The Florida Keys reef tract (IMAGE) University of Southern California Caption The Florida Keys reef tract, pictured here, has not experienced temperatures this extreme in at least 40 years. (Photo/iStock.) Credit iStock Usage Restrictions More information here: https://www.istockphoto.com/legal/license-agreement 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.