Posidonia, or Neptune’s grass, is a plant that can be found exclusively in the Mediterranean Sea. It is a real plant in every sense, equipped with roots, stem, leaves, flowers and fruits – and therefore not a seaweed. It is a herbaceous plant, which propagates using sexual reproduction through the fertilization of flowers, the ripening of fruits, and seeds. Posidonia and its meadows are of vital importance for the life of the sea. Specifically protected by international and national regulations, they are in danger mainly due to illegal trawling and careless anchoring of vessels.
Oxygen for the sea!
Like every plant, posidonia takes advantage of photosynthesis, the mechanism that converts sunlight to release oxygen, up to 20 liters of oxygen per day per square meter of meadow. The water where posidonia grows must therefore be clear, so that sunlight can reach it.
Just like trees, in autumn the posidonia’s leaves begin to fall off. Completely brown, they wash up on the coast, sometimes forming large drifts called banquettes. Their presence indicates the good quality of marine waters.