As part of the Larvotto land extension project, the Prince’s Government has launched an ambitious transplant operation for Posidonia, a protected underwater plant. A significant portion of the plants has been moved to two sites: within the Larvotto reserve and at the foot of the Fontvieille dyke.
Bouygues Travaux Publics, which is carrying out the maritime infrastructure works in collaboration with Trasomar and Andromède Océanologie, has just completed the transplantation of 500 square metres of the plant.
Posidonia oceanica is emblematic of the Mediterranean. Today it’s a protected species and constitutes a major marine ecosystem with a large biodiversity. It is also a source of oxygen and a trap for carbon.
There is currently no proven method for such a transplantation operation. Prior to the move, a scientific research operation was conducted to optimise posidonia displacement involving 637 metal baskets covered with canvas of biodegradable coconut fibres.
Pierre Descamp, managing director of Andromède Océanologie, has been involved in the project for more than two years. He said: “Replanting the posidonia in the reserve was quite simple: we dug several holes in the sediment to the width of our specimens and once the plant was installed, we filled the interstices. In order to maintain its characteristic structure in a herbarium, the baskets were tightened to the maximum.”
In Fontvieille, the relocation took place differently. Planters were installed 14 metres deep to accommodate the baskets. The baskets were set with sediment so that the plant could live and develop there.
Marie-Pierre Gramaglia, Minister of Public Works, Environment and Urban Development, said: “After the displacement of 147 large molluscs from the area of the future extension to the Larvotto reserve, transplantation of 500 square metres of posidonia is the second major operation in the preparatory environmental work. A follow-up over 10 years, will ensure the success of the movement of this protected and emblematic species.”