Neptune Seagrass - the lungs of the Mediterranean

Many of us see large bundles of black brown long narrow leaves swept ashore normally after a storm. We look at this with disgust and we hope that our beach is cleaned of this dead fauna immediately so we can enjoy our beaches once again. Little do we know that this is one of the most important seagrass we have in the Mediterranean.

This is mainly found in Italy, South of France, Greece, Spain and Malta with the largest colony residing in Italy. This endemic seagrass also known as Posidonia Oceanica or Neptune Seagrass is found in sandy channels around 35 metres below sea level close to the beach and can grow up to 1.5 metres tall and has been around over 80,000 years. This seagrass is of high importance to the ecosystem of the Mediterranean. In fact it is a protected species under the EU Directive 92/43/EEC on the conservation of natural habitats and wild fauna and flora. Why is it so important?

  • It is the habitat for over 350 marine species used for feeding, shelter and breeding

  • It guarantees the quality of sea water

  • Protects beach from erosion

  • Breaks waves and swells

  • Stabilises the seabed

  • It produces around 16 litres of oxygen per day per square metre

However in recents decades almost half of the recorded 276,600 hectares of Neptune Seagrass have been badly effect by various factors that is effecting their growth. This seagrass is key for a healthy Mediterranean Sea. The following factors are leaving a negative impact on this valuable species and is in danger of disappearing in the next few years:

  • Water and sediment enrichment (excessive nutrients mainly due to runoffs from land)

  • Disruption of the sedimentation/erosion balance along the coast

  • Direct destruction by human modifications fo the coastline

  • Degradation by boat trawling and anchoring

  • Increase in salinity in the vicinity of desalination plants

  • Proliferation of invasive algal species

  • Higher sea temperatures

There are many ongoing conservation projects and with the help of the European Union taking place like The MedPosidonia Project finalised in 2008, MEDKEYHABITATS finalised in 2016 and others like Save Posidonia Project in Formentera, POSBEMED throughout various locations the mediterranean and LIFE+ Posidonia in Andalucia.

So when you are snorkeling, diving or boating, please be careful about this valuable species. If we want to keep enjoying our Mediterranean Sea, then please keep a eye and inform others about the importance of the Neptune Seagrass - the Lungs of the Mediterranean.

Dead Posidonia Oceanica swept ashore after a big storm in Malta