When a massive coral colony was recently discovered in the Solomon Islands, it was believed to be the largest in the world. Then last week, scientists found an even bigger one in the waters off the Indonesian island of Bali.
Coral restoration nonprofit Ocean Gardener announced that Indonesian marine biologists had measured a Galaxea astreata coral colony in Nusa Penida, a popular diving site, at 58 meters wide by 71 long (190 by 233 feet). It’s also 10 m (33 ft) deep and covers an area of more than 4,000 m2 (43,000 ft2).
In comparison, the Pavona clavus coral colony in the Solomon Islands measured 34 by 32 m (112 by 105 ft).
Vincent Chalias, founder of Bali-based Ocean Gardener, told Mongabay in an email, “Large colonies of that species [G. astreata] are quite common, but this one, definitely and by far [is] the biggest.”
Ocean Gardener research and science coordinator Manikmayang was quoted in the announcement saying that, “This discovery has the potential to set a new world record. However, further testing is needed to confirm its status among the world’s giant coral colonies.”
The coral is located in the Lombok Strait where the Pacific Ocean flows into the Indian Ocean, “a central location where corals can grow to gigantic sizes and produce billions of larvae that seed reefs all over the Indian Ocean,” Ocean Gardener said in its post.
Chalias said that although the team knew about the large G. astreata coral colony, it only received training to measure giant corals recently with the “Map the Giants” initiative of Italy’s University of Milano-Bicocca MaRHE Center.
“What was known as ‘coral fields’ are now becoming [recognized as] single organism, coral colonies,” Chalias said. “We are planning on doing some genetics [testing] on it, to prove the one organism theory, but we could also do some aging [tests] on it.”
He said strong currents in the area proved a challenge during their dives, but were also why the coral colony is “well fed.” G. astreata coral is “very well adapted to extract food from the water column,” he said. “The colony shape creates turbulences in the flow, that slows down food, allowing polyps to easily catch preys.”
Despite its size, the coral is vulnerable to climate change impacts and is in its second year of massive coral bleaching.
Eric Brown, a U.S. National Park Service marine ecologist who was part of the P. clavus coral expedition, told Mongabay in an email that “the reproductive potential of large coral colonies is huge,” allowing them to be more resilient and bounce back “from major disturbance events.”
“In addition, the large colony may have a size advantage that enables it to resist disturbance events because some parts of the colony are likely to survive,” Brown wrote.
Banner image of Galaxea astreata coral colony in Nusa Penida in Bali, Indonesia, courtesy of Ocean Gardener.
Credits
