Using Paleolimnology to Establish Baseline Conditions and Trends for Contaminants and Climate for a Community-based Aquatic Ecosystem Monitoring Program, Marian Watershed, Northwest Territories


PROJECT LEAD: Brent Wolfe (Laurier)
PROJECT TEAM MEMBERS: James V. Telford, MSc. Physical Geography Student (Laurier)

Roland Hall (University of Waterloo)

Jessica Hum (Lands Protection Department, Tłı̨chǫ Government)

PROJECT LOCATION: Tłı̨chǫ Lands, Behchokǫ̀

The Marian Watershed encompasses 22,000 km2 within the Tłı̨chǫ Lands. It is an important region supporting a strong Tłı̨chǫ heritage of hunting, fishing, and transportation through the waterway. This region, like many in the North, is affected by multiple stressors including climate change, which is altering sensitive ecosystems, and natural resource development such as mining activities that can be a potential source of pollution.

In response to community concerns regarding these issues, the Tłı̨chǫgovernment began the Marian Watershed Stewardship Program (MWSP), which aims to understand and monitor the aquatic ecosystems through the sampling of fish, water, and sediment. This project is being conducted in collaboration with the MWSP to establish baselines of sediment metals concentrations and aquatic ecosystem characteristics. With the use of sediment cores taken from multiple lakes throughout the watershed, long-term records of change in aquatic ecosystem conditions are being developed as well a record of variation in natural sediment metals concentrations. These data can then be used to inform an ongoing sampling program of water and surface sediment, allowing comparison to previous conditions and to track the influence of climate change and potential impacts of future mining projects.


Sediment cores have been collected during the MWSP annual field sampling trips in 2015, 2016, and 2017, an on-the-land sampling trip which involves many from the community including trained Tłı̨chǫ environmental monitors and elders. The belief held by the Tłı̨chǫ community is that scientific data and methods are an asset to the monitoring program complementing their extensive Tłı̨chǫ knowledge of the Marian Watershed. This provides an incredible learning opportunity for accompanying scientists and community members.

Since 2015, sediment cores as well as surface sediment and water samples have been collected by James Telford with the support of Tłı̨chǫ environmental monitors during these community-led sampling trips. Sample site selection of sediment cores, water and surface sediment is done in consultation with Tłı̨chǫ Elders regarding culturally important areas such as traditional fishing locations as well as physical changes in landscape characteristics best suited to monitoring.

These results will contribute directly to the MWSP, providing a strong foundation of scientific data to inform continued monitoring. During these field trips, James has trained environmental monitors in techniques in multiple field methods including obtaining sediment cores and surface sediment samples, collecting water for chemical analysis, GPS operation, and sample site selection. Results have been shared at two Tłı̨chǫ Results Workshops in March 2016 and 2017, with a third scheduled for March 2018. Results have also been shared at the Cumulative Impact Monitoring Program 2017 Community Results Workshop.