Rare good news for besieged corals: giant reef found off Brazil
Good news for reefs: giant coral structure found off Brazil
July 8, 2008
Amid a series of dire reports on the status of coral reefs, scientists announced the discovery of a reef off the southern coast of Brazil’s Bahia state that doubles the size of the Southern Atlantic Ocean’s largest and richest reef system, the Abrolhos Bank.
The find was reported in a paper presented today by researchers from Conservation International (CI), Federal University of Espírito Santo and Federal University of Bahia at the International Coral Reef Symposium in Fort Lauderdale, Florida.
“We had some clues from local fishermen that other reefs existed, but not at the scale of what we discovered,” says Rodrigo de Moura, a marine specialist with CI-Brazil and co-author of the paper. “It is very exciting and highly unusual to discover a reef structure this large and harboring such an abundance of fish.”
The scientists used a side scan sonar — which produces a three-dimensional map of the sea floor — to map the new reef structures in waters ranging from nine to 124 miles (15 to 200 km) off the coast and at depths from 60 to 220 feet (20 to 73 meters).
A report released yesterday by the National Oceanic and Atmospheric Administration (NOAA) shows that nearly half of U.S. coral reefs are in “poor” or “fair” condition. Image shows the west view from Siriba island. Photo by Charles Young.
“Due to their relative inaccessibility and depth, the newly discovered reefs are teeming with life, in some places harboring 30 times the density of marine life than the known, shallower reefs,” said Guilherme Dutra, Conservation International’s director of marine programs in Brazil. “That’s the good news. The bad news is that only a small percentage of marine habitats in the Abrolhos are protected, despite mounting localized and global threats.”
Localized threats include over-fishing, coastal development and large scale land conversion to agriculture, shrimp farms, pollution, oil drilling and sedimentation. Global threats include climate change and ocean acidification.
Coral reefs are besieged by a range of localized threats including coastal development, overfishing, sedimentation, pollution, over collection for the pet trade, oil and gas development, and over-use for recreational activities. On a global scale, reefs are vulnerable to rising temperatures, which cause bleaching, and ocean acidification, which causes changes in reef communities by making it more difficult for some corals to form carbonate skeletons that serve as their structural basis.
The new study urges the expansion of marine protected areas in the Abrolhos.