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Great Pacific Garbage Patch
From Wikipedia, the free encyclopedia
The Garbage Patch is located within the North Pacific Gyre, one of the five major oceanic gyres.
The Great Pacific Garbage Patch, also described as the Eastern Garbage Patch or the Pacific Trash Vortex, is a gyre of marine litter in the central North Pacific Ocean located roughly between 135° to 155°W and 35° to 42°N and estimated to be twice the size of Texas.[1] The patch is characterized by exceptionally high concentrations of suspended plastic and other debris that have been trapped by the currents of the North Pacific Gyre. Despite its size and density, the patch is not visible from satellite photography.
Discovery
The existence of the Eastern Garbage Patch was predicted in a 1988 paper published by the National Oceanic and Atmospheric Administration (NOAA) of the United States. The prediction was based on results obtained by several Alaska-based researchers between 1985 and 1988 that measured neustonic plastic in the North Pacific Ocean.[2] This research found high concentrations of marine debris accumulating in regions governed by particular patterns of ocean currents. Extrapolating from findings in the Sea of Japan, the researchers postulated that similar conditions would occur in other parts of the Pacific Ocean where prevailing currents were favourable to the creation of relatively stable bodies of water. They specifically indicated the North Pacific Gyre.[3]
The existence of the garbage patch received wider public and scientific attention after it was documented in several articles written by Charles Moore, a California-based sea captain and ocean researcher. Moore, returning home through the North Pacific Gyre after competing in the Transpac sailing race, came upon an enormous stretch of floating debris.
Moore alerted the oceanographer Curtis Ebbesmeyer to the existence of the phenomenon, who subsequently dubbed the region the "Eastern Garbage Patch" (EGP). The area is frequently featured in media reports as an exceptional example of marine pollution.[4]
Formation
Like other areas of concentrated marine debris in the world's oceans, the Eastern Garbage Patch has formed gradually over time as a result of marine pollution gathered by the action of oceanic currents.
The garbage patch occupies a large and relatively stationary region of the North Pacific Ocean bound by the North Pacific Gyre (a remote area commonly referred to as the horse latitudes). The rotational pattern created by the North Pacific Gyre draws in waste material from across the North Pacific Ocean, including the coastal waters off North America and Japan. As material is captured in the currents, wind-driven surface currents gradually move floating debris toward the center, trapping it in the region.
The size of the affected region is unknown, as large items readily visible from the deck of a boat are few and far between. Most of the debris consists of small plastic particles suspended at or just below the water surface, making it impossible to detect by aircraft or satellite images.[5] Estimates on size range from 700,000 km² to more than 15 million km², (0.41% to 8.1% of the size of the Pacific Ocean). The area may contain over 100 million tons of debris.[6] It has also been suggested that the patch may represent two areas of debris that are linked.[7]
Sources of pollutants
It has been estimated that 80% of the garbage comes from land-based sources, and 20% from ships at sea. Currents carry debris from the west coast of North America to the gyre in about five years, and debris from the east coast of Asia in a year or less.[8][9] An international project led by Dr. Hideshige Takada of Tokyo University studying plastic pellets from beaches around the world may provide further clues about the origins of pelagic plastic, including that of the Pacific garbage patch.[10]
Plastic photodegradation in the ocean
Main article: Photodegradation
The Eastern Garbage Patch has one of the highest levels of plastic particulate suspended in the upper water column. As a result, it is one of several oceanic regions where researchers have studied the effects and impact of plastic photodegradation in the neustonic layer of water.[11] Unlike debris which biodegrades, the photodegraded plastic disintegrates into ever smaller pieces while remaining a polymer. This process continues down to the molecular level.
As the plastic flotsam photodegrades into smaller and smaller pieces, it concentrates in the upper water column. As it disintegrates, the plastic ultimately becomes small enough to be ingested by aquatic organisms which reside near the ocean's surface. Plastic waste thus enters the food chain through its intense concentration in the neuston.
