Rescue Coral Reefs

摘要

In the past 20 years, nearly a third of the world's coral has been destroyed. Around 90 percent of the reefs off the coasts of Sri Lanka, Tanzania, Kenya, the Maldives and the Seychelles are at risk. If ocean temperatures rise by another 7°F in the next three decades, as is predicted, 95 percent of the Great Barrier Reef will disappear. The primary cause of the die-off is coral bleaching. As temperatures rise, marine bacteria flourish and attack the algae that live symbiotically within every individual coral polyp. The algae photosynthesize sunlight into energy (in the form of sugars) for their hosts and give coral its color. When the algae dies, what's left is a ghostly white. Some corals in the Red Sea and the Persian Gulf have avoided this fate, although no one knows exactly why. Eugene Rosenberg, a microbiologist at Tel Aviv University, has proposed that the presence of a different form of bacteria is what has made the difference. "Coral has thousands of bacterial species living within it, just as humans do," he says. "These bacteria can help coral adapt to environmental changes."