Chinook Salmon (IMAGE) U.S. Geological Survey Caption Managers have reduced Lake Michigan stocking levels of Chinook salmon at least three times over the past decades in response to declining prey fish and the natural reproduction of Chinook salmon. Credit Michael Humling, U.S. Fish and Wildlife Service. Public domain. Usage Restrictions None 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.