After red tide algal blooms killed off 90% of local coral species at Hong Kong’s Hoi Ha Wan Marine Park in 2015 and 2016, researchers at the University of Hong Kong 3D-printed terracotta tiles to try to save the remaining coral and save the reef. The 128 tiles were designed using an algorithm that printed biomimetic patterns and allowed space to attach 400 fragments of at-risk Acropora, Pavona, and Platygyra “brain” coral. Two years later, the coral is thriving with a 98% survival rate and surprisingly fast growth. The reef is easy to customize and expand, and the versatile design can be changed to accommodate other environments such as mangroves, or serve as a scaffold for oysters. Unlike concrete, which is used in other reef restorations, the slightly acidic terracotta clay is similar to the calcium carbonate found in natural reefs. Over time, it’s expected to wear away, leaving healthy coral.
3D printed coral reef