Ecology of Arctic Populations of Lake Trout, Salvelinus namaycush, Lake Whitefish, Coregonus clupeaformis, Arctic Char, S. alpinus, and Associated Species in Unexploited Lakes of the Canadian Northwest Territories

1976 ◽  
Vol 33 (11) ◽  
pp. 2459-2488 ◽  
Author(s):  
Lionel Johnson
Keyword(s):  
Northwest Territories ◽  
Lake Trout ◽  
Length Distribution ◽  
Salvelinus Namaycush ◽  
Hudson Bay ◽  
Coregonus Clupeaformis ◽  
The West ◽  
Bear Lake ◽  
Incoming Energy ◽  
Associated Species

The available data on the fish populations of 35 lakes in the Northwest Territories are examined. The lakes range in size from Great Bear Lake (31, 156 km2) to Keyhole Lake (46 ha); they are situated between lat. 60 and 75° N, east from the Mackenzie River to the west coast of Hudson Bay. Lake trout (Salvelinus namaycush) and whitefish (Coregonus clupeaformis) form the main populations of the mainland lakes and together make up to 95% of the total catch. There is a trend toward increasing importance of whitefish with decreasing severity of conditions. Most populations show a uni, bi-, or trimodal length distribution; age distributions are unimodal. No change in these distributions was observed over a large number of years in certain lakes. These populations are considered to have reached a climax condition comparable with a vegetational climax, and are therefore in equilibrium with their environment. All incoming energy is ultimately used in respiration to support a high biomass of fish.

scholarly journals Microsatellite and mtDNA analysis of lake trout,Salvelinus namaycush, from Great Bear Lake, Northwest Territories: impacts of historical and contemporary evolutionary forces on Arctic ecosystems

2013 ◽  
Vol 3 (1) ◽  
pp. 145-161 ◽  
Author(s):  
Les N. Harris ◽  
Kimberly L. Howland ◽  
Matthew W. Kowalchuk ◽  
Robert Bajno ◽  
Melissa M. Lindsay ◽  
...  
Keyword(s):  
Northwest Territories ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Arctic Ecosystems ◽  
Evolutionary Forces ◽  
Bear Lake

Changes in fish populations affected by the construction of the La Grande complex (Phase I), James Bay region, Quebec

1995 ◽  
Vol 73 (10) ◽  
pp. 1860-1877 ◽  
Author(s):  
Jean-Claude DesLandes ◽  
Sylvie Guénette ◽  
Yves Prairie ◽  
Réjean Fortin ◽  
Dominique Roy ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Time Intervals ◽  
Complex Phase ◽  
Coregonus Artedii ◽  
Secondary Productivity ◽  
Longnose Sucker ◽  
The Impact

Catches per unit of effort (CPUE) with experimental gill nets, recruitment, growth, and condition were monitored between 1977 and 1992 to evaluate the impact of impoundment on the main fish species of La Grande 2, Opinaca, and Caniapiscau reservoirs and the Boyd–Sakami diversion. CPUE and recruitment of northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis) increased markedly at most stations after impoundment and decreased at the end of the series. The lake whitefish and cisco (Coregonus artedii) showed their most striking rise in CPUE at two bay stations of La Grande 2 and Opinaca reservoirs. CPUE and recruitment of the longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), and lake trout (Salvelinus namaycush) (Caniapiscau) showed a general decrease following impoundment. CPUE for the walleye (Stizostedion vitreum) also decreased at several stations; however, the two most southerly stations in La Grande 2 reservoir and the Boyd–Sakami station showed high CPUE during the series. Concentration–redistribution phenomena explain part of the observed variations in CPUE. Correlation analyses showed that walleyes and white suckers were attracted to the warmer, more turbid stations, and that the high primary and secondary productivity of bay stations attracted the coregonines. Growth and condition of the main species increased during variable time intervals after impoundment and decreased at the end of the series.

