Record high ocean temperatures in the western Pacific have caused more than half of the Great Barrier Reef to undergo a mass coral bleaching event this year, according to a team of Australian scientists conducting aerial surveys.
Corals thrive in a narrow temperature range, and when waters warm above normal—as they have this year from climate change and a strong El Nino—the organisms expel their symbiotic algae, leaving them without a source of food and susceptible to disease. Scientists’ next step is studying the corals up close to determine how deep the bleaching is, said Terry Hughes, a marine biologist at James Cook University and head of the Australian coral bleaching task force. “If the corals are severely bleached, then a lot will die,” Hughes said. “If they are lightly bleached, which is the case with a lot of reefs south of Townsville, then they’ll regain their color over the next couple of months and there won’t be much mortality.”
ARC Coral Reef Studies