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13 records – page 1 of 2.

Arsenic bioaccumulation in subarctic fishes of a mine-impacted bay on Great Slave Lake, Northwest Territories, Canada.

https://arctichealth.org/en/permalink/ahliterature302703
Source
PLoS One. 2019; 14(8):e0221361
Publication Type
Journal Article
Date
2019
Author
John Chételat
Peter A Cott
Maikel Rosabal
Adam Houben
Christine McClelland
Elise Belle Rose
Marc Amyot
Author Affiliation
Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada.
Source
PLoS One. 2019; 14(8):e0221361
Date
2019
Language
English
Publication Type
Journal Article
Abstract
A subarctic fish community in mine-impacted Yellowknife Bay (Great Slave Lake, Northwest Territories, Canada) was investigated for biological and ecological processes controlling arsenic bioaccumulation. Total concentrations of arsenic, antimony, and metals were measured in over 400 fishes representing 13 species, and primary producers and consumers were included to characterize food web transfer. Yellowknife Bay had slightly more arsenic in surface waters (~3 µg/L) relative to the main body of Great Slave Lake (
PubMed ID
31442230 View in PubMed
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Diet influences on growth and mercury concentrations of two salmonid species from lakes in the eastern Canadian Arctic.

https://arctichealth.org/en/permalink/ahliterature304422
Source
Environ Pollut. 2021 Jan 01; 268(Pt B):115820
Publication Type
Journal Article
Date
Jan-01-2021
Author
John Chételat
Yueting Shao
Murray C Richardson
Gwyneth A MacMillan
Marc Amyot
Paul E Drevnick
Hardeep Gill
Günter Köck
Derek C G Muir
Author Affiliation
Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, K1A 0H3, Canada. Electronic address: john.chetelat@canada.ca.
Source
Environ Pollut. 2021 Jan 01; 268(Pt B):115820
Date
Jan-01-2021
Language
English
Publication Type
Journal Article
Keywords
Animals
Arctic Regions
Canada
Diet
Environmental monitoring
Lakes
Mercury - analysis
Salmonidae
Water Pollutants, Chemical - analysis
Abstract
Diet, age, and growth rate influences on fish mercury concentrations were investigated for Arctic char (Salvelinus alpinus) and brook trout (Salvelinus fontinalis) in lakes of the eastern Canadian Arctic. We hypothesized that faster-growing fish have lower mercury concentrations because of growth dilution, a process whereby more efficient growth dilutes a fish's mercury burden. Using datasets of 57 brook trout and 133 Arctic char, linear regression modelling showed fish age and diet indices were the dominant explanatory variables of muscle mercury concentrations for both species. Faster-growing fish (based on length-at-age) fed at a higher trophic position, and as a result, their mercury concentrations were not lower than slower-growing fish. Muscle RNA/DNA ratios were used as a physiological indicator of short-term growth rate (days to weeks). Slower growth of Arctic char, inferred from RNA/DNA ratios, was found in winter versus summer and in polar desert versus tundra lakes, but RNA/DNA ratio was (at best) a weak predictor of fish mercury concentration. Net effects of diet and age on mercury concentration were greater than any potential offset by biomass dilution in faster-growing fish. In these resource-poor Arctic lakes, faster growth was associated with feeding at a higher trophic position, likely due to greater caloric (and mercury) intake, rather than growth efficiency.
PubMed ID
33120140 View in PubMed
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Gut Microbiome of the Canadian Arctic Inuit.

