The shift to sustainable energy is crucial for our future, but it requires a significant increase in the extraction of minerals and the generation of “green” electricity, such as hydroelectric power. These activities, often conducted on Indigenous lands, can have profound environmental impacts on lakes and rivers. The energy transition also demands new infrastructure, including a global fleet of electric vehicles and extensive wind and solar farms. This has already spurred a surge in demand for critical and strategic metals.
Given the national importance of ensuring a stable supply of these metals in a complex geopolitical landscape, many mineral-rich countries are keen to promote the development of new mines. In Canada and Québec, these mines are frequently located in the Canadian Shield, extending into the Far North, regions already susceptible to climate change.
For instance, several rare-earth element mining projects are being explored in the North. The first operational mine for these metals began production in 2021 near Great Slave Lake in the Northwest Territories, and similar projects are emerging in Nunavik. These mines, whether through tailings or atmospheric deposition, can introduce a mix of metals into aquatic ecosystems. Often, the concern is not the primary metal of interest but other metals, like radioactive uranium and thorium, which are inadvertently extracted alongside rare-earth elements.
The challenge of data deficiency
A significant challenge is the lack of comprehensive data on the ecotoxicology of these metals, complicating efforts to establish water quality criteria. As professors of biological sciences at Université de Montréal and Université du Québec à Montréal and experts in water quality, we are working to generate the necessary toxicological data. In a recent study, we measured naturally occurring concentrations of rare-earth elements in water and animals to understand the potential impacts of new mines.
We are also developing early detection tools for monitoring the environmental impact of critical and strategic metals. For example, we have used aquatic insect larvae and zooplankton as indicators for rare-earth elements in the environment. Our research indicates that the free ionic form of a metal often best explains its accumulation in animals, particularly when considering competing ions in solution that may affect metal uptake at biological entry points, like the gills of invertebrates.
These findings will help governmental agencies better predict the effects of future discharges of these increasingly important contaminants.
Hydroelectric power and its environmental impact
The energy transition requires a significant supply of electricity from non-fossil fuel sources. Hydroelectricity is a common choice, but it necessitates constructing new power stations on rivers. These stations can alter hydrological regimes and biodiversity, and they can promote the production of the neurotoxin methylmercury. This toxin is generated by microbes in low-oxygen environments, such as land flooded by dams or sediments at the bottom of reservoirs.
Our recent research shows that even small hydroelectric stations, such as run-of-the-river plants, can cause temporary increases in methylmercury levels in food webs, affecting large predatory fish and their consumers, including fish-eating birds and humans. Despite small hydro plants making up over 90% of the world’s power plants, their cumulative environmental impact could surpass that of larger reservoir plants. Additionally, land disturbances upstream of power plants, like forest fires and logging, can exacerbate neurotoxin production by increasing the transfer of mercury and organic matter to rivers.
Building partnerships with indigenous communities
Since many of these mines and power stations are located on Indigenous lands, it is crucial to build trust and establish communication with the communities living there. We have developed collaborative research projects involving First Peoples’ communities, industry, and universities. These projects prioritize the communities’ research interests, ensuring they receive results directly and benefit from knowledge transfer.
One way we facilitate this knowledge transfer is through educational initiatives, like knowledge camps, where young people engage in scientific activities with research teams and learn traditional knowledge from Elders. By working together with communities, industry, and governments, we aim to conduct inclusive research that monitors the impact of the energy transition on our lakes and rivers, promoting both progress and protection for all involved.
