Just in time for World Oceans Day, a new report from NOAA shows the coral reefs are enduring the longest and most pervasive bleaching event on record. Warmer waters are cooking coral, sapping reefs of their color and life.

Ecologists are scrambling to save coral reefs before it’s too late. Believe it or not, the solution could come from 3D printing.

What is coral anyway?

Coral colonies are comprised of tiny, squishy polyps that attach to rocks on the sea floor. Polyps secrete calcium carbonate at their base. Those secretions turn into hard coral, providing the structure of coral reefs. Algae live inside polyps, supplying nutrients and lending coral its vivid color.

When stressed, coral eject their algae and turn white. That’s coral bleaching. If the bleaching isn’t revered, the coral could die. Warmer waters are cause mass bleaching. Making matters worse,

How does a 3D printed reef work?

For years, Humans have created artificial reefs by sinking ships or dropping concrete blocks into shallow waters, providing a rock-like surfaces where coral — along with algae, barnacles, anemones and other species — could make a home. 3D printing improves this with process, producing reefs that better imitate hard coral.

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A 3D printed reef. Source: Reef Design Lab

Marine biologist Kristen Marhaver explained in a TED Talk that baby coral polyps are drawn to “white and pink, the colors of a healthy reef,” and they “they prefer crevices and grooves and holes, where they will be safe from being trampled or eaten by a predator.” 3D printers are working to recreate this environment.

Teams in Bahrain and Monaco have manufactured pastel-colored sandstone reefs with the same shape and texture of coral. Sandstone’s neutral pH makes the artificial reef an attractive destination for baby coral polyps. A forthcoming model from Reef Design Lab will feature a porcelain coating that more closely resembles the chemical makeup of coral.

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That same 3D printed reef eight months later. Source: Reef Design Lab

Some designers have taken a different tack, using artificial coral as a salve for ocean acidification. In her last year at the Royal College of Art in London, Nell Bennett 3D printed coral made of calcium carbonate. When placed in a reef, the artificial coral slowly dissolves, making the surrounding waters less acidic.

Why does this matter?

While coral reefs occupy less than 1 percent of the sea floor, but they underpin roughly a quarter of all ocean life — not just algae and zooplankton, but countless species along the food chain, from crabs to sea turtles. Reefs support fishing and tourism and guard against coastal erosion. Half a billion people worldwide depend on coral reefs for food or income.

Rising temperatures are devastating reefs. Even drastic cuts to carbon pollution will do little to slow their demise. Warming of just 1.5 degrees C would put 90 percent of coral reefs at risk. Scientists project the average global temperature will climb by at least 2.5 degrees C by the end of this century.

Facing a crisis of that magnitude, the only option is to innovate. 3D printing could protect the countless animals that depend on coral, including humans.


Jeremy Deaton writes for Nexus Media, a syndicated news service covering climate, energy, policy, art and culture. You can follow him @deaton_jeremy.