Your Magazine Guide to Gili Islands

Biorocks are artificial coral reefs and are now one of the GiliĀ Islands most unique underwater features!



In 2004, the first biorocks were installed in an effort to restore the damaged coral reefs around the islands and recover the natural habitat of the resident sea life. To date, Gili Eco Trust, an NGO based on Gili Trawangan, has planted more than 150 structures!

So how do you recreate a natural coral environment? Stray or loose-living corals are carefully collected from nearby damaged reefs and transplanted onto artificial structures.

The corals are attached with wires or wedged between steel bars, which are then quickly cemented into place by growing minerals, forming over the surface of the structure. A low voltage of direct current is put through the coral and this encourages dissolved minerals in the sea water to accrete onto the steel structures, forming a solid layer of limestone which is the same composition of beautiful reef-building hard corals! With this energy boost, corals can focus on growing bigger, faster and stronger and have now been proven to be more resilient to climate change and warming oceans.

The Biorocks are solid structures for hard reef-building corals to grow on and they foster many new corals and attract a vast array of reef fish, schooling fish, and many other marine life forms that gravitate to the area. It is a fish nursery as well as a coral nursery. The structures also create valuable wave breakers to protect the beaches from erosion and are making for incredible
dive sites.

Eco-tourists are encouraged by the Gili Eco Trust to dive or snorkel around the structures and learn about how to boost natural coral growth up to six times faster.