NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: climate change, carbon, freshwater biodiversity, environmental DNA

Objective(s): 1) Assess the spatial and temporal distribution of particulate and dissolved nutrients/carbon along a large- and small-scale latitudinal gradients in the MRB; 2) Determine particulate and dissolved carbon flux through long-term hydrological monitoring and simulations/experimentation (Rain simulations; river simulations in lab); and, 3) Correlate biodiversity shifts in lower trophic levels such as prokaryotic and eukaryotic microbial communities, and up to macroinvertebrate communities with observed physico-chemical, landcover, nutrient and permafrost thaw gradients; We will investigate reciprocal flows of energy subsidies.

Project Description: This licence has been issued for the scientific research application No. 5507. The objectives of this research are to: 1) Assess the spatial and temporal distribution of particulate and dissolved nutrients/carbon along a large- and small-scale latitudinal gradients in the MRB (I.e. Slave River, Great Slave Lake, Mackenzie River, Laird River, Peel River, smaller headwater streams); Correlate “in-stream/in-lake” measurements with remote sensing surveys (Caren remote sensing – next year can spend more time potentially?) 2) Determine particulate and dissolved carbon flux through long-term hydrological monitoring and simulations/experimentation (Rain simulations; river simulations in lab) 3) Correlate biodiversity shifts in lower trophic levels such as prokaryotic and eukaryotic microbial communities, and up to macroinvertebrate communities with observed physico-chemical, landcover, nutrient and permafrost thaw gradients; We will investigate reciprocal flows of energy subsidies (I.e., invertebrate prey) linking streams with riparian areas to understand trophic linkages between changing Arctic landscapes and freshwaters. This research will seek to build on existing knowledge and collaborative, multi-disciplinary expertise to combine in-situ data, with novel large-scale laboratory simulations to determine the fate of sediment associated carbon, providing much needed process-based research integral to model development and produce an understanding of the microbial/biotic interplay with these processes. FIELD WORK: Sample collection will take place at several locations along tributaries of the Mackenzie River (kmz file attached). In the 2023 field season, work will be principally focused on road-access locations, and scouting for potential in-land locations requiring helicopter access for upcoming years. We have included potential inland sites in the proposal locations as they will important for scientific license renewal in 24/25. Field work will include both water, sediment collection, and macroinvertebrate sampling at each location, as well as on-site water quality measurements using water quality instrumentation (e.g., EXO water quality sonde, RS5 Acoustic Doppler). At many of the streams, we will also incubate decomposition assays (e.g., standardized cotton strips, locally gathered leaf material in mesh packs) and chlA samplers (e.g., glass fritters). SEDIMENT COLLECTIONS: Bulk and sediment sample collection will take place at 4-6 road-side sites, and will be collected using clean buckets and stainless steel shovels to fill 2 x 20L prepared sample containers. Riverbed sediments will be collected at every site, using stainless steel shovels, Ponar type sampler or gravity corer to fill 5-10 10ml sample vials at each site. These samples will be frozen, and shipped in specialized shipping containers to HEMReF facility in Burlington Ontario. All sediment samples will be shipped to the Hydroecology Monitoring and Research Facility (HMReF) located at ECCC, Burlington, for laboratory analysis and experiments. MACROINVERTEBRATE, BIOFILM AND ORGANIC MATTER SAMPLING: Canadian Aquatic Biomonitoring Network (CABIN) protocols to measure a suite of habitat measures (e.g., channel bed sinuosity) and macroinvertebrate indicators (e.g. Richness and diversity) Examination of ecosystem function through measurement of instream organic matter processing (i.e., decomposition assays) incubated for roughly 4-8 weeks at each site before retrieval. Emerging insects will be collected at road access sites using a short duration mesh net set up at the water surface, and allochthonous insect input into streams will be collected using short duration pitfall set ups checked at 24-48 hour intervals. At each site, 5 fist sized rocks will be collected and brushed for sampling biofilm community structure. WATER QUALITY SAMPLING: River water quality samples will be collected using standard HDPE sampling bottles and 20 L pails/buckets. About 20-30L of water will be collected from each sampling site. The water grab samples will be shipped to ECCC laboratories in Burlington and Saskatoon for water quality analysis. Detailed water quality profiles will be collected at each site using water quality instrumentation (YSI6600V2 or EXO2 water quality sonde on a cable). Conductivity, temperature, and water level loggers (Hobo) will be incubated in streams throughout the study season. Laboratory work: At the Hydroecology Monitoring and Research Facility (HMReF) in Burlington, studies will be conducted in the 2m annular flume to simulate sediment transport dynamics (erosion, transport, deposition). The flume is instrumented for real-time measurement of geochemical processes during transport. Water Chemistry samples will be processed for nutrients at the National Laboratory for Environmental testing in Burlington. (DIC/DOC/TOC/TIC) Bacterial sequencing from water and sediments at the NHRC in Saskatoon To communicate results to individuals and communities in the North, the researchers will hold community-based meetings and consultations in northern communities to inform residents in the region of the nature and significance of the research, what we are trying to find out and why, and provide updates on our progress. Information can also be made available though brochures, posters, videos, fact sheets, journal publications, etc. Through consultations with HTCs and the Inuvialuit Game Council in the Inuvialuit Settlement Region and RRCs in the Gwich’in Settlement Area, community members and community organizations, we will share our respective environmental knowledge – local traditional environmental knowledge gained will contribute to our planning of field activities. In addition, we will plan to present research and findings through the community seminar series at the Aurora Research Institute. The fieldwork for this study will be conducted from: July 01 - October 31, 2023