Protozoan and Metazoan Parasites of Fishes from the Headwaters of the Parsnip and McGregor Rivers, British Columbia: A Study of Possible Parasite Transfaunations

1983 ◽  
Vol 40 (10) ◽  
pp. 1676-1684 ◽  
Author(s):  
Hisao P. Arai ◽  
Dwight R. Mudry

Results are presented of a study to determine the possible extent of parasite transfaunation across the Continental Divide as a result of a proposed water diversion in northeastern British Columbia. Fish populations in the headwater areas of the McGregor River (Pacific drainage) and of the Parsnip River (Arctic drainage) were sampled during August–November 1976 and during June–September 1977. Eighty-eight species or higher taxonomic groups of parasites were recovered from 1489 host specimens, representing 13 genera and 20 species of fishes. Eimeria cotti from Cottus cognatus and Rhabdochona zacconis from Catostomus macrocheilus have not been previously recorded from North America. New Canadian records are Chloromyxum granulosum, C. montschadskii, Leptotheca sp., Myxidium macrocheili, Myxobolus aureatus, M. microthecum, Neomyxobolus ophiocephalus, Unicauda crassicauda, and Wardia sp. Twenty-six parasites show disjunct distributions in the study area. Three forms (Ceratomyxa shasta, Cryptobia salmositica, and Haemogregarina irkalukpiki) are identified as posing the greatest threat to the fisheries resources of the immediate area and also to the downstream areas. Based in part on these studies, the British Columbia Hydro and Power Authority, in a public announcement, suspended engineering studies of the proposed diversion.

1956 ◽  
Vol 13 (6) ◽  
pp. 759-789 ◽  
Author(s):  
C. C. Lindsey

New and previously published records are listed for 28 species of freshwater fishes in tributaries of the Mackenzie River in northern British Columbia. Distribution patterns are discussed for all species reaching the continental divide at the Peace River headwaters; some are restricted to one or other side, but 17 species are common to the Peace and Fraser Rivers, suggesting that mountain ranges have served as a check but not an insurmountable obstacle to postglacial expansion. Five species indigenous to the Pacific slope—Catostomus macrocheilus, Richardsonius balteatus, Ptychocheilus oregonense, Mylocheilus caurinum, and Cottus asper—have evidently penetrated to the Peace River in comparatively recent times. Three species—the flathead chub Platygobio gracilis, the trout-perch Percopsis omiscomaycus, and the spoon-head sculpin Cottus ricei—have not previously been recorded from the province. Evidence is presented that subspecific distinctions are invalid in Couesius plumbeus (Agassiz) and Lota lota (Linnaeus). Coregonus coulieri and Hybognathus hankinsoni are reported for the first time from the Mackenzie drainage.


<em>Abstract</em>.—The Hanjiang River is the largest tributary of the Yangtze River and contains Danjiangkou Dam, which forms Danjiangkou Reservoir in the middle and upper reaches of the river. During the past 50 years, fisheries resources have changed significantly in the middle and lower Hanjiang River and in Danjiangkou Reservoir. Spawning grounds for major carps and other commercially important fishes have disappeared. Downstream of Danjiangkou Dam, total egg quantity spawned by major carps and other commercially im portant fishes have decreased while similar measures from small-bodied fishes have increased. Important commercial fishes have experienced delayed spawning times and decreased growth. Overall catches of commercial fishes have decreased downstream of the dam, though increased upstream. Some exotic fishes captured in the Danjiangkou Reservoir were likely escapees from cage-culture fish farms in the reservoir or from land-based fish farms around the reservoir. Changes in fisheries resources were presumed related to reservoir management strategies, which produced a narrower range of year-round water temperatures and caused decreases in seasonal water flow variation downstream, overfishing, and eutrophication in the reservoir. To implement a national water diversion policy in central China, the height of the Danjiangkou Dam was increased 15 m in 2012, which significantly increased the impoundment area of the Danjiangkou Reservoir at the end of 2014. Further changes in fisheries resources can be expected in the future. At the present time, management and conservation strategies for fisheries resources need to be developed to ensure future fisheries sustainability for both the Hanjiang River and the Danjiangkou Reservoir.


