The 22-year-old trying to clean up the Great Pacific Garbage Patch

Boyan Slat was 16 when he came up with a way to rid the world’s oceans of plastic. He has recounted his epiphany so many times that he can no longer tell the tale without a degree of self-reflexivity. “You probably know the story, I’ve said it 1,000 times,” the 22-year-old told me recently. “I was diving in Greece and there were more plastic bags than fish.” Slat, who was born and brought up in the small city of Delft in the Netherlands, returned home from his holiday and began researching the problem in earnest.

The plastic bags he’d seen while diving were just a tiny part of a global predicament. Plastic entered the mass market in the early 20th ­century, and as the material found its way into almost every aspect of people’s lives across the developed world, few thought about where all the plastic they were using would end up. It was not until the 1970s that governments and producers began to invest in recycling. Even today the proportion of plastic that is recycled remains low; of the 78 million tonnes of plastic packaging produced annually, for instance, just 10 per cent is recycled. About a third of all plastic packaging “leaks” into the environment, littering the land or sea.

Beyond beach clean-ups, retrieving plastic from the sea was long deemed implausible. One idea discussed by environmentalists was to tow giant nets behind ships to “fish” for the plastic far from shore — but it would use lots of energy, harm sea life and take hundreds of years to complete.

Slat tells me that he decided “to investigate a problem that people told me couldn’t be solved”. His big idea was passivity. Why move through the ocean if the ocean can move through you? While still at school, as a science project he drew up a plan for a floating barrier in the sea that would act as a filter, catching the bigger bits of plastic but allowing smaller pieces — and organisms — to pass underneath.

Two years later, Slat began studying aerospace engineering at Delft University of Technology. Plastic remained at the forefront of his mind. Six months into his course, he dropped out to turn his idea into a reality.

The challenge Slat has taken on is to gather up, remove and recycle an immense amount of plastic from the “Great Pacific Garbage Patch”, a giant vortex of rubbish in the North Pacific that covers an area twice the size of the UK. “Patch” is a misnomer; the plastic is spread at a low concentration over a vast gyre, a system of ocean currents that spirals around a central point. There are five gyres in the world, each of which accumulates a huge amount of garbage. Slat chose the North Pacific because it is estimated that about a third of all the plastic in the oceans can be found there.

He remembers a day in 2013, soon after dropping out, when he emailed 300 companies asking for $10,000 in sponsorship to get his project off the ground. He got one reply and no funding.

“My initial drive came from the fact that this seemed like an insurmountable challenge and I like thinking about insurmountable challenges,” he says.

Slat is skinny, with a mop of chestnut hair and bright blue eyes. I first meet him one fine morning in June, at an event in The Hague marking the launch of a €1.5m prototype barrier off the coast of the Netherlands in the North Sea. After his initial struggle for sponsorship, he had turned to crowdfunding, and raised more than $2m through the website Indiegogo and ABN Amro’s “Seeds” crowdfunding platform. In 2013 he set up The Ocean Cleanup, a research and development foundation headquartered in Delft, with a few volunteers; today there are 45 employees.

The venue for the prototype launch event is a theatre overlooking the harbour, with rows of folding plastic chairs arranged to face a stage. In attendance are government officials, television crews and researchers from around the world. Anticipating that there will be little time for lunch, Slat swigs from a flask of Huel, a “nutritionally complete” meal-replacement drink.

Shortly before 11am the Netherlands’ minister for the environment, Sharon Dijksma, walks onstage to say a few words. (The Dutch government is co-sponsoring the prototype test, splitting the €1.5m cost equally with deep-sea dredging company Boskalis and an anonymous donor.) “I don’t have to convince this audience that plastic doesn’t belong in our oceans. There’s no confusion on this point,” Dijksma says. The way to combat pollution is to “step up recycling and increase consumer awareness” and clean up the “plastic soup”. She turns to Slat, who is in the front row. “Young people like you fill me with hope for the future,” she says, beaming. “You saw a problem and you are doing something about it, and with your passion you have persuaded people all over the world to join you.”

A short video of the Ocean Cleanup’s 30-vessel “mega expedition” last year to map the scale of the Great Pacific Garbage Patch is shown. Slat gets up to speak. He stands centre stage with a hands-free mic and the air of someone not entirely in their comfort zone. Later he tells me that this “front-end work” — public speaking, media interviews and soliciting sponsorships — is the part of the job he likes least. “What I like best is sitting in a room together with really smart engineers thinking about a problem,” he says.

