Elsewhere, new marine habitats are being created with 3d printing and by using specially moulded concrete in bigger infrastructure. at this danish wind farm, stone and 3d printed reefs have been placed on the sea floor. the advantage to this is you can take all of the best qualities of a natural reef and you can exaggerate them, completely. algae, other organisms, need a hard substrate, a hard surface to attach themselves to so you can maximise surface, you can 3d print the structures so that they have passageways and hollows. i mean, literally moments after they were placed on the sea floor, ...