IT WAS a glorious sunny day in September 2023. Excitement filled the air and a rainbow stretched across the horizon as the team slowly hauled a giant net out of the glistening sea. project was in the North Pacific, trialling its System 03 – essentially two ships dragging a 2.2-kilometre-long net designed to remove as much trash as possible. On this occasion, filmed for a promotional video, it managed a record-breaking 18 tonnes in a single scoop.
The Ocean Cleanup was founded in 2012 on a simple premise: trawl ocean plastic hotspots and sweep up the floating refuse. Now, after years of testing and improving its technology, the organisation says it is ready to start systematically removing the Great Pacific Garbage Patch, a vast collection of plastic waste between Hawaii and California.
That sounds like a laudable goal. But in recent years, marine scientists have been warning that efforts to mechanically take plastics out of our seas are not only futile, but also potentially harmful. Futile, because we have learned that much of the plastic waste in the oceans is too small or too out of reach to be captured. And harmful, perhaps, for two reasons: because the latest research shows ocean garbage patches are home to all manner of marine life and because clean-up operations could distract from efforts to stem the flow of such waste at source.
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So, given what we know now about the extent of ocean plastics and the nature of these collections in the Pacific and elsewhere, the question has surfaced: is cleaning up these garbage patches a good idea, after all?
Oceanographers were aware that discarded plastic was accumulating in hotspots in the Pacific since the 1970s. But the problem only surfaced in the public consciousness thanks to the efforts of boat captain Charles Moore, who came face to face with the true extent of it in 1997 on his way back to the US mainland from a two-week yacht race in Hawaii.
What is the Great Pacific Garbage Patch?
Sailing through the North Pacific Subtropical Gyre, a vortex formed by ocean currents that most sailors avoid owing to a lack of wind, he found himself surrounded by plastic waste: everything from bleach bottles, volleyballs and truck tyres to parts of a TV. “As I gazed from the deck at the surface of what ought to have been a pristine ocean, I was confronted, as far as the eye could see, with the sight of plastic,” .
He went on to work with oceanographers to chart the extent of the problem and, crucially, raise awareness. As they slowly mapped and studied 1.6 million square kilometres of sea between Hawaii and California, they began to refer to it as the “Eastern Pacific Garbage Patch”. Strictly speaking, that eastern patch forms part of a wider system that also includes a western patch off the coast of Japan and a “convergence zone” that acts as a highway moving debris between the two. But these days, when most scientists refer to the Great Pacific Garbage Patch, they are referring to the eastern section. There are similar trash-collecting gyres in the Atlantic and Indian Oceans. However, the Great Pacific Garbage Patch, which is twice the size of Texas, is the biggest and by far the most infamous. Despite this, or maybe because of it, the patch has been shrouded in misconceptions – and we are still learning about it today.
Back in 2018, the estimated amount of plastic it contained was , four to 16 times as much as previous estimates. The source of the plastic was long thought to be household refuse. But analysis of over 6000 pieces of debris collected from the patch by The Ocean Cleanup in 2022 found that . “Plastic that comes from land and rivers tends to stick around coastlines because of the tides, winds and currents. Just a small part makes it offshore,” says , head of environmental and social affairs at the project. Fishing, meanwhile, is often done far out at sea.
The Great Pacific Garbage Patch is often referred to as an artificial island, giving the impression of a more-or-less solid mass. However, big chunks of plastic floating in the patch are relatively few and far between. It is more of an oceanic soup made up of billions of tiny shards, known as microplastics, each measuring less than 5 millimetres across. Swimmer and conservation activist , who swam over 500 kilometres through the patch in 2019, says “it was like swimming in a snowstorm, you have this tiny plastic all around you”. Sure enough, of the estimated 1.8 trillion pieces of plastic the patch contains, some .
Many of the risks posed by these tiny fragments to marine life are well-documented. The bio-accumulation of microplastics has been linked to , and . But some problems are just coming to light. In 2021, , then at the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany, and her colleagues observed that , . In that sense, the researchers found, the presence of microplastics is undermining the ocean’s ability to sustain marine life.
A new plastic ecosystem
Yet perhaps the most interesting thing we are learning about the Great Pacific Garbage Patch is that the larger chunks of plastic, of which there are many despite the fact they make up only a small percentage of the total, are now providing a novel habitat for marine life.
In 2022, researchers including , then at the University of North Carolina, Asheville, studied samples gathered by Lecomte during one of his epic swims. They found that the patch is teeming with aquatic life – mostly tiny floating “neustons”, surface-dwelling aquatic organisms ranging from snails to jellyfish. “One of the tragedies of naming the North Pacific Gyre the garbage patch is that it erases the reality that it is, and always has been, an ecosystem,” says Helm, now at Georgetown University in Washington DC.
A year earlier, Linsey Haram at the Smithsonian Environmental Research Center in Maryland, and her colleagues, had found that 90 per cent of marine debris analysed was , ranging from tiny invertebrates known as bryozoans and barnacles to small marine insects and crabs. Then in 2023, a study led by Haram found that three-quarters of the species living on the plastic were coastal, rather than those of non-coastal, or pelagic, waters. This adds to a growing body of evidence that suggests plastic is , enabling coastal species to adapt to living out at sea. “The plastisphere may now provide extraordinary new opportunities for coastal species to expand populations into the open ocean and become a permanent part of the pelagic community,” wrote Haram and her colleagues, “fundamentally altering the oceanic communities and ecosystem processes in this environment.”
You could be forgiven for thinking that, on balance, clearing up this ocean plastic must be a good idea, and The Ocean Cleanup is certainly pushing ahead. Its system for doing so has changed over the years, but the fundamentals are simple. Shaped like a horseshoe protruding out from a central reservoir, two 2.2-kilometre-long “wings” push the plastic towards a floating barrier with a net dangling up to 4 metres below the surface. As it is pulled behind two boats, plastic collected by the net is slowly funnelled to the middle of the barrier, where it moves into a central “retention zone” – essentially, a giant trash bag.
