    Simon Donner  The long-term survival of coral reefs will
depend on how well they can deal with rising ocean temperatures.
Corals, the animals that famously build reefs, get most of their
energy and color from microscopic algae that live inside their
tissue. This unique arrangement is very sensitive to the
surroundings, however. When the water gets too warm, the corals
expel or consume the algae, and turn white. If the warm water
persists, this "bleaching" process can starve corals to death.
In May I traveled from my lab at the University of British
Columbia to the Gilbert Islands, part of the island nation of
Kiribati, in the central equatorial Pacific. They offer a unique
natural laboratory for studying how coral reefs respond to
frequent ocean heat waves. When an El Niño climate event sets up
in the Pacific, the ocean around Kiribati—in the heart of the El
Niño zone—warms up. By studying changes in the coral community
after El Niño events, we can evaluate what types of corals and
reef habitats are most