https://arctichealth.org/en/permalink/ahliterature279056
Source
mSphere. 2017 Jan-Feb;2(1)
Publication Type
Article
Author
Catherine Girard
Nicolas Tromas
Marc Amyot
B Jesse Shapiro
Source
mSphere. 2017 Jan-Feb;2(1)
Language
English
Publication Type
Article
Abstract
Diet is a major determinant of community composition in the human gut microbiome, and "traditional" diets have been associated with distinct and highly diverse communities, compared to Western diets. However, most traditional diets studied have been those of agrarians and hunter-gatherers consuming fiber-rich diets. In contrast, the Inuit of the Canadian Arctic have been consuming a traditional diet low in carbohydrates and rich in animal fats and protein for thousands of years. We hypothesized that the Inuit diet and lifestyle would be associated with a distinct microbiome. We used deep sequencing of the 16S rRNA gene to compare the gut microbiomes of Montrealers with a Western diet to those of the Inuit consuming a range of traditional and Western diets. At the overall microbial community level, the gut microbiomes of Montrealers and Inuit were indistinguishable and contained similar levels of microbial diversity. However, we observed significant differences in the relative abundances of certain microbial taxa down to the subgenus level using oligotyping. For example, Prevotella spp., which have been previously associated with high-fiber diets, were enriched in Montrealers and among the Inuit consuming a Western diet. The gut microbiomes of Inuit consuming a traditional diet also had significantly less genetic diversity within the Prevotella genus, suggesting that a low-fiber diet might not only select against Prevotella but also reduce its diversity. Other microbes, such as Akkermansia, were associated with geography as well as diet, suggesting limited dispersal to the Arctic. Our report provides a snapshot of the Inuit microbiome as Western-like in overall community structure but distinct in the relative abundances and diversity of certain genera and strains. IMPORTANCE Non-Western populations have been shown to have distinct gut microbial communities shaped by traditional diets. The hitherto-uncharacterized microbiome of the Inuit may help us to better understand health risks specific to this population such as diabetes and obesity, which increase in prevalence as many Inuit transition to a Western diet. Here we show that even Inuit consuming a mostly traditional diet have a broadly Western-like microbiome. This suggests that similarities between the Inuit diet and the Western diet (low fiber, high fat) may lead to a convergence of community structures and diversity. However, certain species and strains of microbes have significantly different levels of abundance and diversity in the Inuit, possibly driven by differences in diet. Furthermore, the Inuit diet provides an exception to the correlation between traditional diets and high microbial diversity, potentially due to their transitioning diet. Knowledge of the Inuit microbiome may provide future resources for interventions and conservation of Inuit heritage.
PubMed ID
28070563 View in PubMed
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High Methylmercury in Arctic and Subarctic Ponds is Related to Nutrient Levels in the Warming Eastern Canadian Arctic.

https://arctichealth.org/en/permalink/ahliterature263333
Source
Environ Sci Technol. 2015 Jun 12;
Publication Type
Article
Date
Jun-12-2015
Author
Gwyneth A MacMillan
Catherine Girard
John Chételat
Isabelle Laurion
Marc Amyot
Source
Environ Sci Technol. 2015 Jun 12;
Date
Jun-12-2015
Language
English
Publication Type
Article
Abstract
Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L(-1)). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3-2.2 ng L(-1)) than polygonal ponds (0.1-0.3 ng L(-1)) or lakes (
PubMed ID
26030209 View in PubMed
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Local fungi, willow and municipal compost effectively remediate petroleum-contaminated soil in the Canadian North.

https://arctichealth.org/en/permalink/ahliterature299109
Source
Chemosphere. 2019 Apr; 220:47-55
Publication Type
Journal Article
Date
Apr-2019
Author
Kawina Robichaud
Catherine Girard
Dimitri Dagher
Katherine Stewart
Michel Labrecque
Mohamed Hijri
Marc Amyot
Author Affiliation
Center for Northern Studies, Département de Sciences Biologiques, Université de Montréal, Pavillon Marie-Victorin, 90 Vincent d'Indy, Montréal QC, H2V 2S9, Canada.
Source
Chemosphere. 2019 Apr; 220:47-55
Date
Apr-2019
Language
English
Publication Type
Journal Article
Keywords
Biodegradation, Environmental
Canada
Composting
Fertilizers
Fungi - metabolism
Hydrocarbons - metabolism
Petroleum - metabolism
Salix - metabolism
Soil Microbiology
Soil Pollutants - isolation & purification - metabolism
Abstract
Low energy-input alternatives based on locally available products are needed for treating petroleum-hydrocarbon spills in northern regions. We tested the efficacy of three local biological components (municipal compost, white-rot fungus: Pleurotus ostreatus and willow: Salix planifolia) to remediate diesel-contaminated soils in a subarctic climate (Whitehorse, YT, Canada), and compared their efficacy to natural attenuation and chemical fertilizers (industry standard). After the first growing season, biologically amended treatments (BAT) that contained >2 biological components, had decreased 69-73% of the diesel's F2 fraction (C10-C16), which is more than natural attenuation or fertilizer (48 and 51%). By the third growing season, the BAT dropped below the Canadian Council of Ministers of the Environment's (CCME) Agricultural & Residential/Parkland guideline (
PubMed ID
30579173 View in PubMed
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Local fungi, willow and municipal compost effectively remediate petroleum-contaminated soil in the Canadian North.