2007 ◽  
Vol 44 (4) ◽  
pp. 445-457 ◽  
Author(s):  
Jan M Bednarski ◽  
I Rod Smith

Mapping the surficial geology of the Trutch map area (NTS 94G) provides new data on the timing of continental and montane glaciations along the Foothills of northeastern British Columbia. Striated surfaces on mountain crests were dated to the Late Wisconsinan substage by cosmogenic dating. The striations were produced by eastward-flowing ice emanating from the region of the Continental Divide. This ice was thick enough to cross the main ranges and overtop the Rocky Mountain Foothill summits at 2000 m above sea level (asl). It is argued here that such a flow, unhindered by topography, could only have been produced by the Cordilleran Ice Sheet and not by local cirque glaciation. During this time, the Cordilleran Ice Sheet dispersed limestone and schist erratics of western provenance onto the plains beyond the mountain front. Conversely, the Laurentide Ice Sheet did not reach its western limit in the Foothills until after Cordilleran ice retreated from the area. During its maximum, the Laurentide ice penetrated the mountain valleys up to 17 km west of the mountain front, and deposited crystalline erratics from the Canadian Shield as high as 1588 m asl along the Foothills. In some valleys a smaller montane advance followed the retreat of the Laurentide Ice Sheet.


1967 ◽  
Vol 4 (4) ◽  
pp. 625-632 ◽  
Author(s):  
M. A. Roed ◽  
E. W. Mountjoy ◽  
N. W. Rutter

The Athabasca Valley Erratics Train contains a variety of low- to medium- grade metamorphic rocks, the most abundant of which is talcose schist, with lesser amounts of garnet schist and biotite–quartz schist. This erratics train occurs in and west of the Athabasca Valley west of Edson, Alberta. It is probably a late stage deposit of the same glacier that carried and deposited the Erratics Train, Foothills of Alberta. The metamorphic erratics were incorporated into a glacier that originated in the northern part of the Monashee Mountains and Premier Range of British Columbia. This ice movement is also recorded by numerous U-shaped valleys, which extend across the Continental Divide. Thus, during a brief period in late(?) Wisconsin time, the Cordilleran ice in the Rocky Mountains of the Jasper National Park area was partly derived from west of the Continental Divide and the Rocky Mountain Trench. These data agree with the inferred ice movements shown on the 1958 Glacial Map of Canada.


1994 ◽  
Vol 72 (3) ◽  
pp. 470-495 ◽  
Author(s):  
Rowland M. Shelley

In northwestern North America, the milliped family Nearctodesmidae is comprised of four genera, Nearctodesmus Silvestri, Kepolydesmus Chamberlin, Ergodesmus Chamberlin, and Bistolodesmus, new genus, and six species, N. insulans (Chamberlin), N. cerasinus (Wood), N. salix Chamberlin, K. anderisus Chamberlin, E. compactus Chamberlin, and B. bonikus (Chamberlin). These species occur along the Pacific coast from San Francisco Bay to Prince Rupert, British Columbia, including all offshore island groups, with an eastward extension into Lewis and Clark County, Montana, east of the Continental Divide. An allopatric population of N. insulanus occurs in the Shuswap Highlands of British Columbia, and an allopatric species, E. remingtoni (Hoffman), inhabits caves in western and southern Illinois. The principal taxonomic characters are the number of secondary projections from the gonopodal telopodite, the configuration of the longer of these, and the length and configuration of the distal zone of the acropodite. Polydesmus bonikus is a nearctodesmid and is assigned to the new genus, Bistolodesmus. The following new synonymies are proposed: Jaliscodesmus Hoffman under Sakophallus Chamberlin; J. alticola Hoffman under S. simplex Chamberlin; N. brunnior, N. campicolens, and N. malkini, all by Chamberlin, under N. cerasinus; N. amissus, N. pseustes, N. renigens, N. carli, and N. boydi, all by Chamberlin, and N. olympus and N. cochlearius, both by Causey, under N. insulanus; K. mimus, K. hesperus, and K. pungo, all by Chamberlin, under K. anderisus; and Ectopodesmus cristatus and E. c. dentatus, both by Loomis and Schmitt, under Ergodesmus compactus. Modern diagnoses and illustrations are presented for the family and all northwestern taxa, along with keys to the genera and species of Nearctodesmus. Accounts and gonopod drawings are also presented of Sakophallus and S. simplex Chamberlin in Michoacan and Jalisco, Mexico.


