Declining Survival of Lake Trout Stocked during 1963–1986 in U.S. Waters 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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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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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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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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Evidence of lake trout (Salvelinus namaycush) spawning and spawning habitat use in the Dog River, Lake Superior

Journal of Great Lakes Research ◽

10.1016/j.jglr.2018.07.017 ◽

2018 ◽

Vol 44 (5) ◽

pp. 1117-1122 ◽

Cited By ~ 2

Author(s):

Nicholas E. Jones ◽

Michael Parna ◽

Sarah Parna ◽

Steve Chong

Keyword(s):

Habitat Use ◽

Lake Trout ◽

Lake Superior ◽

Salvelinus Namaycush ◽

Spawning Habitat

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Geographic morphological variation of siscowet lake trout in Lake Superior based on whole-body morphometries

SIL Proceedings 1922-2010 ◽

10.1080/03680770.1998.11901401 ◽

2000 ◽

Vol 27 (2) ◽

pp. 1062-1062

Author(s):

Seth A. Moore ◽

Charles R. Bronte

Keyword(s):

Morphological Variation ◽

Lake Trout ◽

Lake Superior ◽

Whole Body

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Chlorohydrocarbons in lake superior lake trout (Salvelinus namaycush)

Bulletin of Environmental Contamination and Toxicology ◽

10.1007/bf01705516 ◽

1975 ◽

Vol 14 (4) ◽

pp. 480-488 ◽

Cited By ~ 14

Author(s):

Ronald Parejko ◽

Raymond Johnston ◽

Robert Keller

Keyword(s):

Lake Trout ◽

Lake Superior ◽

Salvelinus Namaycush

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Physical Characteristics and Chemical Composition of Two Subspecies of Lake Trout

Journal of the Fisheries Research Board of Canada ◽

10.1139/f62-002 ◽

1962 ◽

Vol 19 (1) ◽

pp. 39-44 ◽

Cited By ~ 22

Author(s):

Claude E. Thurston

Keyword(s):

Chemical Composition ◽

Oil Content ◽

Lake Trout ◽

Lake Superior ◽

Physical Characteristics ◽

Deep Waters

Trout taken from deep waters of Lake Superior are of two subspecies—a fat one and a lean one—that vary greatly from each other in physical characteristics and in chemical composition. The fat species has a smaller head, larger body, and lighter colour. The percentage of oil does not reach 20% in the fillets of the lean species, whereas it may reach 67% in fillets of the fat species, which has the highest known oil content of any fish.

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