The impacts of century-old, arsenic-rich mine tailings on multi-trophic level biological assemblages in lakes from Cobalt (Ontario, Canada).

Autor: Little AJ; Department of Geography and Environmental Studies, Carleton University, Ottawa K1S 5B6, Canada. Electronic address: amanda.little@carleton.ca., Sivarajah B; Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen's University, Kingston K7L 3N6, Canada., Frendo C; Institute for Environmental and Interdisciplinary Sciences, Carleton University, Ottawa K1S 5B6, Canada., Sprague DD; Department of Earth Sciences, Carleton University, Ottawa K1S 5B6, Canada., Smol JP; Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen's University, Kingston K7L 3N6, Canada., Vermaire JC; Department of Geography and Environmental Studies, Carleton University, Ottawa K1S 5B6, Canada; Institute for Environmental and Interdisciplinary Sciences, Carleton University, Ottawa K1S 5B6, Canada.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2020 Mar 20; Vol. 709, pp. 136212. Date of Electronic Publication: 2019 Dec 20.
DOI: 10.1016/j.scitotenv.2019.136212
Abstrakt: Silver mining in the early-1900s has left a legacy of arsenic-rich mine tailings around the town of Cobalt, in northeastern Ontario, Canada. Due to a lack of environmental control and regulations at that time, it was common for mines to dispose of their waste into adjacent lakes and land depressions, concentrating metals and metalloids in sensitive aquatic ecosystems. In order to examine what impacts, if any, these century-old, arsenic-rich mine tailings are having on present-day aquatic ecosystems, we sampled diatom assemblages in lake surface sediment in 24 lakes along a gradient of surface water arsenic contamination (0.4-972 μg/L). In addition, we examined sedimentary Cladocera and chironomid abundances and community composition, as well as open-water zooplankton communities and chlorophyll-a concentrations in10 of these study lakes along a gradient of arsenic contamination (0.9-1113 μg/L). Our results show that present-day arsenic concentration is not a significant driver of biotic community composition of the organisms we studied, but instead, that other variables such as lake depth and pH were more important in structuring assemblages. These results suggest that, while legacy contamination has greatly increased metal concentration beyond historical conditions, variability in lake-specific controls among the study lakes appear to be more important in the structuring of diatom, Cladocera, chironomidae, and zooplankton in these lakes.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: