Environment

3D-printed clay tiles designed to restore coral reefs

3D-printed clay tiles designed...
The reef tiles were deposited last month at three test sites in Hong Kong waters
The reef tiles were deposited last month at three test sites in Hong Kong waters
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The reef tiles are robotically 3D-printed out of conventional terracotta clay, which is then kiln-fired at a temperature of 1,125 ºC (2,057 ºF)
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The reef tiles are robotically 3D-printed out of conventional terracotta clay, which is then kiln-fired at a temperature of 1,125 ºC (2,057 ºF)
The idea behind the tiles is that they be placed in interlocked groups on the ocean floor, providing a reef-like structure upon which coral will grow
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The idea behind the tiles is that they be placed in interlocked groups on the ocean floor, providing a reef-like structure upon which coral will grow
The reef tiles have been seeded with fragments of Acropora, Platygyra and Pavona coral
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The reef tiles have been seeded with fragments of Acropora, Platygyra and Pavona coral
The reef tiles were deposited last month at three test sites in Hong Kong waters
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The reef tiles were deposited last month at three test sites in Hong Kong waters
The pattern on the tiles replicates that of natural coral reefs
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The pattern on the tiles replicates that of natural coral reefs
A batch of the reef tiles, ready to go
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A batch of the reef tiles, ready to go
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It's no secret that the world's coral reefs are dying off at an alarming rate. In order to encourage the growth of the coral that remains, scientists from the University of Hong Kong have developed what are known as "reef tiles."

The idea behind the tiles is that they be placed in interlocked groups on the ocean floor, providing a reef-like structure upon which coral will grow. Users can both "seed" the tiles with coral fragments, and wait for coral polyps to naturally colonize the tiles as the organisms are carried past on ocean currents.

Measuring 60 cm (23.6 in) across, the tiles are robotically 3D-printed out of conventional terracotta clay, which is then kiln-fired at a temperature of 1,125 ºC (2,057 ºF).

A batch of the reef tiles, ready to go
A batch of the reef tiles, ready to go

According to the scientists, clay is much more eco-friendly than concrete or steel, which have previously been used in other groups' reef-building projects. Not only does the production of the latter two substances produce greenhouse gas emissions, but the materials themselves can also leach toxic substances into the ocean water.

In a pilot project, 128 of the clay tiles were seeded with three types of native coral, then deposited in three sites within Hong Kong's Hoi Ha Wan Marine Park. The park is currently home to over three quarters of the reef-building corals in Hong Kong waters, although a combination of habitat destruction and coral bleaching has led to a reduction in coral numbers over recent years.

The tiles will be monitored over the next year and a half, to see if they can help restore the reefs.

Source: University of Hong Kong

View gallery - 6 images
3 comments
paul314
I know 3D printing is really cool, but those kinda look as if a simple mold would have done the same job faster and cheaper.
Sean Reynolds
When people do things like this then get publicity they need a go fund me page so that we can just chip in 5$ to their efforts. It could mean millions of dollars for them!
Karmudjun
Ben - I liked the line "clay is much more eco-friendly than concrete or steel, which .... production of the latter two substances produce greenhouse gas emissions" as if the fact the tiles are "kiln-fired at a temperature of 1,125 ºC" doesn't produce greenhouse gas emissions.

Not really trying to be difficult, but if Scientists want to make comparisons - and I don't want to search the University of Hong Kong to see if such a comparison was made or the difference in Carbon footprint. Instead I want to thank you for the article and I just wonder how much of a carbon savings results. Clearly the contamination from heavy metals or machining oils can be avoided by using kiln fired tiles - so Thanks Ben. Maybe these informative blurbs from the University will add more facts although I did like the visuals of coral base being placed.