Biological responses to permafrost thaw slumping in Canadian Arctic lakes

2012 ◽  
Vol 58 (2) ◽  
pp. 337-353 ◽  
Author(s):  
JOSHUA R. THIENPONT ◽  
KATHLEEN M. RÜHLAND ◽  
MICHAEL F. J. PISARIC ◽  
STEVEN V. KOKELJ ◽  
LINDA E. KIMPE ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Arctic Lakes ◽  
Permafrost Thaw ◽  
Biological Responses

The effects of isolation and colonization history on the genetic structure of marine-relict populations of Atlantic cod (Gadus morhua) in the Canadian Arctic

2006 ◽  
Vol 63 (8) ◽  
pp. 1830-1839 ◽  
Author(s):  
David C Hardie ◽  
Roxanne M Gillett ◽  
Jeffrey A Hutchings
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Allelic Diversity ◽  
Canadian Arctic ◽  
Environmental Stochasticity ◽  
Arctic Lakes ◽  
The Arctic ◽  
Effective Population ◽  
Eastern Canada ◽  
High Allelic Diversity

The genetic consequences of extended periods at low population size are fundamental to the conservation of depleted species such as the Atlantic cod (Gadus morhua). We compared microsatellite genetic variability among cod populations in Canadian Arctic lakes with that of Gilbert Bay resident and inshore cod from eastern Canada. The Arctic populations had the lowest genetic diversity and were the most strongly genetically structured and distinct. By contrast, eastern Canadian samples expressed high allelic diversity and were not significantly genetically structured or distinct relative to each other, whereas Gilbert Bay resident cod were intermediate to the Arctic and eastern Canadian groups. Our results are consistent with the hypothesis that the Arctic populations were colonized between 8000 and 5000 years ago and have experienced little or no gene flow since that time. Despite isolation at the extreme of the species' range, the Arctic populations have retained relatively high heterozygosities and high genetic effective population sizes relative to census sizes (Ne–Nc ratios). Potential explanations for this include the absence of fishing pressure, allowing for the persistence of large, highly fecund individuals, as well as biotic (e.g., absence of planktivores) and abiotic (e.g., low environmental stochasticity) factors in the Arctic lakes that minimize individual variance in reproductive success.

The Ecology of Atlantic Cod (Gadus morhua) in Canadian Arctic Lakes

ARCTIC ◽  
2011 ◽  
Vol 64 (2) ◽  
Author(s):  
David C. Hardie ◽  
Jeffrey A. Hutchings
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Canadian Arctic ◽  
Arctic Lakes

Recent climate warming favours more specialized cladoceran taxa in western Canadian Arctic lakes

2015 ◽  
Vol 42 (8) ◽  
pp. 1553-1565 ◽  
Author(s):  
Joshua R. Thienpont ◽  
Jennifer B. Korosi ◽  
Elisa S. Cheng ◽  
Kayla Deasley ◽  
Michael F. J. Pisaric ◽  
...  
Keyword(s):  
Climate Warming ◽  
Canadian Arctic ◽  
Arctic Lakes ◽  
Recent Climate

Distribution of Chironomidae (Insecta: Diptera) Head Capsules in Recent Sediments of Canadian Arctic Lakes

Hydrobiologia ◽  
2005 ◽  
Vol 549 (1) ◽  
pp. 131-143 ◽  
Author(s):  
K. Gajewski ◽  
G. Bouchard ◽  
S.E. Wilson ◽  
J. Kurek ◽  
L.C. Cwynar
Keyword(s):  
Canadian Arctic ◽  
Arctic Lakes ◽  
Recent Sediments

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.

Changes in water quality related to permafrost thaw may significantly impact zooplankton in small Arctic lakes

2020 ◽  
Vol 30 (8) ◽  
Author(s):  
Jasmina M. Vucic ◽  
Derek K. Gray ◽  
Rachel S. Cohen ◽  
Maariyah Syed ◽  
Alyssa D. Murdoch ◽  
...  
Keyword(s):  
Water Quality ◽  
Arctic Lakes ◽  
Permafrost Thaw

Holocene Environmental Changes in Lily Lake, Minnesota Inferred from Fossil Diatom and Pollen Assemblages

1988 ◽  
Vol 30 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Richard B. Brugam ◽  
Eric C. Grimm ◽  
Nancy M. Eyster-Smith
Keyword(s):  
Surface Sediment ◽  
Vegetation Change ◽  
Environmental Changes ◽  
Canadian Arctic ◽  
Late Glacial ◽  
Arctic Lakes ◽  
Diatom Assemblages ◽  
The Core ◽  
Water Lake ◽  
Soft Water Lake

A postglacial core was taken from Lily Lake, a soft-water lake, located on carbonate-poor till in eastern Minnesota. Pollen analysis allowed the reconstruction of watershed vegetation change. Diatom assemblages from the core were compared with 255 surface sediment assemblages from Minnesota, Maine, Labrador, and the Canadian arctic. Late-glacial assemblages were similar to Canadian arctic lakes. During the mid-postglacial period of warmer and drier climate, fossil diatom assemblages at Lily Lake were similar to those in the surface sediment of modern eutrophic hardwater lakes in Central Minnesota. The shift to hardwater diatom assemblages coincided with a shift to prairie species in fossil pollen assemblages at about 8000 yr B.P. At about 3400 year B.P. the fossil diatom assemblage that characterized presettlement times was established.

Environmental variables associated with littoral macroinvertebrate community composition in Arctic lakes

2020 ◽  
pp. 1-14
Author(s):  
Rachel S. Cohen ◽  
Derek K. Gray ◽  
Jasmina M. Vucic ◽  
Alyssa D. Murdoch ◽  
Sapna Sharma
Keyword(s):  
Chlorophyll A ◽  
Environmental Variables ◽  
Environmental Gradients ◽  
Road Dust ◽  
Arctic Lakes ◽  
Macroinvertebrate Communities ◽  
Lake Ecosystems ◽  
Permafrost Thaw ◽  
Selection Of Variables ◽  
Road Development

The relationship between littoral macroinvertebrate communities and environmental gradients in Arctic lakes is poorly understood, making it difficult to predict whether these important components of lake ecosystems will be affected by emerging stressors such as permafrost thaw and road development. To better understand how littoral macroinvertebrates are related to environmental gradients, we characterized macroinvertebrate communities and environmental variables for 32 Arctic lakes across the boreal–tundra transition in the Northwest Territories. Our analysis showed that a small selection of variables had strong relationships with community structure: calcium, conductivity, latitude, surface area, catchment area, percent fine sediment, chlorophyll a, and whitefish (Coregonus clupeaformis or Coregonus nasus) presence. Many of these variables, including calcium, conductivity, and chlorophyll a levels, are affected by permafrost thaw and road dust contamination. Based on the direction and magnitude of these relationships, we hypothesize that macroinvertebrate abundance might decline in response to permafrost thaw and road dust contamination, while taxon diversity may rise. While correlative in nature, our results and hypotheses may be valuable as future studies evaluate ongoing changes in Canada’s Arctic lakes.

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