Biorock project

Biorocks in Gili

The Gili islans are uniqe for the amount of Biorocks around the here.

The Biorock technology is a novel technique to create artificial coral reefs, by building a steel structure and putting a low voltage of direct current through it when sunk in the ocean.

Reef gardeners and biorock students attach alive coral onto the structures.

Due to the low voltage current and resulting electrolytic reaction a stable substrate is formed of calcium carbonate around the metal, providing a sturdy surface for corals to cement to.

This low voltage also promotes the corals grow faster and stronger than on natural reefs.

Doing this, Gili Eco Trust restores the beautiful coral reefs around Gili Trawangan in a short period of time.

They have proven to be more resilient than natural reefs in previous bleaching.

More than 120 structures are placed in the waters around the Gili Islands, fostering a lot of new corals and a vast array of fish life.

Our coral reefs are endangered by many different factors, both naturally and caused by human influence. World wide about 10% of all coral reefs have been destroyed, while 60% is threatened by human interaction. Due to the biorock technology, more corals will survive these threats, sustaining the life underwater and providing oxygen.

The Gili Islands, whilst now safe from destructive fishing methods such as dynamite and cyanide fishing, still are battling with many threats that affect our beautiful marine ecosystem.

Anchors, although widely unaccepted and illegal in Gilis, are still used for snorkel boats in certain parts of the islands. It is very apparent in these areas the destruction caused underwater.


Whilst all reefs including the Biorock reefs were at least partially bleached, studies carried out during the 2016 Il Nino event on corals transplanted onto Biorocks had a slower rate of bleaching than on natural reefs, and also when the sea cooled back down they recovered much quicker.

With events such as these climate variations of 2016 increasing in frequency and severity, it is very important to keep up the maintenance of the Biorock structures to protect our reefs from further damage.


We run a two week intensive reef restoration course on Gili Trawangan.

During the course you learn extensive marine ecology, substrate identification and complete training for the Reef Check Eco Diver.

Assessing the health of natural reefs around the Gili Islands using transect surveys and collecting data to complement long term data on reef health.


The second week consists of learning the basics of Biorock technology, designing and creating your own Biorock structure, implementing its sinking and transplanting broken fragments of coral onto it.



PADI Advanced open water (or equivalent)
Competent buoyancy skills
Whilst a marine scientific background is not necessary, a passion for ocean conservation and preservation is encouraged!

Included in course:

  • All dive equipment, protective gear, mesh bags, gloves.
  • PADI Speciality – Introduction to Biorock Process
  • Reef Check – Eco Diver qualification

Dates of next course:

29 Jan – 10 Feb 2018
12 Mar – 24 Mar 2018
16 Apr – 28 Apr 2018
18 Jun – 30 Jun 2018
03 Sep – 15 Sep 2018
08 Oct – 20 Oct 2018
12 Nov – 24 Nov 2018


Have fun and be safe!