The 'North Pacific Gyre' (also known as the 'North Pacific Subtropical Gyre') is a swirling
vortex of ocean currents comprising most of the northern
Pacific Ocean.
The North Pacific
Gyre is located between the
equator and 50º N
latitude. It comprises the clockwise circular pattern of the prevailing
ocean currents: the
North Pacific Current to the north, the
California Current to the east, the
North Equatorial Current to the south, and the
Kuroshio Current to the west. It occupies an area of approximately ten million
square miles (34 million km²).
Waste
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.
[1] 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 a factor of six.
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.
[2]
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.
[3]
References
★
UNEP: World's Largest Landfill (pdf)
★
Trashed: Across the Pacific Ocean, plastics, plastics, everywhere
★
ACF: Plastics in the Plankton
★
CNN: How sneakers, toys and hockey gear help ocean science
★
The Problem with Plastic: Waves of Junk Are Flowing Into Food Chain
★ C. J. Moore, S. L. Moore, M. K. Leecaster and S. B. Weisberg (December 2001). "A Comparison of Plastic and Plankton in the North Pacific Central Gyre", ''Marine Pollution Bulletin'' '42' (12), 1297-1300.
★
"Plastic trash vortex menaces Pacific sealife: study" Reuters article from 11-5-2006
★
Animated Pacific trash vortex showing drift of ocean pollution
★
Plastic Turning Vast Area of Ocean into Ecological Nightmare
★ Oliver J. Dameron, Michael Parke, Mark A. Albins and Russell Brainard (April 2007). "Marine debris accumulation in the Northwestern Hawaiian Islands: An examination of rates and processes", ''Marine Pollution Bulletin'' '54' (4), 423-433.
External links
★
LA Times special Altered Oceans
★
Algalita Marine Research Foundation accounts of the North Pacific Gyre
★
Google video: A world of unknown plastic pollution
★
Best Life Magazine: Plastic Ocean
See also
★
Yellow Thing: catamaran used by
Greenpeace to sample ocean garbage
★
Greenpeace facts about the North Pacific Gyre