Nov. 2 (UPI) -- Some coral reefs have a stronger genetic makeup to fight off bleaching, a recent study said.

Researchers recently discovered that so-called "robust" coral, which includes certain brain corals and mushroom corals, are capable of producing special amino acids that prevent bleaching.


Other coral, like "complex" coral, have a special relationship with microalgae called Symbiodinium, which helps them to build their hard skeletons. But these robust coral don't need them.

"We now know that 'robust' corals can make at least one of the 'essential' amino acids without relying on Symbiodinium," David Miller, a professor at the ARC Center of Excellence for Coral Reef Studies, said in a press release. "This suggests that they may be more resilient, at least in the short term, to bleaching than the 'complex' corals such as the branching staghorns."

RELATED Reef fish become less aggressive after coral bleaching

The researchers findings were published Friday in the journal Genome Biology.

Many coral draw up to 90 percent of their energy from Symbiodinium, helping them to form their hard skeleton. When a coral feels high temperatures, it loses Symbiodinium, which causes bleaching. Coral bleaching can lead most corals to form a greater dependence on their diet for survival.

"Amino acids are the building blocks of life," said Dr. Hua Ying, researcher at The Australian National University. "They are crucial, for example, in repairing tissue or growing new tissue. But, generating amino acids is energetically costly for animals, so they usually only generate 11 of the 20 required for life. The remaining nine amino acids are called the 'essential' amino acids because they must be supplied by the animal's diet. For corals, this includes tiny drifting animals known as 'zooplankton.'"

RELATED Oyster populations at risk as climate change transforms ocean ecosystems

As Symbiodinium leaves the system of a "robust" coral, its own amino acids kick in to provide it with nutrients.

"Our research also suggests that 'robust' corals are less choosey about which species of microalgae can take up residence in the coral's tissue. The ability to host a broader range of Symbiodinium types could facilitate more rapid acclimation to higher temperatures," said Prof Miller.