Impacts of road access on lake trout (Salvelinus namaycush) populations: regional scale effects of overexploitation and the introduction of smallmouth bass (Micropterus dolomieu)

2009 ◽  
Vol 66 (2) ◽  
pp. 212-223 ◽  
Author(s):  
Scott D. Kaufman ◽  
Ed Snucins ◽  
John M. Gunn ◽  
Wayne Selinger
Keyword(s):  
Lake Trout ◽  
Scale Effects ◽  
Regional Scale ◽  
Winter Season ◽  
Salvelinus Namaycush ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Excessive Pressure ◽  
Fishing Activity ◽  
Remote Lakes

In lake trout ( Salvelinus namaycush ) lakes of northeastern Ontario, Canada, aerial surveys of fishing activity on individual lakes (N = 589) and quantitative gillnet surveys (N = 65) were used to assess the effects of road access on angling effort and the presence of introduced smallmouth bass ( Micropterus dolomieu ). Angling effort, particularly during the open-water season, was highest and often exceeded estimated sustainable levels on lakes with good road access. Approximately 25% of the remote lakes also received excessive pressure during the winter season. Angler numerical responses to lake trout abundance were detected in remote lakes, but not in road-accessible lakes. Smallmouth bass were more prevalent in lakes with road access and human settlement (either cottages or lodges), supporting the theory that they were introduced into these lakes. Lake trout populations were depleted throughout much of the study range. Even without road access or smallmouth bass, lake trout abundance was still 47% lower than in unexploited reference lakes. When bass and (or) road access were present, lake trout abundance decreased by 77%. Remote lake trout populations in this area are clearly vulnerable to the negative impacts of improved access, a vector for both overexploitation and species introductions.

Estimated Impacts of SO2 Emissions from Sudbury Smelters on Ontario's Sportfish Populations

1992 ◽  
Vol 49 (S1) ◽  
pp. 87-94 ◽  
Author(s):  
John E. Matuszek ◽  
Donna L. Wales ◽  
John M. Gunn
Keyword(s):  
Water Quality ◽  
Brook Trout ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Quality Improvements ◽  
So2 Emissions ◽  
Acidic Lakes ◽  
Local Impacts

Impacts of acidification on the major sportfish species in Ontario (lake trout (Salvelinus namaycush), brook trout (S. fontinalis), smallmouth bass (Micropterus dolomieu), and walleye (Stizostedion vitreum)) were estimated from the results of extensive water quality surveys conducted during the period 1978–85. Local impacts, within the 17 000 km2 area most affected by emissions from Sudbury smelters, were also estimated and compared with the provincial values. The estimated numbers of acidic lakes in Ontario in which viable sportfish populations have disappeared were 119 lake trout lakes (5.1% of known lake trout lakes), 34 brook trout lakes (1.6%), 52 smallmouth bass lakes (2.2%), and 14 walleye lakes (0.3%). Most of these affected lakes were in the Sudbury zone, where fish populations, particularly those of lake trout, began declining more than 30 yr ago. The estimated numbers of critically acidic lakes in the Sudbury zone were 94 lake trout lakes, 14 brook trout lakes, 18 smallmouth bass lakes, and 7 walleye lakes. More recent sampling of a subset of Sudbury lakes indicated that substantial water quality improvements have occurred as a result of emission reductions from Sudbury smelters.

Optimal Use of Creel Survey Data in Assessing Population Behaviour: Lake Opeongo Lake Trout (Salvelinus namaycush) and Smallmouth Bass (Micropterus dolomieui), 1936–83

1987 ◽  
Vol 44 (S2) ◽  
pp. s229-s238 ◽  
Author(s):  
B. J. Shuter ◽  
J. E. Matuszek ◽  
H. A. Regier
Keyword(s):  
Lake Trout ◽  
Total Mortality ◽  
Salvelinus Namaycush ◽  
Fish Population ◽  
Smallmouth Bass ◽  
Fishing Mortality ◽  
Assessment Data ◽  
Creel Survey ◽  
Micropterus Dolomieui ◽  
Independent Assessment

Creel survey and independent assessment data on the lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieui) populations of Lake Opeongo were evaluated. Annual estimates of total mortality, fishing mortality, and abundance were generated for each population over the period 1936–83. Large variations in survey efficiency, angler efficiency, fishing mortality, and abundance were identified over this period. We argue that a creel survey, which is expected to provide reliable information on fish population dynamics, requires an overall study design which includes collection of data on the number and relative efficiency of different kinds of anglers and periodic assessment studies aimed at providing independent checks on both survey effectiveness and population behaviour.

