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Lacustrine Arcellinina (Testate Amoebae) as Bioindicators of Arsenic Contamination.

https://arctichealth.org/en/permalink/ahliterature271254
Source
Microb Ecol. 2016 Mar 30;
Publication Type
Article
Date
Mar-30-2016
Author
Nawaf A Nasser
R Timothy Patterson
Helen M Roe
Jennifer M Galloway
Hendrik Falck
Michael J Palmer
Christopher Spence
Hamed Sanei
Andrew L Macumber
Lisa A Neville
Source
Microb Ecol. 2016 Mar 30;
Date
Mar-30-2016
Language
English
Publication Type
Article
Abstract
Arcellininids (testate amoebae) were examined from 61 surface sediment samples collected from 59 lakes in the vicinity of former gold mines, notably Giant Mine, near Yellowknife, Northwest Territories, Canada to determine their utility as bioindicators of arsenic (As), which occurs both as a byproduct of gold extraction at mines in the area and ore-bearing outcrops. Cluster analysis (Q-R-mode) and detrended correspondence analysis (DCA) reveal five arcellininid assemblages, three of which are related to varying As concentrations in the sediment samples. Redundancy analysis (RDA) showed that 14 statistically significant environmental parameters explained 57 % of the variation in faunal distribution, while partial RDA indicated that As had the greatest influence on assemblage variance (10.7 %; p??10000 ppm, min?=?16.1 ppm, n?=?32), while difflugiid dominated assemblages were prevalent in substrates with relatively low As concentrations (median?=?30.2 ppm, max?=?905.2 ppm, min?=?6.3 ppm, n?=?20). Most of the lakes with very high As levels are located downwind (N and W) of the former Giant Mine roaster stack where refractory ore was roasted and substantial quantities of As were released (as As2O3) to the atmosphere in the first decade of mining. This spatial pattern suggests that a significant proportion of the observed As, in at least these lakes, are industrially derived. The results of this study highlight the sensitivity of Arcellinina to As and confirm that the group has considerable potential for assessing the impact of As contamination on lakes.
PubMed ID
27026100 View in PubMed
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Late Holocene climatic variability in Subarctic Canada: Insights from a high-resolution lake record from the central Northwest Territories.

https://arctichealth.org/en/permalink/ahliterature292541
Source
PLoS One. 2018; 13(6):e0199872
Publication Type
Journal Article
Date
2018
Author
April S Dalton
R Timothy Patterson
Helen M Roe
Andrew L Macumber
Graeme T Swindles
Jennifer M Galloway
Jesse C Vermaire
Carley A Crann
Hendrik Falck
Author Affiliation
Ottawa-Carleton Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Canada.
Source
PLoS One. 2018; 13(6):e0199872
Date
2018
Language
English
Publication Type
Journal Article
Abstract
We examined late Holocene (ca. 3300 yr BP to present-day) climate variability in the central Northwest Territories (Canadian Subarctic) using a diatom and sedimentological record from Danny's Lake (63.48ºN, 112.54ºW), located 40 km southwest of the modern-day treeline. High-resolution sampling paired with a robust age model (25 radiocarbon dates) allowed for the examination of both lake hydroecological conditions (30-year intervals; diatoms) and sedimentological changes in the watershed (12-year intervals; grain size records) over the late Holocene. Time series analysis of key lake ecological indicators (diatom species Aulacoseira alpigena, Pseudostaurosira brevistriata and Achnanthidium minutissimum) and sedimentological parameters, reflective of catchment processes (coarse silt fraction), suggests significant intermittent variations in turbidity, pH and light penetration within the lake basin. In the diatom record, we observed discontinuous periodicities in the range of ca. 69, 88-100, 115-132, 141-188, 562, 750 and 900 years (>90% and >95% confidence intervals), whereas the coarse silt fraction was characterized by periodicities in the >901 and 95% confidence interval). Periodicities in the proxy data from the Danny's Lake sediment core align with changes in total solar irradiance over the past ca. 3300 yr BP and we hypothesize a link to the Suess Cycle, Gleissberg Cycle and Pacific Decadal Oscillation via occasional inland propagation of shifting air masses over the Pacific Ocean. This research represents an important baseline study of the underlying causes of climate variability in the Canadian Subarctic and provides details on the long-term climate variability that has persisted in this region through the past three thousand years.
Notes
Cites: Biol Rev Camb Philos Soc. 2015 May;90(2):522-41 PMID 24917134
Cites: Proc Natl Acad Sci U S A. 2005 Mar 22;102(12):4397-402 PMID 15738395
Cites: Ann Rev Mar Sci. 2010;2:115-43 PMID 21141660
Cites: Proc Natl Acad Sci U S A. 2004 Mar 23;101(12):4136-41 PMID 15016919
Cites: Sci Rep. 2014 Jan 09;4:3611 PMID 24402348
PubMed ID
29953559 View in PubMed
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Late Holocene climatic variability in Subarctic Canada: Insights from a high-resolution lake record from the central Northwest Territories.

