Lagrangian Particle Tracking of Floating Marine Macro-Litter in the Mediterranean Sea (August 2023 – December 2024)

This dataset contains monthly gridded outputs from ensemble Lagrangian particle tracking simulations of Floating Marine Macro-Litter (FMML) in the Western Mediterranean and Adriatic Seas, derived from systematic shipboard observations collected during the LIFE Conceptu Maris Project (LIFE20 NAT/IT/001371). Simulations were performed using the Parcels / plasticparcels framework, forced by daily sea-surface currents from the Copernicus Marine Service Mediterranean reanalysis (1/24° resolution) and ERA5 10-m winds. Virtual particles were initialized from observed FMML densities aggregated onto a 5 × 5 km EEA reference grid and tracked over a 150-day rolling window using an 18-member ensemble strategy (three release dates per month). The dataset provides two complementary diagnostics on a regular 0.05° × 0.05° grid: (1) monthly frequency-of-occurrence of FMML at the sea surface, and (2) monthly frequency of FMML coastal deposition. These outputs support probabilistic assessment of litter transport hotspots, seasonal accumulation patterns, and potential exposure risk for marine megafauna and protected coastal areas across the Mediterranean basin. Temporal coverage: January 2024 – December 2024 Spatial coverage: Western Mediterranean Sea and Adriatic Sea Format: NetCDF (.nc); supporting figures in PNG Related publication: Bravo et al. (in preparation), Frontiers in Marine Science Funding: This work was carried out within the framework of the LIFE CONCEPTU MARIS Project (LIFE20 NAT/IT/001371). The underlying observational data (ferry FMML observations used to seed the simulations) are not included here and can be made available via personal request to the providers (our co-authors).