A day for Eco Warriors!
What is a Bio Rock?
Biorock technology has been invented by Professor Wolf Hilbertz and Doctor Thomas J. Goreau at the end of the 1970s.
Biorock structures are made with crisscrossed metal stems which are crossed by a low-voltage current of 1,2Volts. These structures are installed on the ocean floor and pieces of corals are attached to them. These corals come from reefs in the neighborhood and were broken for various reasons (unaware divers, strong waves…).
Scheme of the Biorock system
The electric current, which is totally harmless for any organism, leads to electrolysis, causing a calcareous precipitation on the whole structure. This will not only avoid the unwanted appearance of rust which would weaken the structure, but, as coral’s skeleton is made of calcareous, the structure will, thanks to this reaction, become the best place for coral to develop.
Thus Biorock technology relies on a very simple principle: reproduction by electrolysis of the natural reaction occurring between coral, sea water, sun and dissolve minerals.
Our Plan of Action
On the morning of the 28th February, we went on a dive to the dive site, ‘Secret Reef’. Regarded as the best coral dive site around the islands, we collected dying and broken pieces of coral which we would later attach to a bio rock structure. We also helped revive some corals that had been broken and turned upside down, such as the table corals.
Later in the afternoon, the dive site was of course our ‘house reef’, the bio rocks. With thick bristled brushes we cleaned the structures of algae and other organisms that take the nutrients needed for growth such as Drupellas which are a type of sea snail.Then the broken corals we had collected were attached to the structure using cable ties.
Results of Bio Rock Structures
We should rather say that Biorock technology’s electrolysis is catalysis of the natural reaction and not only a simple reproduction, as this electrolysis enables a coral’s development 2 to 6 times faster than in usual conditions. Normally coral grows from only some centimeters per year. And so getting its growth quicker is an efficient way to restore reefs.
Moreover coral on Biorock structures grows stronger and is more resistant to hazards it faces.
Hard corals are not the only ones to grow on Biorock structures: tunicates, bivalves, sponges and soft corals also come to develop at speeds higher than the average. On a Biorock structure, their survival and resistance rate is 20 to 50 times higher than in natural environment.
Finally, because Biorock technology relies on electrolysis, its impact benefits all corals and ecosystems around the metal structure in a perimeter with a wingspan of about ten meters.
Biorock structure, one year and a half after its installation
These already studied and proved by W. Hilbertz and T. Goreau facts are born out since the 1980s by the efficiency of Biorock structures installed all around the world. These structures contributed to damaged coral reefs’ restoration, enlargement of beaches touched by erosion, repopulation of marine areas with many species of fishes and other sea organisms
WITH HUGE THANKS TO DELPHINE ROBBE FROM THE GILI ECO TRUST FOR HELPING ORGANISE THE BIO ROCK DAY. FOR MORE INFORMATION ON THE BIO ROCKS AROUND THE GILI ISLANDS, VISIT WWW.GILIECOTRUST.COM!