NWT RESEARCH DATABASE

Regions: Qikiqtaaluk Region

Tags: contaminants, mercury, cisco, lake trout

Objective(s): To determine whether contaminant levels are changing in fish (lake trout and cisco) in Great Bear Lake.

Project Description: This licence has been issued for the scientific research application No.5046. This study is designed to find out whether contaminant levels are changing in fish (lake trout and cisco) in Great Bear Lake. Of particular interest is mercury. It complements ongoing fish population studies being conducted by the Department of Fisheries and Oceans on Great Bear Lake and contributes to Deline's research and monitoring plan objectives. Twenty whole lake trout and 20 whole cisco of a range of sizes are required from Great Bear Lake. The fish will be frozen immediately after capture and shipped to ECCC-Saskatoon. The fish will then be forwarded to ECCC-Burlington for processing. Fish length, weight, age, and gender are determined. A subsample of fillet for fish from the lakes investigated by Evans’ is removed and shipped to her for mercury and potentially other analyses of fillet. Remaining carcasses are homogenized and chemical analyses (PBDEs, metals, including mercury) and carbon and nitrogen isotopes performed on the whole body. Correction factors have been developed for mercury measurements in whole body versus fillet. Arrangements will be made by the local RRC to have community members collect the fish for us. We expect the community members will provide the fish from their normal subsistence catch. Coolers will be shipped to the RRC for return shipment of the frozen fish. Through reports, posters and community visits. Some of our findings are presented by Fisheries and Oceans as part of their meetings. The fieldwork for this study will be conducted from September 4, 2021 to December 31, 2021.