Oysters (IMAGE) University of Washington Caption More acidic seawater is corrosive and contains less of the minerals that oysters need to build their shells. Credit Marc Dewey / Taylor Shellfish Usage Restrictions With credit 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.