What It is and his environmental importance


Learn about the biology of this species of marine plant


Interactions with the environment and other organisms

Key Figures


More than 50 species of fishes (including many traded commercial species) live inside the Posidonia habitat. The role of nursery is highly important for many species. It is a refuge and breeding place for more than 400 plant species and 1,000 animal species.


Seagrasses are able to fix as much carbon as the forest (more than 5 t equivalent CO2 per ha per yr.) and 20 to 25 % is trapped in the meadow for thousands of years (major carbon sink).
Carbon stocks in the dead meadows are 10 times higher than the stock present in the forest soil


2.5 m height of dead meadows takes 4000 years of history.


Every year, Posidonia seagrasses absorb for 0,6% of CO2 emissions of the Mediterranean countries, but this rate can be higher locally (Tunisia = 15-20 % ; Corsica = 14,4%).

posidonia nacra


It helps to preserve the beaches: The Posidonia beds decrease by 20 % the power of the swell.


The economic value of Posidonia Habitat is highly important and is estimated around 50 000 euros / ha / year. Many millions of euros are locally spent every year to protect and manage Posidonia areas.


The growth of the dead meadows is around 1 mm per year (1 m per century maximum). Once destroyed, it cannot be recovered.