November, 12, 2006 - 05:08AM


There are over 3,500 marine species living in the reefs and seas of Indonesia. In comparison to the Great Barrier Reef (1,500 species) and Red Sea (600 species),Indonesian’s coral reefs are the global center of marine biodiversity.

With 17,502 islands and 85,700 sq/km of coral reef (14% of the whole world coral reef), Indonesia hold the world’s richest variety of coral with 450 species.

It is one of the Indonesian’s greatest assets.

Unfortunately, only 6% of these reefs are healthy; Destruction comes mainly from human activity: dynamite and cyanide fishing, pollution, global warming, over exploitation and environmentally-unfriendly tourism, and more…

This degradation results in huge economic and cultural loss. Economic gain does not offset loss and destruction.

Damaged coral reefs take years to recover naturally. Despite conservation efforts now to address these problems, natural regeneration under existing efforts is inadequate, in part due to increasing global stresses.

In Krang Lestari Pemuteran (Protected Coral) project, hotels, dive shops, village fisher folk, scientists and conservationists did unite to, protect and restore coral reefs, increase fishery resources and develop sustainable economy for local fisherman communities, which are benefiting both tourism and local economy.

A compelling element of this “pilot project” is the interactive involvement of traditional community, government and private enterprise. Its goal is to enhance tourism through conservation and protection, while contributing economic and benefit.

With this effort, a radical new approach to reef restoration was undertaken: “Mineral Accretion” literally grows reefs.

This unique reef system is the brain child of scientists Professor Wolf Hilbertz and Doctor Thomas Goreau. Artificial reef construction by means of mineral accretion, also known as “third generation” artificial reef systems, is a novel technology which uses electricity to “grow” limestone rock on artificial frames and increase growth rates of corals and other reef organisms. These resulting coral and fish nurseries have reestablished a devastated marine ecosystem in a very short time.

Two NGOs (Yayasan Karang Lestari Pemuteran and Global Reef Alliance) are responsible for this project. They are dynamic and complementary.

The award-winning community-based coral restoration project in Pemuteran Bali is becoming one of the world’s major educational and experimental facilities to further coral reef regeneration, coastal protection and socialization of sustainable management of coral reefs ecosystems for conservation and tourism development.




SITUATION ON Gili Trawangan

Gili Trawangan is a beautiful Indonesian island and a popular destination for tourists and divers. Unfortunately a large proportion of the fringing coral reef has been damaged by global warming, natural weather action (storms) and destructive fishing practice.

In Gili trawangan, the Gili Eco Trust is a non profit organization concerned with cleaning the island and protecting the coral reefs from destructive fishing methods. Each diver in Gili trawangan has to pay a reef tax of 30,000 Rupiah (=US$ 3).

This money is collected and reinvested to collect and manage the rubbish problem on the island, to pay the fisherman a salary in exchange of no dynamite fishing any more, and control the application of the rules.

Since 2004 a biorock structure is already installed in Gili Trawangan by Villa Ombak Hotel and had involved many Indonesians and westerners.

A new artificial reef extends the possibilities for the island and the local population to learn how to protect their environment and see the benefits of their actions. The new project is designed to involve more people and to spread the information resulting from the structure and its benefits.

The methods pioneered in Pemuteran have proven successful where other strategies have shown little result in restoring reefs and fisheries. This project has demonstrated that restoring coral growth can bring fish back. Local fishermen see schools of many kinds of fish attracted to the coral nurseries, as they pass over them en route to their barren fishing grounds miles off shore.

Biorock project in Gili is a new initiative for the local community, helping them to protect their coral reef and understand the importance of maintaining a healthy, vibrant marine ecosystem for future generations.




