Marine litter spatiotemporal trends and hazards along the largest enclosed inland water body in the world
摘要
Marine litter (ML) has ubiquitous occurrence and severe environmental impacts, amplified in highly urbanized areas. This study provides the first year-long assessment of ML along the Iranian Caspian Sea coast. From January to December 2022, monthly surveys were conducted across 12 beach sites, resulting in the collection and classification of 15,389 items. The application of four pollution indices enabled a multidimensional assessment of contamination levels and potential hazards. Beaches were clean, reaching dirty levels in the winter, possibly due to harsher hydrodynamic forces and vacation periods. Plastics were the most prevelant material (74.2%), with very high abundance (PAI = 8.40 ± 5.83). Cigarette butts (CBs) were the prevalent item (9.0%), with very high potential pollutants leakage (CBPI = 8.5 ± 18.6). Conversely, a low occurrence of hazardous items was observed yearly. Areas with higher human modification levels had more ML, underscoring the role of urbanization in driving contamination. These results emphasize the urgent need for regionally tailored waste management, monitoring protocols, interventions and stricter pollution control policies to curb the escalating litter impacts.