Ecologie des communautés microbiennes dans des mines abandonnées et submergées ou la vie après l'extraction
Mining is an important and historical socio-economic resource in Quebec and Canada, which has created wealth and employment. Since the 19th century, ore deposits have largely contributed to the economy of Canadian provinces including Quebec. However, this exploitation has often led to the destruction of natural habitats, and the disturbance of underground ecosystems. In most cases, at the end of their exploitation, mines are simply abandoned without any environmental restoration, even if numerous Canadian Provinces have a detailed regulatory legislation on this issue. In 2020, the province of Quebec alone possessed 223 abandoned mines1, sites where activity has ceased indefinitely, with no known or solvent companies responsible. The province, and thus all Quebecois, then inherits these sites and becomes responsible for restoring these environments, which is a costly and complex process1. Until recently, when mines halt their activities, they are completely flooded with groundwater, which invade the underground galleries, tunnels, and shafts created and excavated by humans. Over time, an emerging community of living organisms colonizes, adapts and takes possession of this new human-made aquatic habitat. However, there exists little to no information concerning the diversity of these communities, or the functioning of these novel artificial ecosystems. Therefore, the overall objectives of this research project are to analyze the ecology of communities found within two abandoned flooded mine sites (whose exploitation ceased in 1930 and 1942) and to better understand how life can resume in ecosystems disrupted by humans. To achieve these goals, the research team is composed of a microbial ecologist (Dr. Lazar, Quebec), a hydrogeochemist (Dr. Ponsin, Quebec), and an environmental anthropologist (Dr. Jaclin, Ontario).
The microbial communities which have colonized the submerged mine habitats have most likely lived in an enclosed ecosystem for decades. Therefore, these heavy metal-rich habitats probably host cells adapted to fighting the stress induced by metal toxicity. When harvested and cultivated, these strains could be used to detoxify other heavy metal contaminated sites, with many applications in biotechnology and benefits for remediating polluted and damaged environments. The technological dives are an intrinsic aspect of this research project. Indeed, it is impossible to send a robot to collect samples, as debris in the underground tunnels prevent the use of a surface-connected cable, and radio wave control would be impossible due to the depth. This project will develop and expand diving techniques in extreme conditions (PTO Exploration). Optimization of aquatic sample and data collection have an important environmental benefit, in terms of research on climate change, as well as economic benefits, as they have the potential to create employment in the technological sector. Finally, from a socio-cultural and political point of view, this project will help us better understand how life can resume in places damaged or destroyed by human-led extractive activities. The results of our study will provide a better framework for institutions in charge of restoring abandoned mining sites.