Limnological Characteristics of Ontario Lakes in Relation to Associations of Walleye (Stizostedion vitreum vitreum), Northern Pike (Esox lucius), Lake Trout (Salvelinus namaycush), and Smallmouth Bass (Micropterus dolomieui)

1977 ◽  
Vol 34 (10) ◽  
pp. 1592-1601 ◽  
Author(s):  
M. G. Johnson ◽  
J. H. Leach ◽  
C. K. Minns ◽  
C. H. Olver
Keyword(s):  
Lake Trout ◽  
Climatic Factors ◽  
Low Frequency ◽  
Northern Pike ◽  
Esox Lucius ◽  
Salvelinus Namaycush ◽  
Smallmouth Bass ◽  
Stizostedion Vitreum ◽  
Pike Esox Lucius ◽  
Micropterus Dolomieui

Commonest lake types of the 15 combinations of four fish species (walleye, Stizostedion vitreum vitreum; northern pike, Esox lucius; lake trout, Salvelinus namaycush and smallmouth bass, Micropterus dolomieui) were walleye–pike (22%), pike "only" (19%), lake trout "only" (16%) and smallmouth bass "only" (10%). Lake trout–walleye and lake trout–walleye–smallmouth bass types were extremely rare. Lake depth and area were variables of greatest significance in distinguishing lake types by discriminant analysis. Climatic factors explained the general geographic distribution of smallmouth bass. Hypotheses to explain the low frequency of walleye in small lakes include possibilities of (1) low probability of successful coexistence of pike and walleye, (2) lack of wind fetch to clear spawning areas, and (3) "Lebensraum requirement" of the walleye. Key words: limnology, Percidae, methodology, Ontario lake types, Stizostedion vitreum vitreum, Esox lucius, Salvelinus namaycush, Micropterus dolomieui, distribution, associations

Relationship of Mercury Concentrations in Lake Trout (Salvelinus namaycush) and Smallmouth Bass (Micropterus dolomieui) to the Physical and Chemical Characteristics of Ontario Lakes

1989 ◽  
Vol 46 (3) ◽  
pp. 426-434 ◽  
Author(s):  
Michael J. McMurtry ◽  
Donna L. Wales ◽  
Wolfgang A. Scheider ◽  
Gail L. Beggs ◽  
Patricia E. Dimond
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Lake Trout ◽  
Water Hardness ◽  
Salvelinus Namaycush ◽  
Smallmouth Bass ◽  
Stepwise Multiple Regression ◽  
Lake Area ◽  
Micropterus Dolomieui ◽  
The Relationship

Concentrations of mercury in dorsal muscle tissue of lake trout (Salvelinus namaycush) from Ontario lakes were positively correlated with variables indicating lake dystrophy (dissolved organic carbon, colour, iron, transparency) and were also correlated with watershed area and lake area. Stepwise multiple regression selected dissolved organic carbon as the only variable which explained a significant amount of variation (37%) in mercury concentrations in lake trout. The relationship between dissolved organic carbon and mercury appeared to be strongest in the group of lakes with values of dissolved organic carbon less than 4.0 mg∙L−1. In contrast, mercury concentrations in smallmouth bass (Micropterus dolomieui) were correlated with variables reflecting both water hardness (magnesium, calcium, conductivity) and acidity (pH, alkalinity). The relationship was inverse for the water hardness variables and positive for acidity. Stepwise regression identified three variables significant in explaining variation in mercury in smallmouth bass: calcium, dissolved organic carbon, and latitude. Mechanisms that may explain the effects of organic matter, water hardness, and acidity on mercury accumulation by fish are discussed.

scholarly journals Species-specific preferences drive the differential effects of lake factors on fish production

2020 ◽  
Vol 77 (10) ◽  
pp. 1625-1637
Author(s):  
Lauren A. Jarvis ◽  
Bailey C. McMeans ◽  
Henrique Corrêa Giacomini ◽  
Cindy Chu
Keyword(s):  
Lake Trout ◽  
Cold Water ◽  
Secchi Depth ◽  
Regression Tree ◽  
Smallmouth Bass ◽  
Environmental Drivers ◽  
Predatory Fish ◽  
Fish Production ◽  
Micropterus Dolomieu ◽  
Boosted Regression Tree

As the global human population grows, it remains a top priority for communities, managers, policymakers, and stakeholders to maintain healthy, sustainable, and productive fisheries under continued global change. Here we used a dataset consisting of fish and lake characteristics for 536 lakes across Ontario, Canada, to test whether multiple climate, human, and biological factors differentially affect fish production (i.e., population biomass per hectare per year). We tested the hypothesis that temperature is the key driver of fisheries production by testing for the effects of multiple factors on the production of three top predatory fish species: cold-water lake trout (Salvelinus namaycush), cool-water walleye (Sander vitreus), and warm-water smallmouth bass (Micropterus dolomieu). Using boosted regression tree analyses, we found that lake trout production was most influenced by the volume of hypolimnetic habitat, walleye production was related to other climatic variables, and smallmouth bass production was most influenced by sampling day of the year followed by Secchi depth. Our results suggest that current fish production models — that only include temperature and body size — may oversimplify important ecological complexities and thus misinform management decisions because species respond differently to environmental drivers.

