frist 3d printed coral reefs

on 2012 experts from international consortium Reef Arabla sank two 3D - pitted  coral reefs off the  coast  of bahrain. Weighting some 1,00lb (500kg) each the  artifcial   reefs  are made from a non- toxic patented sandstone- like material designed  to be more attractive to coral larvae and other  marine creatures. And  unlike traditional concrete  atficial  reefs their  3D counterparts are PH neutral.