https://arctichealth.org/en/permalink/ahliterature296947
Source
Chemosphere. 2018 Dec 15; 220:47-55
Publication Type
Journal Article
Date
Dec-15-2018
Author
Kawina Robichaud
Catherine Girard
Dimitri Dagher
Katherine Stewart
Michel Labrecque
Mohamed Hijri
Marc Amyot
Author Affiliation
Center for Northern Studies, Département de Sciences Biologiques, Université de Montréal, Pavillon Marie-Victorin, 90 Vincent d'Indy, Montréal QC, H2V 2S9, Canada.
Source
Chemosphere. 2018 Dec 15; 220:47-55
Date
Dec-15-2018
Language
English
Publication Type
Journal Article
Abstract
Low energy-input alternatives based on locally available products are needed for treating petroleum-hydrocarbon spills in northern regions. We tested the efficacy of three local biological components (municipal compost, white-rot fungus: Pleurotus ostreatus and willow: Salix planifolia) to remediate diesel-contaminated soils in a subarctic climate (Whitehorse, YT, Canada), and compared their efficacy to natural attenuation and chemical fertilizers (industry standard). After the first growing season, biologically amended treatments (BAT) that contained >2 biological components, had decreased 69-73% of the diesel's F2 fraction (C10-C16), which is more than natural attenuation or fertilizer (48 and 51%). By the third growing season, the BAT dropped below the Canadian Council of Ministers of the Environment's (CCME) Agricultural & Residential/Parkland guideline (
PubMed ID
30579173 View in PubMed
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Mercury in freshwater ecosystems of the Canadian Arctic: Recent advances on its cycling and fate.

https://arctichealth.org/en/permalink/ahliterature102698
Source
Sci Total Environ. 2014 Jun 30;
Publication Type
Article
Date
Jun-30-2014
Author
John Chételat
Marc Amyot
Paul Arp
Jules M Blais
David Depew
Craig A Emmerton
Marlene Evans
Mary Gamberg
Nikolaus Gantner
Catherine Girard
Jennifer Graydon
Jane Kirk
David Lean
Igor Lehnherr
Derek Muir
Mina Nasr
Alexandre J Poulain
Michael Power
Pat Roach
Gary Stern
Heidi Swanson
Shannon van der Velden
Source
Sci Total Environ. 2014 Jun 30;
Date
Jun-30-2014
Language
English
Publication Type
Article
Abstract
The Canadian Arctic has vast freshwater resources, and fish are important in the diet of many Northerners. Mercury is a contaminant of concern because of its potential toxicity and elevated bioaccumulation in some fish populations. Over the last decade, significant advances have been made in characterizing the cycling and fate of mercury in these freshwater environments. Large amounts of new data on concentrations, speciation and fluxes of Hg are provided and summarized for water and sediment, which were virtually absent for the Canadian Arctic a decade ago. The biogeochemical processes that control the speciation of mercury remain poorly resolved, including the sites and controls of methylmercury production. Food web studies have examined the roles of Hg uptake, trophic transfer, and diet for Hg bioaccumulation in fish, and, in particular, advances have been made in identifying determinants of mercury levels in lake-dwelling and sea-run forms of Arctic char. In a comparison of common freshwater fish species that were sampled across the Canadian Arctic between 2002 and 2009, no geographic patterns or regional hotspots were evident. Over the last two to four decades, Hg concentrations have increased in some monitored populations of fish in the Mackenzie River Basin while other populations from the Yukon and Nunavut showed no change or a slight decline. The different Hg trends indicate that the drivers of temporal change may be regional or habitat-specific. The Canadian Arctic is undergoing profound environmental change, and preliminary evidence suggests that it may be impacting the cycling and bioaccumulation of mercury. Further research is needed to investigate climate change impacts on the Hg cycle as well as biogeochemical controls of methylmercury production and the processes leading to increasing Hg levels in some fish populations in the Canadian Arctic.
PubMed ID
24993511 View in PubMed
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Mercury in the marine environment of the Canadian Arctic: Review of recent findings.

https://arctichealth.org/en/permalink/ahliterature102701
Source
Sci Total Environ. 2014 Jun 18;
Publication Type
Article
Date
Jun-18-2014
Author
Birgit Braune
John Chételat
Marc Amyot
Tanya Brown
Meredith Claydon
Marlene Evans
Aaron Fisk
Ashley Gaden
Catherine Girard
Alex Hare
Jane Kirk
Igor Lehnherr
Robert Letcher
Lisa Loseto
Robie Macdonald
Erin Mann
Bailey McMeans
Derek Muir
Nelson O'Driscoll
Alexandre Poulain
Ken Reimer
Gary Stern
Source
Sci Total Environ. 2014 Jun 18;
Date
Jun-18-2014
Language
English
Publication Type
Article
Abstract
This review summarizes data and information which have been generated on mercury (Hg) in the marine environment of the Canadian Arctic since the previous Canadian Arctic Contaminants Assessment Report (CACAR) was released in 2003. Much new information has been collected on Hg concentrations in marine water, snow and ice in the Canadian Arctic. The first measurements of methylation rates in Arctic seawater indicate that the water column is an important site for Hg methylation. Arctic marine waters were also found to be a substantial source of gaseous Hg to the atmosphere during the ice-free season. High Hg concentrations have been found in marine snow as a result of deposition following atmospheric mercury depletion events, although much of this Hg is photoreduced and re-emitted back to the atmosphere. The most extensive sampling of marine sediments in the Canadian Arctic was carried out in Hudson Bay where sediment total Hg (THg) concentrations were low compared with other marine regions in the circumpolar Arctic. Mass balance models have been developed to provide quantitative estimates of THg fluxes into and out of the Arctic Ocean and Hudson Bay. Several recent studies on Hg biomagnification have improved our understanding of trophic transfer of Hg through marine food webs. Over the past several decades, Hg concentrations have increased in some marine biota, while other populations showed no temporal change. Marine biota also exhibited considerable geographic variation in Hg concentrations with ringed seals, beluga and polar bears from the Beaufort Sea region having higher Hg concentrations compared with other parts of the Canadian Arctic. The drivers of these variable patterns of Hg bioaccumulation, both regionally and temporally, within the Canadian Arctic remain unclear. Further research is needed to identify the underlying processes including the interplay between biogeochemical and food web processes and climate change.
PubMed ID
24953756 View in PubMed
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Photodemethylation of Methylmercury in Eastern Canadian Arctic Thaw Pond and Lake Ecosystems.

