National Geographic : 1930 Sep
THE GREAT BARRIER REEF AND ITS ISLES The Wonder and Mystery of Australia's World-Famous Geographical Feature BY CHARLES BARRETT Author of "In Australian Wilds," etc., Editor of "The Victorian Naturalist" IF THE sea went dry along the east coast of Queensland, a thousand miles of coral "maze" would be revealed. The Great Barrier Reef of Australia must not be imagined as a continuous structure, like the Great Wall of China; it is formed by .innumerable reefs, and a map of just one section resembles a complex jig-saw puzzle. Then there are the isles, moun tainous and forested, of the inner zone, and the atolls and cays that are true coral islands. For nearly a century the Great Barrier has intrigued science by the problems that it presents to geologists, physiographers, and naturalists. It has lured such masters of marine zoology as Alexander Agassiz and A. G. Mayer from America, and re cently a British expedition broke camp after a year on Captain Cook's first coral island. In all the Seven Seas there is nothing so wonderful as this vast submarine "cur tain" of coral, the largest coral reef in the world, whose nature and origin re main half-veiled in mystery. A GRAND SEA CANAL Tourists from many lands and thou sands of Australians have made the voy age through "Australia's Grand Canal," the area between the mainland, with its purple hills, and the Outer Barrier. A calm and pleasant trip during a portion of the year, it may be perilous in the cy clone season. Many launches and fishing craft have been wrecked among the coral, or gone down in the heart of a storm within the Barrier. But navigation is no longer the nightmare it was to the early voyagers, before the reef mazes had been mapped and routes safe for even large vessels dis covered. Danger exists still, but the old fear has gone-the haunting fear of dis aster in the Realm of Coral. Majestic is the meeting of league-long rollers of the ocean and the Great Bar- rier. On days when the sunlit water be hind the coral bastion is calm enough for a canoe, mountainous waves pound the reefs unceasingly. The surf on the Outer Barrier at high tide, when the broad reefs' crests are hidden, presents an amazing spectacle. A "long line of boiling surf, springing up in mid-ocean without any apparent cause," is the late Charles Hed ley's description. That great naturalist, whose knowledge of the Barrier was un rivaled, devoted the last few years of his life to the study of its problems. NEPTUNE'S TEETH IN ROWS Swain Reefs, far south, mark the be ginning of the Great Barrier Outer Sys tem. Farther north, the linear reefs are developed. They are some miles in length and up to half a mile across, with broad separating channels. A lighthouse on Lady Elliot Islet marks the southern limit of coral-formed land, "a broad platform of solid coral half a mile in circumference." Then comes an archipelago, the Bunker Group, followed by the Capricorn Group, popular resort now of naturalists, and almost a pic nic ground for holiday-makers from the mainland. Within the Tropics, the maze is multi plied. From a hill at Cooktown, you may see, as Captain Cook did in 1770, the shadows of the coral reefs wherever you look out to sea. The navigator who explored 2,000 miles of the east coast of Australia was ignorant of the existence of coral in those waters when his ship struck on Endeavour Reef at night.* Had the weather been stormy she must have been lost, for coral fangs had pierced her hull. But calm sea enabled the sailors to "patch up" the bark by "fothering," and Cook sailed her to the beach for ca reening and repairs. Meanwhile, gazing from the hilltop, he discovered the coral. * See, also, "The Columbus of the Pacific," by J. R. Hildebrand, in the NATIONAL GEO GRAPHIC MAGAZINE for January, 1927.