World - ‘Real estate’ for corals: Swiss organisation builds artificial reefs with art, tech
3D-printed clay sculptures that provide shelter to corals are part of an innovative, artistic project aimed at conserving sensitive marine ecosystems. As world leaders gather for the COP28 summit in Dubai, FRANCE 24 takes a look at an unusual conservation project run by a Swiss NGO.
In the depths of Lake Geneva, near Switzerland’s second-largest city, a team of divers began work on an underwater castle – a marine palace fit for corals.
Rrreefs, a Zurich-based organisation founded in October 2020 that designs artificial coral reefs in clay using a 3D printer is an ecological project that combines art, science and new technologies.
Stacked on a platform, the clay sculptures looked like dungeons waiting to be sent to the bottom of the sea. Ochre in hue with ribbed surfaces, they were soft to the touch and weighed 7 kilograms. They have been carefully designed to collect coral larvae carried by ocean currents. When encrusted, these tiny animals can develop the hard skeletons that eventually form a natural reef.
Although coral reefs make up just a modest portion of the seabed, 25 percent of underwater life depends on these fragile structures. Their benefits are manifold: Reefs serve as a refuge, a breeding ground and a source of food for fish, and protect coastlines from erosion.
Maintaining corals’ resistance to global warming
Mountains of coral – jewels of the natural world – are disintegrating due to overfishing, water pollution and marine heatwaves. Half of them have died over the past 40 years.
"When stressed, corals expel the symbiotic algae that feeds them and starve to death," explained Rrrefs co-founder Marie Griesmar, sporting a T-shirt emblazoned with a fish.
She stretched out a hand to her co-founder Hanna Kuhfuss, hampered by her wetsuit, to lift her out of the water.
Rrreefs does not claim to stop the coral disintegrating but it is on a mission to offer shelter to surviving larvae and give coral reefs a second chance to grow and take in other living organisms.
"I'm an estate agent for special animals," Griesmar said with a smile.
“What I like about our project is that it uses a passive restoration method,” explained Kuhfuss, a marine biologist by training. “Other coral preservation systems use cloning, but if one of the organisms is sick, it affects them all. Our technique lets nature take its course, encouraging the development of the offspring of corals best adapted to global warming. By relying on natural reproduction, we can maintain their resistance.”
Four complementary talents
Rrreefs draws on the talents of four different people. The idea for the project was first sparked at Swiss technology institute ETH Zurich, where Griesmar, an art student, was thinking about how she could connect her passions for art and diving. She crossed paths with Ulrike Pfreundt, a scientist specialising in the preservation of tropical ecosystems, who was doing her final-year project on the effects of currents on artificial structures.
