Electric current flows through seawater, and corals that were near death recover.
Don't
judge a book by its cover, and don't judge a sea by its beach. The
second motto is appropriate when you visit Pemuteran, in northwest
Bali. At first glance, the black sand beach here seems nothing special,
though the beach is clean and the sea is calm. There are a few foreign
tourists sunbathing far from the shore, at several resorts to the west
of the Reef Seen Aquatics Dive Center.
But what you see on the surface does not reflect the underlying reality. Twenty or thirty meters from shore, at a depth of two to eight meters below sea level, guests who are enjoying their first snorkeling experience or in a glass-bottomed boat will be amazed by the many giant steel structures encrusted with all sorts of beautiful corals, with a variety of fish swarming among them.
Despite the lack of publicity, this site off Pemuteran is the world's largest Biorock project, far larger than similar projects in Lombok, Thailand, the Maldives, or America.
Biorock is a method of fostering coral reef growth through Electrolytic Mineral Accretion Technology. The technique was invented by Prof. Wolf Hilbertz, a German architecture professor , and Dr. Thomas Goreau, an American marine biologist. Simply, it involves passing a direct (DC) electrical current into sea water.
At first, Hilbertz used the technique to build undersea structures, using the calcium carbonate naturally occurring in the seawater as the material, stimulated with direct current. The project went very slowly, but Hilbertz then discovered that in the structures he was building, various types of coral of different shapes and colors were starting to grow. And when he met Goreau, who was active in coral reef restoration projects, they became convinced that this technique, which they decided to call Biorock, could be used to accelerate regrowth of damaged coral reefs.
Pemuteran was chosen because it had already begun to look after and protect its reefs. Since coming to Pemuteran in 1992, Chris Brown, Reef Seen's owner and founder and his staffs spent a great deal of time chasing off the dynamite and cyanide toting aquarium fish collectors, whilst at the same time repairing damaged reefs, removing crown-of-thorns starfish (70,000 between 1996 and 1998) and educating the local fishermen as to how and why they needed to protect their reef resources.
But when the El Niño weather phenomenon caused seawater temperatures to rise, the corals suffered bleaching, and many died. And then, with the economic crisis starting in 1998, many fishermen again started using explosives and poisoning fish with cyanide, and the reefs became badly damaged.
The first Biorock project structure, known locally as Proyek Karang Lestari (Everlasting Reef Project), was built by Goreau and Hilbertz in June 2000 in cooperation with the owners of several resorts and dive centers and local people in Pemuteran, in the sea near Pondok Sari Hotel and Reef Seen Aquatics. Three more structures were built in October 2000. There are now 50 Biorock structures of various sizes and shares along the sea bed off Pemuteran, covering an area of 300 meters.
Frankly, though I do understand a bit about chemistry, I couldn't
grasp how the electric current in the sea water would stimulate coral
growth. Luckily, that morning I met Mike van Hugten, a freelancer who
has for a year been helping Chris, with maintenance of the Biorock
project and other projects involving the local community.
"Biorock works by flowing a direct current through cables from a power source on land to a positive pole (anode) and a negative pole (cathode) in the sea," Mike explained, using a whiteboard. "As the anode, we use a titanium wire frame, while the cathode is a steel structure with bits of coral planted in its gaps. The two poles are placed near one another. The power supply, which comes from PLN (the state power company), is converted into direct current at 9 to 15 volts."
Mike explained that when the current is activated, a chemical process occurs in the sea water whereby the minerals in it are extracted and deposited on the cathode. As this mineral accretion process continues, a white layer grows on the surface of the structure, which is simply limestone, or calcium carbonate, the same material that coral reefs are made of.
Because the structure is filled in with bits of coral, the mineral adheres to the coral, and eventually the coral adheres to the structure and starts to grow. "Coral grows naturally in just this way, but very slowly. Using Biorock, the growth process can be sped up three to five times, depending on whether it's a fast growing or slow growing coral species," our Dutch friend explained. Then, various types of fish begin to frequent the area, and a new ecosystem has been created.
Currently under consideration is how to replace the power supply from PLN with solar panels. Using power from PLN means contributing to greenhouse gas emissions, and thereby increasing global warming. Solar panels are the best alternative, because they are emission free and also switch off automatically. Mike explained that coral reefs grow and reproduce when there is sunlight. "With solar panels, we don't need to turn the power on and off manually."
However, good-quality solar panels that will last a long time, over 15 years, are quite expensive, aroundnÄ400-600 each, and just one steel structure with a 15-meter diameter could require up to six solar panels; even though they can produce the same voltage, the current produced by solar panels is generally lower, but this current is what is needed for the mineral accretion process. Another problem is that the Biorock process is sometimes applied in areas where the residents lack the funds to invest, and it is quite expensive. "But in business terms," Mike points out, "Biorock is not just a waste of money."
