In a discovery that significantly shifts scientists' thinking about coral formation, researchers have found a vast coral reef deep in the Atlantic Ocean some 160 miles off the coast of Charleston, South Carolina.

The reef was discovered Aug. 23 by scientists aboard a deep-diving research submarine known as Alvin. It's about half a mile beneath the surface and about 85 miles long.

"It was a thrill to see these newly discovered habitats firsthand," Erik Cordes, a Temple University biologist and one of the scientists who made the discovery, told NBC News MACH in an email. "Every dive in Alvin is different, and we always expect to find something new. But I have never found something this significant, something that profoundly changed our concept of where these habitats could exist."

It's long been known that Lophelia pertusa, the dominant species of coral that the scientists discovered, exists in shallower water off the U.S. coast from Florida to North Carolina. But the existence of the whitish "stony" coral in deep water farther from shore suggests that these coral habitats may be linked to one another and thus may be more resilient than previously thought to rising water temperatures and other environmental changes that threaten coral around the world.

"If coral reefs are disconnected from other places and get damaged, they're finished," said Murray Roberts, a University of Edinburgh marine biologist and an expert on corals who was not involved in the discovery. "But if they're connected, then there is a potential for recovery."

In light of the unexpected find, Cordes said scientists should expand their search for coral to other parts of the ocean, adding that the discovery should also be taken into account by government agencies responsible for managing sensitive marine environments.

Erik Cordes inspects a box of coral specimens after a dive. The white corals are Lophelia pertusa, and the orange are Madrepora oculata. DEEP SEARCH 2018 - BOEM

In January, the Trump administration announced a plan to expand offshore drilling for oil and natural gas — activities that Cordes said can have "significant, adverse impacts on these habitats." The plan was met with widespread opposition.

The coral reef was discovered during the course of an almost eight-hour dive by Alvin, which is owned by the U.S. Navy and operated by the Woods Hole Oceanographic Institution. Also on board for the dive were Catherine McFadden, a biologist at Harvey Mudd College, and the sub's pilot, Bruce Strickrott.

The research that led to the discovery is part of Deep Search, an ongoing ocean research initiative funded by the National Oceanic and Atmospheric Administration, the U.S. Geological Survey and the Bureau of Ocean Energy Management.

For now, the reef appears healthy and is home to large numbers of fish, including a swordfish that was seen swimming over the reef. And its discovery could be a prelude to more discoveries of coral reefs in the Atlantic.

"What's off Africa?" Roberts asked. "What's off South America? There will be many more such discoveries, I would predict."

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