The deep reef
The team persevered and brought one precious Leptoseris coral sample back to sea level. Typically, such corals peter out in the Great Barrier Reef above 330 feet (100 m), replaced by non-light-dependent sponges and sea fans. Using the ROV, the team also found the deepest Staghorn Acropora, a type of coral that makes up the majority of most of the world's reefs.
"These discoveries show just how little we really know about the reef and how much more is yet to be discovered," Bongaerts said. "This poses lots of questions for us, but now we have specimens, we'll be able to analyze them much more closely and can expect our findings to reveal a far greater understanding of just what is going on to enable reef corals to survive at such extreme depths."
The Great Barrier Reef has been in decline, with half of it vanishing in the last 27 years, according to a study
released in the journal Proceedings of the National Academy of Sciences last October. Climate change is boosting the temperature of the oceans, causing some of the damage. Another reef foe is the crown-of-thorns starfish, which eats coral. The starfish populations have exploded because of nutrient runoff from agricultural fertilizers.