The « Biorock » technology for the preservation of coral species developed by Wolf Hilbertz and Thomas Goreau is today used on more than 20 sites in the world. The principle: a weak electric current, produced by solar panels and wind turbines, circulates in a metallic grill and produces limestone through electrolysis in the sea water. The small nurseries are then installed on a sandy bottom, a few metres deep. The coral cuttings or the debris gathered on the site are then implanted on the layer of sedimentary limestone and they reproduce. In 80% of cases, these artificial reefs survive.