Coral bleaching looks exactly like what you’re envisioning right now: white, bleached out coral reefs, which is quite a departure from the colorful structures we all know and love. Reefs make up less than 1 percent of Earth’s undersea ecosystems, but don’t belittle their importance: They shelter 25 percent of marine species, protect shorelines, support fishing industries, provide tourist dollars, and could be home to the next big, undiscovered medical breakthrough. Even those who live far from the coasts can help protect coral reefs.