Artificial reefs are increasingly deployed as coral reef restoration tools, yet material selection remains a largely unconsidered variable. Conventional materials, including concrete, steel, and anthropogenic waste, fail to support the dynamic biological and geochemical processes fundamental to healthy reef function, while contributing to embodied carbon concerns. This research presents the design, characterisation, and field evaluation of a novel calcium carbonate (CaCO₃) biocomposite, engineered to function as a living reef scaffold that supports coral recruitment while enabling bioerosion and in-situ carbonate recycling by reef organisms.
Material characterisation was conducted using powder X-ray diffraction, scanning electron microscopy, and 3D surface topography mapping, with benchmarking against earthenware ceramics and tank-grown coral. Following a nine-month field deployment, results reveal active recruitment of reef-building organisms and grazing marks by marine bioeroders, indicating meaningful ecological integration. The material's versatility was further demonstrated through successful paste-based 3D printing, enabling complex surface micro-topographies known to influence larval settlement and species recruitment.
These findings reframe material selection as a critical ecological variable in artificial reef design and offer a replicable, environmentally conscious framework for reef restoration across Australia's temperate and tropical marine environments.