Enhanced investigations of the factors affecting long-term contaminant trends in predatory fish in Great Slave Lake, Northwest Territories

This study addressed the issue of obtaining a broader understanding of the factors affecting contaminant time trends in Great Slave Lake burbot and lake trout and mercury trends in smaller lakes to the west through sediment coring studies and additional fish sampling. In 2008/2009 we conducted sediment coring in three regions of the lake and in the general areas where fish are being monitored for contaminant trends and resumed burbot monitoring for mercury at Lutsel K'e. In 2009/2010 cores were dated and analyzed for mercury and productivity trends; pike monitoring resumed at Fort Resolution. In 2010/2011 we continued our expanded mercury monitoring on Great Slave Lake and assessed time trends. Time trends also were investigated in smaller lakes to the west.