Great Pacific garbage patch

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vessels from Project Kaisei, the New Horizon and the Kaisei, embarked on a voyage to research the patch and determine the feasibility of commercial scale collection and recycling. 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. It occupies a relatively stationary region of the North Pacific |last2=Lebreton|first2=Laurent C. M.|last3=Carson|first3=Henry S.|last4=Thiel|first4=Martin|last5=Moore|first5=Charles J.|last6=Borerro|first6=Jose C.|last7=Galgani|first7=G.|last9=Reisser|first9=Julia|date=10 December 2014|others=|title=Plastic Pollution in the World's Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea|url=http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111913%7Cjournal=PLOS One|volume=9|issue=12|pages=e111913|doi=10.1371/journal.pone.0111913|issn=1932-6203|pmc=4262196|pmid=25494041|bibcode=2014PLoSO...9k1913E}}</ref> of the mass of plastic marine debris. According to a 2011 [[United States Environmental

| first=David | date=May–June 2009 of Asia in a year or less.

A 2017 study 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 remains in the oceans and land.

Size estimates

Visualisation showing how mass accumulates in gyres.

The size of the patch is indefinite, as is the precise distribution of debris, because large items are uncommon. Most debris consists of small plastic particles suspended at or just below the surface, evading detection 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 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.

— Ryan et al

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 found that, although the patch contains 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 that are visible just beneath the surface suggests the affected area may be much smaller. 2009 data collected from Pacific albatross populations suggest the presence of two distinct debris zones.

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 overflew the patch in 2016 with a C-130 Hercules aircraft, equipped with LiDAR sensors. The findings from the two expeditions, found that the patch covers 1.6 million square kilometers with a concentration of 10–100 kg per square kilometer. They estimate an 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.

NOAA stated:

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.

— Ocean Facts, National Ocean Service

Photodegradation of plastics

See also: Photodegradation and Microplastics

Washed-up plastic waste on a beach in Singapore

The patch 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, plastic disintegrates into ever smaller pieces while remaining a polymer (without changing chemically). This process continues down to the molecular level. Some plastics decompose within a year of entering the water, releasing 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 pieces become small enough to be ingested by aquatic organisms that reside near the ocean's surface. Plastic may become concentrated in neuston, thereby entering the food chain.

Disintegration means that much of the plastic is too small to be seen. In a 2001 study, researchers 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. 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

NOAA's marine debris removal in 2014

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. 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 then 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.

Affected species include sea turtles and the black-footed albatross. Midway Atoll receives substantial amounts of marine debris from the patch.

Direct harm to species

Of the 1.5 million Laysan albatrosses that inhabit Midway Atoll, nearly all are likely to have plastic in their gastrointestinal tract. Approximately one-third of their chicks die, and many of those deaths are from plastic unwittingly fed to them by their parents. Twenty tons of plastic debris washes up on Midway every year with five tons ending up in the bellies of albatross chicks. Fish and whales may also mistake the plastic as a food source.

Indirect harm via the food chain

On the microscopic level, debris can absorb organic pollutants from seawater, including PCBs, DDT and PAHs. Aside from toxic effects, some of these are mistaken by the endocrine system as estradiol, disrupting hormone levels in affected animals. These toxin-containing plastic pieces are also eaten by jellyfish, which are then eaten by fish and then by humans.

Spreading invasive species

Marine plastics facilitate the spread of invasive species that attach to floating plastic in one region and drift long distances to colonize other ecosystems. Debris affects at least 267 species worldwide.

Increasing microplastic concentrations has released the insect Halobates sericeus from substrate limitation. A positive correlation between H. sericeus and microplastic was observed, along with increasing H. sericeus egg densities.

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

Further reading

• Oliver J. Dameron; Michael Parke; Mark A. Albins; 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. doi:10.1016/j.marpolbul.2006.11.019. PMID 17217968.
• Rei Yamashita; Atsushi Tanimura (2007). "Floating plastic in the Kuroshio Current area, western North Pacific Ocean". Marine Pollution Bulletin. 54 (4): 485–488. doi:10.1016/j.marpolbul.2006.11.012. PMID 17275038.
• Masahisa Kubota; Katsumi Takayama; Noriyuki Horii (2000). "Movement and accumulation of floating marine debris simulated by surface currents derived from satellite data" (PDF). School of Marine Science and Technology, Tokai University.
• Gregory, M.R.; Ryan, P.G. (1997). "Pelagic plastics and other seaborne persistent synthetic debris: a review of Southern Hemisphere perspectives". In Coe, J.M.; Rogers, D.B. (eds.). Marine Debris: Sources, Impacts, Solutions. New York: Springer-Verlag. pp. 49–66.
• Moore, Charles G.; Phillips, Cassandra (2011). Plastic Ocean. Penguin Group. ISBN 9781452601465. {{cite book}}: Invalid |ref=harv (help)
• Density of plastic particles found in zooplankton trawls from coastal waters of California to the North Pacific Central Gyre – Charles J Moore, Gwen L Lattin and Ann F Zellers (2005)
• H. Day, Robert; Shaw, David; E. Ignell, Steven (1 January 1990). "The quantitative distribution and characteristics of neuston plastic in the North Pacific Ocean, 19841988" (PDF). {{cite journal}}: Cite journal requires |journal= (help)
• Morton, Thomas (2007). "Oh, This is Great, Humans Have Finally Ruined the Ocean". Vice magazine. pp. 78–81. Archived from the original on 4 July 2008. {{cite web}}: |archive-date= / |archive-url= timestamp mismatch; 25 July 2008 suggested (help)
• Hohn, Donovan (2011). Moby-Duck: The True Story of 28,800 Bath Toys Lost at Sea. Viking. ISBN 978-0-670-02219-9.
• Hoshaw, Lindsey (9 November 2009). "Afloat in the Ocean, Expanding Islands of Trash". The New York Times. Retrieved 10 November 2009.
• Newman, Patricia (1 April 2014). Plastic, Ahoy!: Investigating the Great Pacific Garbage Patch. Millbrook Press. ISBN 9781467725415.

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.
• The Ocean Cleanup. "Scientific publications". Retrieved 21 October 2018.