3D-printing improves the development of artificial reefs

If they succeed in the coming years in luring not only fish but also baby coral polyps, they can grow into new reefs and reestablish some of the most important habitats on Earth.

3D printing contributed to wildlife conservation in the early 2000s. Dudley, a duck who lived in British Columbia and lost a fight with a chicken, was given a prosthetic leg. A bald eagle whose beak had been partially shot off received a 3D-printed bill that looks like the real thing. It was only a matter of time before someone figured out how to recreate a reef structure.

The first 3D reef was sunk off Bahrain in the Persian Gulf in 2012. However, the process is way more complex than making bird beaks and duck legs. Designing 3D reefs has been compared to designing a city for very specific inhabitants. Reef sections can weigh up to 2.5 tons each.

Artificial reefs are not new. They have been made of sunken shipwrecks, plastic, concrete blocks, old tires, and old cars—all heaped onto the ocean floor in hopes that fish and other marine life will come to call them home.

But many of these artificial reefs fail because they don’t really fit in with their surroundings. A 3D-printed reef, on the other hand, recreates nooks and crannies, protective space for fish, passageways, doors, and angles that cast shade or light and enable fish to avoid predators or feed.

The Dutch maritime firm Boskalis, which is working on a restoration effort for Monaco in partnership with the Prince Albert II of Monaco Foundation, printed six 3D reef structures to be submerged in the Monaco Larvotto Reserve. Each reef is made of dolomite sand, weighs 2.5 tons, and measures two meters in diameter and slightly more than one meter in height. Each reef took 13 hours to print.

Astrid Kramer and Jamie Lescinski, both company senior engineers, said in an interview that the 3D reefs will be monitored for two years, to see how much of the marine life that occupied the natural reef returns. Size and dimensions of the crevices affect which fish species will show up.

In the Caribbean, Fabien Cousteau, grandson of the late ocean explorer Jacques Cousteau, began a 3D-printed reef project in January in Bonaire, where he is working with the Harbour Village Beach Club. Cousteau began diving in the Caribbean as a four-year-old and has watched reefs die off, transforming from colorful, bountiful undersea gardens to virtual deserts.

“There is no silver bullet with coral restoration,” he warns. “You are talking about a very complex environment, a complex animal with a lot of variations with each subspecies. All of this is an experiment. In the short term, we’ve seen a lot of positive momentum with certain species of coral. But remember, this is a drop in the bucket in a very, very large ocean.”