Fields of maricultured Acropora in Onna, Okinawa, JapanOkinawa, Japan is known for its great diving and lush coral reefs. Going into it, I didn’t know what to expect with this dive. I’ve heard all sorts of cautionary tales about diving in Okinawa due to its strong currents, but I’ve also heard that the quality of the reefs is practically unmatched. The day of my scheduled dive was rough. It started raining heavily, and that pretty much limited the dive locations that were available for safety reasons. The single dive location would be just off the coast of our hotel in the Manza Beach area of Onna-son. Onna is located in the central part of the island and is where most of the resort hotels are located.
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