NWT RESEARCH DATABASE

Regions: North Slave Region, South Slave Region

Tags: mercury, fish, organic contaminants, Great Slave Lake

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. 6000. The 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 team have been studying since the early 1990s. The plan is 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. We plan to collect: - 20 burbot and 20 northern pike will be collected from the Fort Resolution area of Great Slave by the community. - 20 lake trout will be collected from the Hay River area of Great Slave Lake by a commercial fisherman. - 20 lake trout and 20 burbot will be collected from the Lutsel K’e area of Great Slave Lake by the community. The team maintains regular contact with community members by telephone and email from 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. The team also have 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 our studies under NCP and related and ideally to give presentations in the schools. The team also want to discuss interests in new studies on Great Slave Lake including the mooorings. The fieldwork for this study will be conducted from: October 01 - December 31, 2024