The oceans contain large amounts of microplastics, particles that are less than 5 mm in size. In parts of the Baltic Sea, the concentration of microplastics can be as much as 3,300 particles per cubic meter. The microplastics end up in aquatic environments through industrial or domestic sewage and littering. Because they are difficult to degrade, they can be persistent in the ecosystem and affect many aquatic organisms. Read this story
