July 16, 2008—Zoanthus coral in Brazil's Abrolhos Bank, incorporate sand into their reef-building structure. Last week scientists announced that the bank's reef system—already the largest and most biodiverse in the southern Atlantic Ocean—is nearly twice as vast as previously thought.

"We had some clues from local fishermen that other reefs existed, but not at the scale of what we discovered," Rodrigo de Moura, a marine specialist with the nonprofit Conservation International Brazil, said in a press statement.

It was "highly unusual to discover a reef structure this large and harboring such an abundance of fish," he added.

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