NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: physical sciences, water quality, rare earth element, aquatic toxicology

Objective(s): To develop data on the aquatic toxicology of rare earth elements in northern ecosystems and to contribute to water quality criteria for these metals.

Project Description: This licence has been issued for the scientific research application No.5300. The objectives of the project are to develop data on the aquatic toxicology of rare earth elements in northern ecosystems and to contribute to water quality criteria for these metals. Three types of sample collections are proposed: 1) Water samples of approximately 0.5 L will be collected in pre-cleaned bottles for water quality measurements (e.g. pH, dissolved organic matter, conductivity, hardness, phosphate, sulphate, chloride, turbidity, Cu, and etc.). Collections could be done at 15 to 20 sites in order to identify a subset of locations where more detailed sampling would be done; 2) Samples of aquatic invertebrates will be collected from shoreline vegetation and shallow substrates. The sampling method will be similar to those used for environmental monitoring, standard "kick-and-sweep" using 450 micron D shaped nets. Sampling is expected to be less disruptive than standard environmental monitoring as the area covered will be smaller, a few square meters at most. Biota sampled will be sorted on the shore to identify daphnids and amphipods which will be saved and the other organisms returned to their environment. The saved organisms will be transported to the lab for subsequent detailed identification, culture and testing in order to assess sensitivity to rare earth elements; and 3) Sites rich in dissolved organic matter (dark, "tea" coloured waters) will be sampled in order to collect and characterize the organic matter. In these collections a small submersible pump, a portable Reverse Osmosis (RO) system and a small generator are used. Water is drawn from the local source and passed through the RO system where the organic matter is separated from the water. Typically 250 L of water is filtered under pressure to produce 5-10 L of concentrated organic matter. The 240+ L of pure water is unchanged (no additives or chemicals are used) and is returned to the source. The concentrated organic matter will be refrigerated and taken to the lab for detailed characterization. Organic matter has many important functions within aquatic ecosystems and our previous research as demonstrated that different sources can have very unique properties. The research team are very interested to compare NWT sources with other sources, particularly with respect to their influence on rare earth element bioavailability and impact. The generator and RO systems limit sampling sites to those accessible by road and often they can stay on the truck. If sites are chosen where it is necessary to bring the generator and equipment onto the ground a plastic tarp will be used under the generator to contain any spills (e.g. when filling the tank with gas). The project results will be communicated under the umbrella of the Government of the Northwest Territories/Wilfred Laurier University Agreement. Opportunities to present finding at workshop will be developed through the science activities facilitated by the Agreement. Results are also reported annually to Environment Canada as part of their funding agreement and these could be made available to those interested. Publications and graduate thesis will be available online via Wilfrid Laurier University. If there is interest within local communities the team would welcome opportunities to listen to and work towards understanding concerns about rare earth elements and mining as well as discuss research plans to ensure that concerns are addressed. The fieldwork for this study will be conducted from August 4, 2022 to October 30, 2022