NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: physical sciences, water sampling, water chemistry, freshwater, carbon dynamics

Objective(s): To improve the quantitative understanding of carbon dynamics in Canadian subarctic freshwaters, with a focus on identifying the processes governing the balance between carbon sinks and carbon sources to the atmosphere.

Project Description: This licence has been issued for the scientific research application No.4703. The objective is to improve the quantitative understanding of carbon dynamics in Canadian subarctic freshwaters, with a focus on identifying the processes governing the balance between carbon sinks and carbon sources to the atmosphere. The research team will pair field-based observations with laboratory experiments to gain knowledge on the processes that control carbon fate and cycling within subarctic taiga shield surface waters. Samples will be collected along a latitudinal gradient (Yellowknife, Wekweètì, and Daring Lake) to represent differences in climate, vegetation, and permafrost encountered in the subarctic taiga shield. These lakes have been previously studied and are relatively simple to get to. This allows the team to continue to collect and provide long-term data for these locations. Sampling will occur during the winter, spring, and late summer/fall to understand how these systems evolve over the year. The research team will use geochemical and stable isotope techniques to understand different carbon sources and processes in various lakes and ponds. Subsurface water will also be collected to identify the chemical composition of water draining from the land. In the field the research team will collect a suite of water quality parameters to understand the variability across a number of lakes: nutrients (dissolved organic and inorganic nitrogen, total and dissolved phosphorus), chlorophyll-a, temperature, dissolved oxygen, specific conductance, pH, and dissolved metals. The team will measure the stable isotopes of water, dissolved organic and inorganic carbon, and particulate organic carbon to quantify differences in carbon source and processing within the water column. Laboratory experiments will be conducted to quantify how easily carbon degrades via sunlight and microbes, and how these degradation processes influence our measures of water and carbon quality. The research team plan to pair the field excursions with an opportunity to meet and have discussions with NWT stakeholders and community members. In particular, the Co-PI (Michael English) has had extensive experience working with the community of Wekweètì on a number of projects. The team will continue to build on this relationship with plans to host a ‘Feast’ during the last yearly trip (generally in August) to provide updates and allow for a conversation on science in the community and to learn from local knowledge about changes in lake levels over the years. The team will also strive to leverage any funding opportunities to return to the community and provide updates and timelines of the work. While away from the community, the team plan to create an update newsletter that informs the community of the objectives, work, and sampling locations (in both English and Tli?cho). One of the community members works with the team in the. The fieldwork for this study will be conducted from August 4, 2021 to December 31, 2021.