Posidonia Oceanica

1 cm/year


Stores CO2

Natural shelter

Posidonia is a marine plant, not an alga, which has roots, stems, leaves, fruits and flowers, grows 1 cm per year and forms grasslands that can reach a maximum depth of 40 meters. Posidonia oceanica represents one of the fundamental natural values in the Mediterranean as it plays an important role in sediment filtration, thus giving the water a unique transparency, helps maintain the quality and oxygenation of the ecosystem by producing oxygen and storing CO2, protects biodiversity by acting as a shelter where more than 400 species of marine plants and 1,000 species of marine animals feed and reproduce, and finally the beached posidonia leaves form quays which prevent coastal erosion.
This ecosystem is able to capture CO2 from the atmosphere, changing the acidity of the water and carrying out a fundamental role in regulating the ecological balance of the sea.


These ecosystems, which occupy about half a million square kilometers (km2), are in decline globally, with an estimated loss rate of 1-2% per year, four times the tropical forest loss rate, the percentage rises and reach 5% in the Mediterranean. Furthermore, the slow growth of these plants (1 cm / year) and the low production of seeds mean that the losses are irreversible, as the recovery of Posidonia takes several centuries.

The main threats are

The mooring of boats whose anchors and chains sweep the seabed destroying the underlying grasslands.
The discharge of bilge water (waste water, oils and hydrocarbons) from all types of boats.
Marine pollution, mainly of terrestrial origin, such as wastewater treatment plants, which produce turbidity by blocking the sun’s rays necessary for the photosynthesis of the plant, which makes it difficult for the plant to survive.
The extraction of sand and dredging in the ports, docks and docks of the coast.
Fishing practices that destroy the seabed.

The presence of invasive species such as Caulerpa taxifolia which are gaining ground on Posidonia Oceanica.

The increase in water temperature due to climate change.

WM implements a series of actions that aim to mitigate the human impact on the ecosystem marine and protect the Posidonia oceanica

You can make the difference

Become an official collaborator of Waving Meadow and disseminate the principles of sustainability to contribute directly or indirectly to the conservation of Posidonia and the marine environment.