NWT RESEARCH DATABASE

Regions: Sahtu Settlement Area

Tags: climate change, cumulative effects, wildfire, permafrost thaw, Ts'ude Niline Tu'eyeta, aquatic ecosystems health

Objective(s): To evaluate responses of aquatic ecosystems to permafrost thaw, lake drying, and wildfire, as well as their cumulative impacts.

Project Description: This licence has been issued for the scientific research application No. 5930. This project proposes to evaluate responses of aquatic ecosystems to permafrost thaw, lake drying, and wildfire, as well as their cumulative impacts. Lake chemistry and biological diversity (microbes and invertebrates) in water (current environmental change) and in sediments (historical change) will be characterized, focusing on a set of lakes that vary in expected degree of change. The four objectives to be addressed through a combination of short-term, directed research studies and longer term monitoring efforts are: 1- Characterize changes in water chemistry (including metals and contaminants) and biological diversity (bacteria and invertebrates) over a wide range of aquatic ecosystems in the vicinity of Fort Good Hope (FGH) and Ts'ude Niline Tuyeta, 2- Characterize changes in these ecosystem measures over longer time periods by investigating lake sediments, 3- Compare patterns in water chemistry and aquatic diversity to other locations in the NWT to consider implications at a broader spatial scale, and 4- Evaluate influences of stressors on surface water quantity and quality to assess the vulnerability of lakes to serve as drinking water source. Wetlands are commonly seen as sentinels of changes occurring in the surrounding landscape. Whereas some of these ecosystems in the area have already been impacted by a wide range of human activities, including development of oil and gas and associated infrastructure, others such as Ts'ude Niline Tu'eyeta have been protected from anthropogenic disturbance. Similarly, the region lies in continuous permafrost, with some aquatic ecosystems being impacted by thawing permafrost. The latter will be investigated by researchers from the Geological Survey who characterized different lakes and wetlands based on distinct geomorphological processes. For both areas, surface water will be sampled and analyzed for water chemistry (e.g. DOM, nutrients and metals) at Taiga laboratories in Yellowknife, bacteria and invertebrates’ diversity across both gradients. Invertebrates identification will be performed by students from FGH school as initiated and supervised by Gurney in past studies. Diversity of bacteria will be performed at INRS. What remains unknown is if these waterbodies have experienced comparable perturbation in the past. To this end, sediment cores will be collected at each sites. The structure of the cores will be analyzed at INRS and the bacterial diversity will also be analysed at INRS. Environmental stressors can affect surface waters used as drinking water source for the community. Variability of source water quality can affect water treatment ability to meet territorial requirements in term of drinking water quality. Therefore, a vulnerability analysis will be conducted by Dr. Guilherme around water sources. This analysis will identify threats, such as activities or natural or anthropogenic events that can affect the quality or quantity of source water and potentially drinking water. These threats can be sources of water contamination or potential hazardous events impacting source integrity. Permafrost data will be collected and analyzed by Northwest Territories Geological Survey. An update on year 1 research has been shared and discussed with the K’asho Gotine Foundation president (Mr. Daniel Masuzumi) and his team, the president of Fort Good Hope Renewable Resource Council team in January 2024. During this visit logistics for 2024 sampling has also been discussed. The collaboration and support from the community members and agencies of Fort Good Hope is critical for this project. The community’s partnership will be acknowledged in all communications (e.g. an abstract has been accepted for an oral presentation to the international ASLO meeting in June 2024 in the US). Phase I of the project has been published in the NERB series of GNWT (https://www.gov.nt.ca/ecc/en/services/nwt-cumulative-impact-monitoring-program-nwt-cimp/nwt-environmental-research-bulletin) Results are shared with the communities through meetings and plain language reports and data are made available through the Mackenzie DataStream. The fieldwork for this study will be conducted from: June 8 - July 02, 2024