The Great Pacific garbage patch, also described as the Pacific trash vortex, is a gyre of marine debris particles in the central North Pacific Ocean discovered between 1950 and 1988. It is located roughly between 135°W to 155°W and 35°N to 42°N. The collection of plastic, floating trash halfway between Hawaii and California extends over an indeterminate area of widely varying range depending on the degree of plastic concentration used to define the affected area.
The patch is characterized by exceptionally high relative pelagic concentrations of plastic, chemical sludge, and other debris that have been trapped by the currents of the North Pacific Gyre. Despite the common public image of islands of floating rubbish, its low density (4 particles per cubic meter) prevents detection by satellite imagery, or even by casual boaters or divers in the area. It consists primarily of an increase in suspended, often microscopic, particles in the upper water column.
Video Great Pacific garbage patch
Discovery
The Great Pacific garbage patch was described in a 1988 paper published by the National Oceanic and Atmospheric Administration (NOAA) of the United States. The description was based on results obtained by several Alaska-based researchers in 1988 that measured neustonic plastic in the North Pacific Ocean. Researchers found relatively high concentrations of marine debris accumulating in regions governed by ocean currents. Extrapolating from findings in the Sea of Japan, the researchers hypothesized that similar conditions would occur in other parts of the Pacific where prevailing currents were favorable to the creation of relatively stable waters. They specifically indicated the North Pacific Gyre.
Charles J. Moore, returning home through the North Pacific Gyre after competing in the Transpacific Yacht Race in 1997, claimed to have come upon an enormous stretch of floating debris. Moore alerted the oceanographer Curtis Ebbesmeyer, 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.
The Pacific garbage patch is not easily seen from the sky, because the plastic is dispersed over a large area. Researchers from The Ocean Cleanup have found the patch to cover an area of 1.6 million square kilometers. The plastic concentration is estimated to be up to 100 kilograms per square kilometer in the center of the patch, going down to 10 kilograms per square kilometer in the outer parts of the patch. There is an estimate of 80,000 metric tons of plastic in the patch, totaling 1.8 trillion pieces. When accounting for the total mass, 92% of the debris found in the patch consists of objects larger than 0.5 centimeters.
A similar patch of floating plastic debris is found in the Atlantic Ocean, called the North Atlantic garbage patch.
Maps Great Pacific garbage patch
Origin and constitution
It is thought that, like other areas of concentrated marine debris in the world's oceans, the Great Pacific garbage patch formed gradually as a result of ocean or marine pollution gathered by ocean 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 gyre's rotational pattern draws in waste material from across the North Pacific Ocean, including 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.
There is no strong scientific data concerning the origins of pelagic plastics. In a study published in 2014, researchers sampled 1571 locations throughout the worlds oceans, and determined that discarded fishing gear such as buoys, lines, and nets accounted for more than 60% of the mass of plastic marine debris. According to a 2011 EPA report, "The primary source of marine debris is the improper waste disposal or management of trash and manufacturing products, including plastics (e.g., littering, illegal dumping) ... Debris is generated on land at marinas, ports, rivers, harbors, docks, and storm drains. Debris is generated at sea from fishing vessels, stationary platforms, and cargo ships." Pollutants range in size from abandoned fishing nets to micro-pellets used in cosmetics and abrasive cleaners. Currents carry debris from the west coast of North America to the gyre in about six years, and debris from the east coast of Asia in a year or less.
A 2017 study conducted by scientists from the University of California, Santa Barbara, and the University of Georgia, concluded that of the 9.1 billion tons of plastic produced since 1950, close to 7 billion tons are no longer in use. The authors estimate that 9% was recycled, 12% was incinerated, and the remaining 5.5 billion tons litters the oceans and land.
Another recent Australian study focused on seafloor plastic pollution. The researchers from the Institute for Marine and Antarctic Studies at the University of Tasmania stated, "while the huge volume of plastic debris accumulating in the world's oceans and on beaches has received global attention, the amount of plastic accumulating on the seafloor is relatively unknown."
