National Geographic : 2004 Feb
A RAUCOUS CLOUD OF TERNS hovered over Kanton island, calling out in high-pitched screeches. Beyond the low sandy atoll, the South Pacific stretched forever beneath tropical clouds topped by immense crowns of gold, red, and white. It was 6:30 a.m., and biologists David Obura, Sangeeta Mangubhai, Mary Jane Adams, dive master Cat Holloway, and I adjusted our scuba gear as we sat on the pontoon of the gently rocking skiff. "This is definitely the spot," David said. "Let's hope they're here." I bit onto my regulator, grabbed my under water camera, and fell backward into the island's narrow lagoon entrance. The others followed, and we descended 70 feet to the bot tom. Streaming through the water, the morn ing sun brightened the yellow, green, and purple corals around us. A manta ray and a green turtle nosed nearby as if curious. Then, like the start of a breeze, the water began to move. Nearly imperceptible at first, the strengthening current gradually diverted our bubbles at a slight angle as they ascended. The flow increased steadily and a roar re placed the peaceful silence as water began to gush out the lagoon's entrance into the ocean on the full moon ebb tide. Cued by this outgoing current, a school of perhaps 5,000 Pacific longnose parrotfish gathered around us and started to circle. Our bubbles were flowing sideways now as we clung to bottom rocks, and our hair and dive gear flapped and fluttered in the torren tial tide. If we had let go of the rocks, we would have been swept out into the ocean. The foot-long parrotfish tightened their school and swam faster. This was what we had come here to see: the periodic spawning of the parrotfish on the outgoing tide. Within the group, a few fish swam faster and shook, stim ulating the entire school to spiral and bolt upward, releasing ecstatic bursts of eggs and sperm along the way like biological fireworks. The egg and sperm clouds they left behind were so dense they dulled the penetration of sunlight through the water. Again and again the fish repeated this act, spiraling toward the surface every ten to fif teen seconds. For almost an hour the school exploded in a rite of reproduction, relying on 54 NATIONAL GEOGRAPHIC * FEBRUARY 2004 the fast ebb tide to carry the fertilized eggs far out to sea, where they would be safer from predators. As I watched from the sea floor, a large shadow passed over me. A half-ton manta ray, hovering magically and somehow unmoved by the current, was feed ing serenely on the parrotfish eggs and sperm. TOO SOON, our nearly empty air tanks forced us to return to the surface and our waiting skiff. "Incredible-I've never seen anything like it!" said David, a specialist in coral reefs who has spent more than a thousand hours under water studying ocean life. I also was deeply moved. As vice president for global marine programs at the New England Aquarium, I've made it my goal to find Earth's last pockets of primal ocean, those underwater havens that have remained unspoiled as long as the ocean can remember. Here in this lagoon we had dis covered such a place. We'd motor-sailed five days out from the Fiji Islands to reach the Phoenix archipelago: eight small islands, including Kanton, strung like jewels on an irregular necklace. The islands cover 25,000 square miles of the Pacific, about one-fifth the area of Australia's Great Barrier Reef, and are part of the Micronesian country of Kiribati (pronounced KEE-ree-bas). Most of the 93,000 people of Kiribati don't live on the Phoenix Islands. All but a few live 600 miles to the west on the Gilbert Islands or 1,000 miles to the east on the Line Islands. Kanton is the only permanently inhabited island in the Phoenix archipelago. But what they lack in human population, the islands make up for in animal life, much of it revolv ing around magnificent coral reefs that keep marine biologists like me awake at night thinking of undiscovered species they shelter.