So far, the process has collected several hundred tonnes of plastic in total. Its newly launched system is now ready for full-scale operations, capable of scooping up many tonnes of waste in one go, as the 2023 expedition demonstrated. Even within the patch, currents create areas of denser plastic waste, so the organisation is now using machine learning to pre-empt and track those, to make its efforts more efficient.
Are ocean cleanups a good idea?
But, as critics have pointed out, it isn’t as simple as just sweeping the problem away. For starters, collecting large bits of plastic isn’t going to deal with the tiny plastic particles that make up most of the waste in the Great Pacific Garbage Patch. While there have been some interesting studies into nature-based solutions to the microplastic problem – one from the Plymouth Marine Laboratory in the UK found those fragments from water – there is currently no viable way to get microplastics out of the ocean, let alone at the scale needed.
Even when it comes to the larger pieces of plastic in the patch, there are reasons to question the idea that we should seek to remove them. One of the main issues with the system is animals that are accidentally caught up in the net. “When The Ocean Cleanup posted some of their first pictures of their plastic capture, I went through and circled the hundreds of animals that were also caught in their net,” says Helm.
The current system tries to minimise this bycatch in various ways. By moving at half the pace of a walking human, with multiple openings, there are meant to be plenty of opportunities for animals to evade being caught or to escape. Disruptive lights and sounds are also designed to keep them away. Egger says that, as a result, only 0.3 per cent of the catch was marine life when using the most recent versions, but this was by weight, so large items of plastic could skew the results.
Despite its precautions, the system can’t stop all of the collateral damage. Neustons are almost impossible to separate from waste, for one. An environmental impact assessment by the group from 2021 suggested that, even at the slowest speeds, the previous system would pick up millions of these creatures a day.
The emerging picture of a neopelagic ecosystem might complicate matters, too. Egger, who was a co-author of the 2023 study led by Haram, describes these coastal species as “invasive” and argues that they could be “competing for the very limited resources for the species that are naturally occurring out there”. This is an argument for getting rid of them. But Helm says many of the coastal species have a long history of riding on more natural ocean flotsam. “If disturbances to the ecosystem by plastic is the real problem, is further disturbing the ecosystem to clean up plastic actually a solution?” he asks.
All of this aside, an overarching issue is whether these areas are worth spending so much effort on at all. The Great Pacific Garbage Patch is, after all, just the sharp end of a global plastics crisis. Each year, an estimated 11 million tonnes of plastic trash goes into the ocean each year. Only 1 per cent ends up in garbage patches. Scientists just aren’t sure where the other 99 per cent is. Thanks to currents, they think a lot of it stays within 160 kilometres of the shore, moving along coasts and up and down from the seafloor, slowly being broken down. A large share is also thought to be trapped in Arctic ice. Why target plastics caught in gyres, given they make up such a small amount of the ocean plastic?
It isn’t as if these garbage patches are easy to get to, either. “All of the gyres exist in the very centre, more or less, of the ocean basins,” says at the Ocean Conservancy organisation. “It’s very costly, time-intensive and fuel-intensive to actually get out there.” He cites research from Imperial College London, published in 2016, that shows .
Then there is the question of what happens to the waste once it has been collected. The hope is that it can be reused or recycled in some way. The Ocean Cleanup, for example, announced that would see recycled ocean plastic used in the car-maker’s new models. But the breakdown of plastic that has been in the ocean for a long time often makes that kind of outcome impossible, forcing it to be put into landfill, where it can still contaminate the soil and air.
In November 2023, a collaboration including at the University of Plymouth in the UK cautioned against physical clean-ups as the main way to tackle ocean plastic, calling them a fallacy. The resulting report cites a frightening figure: that . “The concern here is that there’s a distraction to something that’s really managing symptoms, rather than solving the root cause,” says Thompson.
The plastic waste problem
The Ocean Cleanup is in favour of changing the way we consume plastic (see “The plastic fight”, below). In recent years, it has put an increasing amount of work into building machines that intercept plastic flowing down waterways, with systems operating in multiple rivers. But “even if we stop emissions, there’s already a lot of plastic doing a lot of harm to the marine environment”, says Egger. He thinks the two solutions complement each other, since the company’s data on types of plastic and where it is coming from can help people who are working on prevention. “A clean-up can do much more than clean up,” he says.
Still, that doesn’t change the fact that , two-thirds of which becomes waste. “Cleaning up the open ocean is a Sisyphean feat,” says Mallos. “These things can come in parallel,” says Thompson. “But we need to be putting 1 per cent of our efforts into this kind of clearing and 99 per cent into turning off the tap.”
The plastic fight
In the two and a half decades since the Great Pacific Garbage Patch (see main story) was discovered, recycling rates have shot up and countries have begun banning or taxing some single-use plastic. While the amount of plastic produced each year hasn't started to fall yet, the UN is working on a new global treaty to control the production and disposal of the material, a move that conservationists hope could set limits on the volume of new plastics, or at least improve the process of disposal and recycling. "I think it's actually quite amazing how quickly we're moving," says Matthias Egger at The Ocean Cleanup, a project to tackle marine plastic patches.
It is impossible to say how much of this is thanks to public awareness of the garbage patch, but since its rise to infamy "the notion of a floating island of trash has done more good than harm", says Nick Mallos at the Ocean Conservancy. "That visibility, the almost overnight media sensation, elevated the broader societal issue of plastic pollution in a way I don't think any other media or marketing effort could have done."
Andrew Kersley is a freelance writer based in London
