Effects of forestry roads on reproductive habitat and exploitation of lake trout (Salvelinus namaycush) in three experimental lakes

2000 ◽  
Vol 57 (S2) ◽  
pp. 97-104 ◽  
Author(s):  
John M Gunn ◽  
Rod Sein
Keyword(s):  
Lake Trout ◽  
Natural Populations ◽  
Fork Length ◽  
Salvelinus Namaycush ◽  
Spawning Habitat ◽  
Trout Population ◽  
Access Road ◽  
Short Term Study ◽  
Opaque Plastic ◽  
Spawning Sites

This study was designed to test the effects of two potential impacts of forest access roads on lake trout (Salvelinus namaycush) lakes in the Boreal Shield ecozone: (i) loss of reproductive habitat through siltation and (ii) increased access and exploitation. During an 9-year study (1991-1999) in Whitepine Lake, access to seven original spawning sites and over 250 alternate spawning sites was progressively removed by covering the substrate with opaque plastic sheeting to simulate siltation. No effects on recruitment of lake trout have yet been detected. Mark-recapture estimates of juvenile (<370 mm fork length) abundance remained high, mean body size did not increase, and emergent alevins continued to be produced from the alternate spawning sites each year. Similar results occurred in a short-term study in Helen Lake. The lack of obvious effects of reproductive habitat loss was in sharp contrast with the rapid and severe effects that fishing pressure exerted on the lake trout population in Michaud Lake where access was improved by construction of a 12-km forest access road. These findings suggest that lake trout can tolerate substantial losses in spawning habitat, but natural populations, particularly in small lakes, must be protected from excessive exploitation.

Evidence of lake trout (Salvelinus namaycush) spawning and spawning habitat use in the Dog River, Lake Superior

2018 ◽  
Vol 44 (5) ◽  
pp. 1117-1122 ◽  
Author(s):  
Nicholas E. Jones ◽  
Michael Parna ◽  
Sarah Parna ◽  
Steve Chong
Keyword(s):  
Habitat Use ◽  
Lake Trout ◽  
Lake Superior ◽  
Salvelinus Namaycush ◽  
Spawning Habitat

A Niche Definition for Lake Trout (Salvelinus namaycush) and Its Use to Identify Populations at Risk

1994 ◽  
Vol 51 (11) ◽  
pp. 2513-2519 ◽  
Author(s):  
Phil A. Ryan ◽  
Terry R. Marshall
Keyword(s):  
Oxygen Content ◽  
Lake Trout ◽  
Cold Water ◽  
Natural Populations ◽  
Oxygen Demand ◽  
Oxygen Depletion ◽  
Salvelinus Namaycush ◽  
Phosphorus Concentration ◽  
Suitable Habitat ◽  
Populations At Risk

Lake trout (Salvelinus namaycush) populations require cold water with high dissolved oxygen content for survival. We developed models that predict the availability of such habitat, using lake mean depth, which describes both the thermal regime and the initial oxygen reserves, and using a measure of primary productivity, which defines the subsequent oxygen demand of the sediments and water column. Measures of primary production include either phosphorus concentration, chlorophyll a concentration, or Secchi disk transparency. The models are presented as a series of seasonal oxygen depletion isopleths that predict the extent to which the oxygen content of thermally suitable habitat is lost during the period of thermal stratification. The presence or absence of native lake trout in lakes of northwestern Ontario superimposed on these graphs indicated that natural populations seldom occur in lakes in which the seasonal oxygen depletion exceeds 40%. This isopleth is a niche boundary in its representation of adverse temperature and oxygen conditions for lake trout. The delineation of this boundary permits the identification of lakes where lake trout populations could be seriously affected by cultural eutrophication, overfishing, or climate warming.

