Corals, Chemistry, and Climate

Some corals grow in layers like trees, providing a record of past temperatures at the sea surface. However, the interpretation of the data is not always easy. In their Perspective, Schrag and Linsley discuss Cohen et al.9s study of the effect of symbiotic organisms on the most widely used measure of paleotemperature in corals. They caution, however, that the results may not apply to tropical corals.