Pelagic distribution of lake trout (Salvelinus namaycush) in small Canadian Shield lakes with respect to temperature, dissolved oxygen, and light

1998 ◽  
Vol 55 (1) ◽  
pp. 170-179 ◽  
Author(s):  
Todd J Sellers ◽  
Brian R Parker ◽  
David W Schindler ◽  
William M Tonn
Keyword(s):  
Light Intensity ◽  
Dissolved Oxygen ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Canadian Shield ◽  
Small Lakes ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Oxygenated Water ◽  
Shield Lakes

The distribution of lake trout (Salvelinus namaycush) with respect to water temperature, dissolved oxygen, and light intensity was surveyed in three small Canadian Shield lakes at the Experimental Lakes Area, northwestern Ontario. Based on hydroacoustic and gillnet surveys, there was considerable variation among lakes in temperatures occupied by lake trout during the summer. During the day, lake trout were concentrated at 4-8°C in Lake 375, broadly distributed from 6 to 15°C in Lake 442, and concentrated in the epilimnion at 19°C in Lake 468. At night, lake trout in all lakes occupied epilimnetic waters at 19-20°C. Lake trout inhabited highly oxygenated water, with 75-90% of fish at >6 mg dissolved oxygen ·L-1 throughout the spring and summer in all three lakes. Light intensity did not affect lake trout distribution in Lake 468 but may have contributed to lake trout daytime descent into cool waters in Lakes 375 and 442. We suggest that previously assumed niche boundaries of lake trout do not adequately describe critical habitat for the species in small lakes, the same lakes that are likely most sensitive to erosion of such habitat.

Performance of temperature and dissolved oxygen criteria to predict habitat use by lake trout (Salvelinus namaycush)This paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 2011-2023 ◽  
Author(s):  
John M. Plumb ◽  
Paul J. Blanchfield
Keyword(s):  
Habitat Use ◽  
Dissolved Oxygen ◽  
Thermal Stratification ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Experimental Lakes Area ◽  
Lake Volume ◽  
Northwestern Ontario ◽  
Environmental Extremes

We compared theoretical habitat volumes, determined from traditional combinations of temperature and dissolved oxygen concentration (DO) boundaries, with in situ habitat use by acoustically tagged lake trout ( Salvelinus namaycush ). The widely used criteria of 8–12 °C underestimated lake trout habitat use by 68%–80%. Instead, combined temperature (<12 or 15 °C) and DO (>4 or 6 mg·L–1) criteria most closely matched lake trout habitat use, had a similar seasonal trend as the tagged fish, suggested modest reductions (5% of total lake volume) in habitat during a warmer year, and performed best when the constraints of temperature and DO were most limiting. All data were collected in a small boreal shield lake (27 ha, zmax = 21 m) at the Experimental Lakes Area in northwestern Ontario, Canada, during two contrasting periods of thermal stratification (2003: warmer and longer; 2004: cooler and shorter), providing an assessment of observed and theoretical habitat volumes over current environmental extremes.

Land water linkages: influences of riparian deforestation on lake thermocline depth and possible consequences for cold stenotherms

1997 ◽  
Vol 54 (6) ◽  
pp. 1299-1305 ◽  
Author(s):  
Robert France
Keyword(s):  
Thermal Stratification ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Thermocline Depth ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Riparian Trees ◽  
Tree Removal ◽  
Riparian Tree ◽  
Land Water

The purpose of the present study was to determine if riparian deforestation would expose lake surfaces to stronger winds and therefore bring about deepening of thermoclines and resulting habitat losses for cold stenotherms such as lake trout (Salvelinus namaycush). Removal of protective riparian trees through wind blowdown and two wildfires was found to triple the overwater windspeeds and produce thermocline deepening in two lakes at the Experimental Lakes Area. A survey of thermal stratification patterns in 63 northwestern Ontario lakes showed that lakes around which riparian trees had been removed a decade before through either clearcutting or by a wildfire were found to have thermocline depths over 2 m deeper per unit fetch length compared with lakes surrounded by mature forests. Riparian tree removal will therefore exacerbate hypolimnion habitat losses for cold stenotherms that have already been documented to be occurring as a result of lake acidification, eutrophication, and climate warming.

Survival and Development of Lake Trout (Salvelinus namaycush) embryos in an Acidified Lake in Northwestern Ontario

1990 ◽  
Vol 47 (2) ◽  
pp. 236-243 ◽  
Author(s):  
L. C. Mohr ◽  
K. H. Mills ◽  
J. F. Klaverkamp
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Experimental Lakes Area ◽  
Embryo Survival ◽  
Embryo Mortality ◽  
Recruitment Failure ◽  
Northwestern Ontario ◽  
Survival And Development ◽  
Population Recruitment ◽  
Experimental Acidification

