Wikipedia
Plastisphere is a term used to refer to ecosystems that have evolved to live in human-made plastic environments.
Plastic that has made its way into marine habitats has been found to host various microorganisms. The hydrophobic nature of plastic surfaces stimulates rapid formation of biofilms, which support a wide range of metabolic activities, and drive succession of other micro- and macro-organisms. A recent study identified more than 1,000 species of bacteria and algae attached to microplastic debris, including members of the genus Vibrio, a genus which includes the bacteria that cause cholera and other gastrointestinal ailments. Some of these bacteria glow and it is hypothesized that this attracts fish that eat the organisms colonizing the plastic, which then feed from the stomachs of the fish.
Plastic pollution provides a more durable "ship" than biodegradable material for carrying the organisms over long distances. This long distance transportation can move microbes to different ecosystems and potentially introduce invasive species as well as harmful algae. The microorganisms found on the plastic debris include autotrophs, heterotrophs and symbionts. The ecosystem created by the plastisphere differs from other floating materials that naturally occur (i.e., feathers and algae) due to the slow speed of biodegradation and other different conditions.
Some of the organisms are thought to accelerate the biodegradation of plastic materials into potentially hazardous chemicals. This could be potentially advantageous though, as scientists may be able to utilize the microbes to break down plastic that would otherwise remain intact longer. On the other hand, as plastic is broken down into smaller pieces and eventually microplastics, there is a higher likelihood that it will be consumed by plankton and enter into the food chain. As plankton are eaten by larger organisms, the plastic may eventually accumulate in fish eaten by humans.
In addition to microbes, insects have come to flourish in areas of the ocean that they previously could not. The sea skater, for example, has been able to reproduce on the hard surface provided by the floating plastic.