Could Underwater Autonomous Robots Save Coral Reefs?

Reef restoration is a slow process, with divers planting coral fragments one at a time by hand. But roboticists are now developing automated planters that could change the game

Ryan Hesketh, bioGraphic

April 30, 2026

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On Isla Grande, a bone-white island in Colombia’s Rosario archipelago, diving guides have gone out almost every day since 2018 to plant coral seedlings. Scattering the seafloor with “cookies”—small concrete disks laced with coral seedlings—these underwater gardeners managed to restore a significant portion of their island’s reef. Until, that is, a mass bleaching event hit in 2023.

“We lost it all. Everything,” says Lavinia Fiori, one of Isla Grande’s guides and the architect of its restoration project.

The future of corals is dire indeed. Around the world, coral reefs are collapsing. From 2024 to 2025, the northern reaches of Australia’s famed Great Barrier Reef lost nearly a quarter of their coral cover. Between January 2023 and September 2025, extreme heat bleached 84 percent of reefs worldwide. For ecosystems that cover less than one percent of the seafloor, the consequences have been and will be devastating. A quarter of all marine species depend on coral reefs for survival, while half a billion people rely on them for food and income.

“This is the first time we are at risk of losing an entire branch of the tree of life,” says Alex Neufeld, the science program manager at the Coral Restoration Foundation (CRF), a Florida-based conservation organization. “It would be like losing trees. Not some trees—all trees.”

The customary approach to rebuilding degraded reefs—divers planting coral fragments one at a time by hand, as they did at Isla Grande—can’t keep pace. Even massive projects, like the $10 million Mars Coral Reef Restoration effort, which has been working since 2006 to restore roughly 27 acres of reef habitat globally at a rate of about 440 yards of reef per day, barely seem to register against the scale of loss. “The work is slow and takes a lot of labor,” says Edwin de la Rosa, a member of Isla Grande’s nativos, or Afro-Colombian, community and one of its coral restorationists. “We have to go out every day to care for the coral. We spend a lot of time in the water.”

Given the slow pace of reef restoration projects, the math just “doesn’t math,” says Ian Enochs, the coral program lead at the U.S. National Oceanic and Atmospheric Administration’s Atlantic Oceanographic and Meteorological Laboratory in Florida. But researchers, including Enochs, think there’s a better way to secure corals’ future: What if, rather than coral reef rehabilitation remaining a tedious and difficult manual process, conservationists could harness robotics, artificial intelligence and autonomous vehicles to transform it into an industrial-scale endeavor?

Robotics expert Benjamin Moshirian, with the Australia-based Reef Restoration and Adaptation Program, is among those leading the charge. He’s spearheading the development of the Deployment Guidance System (DGS)—the world’s first automated underwater coral planter.

“You could call it an ocean tractor,” Moshirian says.

Attached to a vessel roughly the size of a fishing boat, a DGS can either be piloted by a crew or left to operate autonomously. A camera coupled with artificial intelligence identifies suitable planting sites. When it spots the right mix of conditions below—the right seafloor substrate, the right depth and the right water flow rate—a dispenser mounted to the back of the craft drops a ceramic plate bearing a coral seedling. The whole process takes about half a second, far quicker than any human diver.

The DGS should also trounce existing techniques when it comes to cost. Over the course of its operational lifetime, Moshirian says, each DGS will be able to deploy around a million coral seedlings at a cost of roughly U.S. $1 per seedling. This is far cheaper than existing techniques, like those used by the Mars Coral Reef Restoration team, which land at around $8 per seedling.

Alongside his work on the DGS, Moshirian is spending his spare time developing a “DGS Lite”—a budget version built using GoPros and other consumer hardware. It’s important to him, he says, to make an accessible version of the device that smaller projects can afford.

Regulations permitting, Moshirian hopes to one day see a DGS running night and day, largely without human input. “It’ll disperse five juvenile corals per square meter, constantly,” he says. “How else could we hope to achieve that?”

But getting coral seedlings into the water is just part of the challenge. With ocean temperatures rising, securing corals’ future means seeding the sea with specimens equipped to thrive in increasingly harsh conditions. “What’s the point in planting more if they don’t survive?” Neufeld says. “You can seed a million corals and lose them all in a single bleaching event.”

This is where Enochs comes in with his coral-stressing robots.

At his Florida lab, Enochs has corals on a heat-exposure regimen. After his team collects healthy corals from a reef, they break the samples into fragments and allow them to adjust to life in tanks. Once the pieces acclimate, the stressing process begins. Enochs and his team gently heat the water to levels that would usually damage the corals. Their goal is to cause temporary heat stress, toughening the coral fragments up to survive much warmer oceans. Some wither; some endure. Those that survive are the genetic lottery winners and get planted back into the reefs, where they will multiply and produce descendants with a better chance of surviving a mass bleaching event.

Finding these heat-hardy corals “is a needle-in-a-haystack kind of search,” Enochs explains. “We’ve got to be evaluating orders of magnitude more coral … than we have in the past.” Work at that scale can’t be carried out by hand, which is why he brought robots into the fold.

Enochs emphasizes that he’s not an engineer—“just an ecologist trying to solve a problem.” Regardless, he’s built a lab that brings production-line thinking to coral restoration. It looks like a Ford factory, with quietly whirring robotic arms and screens displaying complex readouts.

“We know that we can stress-harden corals,” Enochs says. “We know that we can grow corals fast in the lab. We know that we can identify resilient genotypes. We know all of these things. But we’ve got to do a lot of it.”

Melanie Olsen, who leads the ReefWorks program for the Australian Institute of Marine Science, sees the future of coral restoration involving fleets of robotic systems working together: flying drones mapping reef health, autonomous submersibles scanning reefs’ delicate structures and surface vessels coordinating operations. She envisions autonomous craft mapping reefs with a regularity that, if done manually, would be all but impossible.

The robots are almost ready. They have electronic eyes, ears, brains and hands. They can work faster, longer and more precisely than humans. But on Isla Grande, coral-assisting robots feel very far away.

Fiori, who has spent more than a decade working alongside Isla Grande’s nativos community to save its reefs, understands the technology’s allure. “Sure, robots would be nice,” she says. “Of course we want help! But where is it?”

Across the planet, most coral restoration projects are small, community-based and chronically underfunded. “I think imagining that just robots will save us could be optimistic to the point of being harmful,” Neufeld says. “There’s never a silver bullet.”

Indeed, Phanor Montoya-Maya, the reef restoration program manager at CRF, points out that the problems facing coral reefs extend beyond what technology alone can solve. Addressing the fundamental underlying issues—warming oceans, acidification and pollution, among others—requires political will and community buy-in.

“If technology is imposed, then we need [community] participation,” Montoya-Maya says. “Restoration succeeds not only because the corals survive, but because of the relationships, the trust, and the stewardship built in the process.”

The robots are coming. Will they be able to save the world’s ailing reefs? Time will tell. But as Montoya-Maya says, with determination written across his face: “Until I see the last coral die, there is hope.”

This story originally appeared in bioGraphic, an independent magazine about nature and regeneration powered by the California Academy of Sciences.