3D-Printed Polylactide Structures Do Not Affect the Demography of the Threatened Coral Acropora cervicornis

The development of artificial structures using emerging 3D printing technology has been proposed as a possible strategy to promote the recovery of degraded coral reef ecosystems. Current technologies allow 3D printers to faithfully replicate the morphology of coral reef attributes (e.g., substrate and coral colonies). Thus, 3D printing can be used to create artificial structures that replicate microhabitats resembling those found by reef organisms in nature. However, the use of 3D printing technology for reef conservation and restoration purposes is still in its early developmental stages. Consequently, the potential benefits or detriments of the technology on coral reef health and dynamics remain largely unexplored. In this context, there are concerns about the potential negative effects that common materials used to produce 3D structures, i.e., thermoplastic filaments, may have on reef—dwelling species. Thus, we aimed to determine whether structures made of polylactic acid (PLA) filaments have an adverse effect on the demographic performance of the coral Acropora cervicornis. We carried out a field experiment in which the survival, growth, and productivity of coral colonies growing in contact with PLA structures were compared to those of colonies growing in isolation (control), colonies growing in contact with a natural coral skeleton, and colonies in contact with structures made of ceramic. We found that none of the demographic parameters studied differed among treatments, highlighting the potential of using PLA—based structures to aid in the recovery of degraded coral reef ecosystems.