The warming climate guarantees more frequent and more severe ocean heat waves, endangering the already fragile coral reef systems around the world.

When the water temperatures are too high, the coral bleaches. The Great Barrier Reef in Australia, for example, was hit with subsequent major bleaching events in 2016 and 2017.

Recovery of damaged coral reefs is still possible. Small coral pieces, called nubbins, can be attached to frames anchored onto the seafloor to grow and rebuild a reef.

However, to prevent another bleaching event, scientists are selective breeding and genetic engineering to produce "super-corals."

Super-corals are heat-tolerant and resistant to bleaching. They ensure that reefs, which provide shelter and food for several ocean species, would continue to exist.

Heat Resistant Corals

However, in a new study published in the Proceedings of the National Academy of Sciences, scientists reported that super-corals already exist. Megan Morikawa and Stephen Palumbi, the authors of the study, collected samples of heat-tolerant corals in 2014. They transplanted them to sites where coral reefs were devastated by a previous hurricane.

Eight months later, the sites where the heat-tolerant corals were hit by an El Nino event, warming the waters and providing the perfect environment for testing. They reported that all transplanted corals survived the El Nino event.

While previous research claimed that heat-resistant corals exist, the new study published earlier this month is proof that they can be transplanted and they can retain the ability to resist bleaching. The findings suggested that heat tolerance is ingrained within their DNA.

Transplanting Super-Corals Will Not Be Easy

The existence of super-corals gives hope that coral reefs around the world can be saved from the effects of climate change.

While they only occupy 1 percent of the total underwater environment, reefs provide home to a quarter of marine species, including fishes and algae. Losing reefs would be catastrophic for the world's oceans.

However, experts wrote on The Conversations that transplanting heat-tolerant coral nubbins require immense time, workers, and funding to restore reefs. It would take a day to transplant 100 coral nubbins which is not a lot when considering the number of colonies that have already died due to the warming climate. Coran nubbins also take time to grow and form reefs.

The researchers admitted that more study is required to identify the best approach to revive depleted coral reefs.