheries select for females of anadromous rainbow trout populations. Repeat spawning of winter steelhead was found to range from 5.0% for fish from the Seymour River to 31.3% for Cheakamus River. Repeat spawning among summer steelhead ranged from 4.4% (Seymour River) to 6.3% (Coquihalla River). Mean fork lengths of populations of winter and summer steelhead showed little variation (range 26.3–31.0 inches). Winter steelhead from the Cheakamus River were larger than fish from all other populations while summer steelhead from the Coquihalla River had the least mean length. In general, mean fork lengths of winter and summer steelhead were not greatly different, despite the 5–8-month shorter term of saltwater residence of the latter. However, variations in mean lengths of steelhead between different river systems may result from differences in duration of saltwater residence since mean lengths of these populations did increase with longer saltwater residence. Steelhead spent from 1 to 4 years in fresh water and from 1 to 4 years in salt water.Along the Pacific coast from central California to southern British Columbia, timing of initial stream entry showed little variation. Sex ratios were nearly 1:1. Incidence of repeat spawning decreased from south to north. Mean fork lengths of steelhead populations were greater in northern areas where fish spent more years in fresh and more years in salt water.



1976 ◽  
Vol 54 (9) ◽  
pp. 1530-1534 ◽  
Author(s):  
John R. Smith ◽  
Lavern J. Weber

Elevation in pineal hydroxyindole-O-methyltransferase (HIOMT; EC 2.1.1.4) activity in juvenile steelhead trout was associated with the dark portions of three different photoperiods with a sharp increase in pineal HIOMT activity occurring in the first 4 h of darkness. This pattern of activity could be abolished by bilateral enucleation but not by surgical capping of the pineal region. Surgical exposure of the pineal region in blinded fish did not restore HIOMT responses to changes in lighting.





1986 ◽  
Vol 12 (4) ◽  
pp. 304-313 ◽  
Author(s):  
James M. Haynes ◽  
David C. Nettles ◽  
Kevin M. Parnell ◽  
Michael P. Voiland ◽  
Robert A. Olson ◽  
...  


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