BioRock: Saving Indonesia’s coral reefs

“Gear check; regulator, mask, open tank,” shouts Delphine, as we shuffle backwards to let our tanks hang over the ledge of the pump boat.

“Reef check equipment; baskets, tweezers, gloves,” she adds. The nose of our boat kisses the lip of a wave, jolting the horizon ahead at a 45 degree angle. It doesn’t stop Delphine from throwing herself into the choppy waters. We all follow.

By the time I resurface, my mask is vertically swept across my face and my regulator is spurring out of control. The currents pulling us like threatening gusts of wind, we begin our descent.

I expect to be greeted by the brilliant rainbows of reds, blues and greens that famously compose Indonesia’s complex marine ecosystem. Unfortunately, all that’s left is a graveyard of corals bleached deathly white, the rest shattered to pieces from explosive fishing methods, or poisoned by cyanide.

Delphine Robbe is a French eco-warrior who moved to Indonesia in 2004. She is the driving force behind the Gili Eco Trust, a non-profit organisation set out to protect the local environment.

In 2005, she introduced BioRock to the Gili islands with the help of Foued Kaddachi, which has reinstated an underwater metropolis with innumerable connections to the surrounding ecosystems. Her determination and passion for the environment has restored an eco-friendliness in the Gilis, earning her an award of ‘Woman of the Year of South East Asia’.

Different shaped BioRock resting on the ocean bed

A BioRock in the shape of a dolphin rests on the ocean bed

The BioRock technology was invented by Tom Goreau, director of an environmental group called the Global Coral Reef Alliance, and Professor Wolf Hilbertz,  both of whom won ecotourism and environmental awards for their invention. The conditions of marine ecosystems in more than 20 countries have significantly progressed ever since.

In BioRock, a low electrical voltage current is applied to a rebar metal frame under water, creating an electrical field around the artificial reef, a process otherwise known as electrolysis.

The steel structure grows solid limestone minerals which provides corals with a good substrate to grow on. Corals are then collected and mounted onto the structure to let their limestone skeleton merge with the metal which, in turn, will eventually disintegrate.

This technology mimics the natural process of reef formations, when colonies of tropical marine plants and animals rise atop earlier generations. Scientists have found that the electrical current in BioRock helps coral reefs grow faster and remain healthier. It provides breakwater material because it grows stronger with age and repairs itself if damaged by heavy waves.

The 85,000 km of coastline in Indonesia once boasted 75 per cent of the ocean’s marine biodiversity, and half a dozen protected marine areas. The shallow continental shelf that supports the Indonesian archipelago provides an ideal pedestal for growth.

The marine wilderness that seeded the world’s most elaborate coral complex is still found thriving in some areas of Indonesia, such as the protected marine parks of Palau, where some of the planet’s lushest array of marine life to date can be found.

Together the Indonesian and Philippine archipelago contain about 21,000 islands and nearly one fifth of the earth’s coral reefs; it’s widely referred to as the Coral Triangle, due to it’s geometrical form. A single bay in the Indo-Pacific sea may contain as many coral and fish species as grace the entire Caribbean. 

 All that’s left is a graveyard of corals bleached deathly white, the rest shattered to pieces from explosive fishing methods, or poisoned by cyanide. 

In recent decades, coastal ecosystems have lost their biodiversity to hurricanes, destructive fishing methods, coastal development, pollution, careless tourism and climatic extremes such as El Nino.

The average temperature of tropical oceans has increased by 7ºC, which has resulted in extensive coral bleaching around the globe.

The Gili islands, located between Lombok and Bali, were discovered by fishermen in Sulawesi just over 50 years ago. Seduced by white sand beaches and turquoise waters, they were the first to settle.

The biggest of the three islands, Gili Trawangan, is no longer than three kilometres in length, and home to 20 dive sites. The smallest, Gili air, is closest to the much larger island of Lombok.

