NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area, Dehcho Region, North Slave Region

Tags: physical sciences, water quality, permafrost, climate change, methane

Objective(s): To identify impacts of climate change and permafrost thaw on pond methane emissions, and on water chemistry in streams that drain peatland-rich catchments.

Project Description: This licence has been issued for the scientific research application No.4734. The objective of this research is to identify impacts of climate change and permafrost thaw on pond methane emissions, and on water chemistry in streams that drain peatland-rich catchments. Impacts on methane emissions will be assessed. Specific objectives are: 1) to characterize the trends and variability in magnitude of methane emission from ponds along climate gradients within both the Taiga Plains and Shield regions of the Northwest Territories (including further sites in Alberta and Saskatchewan); 2) to investigate the influence of permafrost thaw on methane emissions from peatland ponds on the Taiga Plains; and, 3) to understand the impacts of permafrost thaw on water quantity and quality in streams draining peatland-rich catchments. The research team will measure methane emissions from ponds in various regions and latitudes across the NWT and also include sites in Alberta and Saskatchewan. This research will be done over the span of three summers. First, the team will measure emissions from 5 to 10 lakes at each of the four NT locations, near Fort McPherson, Tuktoyaktuk, Yellowknife, and Wrigley. This will be done between 1 and 4 times per season, depending on site and year. The team will use a state of the art, portable gas analyzer (LGR, USA) to measure methane emissions. This is a non-invasive approach, during which floating chambers are used to capture methane gas coming from the surface of the water. The team will reach the centers of the lakes using inflatable kayaks. General water characteristics, including temperature, pH, conductivity, and dissolved oxygen will be measured using a handheld sensor. Water samples will be collected from the ponds for further analyses. In order to better predict what pond characteristics best explain variability in methane emissions across the Northwest Territories, the research team will characterize ponds with regards to sediment type (peat or mineral) and sediment thickness, dominant surrounding ecosystem types, pond size and shape, and water chemistry. This will allow the team to identify the primary controls on methane emissions across a large climate gradient and across regions with very variable surface geology. For the second component the research team will establish continuous monitoring of discharge and water quality at Smith Creek (near Wrigley) and Scotty Creek (near Jean Marie River) outflows, and at a sub-catchment outflow within Smith Creek catchment. The monitoring at Scotty Creek is a continuation of a previous research project, while the research at Smith Creek is dependent a funding request currently in review. Continuous stream measurements will include stream stage, using pressure transducers, electrical conductivity, temperature, and absorbance across the full UV-vis spectra. The UV-vis spectra will yield information on turbidity, and on the quantity and chemical composition of dissolved organic matter (DOM). This instrumentation has recently been used at Scotty Creek, and monitoring at Smith Creek will thus yield comparable data. Manual grab samples will be taken at least bi-weekly from late May to late October. Manual water samples will be analyzed for pH, turbidity, dissolved oxygen, major ions, total organic carbon and total nitrogen, and DOM analysis of optical properties through UV-vis absorbance and fluorescence. The team will at the Smith Creek site collect permafrost peat cores for soil analysis, which will allow the team to understand the potential role of permafrost thaw for catchment delivery of solutes. The monitoring program will allow the team to understand controls of contributions from different catchment water sources, and their influence on solute export and water quality. The community of Wrigley is in close proximity to the primary field sites. The plan is to; 1) engage students at the K-9 Chief Julian Yendo School with an interactive day of science; and, 2) report scientific results to community members at the Pehdzeh Ki Band Office. The research team plans to present an outline of the hydrology field work in the classroom and introduce the use of water sampling equipment. The presentation would be followed by an excursion to the field sites including Smith Creek (60 m from highway) and a peatland complex (200 m from highway) where she would discuss vegetation and hydrology with the students and demonstrate field hydrology techniques. The field excursion would be accompanied by teachers and other supervisors. The research team plans to contact an Elder who has previously assisted the team as a wildlife monitor to provide a prospective on the land. Afterwards, the research team would debrief with the students to discuss their involvement in the community meeting. The research group presented preliminary research findings to a small group of band office employees and community members in August of 2019, and hope to increase engagement. Ideally, elementary school students would attend and demonstrate field techniques they learned. The research team also plan on returning to Fort McPherson to present results to the community within the school. The fieldwork for this study will be conducted from Aug 20, 2021 to December 31, 2021.