The local fishermen looked on skeptically. From the deck of a small motorboat, scuba divers grabbed odd chunks of ceramic – which could be described as rocky brains stuck on stumpy stilts – and plunged into the aquamarine waters. The dive team assembled the pieces as a few triggerfish circled around to investigate the commotion. After just two air tanks (about an hour each), they had locked all of the items together into the final product: an artificial coral reef.
The 3D-printed reef, installed at Summer Island Maldives resort earlier this month, is the first of its kind on any of the 1,200 islands of the Maldives. Each of the artificial reef’s ceramic components was 3D printed with a custom design and then fitted with coral fragments that developers hope will grow across the entire structure.
3D printers have become faster, cheaper, and more accurate in the past decade, allowing enthusiasts to develop neat trinkets such as toothpaste squeezers and custom pasta makers. Australian entrepreneur Alex Goad had a more ambitious application: 3D printing coral reefs. He formed the not-for-profit Reef Design Labs (RDL) to apply the flexibility of 3D prints to coral restoration research.
“I started Reef Design Labs to support marine research, that’s the main thing we do,” Goad told Mongabay. “I was interested in ceramic and how it could be used as an ideal material for coral nurseries. So we gave it a go.”
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[The 3D-printed reefs] have all these contours and shapes that mimic the natural reefs, so that corals can easily attach themselves…which we can’t do just building regular concrete structures.
Aminath Shauna, spokesperson, Summer Island Maldives
A customizable approach to reef restoration
RDL calls its patented technique for 3D-printed coral formation Modular Artificial Reef Structure, or MARS. Instead of using steel or concrete, popular substrates for artificial reefs, RDL prints hollow blocks of ceramic, which can be molded into complex shapes, and fills them with concrete for stability. Divers bring these blocks underwater and fit them together like LEGOs to form a cohesive and resilient structure.
3D printing artificial reef structures may sound like a gimmick to draw attention, but Goad suggests several benefits of a custom-design reef mold. Coral begins its life cycle as drifting larvae that search for an unexposed place buffered from predators and water currents.
3D printing can replicate the intricate structure of existing reefs needed to foster new coral growth. Within minutes, the small alcoves and overhangs of the Maldivian MARS also began attracting curious fish; it may someday provide shelter to crustaceans, sponges and anemones to form a marine community.
“[Reef Design Labs] actually designed the structure based on the corals that are most widely growing in the Maldives,” said Aminath Shauna, a native Maldivian and spokesperson for Summer Island Maldives. “[The 3D-printed reefs] have all these contours and shapes that mimic the natural reefs, so that corals can easily attach themselves…which we can’t do just building regular concrete structures.”
Goad was not the first to construct 3D-printed reefs; another Australian, James Gardiner, paired up with Sustainable Oceans International (SOI) to sink blocks of sandstone amongst sections of a damaged reef system in the Persian Gulf in 2012.
The advantage provided by MARS is convenient installation. Rather than using barges to transport beefy chunks of concrete out to sea, divers can slot a customizable set of MARS pieces together by hand to form a sturdy skeleton in shapes inspired by the native coral community.
Reef Design Labs has applied its technology to support other marine life as well. n June 2017, RDL supplied concrete reef units for Australia’s largest shellfish restoration, for which researchers sank more than 17,000 tonnes (18,740 US tons) of limestone near Yorke Peninsula and then released tiny oyster larvae to settle on the new structures.
In April 2016, the lab teamed up with Riot Games to design marine sculptures, including a character from a popular online video game, as appealing hideouts for fish communities. The lab is now working with Volvo and Sydney Institute of Marine Science to create oyster habitat on seawalls. Each project’s design and implementation solicits input from marine biologists, who monitor the structures to assess which methods yield the most permanent habitats for corals and other reef organisms.
The materials and methods of installation for an artificial reef must be carefully chosen and prepared, or the structure may do more harm than good for the marine environment. 3D printing also requires specialized equipment and expertise, and there is a ceiling to how much custom reef design can be scaled up. Goad acknowledges there are limitations to the practice.
“People assume that 3D printing is going to be some magic thing that is going to save the coral reefs – obviously not. This is to be used for small coral nurseries. I was interested in how MARS could help this cause: a permanent structure that had complexity and would allow other reef species [besides corals] to have a home.”
MARS acts as a platform for targeted research on optimal coral farming methods. Prints can be tailored to specific experiments, for instance testing how different techniques of attaching coral fragments affect growth. Such research may help scientists better understand and adjust to the threats faced by coral reefs.
This story was published with permission from Mongabay.com. Read the full story.
