In October 2021, The Ocean Cleanup announced that its towed barrier, System 002, had pulled 28,659 kilograms (63,182 lb) of plastic out of the Great Pacific Garbage Patch during a trial that ran from July to October. That haul came from nine test extractions, and the biggest single one weighed 9,014 kg. It was the first time the Dutch non-profit could show that a full-scale system worked in the open ocean, and it set the stage for the larger System 03 that followed.
The number grabbed headlines, but the organisation itself framed the trial as a test of technology rather than a clean-up of the patch. Here is what System 002 actually did, how it worked, what it found, and how the project has moved on since.
What System 002 removed in 2021
System 002, nicknamed “Jenny”, was deployed in the eastern North Pacific in July 2021. Over roughly twelve weeks the crew tested it in nine runs, hauling the catch on deck each time and recording what came out. The organisation’s press release of 20 October 2021, issued from Victoria, British Columbia, gave the trial total and stated that the system had met three proof-of-technology goals: limited negative environmental impact, no safety incidents, and a meaningful amount of plastic extracted.
The debris ranged from small fragments to large “ghost nets”, the abandoned fishing gear that drifts for years. The team also listed everyday objects: toilet seats, toothbrushes, laundry baskets, shoes, crates and even sleds. In a video tweeted a few days later, founder Boyan Slat walked viewers through some of the oddest finds.
The beginning of the end of the Great Pacific Garbage Patch. pic.twitter.com/JNWIbpYJHa
— The Ocean Cleanup (@TheOceanCleanup) October 21, 2021
Boyan Slat, born in Delft in 1994, presented his first concept at a TEDxDelft talk in 2012 and founded The Ocean Cleanup in 2013. In the press release he was blunt about why the trial mattered, saying that “these kilograms are the most important ones we will ever collect, because they are proof that cleanup is possible.”
How the system works
System 002 is a long, U-shaped floating barrier with a net-like screen hanging beneath it. Two support vessels tow it slowly through the water. Because the barrier moves a little faster than the floating plastic, debris is funnelled into a “retention zone” at the back of the U. When that zone is full, the crew lifts it aboard, empties it and sends the system back to work.
That active towing was the big lesson of earlier attempts. The first barrier, System 001, launched from San Francisco in 2018, drifted passively with the wind and waves. It struggled to hold onto plastic, and in December 2018 an 18-metre section broke off. A modified version, System 001/B, added a parachute-like sea anchor in 2019 and did catch plastic, but it was still too small and too unreliable to scale. Towing the barrier solved the speed problem and let the crew steer it towards denser concentrations, using computer models that predict where plastic gathers.
Towing also lets people watch what is happening in real time, which matters for wildlife. The organisation says it monitors interactions with marine animals during operations. Its later System 03 added a marine-animal escape hatch that can be opened if creatures are spotted in the retention zone.
Why the Great Pacific Garbage Patch is so hard to clean
The patch is not a floating island you could walk on. It is a vast region between Hawaii and California, roughly between 135°W and 155°W and 35°N and 42°N, where currents in the North Pacific Subtropical Gyre concentrate debris. The Ocean Cleanup has estimated it covers about 1.6 million square kilometres, often described as twice the size of Texas, although any boundary is fuzzy because the figures rely on sampling.
A 2018 study led by Laurent Lebreton estimated about 79,000 tonnes of plastic in roughly 1.8 trillion pieces. Most of those pieces are microplastics, but most of the weight sits in larger items, and synthetic fishing nets made up nearly half the mass. That is useful context: a barrier that targets bigger objects, especially nets, removes plastic before it breaks down into fragments that are almost impossible to collect.
Boyan gives a 'trash tour' of the strangest objects we recovered from the Great Pacific Garbage Patch. pic.twitter.com/8VdslbCsmg
— The Ocean Cleanup (@TheOceanCleanup) October 26, 2021
The tweet above, from the day after the announcement, called the trial the beginning of the end of the patch. That is an aspiration, not a measurement. Even 28.7 tonnes is a small fraction of an estimated 79,000.
From System 002 to System 03
System 002 kept working after the trial. In the 2021 release, the organisation said the next step would be System 03, about three times larger at 2.5 km (1.5 miles) long, with a long-term plan for a fleet of ten such systems that could remove half of the patch’s plastic every five years.
The handover to System 03 began in July 2022. According to The Ocean Cleanup’s milestone page, System 002 went on to remove a total of 282,787 kg of trash across 8,352 square kilometres of ocean, with a record single trip of 31,816 kg in August 2023. System 03 entered service in 2023, and the organisation has since reported far larger combined totals that include its river “Interceptors”. Those river figures cover all kinds of waste, not only ocean plastic, so they should be read separately from the patch numbers.
Money remained the limiting factor. Shortly after the trial, Slat was widely quoted, including by Upworthy, as saying the team could move faster with more resources: “It’s really just a question of money.”
What happens to the plastic afterwards
The catch is brought ashore, sorted and tracked. The organisation says its harvested plastic is verified under a chain-of-custody scheme by the certification body DNV, so that products made from it can credibly claim to come from the patch. In 2020 it sold 21,000 pairs of sunglasses made from System 001/B plastic, with proceeds going back into the clean-up.
Recycling helps fund the work and gives the material a second life, but it is not a guarantee that the plastic will never become waste again. Any recycled object still needs to be used, collected and disposed of responsibly at the end of its life.
Common myths and fair criticism
Myth: the patch can be seen from space. It cannot. Most of the plastic is scattered and much of it is small, so from a ship the water often looks fairly clear until you sample it.
Myth: plastic simply disappears over time. Conventional plastics do not biodegrade in any meaningful timeframe at sea. Sunlight and waves break them into smaller pieces, which spread further and are eaten by fish, seabirds and other animals. Floating nets and lines also keep entangling wildlife, a problem known as ghost fishing.
Criticism: clean-up versus prevention. Some scientists question whether open-ocean clean-up is the best use of money. Marine scientist Miriam Goldstein, among others, has argued that collecting waste near shores and rivers is cheaper and recovers more plastic per dollar. Researchers have also pointed out that only a small share of ocean plastic ends up in the garbage patches, and that surface-dwelling creatures known as neuston could be harmed by large barriers. The Ocean Cleanup has responded partly by building river Interceptors and by publishing its own environmental assessments.
The fairest reading is that System 002 proved a concept. It showed that a towed barrier can gather and land meaningful amounts of plastic from the middle of the Pacific. Whether a fleet can finish the job depends on funding, engineering, wildlife safeguards, and, above all, on cutting the flow of new plastic into the sea.
What readers can do
The simplest contribution is upstream: use fewer single-use plastics, put waste in the right bin, and support local beach and river clean-ups, which stop debris before it reaches the gyres. If you donate to a clean-up group, look for one that publishes verified totals and explains what happens to the waste it collects.
Sources: The Ocean Cleanup press release, 20 October 2021; The Ocean Cleanup: System 002 milestone page; originally reported by Upworthy; Wikipedia: The Ocean Cleanup; Wikipedia: Great Pacific garbage patch; Wikipedia: Boyan Slat. Embedded videos: The Ocean Cleanup on X (Twitter).
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