Multidisciplinary Approach for Assessment and Management of Posidonia Oceanica Banquettes

The Posidonia oceanica meadows and dead leaf accumulations along the Mediterranean seashores (known as banquettes), are key habitats for coastal marine environments, providing many ecological functions and ecosystems services. Despite their ecosystem services, the banquettes are still perceived as an “obstacle” to tourist and recreational activities, potentially unsafe for humans, trapping marine debris. This negative perception leads to ecologically and economically unsustainable management approaches, mainly removal and disposal in landfill with negative impacts on the environment (e.g. beach integrity alteration, biodiversity reduction) and increasing costs for beach cleaning. Despite their key ecological roles, banquettes are poorly investigated, concerning both their distribution and role as potential sink and source of contaminants (including microplastics). In this framework we investigated the Posidonia banquettes by using a multidisciplinary approach which includes: i) a GIS-based mapping of P. oceanica deposit sites along Italian coasts, and integration of other useful data (e.g. proximity to seagrass meadows, beach utilization, protected areas, etc.); ii) in situ survey of three selected sites; iii) physico-chemical characterization of banquettes samples for microplastic detection. Preliminary results contribute to improve scientific knowledge about the banquette (mapping and monitoring) and provide technical support for sustainable management of “Posidonia beaches”.