Some of the 1.5 million pieces of plastic retrieved from the sea during the Ocean Cleanup expedition to the Great Pacific Garbage Patch in 2015 © Raimond Wouda

Slat welcomes everyone to the launch. “Can we build a system which is able to survive on the ocean for years?” he asks. “That is the key question we are trying to answer here with the North Sea prototype.”

The 100-metre barrier, dubbed “Boomy McBoomface”, will be anchored 23 kilometres off the coast of the Netherlands for one year. Resembling a line of black pillows linked together like sausages, the barrier is two metres tall: one metre floats on the surface and one metre is submerged. Made from layers of vulcanised rubber and polyester, it is strong enough to survive loads of up to 80 tonnes — the equivalent of a row of small cars ramming it at once — as well as the bite of any passing sharks. Since the North Sea is more volatile than the Great Pacific Garbage Patch, if it survives there, Slat explains, it can survive anywhere.

Of the 78 million tonnes of plastic packaging produced each year, just 10 per cent is recyled © Raimond Wouda

In 2020 Slat hopes to anchor a 100-kilometre V-shaped barrier in the sea between California and Hawaii, positioned against the prevailing current so that the wind and waves do the work of ushering the plastic against it. Once caught, the waste will bob along the boom towards the V centrepoint, to be hauled out and shipped to shore every six weeks. Slat thinks that in a decade he could clear about 50 per cent of the garbage patch this way.

While oceanographers agree that more should be done about plastic pollution, many are sceptical of Slat’s approach. Even if they applaud his verve, to some he seems more concerned with pursuing his own vision than with adhering to science. Given the sheer amount of plastic that continues to be dumped in the ocean, a clean-up is, some say, at best futile and at worst a distraction from the more pressing issues of waste management and prevention.

How it works: floating barriers made of layers of vulcanised rubber and polyester are designed to catch and concentrate ocean debris, using natural currents © Raimond Wouda

In the past 50 years, the world’s annual plastics production has increased twentyfold, from 15 million tonnes in 1964 to 311 million tonnes in 2014. Last year, a team of scientists led by Jenna Jambeck of the University of Georgia calculated that the amount of plastic that entered the oceans in 2010 was about 8 million tonnes. That is the equivalent of five plastic shopping bags stuffed with plastic for every foot of coastline in the world — and the amount is on course to double by 2025.

All this plastic is not good for the sea. “Think of it as plastic smog,” says Marcus Eriksen, oceanographer and co-founder of 5 Gyres, a non-profit research institute. Yet there is little impetus globally to clean it up. Ownership is difficult to ascribe since much of the plastic is “nonpoint pollution” — meaning that its sources are too plentiful to identify — and in international waters. The nations discharging the highest mass tend to be those with rapid growth and poor waste management. Jambeck’s paper estimates that China is responsible for between 1.3 million and 3.5 million tonnes, or about 28 per cent of the total volume of plastic entering the sea each year.


The more buoyant and hardy plastics leave the shore and accumulate in the gyres. Charles Moore, an oceanographer and captain of the research vessel Alguita, was one of the first to describe this phenomenon in the North Pacific Subtropical Gyre (site of the Great Pacific Garbage Patch).

“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,” Moore wrote in Natural History magazine in 2003. “In the week it took to cross the subtropical high, no matter what time of day I looked, plastic debris was floating everywhere: bottles, bottle caps, wrappers, fragments.”

General consumer detritus found in the sea © Raimond Wouda

The garbage patch may seem like the logical place to start an epic clean-up but research suggests the opposite may be true. In January, researchers from Imperial College London published an analysis which found that collecting plastic waste from coastal areas would have a greater impact. Using a model of ocean plastic movements, Erik van Sebille and Peter Sherman calculated that by placing collectors close to the shore, particularly near China and Indonesia, 31 per cent of particles smaller than 1mm — “microplastics” — could be removed from the North Pacific in 10 years, compared with 17 per cent if the collectors were placed in the Great Pacific Garbage Patch alone.

