A team of computational designers at UNSW Sydney’s School of Built Environment is creating 3D printed reef structures called BioShelters to support the recovery of oyster populations in Blackwattle Bay and surrounding areas of Sydney Harbour. Funded by the government-owned corporation Landcom and the NSW Government the project applies advanced computational methods from architecture to design and fabricate environmentally focused coastal infrastructure.
Design and Ecological Impact
Each BioShelter is made from a 3D printed recycled plastic mould filled with a concrete mixture incorporating crushed oyster shells. Measuring roughly six metres long, two metres wide, and 90 centimetres high, each structure is divided into 25 panels. Recently, the BioShelters were installed at the Sydney Fish Market site in Glebe, an area where urban development has heavily reduced natural habitats.
“Just as there is a housing crisis in Sydney for humans, there is one for sea creatures like oysters,” says Professor M. Hank Haeusler, Director of the ARC Centre for Next-Gen Architectural Manufacturing at UNSW, who leads the BioShelters project. “What this project aims to do is create new artificial habitats that are as close to nature as possible.”
Oysters are vital to marine ecosystems, filtering up to 100 litres of water per day, providing food for fish, and creating habitats for invertebrate species. Since oysters colonise by growing on other oyster shells, the BioShelters use reclaimed oyster shells in the concrete to encourage natural colonisation.
Unlike traditional flat seawalls, which cover over 50% of Sydney Harbour’s shoreline and lack natural crevices, BioShelters are site-specific, 3D printed structures designed to support diverse marine life. Using algorithms and robotic fabrication, the team translates marine biology data into forms that restore oysters while also benefiting fish, seaweed, kelp, and other species.
From Prototype to Future Applications
The BioShelters project began in 2016 through collaboration between architects, computational designers, marine biologists, and engineers. Previous research identified the environmental needs of Sydney rock oysters, native hairy mussels, and certain kelp species.
Using this data, the team created digital models and 3D printed prototypes. A full-scale prototype installed under the Anzac Bridge in 2020 successfully attracted oysters, seaweed, kelp, and small fish within six months, confirming the concept. “The success of the proof-of-concept trial led to the commission from the new Sydney Fish Market to install and design the permanent feature,” says Prof. Haeusler.
Future plans include refining the fabrication process to print directly in concrete and enabling marine biologists to submit site-specific designs for automated production. The modular structures could be adapted for harbours worldwide and potentially extended to create artificial habitats for terrestrial species.
“We have already started a conversation for a larger installation, revitalising seawalls across Sydney Harbour,” Prof. Haeusler says. “And there’s potential to take the principles to design and generate similar artificial habitats for other species on land such as mammals, birds, bats and rodents that also need homes.”
Efforts to Protect Marine Ecosystems
Across the globe, researchers are leveraging 3D printing to restore and protect marine ecosystems, creating structures that support biodiversity, reduce erosion, and improve water quality.
In May, a modular concrete tile system developed at Florida International University (FIU) was deployed to test how 3D printed surfaces can enhance marine biodiversity, reduce shoreline erosion, and improve urban water quality. Known as BIOCAP—short for Biodiversity Improvement by Optimizing Coastal Adaptation and Performance—the system is scheduled for pilot installation in 2025 at Morningside Park, a public site on Miami’s Biscayne Bay.
The project is led by Sara Pezeshk, a doctoral candidate in FIU’s College of Architecture and a member of CREST CAChE, the university’s Center for Aquatic Chemistry and Environment. Her peer-reviewed paper outlines a hybrid infrastructure strategy that combines additive manufacturing, ecological design, and responsive material systems. Funding is provided by the National Science Foundation and the Environmental Protection Agency.
Earlier, in 2020, a team of architects and scientists at Hong Kong University (HKU) developed a new method of repairing a coral reef in the nearby Hoi Ha Wan Marine Park. The researchers designed and 3D printed 128 hexagonal clay tiles with complex structures that were custom-made to encourage coral attachment, and deployed them in three sites around the bay. HKU’s artificial reef will be monitored for the next 18 months to ensure its survival, but the team hopes that it could represent an effective method of preventing deterioration of coral reefs across the region.
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Featured image shows The BioShelters team during the installation process at Blackwattle Bay. Photo via UNSW Sydney
