The Ocean Cleanup

The Ocean Cleanup is a nonprofit environmental engineering organization based in the Netherlands that develops and deploys technology to extract plastic pollution from the oceans and to capture it in rivers before it can reach the ocean. Their initial focus was on the Pacific Ocean and its garbage patch, and extended to rivers in countries including Indonesia, Guatemala, and the United States.
The Ocean Cleanup was founded in 2013 by Boyan Slat, a Dutch inventor who serves as its CEO. It develops both ocean and river based catch systems. Its ocean system consists of a funnel shaped floating barrier which is towed by two ships. The ocean system is deployed in oceanic gyres to collect marine debris. The project aims to launch 10 or more approximately 2 km-long (1.2 mi) systems which they predict could remove 50% of the debris in the Great Pacific Garbage Patch five years from deployment.
The river system consists of a variety of floating barriers and extraction systems which are anchored within rivers or at rivermouths. The Ocean Cleanup also publishes scientific papers, and estimates that "1% of worlds rivers (~1000 rivers) are responsible for 80% of the pollution in the world's seas". They aim to deploy their river systems in these 1000 rivers.
As of February 2025, the organization has removed over 21 million kilograms of trash from rivers and the Great Pacific Garbage Patch.
Slat proposed the cleanup project and supporting system in 2012. In October, he outlined the project in a TED-talk. The initial design consisted of long, floating barriers fixed to the seabed, attached to a central platform shaped like a manta ray for stability. The barriers would direct the floating plastic to the central platform, which would remove the plastic from the water. Slat did not specify the dimensions of this system in the talk.
In 2014, the design replaced the central platform with a tower detached from the floating barriers. This platform would collect the plastic using a conveyor belt. The floating barrier was proposed to be 100 km (62 mi) long. They conducted and published a feasibility study.
In 2015, this design won the London Design Museum Design of the Year, and the INDEX: Award. Later that year, scale model tests were conducted in wave pools at Deltares and MARIN, testing the dynamics and load of the barrier in ocean conditions, and gathering data for computational modeling.
A 100-metre (330 ft) segment went through a test in the North Sea in the summer of 2016. The test indicated that conventional oil containment booms would not stand up over time, and they changed the floater material to a hard-walled HDPE pipe.
In May 2017, significant changes to the conceptual design were made:
Tests in 2018 led to sea anchors being removed, and the opening of the U turned to face the direction of travel, by creating more drag in the middle with a deeper underwater screen.
On 9 September 2018, System 001 (nicknamed Wilson in reference to the floating volleyball in the 2000 film Cast Away) deployed from San Francisco. The ship Maersk Launcher towed the system to a position 240 nautical miles off the coast, where it was put through a series of sea trials. It consisted of a 600 m (2,000 ft) long barrier with a 3 m (9.8 ft) wide skirt hanging beneath it. It was made from HDPE, and consists of 50x12 m sections joined. It was unmanned and incorporated solar-powered monitoring and navigation systems, including GPS, cameras, lanterns and AIS. The barrier and the screen were produced by an Austrian supplier.
In October 2018 it was towed to the Great Pacific Garbage Patch for real-world duty. System 001 encountered difficulties retaining the plastic collected. The system collected debris, but soon lost it because the barrier did not retain a consistent speed through the water. In December, mechanical stress caused an 18-meter section to detach, and the rig was moved to Hawaii for inspection and repair. During the two months of operation, it had captured 2 metric tons of plastic.
In June 2019, after four months of root cause analyses and redesign, System 001/B was deployed, with a water-borne parachute to slow the system, and an extended cork line to hold the screen in place. This successfully captured smaller plastic, reduced the barrier size by two-thirds, and was easier to adjust offshore. However, System 001/B still did not adequately capture and retain debris.
In October 2019, The Ocean Cleanup unveiled a barrier for river cleanup, The Interceptor, to intercept river plastic and prevent it from reaching the ocean. Two systems were deployed in Jakarta (Indonesia) and Klang (Malaysia).
In January 2020, flooding broke the barrier of Interceptor 001 in Jakarta. It was replaced with a newer model with a stronger screen, simpler design, and an adjustable better-defined weak link. A third Interceptor was deployed in Santo Domingo, in the Dominican Republic. In December, The Ocean Cleanup announced they would start large-scale production of the Interceptor series.
