In 2014, the boom design was revised, replacing 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 long. In 2015, this design won the London Museum Design of the Year and the INDEX: Award.





Charles Moore, the man who first discovered the now infamous Great Pacific Garbage Patch in the North Pacific Subtropical Gyre, has famously claimed that cleaning it up would be impossible: “Trying to clean up the Pacific gyre would bankrupt any country and kill wildlife in the nets as it went”, he’s proclaimed.


And there’s no denying that the plastic-ridden expanse of the North Pacific, the largest of five oceanic gyres where plastics collect in slowly rotating currents, is a challenging environmental nightmare, one that can’t be fixed with a fleet of carbon-emitting and net-dragging boats. The Algalita Marine Research and Education Foundation, where Moore works, describes the garbage patch as ‘a “plastic soup”, where the plastic is distributed throughout the water column’, taking up an area of the ocean roughly two times the size of Texas. With most of the plastic broken into small pieces through exposure to the sun’s ultraviolet radiation, the foundation presents this disheartening analogy for those ambitious enough to think it can be cleared: ‘Think of how difficult it would be to gather confetti from along a stretch of beach. Now imagine the area you are trying to clean is not only miles long, but also miles deep.’


The photodegraded plastic, which outnumbers plankton by a ratio of six to one, is often mistaken as food by marine life and, even when it doesn’t directly kill those that ingest it (and it reportedly kills at least a million sea birds and hundreds of thousands of marine mammals each year), it can enter the food chain, bringing with it a whole host of undesirable chemicals – hormone disrupters like bisphenol A and potential carcinogens like styrene monomers – that the plastic releases as it degrades, as well as hydrophobic fertilizers and herbicides that it absorbs in the marine environment.


It’s a bit of an overwhelming problem, and, with environmental dilemmas like this, “the common response is ‘Well, that’s a long way off. That’s for our children to worry about’”, according to Boyan Slat. Speaking in the video of his TEDx talk in his home city of Delft, Netherlands, Slat follows that assertion with a cheeky grin and the statement: “Hello. Here I am.”


At the time of giving his talk, Slat was just 17 years old and was presenting his concept for a passive oceanic cleanup system, which grew out of a high school science project. Slat explains: “I realised, back in high school, that there might be an alternative [to a cleanup process based on vessels with nets that would be fishing for plastic]. I wondered: why move through the oceans if the oceans can move through you? Instead of going after the plastics, you could simply wait for the plastic to come to you, without requiring any added energy. An array of floating barriers would first catch and then concentrate the debris, enabling a platform to efficiently extract the plastic afterwards. The ocean currents would pass underneath these barriers, taking… sealife with it, preventing by-catch. An elegant idea. But when I got asked to present this idea at the TEDx Delft conference, it wasn’t much more than that – an idea.”




LIMITATIONS - Though The Ocean Cleanup estimates it can collect the majority of plastic mass from the world’s oceanic gyres, it does not think it can collect any microplastics, particles less than five millimetres (mm) (or even one mm, according to some researchers). In fact, under the modelled conditions, no plastics smaller than two centimetres were captured.

“There appears to be a sink for microplastics that is already in place”, Slat tells me. “We don’t know what it is, but it could be that fish are eating it and therefore they cannot be found anymore near the surface of the water – there should be a lot more of them, but there aren’t. It could also be that they sink, that they are deeper in the water column – we have some evidence for that.”

Slat emphasises that, by capturing 95 per cent of the mass of oceanic plastic, The Ocean Cleanup would prevent many microplastics from being created, as larger plastic items photodegrade into ever-smaller pieces in pelagic conditions. However, microplastics don’t just come from larger bits of plastic – some start off micro, which is of increasing concern to scientists and environmental campaigners.



