Indian Ocean Garbage Patch
Encyclopedia
The Indian Ocean Garbage Patch, discovered in 2010, is a gyre of marine litter suspended in the upper water column of the central Indian Ocean
, specifically the Indian Ocean Gyre
, one of the five major oceanic gyre
s. The patch does not appear as a continuous debris field. As with other patches in each of the five oceanic gyres, the plastics in it break down to ever smaller particles, and to constituent polymers. As with the other patches, the field constitutes an elevated level of pelagic plastic
s, chemical sludge, and other debris
; primarily particles that are generally invisible to the naked eye.
A similar patch of floating plastic debris in the Pacific Ocean, the Great Pacific Garbage Patch
, was predicted in 1985, and discovered in 1997 by Charles J. Moore
as he passed through the North Pacific Gyre on his return from the Transpacific Yacht Race
. The North Atlantic Garbage Patch
was discovered in 2010.
(NOAA) of the United States
. The prediction was based on results obtained by several Alaska-based researchers between 1985 and 1988 that measured neuston
ic plastic in the North Pacific Ocean. It was extrapolated from the findings of high concentrations of marine debris, that similar conditions would occur in other parts of the Pacific where prevailing currents were favorable to the creation of relatively stable waters, and this was also verified.
Recent data collected from Pacific albatross
populations suggest there may be two distinct zones of concentrated debris in the Pacific.
Research studying trash washed onto beaches in and around the Indian Ocean suggested that there would be plastics found in the water column in the Indian Ocean as well.
In 2010, the Five Gyres Project set off on the first of its planned series of transoceanic voyages to determine whether the South Atlantic, South Pacific, and Indian Ocean gyres were affected in the same way as the North Pacific and North Atlantic gyres. On the Indian Ocean leg of their trip, they travelled between Perth, Australia
, and Port Louis, Mauritius (east of Madagascar); each of the water samples they collected in the 3,000 miles between contained plastic.
have studied the patches. Unlike debris, which biodegrades
, the photodegraded plastic disintegrates into ever smaller pieces while remaining a polymer
. This process continues down to the molecular level
. Large items readily visible from a boat deck do exist, but are uncommon; most debris consists of small plastic particles 'confetti
-like' pieces are clearly visible suspended at or just below the surface, as confirmed by the August 2009 Scripps Institution of Oceanography
/ Project Kaisei
SEAPLEX survey mission of the North Pacific Gyre. Despite its size and density
, the patch is not visible from space with conventional satellite photography, since the majority of particles are too small.
The patches form gradually as a result of marine pollution gathered by oceanic currents
. The gyres' rotational pattern draws in waste material from surrounding waters; the currents prevent the escape of the material but do not prevent the relatively weaker force of wind-driven surface currents gradually moving floating debris toward the center.
Floating debris typically is sampled with a neuston
or manta trawl
net lined with 0.33 mm mesh. Long-term changes in plastic meso-litter have been reported using surface net tows: in the North Pacific Subtropical Gyre in 1999, plastic abundance was 335 000 items km2 and 5.1 kg km2, roughly an order of magnitude greater than samples collected in the 1980s. Similar dramatic increases in plastic debris have been reported off Japan.
In a 2001 study of the Pacific gyre, in many of the sampled areas, the overall concentration of plastics was seven times greater than the concentration of zooplankton
. Samples collected at deeper points in the water column found much lower concentrations of plastic particles (primarily monofilament fishing line pieces). The mass of the Great Pacific Garbage Patch is estimated at 100 million tons.
An international research project led by Dr. Hideshige Takada of Tokyo University studying plastic pellets, or nurdles, from beaches around the world may provide further clues about the origins of pelagic plastic.
through its concentration in the neuston
. Some plastics decompose within a year of entering the water, leaching potentially toxic chemicals such as bisphenol A
, PCBs
and derivatives of polystyrene
.
The food chain
in the gyres and surrounding ocean areas are affected, beginning with small fish and jellyfish
, and ending in larger fish, birds and humans. Marine plastics also facilitate the spread of invasive species that attach to floating plastic in one region and drift long distances to colonize other ecosystems.
Some of the long-lasting plastics end up in the stomachs of marine birds and animals, and their young, including sea turtle
s and the Black-footed Albatross
. Besides the particles' danger to wildlife, the floating debris can absorb organic pollutants from seawater, including PCBs
, DDT
, and PAHs
. Aside from toxic effects, when ingested, some of these are mistaken by the endocrine system as estradiol
, causing hormone disruption in the affected animal.
Research has shown that this plastic marine debris affects at least 267 species worldwide and a few of the 267 species reside in the North Pacific Gyre.
