The world’s largest coral is longer than a blue whale

The huge coral was discovered in the Solomon Islands

a diver swims over a colorful coral reef

The world’s largest standalone coral (shown) has been discovered off the coast of the Solomon Islands.

Manu San Félix/National Geographic Pristine Seas

Scientists have found a coral that’s so huge it can be seen from space.

This coral was discovered in October off the coast of the Solomon Islands. That’s a small nation in the southwest Pacific Ocean. It’s made of six big volcanic islands and nearly 1,000 smaller islands and atolls. The newfound coral is roughly 34 meters (110 feet) wide, 32 meters long and 6 meters (20 feet) tall. That makes it the world’s largest standalone coral colony.

a map showing the location of the Solomon Islands, north and east of Australia
The Solomon Islands, circled in red, are in the southwest Pacific Ocean.TUBS/Wikimedia Commons (CC BY-SA 3.0)

For perspective, it’s longer than the average blue whale.

Corals are actually groups of tiny animals that live on the ocean floor. A single one is called a polyp. Some types of polyps cluster together to build rigid skeletons out of calcium carbonate. The scientists estimate that nearly one billion coral polyps constructed the newfound coral.

Coral provides a habitat for many sea species, notes coral scientist Eric Brown. He’s part of the National Geographic Society’s Pristine Seas team, which found the coral. Brown spoke about the discovery at a news conference.

“Coral-reef ecosystems comprise only about 0.2 percent of the ocean’s area,” he pointed out. “Yet they contain over 25 percent of the marine species on the planet.”

Manu San Félix is an underwater filmmaker. He came across the giant coral by chance on the night before the Pristine Seas team had planned to leave their location. As soon as San Félix spied the huge coral, he said, “I realized that I was looking at something unique.” In fact, it was so big that the team first thought it was a shipwreck.

The species is known as the shoulder-blade coral, or Pavona clavus. Its shape is made of ridges that look like shoulder blades.

This newfound specimen is much bigger than the next largest-known coral. Called “Big Momma,” that one is just 22 meters (72 feet) wide. It sits off American Samoa, also in the South Pacific.

“Big Momma looked like a huge scoop of ice cream plopped down on the reef,” said Molly Timmers. In contrast, “this newly discovered coral is as if the ice cream started to melt, spreading forever along the seafloor.” Timmers is a marine ecologist on the Pristine Seas team. 

The team measured the coral’s dimensions and reviewed studies on this species’ growth rate. Based on those data, the team now estimates the coral is 300 to 500 years old. Its long life could help researchers better understand conditions during past centuries. That’s because the coral’s calcified skeleton can record data on water temperatures, rainfall and disease outbreaks at the time the polyps were building it.

Here’s a huge, newly discovered coral reef — possibly the world’s biggest.

While the newfound coral appears healthy, coral reefs around the world face many threats. Those range from ocean acidification and plastics pollution to overheating and coral bleaching. To Brown, the new discovery is a reminder that “it’s important for us to do whatever we can to protect these environments that are both small, yet mighty.”

Nikk Ogasa is a staff writer who focuses on the physical sciences for Science News. He has a master's degree in geology from McGill University, and a master's degree in science communication from the University of California, Santa Cruz.