The discovery of the Gili islands prompted an influx of boats and divers, putting new pressure on the underwater ecosystem; the boats pollute the water and everything in it with petroleum products and sewage.

“It can take up to six years before we see some of the reefs recover from this damage. Some have fully recovered, some might never,” reflects dive master Sian Williams, Delphine’s right hand in managing the Gili Eco Trust.

In an attempt to sustain their livelihood, local fishermen have turned to cyanide fishing; by squirting the chemical onto coral colonies, then prying them apart with a crowbar, enabling them to capture stunned fish hiding in the crevices.

“They can only fish like this a few times before they’ve got no reef left, which the fish can’t live without,” adds Sian.

Since her arrival, Delphine has worked closely with locals to ensure their cooperation in caring for the environment. “They are very happy to participate in the BioRock projects, they help to build them, they come diving to collect corals, some of them are so proud of the BioRock structures that they bring their guests to snorkel on it every day.”

Acropora Phulchra resting on BioRock

A healthy species of Acropora Phulcra rests steadily on a BioRock

Ten metres below us; Delphine has already removed a couple of Drupella snails and one Crown-of-thorns starfish from a branch of Acropora. Both species are well-know predators to coral reefs of Indo-Pacific oceans.

At high population densities, the Drupella snails leave scars from their feeding habits, killing extensive coral areas which are left to be colonised by filamentous algae.

The Crown-of-thorns starfish, although less ubiquitous than the Drupella snails, feed on coral by extruding their stomach and smothering the coral, then secreting digestive enzymes. Only mass coral bleaching events and cyclones are more destructive to the coral reefs than the Crown-of-thorns starfish.

Although both of the species are indigenous to the ecosystem, scientists suggest that the uncontrollable growth rate in their colonies is a consequence of human activity. The more sewage pumped into the ocean, the more these species feed.

When I ask Delphine whether she believes that BioRock can keep up with the damaging impact of the global warming on the ocean, she remains pessimistic: “I don’t believe we have found a solution for stopping the detrimental impact on the corals, but what we have managed to achieve with BioRock is the preservation of the marine biodiversity. By installing BioRock in as many locations as possible we have saved some coral reefs.”

Following a morning of an extensive Reef check, we gather on the beach to build our BioRock structure. Long strips of rebar steel are welded together to form a dome, which is then transported to its designated location by boat, where it will be submerged.

Seven finless divers sink the structure and walk across the seabed seeking patches of crushed reef, then anchor it accordingly.

Today we travel to Gili Air, where a resort has requested a BioRock structure to be installed in front of their hotel. Due the rising sea levels, the erosion has been eating away at the beaches that circle the island.

“13 years ago, low tide would expose up to 30 metres of sand and reef. Today we see only five metres of sand during low tide,” reflects Delphine.

Although scientists have said that sea levels continue to rise by 3-4 mm each year, studies show that BioRock grows upwards by 20mm per year, providing additional defence against erosion.

The collective structures eventually grow strong enough to act as a buffer against heavy seas, and have already allowed some beaches in Gili Air to reclaim up to 10 metres of sand back.

“When a business wants to contribute to the BioRock project, they will pay a fee to get the technology installed at their convenience. Thereafter it’s up to the Gili Eco Trust to maintain and expand each BioRock site with the eco tax money,” explains Delphine.

“I have trained many government people who are always happy to contribute. They now also use us as consultants for any new BioRock projects that they can find funding for.”

A fish swims beneath BioRock

Some BioRocks are more vulnerable to the heavy tides and can easily get damaged by strong waves.

The 130 structures submerged beneath the Gili waters make Indonesia the most advanced BioRock centre in the world. Many recently-certified divers looking to heighten their experience in the heart of the coral triangle come to Gili islands to learn about the innovation.

The dive shops in Gili Trawangan have added an additional tax fee to each dive that goes towards funding BioRock and continue to push for eco-friendly tourism.

