Ocean surface temperatures off the Florida Keys rocketed to a record high of over 90 degrees Fahrenheit on Monday, causing alarm about a possibly unprecedented threat to coral reefs. The daily average surface temperature climbed just over 90F on Monday, according to the National Oceanic and Atmospheric Administration (NOAA), despite coral reefs usually enduring the most heat stress in the months of August and September. The reefs, which play a vital role for many marine ecosystems and protect coastlines, can bleach when temperatures become too high, which can in turn cause coral to die. Bleaching has not yet been reported in Florida but it has already started in reefs in Central America. “We’re entering uncharted territories,” NOAA ecologist Derek Manzello told The New York Times.