Identification of lake trout Salvelinus namaycush spawning habitat in northern Lake Huron using high-resolution satellite imagery

2016 ◽  
Vol 42 (1) ◽  
pp. 127-135 ◽  
Author(s):  
Amanda G. Grimm ◽  
Colin N. Brooks ◽  
Thomas R. Binder ◽  
Stephen C. Riley ◽  
Steven A. Farha ◽  
...  
Keyword(s):  
High Resolution ◽  
Satellite Imagery ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Lake Huron ◽  
Spawning Habitat ◽  
High Resolution Satellite Imagery

Predation by Freshwater Seals on the Fish Community of Lower Seal Lake, Quebec

1978 ◽  
Vol 35 (6) ◽  
pp. 844-850 ◽  
Author(s):  
G. Power ◽  
Jean Gregoire
Keyword(s):  
Brook Trout ◽  
Fish Community ◽  
Lake Trout ◽  
Fork Length ◽  
Salvelinus Namaycush ◽  
Phoca Vitulina ◽  
Unit Weight ◽  
Potential Yield ◽  
Spawning Period ◽  
Show Evidence

The presence of freshwater harbor seals (Phoca vitulina) in Lower Seal Lake, Quebec, has drastically modified the lake's fish community. Lake trout (Salvelinus namaycush) are the most affected; they are small (rarely exceed 55 cm fork length), their growth rate is faster than in neighboring lakes, their longevity is greatly reduced, the age at sexual maturity has been halved, and individual fecundity per unit weight has increased at the expense of egg diameter. Brook trout (S. fontinalis), the dominant fish species in the lake, show evidence of high mortality rates in the lake, but are protected during the vulnerable spawning period because their spawning sites are dispersed in tributary streams. Rough calculation suggests the seal population is small and that it consumes the lake's potential yield of fish annually. Key words: predation, freshwater seals, Phoca vitulina, Salvelinus namaycush, Salvelinus fontinalis

Genetic Differences in Retention of Swimbladder Gas Between Two Populations of Lake Trout (Salvelinus namaycush)

1974 ◽  
Vol 31 (8) ◽  
pp. 1351-1354 ◽  
Author(s):  
P. Ihssen ◽  
J. S. Tait
Keyword(s):  
Brook Trout ◽  
Depth Distribution ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Genetic Differences ◽  
Trout Population ◽  
Two Populations

Lake trout (Salvelinus namaycush) derived from two populations differed in retention of swimbladder gas. The two reciprocal interpopulation crosses were intermediate to the parent populations. The two F1 hybrids obtained by crossing fish from each lake trout population with brook trout (S. fontinalis) were also found different in retention. Gas retention was correlated with depth distribution of the parent populations, high retention being associated with deeper distribution.

Lake Trout (Salvelinus namaycush) Growth Potential Predicted from Cisco (Coregonus artedii) Population Structure and Conductivity

1989 ◽  
Vol 46 (9) ◽  
pp. 1531-1538 ◽  
Author(s):  
Edward A. Trippel ◽  
F. William H. Beamish
Keyword(s):  
Lake Trout ◽  
Fork Length ◽  
Growth Efficiency ◽  
Salvelinus Namaycush ◽  
Growth Potential ◽  
Food Sources ◽  
Stepwise Multiple Regression ◽  
Order Of Magnitude ◽  
Mean Size ◽  
Coregonus Artedii

Trophic dynamics between lake trout (Salvelinus namaycush) and cisco (Coregonus artedii) were examined in a set of 10 northwestern Ontario lakes that ranged in conductivity by nearly an order of magnitude. Diets revealed the possibility of interspecific competition for invertebrate prey prior to initiation of piscivory by lake trout at approximately 200 mm fork length (FL). Von Bertalanffy growth equations (based on otolith ages) were used to estimate time to attain this length (1.4–3.0 yr). Contrary to anticipated results, lake trout reached this size more rapidly in lakes with high cisco abundance. Presumably, this relationship was caused by improved food conditions for young trout in some of the more productive waterbodies. However, after removing the collinearity between lake conductivity and nonpiscivorous growth by regression analysis, there was no relationship between the time for lake trout to reach 200 mm and cisco abundance. Piscivorous growth varied (L∞ = 508 to 740 mm) extensively among the 10 populations and was likely a function of growth efficiency from different food sources. Using stepwise multiple regression, 81% of the L∞ variation among lakes was explained by cisco abundance and mean size. Linear regression between L∞ and mean size of trout (but not trout abundance) on conductivity generated significant positive relationships.

