The whimsical names of corals—bubble, staghorn, starburst and brain—hint at their spectacular appearance, but not necessarily at their true value. As the largest living structures on the planet, coral reefs are also among the greatest storehouses of biodiversity on Earth.
Coral reefs are also one of the most threatened marine systems. Scientists estimate that unless we take immediate action, we could lose up to 70 percent of coral reefs by 2050.
Marine scientist Rod Salm narrates a slide show about what's killing coral reefs—and how we're helping protect them.
Dive deep with professional photographer Jeff Yonover in this audio slideshow.
Get the story behind this "Photo of the Month" from Palau.
Arden O'Connor discusses how medicine derived from coral reefs helped save her life.
Divers cultivate threatened staghorn coral at nurseries offshore.
In Papua New Guinea, struggling fishermen are working to preserve some of the world's most pristine coral reefs.