Project at a glance

Background

Posidonia oceanica is a seagrass endemic to the Mediterranean Sea. Its meadows cover only a small part of the seabed, yet they are essential to the balance of the coastal marine environment: they produce oxygen, store blue carbon, protect coastlines and provide shelter and habitat for a great many organisms.

Since the 1950s, meadows have been declining under combined human pressures, including pollution by persistent and emerging organic contaminants (pharmaceuticals, personal care products, endocrine disruptors, flame retardants) that conventional wastewater treatment plants cannot remove. Knowledge of their effects in the Mediterranean is still limited.

The Secche di Tor Paterno MPA is the only fully submerged marine protected area in the Mediterranean, with no direct boundary to the coastline. Its roughly 6-hectare meadow grows on rock and matte, in an area free of physical disturbance and influenced by Tiber waters: an ideal natural laboratory for this study.

Objectives

• Objective 1 – Environmental status. Assess the good environmental status of the Posidonia habitat under the Marine Strategy Framework Directive (2008/56/EC), Descriptor 1 “Biodiversity”.
• Objective 2 – Associated communities. Test innovative methods based on associated communities, consumers and predators to assess how the meadow ecosystem functions.
• Objective 3 – Contaminants. Identify regulated and emerging contaminants in biotic and abiotic matrices and assess their accumulation and effects on the plant and associated communities.
• Objective 4 – Governance and participation. Strengthen coordination among responsible bodies and raise awareness among MPA users: small-scale fishers, recreational anglers and diving centres.

Activities

• Meadow mapping. Acoustic (MBES) and ROV visual surveys down to 35 m depth to update the habitat map.
• Meadow condition. Sampling by scientific divers at 2 sites with 3 stations each.
• Associated communities. Non-destructive visual census of megabenthic fauna on the rhizomes and of the fish assemblage, including the nursery function for juveniles.
• Analysis of 37 compounds (16 PAHs, 17 pharmaceuticals and personal care products, 4 endocrine disruptors) in water, sediment and Posidonia, against European environmental quality standards (MSFD Descriptor 8).
• Stakeholder engagement. Training, awareness-raising and Citizen Science initiatives with small-scale fishers, diving centres and underwater tourism associations.

What we will measure

Expected outcomes

• An updated, detailed map of the Posidonia meadow in the MPA.
• Assessment of ecological status and contaminant accumulation under MSFD Descriptors 1 and 8.
• Validation of oceanica and its associated communities as bioindicators of chemical contamination and environmental quality.
• Data supporting MPA Management Plans and conservation and restoration measures, in line with the EU Nature Restoration Regulation (2024/1991).
• Wider adoption of sustainable-use practices and greater involvement of local operators.

The project is co-funded under the EMFAF (FEAMPA).