Long-term monitoring of trace metals and persistent organic pollutants in lake trout from Kusawa Lake and Lake Laberge, Yukon

• Main Authors: Gamberg, Mary, Stern, Gary, Barker, Oliver, Fulmer, Deb, Krieger, Monica, MacDonald, James, Muir, Derek, Otto, Darell, Sembsmoen, Dave, Wang, Xiaowa
• Format: Dataset
• Language: unknown
• Published: Canadian Cryospheric Information Network 2019
• Subjects: Yukon; Champagne; Dun; Aishihik; Lake Laberge; Kusawa Lake; First Nations; Whitehorse
• Online Access: https://dx.doi.org/10.21963/11703; https://www.polardata.ca/pdcsearch/?doi_id=11703

This project has been monitoring contaminants in lake trout from Lake Laberge and Kusawa Lake in the Yukon, since 1993, and annually since 2001. In the fall of 2018 and early winter of 2019, 15 lake trout were collected from Kusawa Lake and 21 from Lake Laberge. Otoliths were aged and liver and muscle samples from these fish are currently being analyzed for a suite of elements, new contaminants (fluorinated and brominated compounds) and older organochlorine pesticides. Previous data from this project are being gathered and curated prior to being analyzed and reported. Mercury levels in muscle from lake trout from Lake Laberge and Kusawa Lake averaged 0.25 and 0.24 g·g-1 respectively, about half the recommended guideline level of 0.50 g·g-1 for commercial sale. Mercury is declining over time in lake trout from both lakes although there is considerable annual variation. Arsenic concentrations in lake trout muscle decreased over time in Lake Laberge but not in Kusawa Lake, while selenium increased over time in Kusawa Lake but not in Lake Laberge. Both changes were small and likely of little biological significance. Outreach programs were conducted with the Yukon Fisheries Field Assistant Program and the Yukon Fisheries Management Program at Yukon College in Whitehorse, YT. The first group was able to use the recently acquired Direct Mercury Analyzer to measure mercury in their fish. Ta’an Kwach’an Council and Champagne and Aishihik First Nations are integrally involved in fish collections for this project and in the ongoing refinement of the communication of results. We have been developing our communication capacity, and are including Yukon Contaminants Committee, Yukon Environment (Fisheries) and Kwanlin Dun First Nation in discussions. As we move forward with this collaborative approach we anticipate many new opportunities for value-added consultation and communication activities.