Shells comparison (IMAGE) University of Plymouth Caption A comparison of shells assessed during the research, with the top shell taken from waters with present-day CO2 levels and the bottom one from waters with future predicted levels Credit Ben Harvey/University of Tsukuba 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.