On 2 October 2019, The Ocean Cleanup announced that its floating barrier, System 001/B, was finally catching and holding plastic in the Great Pacific Garbage Patch. After a year of setbacks, the redesigned system was retaining everything from obvious debris and large abandoned fishing nets to microplastic fragments as small as one millimetre. It was a modest catch, but it was the first proof that the basic idea could work in the open ocean.
This article explains what System 001/B was, the engineering fix that made the difference, what the trial did and did not prove, and how the project grew afterwards.
The problem System 001/B had to solve
The Ocean Cleanup was founded in 2013 by Boyan Slat, a Dutch inventor born in Delft in July 1994, which made him 25 at the time of the 2019 announcement. He first pitched the idea of letting ocean currents carry plastic into a long floating barrier at a TEDxDelft talk in 2012, and the video went viral.
Turning the concept into hardware proved hard. The first full system, System 001 (nicknamed “Wilson”), left San Francisco in September 2018. It was meant to drift with the plastic but slightly faster, so debris would pile up against it. In practice it did not keep a steady speed difference, so plastic drifted in and then floated back out. In December 2018 mechanical stress caused an 18-metre section to break off, and the barrier was towed to Hawaii for repairs. Critics, who had questioned the design for years, felt vindicated.
The Ocean Cleanup
The photo above, credited to The Ocean Cleanup, shows the barrier at sea: a long floating pipe that keeps a screen hanging below the surface, curving into a U shape so that debris is guided towards the centre.
The fix: slowing the barrier down
For the second attempt, engineers flipped the approach. Instead of trying to make the barrier move faster than the plastic, they made it move slower. A large parachute-style sea anchor was attached to drag in the water, so wind and waves pushed the plastic into the barrier rather than the barrier chasing the plastic. That gave a more consistent speed difference, which is what the system needed to catch anything at all.
A second problem then appeared: some plastic was washing over the top. While the system was still offshore, the crew enlarged the cork line along the float, and the team reported that overtopping became minimal. System 001/B left Vancouver in June 2019 and spent the summer and early autumn in the patch.
The barrier carried solar-powered lights, cameras, sensors and satellite antennae, so the team could track its position and watch its behaviour remotely. A support vessel periodically collected the catch and brought it to shore.
Up close, a retained catch looks less like an island of rubbish and more like a scattered mix of crates, buoys, bottle fragments, rope and net. That variety was exactly what the team wanted to see: proof that the barrier could hold both large and small pieces.
What the 2019 trial showed
In its announcement, the organisation said the first year of testing “strongly indicates that our vision is attainable.” Three things stood out:
- The system held plastic of very different sizes, from microplastics around 1 mm to large ghost nets.
- The sea-anchor approach created the steady speed difference that the first version lacked.
- Repairs and adjustments could be made at sea, which suggested the design could be improved without starting from scratch.
The team was also open about the limits. System 001/B was small and still lost some of its catch, and it could not hold plastic for long periods. The stated next step was to design System 002, a full-scale system able to retain plastic for longer and return it to land for recycling.
In case you missed it, here is a short recap of our announcement today. pic.twitter.com/bGhrkty5W6
— The Ocean Cleanup (@TheOceanCleanup) October 2, 2019
Our vessel (with cleanup system) now in transit to port for crew change; expect to be back in the patch for final leg of the System 001/B campaign around Oct 17. pic.twitter.com/P9rmxU136w
— Boyan Slat (@BoyanSlat) October 3, 2019
The photos and posts above document the campaign. The first two images show the barrier and its retention area in the patch. The Ocean Cleanup’s own tweet from 2 October 2019 recapped the announcement, and a day later Boyan Slat posted that the vessel and system were heading to port for a crew change before a final leg of the campaign later that month.
Wildlife: what we know and what we do not
Any structure placed in the ocean raises questions about marine life. During the 2019 campaign, the organisation reported that monitoring had not observed adverse effects on wildlife, and that animals could swim beneath the screen. That is a useful early observation, but it is not proof of zero impact under every condition.
Scientists have pointed in particular to neuston, the community of small animals that live at the sea surface, such as Portuguese man-of-war and floating sea snails, which could be gathered along with plastic. The Ocean Cleanup itself has acknowledged that risk. Its later barriers added more monitoring, and System 03 includes an escape hatch that can be opened if animals are seen in the retention zone.
The bigger picture of ocean plastic
Nearly 8 million metric tons of plastic enter the ocean every year. pic.twitter.com/p2iYjP1bId
— Vala Afshar (@ValaAfshar) October 2, 2019
The tweet above repeats a widely shared figure of about 8 million tonnes a year. It comes from a 2015 study in Science that estimated between 4.8 and 12.7 million tonnes of plastic entered the ocean from coastal countries in 2010. The midpoint is often rounded to 8 million, so it is best read as an estimate with a wide range rather than an exact count.
Plastic harms wildlife in two main ways. Animals become entangled in nets, rope and packaging, and many species, from fish to seabirds and turtles, swallow fragments that can block their gut or leave them feeling full without nourishment. Lost fishing gear keeps trapping animals for years, which is why it is called ghost fishing. Plastics can also carry additives and absorb other pollutants, although how much of that moves up the food chain is still being studied.
Most ocean plastic overall is thought to come from land, washed down rivers or blown from coasts. The Great Pacific Garbage Patch is different: a 2018 study found that fishing nets made up close to half of its plastic mass. That is one reason why an open-ocean barrier and land-based prevention are complementary rather than rival solutions.
You may also have read that by 2050 the oceans could hold more plastic than fish by weight. That claim comes from a 2016 projection presented at the World Economic Forum in Davos. It rests on assumptions about plastic production and fish stocks, and researchers have questioned how reliable it is, so it is better treated as a warning than as a forecast.
What happened after System 001/B
The 2019 test led to System 002, a much larger barrier that was towed by two ships rather than drifting. In its 2021 trial it removed about 28,659 kg of plastic in nine runs. It was followed in 2023 by System 03, a barrier about 2.25 to 2.5 km long. The organisation has also expanded into rivers with solar-powered “Interceptors” that catch waste before it reaches the sea.
By July 2026, The Ocean Cleanup reported more than 60 million kilograms of trash removed from rivers and the patch combined. Those totals mix river waste of every kind with ocean plastic, so they are not directly comparable with the small 2019 catch. The organisation also stresses that the patch still holds far more plastic than has been removed.
The video above shows the floating barrier at sea during the 2019 campaign.
Why the 2019 milestone still matters
System 001/B was small, imperfect and short-lived, yet it changed the conversation. It showed that the mechanism could work once the speed problem was understood, and it gave the team the data to design something bigger. It also showed the value of admitting failure publicly and iterating at sea.
For readers, the takeaway is practical: clean-up and prevention both count. Reducing single-use plastic, recycling correctly and supporting river and beach clean-ups all stop waste before it ever reaches a place as remote as the North Pacific gyre.
Sources: The Ocean Cleanup: System 001/B announcement, 2 October 2019; The Ocean Cleanup: System 002 milestone page; Wikipedia: The Ocean Cleanup; Wikipedia: Boyan Slat; Wikipedia: Great Pacific garbage patch; Wikipedia: Marine plastic pollution. Photos: The Ocean Cleanup.
COMMENTS