Biorock artificial reef off the Gili Islands, Indonesia

Rebuilding a reef. Diving into World Oceans Day

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.The story of Biorock is a good example of how technology and human innovation are important parts of the conservation movement, especially where Earth’s oceans are concerned. More than 70 percent of our planet’s surface is covered by oceans, and those oceans contain 97 percent of Earth’s water. That’s why ocean health is a global concern. It’s also the motivation behind World Oceans Day, celebrated every June 8. We’re celebrating with this photo of a Biorock reef off the Gili Islands in Indonesia.