Freezing Coral May Be Ticket to Saving Reefs

The future isn't looking great for corals as the marine invertebrates face rising ocean temperatures, disease, acidic water, and pollution. But MIT Technology Review reports that there's new hope in preserving them, which can bolster and revive future reefs. Researchers have been perfecting methods of cryopreserving coral, a process that pauses time in their metabolic processes. While coral eggs are a tricky nut to crack, freezing larvae has been successful since 2018, and new advances using liquid nitrogen has made thawing them successfully easier. "That's been a huge advancement," says biologist Mary Hagedorn of the Coral Biobank Alliance. "What that means is that we can stop the extinction of species, and in a way that's very user-friendly." One drawback to preserving larvae is the time factor—they can only be collected a few nights per year, when coral spawn.

This means progress in successfully freezing adult corals could be a game-changer. Per Science News, research published in August noted that frozen adult corals survived the thawing process for the first time. However, the Hawaiian finger corals only lasted two days before being overrun by a typically friendly bacteria. Now the team is looking to see how they can boost the sickly corals with antibiotics, antioxidants, and probiotics as they recover from their frozen state. "Think of a patient who's just had open-heart surgery," Hagedorn tells MIT. "They're not going to walk out the door the next day." Her team is also looking into unique solutions to storing the frozen samples, including on cooler parts of the moon. There, the samples could live for hundreds of years tucked in lava tubes and craters.

Corals have been on the decline due to the effects of climate change for decades. A recent report from the Global Coral Reef Monitoring Network says 14% were lost from 2009 to 2018, according to Oceanographic Magazine. "Corals will continue to die, and unless we are replacing them with restoration, there won't be corals available in the future, even if we were to fix all of the threats," Jennifer Moore tells NPR. Working in coral preservation with the National Oceanic and Atmospheric Administration, Moore collects specimens in Florida, then preserves them in tanks as a living library. She believes approaches like cryopreservation are a "big help" to restoring coral in the future. (More on coral reefs).