Density of neustonic plastics
Despite Charles Moore's description, the eastern garbage patch cannot be characterised as a continuous visible field of densely floating marine debris. The process of disintegration means that the plastic particulate in much of the affected region may be too small to be seen. Researchers must estimate the overall extent and density of plastic pollution in the EGP by taking samples. In a 2001 study, researchers (including Moore) found that in certain areas of the patch, concentrations of plastic reached one million particles per square mile.[12] The study found concentrations of plastics at 3.34 pieces with a mean mass of 5.1 milligrams per square meter. In many areas of the affected region, the overall concentration of plastics was greater than the concentration of zooplankton by a factor of seven. Samples collected at deeper points in the water column found much lower levels of plastic debris (primarily monofilament fishing line), confirming earlier observations that most plastic waste concentrates in the upper parts of the water column.
Impact on wildlife
The floating plastic particles resemble zooplankton, which can be inadvertently consumed by jellyfish. Many of these long-lasting plastics end up in the stomachs of marine birds and animals,[13] including sea turtles, and the Black-footed Albatross.[14] Besides the particles' danger to wildlife, the floating debris can absorb organic pollutants from seawater, including PCBs, DDT, and PAHs.[15] Aside from toxic effects,[16] when ingested, some of these are mistaken by the endocrine system as estradiol, causing hormone disruption in the affected animal.[14]
Cleanup
In 2008, Richard Owen, a building contractor and scuba dive instructor, formed the Environmental Cleanup Coalition to address the issue of the pollution of the North Pacific. The ECC plan calls for modifying a fleet of ships to clear the area of debris and form a restoration and recycling laboratory called Gyre Island.[1][17]
On 1 August 2009 it was announced that Doug Woodring (an ocean conservationist) working in conjunction with the Scripps Institution of Oceanography, would be embarking upon an expedition to the plastic vortex in order to explore, photograph, video and to alert the public to the growing threat of ocean waste. The first ship of the expedition departed California on 2 August with about 30 researchers, technicians and crew members. The 170-foot vessel New Horizon is equipped with a laboratory for on-board research, but scientists also will bring back samples for further study.
The second ship departed on 4 August. In addition to the potential harm to sea life caused by ingesting bits of plastic, the expedition team will look at whether the particles could carry other pollutants, such as pesticides, far out to sea, and whether tiny organisms attached to the debris could be transported to distant regions and thus become invasive species. Aside from conducting scientific research on the impact of the plastic vortex on marine life, the expedition will also experiment with ways to clean up the vortex without harming the marine life in and around it.[18][19]
From Wikipedia, the free encyclopedia
The Garbage Patch is located within the North Pacific Gyre, one of the five major oceanic gyres.
The Great Pacific Garbage Patch, also described as the Eastern Garbage Patch or the Pacific Trash Vortex, is a gyre of marine litter in the central North Pacific Ocean located roughly between 135° to 155°W and 35° to 42°N and estimated to be twice the size of Texas.[1] The patch is characterized by exceptionally high concentrations of suspended plastic and other debris that have been trapped by the currents of the North Pacific Gyre. Despite its size and density, the patch is not visible from satellite photography.
Discovery
The existence of the Eastern Garbage Patch was predicted in a 1988 paper published by the National Oceanic and Atmospheric Administration (NOAA) of the United States. The prediction was based on results obtained by several Alaska-based researchers between 1985 and 1988 that measured neustonic plastic in the North Pacific Ocean.[2] This research found high concentrations of marine debris accumulating in regions governed by particular patterns of ocean currents. Extrapolating from findings in the Sea of Japan, the researchers postulated that similar conditions would occur in other parts of the Pacific Ocean where prevailing currents were favourable to the creation of relatively stable bodies of water. They specifically indicated the North Pacific Gyre.[3]
The existence of the garbage patch received wider public and scientific attention after it was documented in several articles written by Charles Moore, a California-based sea captain and ocean researcher. Moore, returning home through the North Pacific Gyre after competing in the Transpac sailing race, came upon an enormous stretch of floating debris.
Moore alerted the oceanographer Curtis Ebbesmeyer to the existence of the phenomenon, who subsequently dubbed the region the "Eastern Garbage Patch" (EGP). The area is frequently featured in media reports as an exceptional example of marine pollution.[4]
Formation
Like other areas of concentrated marine debris in the world's oceans, the Eastern Garbage Patch has formed gradually over time as a result of marine pollution gathered by the action of oceanic currents.
The garbage patch occupies a large and relatively stationary region of the North Pacific Ocean bound by the North Pacific Gyre (a remote area commonly referred to as the horse latitudes). The rotational pattern created by the North Pacific Gyre draws in waste material from across the North Pacific Ocean, including the coastal waters off North America and Japan. As material is captured in the currents, wind-driven surface currents gradually move floating debris toward the center, trapping it in the region.