“Because of the power supply that we feed our BioRocks, they do need a lot more maintenance than other types of reef restoration,” says Sian.

The Gili Eco Trust works closely with the dive shops, using their expertise to maintain buoys, clean debris off the reef, help with research projects, educate the public and reposition coral branches which have been knocked off their colony.

We travel to Deep Turbo, a dive site at the northern tip of Trawangan, to collect healthy corals to adorn our naked structure.

Underwater, a Blacktip reef shark swims past us, but the dive team is more taken by a shy Harlequin shrimp spotted above a vibrant tree coral. Delphine pulls out a decomposing nappy from underneath the coral and stuffs it into the front pocket of my buoyancy compensator, inoffensively.

We continue to drift weightlessly in the current, picking up branches of broken coral from a wall that seamlessly drops into the abyss. Reef gardening somewhat feels like grocery shopping, minus the overwhelming sense of gravity.

As we enter deeper waters, life prevails. Protected by the colder temperatures, the corals here remain safe from bleaching.

The wall before us holds a broader representation of earthly life; coral branches reach out into pinnacles to absorb the distant light, configurations that have developed such due to the near absence of gravity. What appears to be a larger bolder, is actually a colony of millions of creatures.

Squid swims beneath BioRock

A squid swims beneath a storm-damaged structure – although the corals sometimes fall off the BioRock, the structure itself remains strong enough to hold fresh ones

The confined space of our baskets forces us to opt for branches only slightly bigger than our hand. Daisy, Leather and Pincushions species boast bright blues, pastel pinks and opaque oranges. Because they have fallen off their colony, I allow myself to take the lot.

Although corals are often mistaken for colourful plants, they use tentacles with stinging cells to feed on microscopic prey travelling in the current. In a state of excitement, I forget that bright colours typically signal danger and reach out for a fluorescent green branch guarded by a crab.

A raging sting penetrates my glove, instinctively urging me to let go. I later learn that the mistaken coral is in fact a stinging Hell’s Fire anemone, a member of the Hydrozoa class, more closely related to jellyfish than coral.

The tremendous burn serves as a good reminder that reefs are a world where colour is clearly a matter of life and death. 

During the 1997-1998 El Nino event, widespread and severe coral reef bleaching claimed 16 per cent of the world’s coral reefs in just under 12 months.

Our nearly empty tanks force us to return to the surface. “Incredible, I’ve never seen anything like it,” says Jo, a marine biologist who has travelled from Granada with the ambition of setting up his own BioRock project in the Caribbean.

We begin to identify the corals and divide them in preparation for our next dive; which will be dedicated to sprucing up our very own BioRock Structure.

Indonesia’s location is a crossroads for the Indian and Pacific oceans, which makes it vulnerable to the heavy tides that travel through the archipelago.

The El Nino current has claimed up to 50 per cent of Indonesia’s reefs in the past 30-40 years. During the 1997-1998 El Nino event, widespread and severe coral reef bleaching claimed 16 per cent of the world’s coral reefs in just under 12 months.

“The 1998 and 2015 bleaching events were by far the most damaging,” reflects another diver, Robbe.

The Zooxanthellae algae is responsible for giving the coral its colour, and provides the polyp with 98 per cent of it’s food source. This symbiotic relationship can only exist within the narrow band of environmental conditions; the water must be clear, shallow and range between 23°C and 29°C to ensure that the light can reach the algae for photosynthesis.

When El Nino patterns raise the sea-surface temperature, the corals react by expelling their zooxanthellae, leaving limestone skeletons to show through transparent tissues. If the bleaching is mild or short-term, corals can recover and the algae will recolonise.

If the bleaching lasts too long, the corals starve to death. Sian Williams recalls only three rainfalls in the most recent rainy season, which typically begins in November, and ends in March: “There weren’t even any clouds, so the oceans heated up so much, it felt like a bathtub.”

