Plastic pollution may have unseen and unsuspected effects, directly on the marine ecosystem dynamics. Much of the low-density plastic debris derived from human activity remain on the sea-surface. Thus, they are subject to photochemical degradation, to microbial colonization and degradation, and support biofilm formation.
These linked processes at the ocean's surface may influence ocean-atmosphere dynamics by altering the flux of gases and particles at the air-sea interface, with climate implications.
These ideas have been tested in laboratory (Micro-POSEIDOMM) and field controlled conditions (Meso-POSEIDOMM, mesocosm experiment), and the results so far suggest that plastic accumulation, especially in surface waters, may interfere with the production and consumption of organic material, with implications for the air-sea exchange of gases and the export of organics across the water column.
The problem of plastic pollution needs to be tackled on land. The parallel citizen-science project carried out within POSEIDOMM aimed at promoting public stewardship of local aquatic resources, quantifying the type and quantity of plastic entering our rivers with the aim of reducing the amount of plastic reaching our seas. Efforts to solve the plastic problem require a partnered approach between research institutions, municipalities, educational institutions and citizens that can be achieved through citizen science. Since the starting of the project, POSEIDOMM volunteers have helped removing more than 1500 plastic macro pieces from local waterways preventing them entering the Mediterranean Sea, and performed 152 samplings over 25 sampling sites in the Arno River catchment (Tuscany, Italy). Such project has helped creating an informed community willing and able to participate to environmental management discussion and decisions, with many positive socio-economic impacts at the local level towards higher awareness, participation and public stewardship of aquatic resources.
