NWT RESEARCH DATABASE

Tags: contaminants, mercury, fish, metals, cisco, isotopes, lake trout, tissue sampling

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

Project Description: This study is designed to find out whether contaminant levels are changing in fish (lake trout and cisco) in Great Bear Lake. The research team require fall-caught fish for this study. 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 Environment Canada-Saskatoon. The fish will then be forwarded to Environment Canada-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. The 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 Renewable Resource Council (RRC) to have community members collect the fish. The research team 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. Community members (chosen by the local RRC) will be selected to collect fish for this study. The community will be kept informed of the progress of the study. Results will be presented through reports and possible community visits. The fieldwork for this study will be conducted from December 4, 2014 to December 31, 2014.