Can You Hack Coral to Save It?

As sea levels rise and megastorms become more frequent and intense, answering that question might be the key to preserving coastal life as we know it

Could cloning coral save Florida Keys reef? (Dylan Fant)

On September 10, 2017, as Hurricane Irma drowned the Florida Keys with a five-foot storm surge and shredded houses with 130 mph winds, David Vaughan, a 65-year-old marine biologist, and Frank Slifka, a 67-year-old maintenance man, huddled inside the Elizabeth Moore Center for Coral Reef Research and hoped for the best. There were not many places to hide on the tiny spit of sand called Summerland Key, but the research center was one of them. The $7 million facility was built to withstand a Category 5 hurricane and resembles a cinder block on burly concrete stilts. From the second floor, Vaughan peered into the storm to check on his house and boat next door. All he could see was the wind itself, a roaring wall of gray.

When the storm’s eye passed directly overhead, the wind died and the storm surge sucked back out to sea. Vaughan could see that his house’s roof had begun to collapse. His boat had smashed into his Prius. He had 40 minutes to save what he could before the back wall of the hurricane hit and another storm surge rushed in.

He and Slifka rushed downstairs, turned their backs on everything Vaughan owned, and got to work in the laboratory’s ground floor, rescuing thousands of tiny plaster plugs capped by dark dots the size of a pencil tip—genetically hacked coral polyps that the storm threatened to wash away. Without them, Vaughan knew, the Florida Keys might not survive the next century.


When I drove into Summerland Key three months after the storm, debris still lined the main road, piled almost as high as the three-axle trucks rumbling in to retrieve and burn it. Just 20 miles east of bustling Key West, the island remained a ghost town. Boats and trailers sat marooned on front lawns, their carcasses spray painted with the redundant tag “trash.” Many residents hadn’t returned to clean up.

The Elizabeth Moore Center's parking lot, however, was packed with cars. The building had survived the storm. Inside its thick concrete walls, offices and dorm rooms thrummed with the paperwork doldrums of scientific life. Down in the open-air ground floor, the plastic holding tanks that had overturned in the storm once again brimmed with the corals Vaughan and Slifka had saved, plus thousands of others, submerged in bubbling seawater. Grad students slowly circulated among them, staring down into the troughs, gliding suction hoses along their bottoms.

Mote's strategy hinges on farming coral in a lab. (Courtesy Dan Mele/Mote Marine Lab)
Coral must be broken apart to regrow separately. (Courtesy Dan Mele/Mote Marine Lab)

When I wondered aloud about their job, one perked up and removed his headphones. “We’re removing detritus from the bottom,” he said.

“Snail shit,” said another.

Suctioning snail shit is where the rubber meets the road for the facility’s main mission: saving coral from extinction via a groundbreaking technique of genetic modification and cloning.

Corals are strange creatures, invertebrate organisms made up of individual tentacled polyps that, under a microscope, each look like a miniature Sarlacc pit. Inside each polyp are tiny marine plankton that photosynthesize food, giving the polyp enough energy to build a calcium carbonate reef structure around itself and its neighboring polyps.

They’re also fragile. Without grad students to suction up snail shit at this stage of their lives, the polyps would be strangled by too much algae. Without carefully monitored water temperatures, the polyps would overheat and expel all their algae and bleach, a much greater danger that leads to wide-spread die offs.

Vaughan, the executive director of the Elizabeth Moore Center, has a graying castaway’s beard and cloudy blue eyes. He commutes to work every day by paddling a canoe 50 yards across Summerland Key’s canal from the dock at the back of his house, which is still standing. “People say, ‘You’re the best low-carbon-footprint commuter,’” Vaughan said. “They don’t even know that I hold my breath going across, so I’m not emitting anything at all.”

Vaughan giggles—he does that—but he’s getting at something. Since the 1970s, the greenhouse effect from the atmosphere’s absorption of carbon dioxide has raised average ocean temperatures by almost two degrees Fahrenheit. In the next 100 years, that temperature could rise by between two and six degrees more. Worse, the sea has absorbed about half of humanity’s total CO2 output, which has chemically reacted with the main substrate of the ocean, calcium carbonate—a compound that all sea animals with exoskeletons, like crabs, shrimp, clams, and coral, depend on to live—to make oceans 30 percent more acidic than they were in the 19th century. That higher acidity makes it harder for coral to build its reef structure. If ocean acidity continues to increase into the next century, it could mean reefs will begin eroding faster than they are being built—or, literally, start melting away.

