Cleaner Seas Spark Remarkable Seagrass Recovery

France has restored marine ecosystems off Marseille by reducing pollution, allowing vital seagrass meadows to recover naturally and strengthen biodiversity and carbon storage.

“We observed exceptional recovery of the meadow in the Bay of Marseille,” said Patrick Astruch, research engineer at GIS Posidonie.

After decades of decline, Neptune grass coverage rose from 47% to 94% in one study area and from 6% to 81% in another between 1986 and 2025. The turnaround followed wastewater treatment improvements and stronger environmental protections introduced in the late 1980s, removing key pressures on the ecosystem. This seagrass, which supports up to one quarter of Mediterranean marine species and stores significant carbon, demonstrates that simply reducing pollution can enable large-scale natural recovery, offering a cost-effective model for restoring oceans worldwide.