Accumulation, distribution and toxicology of dietary nickel in lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush)

2001 ◽  
Vol 130 (2) ◽  
pp. 145-162 ◽  
Author(s):  
M.D Ptashynski ◽  
R.M Pedlar ◽  
R.E Evans ◽  
K.G Wautier ◽  
C.L Baron ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish

Fecundity Changes in Exploited Populations of Lake Whitefish (Coregonus clupeaformis) and Lake Trout (Salvelinus namaycush)

1978 ◽  
Vol 35 (7) ◽  
pp. 945-950 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Key Words ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Northern Canada ◽  
Average Fecundity ◽  
Individual Fecundity

This report considers the possibility that exploited populations of lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush) may show increased individual fecundity. Average fecundity of both species in three exploited lakes varied significantly between 1972 and 1976, while fecundity in an adjacent unexploited lake did not vary. Changes in the fecundity of whitefish and trout in the exploited lakes were not clearly related to the pattern and intensity of exploitation, but fecundity of both species increased in all exploited lakes after exploitation, with trout showing the greater response. Key words: fecundity, lake whitefish, lake trout, exploitation, northern Canada

Long-Term Effects of Diet on the Biology of the Lake Trout and the Fishery in Lake Opeongo, Ontario

1970 ◽  
Vol 27 (1) ◽  
pp. 125-146 ◽  
Author(s):  
N. V. Martin
Keyword(s):  
Lake Trout ◽  
Feeding Activity ◽  
Salvelinus Namaycush ◽  
Point Of View ◽  
Average Weight ◽  
Coregonus Clupeaformis ◽  
Long Term Effects ◽  
Food Content ◽  
Coregonus Artedii

From 1936 to 1965 food content was examined in 17,171 Lake Opeongo lake trout (Salvelinus namaycush). The diet is analysed from the point of view of frequency of occurrence of foods, their weight, feeding activity of trout, size of trout and size of food, and seasonal and annual changes in food habits.In the late 1940's and early 1950's perch, Perca flavescens, largely disappeared from the diet. The lake trout initially turned to lake whitefish, Coregonus clupeaformis, and then to the cisco, Coregonus artedii, introduced into Lake Opeongo in 1948.As a result of these dietary changes lake trout are now heavier and rate of growth has improved. Age and size at maturity is later and there are fewer infertile fish. Egg counts, egg size, and ovary weights are now greater, particularly in the medium-sized lake trout.In the fishery the average weight of individual trout taken has almost doubled. About 25% more of the immature stock is exploited by the recent fishery. The harvest and catchability of lake trout has remained generally constant on a numerical basis but show an improvement on a poundage basis in the more recent years. The possible effects of these changes on the character of the fishery are discussed.

Distribution of Fish Species in Great Bear Lake, Northwest Territories, with Reference to Zooplankton, Benthic Invertebrates, and Environmental Conditions

1975 ◽  
Vol 32 (11) ◽  
pp. 1989-2004 ◽  
Author(s):  
Lionel Johnson
Keyword(s):  
Benthic Invertebrates ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Benthic Organisms ◽  
Mysis Relicta ◽  
Bear Lake ◽  
Bear River ◽  
Couesius Plumbeus ◽  
High Degree ◽  
Distribution Of Fish

Benthic invertebrates in Great Bear Lake are most highly concentrated in the upper 20 m. Densities between 20 and 100 m are low; below 100 m only Mysis relicta and Myoxocephalus quadricornis exist at measurable densities. All benthic organisms exhibit a high degree of patchiness.Lake trout, Salvelinus namaycush, and M. quadricornis are two species that inhabit the lake at all depths (3–400 m) and temperatures (13.2 C for M. quadricornis and 15 C for S. namaycush).Whitefish, Coregonus clupeaformis, inhabit only the bays, seldom being caught in water over 20 m deep. The distribution of whitefish is considered to be restricted mainly by the density of benthic organisms.Three species are confined to the periphery of the lake, Stizostedion vitreum, Lota lota, and Catostomus catostomus. Two species, Couesius plumbeus and Percopsis omiscomaycus, are present in the headwaters and Great Bear River but have not been able to establish themselves in Great Bear Lake. Extreme oligotrophy is considered to have had the effect of reducing species diversity.