Survival and development of lake trout (Salvelinus namaycush) embryos from L223 in the Experimental Lakes Area, northwestern Ontario, were evaluated from 1979 (pH 5.6) to 1982 (pH 5.1). Survival of L223 embryos was not significantly correlated to lake pH during experimental acidification. Also, embryo mortality in L223 was not significantly different from that of lake trout embryos in two reference lakes, L224 and L468. Survival of L223 embryos was not improved when they were incubated in nonacidified lakes. Embryo mortality was highest in all lakes (33–81%) within 15 d of fertilization. Mortality was negligible from Day 15 until the termination of the seasonal observations (Day 120 or 150). High variability in embryo survival existed between individual females within a single lake. The mean size of eggs from L223 lake trout decreased significantly from 1979 to 1982. Recruitment failures occurred in L223 from 1980 to 1982. We hypothesize that lake trout recruitment failure in L223 occurred between the posthatching period (spring) and actual recruitment into the population as young-of-the-year (fall) and that embryo mortality in this lake was not critical to population recruitment.

Responses of Fish Populations in Lake 223 to 8 Years of Experimental Acidification

1987 ◽  
Vol 44 (S1) ◽  
pp. s114-s125 ◽  
Author(s):  
K. H. Mills ◽  
S. M. Chalanchuk ◽  
L. C. Mohr ◽  
I. J. Davies
Keyword(s):  
Fathead Minnow ◽  
Lake Trout ◽  
Pimephales Promelas ◽  
Salvelinus Namaycush ◽  
Early Years ◽  
White Sucker ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Slimy Sculpin ◽  
Experimental Acidification

Lake 223 in the Experimental Lakes Area, northwestern Ontario, was experimentally acidified with sulfuric acid from 1976 (initial average pH 6.49) to 1981 (average pH 5.02), and then maintained at pH 5.02 to 5.13 from 1981 to 1983. Lake trout (Salvelinus namaycush), white sucker (Catostomus commersoni), fathead minnow (Pimephales promelas), and slimy sculpin (Cottus cognatus) were abundant at the onset of acidification. A decline in the abundance of fathead minnow began in 1979 (pH 5.64), and was followed first by a rapid increase in number of pearl dace (Semotilus margarita) in 1980 (pH 5.59) and then a rapid decrease in 1982 (pH 5.09). The abundance of slimy sculpin decreased rapidly in 1979. Abundances of lake trout and white sucker increased during the early years of acidification, but declined following consecutive recruitment failures starting in 1980 for trout and in 1981 for white suckers. By 1982 recruitment had ceased for all Lake 223 fishes. Survival of lake trout [Formula: see text] age 1 decreased in 1982 and 1983, but no other changes in survival of fish [Formula: see text] age 1 were detected for lake trout or white sucker. By spring 1983 many lake trout were emaciated due to losses of the lake trout food organisms. No changes in growth of lake trout and white suckers occurred during the initial years of acidification, but growth of lake trout slowed in 1982 and growth of white sucker increased in 1979.

Geochemical Pathways and Biological Uptake of Radium in Small Canadian Shield Lakes

1984 ◽  
Vol 41 (3) ◽  
pp. 459-468 ◽  
Author(s):  
R. H. Hesslein ◽  
E. Slavicek
Keyword(s):  
Lake Trout ◽  
Pimephales Promelas ◽  
Canadian Shield ◽  
Coregonus Clupeaformis ◽  
Experimental Lakes Area ◽  
Biological Uptake ◽  
Single Addition ◽  
Shield Lakes ◽  
Large Adult

The sediment–water interactions and biological uptake of 226Ra are described for four small Canadian Shield lakes at the Experimental Lakes Area, Kenora, Ont. A single addition of 226Ra was made to each lake between 1970 and 1976. Approximately 90% of the added 226Ra initially sorbed to the sediments. Outflow from the lakes showed losses of only 5–11% 226Ra per year. Models are proposed for adsorption and outflow of 226Ra from lakes. Biological uptake and long-term 226Ra concentrations were measured in three species of macrophytes, crayfish, and five species of fish. Bioaccumulation ranged from 1100 to 5000 in macrophytes, 750 in crayfish, from 30 to 80 in large adult lake trout (Salvelinus namaycush), white sucker (Catostomus commersoni), and lake whitefish (Coregonus clupeaformis), and from 230 to 1200 in fathead minnows (Pimephales promelas), pearl dace (Semotilus margarita), and northern redbelly dace (Chrosomus eos). The concept of Ra/Ca ratio in organisms versus water and food is used to explain the differences in bioaccumulation. 226Ra is discriminated against versus calcium by fish but favored by macrophytes and crayfish.

