NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: contaminants, water quality, aquatic invertebrates, rare earth element

Objective(s): To evaluate the relative sensitivity of northern aquatic invertebrates and northern ecosystems in comparison to southern species and environments.

Project Description: The objectives of this research are to evaluate the relative sensitivity of northern aquatic invertebrates and northern ecosystems in comparison to southern species and environments. The focus of comparisons is in relation to the toxicity of rare earth elements. Three types of sample collections are proposed. These would be done at the Avalon Rare Metals Inc. Thor Lake site as well as along the Ingraham Trail (highway 4) east and also west of Yellowknife. The latter sites will be chose where there is easy road access to shallow wadeable waters (e.g. roadside and/or boat launch areas). Approximately 3 to 5 sites will be chosen for detailed samplings and examples could include (Pontoon Lake, Trappers Lake and Tibbitt Lake). 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 (as in 2 and 3 below). 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 samples 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 at Laurier for subsequent detailed identification, culture and side by side testing with southern species in order to compare sensitivities to rare earth elements. 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 L of concentrated organic matter. The 245 L of pure water is unchanged (no additives or chemicals are used) and is returned to the source. The 5 L of concentrated organic matter will be refrigerated and taken to the lab for detailed characterization. Organic matter has many important functions within aquatic ecosystems and the work on southern environments demonstrates that different sources can have very unique properties. The research team are very interested to compare these with northern organic matter sources. 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). This project is focused on learning about the potential impact of rare earth elements to sensitive aquatic organisms in northern environments. Currently there are very few studies on the toxicity of these elements but there is growing activity to develop mines, particularly in the north (e.g. the Avalon Rare Metals Inc. development at Thor Lake as well as in Quebec and N. Ontario). Most of the research activities for this project are lab studies (as required by environmental regulators) but the team are also very interested in the unique nature of northern ecosystems and how these differ from southern Canadian environments. Most of the data generated to derive Canadian Water Quality Guidelines is done in southern waters with southern species and whether (how well) Guidelines are relevant in northern waters is the goal. The project results will be communicated under the umbrella of the GNWT/WLU Agreement. Opportunities to present finding at workshops 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 theses will be available online via Wilfrid Laurier University. The fieldwork for this study will be conducted from August 20, 2015 to October 10, 2015.