Pelagic Food Chain Structure in Ontario Lakes: A Determinant of Mercury Levels in Lake Trout (Salvelinus namaycush)

1994 ◽  
Vol 51 (2) ◽  
pp. 381-389 ◽  
Author(s):  
Gilbert Cabana ◽  
Alain Tremblay ◽  
Jacob Kalff ◽  
Joseph B. Rasmussen
Keyword(s):  
Food Chain ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Chain Structure ◽  
Food Chains ◽  
Micropterus Dolomieu ◽  
Species Introduction ◽  
Mysis Relicta ◽  
Recent Species ◽  
Glacial Relict

The trophic structure of pelagic communities in glaciated regions is highly variable due to restricted dispersal of glacial relict taxa and recent species introduction. Much of the between-lake variation in Hg in lake trout (Salvelinus namaycush) flesh from the St. Lawrence system (non-point-source contaminated lakes), which spans more than two orders of magnitude (0.03–3.96 μg/g), results from differences in the length of pelagic food chains. Hg levels from the longest food chains where pelagic forage fish and the crustacean Mysis relicta were present were about 3.6-fold higher than those from the shortest food chains where these last two trophic components were missing. A lack of correlation between Hg levels in small-mouth bass (Micropterus dolomieu), which do not exploit the pelagic food chain, and the length of the pelagic food chain confirmed that the positive relationship observed in lake trout could not be attributed to the confounding effect of some physicochemical factors covarying with our pelagic food chain classification. Our results confirmed that the food chain biomagnification model developed by Rasmussen et al. (1990. Can. J. Fish. Aquat. Sci. 47: 2030–2038) to predict PCB levels in lake trout can also be applied to Hg biomagnification.

Evidence of successful river spawning by lake trout (Salvelinus namaycush) in the Lower Niagara River, Lake Ontario

2021 ◽  
Author(s):  
Alexander Gatch ◽  
Dimitry Gorsky ◽  
Zy Biesinger ◽  
Eric Bruestle ◽  
Kelley Lee ◽  
...  
Keyword(s):  
Lake Trout ◽  
Lake Ontario ◽  
Salvelinus Namaycush ◽  
Niagara River

An examination of the PCB: lipid relationship among individual fish

1997 ◽  
Vol 54 (5) ◽  
pp. 1031-1038
Author(s):  
C A Stow ◽  
L J Jackson ◽  
J F Amrhein
Keyword(s):  
Salmo Trutta ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Salvelinus Namaycush ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Strong Linear Correlation ◽  
Brown Trout Salmo Trutta ◽  
The Relationship

We examined data from 1984 to 1994 for five species of Lake Michigan salmonids to explore the relationship between total PCB concentration and percent lipid. When we compared mean species lipid and PCB values, we found a strong linear correlation. When we compared values among individuals, we found modest positive PCB:lipid associations in brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and rainbow trout (Oncorhynchus mykiss) collected during spawning, but positive associations were not apparent among nonspawning individuals. Lake trout (Salvelinus namaycush) exhibited no discernible PCB:lipid relationship. Our results are not incompatible with previous observations that contaminants are differentially partitioned into lipids within a fish, but these results do suggest that lipids are not a major factor influencing contaminant uptake.

Classification of Sea Lamprey (Petromyzon marinus) Attack Marks on Great Lakes Lake Trout (Salvelinus namaycush)

1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Petromyzon Marinus ◽  
Attachment Site ◽  
Sea Lamprey ◽  
Salvelinus Namaycush ◽  
Oral Disc ◽  
Field Assessment ◽  
Sea Lampreys

Criteria for the classification of marks inflicted by sea lamprey (Petromyzon marinus) into nine categories were developed from laboratory studies in an attempt to refine the classification system used in field assessment work. These criteria were based on characteristics of the attachment site that could be identified under field conditions by unaided visual means and by touching the attachment site. Healing of these marks was somewhat variable and was influenced by the size of lamprey, duration of attachment, severity of the wound at lamprey detachment, season and water temperature, and by other less obvious factors. Even under laboratory conditions staging of some wounds was difficult, especially at low water temperatures. If these criteria are to be used effectively and with precision in the field, close examination of individual fish may be required. If the feeding and density of specific year-classes of sea lampreys are to be accurately assessed on an annual basis, close attention to the wound size (as it reflects the size of the lamprey's oral disc) and character of wounds on fish will be required as well as consideration of the season of the year in which they are observed.Key words: sea lamprey, attack marks, lake trout, Great Lakes

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