NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, water chemistry, permafrost thaw, stream health

Objective(s): To understand how permafrost slumping increases the mobilization of carbon, nutrients, and toxins (mercury) from land to water, and the effects of this transport on stream ecosystems and the global carbon cycle.

Project Description: This licence has been issued for the scientific research application No. 5597. The objective of this research is to understand how permafrost slumping increases the mobilization of carbon, nutrients, and toxins (mercury) from land to water, and the effects of this transport on stream ecosystems and the global carbon cycle. Over the next several years, the research team plan to measure stream chemistry at a series of sites that drain from the Peel Plateau, near where they enter the Mackenzie Delta. The team will compare the stream chemistry from these sites to sites that drain into the Mackenzie Delta from east of Inuvik to understand how different types, and amounts, of permafrost thaw within a watershed affect stream chemistry. The team will also work at slump sites in the Stony Creek, Vittrekwa River, and Willow River watersheds, to measure the composition of materials released from slumps, and document how it travels downstream. To understand the effects of slumping on stream organisms, the research team will collect benthic invertebrates and bacteria upstream and downstream of slump sites. To understand how the composition of material that is lost from slumps has changed over time, the team will also collect sediments from Willow Lake, which has filled up as a result of thaw slump activity in the Willow River. As described elsewhere in this application, all hike-in work on the Peel Plateau will be conducted with the assistance of wildlife monitors, arranged as appropriate via the Tetlit (Fort McPherson) and Ehdiitat (Aklavik) RRC, and as long as COVID considerations do not prohibit this interaction. For helicopter, roadside, and slump sites, the team will collect simple streamwater samples using 1 - 2 litre bottles that will be submerged just below the water surface and filled. At slump sites, the team will collect samples immediately upstream and downstream of where the slump enters the stream. Elsewhere, the team will take a single sample from the stream bank. Water samples will typically be filtered at the Aurora Research Institute lab facilities in Inuvik, using a simple vacuum pump. Further analyses will be conducted at the University of Alberta. When invertebrate samples are collected, the team will use passive samplers that are left in the stream for 2-3 days, or use a “kick net” on the stream bed over a constrained (<10 m2) area. To collect sediment cores from Willow Lake, the research team will travel during the early spring (April), and collect cores through the lake ice to minimize disturbance. Cores will be immediately deposited into bags, and kept frozen for transport back to the University of Alberta. The research team may also collect streambank sediment samples at this time. In 2021, all of our work will follow COVID protocols which must be approved by the University of Alberta (masking, physical distancing, only same-cohort individuals travelling together in trucks). Given the participation of GNWT scientists as collaborators on this research, we also have access to, and will adapt for our purposes, GNWT COVID protocols for our work. As in past years, the research team are happy to give presentations to local community organizations that are interested in our work. Presentations to schools are difficult, however, because the team usually don't arrive in Inuvik / Fort McPherson until mid-June! In past years, Suzanne Tank (project principal investigator) has given presentations to the Tetlit (Fort McPherson) RRC, and Tank and graduate students have given presentations as part of the Aurora Research Institute speaker series. This year, the research team will also prepare research summaries, and will circulate these to RRCs and any other interested parties. The team also find that having community members involved in our research on a day-to-day basis as wildlife monitors is very helpful for allowing us to incorporate community feedback into our efforts, and for facilitating the passing on of information about the research we are conducting to other members of the community. The research team are always more than happy to hear suggestions about how to improve the communication efforts! The fieldwork for this study will be conducted from July 3, 2023 to August 31, 2023.