https://arctichealth.org/en/permalink/ahliterature270724
Source
Environ Sci Technol. 2016 Apr 5;50(7):3511-20
Publication Type
Article
Date
Apr-5-2016
Author
Catherine Girard
Maxime Leclerc
Marc Amyot
Source
Environ Sci Technol. 2016 Apr 5;50(7):3511-20
Date
Apr-5-2016
Language
English
Publication Type
Article
Abstract
Permafrost thaw ponds of the warming Eastern Canadian Arctic are major landscape constituents and often display high levels of methylmercury (MeHg). We examined photodegradation potentials in high-dissolved organic matter (DOC) thaw ponds on Bylot Island (BYL) and a low-DOC oligotrophic lake on Cornwallis Island (Char Lake). In BYL, the ambient MeHg photodemethylation (PD) rate over 48 h of solar exposure was 6.1 × 10(-3) m(2) E(-1), and the rate in MeHg amended samples was 9.3 × 10(-3) m(2) E(-1). In contrast, in low-DOC Char Lake, PD was only observed in the first 12 h, which suggests that PD may not be an important loss process in polar desert lakes. Thioglycolic acid addition slowed PD, while glutathione and chlorides did not impact northern PD rates. During an ecosystem-wide experiment conducted in a covered BYL pond, there was neither net MeHg increase in the dark nor loss attributable to PD following re-exposure to sunlight. We propose that high-DOC Arctic thaw ponds are more prone to MeHg PD than nearby oligotrophic lakes, likely through photoproduction of reactive species rather than via thiol complexation. However, at the ecosystem level, these ponds, which are widespread through the Arctic, remain likely sources of MeHg for neighboring systems.
PubMed ID
26938195 View in PubMed
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Rare earth elements in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic.

https://arctichealth.org/en/permalink/ahliterature289905
Source
Environ Sci Process Impacts. 2017 Oct 18; 19(10):1336-1345
Publication Type
Journal Article
Date
Oct-18-2017
Author
Gwyneth Anne MacMillan
John Chételat
Joel P Heath
Raymond Mickpegak
Marc Amyot
Author Affiliation
Centre for Northern Studies, Department of Biological Sciences, University of Montreal, Montreal, QC, CanadaH2V 2S9. m.amyot@umontreal.ca.
Source
Environ Sci Process Impacts. 2017 Oct 18; 19(10):1336-1345
Date
Oct-18-2017
Language
English
Publication Type
Journal Article
Keywords
Animals
Arctic Regions
Canada
Carbon Isotopes - analysis
Ecosystem
Environmental Monitoring - methods
Environmental Pollutants - analysis
Food chain
Fresh Water - chemistry
Geologic Sediments - chemistry
Metals, Rare Earth - analysis
Mining
Nitrogen Isotopes - analysis
Seawater - chemistry
Abstract
Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environmental impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. Northern ecosystems are potentially vulnerable to REE enrichment from prospective mining projects at high latitudes. To understand how REEs behave in remote northern food webs, we measured REE concentrations and carbon and nitrogen stable isotope ratios (?15N, ?13C) in biota from marine, freshwater, and terrestrial ecosystems of the eastern Canadian Arctic (N = 339). Wildlife harvesting and tissue sampling was partly conducted by local hunters through a community-based monitoring project. Results show that REEs generally follow a coherent bioaccumulation pattern for sample tissues, with some anomalies for redox-sensitive elements (Ce, Eu). Highest REE concentrations were found at low trophic levels, especially in vegetation and aquatic invertebrates. Terrestrial herbivores, ringed seal, and fish had low total REE levels in muscle tissue (?REE for 15 elements
PubMed ID
28879355 View in PubMed
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13 records – page 1 of 2.