3D artificial reefs to restore biodiversity

A few air bubbles burst on the surface of the water, then a black shape rises. Matthieu Lapinski emerges from the depths and removes his regulator from his mouth. “Have you seen sars?” “, asks Marc Bouchoucha, on the quay. “Yes, and a huge bank of Pageots! “ Diving weekend with friends? Underwater fishing ? The concrete and steel landscape of the port of Toulon hardly lends itself to this.

On this hot morning, in the middle of warehouses and boats, the two men are at work, on the quay of the French Research Institute for the Exploitation of the Sea (Ifremer). They are participating in a large-scale research program, started in the summer of 2020. Objective: to measure the effect of artificial reefs on the development of biodiversity. An ecological challenge in this very artificial part of the coast polluted by centuries of human activity.

In the water, Matthieu Lapinski, 31 years old. This marine biologist works for the ecological engineering company Seaboost, a start-up in Montpellier which manufactured concrete reefs and artificial reed beds, installed in June 2020 along the Ifremer quay. One year after their installation, he returns to the site to check the condition of the submerged structures. On the quay, Marc Bouchoucha, 40 years old. Doctor in oceanology at Ifremer, he coordinates a study which examines over four years the impact of these installations on fauna and flora.

It is he and his team who, every week, dive along the quay to identify, count and estimate the size of the different species that have settled. And there are many. “We have identified 41 species of fish that cannot be seen in the control areas. These initial results are encouraging ”, rejoices the researcher.

Behind him, the high hangars of the Mediterranean Center of Ifremer house the jewels of the French oceanographic fleet, such as the Nautile, this yellow submarine which brought up the first wreckage of the Titanic, and which can reach 6000 meters deep. The artificial reefs are only 6 meters deep. Composed of 3D printed concrete, these three structures weighing 200 kg and 2 meters in length resemble public benches, all in curves and waves. The tortuous folds formed by the concrete create cavities that serve as shelter for the fish as they grow. Specially designed to serve as a nursery, they are completed by 150 m² of polypropylene herbaria, fixed vertically along the quays.

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