1992 ◽  
Vol 70 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Christoph Steeger ◽  
Hans Esselink ◽  
Ronald C. Ydenberg

We compared the general breeding and feeding ecology of ospreys (Pandion haliaetus) in the Creston and Nelson areas of southeastern British Columbia. In the Creston Valley, ospreys nested atop tall trees surrounding a shallow and productive warm-water marsh. Prey species taken by male ospreys included black bullhead (Ictalurus melas), pumpkinseed (Lepomis gibbosus), and yellow perch (Perca flavescens). In contrast, near Nelson, ospreys nested on man-made structures along the narrow West Arm of Kootenay Lake. Osprey prey species in the Nelson area included longnose sucker (Catostomus catostomus), largescale sucker (Catostomus macrocheilus), and mountain whitefish (Prosopium williamsoni). Prey captured at Nelson were larger and contained significantly more energy than at Creston Valley, and hunting from a perch was used for 26% of all captures. All Creston Valley prey were caught by flight hunting. The strike success of foraging ospreys at Nelson was significantly higher than at Creston, and the net yield of flight hunting was 3 times higher. In spite of these differences, the breeding performance of ospreys in the two areas was very similar. Average clutch size was 2.8, brood size at hatching was 2.0, and the average pair fledged 1.4 young. The nest failure rate did not differ between the two areas. Most clutches were initiated in early May, with Nelson-area ospreys laying, on average, 4–7 days later. Egg volumes were smaller at Nelson (66.6 vs. 69.1 cm3). However, the rate at which nestlings gained mass was significantly greater at Nelson. We discuss reasons why the breeding performance varies so little in spite of the great differences in feeding regime.


1970 ◽  
Vol 27 (6) ◽  
pp. 1154-1158 ◽  
Author(s):  
P. McCart ◽  
Nevin Aspinwall

The spawning habits of the largescale sucker, Catostomus macrocheilus, were studied in the watershed of Stave Lake, British Columbia, during the spring of 1967. Spawning occurs in a variety of physical situations, in the inlet and outlet streams of lakes and on the gravelled lakeshores themselves. Spawning acts were observed during the day in some streams and at night in others. The largescale sucker is a mass spawner, with several males attending a single female. The eggs are deposited on, and beneath, the gravel surface. The spawning act is also described.


2002 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
Jack Wierzchowski ◽  
Mark Heathcott ◽  
Michael D. Flannigan

This study examines the influences of fuel, weather and topography on lightning-caused forest fires in portions of southern British Columbia and Alberta, Canada. The results show a significant difference in lightning and lightning-caused fires east and west of the Continental Divide. In British Columbia, on average there was one fire for every 50 lightning discharges whereas in Alberta there was one fire for every 1400 lightning discharges. Elevation, the distribution of lightning strikes, the Daily Severity Rating (a component of the Canadian Forest Fire Weather Index System) and vegetation composition were identified as primary agents controlling lightning fire occurrence. However, the multivariate analysis does suggest that there are other factors influencing fire occurrence other than the biophysical factors we tested. The implications of the lightning and lightning-ignited fires for land managers are discussed.


1982 ◽  
Vol 60 (7) ◽  
pp. 1607-1611 ◽  
Author(s):  
Stuart A. Harris ◽  
Leslie Hubricht

Extensive collecting and dissecting of live material shows that eight species of Oxyloma occur in southern and western Canada. Oxyloma haydeni is the common species across the Prairies from northern Ontario to southern Alberta. Oxyloma kanabensis occurs west of Edmonton, east of the Continental Divide and north of Sundre, while O. nuttalliana occurs west of the Continental Divide in southern British Columbia. Oxyloma groenlandica is found in the Yukon Territory and in the intermontane valleys in interior British Columbia. Oxyloma hawkinsi occurs sparsely, centred in the Okanagan area, but also persists as a probable remnant of the Hypsithermal interval at Exshaw, Alberta. Oxyloma retusa and O. gouldi are confined to the southern portions of Ontario and Quebec.A new species, Oxyloma missoula, occurs in and adjacent to the areas occupied by the former Pluvial Lake Bonneville and Glacial Lake Missoula. All the species could have survived from before the last Wisconsinan ice advance since their distributions straddle the boundary of the glaciated area.


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