Can We 3D-Print Our Way Out of a Coral Crisis?

Coral reefs cover only about 1% of the ocean floor but support nearly a quarter of all marine species. Frighteningly, over 50% of marine coral has vanished since the 1950s due to bleaching from warmer water temperatures, ocean acidification, as well as physical destruction from human coastal activity and storms. Fortunately, marine scientists and engineers are utilizing an unexpected approach: fabricating entire new ecosystems with 3D printing technology.

Although corals undergo natural recovery, this process is extremely slow; some species of coral only grow a few inches per year. This issue is exacerbated by frequent bleaching events, killing coral before it gets the chance to even begin growing. At the rate reefs are degrading, relying on the coral's natural growth isn't really an option, so this is where the 3D printing comes in.

The core principles of engineering reefs with 3D printing is surprisingly straightforward. Coral tends to grow best on specific, complex surfaces filled with cracks, crevices, holes, and various textures. 3D printing allows scientists to replicate such intricacies in ways previous artificial reefs couldn't, opening up the doors to effective coral growth.

It starts with a quick 3D scan of real reef structures, which are then used as models in designing artificial surfaces. An artificial reef from Australia looks far different from one in the Caribbean because each 3D-printed structure is specifically designed for a certain environment to be able to effectively support native coral and wildlife. The materials used to create artificial reefs are also critically important because coral is a highly sensitive organism that requires extremely specific conditions to prosper, so scientists opt for calcium carbonate ceramics or special concrete that mimic natural reef substrates. Finally, the structures are deployed in oceans worldwide and then, slowly but surely, coral begins to colonize them.

Results from early deployments in Australia, the Maldives, and the Persian Gulf are encouraging as coral reefs show growth and fish populations increase, but it is still important to realize this technology, although promising, isn't truly a long term solution to the coral crisis; it's simply buying us time. To effectively heal the reefs, individuals need to do their part to keep our marine ecosystems intact.