The green lung of the Mediterranean
The Neptune grass (Posidonia oceanica) is an endemic marine plant of the Mediterranean, which forms extensive undulating underwater meadows.
These meadows provide shelter and food for a wide variety of marine species.
It is important to note that Neptune grass is a higher plant, not an alga, and plays a fundamental role in the balance of coastal ecosystems.
A key ecosystem of the Mediterranean coastline
Neptune grass meadows are one of the most characteristic communities of the Mediterranean coastline. They develop on gently sloping seabeds, preferably sandy, in areas sheltered from strong waves, at depths ranging from just below the surface to 35 metres.
An ecosystem that sustains life
Neptune grass produces a large amount of organic matter and oxygen.
It is estimated that 1 m² of leaves can generate up to 10 litres of oxygen per day, significantly enriching other marine ecosystems.
Furthermore, in many bays and beaches, Neptune grass forms natural reefs that help prevent coastal erosion and the disappearance of beaches.
Threats and the need for conservation
Neptune grass meadows are currently in decline due to:
- Pollutant discharges
- Port construction
- Illegal trawl fishing
- Aquaculture
- Boat anchoring
- Invasion of exotic species
Protecting Neptune grass is essential to conserving marine biodiversity, maintaining healthy beaches and ensuring the quality of Mediterranean waters.
A refuge of great biodiversity
Neptune grass leaves serve as a substrate for numerous organisms, including both algae and animals, especially bryozoans and hydroids, forming the well-known epiphytic felt.
They also shelter a great diversity of fish and invertebrates, which use this habitat as a feeding, shelter, mating and breeding ground.
The associated sediment also allows the development of bivalve molluscs and numerous marine worms.
These meadows function as nursery, feeding and shelter zones, making them essential for the renewal of marine populations.