Estimates of size
The size of the patch is unknown, as is the precise distribution of debris, because large items readily visible from a boat deck are uncommon. Most debris consists of small plastic particles suspended at or just below the surface, making it difficult to accurately detect by aircraft or satellite. Instead, the size of the patch is determined by sampling. Estimates of size range from 700,000 square kilometres (270,000 sq mi) (about the size of Texas) to more than 15,000,000 square kilometres (5,800,000 sq mi) (about the size of Russia). Such estimates, however, are conjectural given the complexities of sampling and the need to assess findings against other areas. Further, although the size of the patch is determined by a higher-than-normal degree of concentration of pelagic debris, there is no standard for determining the boundary between "normal" and "elevated" levels of pollutants to provide a firm estimate of the affected area.
Net-based surveys are less subjective than direct observations but are limited regarding the area that can be sampled (net apertures 1-2 m and ships typically have to slow down to deploy nets, requiring dedicated ship's time). The plastic debris sampled is determined by net mesh size, with similar mesh sizes required to make meaningful comparisons among studies. Floating debris typically is sampled with a neuston or manta trawl net lined with 0.33 mm mesh. Given the very high level of spatial clumping in marine litter, large numbers of net tows are required to adequately characterize the average abundance of litter at sea. 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. However, caution is needed in interpreting such findings, because of the problems of extreme spatial heterogeneity, and the need to compare samples from equivalent water masses, which is to say that, if an examination of the same parcel of water a week apart is conducted, an order of magnitude change in plastic concentration could be observed.
In August 2009, the Scripps Institution of Oceanography/Project Kaisei SEAPLEX survey mission of the Gyre found that plastic debris was present in 100 consecutive samples taken at varying depths and net sizes along a path of 1,700 miles (2,700 km) through the patch. The survey also confirmed that, although the debris field does contain large pieces, it is on the whole made up of smaller items that increase in concentration toward the gyre's centre, and these 'confetti-like' pieces are clearly visible just beneath the surface. Although many media and advocacy reports have suggested that the patch extends over an area larger than the continental U.S., recent research sponsored by the National Science Foundation suggests the affected area may be much smaller. Recent data collected from Pacific albatross populations suggest there may be two distinct zones of concentrated debris in the Pacific.
In March 2018, The Ocean Cleanup published a paper summarizing their findings from the Mega- (2015) and Aerial Expedition (2016). In 2015, the organization crossed the Great Pacific garbage patch with 30 vessels, to make observations and take samples with 652 survey nets. They collected a total of 1.2 million pieces, which they counted and categorized into their respective size classes. In order to also account for the larger, but more rare larger debris, they also flew over the patch in 2016 with a C-130 Hercules aircraft, equipped with LiDAR sensors. The findings from the two expeditions, show that the patch is 1.6 million square kilometers and has a concentration of 10-100 kg per square kilometers. They estimate there to be 80,000 metric tons in the patch, with 1.8 trillion plastic pieces, out of which 92% of the mass is to be found in objects larger than 0.5 centimeters.
Photodegradation of plastics
The Great Pacific garbage patch has one of the highest levels known of plastic particulates 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. Unlike organic debris, which biodegrades, the photodegraded plastic disintegrates into ever smaller pieces while remaining a polymer. This process continues down to the molecular level. Some plastics decompose within a year of entering the water, leaching potentially toxic chemicals such as bisphenol A, PCBs, and derivatives of polystyrene. 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 that reside near the ocean's surface. In this way, plastic may become concentrated in neuston, thereby entering the food chain.
The process of disintegration means that the plastic particulate in much of the affected region is too small to be seen. In a 2001 study, researchers (including Charles Moore) found concentrations of plastic particles at 334,721 pieces per km2 with a mean mass of 5.1 kg (11.3 lbs) per km2, in the neuston. Assuming each particle of plastic averaged 5 mm × 5 mm × 1 mm, this would amount to 8 m2 per km2 due to small particulates. With respect to the overall ecology of the neuston, the overall concentration of plastics was seven times greater than the concentration of zooplankton in many of the sampled areas. Samples collected deeper in the water column found much lower concentrations of plastic particles (primarily monofilament fishing line pieces).
