Colonization of Plastic Marine Debris

The call for research concerning microbial interactions with marine microplastics has reached a decadal milestone, leaving scientists with not only novel insights into this field of investigation but also many unanswered questions. This chapter reflects on this decade of discovery with respect to the "Plastisphere" that refers to the thin layer of life that colonizes the outside of plastic debris, with a focus on the microscopic life that colonizes plastics in marine systems. It revisits the state of knowledge regarding the Plastisphere in the context of the Known, Unknown, and Unknowable. Early studies concentrated on bacterial members of the Plastisphere, but recently, there is greater recognition that eukaryotes are important members of this ecosystem and increasing numbers of studies are including them. Microbial consortia, as well as symbiotic, parasitic, and predator–prey relationships, undoubtedly play a role in shaping Plastisphere community structure and function.