Spatial distribution and hazard assessment of plastic-dominated marine litter along the Saudi Arabian Gulf Coast

This study evaluates the spatial distribution and potential hazards of plastic-dominated marine litter along the coast of the Arabian Gulf of Saudi Arabia by integrating field surveys, pollution indices, and hydrodynamic modeling at eleven coastal beaches. The litter density ranged from 0.45 ± 0.13 to 6.81 ± 1.32 items/m², with an overall mean of 1.57 ± 1.98 items/m². The Central Arabian Gulf coast region of Saudi Arabia exhibited the highest mean litter density (3.85 items/m²), followed by the Northern (3.62 items/m²) and Southern (2.82 items/m²) regions. Plastics were the most dominant litter type across all sites (86.58%), while other litter contributed only minor fractions. Beach floor cleanliness was evaluated using the Clean Coast Index (CCI), General Index (GI), Pollution Load Index (PLI) and Hazardous Items Index (HII). The GI and CCI results indicated that none of the surveyed beaches were classified as “very clean”, while PLI values suggested moderate but non-critical pollution levels. HII values showed considerable variability, with several beaches falling under Risk level II (1–4), suggesting moderate hazardous risks. Hydrodynamic modeling (MIKE 21) revealed that litter transport and accumulation were mainly driven by surface currents, tides, and wind, leading to a dominant southward transport. This study provides the first spatially explicit baseline of beach litter along the Saudi Arabian Gulf coast, providing critical insights to support evidence-based monitoring. Our findings directly contribute to the achievement of UN SDG 12 (Responsible Consumption and Production), SDG 13 (Climate Action), and SDG 14 (Life Below Water) by providing high-resolution data necessary to mitigate plastic pollution and protect coastal ecosystems, aligning with the environmental goals of Saudi Vision 2030.