The centre of the North Pacific Gyre is relatively stationary (the area it occupies is often referred to as the horse latitudes) and the circular rotation around it draws waste material in. This has led to the accumulation of flotsam and other debris in huge floating 'clouds' of waste, leading to the informal name The Great Pacific Garbage Patch or Eastern Garbage Patch. While historically this debris has biodegraded, the gyre is now accumulating vast quantities of plastic. Rather than biodegrading, plastic photodegrades, disintegrating in the ocean into smaller and smaller pieces. These pieces, still polymers, eventually become individual molecules, which are still not easily digested. The photodegraded plastic can attract pollutants such as PCBs. The floating particles also resemble zooplankton, which can lead to them being consumed by jellyfish, thus entering the ocean food chain. In samples taken from the gyre in 2001, the mass of plastic exceeded that of zooplankton (the dominant animalian life in the area) by six times.
Occasionally, shifts in the ocean currents release flotsam lost from cargo ships into the currents around the North Pacific Gyre, leading to predictable patterns of garbage washing up on the shores around the outskirts of the gyre. The most famous was the loss of approximately 80,000 Nike sneakers and boots from the ship Hansa Carrier in 1990: the currents of the gyre distributed the shoes around the shores of British Columbia, Washington, Oregon, and Hawaii over the following three years. Similar cargo spills have involved tens of thousands of bathtub toys in 1992 and hockey equipment in 1994. These events have become a major source of data on global-scale ocean currents. Various institutions have asked the public to report the landfall locations of the objects (trainers, rubber ducks, etc.) that wash up as a method of tracking surface waters' response to the deeper ocean currents.
For several years ocean researcher Charles Moore has been investigating a concentration of floating plastic debris in the North Pacific Gyre. His study indicates that ocean currents have added to the mass until it is now about the size of Texas. Many of these long-lasting pieces wind up in the stomachs of marine birds and animals.
Bottle caps and other plastic objects are visible inside the decomposed carcass of this Laysan albatoss on Kure Atoll, which lies in a remote and virtually uninhabited region of the North Pacific. The bird probably mistook the plastics for food and ingested them while foraging.