With annual global production of artificial polymersiplasticsjexceeding 400 million tonnes, the oceans are among the areas most affected by plastic pollution. The distribution of plastics in these oceans is influenced by human activities. Plastic pollution is found on beaches, on the surface and, for more than 90%, on the seabed worldwide. Plastic degrades at sea into microplastics or nanoplastics, constituting, together with industrial pellets or primary microplastics, a heterogeneous group of particles, varying in size, shape, colour, chemical composition and density. Little is known about the extent of the impacts caused by marine litter and microplastics. Some of the most important are the entanqlement of organisms, ingestion by organisms, release of contaminants and long-range transport of species. There are also impacts on certain sectors of the economy, including tourism and fisheries, but also risks to navigation and health impacts. In addition to reduction measures based on circular economy, recycling, water purification, selective cleaning and education, global initiativesiUnited Nations Environment Assembly, G7 and G20j, establish a framework within which states must take management measures to achieve a better state of the environment. However, the risks remain high, environmentally, socially, economically and for human health.