Breaking News: Marseille Utilizes Posidonia to Combat Coastal Erosion
Protected Since 1988, Posidonia Now a Tool Against Coastal Erosion
The “Treasury of the Mediterranean,” Posidonia oceanica, a vital seabed plant, has been utilized by the city of
Marseille in an innovative approach to combat coastal erosion. Protected since 1988, Posidonia serves as both a sanctuary for marine life and a carbon sink. However, today, it is emerging as a defense mechanism against the destructive forces of swell and currents.
Three-Year Pilot Project with Encouraging Results
This spring, Marseille embarked on a three-year pilot project testing the use of dead Posidonia plants washing up on beaches. Utilizing snubbers, teams have created layers known as “mille-feuille de posidonies;” alternating sand, pebbles, and Posidonia leaves. The goal is to secure the sand, preventing it from being washed away by waves.
Carbon Sequestration and Beach Stabilization
According to Marseille city officials, a cubic meter of Posidonia leaves can fix between 10 to 100 kg of sand. This groundbreaking technique promises to enhance maritime life, sequester carbon, and stabilize beaches. Currently, four beaches—Bonnevein, Borély, and the Prophet—are under experimentation until 2027.
Evergreen Value of Posidonia
Posidonia oceanica has historically played a critical role in the health of the Mediterranean ecosystem. Beyond coastal management, its complex seam-web structure mitigates ocean currents and supports a vast array of marine flora and fauna. Derived from the Greek god of the sea, Poseidon, Posidonia’s legacy underscores its enduring importance in Europe’s maritime heritage.