In April 2008 the Environmental Cleanup Coalition was formed to identify methods to safely remove plastic and persistent organic pollutant
s from the oceans. The Algalita Marine Research Foundation built a raft made of plastic junk
and sailed it across the Pacific in 2008 to report on the issue; Project Kaisei
, a project to study and clean up the garbage patch was launched in March 2009.
The SEAPLEX expedition, a group of researchers from Scripps Institution of Oceanography
, spent 19 days on the ocean in August, 2009 researching the N. Pacific patch. Their primary goal was to describe the abundance and distribution of plastic in the gyre in the most rigorous study to date. Researchers were also looking at the impact of plastic on mesopelagic fish, such as lanternfish
.
In 2010, the Five Gyres Project found that the South Atlantic, South Pacific, and Indian Ocean gyres were affected in the same way as the North Pacific and North Atlantic gyres. Anna Cummins, cofounder of 5 Gyres Institute called the pollution they found "a thin plastic soup".
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
, specifically the Indian Ocean Gyre
Indian Ocean Gyre
The Indian Ocean Gyre, located in the Indian Ocean, is one of the five major oceanic gyres.- External links:*...
, one of the five major oceanic gyre
Gyre
A gyre in oceanography is any large system of rotating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Coriolis Effect; planetary vorticity along with horizontal and vertical friction, which determine the circulation patterns from the wind curl...
s. The patch does not appear as a continuous debris field. As with other patches in each of the five oceanic gyres, the plastics in it break down to ever smaller particles, and to constituent polymers. As with the other patches, the field constitutes an elevated level of pelagic plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
s, chemical sludge, and other debris
Debris
Debris is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, in geology, large rock fragments left by a melting glacier etc. The singular form of debris is debris...
; primarily particles that are generally invisible to the naked eye.
Great Pacific Garbage Patch
The Great Pacific Garbage Patch, also described as the Pacific Trash Vortex, is a gyre of marine litter in the central North Pacific Ocean located roughly between 135°W to 155°W and 35°N to 42°N...
, was predicted in 1985, and discovered in 1997 by Charles J. Moore
Charles J. Moore
Charles J. Moore is an oceanographer and racing boat captain known for articles that recently brought attention to the 'Great Pacific Garbage Patch', an area of the Pacific Ocean strewn with floating plastic debris which is twice the size of Texas....
as he passed through the North Pacific Gyre on his return from the Transpacific Yacht Race
Transpacific Yacht Race
The Transpacific Yacht Race is an offshore yacht race starting off Point Fermin, San Pedro, near Los Angeles, and ending off Diamond Head Lighthouse in Honolulu, a distance of around . Started in 1906, it is one of yachting's premier offshore races and attracts entrants from all over the world...
. The North Atlantic Garbage Patch
North Atlantic Garbage Patch
The North Atlantic Garbage Patch is an area of marine debris found floating within the North Atlantic Gyre, originally documented in 1972. The patch is estimated to be hundreds of kilometers across in size, with a density of over 200,000 pieces of debris per square kilometer...
was discovered in 2010.
Discovery
The existence of the Great Pacific Garbage Patch, the first to be discovered, was predicted in a 1988 paper published by the National Oceanic and Atmospheric AdministrationNational Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...
(NOAA) of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The prediction was based on results obtained by several Alaska-based researchers between 1985 and 1988 that measured neuston
Neuston
right|250px|thumb|Two [[water strider]]s, common neustonsNeuston is the collective term for the organisms that float on the top of water or live right under the surface . Neustons are made up of some species of fish , beetles , protozoans, bacteria and spiders...
ic plastic in the North Pacific Ocean. It was extrapolated from the findings of high concentrations of marine debris, that similar conditions would occur in other parts of the Pacific where prevailing currents were favorable to the creation of relatively stable waters, and this was also verified.
Recent data collected from Pacific albatross
Albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes . They range widely in the Southern Ocean and the North Pacific...
populations suggest there may be two distinct zones of concentrated debris in the Pacific.
Research studying trash washed onto beaches in and around the Indian Ocean suggested that there would be plastics found in the water column in the Indian Ocean as well.
In 2010, the Five Gyres Project set off on the first of its planned series of transoceanic voyages to determine whether the South Atlantic, South Pacific, and Indian Ocean gyres were affected in the same way as the North Pacific and North Atlantic gyres. On the Indian Ocean leg of their trip, they travelled between Perth, Australia
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
, and Port Louis, Mauritius (east of Madagascar); each of the water samples they collected in the 3,000 miles between contained plastic.
