Posidonia oceanica: the hidden forest that protects the sea

A joint project by Emerald Holding and One Ocean Foundation to preserve the balance of marine ecosystems

An expanse of green covering the seabed, dancing sinuously with the depth and movement of the water, providing shelter, food and a place to reproduce for over 350 species that inhabit the area: this is the meadow of Posidonia oceanica in the bay of Cala di Volpe. The area of approximately 80 hectares of sea within the mooring zone had been damaged over time by unrestricted anchoring, and is now protected by regulated access, but above all allowed to re-grow, thanks to the Blue Forest reforestation scheme, implemented by a partnership between Smeralda Holding and the One Ocean Foundation.

One Ocean Foundation

The first step towards protecting the Posidonia and the underwater prairie was actually carried out 20 years ago by Smeralda Holding, with the creation of the buoy field to limit the pressure of human activity in the bay. The company’s commitment to environmental protection continued year by year, as we joined forces with the non-profit foundation and eventually replanted root cuttings of the marvellous aquatic plant over an area of some 500 square metres. Bio-matting made of coconut fibre and metal mesh was installed on the seabed to receive approximately 20 plants per square metre. The scions, taken solely from those naturally removed from the settling basins in the bay, were combined with the experimental planting of shoots from seagrass fruits washed up on the beach from exceptional winter flowering events.

The bay of Cala di Volpe is an area of enormous environmental value, its habitat a fragile ecosystem that must be protected both on the beach and in the fascinating depths. Posidonia oceanica and its meadows are a treasure trove that encapsulates essential drivers of biodiversity and ocean health. A protected species worldwide, it grows solely on Mediterranean coastlines at a depth of some 40 metres, forming large prairies that act as a natural barrier to coastal erosion. This seemingly simple plant turns out to be one of the main coastal producers of oxygen, and is an essential ally in the fight against climate change, since it can store huge amounts of carbon dioxide in marine sediment, removing it from the atmosphere and potentially locking it in permanently.