Biorock reef restoration. Sign declaring the Pemuteran Biorock Coral Restoration Area, Pemuteran, Bali, Indonesia, as a no-fishing zone. The Biorock process was developed by Thomas Goreau and Wolf Hilbertz in the 1970's. Electricity is used to promote the deposition of calcium carbonate on the surface of a structure giving hard corals a base to bond to. The process is thought to accelerate coral growth by up to four times - however, it has been suggested that simple wire meshes are just as effective. The resulting 'reef' of hard coral soon attracts other inhabitants and the process has been touted as a way to rehabilitate reefs in all tropical areas. Photographed in Pemuteran, Bali, Indonesia.