NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: physical sciences, water quality, permafrost, organic carbon

Objective(s): To better understand how water quality will be influenced by a warming climate, with specific attention to dissolved organic carbon.

Project Description: This research focusses upon dissolved organic carbon (DOC) quantity and quality from a suite of hydrological environments underlain by discontinuous permafrost. The research looks to better understand how water quality will be influenced by a warming climate, with specific attention to DOC, by analysing historical water quality data (30 years) from three local rivers (Yellowknife, Cameron, and Marian rivers) and by examining DOC water quality data from different environments in the NWT. This year, aside from these rivers (where data has been gathered by Environment and Natural Resources and other territorial and federal government departments over the past many years) streams and lakes in the Wekweeti region will be samples to define the range and background chemistry and possibly what differentiates carbon chemistry from different types of catchments draining into streams and lakes. The research team are interested in how these values change seasonally. Field Component Water will be sampled from subsurface waters and surface waters. Subsurface waters are collected from piezometers (pipe in ground to collect water) already installed in two peat plateaux around Yellowknife (Site 1: near Airport; Site 2: Pontoon Lake) and Wekweeti area. Water is taken from approximately 10 to 50cm below surface, depending on the active-layer thickness. In areas where piezometers may not exist, the research team bring (and later remove) small metal rods (approximately 50-75mm diameter; 50-75cm long) to insert at different depths within the peat. Here a small pump and tubing will be used from the piezometers to obtain the water samples, which are brought back to the accommodations for further filtering. Surface waters will be collected from nearby ponds, Slave Lake, Pontoon Lake, Yellowknife River, Cameron River, Marian River, and Baker Creek. In addition, there is the possibility for opportunistic sampling of creeks, ponds, and rivers along the highway (i.e.: Stagg River), allowing the team to increase the spatial dataset. Surface waters are collected by hand and require no additional equipment. Most samples are filtered in-field to 0.45um, except for large volume samples (>10L) which are sampled into large containers and filtered back at the base camp. Samples are transported into and out of the field using a regular cooler containing ice-packs. All equipment and trash that is brought into the field is also taken out, leaving nothing in the field (except for pre-existing piezometers or weather stations). Laboratory Component All experimental and geochemical analyses is conducted back at the University of Waterloo. Samples are run for concentrations of DOC, major ions, iron, and nitrogen. DOC characterization techniques include light absorbance, molecular size determinations, and how easily and quickly DOC degrades by sun and microbes. The research team will also be submitting these water samples for isotopes in order to better understand the age and source of DOC and water. The plan is to visit Wekweeti in October to sample streams and lakes for surface water chemistry, particularly carbon and nitrogen. The research team will engage members of the community in terms of meeting, sampling and having discussions about water quality. The Principal Investigator has been working out of Wekweeti for several years on a variety of projects. The research team also work with the local school (Arrowmaker) and are planning on speaking with the students about a potential project. The research team presented the results of the last study on caribou and snow structure to the village of Wekweeti at a community dinner which the research team had presented with Wekheezhi Land and Water board. The research team also have experience in Wekweeti presenting the research to school children and teachers as well as to meetings of hunters and trappers (small and larger groups). During the study the research team will continue to meet with individuals and groups of interested residents of Wekweeti. The team also plan on doing a project with the school. The fieldwork for this study will be conducted from October 3, 2015 to November 8, 2015.