The world’s coral reefs — the largest being Australia’s famous Great Barrier Reef — may be facing drastic changes due to global warming, but there’s some good news.
A massive, doughnut-shaped coral reef was discovered in northern Queensland, just behind the Great Barrier Reef, CNN reports.
Scientists at James Cook University, the Queensland University of Technology and the University of Sydney announced that they had found a large field of unique-looking round mounds using laser data from the Australian Royal Navy.
Mardi McNeil, a lead author on the study from the Queensland University of Technology, calls the reef system is “vast.” McNeil says,
We’ve now mapped over 6,000 square kilometers (about 2,300 square miles).
She adds, “That’s three times the previously estimated size, spanning from the Torres Strait to just north of Port Douglas.”
The unusual structures are made by a kind of green algae called Halimeda bioherms, the scientists say. When the algae die, they create white cornflake-like residue of limestone that built up over time to form giant rings 200 to 300 meters across and up to 10 meters deep each.
Robin Beaman, a member of the team and a professor at James Cook University, says there has been evidence since the 1970s and 80s that these reefs existed, but there has been no information on their exact shape, size, and scale. “The deeper seafloor behind the familiar coral reefs amazed us,” he says.
The scientists note that less than 15% of the Earth’s oceans over 200 meters deep have been mapped.
Beaman says that these rings could reveal some insights on the history of the Great Barrier Reef, in the same way that tree rings can tell a lot about a tree’s environment and age. The sediments on the reefs, he says, “can tell you an awful lot about past oceanographic history.”
The discovery comes after news that 90% of the Great Barrier Reef is showing signs of bleaching, a phenomenon made worse by the year’s extremely hot temperatures.