Each year, Mediterranean coastlines are overwhelmed by tons of Posidonia oceanica, a protected seagrass that washes ashore in huge volumes. While Posidonia is vital to marine biodiversity, its accumulation on beaches is often treated as waste—costly to remove, difficult to manage, and typically sent to landfills, creating methane and disrupting fragile ecosystems.

Each year, up to 30 million tons of Posidonia oceanica wash ashore along Mediterranean coastlines. While essential underwater—stabilizing seabeds and sequestering carbon—once beached, this biomass becomes a serious waste management problem.

Municipalities pay between €100–€300 per ton to remove it, and much of it ends up in landfills—producing methane and violating EU waste directives. But this so-called waste is actually a valuable organic resource.

At Assea Bioenergy, we’ve developed a low-energy, zero-waste process to recycle this biomass into organic compost and soil improvers. Our process includes:

• Pre-sorting and desalination of Posidonia residues
• Aerobic composting under controlled conditions

The result is a certified organic soil improver rich in:

• Organic carbon (20–25%)
• Slow-release nitrogen
• Trace minerals like calcium and magnesium
• A C:N ratio optimized at 15–20:1 for agricultural use

Field trials show that our product:

• Increases soil water retention by 25–30%
• Enhances microbial activity by up to 40%
• Boosts crop yields by 15–20%, especially in arid and degraded soils

The result?
A triple win: cleaner coastlines, healthier soils, and a lower carbon footprint.

What makes us unique is our ability to bridge ocean health with land-based sustainability—all while creating circular value in local economies.

This creates a win-win-win:
✅ Environmental – diverting marine biomass from landfills, reducing GHG emissions, and protecting sensitive marine zones
✅ Agricultural – regenerating soils naturally, reducing synthetic fertilizer dependence
✅ Economic – turning a coastal liability into a local resource, saving municipalities money and creating green jobs

We’re already in partnership with the local Municipal Port Authorities and we estimate that each 1,000 tons of Posidonia we process can:

• Prevent 2,500 tons of CO₂e emissions
• Produce 600 tons of compost
• Restore up to 300 hectares of degraded farmland

At Assea Bioenergy, we’re not just removing waste—we’re redefining its value in a fully circular, marine-to-soil system.

By taking part in our program, a volunteer will participate to the whole process off collection, recycling and production. This way a volunteer will contribute to our mission targets towards sustainability.

Accomodation is provided in a 3 bedroom house villa with 1 bathroom and 1 WC. 

The villa has a breathtaking view with balconies and backyard, and it is located in Pili, a traditional village with natural springs. The house is about 5 km distance from Assea's premises. The house is fully furnished including washing machine and kitchen appliances. 

In the village there are a few restaurants serving traditional greek food and mini markets. 

All volunteers will co-work with Mrs.Apostolia, the founder of the project, and one of the company's Agronomist. Our team is offering full support & equipment, and the volunteers are expected to follow the daily schedule as described in detail below.