I ask Slat why he began in the middle. Lots of people are already working on pollution prevention in coastal regions, he says. And besides, if you can develop a technology that works in the deep sea, it would be relatively easy to adapt it to the shore. Also, the plastic in the gyre is persistent. “It won’t clean itself,” he says. “It will only become more dangerous over time as it crumbles into smaller pieces which have a larger chance of getting digested [by marine life].”

Pellets made from recovered plastic as part of the Ocean Cleanup’s research into recycling © Raimond Wouda

Though plastic pollution can now be reliably mapped, there are many unknowns about its impact on marine ecology — and on us. “We have absolutely no concrete evidence that microplastics in the oceans is harming human health at present,” says Tamara Galloway, professor of ecotoxicology at the University of Exeter. “But if we look at everything we know about particles, chemicals and toxins, we’ve got lots of reasons to be concerned.”

Studies have found that a wide range of organisms eat microplastics, including zooplankton and other species at the bottom of the food chain. The toxins that attach to microplastics, called persistent organic pollutants (POPs), “bioaccumulate” as they are carried up the food chain, potentially contaminating the fish and crustaceans that humans eat. POPs are attracted to plastics because they are “hydrophobic”, meaning water repels them. Contaminants found on microplastics include dioxins, which can cause reproductive and developmental damage, and DDT, a pesticide that due to health and environmental concerns is banned globally.


Slat was born in 1994 and raised by his mother, who works in expatriate relocation services; his father, an artist, lives in Croatia. He is an only child. “When I was 12 years old, I was really into chemistry and rocketry,” he tells me.

We are on the deck of the Estrella, an old passenger ferry. The Ocean Cleanup has chartered the boat to take a group of journalists out to witness the prototype being anchored into place. There was a storm during the night and the sea is the colour of pencil lead, but as we near the prototype the sun comes out. Slat dons sunglasses and pours bottled water into a glass to drink. “I’ve already let them know that next time we shouldn’t use plastic bottles,” he says, smiling.

Slat thinks that the degradation of the environment is one of the big problems of our time. “When you look at the humanitarian issues — poverty, education, rights, violence — I think there are positive trends,” he says. “But when you look at climate change, at plastic pollution and other forms of pollution, at overconsumption, it’s a different story.” He believes in the power of science and technology to resolve society’s ills. He admires Elon Musk’s “capacity to get stuff done” and Silicon Valley’s “fail fast” axiom. He subscribes to iterative design principles, a methodology based on a cyclical process of prototyping, testing, analysing and refinement — of hits, misses and tweaks. The North Sea prototype is one step in a multi-phase plan that is marching towards the 2020 Pacific Ocean deployment. In 2017 the team aims to plant a pilot barrier in the Korea Strait near the Japanese island of Tsushima.

Journalists and Ocean Cleanup staff on board the Estrella in June © Raimond Wouda

Slat is the first to admit that, “looking back, I didn’t know what on earth I was doing” but says his “obsessiveness” means he finds a way. However, his lack of experience has led to misgivings among oceanographers already wary of the hype around the project. His talk at a Tedx conference in Delft in 2012 has been viewed more than 2.5 million times, and media coverage has been breathless. One headline, in the Huffington Post, declared: “21-Year-Old’s Miracle Ocean Cleaning Tech Ready To Get Its Feet Wet.”

There are also questions about the Ocean Cleanup’s funding model. Slat says he doesn’t yet know how the deployment of the 2020 barrier will be paid for but hopes to attract more corporate sponsorship and to receive contributions from governments. “It would make sense for governments to be involved because it’s a tragedy of the commons,” he says. The Ocean Cleanup is also researching the feasibility of recycling ocean plastic. “What we’ve seen is that there is a large amount of companies who are interested in buying this material once it’s been taken out of the ocean.”

“I don’t think [Slat’s project] will ever be deployed in the deep ocean,” says oceanographer Moore. “His thinking is that there will be a market for this kind of device and he’s going to sell it, but the plastic is just not valuable enough.”

Moore is in his sixties and lives in Long Beach, California. When I call, he answers the phone with “Captain Moore speaking.” He is not an Ocean Cleanup fan. He knows Slat and calls him a “prodigy” but says the project offers the “false promise” that the ocean can be restored to a pristine state. Few researchers have spent as much time in the Great Pacific Garbage Patch as he has. “I’ve been out there observing, feeling the change and witnessing the change, and it’s dramatic,” he says. “It’s horrifying to see our ocean over millions of square kilometres become an ugly mess of waste.”

