Читать книгу Diving Indonesia Periplus Adventure Guid онлайн

44 страница из 170

— David Pickell

A barrier reef that forms around an island is sometimes called an "almost atoll." There can be multiple barrier reefs, extending outward like ripples, and the large lagoon behind a barrier reef can harbor small patch reefs and sandy cay reefs.

Atolls. Some 425 of these characteristic circular reefs, with a large central lagoon, have been recorded throughout the tropics. The vast majority (more than 300) are in the Indo-Pacific. The largest is Kwajalein in the Marshall Islands, which forms an oval 120 by 32 kilometers.

The largest atoll in Indonesia—and the third-largest in the world, just 20 percent smaller than Kwajalein—is Taka Bone Rate, in the Flores Sea south of Sulawesi. Taka Bone Rate (called Tijger in older texts) stretches 72 by 36 kilometers, covers 2,220 square kilometers, and includes 22 sandy islands. "Taka,"probably a Bugis word, is a generic term used throughout Indonesia for atoll or bank reef.

The lagoon of an atoll, because it is so thoroughly cut off from the open ocean, forms a unique environment, and is often much richer in life than the lagoon side of, say, a small barrier reef. The level of organic matter in the water inside the atoll's lagoon is considerably higher than outside, allowing it to support as much as 10 times the biomass as the outer reef edge. And, because it is not adjacent to a large land mass, problems caused by run-off and turbidity are eliminated.