Finding heat-resistant corals could be a life buoy for Australia’s endangered coral reef region.

Now the world’s largest coral reef is experiencing heat stress, which is causing the reef to wither and eventually die.

Researchers from the Australian Institute of Marine Sciences published their findings Tuesday in the journal Nature Communications† In it, they describe a model they developed to predict, using breeding experiments, camera imagery and artificial intelligence, that in reefs there are corals that can withstand rising sea water temperatures. They estimate that hundreds of corals – about 7.5 percent of the total Great Barrier Reef – may form the basis of offspring corals that are highly heat-tolerant. Corals are found from the northern and central part of the Great Barrier Reef.

Knowledge about these reefs could form the basis for attempts to restore the Great Barrier Reef at least in part. By doubling down on heat-tolerant corals, large portions of the reef can be preserved. The authors, including Dutch marine biologist Madeleine van Oppen, suggested that their findings could be of great importance to coral reef restoration worldwide.

Coral bleaching occurs when polyps expel algae in their skin due to heat stress. Just last week it was announced that the Great Barrier Reef had experienced serious coral bleaching. Sea water temperatures have been two to four degrees Celsius above normal in some places in recent summer months.

The Great Barrier Reef has experienced coral bleaching before, damaging about two-thirds of coral reefs in 2016, 2017 and 2020. Coral bleaching is the initial stage of coral dying.

Eric Meisters, a marine tropical ecologist at Wageningen University & Research (WUR) who was not involved in this research, cites the article in Nature Communications “Very high quality.” “On the positive side, it shows that corals are far from dying and that we may be able to affect their resilience to climate change in the form of rising seawater temperatures,” says Meesters.

On the other hand, he says, the research is mainly based on one type of coral and only five reefs. Although this approach can easily be extended to other species and regions, “coral reefs are complex systems and this makes predictions quite uncertain.”

According to Meesters, there’s a good chance that researchers overlook some related relationships: predictions are based on the ecosystem and the processes we know about. “In the future, these conditions may change so much that the model’s predictions become completely wrong,” says Meesters.

For example, according to him, massive mortality combined with an abundance of nutrients already occurring in many places in the GBR can lead to strong algal blooms on the bottom. “This can make it difficult for coral larvae to find a place to settle,” Meesters says.