Climate change is killing coral — can AI help protect the reefs?

Time is running out to save the world’s coral reefs, so conservationists are turning to every tool they can to protect vanishing reefs — including AI.

In Florida, the race is on to restore reefs by “planting” corals raised by humans. It’s an upward battle as rising ocean temperatures stress already struggling reefs. Tracking the progress is essential but tedious work.

In the past, coral conservationists would have had to physically swim out to reefs to take notes on individual corals they’d planted using a pencil and waxy, waterproof paper. “It can’t scale with the scale of your restoration effort. And eventually, you’ll spend more time monitoring coral restoration than you will actually doing coral restoration,” says Alexander Neufeld, a science program manager at the Coral Restoration Foundation (CRF).

Not only is that a time-consuming strategy but also simply taking manual notes on each individual coral risks missing the bigger picture: the health of the reef as a whole. “We don’t focus on the individuals necessarily. We focus on populations, we focus on communities — these broader ecological groups of organisms that we’re trying to restore,” Neufeld says.

That’s where AI can give conservationists a leg up, giving them more precious time to rescue corals while providing new insights into how they can make the biggest impact. It’s the goal of a new tool called CeruleanAI developed by the Florida-based nonprofit Coral Restoration Foundation. The tool uses AI to analyze 3D maps of reefs, giving researchers a new vantage point for monitoring restoration efforts in a warming world.

In Florida, pollution, overfishing, ship damage, and disease have already decimated reefs. There’s been a 90 percent drop in the region’s healthy coral cover since the 1970s. To make matters worse, climate change is killing corals, too. When the water gets too hot, corals expel the algae that give them their color, a phenomenon called bleaching. If the problem persists, the corals — which are animals — die. That’s what happened in the summer of 2023, when water temperatures hot enough to be in a hot tub led to an unprecedented coral bleaching event. CRF lost virtually all of the young corals they’d planted at some reef sites.

Neufeld and the team at CRF are hustling to make up lost ground. To replenish reefs, conservationists can breed new individual corals on land. They can do this by artificially setting the mood for them to reproduce sexually or getting them to clone themselves by breaking coral colonies apart so that each fragment grows into a new colony. Either way, the baby corals eventually need to be “planted” at sea, where the reefs they create support life for thousands of other species.

After planting the young corals, CRF goes back to visit them regularly to see how they’re faring. Over the last several years, CRF has transitioned from taking notes by hand to snapping images with GoPros. Back on shore, they use software to stitch those images together into 3D photomosaics (which you can see in The Verge’s recent video on coral restoration). Neufeld took the idea from his experiences in a college program that used 3D modeling to document shipwrecks and underwater archaeological artifacts.

Applied to coral restoration, the photomosaics help CRF see how well the reef is recovering with the help of the corals they’ve planted. Elkhorn, for example, is considered a “branching” coral that forms dense thickets that become important habitats for other creatures. Success isn’t just about individually planted corals surviving; it’s also seeing them grow and fuse together to blanket the seafloor.

To make the biggest impact, CRF has taken its land-based techniques one step further. They’ve built a tool that leverages AI to gather data from the images they’ve collected. “Wouldn’t it be great if instead of sitting in front of a computer for hours and manually outlining all of these corals, you just have AI scan an image and say, ‘Oh, yeah, that’s an elkhorn [coral] right there’?” Neufeld says.

Now, with the click of a button, they can find out what kinds of species of coral — like elkhorn — are in the reef, where they are in the reef, and how much they’ve grown since CRF’s last visit. It also helps them figure out how to give the corals the best shot at survival and frees conservationists up to spend more time in the water. “We can more rapidly implement changes that need to be made based on what we’re seeing in the data,” Neufeld says.

Soon, conservationists around the world will be able to use the same tools that CRF has developed. The US has pumped millions of dollars of federal funds into restoring Florida’s reefs, working with academic and nonprofit groups including CRF. Many restoration efforts around the world don’t have access to the same resources. CRF plans to launch CeruleanAI early next year, which it says it will offer on a sliding scale or free to other conservation groups depending on how much need they have.

One thing to keep in mind is that, as helpful as this tool can be, the explosion of AI comes with its own environmental footprint. It takes a lot of energy to train AI models, which has some advocates concerned about whether the greenhouse gas emissions from all that computing could make it harder to fight climate change. It’s still too early to tell exactly what the overall environmental toll is, so researchers say it’s important at this point to be mindful about how AI is used — whether it justifies the potential environmental risks.

In this case, at least, AI is helping mitigate the effects of climate change on the world’s oceans — even though there’s a lot of work left to do to keep ocean heatwaves from growing much worse thanks to runaway greenhouse gas pollution.

After historic heat hit the Florida Keys this year, CRF’s monitoring efforts revealed huge losses at some reefs. “We saw that everything had bleached, everything had died, and so, unfortunately, that means that this year was kind of a wash for that part of [the reef],” Neufeld says. “But again, it doesn’t mean that we lost everything everywhere. It doesn’t mean that what we did was wrong in any sense. It just means that we’ve got our work cut out for us going forward.”