scholarly journals Patterns in the limnology of lakes and ponds across multiple local and regional environmental gradients in the eastern Canadian Arctic

Inland Waters ◽  
2012 ◽  
Vol 2 (2) ◽  
pp. 59-76 ◽  
Author(s):  
Andrew Medeiros
Keyword(s):  
Environmental Gradients ◽  
Canadian Arctic ◽  
Eastern Canadian Arctic

The distribution of the Chironomidae (Insecta: Diptera) along multiple environmental gradients in lakes and ponds of the eastern Canadian Arctic

2011 ◽  
Vol 68 (9) ◽  
pp. 1511-1527 ◽  
Author(s):  
Andrew S. Medeiros ◽  
Roberto Quinlan
Keyword(s):  
Trophic Status ◽  
Environmental Gradients ◽  
Canadian Arctic ◽  
Primary Response ◽  
Environmental Data ◽  
Arctic Lakes ◽  
Tree Line ◽  
Aquatic Communities ◽  
Arctic Water ◽  
Eastern Canadian Arctic

An examination of the Chironomidae, the dominant aquatic invertebrate taxa found in Arctic lakes and ponds, was conducted to determine the environmental gradients that may limit their geographical distribution in the eastern Canadian Arctic. Subfossil chironomid head capsules, comprising 86 taxa, were sampled from surficial sediments of 63 lakes that spanned from tree line (northern Manitoba) across multiple regions within the eastern Canadian Arctic. Water chemistry and environmental data were then compared with chironomid assemblages using multivariate analysis. The distribution of chironomids was found to primarily follow a temperature gradient, but additional significant relationships were also found along a nutrient–productivity gradient. Several species of the Tribe Chironomini, which generally represent warm-water adapted taxa, were also found far beyond tree line in the southern Kivalliq region of Nunavut, indicating a more northerly range than previously known. While temperature and trophic status were found to strongly influence the distribution of some taxa, partially constrained gradient analysis indicates that specific chironomid taxa could be used to indicate a primary response to climate regardless of trophic status. This may allow for more holistic inferences of how aquatic communities may respond to climate change as the range of temperature dependant species expand into Arctic systems.

Conodont paleontology and biostratigraphy of Ordovician carbonates and petroliferous carbonates on Southampton, Baffin, and Akpatok islands in the eastern Canadian Arctic

1989 ◽  
Vol 26 (10) ◽  
pp. 1880-1903 ◽  
Author(s):  
Alexander D. McCracken ◽  
Godfrey S. Nowlan
Keyword(s):  
Canadian Arctic ◽  
Bedding Plane ◽  
Baffin Island ◽  
Jordan River ◽  
Oil Shales ◽  
Age Range ◽  
Eastern Canadian Arctic

Carbonate and petroliferous carbonate units ("oil shales") on Southampton, Baffin, and Akpatok islands have yielded a total of 2277 conodonts, the more biostratigraphically useful of which indicate not all units are correlative. The Boas River "shale", the lower of the two petroliferous units on Southampton Island, overlies the Bad Cache Rapids Group and contains a diverse fauna, including elements of Amorphognathus ordovicicus Branson and Mehl. Previous reports have indicated the presence of Culumbodina penna Sweet, a species whose range only barely overlaps that of A. ordovicicus in the middle Maysvillian. Carbonate beds and bedding-plane surfaces of the higher Red Head Rapids Formation at Sixteen Mile Brook yielded A. ordovicicus faunas containing Aphelognathus cf. A. divergens Sweet. These beds are likely Richmondian, since A. divergens is known elsewhere only from Richmondian strata. A metasicula of "Glyptograptus" hudsoni Jackson, several natural conodont assemblages, and fused enigmatic coniform elements were also found at Sixteen Mile Brook.The petroliferous unit in unnamed strata at Amadjuak Lake on Baffin Island contains Belodina area Sweet, which is indicative of a late Edenian to early Maysvillian age. Conodonts from the petroliferous strata at Jordan River on Baffin Island suggest a Trentonian to early Maysvillian age. The conodonts recovered from unnamed strata on Akpatok Island are not very diagnostic but indicate an age range from Shermanian to Gamachian.

An early nineteenth century meteorological register from the eastern Canadian Arctic

Polar Record ◽  
1995 ◽  
Vol 31 (178) ◽  
pp. 335-342 ◽  
Author(s):  
Paul A. Kay
Keyword(s):  
Nineteenth Century ◽  
Canadian Arctic ◽  
The Arctic ◽  
Research Centre ◽  
Historical Reconstruction ◽  
Early Nineteenth Century ◽  
Northwest Passage ◽  
Time Periods ◽  
Modern Experience ◽  
Eastern Canadian Arctic

