NWT RESEARCH DATABASE

Regions: Sahtu Settlement Area, Dehcho Region, South Slave Region

Tags: contaminants, water quality, fish health, metal contamination

Objective(s): To investigate whether contaminant (mercury, other metals, persistent organic contaminants) levels are changing in fish in the Northwest Territories with a focus on Great Slave Lake, which the research team has been studying since the early 1990s

Project Description: This licence has been issued for the scientific research application No. 5669. This research study is continuing to investigate whether contaminant (mercury, other metals, persistent organic contaminants) levels are changing in fish in the Northwest Territories with a focus on Great Slave Lake, which the research team has been studying since the early 1990s. The team plans to arrange collections of lake trout from the Hay River area and Lutsel K’e areas; burbot from the Lutsel K’e and Fort Resolution areas; and northern pike from the Fort Resolution area of Great Slave Lake. All Great Slave Lake fish will be collected by community members. Collected fish will be frozen and then shipped to Environment and Climate Change Canada-Saskatoon, where they will be processed and sampled. Any abnormalities (internal or external) will be noted. Muscle, liver, stomach, and otolith samples will be collected from each fish. Otoliths will be sent to a private contractor for the determination of fish age. Tissue samples will be submitted to Environment and Climate Change Canada laboratories in Saskatoon and Burlington for stable isotope (muscle) and contaminant analyses (metals in lake trout and burbot muscle; organic contaminants in lake trout muscle and burbot liver). These data are proving to be very valuable in investigating why contaminant levels are or are not changing in fish over time. The research team plans to collect: 1) 20 burbot and 20 northern pike will be collected from the Fort Resolution area of Great Slave by the community; 2) 20 lake trout will be collected from the Hay River area of Great Slave Lake by a commercial fisherman; 3) 20 lake trout and 20 burbot will be collected from the Lutsel K’e area of Great Slave Lake by the community. The research team maintains regular contact with community members by telephone and email from the Northern Contaminants Program (NCP) proposal submission, NCP report submission, obtaining fish for analyses, and discussing results. Copies of the proposal and annual report are provided to the community organizations. They have also developed simple posters of the mercury results which have been well received. Zoom meetings have become more frequent in support of this and related studies. A fall visit is planned to discuss results to date of the research team’s studies under NCP and related and ideally to give a presentation in the schools. The team also wants to discuss interests in new studies on Great Slave Lake. The fieldwork for this study will be conducted from: August 01 - December 31, 2023