GIS mapping of Allochthonous Marine Litter across the Brazilian Amazon Coast

Abstract. The Amazon coast is vulnerable to solid waste pollution, which can lead to the degradation of its ecosystems and affect its biodiversity. The debris that reaches this coast has different origins and sources, with international waste coming from other countries through mainly sea-based sources. Characteristics and dynamics of litter have been studied through monitoring to establish mitigation strategies. However, there is still limited information on international waste in the region, so this work aims to map allochthonous marine litter using geographic information systems (GIS) to monitor its distribution in four municipalities of coast of Pará. The methodology includes the design of a georeferenced ArcGIS Survey123, international waste collection in the field, processing of the litter in the laboratory, and, finally, integrating the data obtained and designing an interactive map viewer. The online dashboard presents descriptive statistics of all data collected on the eight beaches of interest. In total 577 items were collected, and the characterisation led to the identification that the international litter comes mainly from Africa and Asia. There is a high incidence of plastic waste, especially mineral water bottles. The study gives visibility to a problem that affects the socio-cultural and environmental value of the region. The visual presentation of the data provides an engaging and simplified overview of allochthonous litter on beaches in Pará, allowing for adequate dissemination and awareness of international waste dynamics.