Mike explains: "Let's say you own a resort near the shore, and your guests come to go snorkeling. But they can't see anything because the reefs are damaged, so they're disappointed and won't come back. But if there are a lot of Biorock structures with lovely corals near the resort, this will attract tourists, thereby benefiting business, the environment, and the local community, so it's a win-win solution."
However, Biorock is not a technique you can just set up and then leave alone. It takes at least three to five years of continues support before the results are seen. Continuous maintenance is needed, for example to monitor the electrical supply and the condition of the current, the conditions of the reefs, cables, anodes and cathodes, and to preserve the conditions of the marine and coastal environment. Naturally, all this requires maintenance personnel.
Reef Seen, which has been involved in the Karang Lestari project
from the start, does this by training local fishermen as "reef
gardeners". They are trained as divers to be able to protect the
health of the reefs. For examples, they remove creatures that eat the
reefs, such as the crown-of-thorns starfish and the shellfish Drupella,
repair damaged cables, clear trash from the beach, build wooden boats
to transport tourists, and serve as guides for Reef Seen's new diving
locations, which include Bio-Wreck, Ships Graveyard, and Underwater
Temple Garden. They also help with the turtle preservation project
long under way at Reef Seen. Eighteen local fishermen are now working
as reef gardeners, eight of whom have PADI diving certificates, with
three more to join them this year.
Mike and the other volunteers recently put up information boards to educate tourists on proper snorkeling methods. Mike says that education for tourists is also important, because they are far more likely to damage the reefs than are the local fishermen. "Many tourists don't know the right way to snorkel," Mike explains. "Snorkeling should be done in a horizontal position, but a lot of people do it vertically, and end up stepping on the reefs. But even a fast-growing coral only grows three to four centimeters in a year, and a slow-growing one just a few millimeters. So the tourists can easily damage the coral faster than we grow it."
I asked Mike to show me the Biorock structures, and he gave me a choice: Would I prefer to use the glass-bottomed boat, go snorkeling, or go diving? Although I'm not that experienced, I opted for snorkeling. Mike immediately got on his wet suit and gave me a life vest and snorkel. We set off for the beach, and I saw the electrical cables leading from the onshore power supply west of Reef Seen into the sea. Mike pointed out a cable that had been damaged but since repaired by the reef gardeners, who glued it back using epoxy.
As noon approached, the sun was shining brightly and the waves were quite moderate. Even so, I asked Mike to hold on to me while I was snorkeling. "Can't you swim?" he asked. "No," I admitted honestly.
"Oh, no problem. I used to be a swim instructor. I'll hold on to you."
Mike's a big strong guy, so he had no trouble pulling my life vest by the shoulder while swimming. We followed the route of two cables we found, and in just a minute or two I discovered a prism-shaped Biorock structure frame lying on the seabed. It was about three meters long, and each steel rod had a diameter of 1-1.5 centimeters. A titanium frame lay around two meters away, partly covered with sand. We could see bubbles of chlorine gas escaping from the frame, indicating that the mineral accretion process was proceeding. The amazing thing was that the structure was covered with various different types of large, beautiful, colorful corals, some nearly a meter across. Even more attractive were the many small fish swarming amongst the corals.
We came to another structure – this time it was a big upward
spiral, forming a giant ball. As we got closer to the corals at the
top of it, I was worried I might step on them. Under the bright sun,
the colorful corals were clearly thriving. The framework looked like
a giant piece of children's playground equipment in the water.
Mike took me to another part, further out, where we found even more different structures: one resembling a giant tube lying on its side, another a long rectangular block, and one like a pillar planted in the seabed. "Since he's an architecture professor, Hilbertz has made more than just one structural model. This provides many different models that are all nice to look at, and also helps to test which models are most wave-resistant," Mike explained when we came up for air. The Biorock structures, he said, can also be placed further out, at a depth of 15 meters, but to see these would require diving rather than snorkeling.
Mike invited me to continue snorkeling to another area, and this time we came upon a large structure shaped like an igloo but stretching back around 10 meters, with each section of its frame filled with a variety of corals. Hilbertz calls this structure "Nautilus". We also saw several structures shaped like blossoming flowers, and another called "Caterpillar," with a semicircular frame-work around 12 meters long. There was also a structure made from large lengths of bamboo with steel stakes, forming parallel bars. And all of these were covered with large corals and surrounded by colorful fish.
After looking around for nearly an hour, we took a break, and Mike suggested we return to shore. As I floated, letting him pull me along, I couldn't stop wondering at what I had just seen. The people of Pemuteran are really lucky; in a quiet little village, with an ordinary-looking beach and sea, they have something truly out of the ordinary.
