3D Printed Reefs Could Help Island Nations

Globally, low islands are losing shorelines at an accelerated rate due to sea level rise, and an Australian organization has developed a 3D-printed solution that it is now proposing to the United Nations and the World Bank.

The WWF estimates that as much as 50 percent of the world's coral reefs have disappeared in the last 30 years. Some islands have experienced the loss of their fringing reefs due to blast fishing, poor fisheries management, dredging and increased seawater temperatures. Sea level rise adds extra potential for degradation of such coastlines.

Re-constructing sections of fringing reefs using traditional concrete modules requires significant logistics to import the cement and construct the modules and then deploy them.

Reef Design Lab, a not for profit design studio and think tank based in Melbourne, Australia, has developed a different approach. The organization uses a barge mounted 3D construction printer by DSHAPE in Italy. The device uses local sand to print specifically-designed reef units that are deployed to rebuild natural barrier reefs. The use of local sand means that no foreign material is added to the natural reef.

Director David Lennon acknowledges that working with the United Nations will be a longer term project for the Lab, but the technology is gaining acceptance across a range of habitats and projects. “More immediate projects relevant to ports, marinas etc are our seawall tiles and our involvement in the World Harbour Project initiated by the Sydney Institute of Marine Science,” he says. 

The World Harbour Project aims to create a network of cities focused on resilience within urbanized harbours and ports.

“Our role was to design and manufacture three different types of cement tile and send 40 of each type to researchers around the world for installation and testing,” says Lennon.

Locations participating in the trials include: Sydney, Tasmania, New Zealand, Penang, Hong Kong, Taiwan, Singapore, Israel, San Francisco, Chesapeake Bay (in the U.S.), Ireland, Plymouth, Italy, Chile and South Africa.

The tiles are square, 25cm x 25cm, and weigh around four kilograms. These initial models are sized mainly for testing purposes. “For a proper seawall enhancement project, we would use larger tiles and tiles of varying shapes and complexity depending upon target species.”

The Lab designs the shape of the structures to suit the habitat requirements of the various organisms being targeted. Location and depth are also important considerations in the success of biodiversity project.

“There is a growing trend for maintaining biodiversity in coastal areas,” says Lennon. “We are seeing the evolution of coastal engineering design, and that’s where we are involved in - providing different seawall tiles to 12 different countries.” 

The Lab has also produced Australia’s first floating artificial reefs which will soon be positioned in an estuary in South Australia. There are a lot of estuaries where people are interested in increasing biodiversity, says Lennon, who sees lots of opportunities arising from this application.