NWT RESEARCH DATABASE

Tags: contaminants, mercury, fish, metals, fish health, 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 a batch of spring-caught fish and a batch of summer/fall-caught fish for this study. Twenty whole lake trout and 20 whole cisco of a range of sizes are required from each collection period. 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 the principal investigator are removed 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 for the research team. The 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 will be kept informed of the progress of the study through reports and possible community visits. The fieldwork for this study will be conducted from July 4, 2013 to December 31, 2013.