Electrolysis process

A close up on the electrolysis process of BioRock, where limestone begins to form over the rebar steel

The use of electricity in BioRock has previously raised concerns that the technology could be harmful to surrounding ecosystems, “many people think it is bad to use electricity, but research shows that this is how BioRock maintains biodiversity and helps corals survive mass coral bleaching or other stressors due to pollution or climate change.”

Although Delphine once attempted to derive an electrical current from solar panels positioned on buoys, they were quickly stolen.

The titanium mesh, which is used as an anode of the BioRock, is also sought by many locals who use it to detect gold.

Studies show that the corals on BioRock see 1,600 per cent to 5,000 per cent higher survival rate than corals on nearby reefs after severe bleaching events.

Robbe believes that BioRock is what saved most of the reefs in the Gili islands after this year’s El Nino event: “We monitored the corals during bleaching event to find that those on the BioRock had a much better survival rate.”

Although BioRock has been introduced in more than 20 countries, the technology is patented, which renders it inaccessible to others.

“BioRock is a slow process, many people have tried to replicate the technology but were unsuccessful, entailing bad promotion for the technology,” adds Robbe.

Sian uses the fringing reefs as a reference point to lead the team down to our newly positioned structure, where we begin attaching the corals.

In only seven metres of water, the shallowness challenges our buoyancy, the currents drag us helplessly across the seabed forcing us to latch on to the rebar metal with our fingers.

Each coral is attached using a small plastic tie. We are trying desperately not to let ourselves be pushed onto the newly mounted corals.

A few metres away a local free diver is chasing a female sea turtle, catching Sian’s attention. Furiously, she chases the free diver to the surface where a flock of tourists await him: “What the hell do you think you’re doing?” she yells in her best Indonesian.

She explains to them the importance of leaving the ecosystem untouched and the stress any physical contact will cause the turtles.

“It is so important that we inform them about these things, unfortunately the locals are quite limited in their knowledge about the ocean, even though they heavily depend on it for their livelihood,” she tells me later.

Delphine points over at a small fluorescent green sea slug covered in symbiotic blue and green algae, its electric colours accentuated by the surrounding greyness.

The nudibranch uses solar radiation to produce carbohydrates for food. Unlike other neglected coral-eating species, this slug is a novelty in marine ecosystems and a symbol of hope in these waters.

Divers swim over BioRock

Reefs protect coastlines from damaging effects of wave actions and provide habitats and shelter for many marine organisms

To explore the biodiversity living on BioRock reefs, my dive partner, Johan Meny, free dives over the lip of a patch reef into a playground of structures.

From the surface I can make out metal structures resembling sharks and stingrays, each providing the reef with nooks and niches that promote biodiversity for different species.

Underwater, the rebar metal has turned white, as limestone minerals that are naturally dissolved in seawater grow over the surface.

Complex tangles of coral polyps continue to grow from their foundation, some already hosting a multi-hued school of colourful fish above it. A couple of the structures have already become home to an array of soft and hard corals, tunicates and bivalves in just over a year.

A two hour snorkel allows us to check that all the structures along the east side of Gili Trawangan are intact.

For each structure, we swim down to the titanium anode connected to the power source, and sip in the water seeping around it. The taste delivers a bitter metallic tanginess, confirming that the structure is receiving an electrical current and excreting limestone (calcium carbonate).

Johan and I finish the survey by identifying which species of fish are spotted near the BioRocks. The first to catch our attention are a small flock of Parrotfish excreting white sand over our heads.

They can devour up to five tonnes of coral per year, gouging out chunks with their teeth, which are fused into a beak. A second powerful set of jaws deep in the throat will crush the coral. Their droppings contribute to the production of tropical sand that make up pristine white beaches of Indonesia.

Once the corals die and dissolve, they mix with bird droppings to glue the grains together that build the foundation of an island.

This partnership plays a role virtually everywhere you look on the reef. By the end of the dive, we started to feel like we ourselves were joining the ecosystem.


Featured image by Foued Kaddachi