Formation
Researchers into the effects and impact of plastic photodegradationPhotodegradation
Photodegradation is degradation of a photodegradable molecule caused by the absorption of photons, particularly those wavelengths found in sunlight, such as infrared radiation, visible light, and ultraviolet light. However, other forms of electromagnetic radiation can cause photodegradation...
have studied the patches. Unlike debris, which biodegrades
Biodegradation
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...
, the photodegraded plastic disintegrates into ever smaller pieces while remaining a polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
. This process continues down to the molecular level
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
. Large items readily visible from a boat deck do exist, but are uncommon; most debris consists of small plastic particles 'confetti
Confetti
Confetti is a multitude of pieces of paper, mylar or metallic material which is usually thrown at parades and celebrations, especially weddings . Confetti is made in a variety of colors, and commercially available confetti is available in imaginative shapes...
-like' pieces are clearly visible suspended at or just below the surface, as confirmed by the August 2009 Scripps Institution of Oceanography
Scripps Institution of Oceanography
Scripps Institution of Oceanography in La Jolla, California, is one of the oldest and largest centers for ocean and earth science research, graduate training, and public service in the world...
/ Project Kaisei
Project Kaisei
Project Kaisei is a scientific and commercial mission to study and clean up the Great Pacific Garbage Patch, a large body of floating debris trapped in the Pacific Ocean by the currents of the North Pacific Gyre. Discovered by NOAA, the patch is estimated to contain 20 times the density of...
SEAPLEX survey mission of the North Pacific Gyre. Despite its size and density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
, the patch is not visible from space with conventional satellite photography, since the majority of particles are too small.
The patches form gradually as a result of marine pollution gathered by oceanic currents
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
. The gyres' rotational pattern draws in waste material from surrounding waters; the currents prevent the escape of the material but do not prevent the relatively weaker force of wind-driven surface currents gradually moving floating debris toward the center.
Floating debris typically is sampled with a neuston
Neuston
right|250px|thumb|Two [[water strider]]s, common neustonsNeuston is the collective term for the organisms that float on the top of water or live right under the surface . Neustons are made up of some species of fish , beetles , protozoans, bacteria and spiders...
or manta trawl
Manta trawl
A Manta Trawl is a net system for sampling the surface of the ocean. It resembles a manta ray, with metal wings and a broad mouth. The net it pulls is made of thin mesh, and the whole trawl is towed behind a scientific research vessel...
net lined with 0.33 mm mesh. Long-term changes in plastic meso-litter have been reported using surface net tows: in the North Pacific Subtropical Gyre in 1999, plastic abundance was 335 000 items km2 and 5.1 kg km2, roughly an order of magnitude greater than samples collected in the 1980s. Similar dramatic increases in plastic debris have been reported off Japan.
In a 2001 study of the Pacific gyre, in many of the sampled areas, the overall concentration of plastics was seven times greater than the concentration of zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
. Samples collected at deeper points in the water column found much lower concentrations of plastic particles (primarily monofilament fishing line pieces). The mass of the Great Pacific Garbage Patch is estimated at 100 million tons.
Sources of pollutants
Ship-generated pollution is a source of concern since a typical 3,000 passenger cruise ship produces over eight tons of solid waste weekly. Pollutants range in size from abandoned fishing nets to micro-pellets used in abrasive cleaners. Moore estimated that 80% of the garbage comes from land-based sources and 20% from ships.An international research project led by Dr. Hideshige Takada of Tokyo University studying plastic pellets, or nurdles, from beaches around the world may provide further clues about the origins of pelagic plastic.
Ecological studies and conservation efforts
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 chainFood chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
through its concentration in the neuston
Neuston
right|250px|thumb|Two [[water strider]]s, common neustonsNeuston is the collective term for the organisms that float on the top of water or live right under the surface . Neustons are made up of some species of fish , beetles , protozoans, bacteria and spiders...
. Some plastics decompose within a year of entering the water, leaching potentially toxic chemicals such as bisphenol A
Bisphenol A
Bisphenol A is an organic compound with two phenol functional groups. It is used to make polycarbonate plastic and epoxy resins, along with other applications....
, PCBs
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
and derivatives of polystyrene
Polystyrene
Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...
.
The food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
in the gyres and surrounding ocean areas are affected, beginning with small fish and jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
, and ending in larger fish, birds and humans. Marine plastics also facilitate the spread of invasive species that attach to floating plastic in one region and drift long distances to colonize other ecosystems.