Aphanizomenon schindleri sp.nov.: a new nostocacean cyanoprokaryote from the Experimental Lakes Area, northwestern Ontario

1994 ◽  
Vol 51 (10) ◽  
pp. 2267-2273 ◽  
Author(s):  
Hedy J. Kling ◽  
David L. Findlay ◽  
Jiri Komárek
Keyword(s):  
Cell Shape ◽  
Canadian Shield ◽  
Experimental Lakes Area ◽  
N Limitation ◽  
Northwestern Ontario ◽  
Cell Dimensions ◽  
N Loading ◽  
Shield Lakes

Aphanizomenon schindleri sp.nov., a new nostocacean, bluegreen, cyanoprokaryote (cyanobacterium), is described from artificially eutrophied Canadian Shield lakes in the Experimental Lakes Area, northwestern Ontario. It is unique to low conductivity Canadian Shield waters to which nutrients have been added, and it became the dominant bloom species after years of phosphorus (P) and nitrogen (N) loading followed by N limitation (N:P ≤ 5:1 by mass) (Findlay et al. 1994. Can. J. Fish. Aquat. Sci. 51: 2254–2266). The new Aphanizomenon species appears to be most closely related to A. gracile but also resembles species of Anabaena with straight filaments. It differs from other species of Aphanizomenon in cell dimensions, length and width of akinetes and heterocytes, and in akinete and end cell shape.

Decline of Mysis relicta During the Acidification of Lake 223

1983 ◽  
Vol 40 (11) ◽  
pp. 1905-1911 ◽  
Author(s):  
R. W. Nero ◽  
D. W. Schindler
Keyword(s):  
Confidence Limits ◽  
Experimental Lakes Area ◽  
Mysis Relicta ◽  
Ph Values ◽  
Northwestern Ontario ◽  
Population Comparisons ◽  
Acidification Of Lake ◽  
Ph Range ◽  
Shield Lakes ◽  
Direct Toxicity

The population size of Mysis relicta in Lake 223 of the Experimental Lakes Area, northwestern Ontario, decreased from 6 700 000 ± 1 330 000 (± 95% confidence limits) during August of 1978, to 270 000 ± 75 000 during August of 1979, a 96% decrease. Because Mysis, a cold stenotherm, is restricted to the metalimnion and hypolimnion of lakes during summer, the pH range encountered by the population was 5.51 to 6.32 in 1978 and 5.23 to 6.10 in 1979, even though mean pH values in epilimnion waters for the 2 yr were 5.84 and 5.60. A decrease in pH of its habitat from 6.2 to 5.6 during fall overturn in 1979 caused the elimination of the remaining 4% of the population. Comparisons with four control lakes suggested that the decline and disappearance were not normal occurrences in unstressed lakes. Concentrations of Zn, Al, Mn, Fe, Cd, Cu, Ni, and Hg in Lake 223 water were low, and concentrations in Mysis were less than or equal to those in animals from five control lakes, suggesting that the decline in this species was not due to the toxic effects of metals. All size classes were affected, so that direct toxicity of hydrogen ion may be responsible for this abrupt population collapse. These results suggest that Mysis may be a useful early indicator of acidification damage to Precambrian Shield lakes.

Effect of light intensity and substrate type on siscowet lake trout (Salvelinus namaycush siscowet) predation on deepwater sculpin (Myoxocephalus thompsonii)

Hydrobiologia ◽  
2019 ◽  
Vol 840 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Trevor D. Keyler ◽  
Thomas R. Hrabik ◽  
Allen F. Mensinger ◽  
Loranzie S. Rogers ◽  
Owen T. Gorman
Keyword(s):  
Light Intensity ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Substrate Type ◽  
Effect Of Light

Effects of Lake Size on Phytoplankton Nutrient Status

1994 ◽  
Vol 51 (12) ◽  
pp. 2769-2783 ◽  
Author(s):  
S. J. Guildford ◽  
L. L. Hendzel ◽  
H. J. Kling ◽  
E. J. Fee ◽  
G. G. C. Robinson ◽  
...  
Keyword(s):  
Nutrient Status ◽  
Canadian Shield ◽  
Small Lakes ◽  
Large Lakes ◽  
P Deficiency ◽  
Water Renewal ◽  
Mixed Layers ◽  
Shield Lakes ◽  
Lake Size ◽  
Total P

Phytoplankton nutrient status measurements (C/P, C/N, C/chlorophyll, N/P, alkaline phosphatase activity, and N debt) were measured for 6 yr in seven remote Canadian Shield lakes. Lakes Nipigon and Superior were also studied for 2 yr. These lakes varied in surface area from 29 to 8.223 × 10 ha, they all stratified fully during the summer and had water renewal times > 5 yr. All lakes were severely P deficient; however, the large lakes (> 2000 ha) were consistently less P deficient than small lakes. A growth-rate indicator (photosynthesis normalized to particulate C) agreed with nutrient status indicators, in that small lakes had lower rates than large lakes. Total P was a good predictor of chlorophyll, but factors related to lake size (temperature and mixed depth) were equally good or better predictors of nutrient status. Decreasing mean water column light intensity could not explain the lower P deficiency of large lakes. The deeper, more energetic mixed layers in large lakes apparently cause P to be recycled more efficiently. Extrapolation of observations or experimental results from small to large lakes requires recognition that phytoplankton in large lakes are less nutrient deficient and may have higher growth rates.

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