Scientists have discovered behind the Great Barrier Reef a second reef located North of the first one. The new reef had not been seen before because it lies deep below the surface of the waters. It mostly contains bioherms, a circular formation that saves data from over the past 10 thousand years.
The deep-water reef measures about 2,300 square miles, four times the size of London, and according to scientists was hiding in plain sight. But maybe because this new reef is located behind the world’s largest coral reef, people did not suspect more life was near by it. A research team from James Cook University, Queensland University of Technology, and the University of Sydney used LiDAR data from the Australian Navy to map the area.
LiDAR stands for Light Detection and Ranging, and it is a survey technology that measures distance by illuminating a target with a laser light. LiDAR generates three-dimensional information and a detailed map of the zone it is analyzing.
LiDAR revealed there are vast fields of doughnut-shaped mounds behind the Great Barrier Reef that can reach 300 meters across and up to 10 meters deep. These structures are called bioherms and are made of green algae called Halimeda. This type of algae dies and calcifies forming limestone flakes that accumulate information over the years.
Robin Beaman, a marine geologist at James Cook University and collaborator in the research, said bioherms are structures known to be in the northern Great Barrier Reef since 1970s and 80s. He added this is the first time scientists revealed the true nature of their shape, size, and vast scale.
The doughnut-shaped formations have been formed over the past 10 thousand years and can be found from Torres Strait between Australia and New Guinea to North of Port Douglas in Australia. Bioherms can provide habitats for a myriad of marine life, an exciting opportunity for researchers to go for underwater exploration.
The lead author of the research paper, Mardi McNeil, told the Australian ABC News that Halimeda algae could form bioherms shaped like circular rings and sometimes in groups of three or four. He added the shallowest of the bioherms discovered behind the Great Barrier Reef is at 20 to 50 meters deep. McNeil is part of the Queensland University of Technology.
The new discovery could provide a solution to save the Great Barrier Reef from bleaching
According to scientists, the bioherms could help study the Great Barrier Reef, including its formation and the changes it has gone through in the past. The circular structures could also have information about the seafloor changes over the last ten thousand years including the increasing temperature and acidification that it is affecting the largest coral reef in the world.
Beaman told ABC that bioherms are similar to tree rings which can provide information such as the age when they were formed and how was the environment at that time. The new circular structures have 20 meter-thick piles of sediment that can give scientists a significant amount of information about past oceanographic history.
The Great Barrier Reef is facing a massive coral bleaching since last year. The latter almost put this unique ecosystem on UNESCO’s endangered list. Scientists believe the discovery and the data it contains could help understand coral bleaching and how to revert it.
The good news is that reef can recover from bleaching as long as climate changes. Unfortunately, researchers already think that by the end of 2016, up to a quarter of the Great Barrier Reef would have been wiped, which would be chaotic for the environment.
When corals die, everything that depends on them collapses. Fishes have to move out; seaweed moves to other areas, and the reef finally dies. Often, they are lost forever, and the ecosystems change.
Scientists suggest that bioherms are fundamental to prevent coral reef from dying. Others fear the same fate as the great reef for the doughnut-shaped environments.
Jody Webster, an Associate Professor at the University of Sydney, said that because bioherms are also a calcifying organism, Halimeda may be susceptible to ocean acidification and warming. She wonders if the Halimeda bioherms have been impacted and if so, to what extent.
The Great Barrier Reef: A beautiful natural gift
The largest reef in the world is a natural beauty that contains a variety of marine life. It is comprised of over 300 individual reef systems and coral cays. It also has hundreds of picturesque tropical islands with some of the world’s most beautiful sun-soaked, golden beaches.
The Great Barrier Reef is one of the Natural Seven Wonders of the world. It is larger than the Great Wall of China, and it is the only living thing on earth visible from space.
Source: James Cook University