Floating Garbage Patches in the Oceans
The Great Pacific Garbage Patch is the area of the North Pacific where ocean currents concentrate plastic waste.
The Great Pacific Garbage Patch is the area of the North Pacific, roughly between Hawaii and California, where ocean currents concentrate plastic waste. There is no island to walk on, and most of the plastic is spread through the top few metres of water.[5] The most widely used measurement, published in 2018, put the area at 1.6 million square kilometres, the mass at about 80,000 tonnes and the count at 1.8 trillion pieces. About 46% of the mass was fishing net.[2][3] Sometimes called a seventh continent in the press, the patch is the product of half a century of accumulation.
The First Records of Plastic at Sea
Plastic in the open ocean entered the scientific record in 1972. Edward Carpenter and K. L. Smith of the Woods Hole Oceanographic Institution reported floating fragments in the western Sargasso Sea in the journal Science, at an average of 3,500 pieces and 290 grams per square kilometre.[1] Rules on ships came later. MARPOL Annex V entered into force on 31 December 1988, and amendments effective on 1 January 2013 made it a general ban on discharging garbage at sea.[10]
Where the plastic would collect is a matter of currents. The Pacific, Atlantic and Indian oceans hold five large gyres. Wind and the Earth's rotation turn the water in a ring, and whatever floats drifts slowly towards its calm centre. A NOAA paper of 1988, drawing on measurements of surface plastic by researchers in Alaska, predicted that such an accumulation would form in the North Pacific gyre.[2]
The Ever Laurel's Toys
Four years later an accident made those currents easier to follow. On 10 January 1992 the Evergreen container ship Ever Laurel, on her way from Hong Kong to Tacoma, ran into a storm near the International Date Line and lost twelve containers. One of them held 28,800 plastic bath toys: yellow ducks, green frogs, blue turtles and red beavers.[4]
On 16 November 1992 a beachcomber near Sitka, Alaska, found ten of them. Two Seattle oceanographers, Curtis Ebbesmeyer and James Ingraham, began gathering reports. Ingraham's OSCUR model used air pressure data from 1967 onward to work out surface currents, and the toys gave it a ready test. About 400 had turned up along the eastern Gulf of Alaska by August 1993, and landfalls in Washington State in 1996 were correctly predicted.[4] The work showed what path a floating object follows in the North Pacific.
Charles Moore's 1997 Route
The person who made the patch known was a sailor. Captain Charles Moore of Long Beach had founded Algalita in 1994 to study and restore kelp forests off Southern California.[8] Returning from the Transpacific Yacht Race in 1997, he took his boat Alguita through the North Pacific gyre and found the water scattered with plastic fragments.[8][9] Ebbesmeyer named the area the Eastern Garbage Patch.[2]
Moore went back to measure what he had seen, starting about 20 years of research voyages in 1999. Algalita's study that year reported plastic outweighing zooplankton in the area by about six to one. A similar measurement off the California coast in 2002 gave five to two.[8][9] News reports spread these findings with words like garbage island and seventh continent, and NOAA had to correct them. According to the agency there is no continuous, visible mass. Wind and waves mix small pieces through the upper water, and someone sailing through may see little or nothing on the surface.[5]
Midway's Albatrosses
The pictures in those years came from Midway Atoll, north-west of Hawaii, more than from the patch itself. Laysan albatrosses skim food from the surface and regurgitate it for their chicks, and plastic takes the same route to the nest. The US Fish and Wildlife Service estimates that adult birds carry more than five tons of it to the atoll each year. Once a body decays, the lighters and caps from its stomach stay on the sand.[11] An NPR report of 2007 said the US government reckoned 50 tons of plastic reached Midway's waters each year.[11]
Measuring the Patch
For a long time nobody knew the patch's real size. Boyan Slat, a young Dutchman, saw more plastic than fish while diving in Greece in 2011. He described a current-driven collection idea at a TEDx talk in Delft in 2012 and founded The Ocean Cleanup in 2013.[12] Collecting required measuring first. In 2015 the organisation had 30 vessels tow 652 surface nets, gathering 1.2 million pieces, and in 2016 a C-130 Hercules surveyed 311 square kilometres on two flights with lidar, infrared and cameras.[3]
Laurent Lebreton and colleagues published the results in Scientific Reports on 22 March 2018. The area lay roughly between 135 and 155 degrees west and 35 and 42 degrees north and was about twice the size of Texas. Concentrations reached hundreds of kilograms per square kilometre at the centre and fell to about 10 at the edge. The mass was put at 45,000 to 129,000 tonnes, with 80,000 as the central figure, although the organisation's current page says 100,000, so the sources differ here. Microplastics were 94% of the pieces but only 8% of the mass.[2][3]
The Fishing Share
The composition surprised people most. Fishing nets were about 46% of the mass, which fits poorly with the familiar picture of bags and bottles. On 1 September 2022 Lebreton's team published a study of 6,093 items larger than 5 centimetres, tracing rigid debris to five industrialised fishing nations. On that basis the organisation attributes 75% to 86% of the plastic in the patch to offshore fishing.[2][3]
That ties the problem directly to work at sea. Ghost nets come from people working on the water, and they keep catching animals after they are lost. The garbage rules for ships can be checked through the record book during port state control, but finding the owner of a net lost at sea is much harder.
