
"The most exciting thing was discovering live, healthy corals on reefs already as hot as the ocean is likely to get 100 years from now," says Stephen Palumbi of Stanford University.
Corals have a symbiotic relationship with tiny algae called zooxanthellae. The corals give the algae a home and, in exchange, the algae provide the corals with food. When water temperatures get too hot, the corals expel the algae. This is what is known as coral bleaching and it is expected to kill coral reefs around the world as global temperatures rise.