Humans have been trying to construct artificial coral reefs since at least the 1950s, with only marginal success. But in 1979, German scientist and inventor Wolf Hilbertz created ‘Biorock,’ also known as ‘Seacrete.’ Hilbertz found that by directing a low-voltage charge to a metal frame submerged in seawater, calcium and other minerals in the water would build up on the frame. This mineral coating is so similar to the mineral composition of natural reef substrate that it creates a good habitat for the growth of corals. After the minerals have begun to coat the surface, divers transplant coral fragments from other reefs, attaching them to the structure’s frame. These coral pieces begin to bond to the accreted mineral substrate and start to grow, typically faster than in natural environments. Eventually the reef looks and functions like a natural reef ecosystem rather than an artificial one.