  • Build additional Biorock structures to grow other artificial reefs in Gili Trawangan.
  • Create a new coral reef on Gili Trawangan involving the local population.
  • Teach the local population how to protect their environment and show them the benefits of reef protection and regeneration for them and their children.
  • The structure is also designed as a teaching material for scuba diving. Many specialties can be taught using the structure including underwater photography, fish identification, naturalist and peak performance buoyancy.
  • Involve dive instructors and dive masters from the whole island. Teach students to respect marine life with a visit to the structure during a scuba diving course or a fun dive.
  • Make the following studies: growth rate; survival rate; document the different species of fish settled on the structure; visiting fish numbers and the effect of the “accretion” on the different species of coral…
  • Build a Web Site describing the project and following the regeneration of the reef.
  • Get tourists actively involved through contribution to the building, financing and ongoing growth of the structure.
  • Organize Biorock workshop in Gili Trawangan with Thomas Goreau, Wolf Hilbertz, Indonesian universities, western students, dive instructors and others.
  • The hope and plan is to extend this process to the entire island. To expand the reef restoration by building more structures and extending the existing structure deeper and wilder.


The project is to build a biorock structure in Gili Trawangan to create a coral reef and generate marine life around it.
Two electrodes supplied with low voltage direct current are submerged in sea water. Electrolytic reactions at the cathode cause minerals naturally present in sea water to build up. At the same time a wide range of organisms on or near the growing substrate are affected by electrochemically-changed conditions, shifting their growth rate.
Stray or loose living corals are carefully collected from nearby destroyed reefs and transplanted onto the structures. They are attached with wires or wedged between steel bars. These coral bits are quickly cemented into place by growing minerals forming over the structure’s surface. The reefs are electrically charged to grow.
The reef restoration project is only one phase of a bigger overall plan. The timescale of the project is many years as coral grows slowly and releases spores only once a year to repopulate other areas. However the technology ensures that the coral structures inside the project will stay healthy even in times of stress. One of the many benefits of the reef restoration project is that reef fish, schooling fish and many other marine life forms gravitate to the area. It is a fish nursery as well as a coral nursery and therefore will become an excellent snorkeling and dive site.
The location of the new artificial reef in Gili Trawangan is on the beach, 500 metres north of the harbor, in water 6-8 metres deep. The power supply comes from Trawangan Dive. The structure is made of steel bars 10 meters in length and 8 millimeters diameter. It has a tunnel 1,5 meters high, 10 meters long and 2,5 meters wide. The coral is tight up at the intersection of the bars, mostly on the top of the structure. Some steel mesh (chicken wire) is attached to some parts of the structure to provide fish habitats.
The first structure will be the beginning of the project and lots of smaller structure will be connected to the first one.




Description Price Quantity Total
steel bars (10,5 meters, 8 mm diameter) 25.000 140 3.500.000
Fencing steel (1*0,90 meters) 6.000 70 420.000
steel wires (6kg) 60.000 1 60.000
hose pipe (1 meter*3 centimeters diameter) 50.000 2 100.000
sand paper 20.000 1 20.000
titanium (1*0,90 meters) 2.000.000 1 2.000.000
power supply( 6-12 volts generator) 650.000 1 650.000
cables supreme (100 meters length) 891.000 1 891.000
cables focus (300 meters length) 2.304.000 1 2.304.000
Epoxy hardener and resin 30.000 2 60.000
TOTAL 10.005.000



Dr Thomas J Goreau:
President of Global Coral Reef Alliance
Website :
Email :
Tel : 617-864-4226, 617-864-0433

Dr Wolf Hilbertz:
co-inventor of Biorock process.
Email :

Delphine Robbe:
Master Scuba Diver Trainer at Big bubble dive.
Email :
Tel : +62 (0) 813 39 600 553

Foued Kaddachi:
Open Water Scuba Instructor, underwater Photographer at Blue Marlin Dive
Email :
Tel : +62 (0) 813 39 585 091

Laurent Lavoye:
Course Director at Trawangan Dive
Email :
Tel : +62 (0) 812 38 54 178


The First structure was placed in the water on the 19th of July 2006 with a great deal of help from dive shop staff and the local community.
The Fourth Biorok workshop is planned to be held on 13-20 November 2006, Gili trawangan, Lombok Indonesia.
Participants in this year’s workshop will contribute to a documentary being filmed by a joint French-German TV production crew.