Posidonia oceanica: Regenerating underwater forests in the Gulf of Naples

People often confuse Posidonia oceanica with seaweed. However, it is a true sea plant, it has roots, stems, and leaves, just like plants on land. Found exclusively in the Mediterranean Sea, Posidonia oceanica covers large areas of the seabed, forming dense and vibrant meadows known as seagrass Posidonia meadows. These underwater meadows are often called the "lungs of the sea" because of the essential role they play in marine ecosystem protection.

Think of them as underwater forests that support the health of our oceans. They offer shelter and food to a wide variety of marine species, including fish, crustaceans, mollusks, and even endangered organisms. 

These meadows improve water clarity, protect coastlines from erosion, and absorb significant amounts of carbon dioxide, making them key allies in fighting climate change. In regions like the Gulf of Naples, where biodiversity is rich and the Naples weather offers ideal conditions, these meadows thrive and contribute immensely to both environmental stability and coastal beauty.

What are the threats and benefits of the Posidonia oceanica? 

In recent decades, seagrass Posidonia has drastically declined due to various human pressures:

• Bottom trawling: damages the seabed and uproots the plants
  
  
• Boat and yacht anchoring: tears out large portions of the meadows
  
  
• Pollution: degrades water quality and hampers photosynthesis
  
  
• Coastal development: alters currents and disrupts sediment flow
  
  

These threats reduce water clarity, limit the sunlight necessary for photosynthesis, and directly damage the plants. The result? A chain reaction harms the whole marine ecosystem. It affects not just Posidonia but also all species that rely on it. This includes mollusks, fish, crustaceans, and sponges.

And yet, Posidonia oceanica meadows provide irreplaceable ecosystem services:

• They are home to 20–25% of all marine species in the Mediterranean, including endangered ones.
  
  
• They produce oxygen and absorb large amounts of CO₂, playing a key role in climate mitigation.
  
  
• They reduce wave energy and protect coastlines from erosion, acting as a natural barrier.

Beached Posidonia is not waste, it’s a natural phenomenon

When we see dark, fibrous clumps along the shoreline, we often assume they’re dead algae. Actually, beached Posidonia oceanica is a completely natural plant material with essential ecological value.

Currents and waves carry dead Posidonia leaves ashore, forming accumulations called banquettes. Far from being a nuisance, banquettes play a key role in coastal protection:

• They prevent erosion by acting as a natural buffer, absorbing wave energy.
  
  
• They trap sand, helping maintain beach stability.
  
  
• They support coastal biodiversity by creating microhabitats for small marine organisms and insects.

PosiFARM: A regeneration project in the Gulf of Naples

Posidonia oceanica meadows are declining quickly. Therefore, new and clear actions to restore and maintain balance in the marine environment are very important.

Here’s where PosiFARM’s mission comes into play. A project led by the Marine Protected Area “Parco Sommerso di Gaiola,” its managing body CSI Gaiola Onlus, and the Anton Dohrn Zoological Station.

The project cultivates seagrass Posidonia from its fruits, known as "sea olives," which currents carry ashore. Special tanks hold and grow these fruits. and helps young seedlings get stronger in a controlled space before they go back into the sea.

The typically mild Naples weather, with stable temperatures and abundant sunlight for much of the year, greatly supports these early growth stages, creating optimal conditions for the successful regeneration of Posidonia oceanica.

In parallel, project teams directly sow some seeds into the seabed of the Gaiola Park in carefully selected areas based on their potential to promote root anchoring and meadow growth. By breathing life back into the seabeds of Posillipo, this initiative revives marine biodiversity while reinforcing wider commitments to ocean protection and the resilience of our coastlines.

How to support these projects with Green Future Project

Green Future Project offers innovative tools to support the regeneration of seagrass Posidonia and protect the Mediterranean marine ecosystem.

Through an advanced, transparent digital platform, businesses and organisations can directly fund high-impact environmental projects. Our interactive dashboard enables you to monitor the health of Posidonia oceanica meadows in real time and access verified scientific data that is geolocated and continuously updated.

This level of transparency ensures a real, measurable commitment aligned with sustainability principles, offering a credible alternative to greenwashing.

To make communicating your impact even easier, you can embed our customisable widget into your website. This widget displays updated metrics, project visuals, and tangible progress, engaging customers, employees, and stakeholders.

With Green Future Project, supporting ocean protection means joining a transparent network of value where every contribution makes a real difference on the ground.