Slat’s prototype barrier © Raimond Wouda

Sea turtles, albatrosses, whales and fish are bad at distinguishing between plastic and food. Hundreds of species are known to either ingest or become entangled in marine debris. In the stomachs of four sperm whales that beached in Tönning, Germany, in January, researchers found a 13-metre fishing net, a car engine cover and the remains of a bucket. “What will happen if you create a linear barrier is that every creature in [that part of] the ocean is going to go to that barrier to feed, and they will be feeding on plastic,” Moore warns. I suggest that if plastic is left in a garbage patch then marine creatures will eat it anyway, and that removing it will at least mean it spends less time in the sea, lessening the encounter rate. “That will have to be his argument,” Moore concedes. “But the negative far outweighs the positive.”

It is what the Ocean Cleanup signals to the world that troubles Moore: that there is no need to worry about plastic spilling into the sea since Slat will clear it up. “Techno-fixes are the way we deal with our problems. It’s a kind of hubris that we have as a species,” he says. “We think we can fix any problem we create.”

While scientists learnt long ago how to string together hydrocarbon molecules to form plastic, they have not yet figured out how to reverse the process: how to break polymers down into basic elements again. The Ocean Conservancy estimates it takes 450 years for a plastic bottle to decompose; leather or tin cans are gone in 50. It seems perverse that something with this amount of endurance has become the material of choice in our consumer-centric, throwaway epoch. Shopping bags, yoghurt pots, coffee-cup lids — all are called disposable but are engineered to persist.


Julia Reisser photographed in the tropical-themed meeting room at Ocean Cleanup’s Delft HQ © Raimond Wouda

There is growing consensus among government ministers, think tanks, NGOs and scientists that the only way to reduce marine debris is to overhaul the plastics industry. A report presented at the World Economic Forum in January titled “The New Plastics Economy: Rethinking the Future of Plastics”, by the Ellen MacArthur Foundation with analysis from McKinsey, suggests the current “linear” economy of “take, make, dispose” belongs to the past. Since most plastic packaging is used only once, 95 per cent of its value, some $80-$120bn, is lost annually. Applying “circular economy” principles to the plastics industry by creating “effective after-use pathways” — improving reuse, recycling and designing products with recovery in mind — could drastically reduce ocean leakage. “It’s the circular economy that’s going to save us,” says Moore, “not fancy booms out on the ocean.”

Yet achieving such systemic change will require collaboration between all stakeholders across the global plastics value chain, from policymakers to consumer-goods companies, plastic producers and businesses involved in collection and processing. (Persuading plastic producers to get behind an idea that will reduce demand for plastic could be especially tricky.) In the meantime, says the Ocean Cleanup, is it not worth doing something?

The day after our boat trip, I meet Julia Reisser, 31, the Ocean Cleanup’s lead oceanographer, at the organisation’s Delft HQ. The offices are decorated in the cheerful manner of student halls; one meeting room has a hammock and a Hawaiian theme. Staff, mostly in their twenties and thirties, buzz about.

Equipment used in Reisser’s lab to weigh plastic waste © Raimond Wouda

Originally from Brazil, Reisser was completing a PhD on microplastic pollution in Australia when she heard about the Ocean Cleanup. Last year she led 30 vessels fitted with trawls on the expedition to the Great Pacific Garbage Patch. “It was a 30-day expedition but, 10 days in, all my containers were full,” she says. “We were like, whoa, we were wrong — there is far more plastic than we predicted.” A manual count of the plastic caught on the expedition revealed a total of 1.5 million pieces. Analysis found that 90 per cent of the total mass of plastic in the garbage patch was “locked” in pieces bigger than 10cm. “By collecting the larger items, what we are doing is avoiding a huge increase in microplastic concentrations in the decades to come,” Reisser explains.

On a workbench in her lab are the contents of a trawl. Bottle caps fill a foil tray. Another tray holds dozens of nurdles, the pea-sized pellets of “raw” plastic that manufacturers melt down to mould into products. There is polystyrene packaging, a bleached crate, bundles of blue fishing net and the white ellipse of a toilet seat. Carefully laid out in groups, these look like an ad hoc exhibition. From one angle, they are fascinating, even beautiful; from another, a visual indictment of our consumer age.

Photographs: Raimond Wouda

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