In July 2022, an Interceptor Original was deployed near the mouth of Ballona Creek in southwestern Los Angeles County, California. This was the first Interceptor Original installed in the United States, and the second of its kind to be deployed globally.
In May 2022, the Ocean Cleanup trialed a new Interceptor called Trashfence on the Rio Las Vacas, a tributaty of the Rio Motagua, in Guatemala. It was anchored to the riverbed, and the anchors washed out. In April 2023, they returned with a pair of new Interceptors, at a point on the river with slower current, anchored to the riverbank. This was successful, and soon became their most prolific site; in its first year it removed 10,000,000 kg of trash from the river.
In July 2021, a new design called System 002, also known as "Jenny", was deployed in the Great Pacific Garbage Patch for testing. System 002 was actively towed by two ships as opposed to System 001 which passively drifted. In October, the organization announced that the system had gathered 28,000 kilograms (62,000 lb) of trash. In October, the project announced plans for System 03, which would span up to 2.5 km (1.6 mi).
By December, the project announced it had removed more than 150 tonnes of plastic from the Great Pacific Garbage Patch and announced it would transition to the new longer System 03 the following year.
In May 2023, the project deployed its System 03 barrier, 2,250 meters long. The system included a retention zone where material is held before it is removed from the water, with the nets' mesh size there being increased from 10 to 15 mm. This is to allow marine life such as fish and turtles to escape, and to allow smaller creatures such as blue buttons and violet snails to pass through.
System 03 has about 5x the capacity of System 002, which is why they dropped a 0 from the naming scheme:
In June 2024, the project claimed that it had removed 15 million kilograms (33 million lb) of marine trash from the Great Pacific Garbage Patch and from key polluting rivers around the world since 2019.
The latest 03 design uses a towed floating structure. The structure acts as a containment boom. A permeable screen underneath the float catches subsurface debris and funnels it into the Retention Zone which serves as a debris catch. The Retention Zone is monitored by underwater cameras. If an animal is spotted in the Retention Zone, the Marine Animal Safety Hatch (MASH) is activated, blocking off any further entrance into the Retention Zone while opening an exit hatch and giving the animal a clear route out.
Crewed boats tow the approximately 2.2km U-shaped barrier through the water at 1.5 knots. The ship is steered to areas with higher waste densities. In July 2022, the floating system reached the milestone of 100,000 kg of plastic removed from the Great Pacific Garbage Patch.
The Interceptor is a solar-powered, automated system designed to capture and extract waste. Along with an optimized water flow path, a barrier guides rubbish towards the opening of the Interceptor and onto the conveyor belt, which delivers waste to the shuttle. The shuttle deposits the waste equally into one of six bins according to sensors. When the bins are almost full, local operators are informed with an automated message. They then empty them and send the waste to local waste management facilities. The Interceptor project is similar to a smaller-scale local project called Mr. Trash Wheel developed in 2008 for Maryland's Baltimore harbor.
In 2021, The Ocean Cleanup began expanding their Interceptor systems to be able to tackle a wider range of rivers. The Interceptor Barricade developed for Rio Las Vacas in 2023 was the first model designed for very high-throughput rivers that may carry 10,000 kg of trash a day.
In August 2015, The Ocean Cleanup conducted the Mega Expedition, in which a fleet of approximately 30 vessels, with lead ship R/V Ocean Starr, crossed the Great Pacific Garbage Patch and mapped an area of 3.5 million square kilometers. The expedition collected data on the size, concentration and total mass of the plastic in the patch. According to the organization, this expedition collected more data on oceanic plastic pollution than the last 40 years combined.
In September and October 2016, The Ocean Cleanup launched the Aerial Expedition, in which a C-130 Hercules aircraft conducted the first ever series of aerial surveys to map the Great Pacific Garbage Patch. The goal was specifically to quantify the amount of large debris, including ghost nets in the patch. Slat stated that the crew saw more debris than expected.
The project released an app called The Ocean Cleanup Survey App, which enables others to survey the ocean for plastic, and report their observations.
In February 2015, the research team published a study in Biogeosciences about the vertical distribution of plastic, based on samples collected in the North Atlantic Gyre. They found that plastic concentration decreases exponentially with depth, with the highest concentration at the surface, and approaching zero just a few meters deeper. A follow-up paper was published in Scientific Reports in October 2016.
