Lake Productivity Trends (IMAGE) Michigan Technological University Caption Caption: Annual lakewide production over the 16-year study period (2003-2018) for Lake Tanganyika, Great Bear Lake and Great Slave Lake. Each of these lakes exhibited significant changes in production over this time period, with the best fit line plotted over the annual data. Description: A line plot with three lines showing lake production trends for Lake Tanganyika (the line is trending down), Great Slave Lake (the line is trending up) and Great Bear Lake (the line is trending up). Credit Karl Bosse/MTRI Usage Restrictions Please credit properly. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.