Effect on marine life and humans
The United Nations Ocean Conference estimated that the oceans might contain more weight in plastics than fish by the year 2050. Some long-lasting plastics end up in the stomachs of marine animals, mature and immature. The food chain is affected as the plastic attracts seabirds and fish. When marine life consumes plastic allowing it to enter the food chain, this can lead to greater problems when species that have consumed plastic are being eaten by other predators.
Animals can also become trapped in plastic nets and rings, which can cause death. Sea turtles are most affected by this.
Direct harm to species
Affected species include sea turtles and the black-footed albatross. Midway Atoll receives substantial amounts of marine debris from the patch. Of the 1.5 million Laysan albatrosses that inhabit Midway, nearly all are likely to have plastic in their digestive system. Approximately one-third of their chicks die, and many of those deaths are due to being fed plastic by their parents. Twenty tons of plastic debris washes up on Midway every year with five tons of that debris being fed to albatross chicks.
Indirect harm to species via the food chain
Besides the particles' danger to wildlife, on the microscopic level 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. These toxin-containing plastic pieces are also eaten by jellyfish, which are then eaten by fish. Many of these fish are then consumed by humans, resulting in their ingestion of toxic chemicals. While eating their normal sources of food, plastic ingestion can be unavoidable or the animal may mistake the plastic as a food source.
Spreading invasive species
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. Research has shown that this plastic marine debris affects at least 267 species worldwide.
Misconception
There has been some controversy surrounding the use of the term "garbage patch" and photos taken off the coast of Manila in the Philippines in attempts to portray the patch in the media often misrepresenting the true scope of the problem and what could be done to solve it. Angelicque White, Associate Professor at Oregon State University, who has studied the "garbage patch" in depth, warns that "the use of the phrase 'garbage patch' is misleading. ... It is not visible from space; there are no islands of trash; it is more akin to a diffuse soup of plastic floating in our oceans." In the article Dr. White and Professor Tamara Galloway, from the University of Exeter, call for regulation and cleanup and state that the focus should be on stemming the flow of plastic into the ocean from coastal sources.
The US National Oceanic and Atmospheric Administration (NOAA) agrees, saying:
While "Great Pacific Garbage Patch" is a term often used by the media, it does not paint an accurate picture of the marine debris problem in the North Pacific Ocean. The name "Pacific Garbage Patch" has led many to believe that this area is a large and continuous patch of easily visible marine debris items such as bottles and other litter--akin to a literal island of trash that should be visible with satellite or aerial photographs. This is not the case.
Cleanup research
In April 2008, Richard Sundance Owen, a building contractor and scuba dive instructor, formed the Environmental Cleanup Coalition (ECC) to address the issue of North Pacific pollution. ECC collaborates with other groups to identify methods to safely remove plastic and persistent organic pollutants from the oceans. The JUNK Raft Project was a trans-Pacific sailing voyage from June to August 2008 made to highlight the plastic in the patch, organized by the Algalita Marine Research Foundation.
Project Kaisei, a project to study and clean up the garbage patch, launched in March 2009. In August 2009, two project vessels, the New Horizon and the Kaisei, embarked on a voyage to research the patch and determine the feasibility of commercial scale collection and recycling. The SEAPLEX expedition, a group of researchers from Scripps Institution of Oceanography, spent 19 days on the ocean in August 2009 researching the 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. This group utilized a dedicated oceanographic research vessel, the 170 ft (52 m) long New Horizon.
In 2012, Miriam C. Goldstein, Marci Rosenberg, and Lanna Cheng wrote:
Plastic pollution in the form of small particles (diameter less than 5 mm)--termed "microplastic"--has been observed in many parts of the world ocean. They are known to interact with biota on the individual level, e.g. through ingestion, but their population-level impacts are largely unknown. One potential mechanism for microplastic-induced alteration of pelagic ecosystems is through the introduction of hard-substrate habitat to ecosystems where it is naturally rare. Here, we show that microplastic concentrations in the North Pacific Subtropical Gyre (NPSG) have increased by two orders of magnitude in the past four decades, and that this increase has released the pelagic insect Halobates sericeus from substrate limitation for oviposition. High concentrations of microplastic in the NPSG resulted in a positive correlation between H. sericeus and microplastic, and an overall increase in H. sericeus egg densities. Predation on H. sericeus eggs and recent hatchlings may facilitate the transfer of energy between pelagic- and substrate-associated assemblages. The dynamics of hard-substrate-associated organisms may be important to understanding the ecological impacts of oceanic microplastic pollution.
