Italia-Croatia

20/04/2026

What many beach users perceive as “seaweed” or beach waste is often part of one of the most valuable natural systems in the Mediterranean. Along Adriatic and Mediterranean coasts, leaves and fibres of Posidonia oceanica may accumulate on the shoreline, forming natural deposits known as banquettes.

Far from being a sign of neglect, these deposits are evidence of a functioning marine and coastal ecosystem.

Posidonia oceanica is not an alga, but a marine plant that forms underwater meadows of great ecological value. These meadows provide habitat for many marine species, contribute to oxygen production, support biodiversity and help stabilise sediments. When Posidonia leaves reach the shore, they continue to play an important role.

On beaches, Posidonia banquettes help reduce wave energy, trap sand and limit erosion. They also provide organic matter and shelter for many organisms living in coastal environments. For this reason, their automatic removal for aesthetic purposes can weaken the natural resilience of beaches, especially in areas exposed to increasing pressures from tourism, coastal development and climate change.

Within ASPEH – Adriatic SPEcies and Habitats of coastal areas, the protection of coastal and marine habitats is at the centre of a wider cross-border effort. The project brings together Italian and Croatian partners to develop conservation measures, pilot actions, training activities, awareness campaigns and a joint strategy for the better management of Natura 2000 sites and priority habitats.

The message promoted by ASPEH is clear: a natural beach is not necessarily a “dirty” beach. In many cases, what appears to be waste is actually part of the beach’s own protection system.

Changing this perception is essential for more sustainable beach management. Local authorities, tourism operators, visitors and coastal communities can all contribute by recognising the ecological function of natural deposits and by supporting management practices that balance public use with habitat conservation.

Respecting Posidonia banquettes means respecting the natural processes that protect the coast. It also means supporting a more informed and sustainable relationship with the Adriatic Sea and its fragile coastal habitats.