Sources and Pathways of Marine Litter

Plastic pollution is a global transboundary threat to the planet's marine resources. Tracking pollution is crucial to implement effective marine management strategies on coastal and island regions, where mismanaged plastics are most at risk of entering the ocean. However, the uncertainty of sources and pathways of marine litter poses a major challenge to the assessment of marine pollution. This chapter reviews the principal sectors and human activities contributing to plastic pollution, the mechanisms by which plastic enters the ocean, and some possible drivers of marine litter, including the growing role of coastal tourism on small developing islands. It also outlines future directions for meaningfully integrating research, material accounting, and prevention actions to mitigate the infiltration of plastic pollution in the marine environment, via proper monitoring, assessment, and reporting on plastic material flows from source to sink.