AbstractSignificant warming in the Arctic is anticipated for doubled-CO2 scenarios, but temperatures in the eastern Canadian Arctic have not yet exhibited that trend in the last few decades. The spatial juxtaposition of the winter station in 1822–1823 of William Edward Parry's Northwest Passage expedition with the modern Igloolik Research Centre of the Science Institute of the Northwest Territories affords an opportunity for historical reconstruction and comparison. Parry's data are internally consistent. The association of colder temperatures with westerly and northerly winds, and wanner temperatures with easterly and southerly winds, is statistically significant. Temperatures are not exactly comparable between the two time periods because of differences in instrumentation, exposure, and frequency of readings. Nevertheless, in 1822–1823, November and December appear to have been cold and January to March mild compared to modern experience. Anomalously, winds were more frequently northerly (and less frequently westerly) in the latter months than in recent observations. Parry recorded two warm episodes in mid-winter, but, overall, it appears that the winter of 1822–1823 was not outside the range of modern experience.

scholarly journals Rare earth elements in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic

2017 ◽  
Vol 19 (10) ◽  
pp. 1336-1345 ◽  
Author(s):  
Gwyneth Anne MacMillan ◽  
John Chételat ◽  
Joel P. Heath ◽  
Raymond Mickpegak ◽  
Marc Amyot
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Canadian Arctic ◽  
Terrestrial Ecosystems ◽  
Eastern Canadian Arctic

Rare earth elements show consistent bioaccumulation patterns yet limited biomagnification in remote northern ecosystems.

Mercury concentrations in multiple tissues of Arctic Iceland Gulls (Larus glaucoides) wintering in Newfoundland

2015 ◽  
Vol 1 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Alexander L. Bond ◽  
Gregory J. Robertson
Keyword(s):  
Blood Cell ◽  
Blood Plasma ◽  
Newfoundland And Labrador ◽  
Blood Cells ◽  
Feeding Habits ◽  
Canadian Arctic ◽  
Total Blood ◽  
Human Habitation ◽  
Mercury In Blood ◽  
Eastern Canadian Arctic

Anthropogenic mercury (Hg) emissions are increasing and are potentially of concern for Arctic-nesting seabirds, particularly those that spend part of their year near dense human habitation. Iceland Gulls (Larus glaucoides B. Meyer, 1822) breed in the eastern Canadian Arctic and spend the majority of winter in towns and cities in eastern Newfoundland. We measured Hg in breast feathers, blood plasma, and red blood cells of Iceland Gulls wintering in and around St. John's, Newfoundland and Labrador, from 2011 to 2014. Mercury in blood plasma comprised <10% of the total blood Hg. We found no difference in red blood cell Hg between first-winter and adult birds, which likely reflects their similar feeding habits. Feather Hg in adults was significantly greater than that in first-winter birds because adults had accumulated a greater body Hg burden to excrete (up to a year, compared with a few months' accumulation in first-winter birds). Overall, concentrations were among the lowest found for Larus spp. and Arctic gulls, suggesting that Hg does not pose a risk to Iceland Gulls at the present.

scholarly journals Thermokarst lake development in syngenetic ice-wedge polygon terrain in the Eastern Canadian Arctic (Bylot Island, Nunavut)

2019 ◽  
Author(s):  
Frédéric Bouchard ◽  
Daniel Fortier ◽  
Michel Paquette ◽  
Vincent Boucher ◽  
Reinhard Pienitz ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Canadian Arctic ◽  
Climatic Conditions ◽  
Gradual Transition ◽  
Freshwater Environment ◽  
Cooling Period ◽  
Lake Development ◽  
Thermokarst Lake ◽  
Ice Wedge ◽  
Eastern Canadian Arctic

Abstract. Thermokarst lakes are widespread and diverse across permafrost regions and they are considered significant contributors to global greenhouse gas emissions. Paleoenvironmental reconstructions documenting the inception and development of these ecologically important water bodies are generally limited to Pleistocene-age permafrost deposits (Yedoma) of Siberia, Alaska, and the western Canadian Arctic. Here we present the gradual transition from syngenetic ice-wedge polygon terrains to a thermokarst lake in the Eastern Canadian Arctic. We combine geomorphological surveys with paleolimnological reconstructions from sediment cores in an effort to characterize local landscape evolution from terrestrial to freshwater environment. Located on an ice-rich and organic-rich polygonal terrace, the studied lake is now evolving through active thermokarst, as revealed by subsiding and eroding shores, and was likely created by water pooling within a pre-existing topographic depression. Organic sedimentation in the valley started during the mid-Holocene, as documented by the oldest organic debris found at the base of one sediment core and dated at 4.8 kyr BP. Local sedimentation dynamics were initially controlled by fluctuations in wind activity, local moisture and vegetation growth/accumulation, as shown by alternating loess (silt) and peat layers. Fossil diatom assemblages were likewise influenced by local hydro-climatic conditions and reflect a broad range of substrates available in the past (both terrestrial and aquatic). Such conditions likely prevailed until ~ 2000 BP, when peat accumulation stopped as water ponded the surface of degrading ice-wedge polygons, and the basin progressively developed into a thermokarst lake. Interestingly, this happened in the middle of the Neoglacial cooling period, likely under wetter-than-average conditions. Thereafter, the lake continued to develop as evidenced by the dominance of aquatic (both benthic and planktonic) diatom taxa in organic-rich lacustrine muds. Based on these interpretations, we present a four-stage conceptual model of thermokarst lake development during the late Holocene, including some potential future trajectories. Such a model could be applied to other formerly glaciated syngenetic permafrost landscapes.

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