title: Lacustrine Arcellinina (Testate Amoebae) as Bioindicators of Arsenic Contamination.
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 < 0.10). Stress-indicating species (primarily centropyxids) characterized the faunas of samples with high As concentrations (median = 121.7 ppm, max > 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.
authors.affiliation: Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6, Canada. Nawafnasser@cmail.carleton.ca.
authors.forename: Nawaf A
authors.initials: NA
authors.lastname: Nasser
authors.affiliation: Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6, Canada.
authors.forename: R Timothy
authors.initials: RT
authors.lastname: Patterson
authors.affiliation: School of Geography, Archaeology and Palaeoecology, Queen's University, Belfast, BT7 1NN, UK.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Roe
authors.affiliation: Geological Survey of Canada, Calgary, Alberta, T2L 2A7, Canada.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Galloway
authors.affiliation: Northwest Territories Geological Survey, Yellowknife, Northwest Territories, X1A 2L9, Canada.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Falck
authors.affiliation: Cumulative Impact Monitoring Program, Government of the Northwest Territories, Yellowknife, Northwest Territories, X1A 2L9, Canada.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Palmer
authors.affiliation: Environment Canada-Saskatoon, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Spence
authors.affiliation: Geological Survey of Canada, Calgary, Alberta, T2L 2A7, Canada.
authors.forename: Hamed
authors.initials: H
authors.lastname: Sanei
authors.affiliation: Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6, Canada.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Macumber
authors.affiliation: Geological Survey of Canada, Calgary, Alberta, T2L 2A7, Canada.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Neville
mesh_terms: D000656:Amoeba / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001151:Arsenic / Q000032:analysis*; D000077237:Arsenic Trioxide; D001152:Arsenicals; D002170:Canada; D016000:Cluster Analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D006046:Gold; D060106:Lakes / Q000737:chemistry; D008906:Mining; D010087:Oxides
chemical_list: D001152:Arsenicals; D010087:Oxides; D006046:Gold; D001151:Arsenic; D000077237:Arsenic Trioxide
keywords: Arcellinina; Arsenic; Contamination; Gold mine; Multivariate analysis; Northwest Territories