Great Lakes primary productivity (IMAGE) Michigan Technological University Caption Image Caption: The map shows the mean production for the year 2008 across the Laurentian Great Lakes region. Lake production values are scaled from low (blue) to high (red). Image Description: A satellite image of the Great Lakes with different colors across the lakes to show lake production values. Credit Karl Bosse/MTRI Usage Restrictions Please credit photo 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.