https://arctichealth.org/en/permalink/ahliterature296859
Source
PLoS One. 2018; 13(6):e0199872
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
2018
Author
April S Dalton
R Timothy Patterson
Helen M Roe
Andrew L Macumber
Graeme T Swindles
Jennifer M Galloway
Jesse C Vermaire
Carley A Crann
Hendrik Falck
Author Affiliation
Ottawa-Carleton Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Canada.
Source
PLoS One. 2018; 13(6):e0199872
Date
2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Canada
Climate change
Diatoms
Fossils
Lakes
Abstract
We examined late Holocene (ca. 3300 yr BP to present-day) climate variability in the central Northwest Territories (Canadian Subarctic) using a diatom and sedimentological record from Danny's Lake (63.48ºN, 112.54ºW), located 40 km southwest of the modern-day treeline. High-resolution sampling paired with a robust age model (25 radiocarbon dates) allowed for the examination of both lake hydroecological conditions (30-year intervals; diatoms) and sedimentological changes in the watershed (12-year intervals; grain size records) over the late Holocene. Time series analysis of key lake ecological indicators (diatom species Aulacoseira alpigena, Pseudostaurosira brevistriata and Achnanthidium minutissimum) and sedimentological parameters, reflective of catchment processes (coarse silt fraction), suggests significant intermittent variations in turbidity, pH and light penetration within the lake basin. In the diatom record, we observed discontinuous periodicities in the range of ca. 69, 88-100, 115-132, 141-188, 562, 750 and 900 years (>90% and >95% confidence intervals), whereas the coarse silt fraction was characterized by periodicities in the >901 and 95% confidence interval). Periodicities in the proxy data from the Danny's Lake sediment core align with changes in total solar irradiance over the past ca. 3300 yr BP and we hypothesize a link to the Suess Cycle, Gleissberg Cycle and Pacific Decadal Oscillation via occasional inland propagation of shifting air masses over the Pacific Ocean. This research represents an important baseline study of the underlying causes of climate variability in the Canadian Subarctic and provides details on the long-term climate variability that has persisted in this region through the past three thousand years.
PubMed ID
29953559 View in PubMed
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Organic matter control on the distribution of arsenic in lake sediments impacted by ~65years of gold ore processing in subarctic Canada.

https://arctichealth.org/en/permalink/ahliterature286986
Source
Sci Total Environ. 2017 Oct 27;
Publication Type
Article
Date
Oct-27-2017
Author
Jennifer M Galloway
Graeme T Swindles
Heather E Jamieson
Michael Palmer
Michael B Parsons
Hamed Sanei
Andrew L Macumber
R. Timothy Patterson
Hendrik Falck
Source
Sci Total Environ. 2017 Oct 27;
Date
Oct-27-2017
Language
English
Publication Type
Article
Abstract
Climate change is profoundly affecting seasonality, biological productivity, and hydrology in high northern latitudes. In sensitive subarctic environments exploitation of mineral resources led to contamination and it is not known how cumulative effects of resource extraction and climate warming will impact ecosystems. Gold mines near Yellowknife, Northwest Territories, subarctic Canada, operated from 1938 to 2004 and released >20,000t of arsenic trioxide (As2O3) to the environment through stack emissions. This release resulted in elevated arsenic concentrations in lake surface waters and sediments relative to Canadian drinking water standards and guidelines for the protection of aquatic life. A meta-analytical approach is used to better understand controls on As distribution in lake sediments within a 30-km radius of historic mineral processing activities. Arsenic concentrations in the near-surface sediments range from 5mg·kg(-1) to over 10,000mg·kg(-1) (median 81mg·kg(-1); n=105). Distance and direction from the historic roaster stack are significantly (p
PubMed ID
29111252 View in PubMed
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