Limnological and Biological Observations in the Region of the Ungava or Chubb Crater, Province of Quebec

1955 ◽  
Vol 12 (4) ◽  
pp. 487-498 ◽  
Author(s):  
N. V. Martin
Keyword(s):  
Deep Water ◽  
Vascular Plants ◽  
Crater Lake ◽  
Lake Trout ◽  
Salvelinus Alpinus ◽  
Fork Length ◽  
Salvelinus Namaycush ◽  
Surface Oxygen ◽  
Secchi Disc ◽  
Total Solids

Ungava Crater Lake, at 73° 41′ W.L. and 61° 17′ N.L., lies in a meteoritic crater of the northern Quebec tundra. The lake is nearly circular, 1.7 miles in diameter, with steep walls and a maximum known depth of 825 feet. Secchi disc transparency was 35 metres. Summer surface temperatures were 3–4 °C., of the deep water a little less. Surface oxygen was abundant, pH was 6.5–6.6. Total solids in the water were less than 20 parts per million, and hardness was only 1.7 p.p.m. Three kinds of mammals and 14 of birds were found in the crater region. Arctic char, Salvelinus alpinus, were the only fish taken in the crater lake. Specimens up to 21.8 inches fork length and 18 years old were taken; they fed on insects and other char. Char in other nearby waters grew somewhat faster but ate the same foods; mature females as small as 4.0 inches were seen. Lake trout, Salvelinus namaycush, in a lake near the crater reached 33.5 inches and 15.8 pounds. Growth was very slow, the greatest age determined being 21 years, at 13 pounds. Twenty-nine species of vascular plants were collected close to the crater.

The White Sucker Population of South Bay, Lake Huron, and Effects of the Sea Lamprey on It

1967 ◽  
Vol 24 (10) ◽  
pp. 2117-2136 ◽  
Author(s):  
Daniel W. Coble
Keyword(s):  
Lake Trout ◽  
Fork Length ◽  
Size Composition ◽  
Sea Lamprey ◽  
Lake Huron ◽  
Minimal Distance ◽  
Alosa Pseudoharengus ◽  
White Sucker ◽  
Trout Population ◽  
Relationship Of

Information on ecology and dynamics of white suckers, Catostomus commersoni (Lacépède), in South Bay, Lake Huron, was obtained from experimental fishing over more than a decade and from a tagging program in 1955 and 1956. (A total of 1667 suckers were tagged and 8% of them were subsequently recovered.) The fish moved about extensively in the bay, minimal distance travelled averaging 3.8 km during a summer. Nevertheless, it was necessary to divide the bay into discrete fishing areas for calculating population and mortality estimates. The length–weight relationship of adult suckers in June was W = 5.883 × 10−4 L2.92262; where W is weight in pounds and L is fork length in inches. Growth averaged only about 7.6 mm/year, and an annulus was not formed on the scales every year. In 1956 the population may have amounted to about 160,000 adult white suckers, or 23 fish per hectare or 17.5 kg/hectare, for the part of the bay less than 36 m deep. The exploitation rate appeared to be less than 2%. The annual survival rate of suckers larger than approximately 38 cm appeared to be about 70–75% decreasing with size of fish. Although it is not known if the size of the population has changed, the size composition changed between 1953 and 1964 through the loss of larger fish. Marked changes in the fauna of South Bay subsequent to the late 1940's include the invasion of the sea lamprey, Petromyzon marinus Linnaeus, and the alewife, Alosa pseudoharengus (Wilson), the disappearance of the lake trout, Salvelinus namaycush (Walbaum), and the decline of the population of the cisco, Coregonus (= Leucichthys) artedii LeSueur. The loss of the larger fish in the white sucker population was probably caused by the sea lamprey, for it occurred after the destruction of the lake trout population and corresponded with increased incidence of lamprey scarring of suckers.

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