Brain Coral Bleaching (IMAGE) US Geological Survey Caption No, that is not a mound of snow sitting on a coral reef -- it is a colony of bleached "brain coral" on a reef off of Islamorada, Florida. Hard and soft corals are presently bleaching- losing their symbiotic algae -- all over the coral reefs of the Florida Keys due to unusually warm ocean temperatures this summer. Months with waters warmer than 85 F have become more frequent in the last several decades compared to a century ago, stressing and in some cases killing corals when temperatures remain high for too long. Credit Kelsey Roberts, USGS Usage Restrictions Open use with photo 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.