Projected impacts of climate warming on production of lake trout (Salvelinus namaycush) in southern Yukon lakes

2006 ◽  
Vol 63 (4) ◽  
pp. 788-797 ◽  
Author(s):  
Jody L Mackenzie-Grieve ◽  
John R Post

We used existing models to predict changes in lake surface temperature and thermocline depth, in combination with a newly developed model to describe lake thermal profiles, to determine how thermal properties of a series of lakes located predominantly in the southern Yukon could change under three realistic climate-warming scenarios. We then used existing models to determine how relative changes in potential harvest of lake trout (Salvelinus namaycush) in southern Yukon lakes could change as availability of optimal thermal habitat was altered under the three warming scenarios. With warming, an overall decrease in availability of optimal thermal habitat and in lake trout potential harvest is predicted in southern Yukon lakes, although considerable lake-specific variation in direction and magnitude of change exists. For southern Yukon lakes overall, 2, 4, and 6 °C increases in mean annual air temperature lead to 12%, 35%, and 40% decreases in thermal habitat volume, respectively, and 8%, 19%, and 23% reductions in potential harvest, respectively.


1997 ◽  
Vol 54 (6) ◽  
pp. 1299-1305 ◽  
Author(s):  
Robert France

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.



2003 ◽  
Vol 29 ◽  
pp. 347-361 ◽  
Author(s):  
Roger A. Bergstedt ◽  
Ray L. Argyle ◽  
James G. Seelye ◽  
Kim T. Scribner ◽  
Gary L. Curtis


2018 ◽  
Vol 10 (7) ◽  
pp. 1152 ◽  
Author(s):  
Jie Chen ◽  
Frank Günther ◽  
Guido Grosse ◽  
Lin Liu ◽  
Hui Lin

Yedoma—extremely ice-rich permafrost with massive ice wedges formed during the Late Pleistocene—is vulnerable to thawing and degradation under climate warming. Thawing of ice-rich Yedoma results in lowering of surface elevations. Quantitative knowledge about surface elevation changes helps us to understand the freeze-thaw processes of the active layer and the potential degradation of Yedoma deposits. In this study, we use C-band Sentinel-1 InSAR measurements to map the elevation changes over ice-rich Yedoma uplands on Sobo-Sise Island, Lena Delta with frequent revisit observations (as short as six or 12 days). We observe significant seasonal thaw subsidence during summer months and heterogeneous inter-annual elevation changes from 2016–17. We also observe interesting patterns of stronger seasonal thaw subsidence on elevated flat Yedoma uplands by comparing to the surrounding Yedoma slopes. Inter-annual analyses from 2016–17 suggest that our observed positive surface elevation changes are likely caused by the delayed progression of the thaw season in 2017, associated with mean annual air temperature fluctuations.



2000 ◽  
Vol 57 (S2) ◽  
pp. 82-91 ◽  
Author(s):  
Robert J Steedman ◽  
Robert S Kushneriuk

Clearcut logging around three 30- to 40-ha dimictic northwestern Ontario lakes was associated with increases of 5% or less in midlake wind speed and no measurable changes in spring and fall circulation efficiency or duration of stratification. Water clarity, indexed as the depth at which photosynthetically active radiation was 1% of surface intensity, declined by 25% after 3 years. Late-summer thermoclines were about 1 m shallower in two lakes after logging, but it was not possible to exclude weather as a factor. None of the lakes showed significant declines in lake trout (Salvelinus namaycush) habitat volume. A forested shoreline buffer strip around one of the lakes prevented increases in midlake wind speed but did not prevent declines in water clarity and thermocline depth.



Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 634
Author(s):  
Jiahe Lang ◽  
Yaoming Ma ◽  
Zhaoguo Li ◽  
Dongsheng Su

Increasing air temperature is a significant feature of climate warming, and is cause for some concern, particularly on the Tibetan Plateau (TP). A lack of observations means that the impact of rising air temperatures on TP lakes has received little attention. Lake surfaces play a unique role in determining local and regional climate. This study analyzed the effect of increasing air temperature on lake surface temperature (LST), latent heat flux (LE), sensible heat flux (H), and ice phenology at Lake Nam Co and Lake Ngoring, which have mean depths of approximately 40 m and 25 m, respectively, and are in the central and eastern TP, respectively. The variables were simulated using an adjusted Fresh-water Lake (FLake) model (FLake_α_ice = 0.15). The simulated results were evaluated against in situ observations of LST, LE and H, and against LST data derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) for 2015 to 2016. The simulations show that when the air temperature increases, LST increases, and the rate of increase is greater in winter than in summer; annual LE increases; H and ice thickness decrease; ice freeze-up date is delayed; and the break-up date advances. The changes in the variables in response to the temperature increases are similar at the two lakes from August to December, but are significantly different from December to July.



2010 ◽  
Vol 67 (12) ◽  
pp. 2002-2013 ◽  
Author(s):  
Peter C. Jacobson ◽  
Heinz G. Stefan ◽  
Donald L. Pereira

An empirical model was developed that describes the influence of lake productivity, climate, and morphometry on coldwater fish oxythermal habitat. An oxythermal habitat variable called temperature at 3 mg·L–1 of dissolved oxygen (TDO3) was developed by interpolating the water temperature at a benchmark oxygen concentration (3 mg·L–1) from a temperature–oxygen profile. Coldwater habitat was most available in the least productive lakes (total P < 25 µg·L–1) with the greatest relative depths (geometry ratios < 2 m–0.5) and where mean July air temperatures were less than 17 °C. Species response curves were developed from values of TDO3 measured during the greatest period of oxythermal stress in late summer (maxTDO3). Lake trout was present in lakes with the lowest values of maxTDO3, while cisco was present in lakes with the highest and broadest range of maxTDO3. Projections for a scenario where climate warming (+4 °C in mean July air temperature) was accompanied by eutrophication (doubling of total P) indicated that coldwater fish oxythermal habitat would be devastated in a subset of lakes typical for Minnesota. Protecting deep, unproductive lakes from eutrophication will be a necessary management strategy to ensure that coldwater fish persist in at least some Minnesota lakes after climate warming.



Author(s):  
Alexander Gatch ◽  
Dimitry Gorsky ◽  
Zy Biesinger ◽  
Eric Bruestle ◽  
Kelley Lee ◽  
...  


1997 ◽  
Vol 54 (5) ◽  
pp. 1031-1038
Author(s):  
C A Stow ◽  
L J Jackson ◽  
J F Amrhein

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.



1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.

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



1989 ◽  
Vol 46 (3) ◽  
pp. 384-388 ◽  
Author(s):  
F. W. H. Beamish ◽  
J. C. Howlett ◽  
T. E. Medland

Juvenile lake trout, Salvelinus namaycush, of similar size were fed one of three isocaloric diets, each differing in protein and lipid content. Oxygen consumption and swimming performance were measured in a recirculating water flume at intervals throughout the 70-d feeding trials (10 °C). Swimming speed was increased by stepwise velocity increments (5 cm∙s−1) and oxygen consumption was measured at each velocity between 20 and 45 cm∙s−1. Oxygen consumption for a given speed did not differ significantly throughout the feeding trial nor among the diets implying a similarity in the quality and quantity of substrate catabolized for energy. Basal metabolism (0 cm∙s−1) was also independent of diet and feeding interval. Critical swimming speed increased with dietary and carcass protein content to suggest a direct association with muscle mass and number of myofilaments.



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