In July 2025, a major environmental project to restore seagrass meadows of Posidonia was completed in the Ses Salines natural park, located between Ibiza and Formentera. The initiative, organized by Bluewave Alliance with the support of Isdin and the Vellmarí Association, saw the planting of 37,200 new Posidonia plants.
The seagrass restoration efforts lasted several months and included 59 outings at sea. Forty-nine volunteers participated in the project, including marine biologists, diving instructors, and teenagers enrolled in the Vellmarí Dive Camp educational program. The program not only teaches the basics of diving but also fosters a sense of responsibility for the marine environment among young people.
Fragments of Posidonia rhizomes, similar to cuttings used in land-based gardening, were used for planting. Each diver formed small bundles of plants, secured them on special supports, and pressed them into the sea floor to ensure the roots anchored securely and could take hold. This approach achieved an average density of 616 plants per square meter — a figure consistent with healthy seagrass meadows in the restoration area.
Since 2023, the project has already restored over 60,000 Posidonia plants. Participants note that these initiatives not only help increase the area of seagrass meadows but also enable the monitoring of growth dynamics, branching, and colonization by new species, thereby boosting the region’s biodiversity.
Posidonia is a unique marine plant found only in the Mediterranean Sea. It plays a crucial role in maintaining the ecosystem: providing shelter and food for numerous marine species, oxygenating the water, stabilizing the seabed, and protecting the coastline from erosion. In addition, each square meter of Posidonia can absorb ten times more carbon dioxide than tropical forests, making it a vital element in the fight against climate change.
However, over the past decades, more than 30% of Posidonia meadows in the Mediterranean have disappeared. The main causes are illegal anchoring, trawling, coastal development, and pollution. Restoring and protecting the remaining meadows is an urgent priority, as Posidonia can be destroyed quickly, but its recovery takes decades or even centuries.
The project in Ibiza and Formentera combines a scientific approach with educational programs. In addition to planting, specialists conduct regular monitoring: they assess how well the new plantations are taking root, how their density changes, and what species appear in the new meadows. This comprehensive approach not only restores the ecosystem but also encourages locals and young people to develop a responsible attitude toward the sea.
Organizers emphasize that the success of such initiatives is only possible through the combined efforts of scientists, business, and society. The restoration of Posidonia is an example of how joint actions can help restore the health and beauty of the Mediterranean Sea, as well as ensure its sustainable future.
