The distribution characteristics of marine litter in the intertidal zone of Lvhua Island and its impact on the macrobenthic community structure.

Marine litter typically originates from human discards at sea or enters the ocean through land-based pathways such as surface runoff and natural disasters. The extensive accumulation of plastic litter poses severe threats to marine life. In August 2024, a specialized survey was conducted to investigate the distribution characteristics of marine litter and macrobenthic communities across four intertidal zones on Lvhua Island (XIAO'AO, DA'AO, FANGANG, and SHIZIKENG). The study documented a total of 357 marine litter items, with an average numerical density of 0.27 items/m and a mass density of 27.54 g/m. DA'AO exhibited the highest numerical density (0.38 items/m), while SHIZIKENG had the lowest (0.07 items/m). Regarding macrobenthic communities, the survey recorded 54 species across 13 classes and 7 phyla, predominantly from Rhodophyta and Mollusca. Based on the obtained results, we can conclude that plastic and polystyrene foam litter constitute the primary litter types. The main sources of litter are shipping/fishing activities, followed by other discarded items and human shoreline activities. The litter predominantly consists of large-sized items. Significant variations were observed among sites in species richness, biological density, biomass, and diversity indices. Enhanced monitoring of marine litter on Lvhua Island is required to provide technical support for marine litter remediation and benthic biological resource restoration on the island, offering scientific guidance for the sustainable development of marine resources.