- The underwater sculpture Domus Musculi, or House of Mussels, is "a remembrance of what the Jakarta Bay has been famous for: its mussels, which nowadays are no longer exist due to heavy pollution," according to the artist Teguh Ostenrik's website.
- The sculpture uses Biorock technology, a patented artificial reef system that involves coursing electricity into the sculptures’ steel frames.
- Ostenrik has installed other artificial reefs in the waters off Lombok and the Wakatobi islands.
It’s a diver’s bane: beautiful and interesting sites, but low visibility. This year, Indonesia’s anomalously wet dry season overlapped its stormy rain season. Yet, while Jakarta proper was inundated, the northern part of its Thousand Islands bathed in sunlight and bright blue skies till early afternoon. As darkness raced to the horizon, the sea turned black and choppy. It was not a good time for broken-coral hunting, but the volunteer divers on Sepa Island were relaxed and happy after a successful morning planting corals on the Domus Musculi.
Named in honor of the green mussel, Perna viridis, Teguh Ostenrik’s underwater sculpture Domus Musculi — House of Mussels — is located by the Sepa Island quay. Before they were contaminated, Jakarta used to be known for its green mussels, said Ostenrik.
Factory drainage, wastewater from home industries and polluted rivers streaming into the Jakarta Bay for more than a decade have degraded water quality to an extent that mussels have been found contaminated with heavy metal, such as mercury, cadmium and lead. A study by marine biologist Neviaty Zamani deems Jakartan green mussels inedible because of constantly rising levels of contamination, now above the accepted Indonesian government and Food and Agriculture Organization/World Health Organization levels.
The Indonesian media regularly reports on people falling ill from eating green mussels from the bay and elsewhere in the country. Mussels, according to another study Zamani participated in, stick and reproduce on ferries which also transport them to new habitats. So far, attempts at correcting the problem have mostly been limited to healthier mussel farming. Yet, the Jakartan green mussels are also heroes. Biologically unable to discharge accumulated contamination, green mussels serve to mitigate seawater pollution.
Ostenrik, who has conceived many environmental artworks, feels Indonesians should take their ocean more seriously. “Indonesia is an archipelago, we are surrounded by the sea, we are all connected by it, but we turn our backs to it. My ARTificial Reef series honors the sea.”
Domus Musculi is Ostenrik’s third installation using Biorock, a patented artificial reef system that involves coursing electricity into the sculptures’ steel frames. The first, Domus Sepiae, is located in Lombok, followed by Domus Longus in Wakatobi.
At Sepa Island, three 5-meter-long steel structures form a curved tunnel to swim through. Its grid frames decorated with steel mollusc-like plates were more than half full with budding coral pieces. Some had already grown one centimeter longer, while others had fallen off and died. This was a reconnaissance trip meant to check the condition of the twice-sunken structure. The Domus Musculi was first placed near Pelangi Island before it was reinstalled this year at Sepa Island, at a depth of 5-12 meters. According to Mira Tedja, founder of the ARTificial Reef Foundation, which organized the installation, the move was necessary because the living artwork needed community involvement, people who would regularly check the corals’ growth. Wind, water currents, condition of corals and topography are other determining placement factors.
Rechecking and photographing both old and newly planted corals, diver Catherina JT explained how important it was to plant the corals correctly. “A coral grows upwards and needs the sun, the body and bottom of the coral must stick to the grid so it can get the maximum electric current which helps it grow. If the plastic straps holding them are loose, there is a chance that the position changes and the corals fall off or just die there dangling on the grid,” she explained, adding, “That would be a real shame.”
Solar panels placed on the jetty produce a mild electric current that travels to the bottom of the tunnel before distribution to the steel frame. The electric current causes water, carbon dioxide and trace elements in the vicinity to recombine as calcium carbonate — the compound that feeds and strengthens corals and seashells. The system makes for swift growth of corals, up to six times faster than in nature.
The Biorock system used by Ostenrik was invented in the 1990s by biochemist Thomas Goreau and the late German architect Wolf Hilbertz. Learning directly from the two, marine biologist Ramadian Bachtiar oversaw the installation of Domus Musculi in Sepa Island.
Hilbertz, like Ostenrik, was an artist and diver. He had built artificial reefs in many parts of the world, including Bali. At Pemuteran Bay, his award-winning installation consisted of various sized forms of sea beings. Unfortunately, a landslide crushed the installation beyond recovery.
Ever the environmentalist, Ostenrik blames the landslide on massive cutting of trees for new hotels in the area. “What I do is small, like a grain of salt in a sea of problems,” he said. “The Domus Musculi can only handle 20 visitors a day. It is not per se a tourist attraction. ARTificial Reef is an entry point to learn and work together for conservation.”
The Domus Musculi team of volunteer divers included filmmakers and advertising professionals. Their films and photos will be shown on Sepa Island for locals and visitors to see and perhaps, think about.