Clean-Up Attempts
Attempts to take plastic out of the patch began in 2009 with Project Kaisei. The New Horizon and the Kaisei went to see whether commercial-scale collection could work and brought back about 4.5 tonnes using prototype equipment.[2] The figure showed the difficulty, since scattered fragments mean searching a very wide area.
The Ocean Cleanup towed its first system out of San Francisco on 9 September 2018 to a trial site about 240 nautical miles offshore. System 001, designed to drift passively with the current, ran into technical problems during its four-month trial and returned to port in 2019. A revised version caught its first plastic that year.[2][12] The next design changed approach. System 002, towed by two ships, went out in 2021, and by the time it came back for the last time on 21 August 2023 it had cleaned 8,352 square kilometres and removed 282,787 kilograms of plastic. The larger System 03 replaced it.[12] Ocean Voyages Institute meanwhile took 150 tonnes out on two sailing expeditions in 2020, including 93 tonnes on a first voyage of 45 days.[2]
The Ocean Cleanup says it removed more than 25 million kilograms of trash in 2025, taking its total past 45 million. These figures include river interceptors and coastal sweeps and are not the patch alone. Its stated goal is to remove 90% of floating ocean plastic by 2040.[6] The work has moved to rivers for that reason, since new plastic keeps arriving from land to replace what comes out. Time matters as well. Plastic at sea breaks up under sunlight and waves without really decomposing, and below 5 millimetres it cannot be netted, so today's large piece becomes tomorrow's microplastic.[3]
The Plastics Treaty
UN talks on a global treaty that would slow the flow from land began in 2022. The Geneva session of August 2025 ended without agreement, and the chair, Luis Vayas Valdivieso, stepped down. A one-day session in Geneva on 7 February 2026 did no more than elect a new chair, Julio Cordano of Chile. The divide between countries seeking limits on production and those wanting to focus on waste remains. Reports from March 2026 expected formal talks in late 2026 or early 2027, with date and venue unconfirmed.[7] Ship-sourced plastic stays a separate matter for IMO.
Frequently asked questions
What is the Great Pacific Garbage Patch?
The Great Pacific Garbage Patch is the area of the North Pacific where ocean currents concentrate plastic waste.
Is the Great Pacific Garbage Patch really an island?
According to NOAA there is no continuous mass. Most of the plastic is in small pieces spread through the upper water, and a passing ship may see little on the surface.
How big is the Great Pacific Garbage Patch?
The 2018 measurement found about 80,000 tonnes of plastic over about 1.6 million square kilometres. The edges shift with the currents, so the figure is an estimate.
Sources
- Carpenter E. J., Smith K. L. Plastics on the Sargasso Sea Surface, Science, vol. 175, March 1972.
- Wikipedia. Great Pacific Garbage Patch.
- The Ocean Cleanup. The Great Pacific Garbage Patch (summary of Lebreton et al., Scientific Reports, 2018 and 2022).
- Wikipedia. Friendly Floatees Spill.
- NOAA National Ocean Service. What Is the Great Pacific Garbage Patch.
- The Ocean Cleanup. 2025 in Review.
- Seven Seas Media. Global Plastics Treaty, New Chair Julio Cordano, March 2026; Recycling Today. New Chair Elected at Third Part of Fifth Session.
- Moore Institute for Plastic Pollution Research. Our History.
- Wikipedia. Charles J. Moore.
- IMO. Prevention of Pollution by Garbage from Ships (MARPOL Annex V).
- US Fish and Wildlife Service. The Trash at the Edge of the World; NPR. Remote Waters Offer No Refuge from Plastic Trash, 2007.
- The Ocean Cleanup. What Jenny Taught Us: Lessons from System 002; Wikipedia. Boyan Slat; Wikipedia. The Ocean Cleanup.
