A baseline study of macro, meso and micro litter in the Belize River basin, from catchment to coast.

This article focuses on the investigation of macro, meso, and microplastic litter distribution along the Belize River basin and adjacent coastal areas, adapting the North-East Atlantic OSPAR beach litter monitoring protocol to local conditions. The study found that plastic constituted approximately 77.3% of litter items, with an increasing litter load observed from inland river catchments toward the coast, including rises in plastic pieces and fishing-related debris. Microplastics were detected in all sediment samples (ranging from 200 to 6,500 particles per kg dry sediment) and in 36% of sampled riverine fish (Cichlasoma synspilum), indicating contamination of freshwater biota. These baseline data provide critical evidence to support the development and evaluation of Belizean legislation aimed at reducing marine litter and highlight the importance of region-specific monitoring to inform effective waste management policies.