Posidonia meadow community

The Neptune grass meadows fringing the shallows at Cap de Cavalleria are ancient and extremely slow-growing — individual meadows can be thousands of years old. They are one of the most important marine ecosystems in the Mediterranean: producing oxygen, stabilising sediment, and providing nursery habitat for dozens of commercial fish species. Posidonia is a protected species throughout the EU and a key indicator of seawater quality.