Biorock Reef

Biorock technology was originally developed by marine scientists Thomas Goreau and Wolf Hilbertz. A low-voltage direct current is run through the steel. This electricity interacts with the minerals in the seawater and causes solid limestone to grow on the structure. It draws on the principles of electrolysis, where the electric current causes a chemical reaction to occur which wouldn’t have otherwise.

Healing space

Eventually, the limestone solidifies.

It’s the same thing that makes up [marine] skeletons. And it’s a perfect breeding ground for aquatic life.

It’s speeding up the normal reaction of coral growth. Corals on the biorocks survive more than any other.

When divers see injured coral, they move it to one of these structures to rehabilitate. The coral heals some 20 times faster, and has up to 50 times more chance of survival. The rehabilitated coral can often be astoundingly brilliant in colour and densely branched. Once healed, it is returned to the open sea.

(Credit: Gili Eco Trust)

(Credit: Gili Eco Trust)

Protecting effect

The biorocks – shaped like giant steel manta rays, pyramids, planes, dolphins, whale sharks, lizards and turtles – are helping to stave off these adverse effects.

And it’s not just coral that improves: the biorocks have helped the fish populations as well, particularly lobsters and juvenile fish who shelter in the structures.

They have also helped turn the tide when it comes to severely eroding beaches. Slowing the onslaught of fast waves, biorocks lead sand to be deposited, rather than eroded, at the shoreline. This has seen certain parts of the beach grow some 15 metres in a few years.

And, they’ve proven themselves resistant to damage from natural disasters, such as the Asian Tsunami of 2004, as their open frameworks allow large waves to pass through.

While there is no limit to the size or shape of the structures – they could be hundreds of miles long if funding allowed – there is a limit when it comes to powering them…You can’t have them way out to sea because you need electricity.

The team has experimented with powering biorocks using solar energy from a solar panel on a barge above the structure. The only problem? The panels are often stolen.


Marine Ecosystem Restoration Talk: By Dr. Tom Goreau at UN Framework Convention on Climate Change, Paris COP 21 December 2015

Electrical Stimulation Greatly Increases Settlement, Growth, Survival, and Stress Resistance of Marine Organisms

Increasing stress from global warming, sea level rise, acidification, sedimentation, pollution, and unsustainable practices have degraded the most critical coastal ecosystems including coral reefs, oyster reefs, and salt marshes.

Conventional restoration methods work only under perfect condi- tions, but fail nearly completely when the water becomes too hot or water quality deteriorates. New methods are needed to greatly increase settlement, growth, survival, and resistance to envi- ronmental stress of keystone marine organisms in order to maintain critical coastal ecosystem functions including shore protection, fisheries, and biodiversity.

Electrolysis methods have been applied to marine ecosystem restoration since 1976, with spectacular results (Figures 1(a)-(c)).

This paper provides the first overall review of the data. Low-voltage direct current trickle charges are found to increase the settlement of corals 25.86 times higher than uncharged control sites, to increase the mean growth rates of reef-building corals, soft corals, oysters, and salt marsh grass— an average of 3.17 times faster than controls (ranging from 2 to 10 times depending on species and conditions), and to increase the survival of electrically charged marine organisms—an aver- age of 3.47 times greater than controls, with the biggest increases under the most severe envi- ronmental stresses. These results are caused by the fundamental biophysical stimulation of natu- ral biochemical energy production pathways, used by all organisms, provided by electrical stimu- lation under the right conditions.

This paper reviews for the first time all published results from properly designed, installed, and maintained projects, and contrasts them with those that do not meet these criteria.

Thomas J. Goreau

Global Coral Reef Alliance, Cambridge, USA Email: [email protected]
Received 23 May 2014; revised 26 June 2014; accepted 5 July 2014
Copyright © 2014 by author and Scientific Research Publishing Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY).


There are currently 63 biorock structures projects around Gili Trawangan, Gili Meno and Gili Air at this present time, their aim to create a coral reef and generate marine life around it.

This is a huge amount of work, some are shaped like Starfish, some ar swimthroughs, theres even an aeroplane and a Manta shaped one.

A little technical stuff because it is actually really easy.

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. 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 locations of the new artificial reefs on Gili Trawangan start in front of Villa Ombak hotel and are positioned all along the beach front up untill the north of the island. They are all in water 8-16 metres deep, purposely made so snorkellers can also see them clearly, with structures made of steel bars, all vary in shape and size from tunnels to domes and swim throughs.

Go and have a look !