Fire corals resemble typical stony corals but are actually close relatives of jellyfish; hence their wicked sting. They have the ability to grow either as sheets—expanding as a flat coating across rocks and other surfaces—or as “trees,” sprouting upward with a stem and branches. More than 40 years ago, Jeremy Jackson, an ocean biologist with the American Museum of Natural History and the Smithsonian Tropical Research Institute, proposed that this plasticity would give fire corals an edge as Caribbean reefs experienced global warming and hurricanes. Edmunds now concludes Jackson was right.
Coral bleaching occurs when corals are stressed by changes in environmental conditions, such as increased water temperatures. This stress causes the corals to expel the algae living in their tissues, turning them white or pale. Without the algae, the corals lose their main source of food and become more susceptible to disease and death.
