Mysterious Rings Around Reefs Have No Simple Explanation
While trying to work out how to spend her time while the elements calmed down, Madin happened across a large satellite image of the island and its surrounding lagoon. “It’s a teeming city on the reef and then when you move away, it’s like a desert,” says Madin. The idea is that fish and sea urchins that live within the reefs gobble up anything that grows nearby, leaving bare sand behind.
Source: www.theatlantic.com