GEOSCAN Search Results: Fastlink


TitleLacustrine Arcellinida (Testate Lobose Amoebae) as bioindicators of arsenic concentrations within the Yellowknife City Gold Project, Northwest Territories, Canada
AuthorRiou, L; Nasser, N A; Patterson, R T; Gregory, B R B; Galloway, J MORCID logo; Falck, H; Sexton, A
SourceLimnologica vol. 87, 2021 p. 1-11,
Alt SeriesNatural Resources Canada, Contribution Series 20200748
Mediapaper; on-line; digital
File formatpdf
ProvinceNorthwest Territories
NTS85J/07; 85J/08; 85J/09; 85J/10
Lat/Long WENS-113.5000 -113.0000 62.7500 62.2500
Subjectsenvironmental geology; geochemistry; hydrogeology; Nature and Environment; Science and Technology; Economics and Industry; lake sediment geochemistry; arsenic geochemistry; calcium geochemistry; iron geochemistry; strontium geochemistry; lake water depths; mining; statistical analyses; mass spectrometer analysis; faunal assemblages; Yellowknife City Gold Project; Giant Mine; Arcellinida; Amoebae; lacustrine sediments; Contaminated sites
Illustrationslocation maps; plots
ProgramEnvironmental Geoscience Mackenzie River
Released2021 03 01
AbstractArcellinida (testate lobose amoebae) were examined in near-surface sediment samples from 30 lakes located within the Gold Terra Resource Corporation (GTRC) Yellowknife City Gold Project, Northwest Territories, Canada, to assess the applicability of using the group as a robust tool to assess Arsenic (As) contamination. Lake contamination by As is of concern in the Yellowknife area because it is derived from geogenic (bedrock) and anthropogenic sources (legacy pollution from former mining operations, particularly the Giant Mine [1948-2004]). Statistical multivariate analyses (cluster analysis, non-metric multidimensional scaling [NMDS], and redundancy analysis [RDA]) were performed on geochemical (inductively coupled plasma mass spectrometry [ICP-MS]) and organic (loss-on-ignition) data to identify geochemical and hydrogeological controls on the arcellinidan distribution in the lakes. Cluster analysis and NMDS identified three distinct faunal assemblages: 1) Elevated Arsenic Assemblage (EAA; Approximately Unbiased (AU) p-value = 97%; median As = 272.4 mg/kg, range = 42-1353 mg/kg ; n = 9); 2) Centropyxid-Dominated Assemblage (CDA; AU p-value = 87%; median As = 169.7 mg/kg , range 60-233 mg/kg ; n = 9); and, 3) Difflugiid-Dominated Assemblage (DDA; AU p-value = 95%; median As = 61.3 mg/kg , range = 16-316 mg/kg ; n = 12). Six statistically significant controls on assemblage structure were identified using RDA. These were As, calcium, iron, strontium, water depth, and total organic carbon (Arcellinida variance explained = 36.2%) - As is the most significant control (12.2%; p-value < 0.002). Stress-tolerant centropyxids dominate in lakes characterized by elevated sedimentary As concentrations (64% centropyxids in EAA; 40% centropyxids in CDA), while stress-sensitive taxa thrived in samples associated with lower As concentrations (DDA). Our results corroborate the findings of previous Arcellinida studies in subarctic Canada and confirms the reliability of using Arcellinida as a reconnaissance tool for tracking As contamination in impacted lakes.
Summary(Plain Language Summary, not published)
Arcellinida (testate lobose amoebae) preserved in near-surface sediments of 30 lakes in the Gold Terra Resource Corporation Yellowknife City Gold Project, Northwest Territories, were examined. Bulk whole sediment geochemistry was also measured. Distinct assemblages of Arcellinida are controlled by sedimentary As concentration. Secondary controls include Ca, Fe, Sr, water depth, and TOC. Collectively, these variables and As explain 36.2% of variance in Arcellinida assemblages (determined by Redundancy Analaysis).

Date modified: