New laser data from the Royal Australian Navy has revealed a massive reef behind the rapidly dying Great Barrier Reef. Giant fields of circular, donut-shaped mounds, between 200 and 300 meters in diameter, are created by a type of green algae. Unfortunately, this reef is likely facing the same threats as the neighboring Great Barrier Reef.
A collaboration between James Cook University, the University of Sydney, and Queensland University of Technology led to the discovery of just how large these fields are. Dr. Robin Beaman of JCU said in his co-authored paper, “We’ve known about these geological structures in the northern Great Barrier Reef since the 1970s and 80s, but never before has the true nature of their shape, size and vast scale been revealed.”
The mounds are bioherms, or organic reef-like mounds, made by the growth of Halimeda green algae. Upon death, they form small limestone flakes similar to the shape of cornflakes and mounds begin to form over time. These Halimeda bioherms are between 200-300 meters wide and 10 meters deep. Thanks to the new glimpse into the area, over 6,000 square kilometers have now been mapped.
The closer look has raised questions of environmental preservation and historical documentation. Associate Professor Jody Webster of the University of Sydney said, “As a calcifying organism, Halimeda may be susceptible to ocean acidification and warming,” and wonders about the extent of possible damage so far. Dr. Beaman is interested in what researchers can learn from bioherm sediment samples about changes in the reef systems over the last 10,000 years. Further impending research will help scientists better understand the structures, their impact, and their future.
Via Daily Mail