Fieldnote: Touching calcification in the Port of Marseille
After stripping to my trunks, I slip into large dive fins and put on a pair of googles. Then, I glide over large boulders into the warm water of the lagoon. Guillaume looks a little nervous. We informed the port authority of the dive, which is obligatory, but he forgot to replace the batteries in the walkie-talkie. Radio contact is required for dives in the inner harbour. Guillaume is an stress-resistant type of person, which might result from his yoga practice. “You’re good to go,” he says. Guillaume points to the area where I would find the submerged samples of Géocorail. The water is all shades of green but seems to get murkier at a depth of two meters. I cannot see to the bottom. So, I try my luck, take a deep breath, and make my first descent. The seawater in Marseille-Fos Port, the main seaport of France, is heavily polluted by industrial effluents. Guillaume’s colleague, Thomas, a biologist by training and professional diver, warned me of diving too close to the bottom because it would stir up fine mud particles and further cloud the water, making seeing underwater impossible. After about three unsuccessful attempts, I finally glimpse them: greyish tubes and metal grids fixed to the ocean floor. Over the next 10 minutes, I repeatedly drop to a depth of 5m to “witness” first-hand the transformation of a network of metal strings into “natural concrete” or Géocorail. I go toe to toe with earthly formation.
At the bottom of the lagoon, metal grids are constantly accruing mass and volume, producing Géocorail – a material as robust and durable as rock. Seacure, the company marketing Géocorail since 2012, claims to produce “natural concrete” by mimicking biomineralization, an evolutionary trick used by corals to create hard shells from minerals available in water. Géocorail, which is both a brand secured by copyright and a patented invention, ostensibly combines the prefix ‘geo’ from the Greek geos, earth, and the French word corail, which means coral. While the prefix alludes to the solidified features of shorelines that the company wants to protect, retrofit, and nourish for its clients, corail insinuates the organic or natural procedure that the company mobilizes to achieve this.