Fine-scale population structure in lake trout (Salvelinus namaycush) influenced by life history variation in the Husky Lakes drainage basin, Northwest Territories, Canada

2018 ◽  
Vol 75 (7) ◽  
pp. 1070-1081 ◽  
Author(s):  
Benjamin C. Kissinger ◽  
Les N. Harris ◽  
Danny Swainson ◽  
W. Gary Anderson ◽  
Margaret F. Docker ◽  
...  
Keyword(s):  
Life History ◽  
Northwest Territories ◽  
Brackish Water ◽  
Life Histories ◽  
Lake Trout ◽  
Drainage Basin ◽  
Salvelinus Namaycush ◽  
Life History Variation ◽  
Genetic Structuring ◽  
Nonbreeding Season

Partial anadromy is common within salmonid populations, where resident and anadromous individuals interbreed and overlap in habitat use during portions of life. Deviation to this definition occurs within the Husky Lakes drainage basin (HLDB), Northwest Territories, where freshwater resident, semi-anadromous, and brackish-water resident lake trout (Salvelinus namaycush) life history types are documented. In this study, microsatellite DNA variation was assayed to evaluate genetic structuring among life history types from the HLDB and adjacent lower Mackenzie River system. Significant differentiation was resolved among most locations and life histories (global FST = 0.192). Brackish-water residents were differentiated from all locations and life histories, including sympatric semi-anadromous individuals, providing evidence for genetically fixed strategies. Also, this provides the first evidence of breeding partial migration in salmonids using brackish-water environments, where brackish-water residents and semi-anadromous migrants interact during the nonbreeding season, but the latter migrate elsewhere to spawn. Alternatively, the lack of genetic differentiation between semi-anadromous and Sitidgi Lake residents suggests conditional mating tactics may also influence partial anadromy. This work provides novel insights into partial anadromy in Arctic salmonids and expands our knowledge of biodiversity in this region.

scholarly journals Age estimation comparison between whole and thin-sectioned otoliths and pelvic fin-ray sections of long-lived lake trout, Salvelinus namaycush, from Great Bear Lake, Northwest Territories, Canada

Polar Biology ◽  
2021 ◽  
Author(s):  
Colin P. Gallagher ◽  
Rick J. Wastle ◽  
Julie R. Marentette ◽  
Louise Chavarie ◽  
Kimberly L. Howland
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Bear Lake ◽  
Management Objectives ◽  
Younger Age ◽  
Fin Ray ◽  
Fin Rays ◽  
Different Levels ◽  
Age Estimates ◽  
Pelvic Fin

AbstractStudies to determine precision and bias of both methods and age-readers are important to evaluate reliability of age data used for developing fisheries management objectives. We assessed within-reader, between-reader, and between-method precision (coefficient of variation, CV%) and bias of age estimations for long-lived lake trout, Salvelinus namaycush, from Great Bear Lake using three readers with different levels of experience. The assessment used independent age estimates (n = 3 per reader) from whole and transverse-sectioned otoliths (range = 1–67 years), and pelvic fin-ray sections (range = 3–26 years). We also examined between-method differences in assigned confidence scores. Within readers, age estimates from sectioned otoliths were more precise (2.6–3.0%) than whole (3.6–4.5%) otoliths. Between whole and sectioned otoliths, precision of age estimates was 5.4% and bias was low up to age 20. Age was typically under-estimated from whole otoliths compared to sections for fish ≥ 34 years. Increased reader confidence was correlated with greater precision and younger age estimates, particularly for whole otoliths, but less so for fin rays. Age was estimated with higher confidence from otolith sections than other methods. The least experienced reader estimated age with the lowest precision, and between-reader bias was evident among older ages. Age was consistently under-estimated and less precise from pelvic fins compared to sectioned otoliths, and are therefore an unsuitable non-lethal alternative. Sectioned otoliths revealed longevity was greater (67 years) than historically documented using whole otoliths (53 years) for these fish. Our findings contribute to those relying on otoliths or pelvic fin rays to estimate ages of long-lived lake trout populations, which are a key component of freshwater fauna in polar North America.

scholarly journals Genome Sequences of Shewanella baltica and Shewanella morhuae Strains Isolated from the Gastrointestinal Tract of Freshwater Fish

2018 ◽  
Vol 6 (25) ◽  
Author(s):  
Daniel Castillo ◽  
Lone Gram ◽  
Frank E. Dailey
Keyword(s):  
Gastrointestinal Tract ◽  
Freshwater Fish ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Genome Sequences ◽  
Content Type ◽  
Niche Adaptation ◽  
Specific Species ◽  
Shewanella Baltica

ABSTRACT We present here the genome sequences of Shewanella baltica strain CW2 and Shewanella morhuae strain CW7, isolated from the gastrointestinal tract of Salvelinus namaycush (lean lake trout) and Coregonus clupeaformis (whitefish), respectively. These genome sequences provide insights into the niche adaptation of these specific species in freshwater systems.

Sign in / Sign up

Export Citation Format

Share Document