Marseille's Seagrass Recovery Driven by Pollution Control Measures

The resurgence of Posidonia oceanica in Marseille is attributed to the significant reduction of organic matter and pollutants following the establishment of a wastewater treatment plant in 1987. This shift has allowed for natural recovery, with seagrass meadows expanding autonomously, presenting a cost-effective example of passive restoration compared to traditional seeding methods.

Monitoring data from the French Water Agency shows a decrease in heavy metals and nitrogen, which previously contributed to harmful algal blooms. Recovery of these meadows is vital for regional biodiversity and ecosystem services, such as carbon storage and shoreline protection, aligning with the EU's Marine Strategy Framework Directive goals.