The combination of warming and acidification has been devastating to coral. Since the 1970s, scientists estimate 20 to 40 percent of the world’s coral has been killed off by bleaching events caused by high water temperatures. In certain areas, it’s been worse. In 2015, 22 percent of the Great Barrier Reef, one of the world’s largest living structures, died off in a mass bleaching event. A 2008 study estimated that only 2 percent of Florida’s native staghorn and elkhorn corals remain alive. And bleaching events worldwide are happening more often as earth’s average temperature climbs. Florida’s reefs have experienced bleaching events in 12 of the past 14 years.

The effects of this mass extinction are catastrophic. Never mind that reef tourism generates $5 billion annually in Florida and $36 billion worldwide. Across the globe, hundreds of millions of people depend on fish stocks that are supported by the coral reef ecosystem, without which they’ll starve.

What’s more, if reefs disappear, millions of people living in these low-lying coastal regions, including the Keys, could be displaced—or drowned—by megastorms like Irma, which the National Oceanographic and Atmospheric Administration (NOAA) believes will only get stronger in coming years due to warming ocean surface temperatures. These communities depend on fringe and barrier reefs, where corals rise like a wall from the seafloor, beating back the strength of incoming waves like defensive linemen breaking up an oncoming blitz. A study during Hurricane Wilma in 2005 found that barrier reefs attenuated 99 percent of the height of the storm’s 42-foot waves before they hit the shoreline. But the reefs pay a price for their work. Before Irma smashed into the Keys, many of its fringe and barrier reefs had been covered in hard and soft corals. Now, said Robert Nowicki, a postdoc research fellow at the Mote Marine Laboratory, the organization that runs the Elizabeth Moore Center, some of them had been “scoured almost to nothing, like the surface of the moon.” If there’s no new coral to replace the old, life as we know it along the world’s tropical coasts will almost certainly change.

Mote volunteers planted 500 Stagorn Coral on Hope Reef in June 2017. (Courtesy Conor Goulding/Mote Marine Lab)
Coral replanted by the Mote Marine Lab (Courtesy Joe Berg/Mote Marine Lab)

“Twenty-five-to-30-foot waves were hitting our reef during Irma,” Vaughan told me. “If those waves had not been smashed on the reef, then they would have smashed on our island, right here. I think our tallest buildings are 33 feet. So where would anybody run to?”

In the past five years, all these disastrous consequences for reefs have pushed coral reef restoration to the forefront of marine science. The field is expensive and controversial, but today, it’s considered the tip of the spear in the fight to help coral survive into the next century.

Scientists like Ruth Gates, director of the Hawaii Institute of Marine Biology, have recently made major strides in identifying and crossbreeding the genotypes, or genetic families, of each coral species that can survive the higher temperatures and acidification we can now expect in the coming years—temperatures and pHs that will kill and then dissolve many of the world’s less-hardy corals. The goal is to create a “super coral” that will survive an increasingly inhospitable ecosystem.

Vaughan and his team are part of this search for genetically superior corals. But their main contribution is what Vaughan calls his microfragmentation program, which both clones corals and hacks the mechanisms for their growth rates. “We can fix things that we thought impossible ten years ago,” Gates told me when I asked her about Vaughan’s work. “Really, his techniques are at the center of the question, ‘How do we build a reef?’”


Vaughan’s technique is absurdly simple: He uses a saw to chop healthy hard coral pieces into much smaller fragments; these grow back extremely quickly atop small concrete plugs and are then replanted in the sea. In essence, he’s created a sea-life version of Mickey Mouse’s broomsticks in the Sorcerer’s Apprentice. Smash them up, then watch them come roaring back with a vengeance.

The technique is a vital one for the field. Coral’s biggest problems might be warming seas and rising acid levels, but those are magnified by a sad fact of life for corals: They aren’t very good breeders. “We actually didn’t know how corals reproduced until the 1980s,” Vaughan said. That’s because, as if adhering to some dirty fairy tale, corals breed only a few days a year, en masse, for around 30 minutes, shortly after the full moon in August, when they simultaneously fill the sea with their white, snowy-looking gametes in a single, very unkinky orgy.

Because of this sex tactic, only one in a million potential baby corals is successfully fertilized and survives to become a juvenile. That means it takes some corals 25 or even 50 years to successfully reproduce. Given the rate of the ocean’s decline, that’s not going to produce the genetically superior corals nearly fast enough. “We’ve probably got 50 to 100 years to act with these resistant strains of coral,” Vaughan said. “If we still don’t change in 100 years, and it keeps getting hotter and hotter—there’s certainly a limit to everything.”

