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.

scholarly journals Kelp in the Eastern Canadian Arctic: Current and Future Predictions of Habitat Suitability and Cover

2021 ◽  
Vol 18 ◽  
Author(s):  
Jesica Goldsmit ◽  
Robert W. Schlegel ◽  
Karen Filbee-Dexter ◽  
Kathleen A. MacGregor ◽  
Ladd E. Johnson ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Canadian Arctic ◽  
Environmental Data ◽  
Saccharina Latissima ◽  
Suitable Habitat ◽  
Percent Cover ◽  
Arctic Ecosystems ◽  
Modeling Approaches ◽  
Eastern Canadian Arctic ◽  
Occurrence Records

Climate change is transforming marine ecosystems through the expansion and contraction of species’ ranges. Sea ice loss and warming temperatures are expected to expand habitat availability for macroalgae along long stretches of Arctic coastlines. To better understand the current distribution of kelp forests in the Eastern Canadian Arctic, kelps were sampled along the coasts for species identifications and percent cover. The sampling effort was supplemented with occurrence records from global biodiversity databases, searches in the literature, and museum records. Environmental information and occurrence records were used to develop ensemble models for predicting habitat suitability and a Random Forest model to predict kelp cover for the dominant kelp species in the region – Agarum clathratum, Alaria esculenta, and Laminariaceae species (Laminaria solidungula and Saccharina latissima). Ice thickness, sea temperature and salinity explained the highest percentage of kelp distribution. Both modeling approaches showed that the current extent of arctic kelps is potentially much greater than the available records suggest. These modeling approaches were projected into the future using predicted environmental data for 2050 and 2100 based on the most extreme emission scenario (RCP 8.5). The models agreed that predicted distribution of kelp in the Eastern Canadian Arctic is likely to expand to more northern locations under future emissions scenarios, with the exception of the endemic arctic kelp L. solidungula, which is more likely to lose a significant proportion of suitable habitat. However, there were differences among species regarding predicted cover for both current and future projections. Notwithstanding model-specific variation, it is evident that kelps are widespread throughout the area and likely contribute significantly to the functioning of current Arctic ecosystems. Our results emphasize the importance of kelp in Arctic ecosystems and the underestimation of their potential distribution there.

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.

Phytoplankton of cold-water lake ecosystems under the influence of natural and anthropogenic factors

2021 ◽  
pp. 42-49
Author(s):  
Andrey N. Sharov
Keyword(s):  
Heavy Metals ◽  
Cold Water ◽  
Arctic Lakes ◽  
Water Bodies ◽  
The Arctic ◽  
Anthropogenic Factors ◽  
Large Lakes ◽  
Arctic Water ◽  
The North ◽  
Natural And Anthropogenic Factors

Based on the study of the spatio-temporal aspects of the development of phytoplankton in the lakes of the North and North-West of the European territory of Russia (large lakes – Imandra, Onega and Chudsko-Pskovskoye and small lakes of the Arctic and Subarctic), the features of its structure and dynamics under the influence of natural and anthropogenic factors (eutrophication, heavy metal pollution, acidification, thermification). The species composition and quantitative characteristics of phytoplankton of large lakes of the North of Russia, small arctic lakes and lakes of subarctic regions are studied. It has been shown that diatoms predominate in arctic water bodies according to species diversity, and green and diatoms predominate in boreal ones. By biomass, diatoms dominate mainly in all cold-water lakes, with the exception of small arctic lakes, where golden algae lead. The features of the reorganization of phytoplankton in response to the action of anthropogenic factors are revealed. It is proved that in the northern water bodies the complex action of heavy metals and nutrients does not lead to inhibition of phytoplankton, and the effect of acidification in combination with heavy metals enhances the toxic effect of the latter. A feature of the response to acidification is an increase in the variability of the dynamics of the biomass of phytoplankton. It has been shown that in different types of lakes of East Antarctica under severe climate conditions under light and biogenic limitation, redistribution of autotrophic components in the formation of the biota of water bodies occurs: against the background of a decrease in the abundance and diversity of phytoplankton, the role of microphytobenthos and periphyton increases.

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.

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