You may know that ceramic tile can be used just about anywhere inside and outside your home or business, but even we were surprised to learn that tiles are now flourishing on the seafloor as a solution for coral restoration.
Mass Destruction of Coral Reefs Calls for Innovative Problem-Solving
Hong Kong’s Hoi Ha Wan Marine Park is home to 60 species of coral reefs as well as 120 fish species, making it a hub of biodiversity.
However, this coral population has recently been put at increasing risk as a result of bioerosion (gradual deterioration), coral bleaching, and mass mortality events. For example, a super typhoon disintegrated nearly 80% of Hoi Ha Wan Bay’s coral reefs in 2018.
Natural regeneration of this destroyed coral could take decades according to marine scientists, since sand can damage the coral reefs and they can’t attach to the seafloor by themselves.
Restoring the coral reefs would require some additional support, for which a team of marine scientists and architects at the University of Hong Kong (HKU) turned to tiles.
Reef Tiles: A New Type of Tile — and a New Conservation Method
The team realized they needed to create a structurally complex design so that dislodged bits of coral would be able to attach to the surface. 3D printed “reef tiles” were designed for these bits of coral that couldn’t survive on their own.
The team created 128 hexagonal tiles measuring 600 mm across through robotic 3D clay printing and then fired them at 1125 degrees Celsius, becoming the first in the world to create 3D-printed clay tiles. The design of the tiles mimics the appearance of Platygyra Brain Worm Coral and prevents sedimentation, one of coral’s biggest threats.
While the team considered using concrete and metal at first, they landed on terracotta clay because it’s more environmentally friendly. “Basically, clay is just soil in the end,” Christian Lange, an Associate Professor at the HKU Faculty of Architecture, pointed out.
The tiles were seeded with three different local species of coral fragments (Acropora, Platygyra, and Pavona) to create a diverse marine habitat and then planted in three different sites in the Marine Park in July of 2020.
Monitoring will be ongoing for the next one and a half years, but the scientists have already observed that 100% of the coral on the tiles was still thriving after two months. They are hopeful that the tiles will help restore Hong Kong’s degraded coral reefs and, eventually, contribute to coral conservation worldwide.
Watch the video below for an even closer look at the reef tiles in action.