The Goldstein et al. study compared changes in small plastic abundance between 1972-1987 and 1999-2010 by using historical samples from the Scripps Pelagic Invertebrate Collection and data from SEAPLEX, a NOAA Ship Okeanos Explorer cruise in 2010, information from the Algalita Marine Research Foundation as well as various published papers.
At TEDxDelft2012, the Dutch aerospace engineering student Boyan Slat unveiled a concept for removing large amounts of marine debris from the five oceanic gyres. Calling his project The Ocean Cleanup, he proposed to use surface currents to let debris drift to specially designed arms and collection platforms. Operating costs would be relatively modest and the operation would be so efficient that it might even be profitable. The concept makes use of floating booms, that divert rather than catch the debris. This way bycatch would be avoided, although even the smallest particles would be extracted. According to Slat's calculations, a gyre could be cleaned up in five years' time, collecting at least 7.25 million tons of plastic across all gyres. He also advocated "radical plastic pollution prevention methods" to prevent gyres from reforming. In 2015, The Ocean Cleanup project was a category winner in the Design Museum's 2015 Designs of the Year awards. A fleet of 30 vessels, including a 32-metre (105-foot) mothership, took part in a month-long voyage to determine how much plastic is present using trawls and aerial surveys.
The 2012 Algalita/5 Gyres Asia Pacific Expedition began in the Marshall Islands on 1 May, investigated the little-studied Western Pacific garbage patch, collecting samples for the 5 Gyres Institute, Algalita Marine Research Foundation and several other colleagues, including NOAA, SCRIPPS, IPRC, and Woods Hole Oceanographic Institute. From 4 October to 9 November 2012, the Sea Education Association (SEA) conducted a research expedition to study plastic pollution in the North Pacific gyre. A similar research expedition was conducted by SEA in the North Atlantic Ocean in 2010. During the Plastics at SEA 2012 North Pacific Expedition, a total of 118 net tows were conducted and nearly 70,000 pieces of plastic were counted to estimate the density of plastics, map the distribution of plastics in the gyre, and examine the effects of plastic debris on marine life.
On 11 April 2013, artist Maria Cristina Finucci founded The Garbage Patch State at UNESCO--Paris in front of Director General Irina Bokova.
In 2016, plans were in the concept stage to create floating "oceanscrapers", made from the plastic found in the Great Pacific garbage patch. In early 2018, the Ocean Cleanup started the assembly of their first cleanup system, to be deployed in the Great Pacific garbage patch mid-2018.
Current research indicates that the Great Pacific Garbage Patch is rapidly accumulating plastic. A team surveyed buoyant ocean plastic with multiple vessels in July through September 2015 and aerial surveys in 2016. They wrote, "Our model, calibrated with data from multi-vessel and aircraft surveys, predicted at least 79 (45-129) thousand tonnes of ocean plastic are floating inside an area of 1.6 million km2; a figure four to sixteen times higher than previously reported."
See also
- Ecosystem of the North Pacific Subtropical Gyre
- Indian Ocean garbage patch
- Marine debris
- North Atlantic garbage patch
- Plastic pollution
- Plastic resin pellet pollution
- Plastisphere
- South Pacific garbage patch
References
Further reading
External links
- 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 American August 2010
- Plastic Paradise Movie - independent documentary by Angela Sun uncovering the mystery of the Great Pacific Garbage Patch known as the Plastic Paradise
- The source of the garbage patches, pictures
- Irish Examiner article
- Mega Expedition Departs Honolulu on YouTube
- Midway, a plastic island on YouTube
- Climate change, meet your apocalyptic twin: oceans poisoned by plastic. Public Radio International. 13 December 2016
- By 2050, the oceans could have more plastic than fish. Business Insider. 27 January 2017.
Source of article : Wikipedia
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