3D printed concrete ‘Innoreefs’ could help restore real coral reefs

Even if environmental factors such as ocean acidification can be addressed, our devastated coral reefs will still need help to recover. This is where a “Lego-like” system known as the 3D Innoreef is designed to come in.

Developed at Chulalongkorn University in Thailand, the 3D Innoreef consists of 3D printed concrete modules that are designed to look and function like the calcium carbonate “skeletons” of natural coral reefs.

Groups of three modules are placed on the ocean floor and connected to each other – like Lego pieces – where they continue to act as a single “shelter” for free-swimming coral larvae known as planulae. Once these larvae have established themselves in the nooks and crannies of the modules, they begin to produce calcium carbonate, essentially building a veritable reef over the concrete wall.

To give the larvae a boost, the surface of the concrete is already pre-coated with calcium phosphate, which is essential for coral growth. The strategy appears to be working well – several Innoreefs that have been installed along the coast of Thailand’s Chonburi province since 2020 have found that corals grow significantly faster than their counterparts on natural reefs, by around three to four centimeters ( 1.2 to 1.6 inches) per year.

As an added benefit, the holes and cavities built into Innoreefs provide hiding places for fish, invertebrates and other animals, encouraging them to return to the restored reefs. In addition, the modules can house sensors to monitor reef health—scientists have already adapted Innoreefs to serve as “smart stations” that monitor factors such as water temperature, pH and tidal forces.

Ongoing research will now focus on reducing the cost of the modules and making them more realistic. It should be noted that other groups are working on similar projects that involve coral-like structures that contain larvae made of terracotta clay and actual calcium carbonate.

“Although nature has been greatly destroyed, humans can still restore and recreate it with innovation,” said project leader Dr. Nantarika Chansue. “We hope that the Innovareef will be a better alternative for restoring the marine ecosystem, boosting the local economy, fishing and ecotourism.”

source: Chulalongkorn University