After presenting his idea at TEDx, Slat started studying aerospace engineering, but, he says he couldn’t stop thinking about ocean plastics and so turned to professors and industry experts to help compile a list of 50 questions that needed to be answered to call his idea a feasible solution. He subsequently suspended his studies to set up The Ocean Cleanup foundation, and used crowdfunding and the work of many volunteers and professionals in many fields – including ecology, engineering, fluid dynamics, plastic processing and maritime law – to conduct an extensive feasibility study into the idea. This summer, the foundation released a 530-page report claiming that the idea is indeed feasible.


“The basic concept and all the basic principles – so, the catching of the plastics, the concentration of the plastics – haven’t changed and have in fact now been validated, but what has changed now is some of the details”, Slat tells me, adding: “For example, how the mooring systems work, what the platform looks like – at first it looked like a fancy UFO crashed into the ocean; it now more closely resembles an oil rig. Basically, when I made these concept designs, I didn’t have any knowledge whatsoever, there was no one helping me three years ago. Now, fortunately, having worked with a team of 100 people, including 70 scientists and engineers – we’ve been able to develop this.”


It’s mainly the details that have changed, and, Slat says, they now have more accurate estimates for many aspects of the project. The study conservatively estimates that there are 140,000 tonnes of plastic floating in the North Pacific gyre – 119,000 tonnes of particles larger than two centimetres and 21,000 tonnes smaller than two centimetres. Most of this plastic, according to the study, is concentrated close to the surface of the water, with mass decreasing exponentially with depth, leading to the conclusion that the floating barriers should be placed at a depth of two to three metres to collect the greatest mass of plastic pollution. 


The design of these floating booms has also changed, as tests found that long booms with high tension wouldn’t be able to work with the movements of the waves, and in fact could ‘overtop’, likely losing some of the plastic collected. The Ocean Cleanup has attempted to address the problem with a design that sees boom and tension cable separated, with booms connected to the cable every 60 metres. The booms are comprised of floating buoyancy elements with weighted ‘skirts’ – thin, impermeable and flexible sheets that direct the plastics – hanging to a depth of two to three metres. They will be positioned in a ‘V’ shape, and angled toward a central platform with the aim of concentrating the plastic; the models show that 80 per cent of the plastic that encounters the booms will be captured. It will then collect at the moored processing platforms that Slat says look like oil rigs (though some might think they’re remarkably like air traffic control towers anchored to the sea floor), from which it will have to be picked up by ship every 45 days.


Slat explains that this system is highly scalable and that the percentage of plastics that it can capture depends on the scale of deployment: “If you deploy a single system with a length of a hundred kilometres, you would collect 42 per cent of the plastic in the Great Pacific Garbage Patch, where about a third of all plastics from all oceans combined can be found. But if you deploy something that’s, say, 200 kilometres, you would collect about two-thirds of the Great Pacific Garbage Patch. If you use a hundred-kilometre device and deploy it for 20 years, you would collect about 75 per cent, so it really depends on these variables. We can say that the majority of plastics in this area can be collected using this system.”


And it’s not just the collection of plastic that the foundation is looking into – it’s also considering what to do with the harvested material. The feasibility study involved collecting half a tonne of plastic from a remote Hawaiian beach, considered to be a ‘representative’ sample of gyre debris. This waste was tested by pyrolysis companies, which found that ‘the quality of the pyrolysis oil obtained from the polyolefin fraction of marine debris is comparable to that obtained as regular input in their pyrolysis plants’. The cover of the 530-page feasibility document itself was also made using ocean plastics treated with a heat press. Slat proudly displays the finished product saying: “You can still see that it’s made out of ocean plastic because you have these weird colours that look kind of cool.”




MICRO BEAD BAN - ‘Primary microplastics’ are popular in beauty products as abrasives and exfoliants, especially in face washes, toothpaste, shaving cream and shower gel – and these microbeads are now commonly made from plastic rather than natural materials (be sure to read your ingredient list!). Microplastics can also originate in household washing machines, due to the shedding of synthetic textile fibres – in either case, these tiny bits of plastic are too small to be extracted by sewage treatment works, and slip through to marine ecosystems with devastating consequences.

While there’s little that can currently be done about microplastics that break away from larger masses, there’s now an international campaign, ