Scientists Turn to 3D Printing to Save Devastated Coral Reefs

Artificial corals could help dying reefs regenerate, but they’re not a replacement

A diver looks at reef of a major bleaching on the coral reefs of the Society Islands on May 9, 2019 in the Polynesian Islands
A diver looks at reef of a major bleaching on the coral reefs of the Society Islands on May 9, 2019 in Moorea, French Polynesia. Photo: Alexis Rosenfeld/Getty Images

In March of this year, Australia’s Great Barrier Reef experienced its worst bleaching event on record. About a quarter of the coral on the reef expelled the algae that usually lives in its tissues. Without the algae, the multicolored coral turned ghostly white.

Disrupting this symbiotic relationship can stunt coral’s growth, hinder its reproduction, and leave it vulnerable to disease. Marine animals like fish, crustaceans, and reptiles depend on coral to survive. Reefs provide them a place to dwell, hunt, and hide.

Bleaching isn’t limited to the Great Barrier Reef, which, at 134,630 square miles, is one of the biggest living structures in the world. Reefs in the Seychelles, New Caledonia, Florida, and Hawaii are also suffering. And the biggest contributor to these bleaching events is the rise in ocean temperatures due to global warming.

Though coral bleaching will not stop until the climate crisis itself is addressed, politicians, scientists, and activists are scrambling to figure out shorter-term ways to save coral reefs from being destroyed.

An unlikely tool for doing so has emerged from the tech sector: 3D printing. To stop the bleaching, scientists need to better understand how coral reefs function in the wild, and 3D printing is useful because it lets them replicate coral in the lab. Previously, researchers would have to take coral out of its natural environment in order to study it.

Scientists at multiple institutions are now 3D-printing replicas of the corals that are dying off, potentially providing new homes for the algae. A team at Cambridge University and the University of California, San Diego, published a paper about their recent effort in Nature Communications in April. Lead author Daniel Wangpraseurt, PhD, a Marie Curie Postdoctoral Fellow at the University of Cambridge, tells OneZero the development is “an important step” for understanding the changes corals undergo during high-stress events like bleaching.

“At the same time, the field of 3D bioprinting is rapidly developing, primarily driven by human tissue engineering,” Wangpraseurt says. “With such rapid progress, I do not consider it unrealistic that our approach can be further developed to help in actively restoring coral reefs in the future.”

The scientists 3D-printed coral-like structures using a combination of gels mixed with cellulose, a substance found in the cell walls of plants and algae. Since cellulose is “excellent” at scattering light, it helps the 3D-printed coral attract and spread light to the algae that grows on it, explains study lead Silvia Vignolini, PhD, a lecturer in the Department of Chemistry at the University of Cambridge.

“But, like, we need to stop climate change. That’s the main thing affecting coral reefs.”

Meanwhile, two marine scientists at the University of Delaware are studying whether 3D-printing coral could be installed in the wild without disrupting local marine life. They’ve done so by examining how the damselfish, which is commonly found in reefs, interacts with them. According to a study they published in PLOS One in 2019, 3D-printed coral didn’t impact the behavior of damselfish, suggesting that it could be used to augment existing reefs.

“We are still in the early stages of testing and running experiments, but it appears that 3D-printed corals can offer the same structural complexity as a living coral and augment that necessary complexity in an area that is flattened until the reef is able to recuperate,” co-author Danielle L. Dixson, PhD, tells OneZero.

Dixson and her colleague Emily J. Ruhl, PhD, printed coral using a variety of different materials, including cornstarch and a combination that includes stainless steel, both of which are biodegradable. Structures that are biodegradable could help coral recover in their natural environment and then eventually decompose into the water, instead of creating pollution or requiring removal. Damselfish didn’t show a preference for one type of material over another, suggesting a promising future for biodegradable corals.

Reef researcher Shayle Matsuda, who studies coral symbiosis at the University of Hawaii, Mānoa, and the Hawaii Institute of Marine Biology, and wasn’t involved in either of these two projects, is excited about this research, but he also has his hesitations.

“3D-printed coral is not a replacement for coral,” he tells OneZero. While he’s interested in how 3D-printed coral can enhance laboratory research, he doesn’t think it’s “the solution for coral reef degradation.”

Matsuda wants to avoid a future in which people go on a snorkeling vacation to see coral, but everything they see has actually been artificially created in a laboratory with a 3D printer.

“This could be good. This could be helpful,” Matsuda says. “But…we need to stop climate change. That’s the main thing affecting coral reefs.”

Drew Costley is a Staff Writer at FutureHuman covering the environment, health, science and tech. Previously @ SFGate, East Bay Express, USA Today, etc.

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