Hypersaline Gradients in Two Canadian High Arctic Lakes

1986 ◽  
Vol 43 (9) ◽  
pp. 1795-1803 ◽  
Author(s):  
Kenton M. Stewart ◽  
Robert F. Platford
Keyword(s):  
High Arctic ◽  
Arctic Lakes ◽  
Canadian High Arctic ◽  
Salt Fingers ◽  
The Stability ◽  
Freeze Out

The meromictic Sophia and Garrow lakes are probably saline relicts of cutoff fjords on the uplifted Cornwallis and Little Cornwallis islands in the High Arctic of the Canadian Archipelago. Sophia and Garrow have brackish (S = 2–4) upper and hypersaline (S = 55–90) lower waters with ion ratios (especially the lower waters) similar to that of the sea. Substantial oxygen extends well below the chemocline in Sophia. The stability of these lakes is among the highest known. Because of their size, depth, and unusually warm lower waters, it seems likely that an unfrozen "thermal chimney" extends beneath the lakes through the surrounding permafrost. We feel that the hypersaline gradients evolved primarily by descent of "salt fingers" during freeze out from above, and not by solute rejection from the ground during uplift and permafrost growth, or through taliks connected to the sea, as proposed by Page et al. (1984. Limnol. Oceanogr. 29: 564–573).

Slow growth and decomposition of mosses in Arctic lakes

1999 ◽  
Vol 56 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Kaj Sand-Jensen ◽  
Tenna Riis ◽  
Stiig Markager ◽  
Warwick F Vincent
Keyword(s):  
High Arctic ◽  
Arctic Lakes ◽  
Canadian High Arctic ◽  
Cold Temperatures ◽  
Direct Measurements ◽  
Aquatic Mosses ◽  
Lake Bottom ◽  
Different Depths ◽  
North Lake ◽  
Methodological Difficulties

Aquatic mosses are often the exclusive form of macrophytic vegetation in Arctic lakes. Despite the cold nutrient-poor water and the short ice-free summer, the mosses form dense stands on the lake bottom down to great depths. The environmental conditions suggest that moss growth and decomposition are extremely slow, but logistical and methodological difficulties have so far precluded direct measurements of the processes. Here, we use temporal changes in the size and density of leaves along the axis of moss shoots collected from different depths in Char Lake and North Lake in the Canadian High Arctic to reconstruct the annual growth and decomposition of the mosses during the past 10-17 years. Our results show low but remarkably constant annual elongation rates (about 10 mm·shoot-1) in the long-lived shoots that carry green leaves for several years and decompose slowly. Cold temperatures and low nutrient supply in combination with the short Arctic growing season can account for the low growth rate, the low decomposition rates, and the unprecedented longevity of these moss communities relative to other submerged macrophytes.

Structural variation in the songs of Atlantic walruses breeding in the Canadian High Arctic

2003 ◽  
Vol 29 (2) ◽  
pp. 297-318 ◽  
Author(s):  
Becky Sjare ◽  
Ian Stirling ◽  
Cheryl Spencer
Keyword(s):  
Structural Variation ◽  
High Arctic ◽  
Canadian High Arctic

In situ optical and microphysical properties of tropospheric aerosols in the Canadian High Arctic from 2016 to 2019

2021 ◽  
Vol 250 ◽  
pp. 118254
Author(s):  
Andy Vicente-Luis ◽  
Samantha Tremblay ◽  
Joelle Dionne ◽  
Rachel Y.-W. Chang ◽  
Pierre F. Fogal ◽  
...  
Keyword(s):  
High Arctic ◽  
Canadian High Arctic ◽  
Microphysical Properties ◽  
Tropospheric Aerosols

scholarly journals Climate Change Drives Widespread and Rapid Thermokarst Development in Very Cold Permafrost in the Canadian High Arctic

2019 ◽  
Vol 46 (12) ◽  
pp. 6681-6689 ◽  
Author(s):  
Louise M. Farquharson ◽  
Vladimir E. Romanovsky ◽  
William L. Cable ◽  
Donald A. Walker ◽  
Steven V. Kokelj ◽  
...  
Keyword(s):  
Climate Change ◽  
High Arctic ◽  
Canadian High Arctic

scholarly journals Assessing the utility of sulfur isotope values for understanding mercury concentrations in water and biota from high Arctic lakes

2019 ◽  
Vol 5 (2) ◽  
pp. 90-106 ◽  
Author(s):  
Gretchen L. Lescord ◽  
Meredith G. Clayden ◽  
Karen A. Kidd ◽  
Jane L. Kirk ◽  
Xiaowa Wang ◽  
...  
Keyword(s):  
Food Webs ◽  
Total Mercury ◽  
Nitrogen Isotopes ◽  
Sulfur Isotopes ◽  
High Arctic ◽  
Arctic Lakes ◽  
Carbon And Nitrogen ◽  
Resolute Bay ◽  
Aquatic Food ◽  
Globally Stable

Methylmercury (MeHg) biomagnifies through aquatic food webs resulting in elevated concentrations in fish globally. Stable carbon and nitrogen isotopes are frequently used to determine dietary sources of MeHg and to model its biomagnification. However, given the strong links between MeHg and sulfur cycling, we investigated whether sulfur isotopes (δ34S) would improve our understanding of MeHg concentrations ([MeHg]) in Arctic lacustrine food webs. Delta34S values and total mercury (THg) or MeHg were measured in water, sediments, and biota from six lakes near Resolute Bay, NU, Canada. In two lakes impacted by historical eutrophication, aqueous sulfate δ34S was ∼8‰ more positive than sedimentary δ34S, suggestive of bacterial sulfate reduction in the sediment. In addition, aqueous δ34S showed a significant positive relationship with aqueous [MeHg] across lakes. Within taxa across lakes, [THg] in Arctic char muscle and [MeHg] in their main prey, chironomids, were positively related to their δ34S values across lakes, but inconsistent relationships were found across entire food webs among lakes. Across lakes, nitrogen isotopes were better predictors of biotic [THg] and [MeHg] than δ34S within this dataset. Our results suggest some linkages between Hg and S biogeochemistry in high Arctic lakes, which is an important consideration given anticipated climate-mediated changes in nutrient cycling.

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