In the shadow of volcanoes
At dusk the Lembeh Strait seems lit by fireflies as fishermen in outriggers use kerosene lanterns to attract baitfish for the tuna fishery far offshore. Sulawesi sits in the middle of the greatest concentration of coral reefs on the planet—a virtual coral Eden—so diving in Lembeh Strait can seem an ironic contrast. But this little-studied world between the reefs and the rain forests is also a rich environment. A deepwater upwelling in the Molucca Sea pushes a vital plankton broth south into the ten-mile-long (16.1 kilometers) strait, and rivers running down through Sulawesi's forests also add nutrients. Whale sharks and manta rays once cruised here, but they were fished out. With those attractions gone, divers and then scientists turned their attention to the bottom, and were astounded by the profusion of life. Yet the strait can't be called pristine. The port of Bitung has nearly 145,000 people, and the heavily traveled waters gather trash. Paradoxically, this has benefits: On the strait's otherwise featureless bottom, tires, bottles, cans, and old shoes all become some creature's habitat.