Economic role 

Posidonia oceanica meadows help to maintain coastal equilibrium, thus ensuring that economic activities related to these ecosystems are maintained (it should be noted that these economic activities are very important in many coastal countries like Tunisia):

- They constitute a shelter for many fished species such as the mullet (a species heavily exploited by the Tunisian fishing industry) thus ensuring the maintenance of fishing activities (activities constituting about 10% of the Tunisian GDP (Fig.12)).     

- It allows the development of tourism and seaside activities (activities representing about 5% of the Tunisian GDP (Fig.13)) by preserving the quality of the water and protecting the beaches against erosion.