From the boat, there’s nothing remarkable about the place — just choppy water and a white mooring ball, a few miles offshore. But once we’re underwater, I can see the rows and rows of PVC trees, suspended above the sand in a grid that stretches away into the distant murk.

This is a coral nursery. Each tree bears a ripening crop of a hundred or more pieces of coral. The smallest fragments are pinkie-sized, twirling on their tethers as other divers kick by; the largest hang like many-limbed chandeliers, turning slowly in the current. When I get closer, I can see the individual polyps, the anemone-like creatures that make up each fragmented colony. Nestled in the crenellated openings in their solid skeletons, they are waving their fleshy tentacles through the water, feeding.