Vaughan stumbled on his procedure five years ago when he accidentally broke a piece of coral in his lab and left it in the bottom of the tank. When he returned two weeks later, it and the other fragments had regrown to their original size. He’s still not sure exactly why this happens, but his closest analogy is our skin cells, which regrow quickly to cover a fresh wound but otherwise lay dormant.

Using jewelry saws, Vaughan and his team started fracturing their lab-fertilized corals. Within three to six months, they could turn a single coral into 60 to 100 new organisms the same size as the original. The fractured corals continued to grow between ten and 40 times faster than coral in the wild, depending on their species.

Then Vaughan made a much more important discovery. Because the polyps were technically all part of a single organism before they were fragmented, they were clones—and they would willingly reconstitute back into a larger organism, skipping ahead into maturity. “Usually, when corals touch each other, they start fighting, and they can kill each other,” Vaughan said. “But when we put 100 of the fragmented pieces next to each other that had come from a single original piece, they didn’t fight. They recognized each other as themselves. And they would actually start to fuse together, like skin grafting.”

A piece of coral the size of a golf ball, fractured into 20 pieces replanted side by side, could produce a single large coral the size of a pizza just four to five years later. It worked in the wild, too. In four years, Vaughan could have a sexually mature coral the size of a football or a table—depending on how many individual pieces of coral he decided to combine—which would have taken a natural coral 25, 50, or even 100 years to grow.

These quick-growing fragmented corals could be planted near one another in the wild to cross-breed and create uber-corals resistant to high water temperature, ocean acidification, and disease. When paired with the work of genetics-focused scientists like Gates, it would be like replanting a rainforest that could continue to proliferate, with offspring that grew bark strong enough to break a logger’s chainsaw.

Vaughan set a goal to plant a million corals before he retired. He and his team grew their coral output exponentially, planted multiple offshore nurseries, began making their reef-growing techniques cost-efficient, and started working to score the major state grants needed to rebuild Florida’s reef industry.

Then the hurricane hit.


Working quickly, Vaughan and Slifka saved the vast majority of the coral plugs outside the Elizabeth Moore Center—some 5,000 out of nearly 7,000. Inside the lab, another 14,000 corals rode out the storm, along with a gene bank holding the most promising genotypes of all 28 coral breeds found in the Keys.

Out in the field, acres of wild corals were sandblasted by the storm’s waves. One of the lab’s field nurseries for lab-fractured elkhorn and staghorn corals—more fragile, branching corals that look like antlers and are endangered in Florida—was almost entirely wiped out. “It was pretty disheartening,” said Erich Bartels, a staff scientist. “That coral was the result of 500 hours of work per person, per year, for seven years.”

But another field nursery for the lab’s elkhorn and staghorn farther south fared much better, with only minimal losses. And the lab’s hardier boulder corals also had a higher survival rate. “All we can do is plant as many good corals as we can," said Nowicki, "use the numbers game, and spread everything out so that a single storm can’t destroy everything we’ve done.”

Vaughan still says he won’t retire until he plants his million corals worldwide. Upscaling the process is beginning to pay off. The cost per coral has dropped from around $1,000 a piece to only $20 a piece, thanks to more efficient methods. The lab already has grants to plant between 25,000 and 50,000 corals in 2018, and by spreading his techniques to local coral restoration labs worldwide, Vaughan hopes to quickly catapult those numbers into the hundreds of thousands per year. He and his team are hoping to change the public’s attitude toward saving reefs, which, since the Great Barrier Reef’s die-off in 2015, has shifted toward hopelessness.

“One of the things that disheartens me the most is people saying, ‘Oh, we’re screwed. Planet’s over. There’s nothing we can do,’” Nowicki said. “There are things we can do. But you have to have the courage and the resources to go out and try.”

On my last day at the lab, I found Frank Slifka, the maintenance man who stayed behind to weather Irma with Vaughan. Slifka was working in the bowels of the facility, where the tidal surge had swept through during the storm, cleaning up and keeping track of diving equipment in metal wire cages.

“People ask why we stayed behind,” Slifka told me, shaking his head. “We weren’t trying to be brave or heroic or anything like that. We just decided that if we were really here to save the coral, then that’s simply what we needed to do.”

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