Abstract
We investigated the impacts of the Mount Polley tailings impoundment failure on chemical, physical, and microbial properties of substrates within the affected watershed, comprised of 70 hectares of riparian wetlands and 40 km of stream and lake shore. We established a biomonitoring network in October of 2014, two months following the disturbance, and evaluated riparian and wetland substrates for microbial community composition and function via 16S and full metagenome sequencing. A total of 234 samples were collected from substrates at 3 depths and 1,650,752 sequences were recorded in a geodatabase framework. These data revealed a wealth of information regarding watershed-scale distribution of microbial community members, as well as community composition, structure, and response to disturbance. Substrates associated with the impact zone were distinct chemically as indicated by elevated pH, nitrate, and sulphate. The microbial community exhibited elevated metabolic capacity for selenate and sulfate reduction and an abundance of chemolithoautotrophs in the Thiobacillus thiophilus/T. denitrificans/T. thioparus clade that may contribute to nitrate attenuation within the affected watershed. The most impacted area (a 6 km stream connecting two lakes) exhibited 30% lower microbial diversity relative to the remaining sites. The tailings impoundment failure at Mount Polley Mine has provided a unique opportunity to evaluate functional and compositional diversity soon after a major catastrophic disturbance to assess metabolic potential for ecosystem recovery.
Highlights
Mining produces large quantities of waste material annually, and containment failures present challenges to water quality and wildlife
We addressed disturbance of the structure and function of riparian soil and sediment microbial communities in the path of dispersed tailings and in non-impacted sites two months following the failure of a tailings storage facility at Mount Polley Mine, (Likely, BC Canada)
Hazeltine Creek exhibited the greatest impact from the disturbance, with the depth of erosion of soil and parent material exceeding 7 m in some areas, exposing bedrock and depositing thick (~1-3m) tailings and associated sands in a corridor ranging from 40–250 meters wide
Summary
Mining produces large quantities of waste material annually, and containment failures present challenges to water quality and wildlife. Watershed-scale microbial monitoring partner industry (Mount Polley Mining Corp) that contributed substantially to the development of the project (in the form of site access, feasibility assessment, material support, and manuscript review). NSERC monitored changes in the proposed project scope by requesting reports, but did not contribute to the content of the study directly. Genome BC and Genome Canada supported the project through funding and consultation on project scope/applicability/ suitability with respect to the use of genomics technologies and accomplishment of project goals, which served to improve project precisions/ outcomes. Project funding web references: Mitacs (https://www.mitacs.ca/en/impact/postdoctoralfellows-share-program-benefits-mitacs-elevateretreat); Genome BC Project funding web references: Mitacs (https://www.mitacs.ca/en/impact/postdoctoralfellows-share-program-benefits-mitacs-elevateretreat); Genome BC (https://www.genomecanada. ca/en/metagenomics-assess-impacts-mountpolley-mine-taillings-dam-breach-associatedecosystems); Genome Canada (https://www. genomecanada.ca/en/metagenomics-assessimpacts-mount-polley-mine-taillings-dam-breachassociated-ecosystems); Mount Polley Mine (https://www.imperialmetals.com/assets/docs/mtpolley/2015-02-23_MPFN.pdf)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
