Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

Walleye stocks in Nipigon Bay of Lake Superior were homogeneous with those in tributary inland waters but were discrete from Black Bay stocks. Returns from 2200 tagged walleyes in Lake Superior and tributary inland waters between 1955 and 1958 varied from 7.8 to 31.0% for 2 years after release. The commercial fishery in Lake Superior recovered 64.9% of the tags, the sports fishery in inland waters captured 27.6%. Fish tagged in the Nipigon River travelled a mean distance of 11.8 miles from the point of release and were recovered in 191 days (average). Total mortality rates for Nipigon Bay walleyes were 55.0% (1955–57). Mature walleyes on the spawning grounds in the Nipigon River in 1957 were estimated at 22,000, and fish in Nipigon Bay over 14 inches (total length) the same year at 41,000. All male walleyes were mature at 15 inches and females at 18 inches. Walleyes exploitation rates increased with the decline of the lake trout fishery. Wounding and scarring rates by sea lampreys increased during 1955–57 but never exceeded 1.0% on adult walleyes. Severe pollution on the west side of Nipigon Bay originated from a kraft mill. High concentrations of total solids and dense sedimentation of wood fibres created an environment unfavourable to Hexagenia limbata and Pontoporeia affinis. The recent elimination of the walleye fishery in Nipigon Bay is most likely attributable to industrial pollution rather than to overexploitation or sea lamprey predation.

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Occurrence of the eyefluke, Diplostomum (Diplostomum) baeri bucculentum Dubois et Rausch, 1948, in salmonid fishes of northern British Columbia

Canadian Journal of Zoology ◽

10.1139/z85-060 ◽

1985 ◽

Vol 63 (2) ◽

pp. 396-399 ◽

Cited By ~ 4

Author(s):

Hilda Lei Ching

Keyword(s):

Rainbow Trout ◽

Chinook Salmon ◽

Sockeye Salmon ◽

Lake Trout ◽

Infected Fish ◽

Salmo Gairdneri ◽

Coregonus Clupeaformis ◽

Lake Whitefish ◽

Dolly Varden Salvelinus Malma ◽

Prosopium Williamsoni

As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.

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Survey of the Genetic Variation Among Eastern Lake Superior Lake Trout (Salvelinus namaycush)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f81-222 ◽

1981 ◽

Vol 38 (12) ◽

pp. 1738-1746 ◽

Cited By ~ 24

Author(s):

Terrence R. Dehring ◽

Anne F. Brown ◽

Charles H. Daugherty ◽

Stevan R. Phelps

Keyword(s):

Genetic Variation ◽

Gel Electrophoresis ◽

Lake Trout ◽

Lake Superior ◽

Salvelinus Namaycush ◽

Starch Gel Electrophoresis ◽

Average Heterozygosity ◽

Management Implications ◽

Salmonid Species ◽

Starch Gel

Patterns of genetic variation among lake trout (Salvelinus namaycush) of eastern Lake Superior were examined using starch gel electrophoresis. We used 484 individuals sampled from three areas, representing three morphological types (leans, humpers, and siscowets). Of 50 loci examined, 44 were monomorphic in all groups sampled. Genetic variation occurs at six loci AAT-1,2, MDH-3,4, ME-1, and SOD-1. The average heterozygosity found (H = 0.015) is low relative to other salmonid species. A significant amount of heterogeneity exists among the 10 lake trout samples. These differences are due to variation within as well as between morphological types. The significance and management implications of these data are discussed.Key words: genetic variation, lake trout, Salvelinus namaycush, Lake Superior

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

Canadian Journal of Zoology ◽

10.1139/z95-219 ◽

1995 ◽

Vol 73 (10) ◽

pp. 1860-1877 ◽

Cited By ~ 7

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.

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Temporal Trends and Spatial Variabilities of PCB concentrations in Lake Trout from Lake Superior from 1995 to 2013

10.37099/mtu.dc.etdr/189 ◽

2016 ◽

Author(s):

Hongyi Lin

Keyword(s):

Lake Trout ◽

Lake Superior ◽

Temporal Trends

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

Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology ◽

10.1016/s1532-0456(01)00228-9 ◽

2001 ◽

Vol 130 (2) ◽

pp. 145-162 ◽

Cited By ~ 11

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

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Sea lamprey (Petromyzon marinus) size trends in a salmonid stocking context in Lake Superior

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f05-145 ◽

2005 ◽

Vol 62 (10) ◽

pp. 2354-2361 ◽

Cited By ~ 4

Author(s):

Jeffrey C Jorgensen ◽

James F Kitchell

Keyword(s):

Bayesian Model ◽

Fish Community ◽

Bayesian Model Averaging ◽

Lake Trout ◽

Pacific Salmon ◽

Lake Superior ◽

Petromyzon Marinus ◽

Control Period ◽

Model Averaging ◽

Sea Lamprey

Fish community objectives for Lake Superior call for restoration such that it resembles its historical species composition, to the extent possible, yet allow for supplementation of naturalized Pacific salmonids (Oncorhynchus spp.). To achieve these goals, managers strive to control the sea lamprey (Petromyzon marinus) to levels that cause insignificant (<5%) mortality to host species. While control efforts have been successful, sea lamprey size has increased during the control period. We analyzed long-term sea lamprey size trends and found a significant increase from 1961 to 2003 (F = 36.76, p < 0.001, R2 = 0.473). A local regression revealed two significant size increase periods. We used Bayesian model averaging to find the relationship between sea lamprey size and the stocking of salmonids (lean lake trout (Salvelinus namaycush) and Pacific salmon). Bayesian model averaging identified 91 models, and several regressors were common features in many of the models. Sea lamprey weight was related to stocked lake trout lagged 3, 9, 11, and 13 years, and stocked Pacific salmon lagged 4 years. If sea lampreys can achieve larger sizes attached to Pacific salmonid hosts, and thus inflict more damage, there may be a trade-off for managers in achieving the fish community objectives for Lake Superior.

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