In June 2017, researchers published a paper in Nature Communications, with a model of the river plastic input into the ocean. Their model estimates that between 1.15 and 2.41 million metric tons of plastic enter the world's oceans every year, with 86% of the input stemming from rivers in Asia. In December 2017, they published a paper in Environmental Science & Technology about pollutants in oceanic plastic they had sampled.
In March 2018, they published a paper in Scientific Reports, summarizing the combined findings from the two expeditions. They estimated that the Patch contains 1.8 trillion pieces of floating plastic, with a total mass of 79,000 metric tons. Microplastics (< 0.5 cm) make up 94% of the pieces, accounting for 8% of the mass. The study suggests that the amount of plastic in the patch increased exponentially since 1970.
In September 2019, they published a paper in Scientific Reports studying why emissions into the ocean are higher than the estimates of debris accumulated at the surface layer of the ocean. They argue that debris circulation dynamics offer an explanation for this missing plastic and suggest that there is a significant amount of time between initial emissions and accumulation offshore. The study also indicated that current microplastics are mostly a result of the degradations of plastic produced in the 1990s or before. A follow-up study in May 2020 showed that part of the plastic at the surface of the Great Pacific Garbage Patch is breaking down into microplastics and sinking to the deep sea. Most debris is still found at the surface, with 90% in the first 5 meters.
In October 2019, other researchers estimated that most ocean plastic pollution comes from cargo ships, with a majority from Chinese cargo ships alone. A spokesperson from The Ocean Cleanup said: "Everyone talks about saving the oceans by stopping using plastic bags, straws and single use packaging. That's important, but when we head out on the ocean, that's not necessarily what we find."
The Ocean Cleanup raised over US$2 million with the help of a crowdfunding campaign in 2014.
As of 2019, it was mainly funded by donations and in-kind sponsors, including Maersk, Salesforce.com chief executive Marc Benioff, Peter Thiel, Julius Baer Foundation, The Coca-Cola Company and Royal DSM.
In 2019, it received a 10 million AUD award from the Macquarie Group Foundation as part of its 50th anniversary celebration.
In October 2020, they unveiled a product made from plastic certified from the Great Pacific Garbage Patch, The Ocean Cleanup sunglasses, to help fund the continuation of the cleanup. They made 21,000 sunglasses, sold at €200 apiece. They worked with DNV GL to develop a certification for plastic from water sources and the sunglasses were certified to originate from the GPGP. The sunglasses were designed by Yves Béhar and manufactured by Safilo. They sold out in early 2022.
In October 2021, they were part of the #TeamSeas fundraising campaign led by YouTube stars Mark Rober and MrBeast, and received roughly half of the $30 million raised.
In 2022, Kia signed a seven-year deal to become a global partner of The Ocean Cleanup through funding and in-kind contributions. The partnership will fund the construction of a new Interceptor and will allow for recycled plastics to be used in the manufacturing process of Kia.
In early 2023 the organization received its largest private donation to date of $25 million from Joe Gebbia, co-founder of Airbnb.
Criticisms and doubts about method, feasibility, efficiency and return on investment have been raised in the scientific community. Miriam Goldstein, director of ocean policy at the Center for American Progress, stated in 2019 that compared to the ocean system, devices closer to shore are easier to maintain, and would likely recover more plastic per dollar spent overall.
The team has expressed their own concerns that the devices could imperil sea life, including neustons, communities of pleustons, Portuguese man-of-war, sea snails, and sail jellyfish that live near the ocean surface, and have monitored for such impacts. A modelling study concluded that it is currently impossible to determine how damaging at-sea plastic removal strategies (such as those of The Ocean Cleanup) would be for marine life, with impacts potentially ranging from mild to severe.
It is understood that this approach cannot solve the whole problem. Plastic in the oceans is spread far beyond the gyres; experts estimate that less than 5% of all the plastic pollution which enters the oceans makes its way into any of the garbage patches. Much of the plastic that does make it to gyres is not floating at the surface, though recent research confirms it is mostly within the first meters. Plastic in rivers can be more easily trapped at the source but that accounts for only a part of all plastic in the oceans.
In 2022, the organization collected 923,000 kg of ocean and river plastic with the expenses of €45.603 million; a cost of €49.4/kg.
In 2023 the efficacy has significantly improved due to the upscaling of the river systems. A total of 8531 metric tons of ocean and river plastic was collected with the expense of €44.507 million; a cost of €5.22/kg.
The project and its founder have been recognized in many fora.