The size of the affected region is unknown, as large items readily visible from the deck of a boat are few and far between. Most of the debris consists of small plastic particles suspended at or just below the water surface, making it impossible to detect by aircraft or satellite images.[5] Estimates on size range from 700,000 km² to more than 15 million km², (0.41% to 8.1% of the size of the Pacific Ocean). The area may contain over 100 million tons of debris.[6] It has also been suggested that the patch may represent two areas of debris that are linked.[7]
Sources of pollutants
It has been estimated that 80% of the garbage comes from land-based sources, and 20% from ships at sea. Currents carry debris from the west coast of North America to the gyre in about five years, and debris from the east coast of Asia in a year or less.[8][9] An international project led by Dr. Hideshige Takada of Tokyo University studying plastic pellets from beaches around the world may provide further clues about the origins of pelagic plastic, including that of the Pacific garbage patch.[10]
Plastic photodegradation in the ocean
Main article: Photodegradation
The Eastern Garbage Patch has one of the highest levels of plastic particulate suspended in the upper water column. As a result, it is one of several oceanic regions where researchers have studied the effects and impact of plastic photodegradation in the neustonic layer of water.[11] Unlike debris which biodegrades, the photodegraded plastic disintegrates into ever smaller pieces while remaining a polymer. This process continues down to the molecular level.
As the plastic flotsam photodegrades into smaller and smaller pieces, it concentrates in the upper water column. As it disintegrates, the plastic ultimately becomes small enough to be ingested by aquatic organisms which reside near the ocean's surface. Plastic waste thus enters the food chain through its intense concentration in the neuston.
Density of neustonic plastics
Despite Charles Moore's description, the eastern garbage patch cannot be characterised as a continuous visible field of densely floating marine debris. The process of disintegration means that the plastic particulate in much of the affected region may be too small to be seen. Researchers must estimate the overall extent and density of plastic pollution in the EGP by taking samples. In a 2001 study, researchers (including Moore) found that in certain areas of the patch, concentrations of plastic reached one million particles per square mile.[12] The study found concentrations of plastics at 3.34 pieces with a mean mass of 5.1 milligrams per square meter. In many areas of the affected region, the overall concentration of plastics was greater than the concentration of zooplankton by a factor of seven. Samples collected at deeper points in the water column found much lower levels of plastic debris (primarily monofilament fishing line), confirming earlier observations that most plastic waste concentrates in the upper parts of the water column.
Impact on wildlife
The floating plastic particles resemble zooplankton, which can be inadvertently consumed by jellyfish. Many of these long-lasting plastics end up in the stomachs of marine birds and animals,[13] including sea turtles, and the Black-footed Albatross.[14] Besides the particles' danger to wildlife, the floating debris can absorb organic pollutants from seawater, including PCBs, DDT, and PAHs.[15] Aside from toxic effects,[16] when ingested, some of these are mistaken by the endocrine system as estradiol, causing hormone disruption in the affected animal.[14]
Cleanup
In 2008, Richard Owen, a building contractor and scuba dive instructor, formed the Environmental Cleanup Coalition to address the issue of the pollution of the North Pacific. The ECC plan calls for modifying a fleet of ships to clear the area of debris and form a restoration and recycling laboratory called Gyre Island.[1][17]
On 1 August 2009 it was announced that Doug Woodring (an ocean conservationist) working in conjunction with the Scripps Institution of Oceanography, would be embarking upon an expedition to the plastic vortex in order to explore, photograph, video and to alert the public to the growing threat of ocean waste. The first ship of the expedition departed California on 2 August with about 30 researchers, technicians and crew members. The 170-foot vessel New Horizon is equipped with a laboratory for on-board research, but scientists also will bring back samples for further study.
The second ship departed on 4 August. In addition to the potential harm to sea life caused by ingesting bits of plastic, the expedition team will look at whether the particles could carry other pollutants, such as pesticides, far out to sea, and whether tiny organisms attached to the debris could be transported to distant regions and thus become invasive species. Aside from conducting scientific research on the impact of the plastic vortex on marine life, the expedition will also experiment with ways to clean up the vortex without harming the marine life in and around it.[18][19]