Some of the long-lasting plastics end up in the stomachs of marine birds and animals, and their young, including sea turtle
Sea turtle
Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...
s and the Black-footed Albatross
Black-footed Albatross
The Black-footed Albatross, Phoebastria nigripes, is a large seabird from the North Pacific of the albatross family Diomedeidae. It is one of three species of albatross that range in the northern hemisphere, nesting on isolated tropical islands...
. Besides the particles' danger to wildlife, the floating debris can absorb organic pollutants from seawater, including PCBs
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
, DDT
DDT
DDT is one of the most well-known synthetic insecticides. It is a chemical with a long, unique, and controversial history....
, and PAHs
Polycyclic aromatic hydrocarbon
Polycyclic aromatic hydrocarbons , also known as poly-aromatic hydrocarbons or polynuclear aromatic hydrocarbons, are potent atmospheric pollutants that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. Naphthalene is the simplest example of a PAH...
. Aside from toxic effects, when ingested, some of these are mistaken by the endocrine system as estradiol
Estradiol
Estradiol is a sex hormone. Estradiol is abbreviated E2 as it has 2 hydroxyl groups in its molecular structure. Estrone has 1 and estriol has 3 . Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect...
, causing hormone disruption in the affected animal.
Research has shown that this plastic marine debris affects at least 267 species worldwide and a few of the 267 species reside in the North Pacific Gyre.
In April 2008 the Environmental Cleanup Coalition was formed to identify methods to safely remove plastic and persistent organic pollutant
Persistent organic pollutant
thumb|right|275px|State parties to the Stockholm Convention on Persistent Organic PollutantsPersistent organic pollutants are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes...
s from the oceans. The Algalita Marine Research Foundation built a raft made of plastic junk
Junk raft
A junk raft is a type of home-built watercraft made of plastic bottles or other recycled materials constructed by and for three different sorts of audiences: artists and community-minded groups organizing recreational flotillas; environmentally concerned individuals seeking to draw attention to the...
and sailed it across the Pacific in 2008 to report on the issue; Project Kaisei
Project Kaisei
Project Kaisei is a scientific and commercial mission to study and clean up the Great Pacific Garbage Patch, a large body of floating debris trapped in the Pacific Ocean by the currents of the North Pacific Gyre. Discovered by NOAA, the patch is estimated to contain 20 times the density of...
, a project to study and clean up the garbage patch was launched in March 2009.
The SEAPLEX expedition, a group of researchers from Scripps Institution of Oceanography
Scripps Institution of Oceanography
Scripps Institution of Oceanography in La Jolla, California, is one of the oldest and largest centers for ocean and earth science research, graduate training, and public service in the world...
, spent 19 days on the ocean in August, 2009 researching the N. Pacific patch. Their primary goal was to describe the abundance and distribution of plastic in the gyre in the most rigorous study to date. Researchers were also looking at the impact of plastic on mesopelagic fish, such as lanternfish
Lanternfish
Cooper Lanternfishes are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represented by 246 species in 33 genera, and are found in oceans worldwide. They are aptly named after their conspicuous use of bioluminescence...
.
In 2010, the Five Gyres Project found that the South Atlantic, South Pacific, and Indian Ocean gyres were affected in the same way as the North Pacific and North Atlantic gyres. Anna Cummins, cofounder of 5 Gyres Institute called the pollution they found "a thin plastic soup".
External links
- greatgarbagepatch.org
- Pacific Garbage Patch - Smithsonian Ocean Portal
- "Plastic Surf" The Unhealthful Afterlife of Toys and Packaging: Small remnants of toys, bottles and packaging persist in the ocean, harming marine life and possibly even us by Jennifer Ackerman Scientific AmericanScientific AmericanScientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...
August 2010 - photographer Chris Jordan, who recently traveled to a remote part of the Pacific Ocean to document effects of the world’s largest known mass of garbage. in Seed (magazine)Seed (magazine)Seed is an online science magazine published by Seed Media Group. The magazine looks at big ideas in science, important issues at the intersection of science and society, and the people driving global science culture...
- Scripps Environmental Accumulation of Plastic Expedition (SEAPLEX) — Scripps Institution of Oceanography, UC San Diego
- The Project Kaisei Voyage Tracker — Project Kaisei and Ojingolabs
- 5 Gyres - Understanding Plastic Marine Pollution — Algalita, Livable Legacy
- The trash vortex — Greenpeace
- Navigating the Pacific's 'Garbage Patch' — National Public Radio and me
- Marine Research, Education and Restoration — Algalita Marine Research Foundation
- Images & video from the North Pacific gyre — WordPress.com
- Sea of Trash - New York Times Magazine
- Captain Charles Moore on the seas of plastic
- Charles Moore: Sailing the Great Pacific Garbage Patch - TED Conference talk (2009)