“Plastics in daily use are generally assumed to be quite stable,” said study lead researcher Katsuhiko Saido, Ph.D. “We found that plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future.”
"Plastics contain many of the same kinds of atoms as other objects. But in plastics, these atoms are linked to one another in more complicated ways. Bacteria can't decompose plastics because they can't break the links. Slower processes can break plastics down. But
these processes can take decades or even centuries to do the job".