More is available here. From the press release:
Once the most abundant and important reef-building corals in Florida and the Caribbean, staghorn and elkhorn corals have declined by upwards of 90 percent in many areas, primarily as a result of disease and “bleaching,” an often-fatal stress response to abnormally high water temperatures in which corals expel the symbiotic algae that give them color. The rising temperature of the ocean as a result of global warming is the single greatest threat to these two coral species as well as coral reefs more generally worldwide. Scientists have predicted that most of the world’s coral reefs will disappear by mid-century due to global warming and the related threat of ocean acidification under a business-as-usual emissions scenario.