NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: greenhouse gases, carbon dioxide, methane, river emissions

Objective(s): To transform understanding of how greenhouse gas emissions from rivers will impact the future trajectory of atmospheric CO2 and CH4 concentrations by conducting river-borne measurements of surface water CO2 and CH4 release and trace elements from soils, sediments and rocks in the Peel, Arctic Red and Mackenzie rivers.

Project Description: This licence has been issued for the scientific research application No. 5924. The ultimate aim of this research is to transform understanding of how greenhouse gas emissions from rivers will impact the future trajectory of atmospheric CO2 and CH4 concentrations. Two key research objectives have been identified to address major research gaps in this carbon flux: Objective 1: Conduct river-borne measurements of surface water CO2 and CH4 release (and age and source) at a high spatial and temporal resolution to create a time series and footprint of greenhouse gas release from the Mackenzie river. Objective 2: Establish the release of trace elements from soils, sediments and rocks in the Peel, Arctic Red and Mackenzie rivers. The methods used are tied to the objectives of the project and summarised here: Objective 1: Sample river surface CO2 and CH4 concentrations will be sampled using high-frequency gas sensors, which will be custom fitted onto the locally hired boat(s). Alongside, river water will also be collected in vials, sampled using a 60 ml syringe and mixed with ambient air by vigorous shaking for 1 min. The head-space will then be injected under overpressure into pre-evacuated exetainers which will be transported to the UK for storage. These samples will be analyzed at the University of Bristol using a GC-iRMS and University of Glasgow using an AMS for isotopic composition of CH4 and CO2 respectively. Objective 2: Soil and sedimentary pore waters in the Mackenzie Delta region will be sampled. Samples will be collected using Rhizon filters at multiple depths in sedimentary exposures. Filtered water will be stored in acid pre-cleaned HDPE bottles and shipped to the UK for storage. In Oxford, the geochemistry of these samples will be analysed by ICPC-MS to quantify concentrations of trace metals. Upon visiting local communities, time will be taken to explain the approach and methods and answer any questions people may have. Communities will be revisited to explain findings as the project moves forward. Summaries in non-technical language will be provided to explain the main findings. As part of this 5 year project funded by the ERC (5 years) and Leverhulme (2 year), there is the possibility of collaborative research between those in the community, as well as opportunities for additional employment associated with sample collection. While visiting the field, the research team will also look to hire local boats and boat drivers to help with research plans and help advise us on sampling locations. Wildlife monitors and accommodation in communities may also be needed. The fieldwork for this study will be conducted from: June 01 - August 10, 2024