What is a Garbage Patch?
A garbage patch is a popular name for concentrations of marine debris (mostly small pieces of floating plastic) that accumulate across the more stagnant central parts of the large gyres in the ocean basins. The central regions of ocean basins are areas of convergence and downwelling, so trash from sources on land and sea are carried long distances by currents, much of it ending up in a convergence zone garbage patch. The largest garbage patch is in the north Pacific Ocean (Figure 9.42). Garbage is generally quite hazardous to sea life.
(See NOAA's Great Pacific Garbage Patch website.)