The Biorock Anti-Wave Reefs and Beach Regeneration

A Biorock project was started in 2015 to reverse severe beach erosion which had left the island almost without a beach.

Damage like this is happening worldwide due to rising sea levels. Within just a few short years there were areas of Gangga Island with barely any beach at all. The island is affected by the Australian and Indo-Chinese Monsoons and by late 2015 much of the sand had been washed away leaving a beach cliff almost 1.5 metres high rather than a stretch of pristine white sand. Something had to be done.

The decision was made to use a method known as Biorock Anti-Wave reefs, which had been seen to work incredibly well in other areas of Indonesia such as Pemuteran in the north west of Bali where they saw a 99% regeneration of the beaches after creating Biorock reefs. Biorock reefs are incredibly simple structures made from wire filled with rock. They are designed to dissipate wave energy before it hits the beach rather than deflect it. The Biorock reef allows the waves to pass through and reach the beach but disperses the energy of the wave in an even fashion which weakens the wave reducing the effect of the wave on the sand on the shore-break. The Bioreefs also have a very small electric charge passing through them to prevent rusting and to also encourage the growth of minerals over the mesh. This in turn creates the perfect environment for the growth of barnacles, oysters and mussels, which as they grow over the Biorock reef they hold the rocks together further reinforcing the structure.

In January 2016, just before the monsoon season set in, 48 Biorock Anti Wave reefs were installed in front of the 200 metres of Gangga Island’s beach that was worst affected by erosion. Almost immediately the beach started to regrow. Since 2016, Gangga’s beaches have completely grown back. This is thought to be one of the fastest beach restorations ever done with results that have astounded locals and scientists alike. Even after a severe storm in January 2017, the beaches are back to their former glory already... and possibly even better than before. The Bioreefs have also created beautiful new environments for new coral and sea grass growth where fish and other marine life have made their homes and are now thriving. This is solid proof that wave-absorbing structures can grow beaches back. Seawalls are more expensive, more intrusive and actually accelerate coastal erosion. Dredging, sand dumping and other methods are equally ineffective. Gangga Island’s regrowth shows that the Biorock technology is the way forward for protecting our beaches, low islands and coasts. Billions of people’s homes and marine habitats can be saved with this simple, cost-effective method.