BEACH CONTAMINATION BY MARINE LITTER: APPLICATION OF DPSIR (DRIVER, PRESSURE,

Marine litter, that is solid materials deliberately or accidentally released into marine and coastal environments, is a growing issue both at local and global scale. In particular, litter accumulation on beaches represents a relevant problem in touristic coastal areas. The DPSIR framework, already applied to tackle other environmental issues, can help in analysing the origin, impact, and possible solution of material stranded on the beach allowing a holistic approach in the “one health” perspective. It was applied in a popular sandy bathing location in the North-Western Tuscany (Italy). Information and data on origin and fate of beach-stranded material as well as existing local strategies were retrieved from a stakeholders’ network. In summer 2020, a monitoring campaign was performed to evaluate the sanitary state of the shoreline and the impact of this material on coastal habitat. In a 7-year period (2014-2020), a mean amount of 1.548,3 tons of beach-stranded material have been collected and treated to separate sand (55%), organic green fraction (31%), and anthropogenic debris (2%), while 12% weight-loss was attributable to evaporation. Analysis of historical environmental data revealed that shoreline accumulation of this material was associated with low atmospheric pressure, medium-strong winds, and storms. Preliminary monitoring data showed that the green fraction was mainly represented by wood and terrestrial plants with little quantity of the seagrass Posidonia oceanica, while most of the anthropogenic debris was rubber and metal. Microbial pollution of beached material was at least one order of magnitude higher than the surrounding environment (sand and seawater) for total coliforms, Escherichia coli, intestinal enterococci, and total fungal load. Overall, our results indicate a potential impact of beach-stranded material in this coastal area, with possible health risk for human population. The instruments already in place for the management of beached material, although consistent, could be further improved.

Accumulation of stranded biomass (banquettes) is a natural phenomenon, mostly frequent along Mediterranean coast for the presence of extensive Posidonia oceanica meadow Italian regulation allowed a series of management methods • On-site maintance • On-site burial • Displacement of the deposit • Agronomic use • Permanent removal and disposal (Ministerial Memorandum No. 8838

BACKGROUND: Composition of beach-stranded material
In recent year, the quantities of anthropogenic material mixed to standed biomass is increasing, owing to the global issues of marine litter, affecting all the sewaters of the world Marine litter is commonly defined as "any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment." (UNEP, 2009) The presence of beach litter hampers environmental-friendly management options of stranded biomass and their reuse.
In Italy, more than 50% of the beached biomass reaches the landfill, mainly because of the presence of several anthropogenic litter items Quantities of beach-stranded material and relationships with environmental variables Data sources: analysis of data acquired by stakeholders Accumulation of debris occurs mainly during periods of bad weather (minimum atmospheric pressure), with medium-strong winds (max = 10.7 m/s) In a 7-year period, an annual average of 1550 tons of beach-stranded material has been collected along the 5 km coastline under investigation.

Microbiological analysis of beach-stranded material
Beach-stranded material: Beach litter High amount of anthropogenic material has been counted with an average of 380 items/100m. Plastic was the most prevalent litter item found on the beach, followed by rubber and metal

Beach-stranded material: Biomass
During a monitoring survey on Sept. 2020, biomass was mainly represented by wood (mainly little size pieces < 5 cm) and terrestrial plants. Little quantity of the seagrass Posidonia oceanica was also detected. 8

Quantification of the state (3)
Data sources: field study

Safety and Health impact Environmental impact
The analysis of the "state" subjected to pressures allowed to identify the following impacts on economy, human health, and environment

Analysis of the responses already in place
To avoid land-based debris and biomass to reach the seawaters, a floating barrier has been posed near the river mouth. However, some technical problems hamper the effectiveness of this measure

Analysis of the responses already in place
▪ Organization of sensibilization campaigns to promote waste reduction and correct separate collection of waste; ▪ Coordination of beach-cleanup activities along shoreline (but also along watercourses) with a double aims: removing trash and acquiring scientific information on litter (physical characterization).
In the study area, some strategies are already in place to remove or minimize the problem of beach contamination. However, such measure can be enhanced, and other ones can be suggested.

Improvement of the measures for litter management
▪ Improvements of floating barrier to stop litter along watercourse by a periodical maintenance of the barrier and cleaning of the accumulated residues ▪ In situ reuse of green fraction obtained from treatment of beach-stranded material (i.e., production of bio-containers) 13

Formulation of further possible responses
The accumulation of beach-stranded material represents a complex environmental problem, causing environmental, sanitary, social, and economic impacts.
Currently, such issue has not yet been tackled using an integrated approach and data related to beach contamination are often non-homogeneous and fragmented

FINAL REMARKS
For the first time, beach contamination has been structured following the DPSIR framework and the conceptual model has been applied to a concrete case study. The DPSIR has been used: ❖ to analyze drivers, pressures and state of this specific coastal issue, integrating filed monitoring and data collected by a local stakeholders' network; ❖ to describe the management responses already in place in order to valorize them and to suggest further management options to improve the current situation.
-Municipality of Pietrasanta (Italy) -waste management company -planning authority on reclamation Fondazione Cassa di Risparmio di Lucca We wish to thank for data sharing for financial support