Posidonia

The lung of the Mediterranean

Posidonia is not an algae but a flowering plant consisting of bundles of leaves grouped on rhizomes (underground stems).

It forms underwater meadows called seagrass beds, located just below the surface and down to approximately 40 meters deep.

It is endemic to the Mediterranean.

Occupying an area of 1 to 2% of the seabed, seagrass beds harbor nearly 25% of Mediterranean biodiversity.

The seagrass bed constitutes the basis of the richness of coastal waters and serves several roles:

• An ecological role as thousands of animal and plant species find refuge or use it as a permanent habitat.
• A role in determining the quality of marine waters because it is very sensitive to pollution.
• A role against coastal erosion as the rhizomes retain sediments in the seabed, the leaves attenuate the action of currents and waves, and the beds protect the beach from storms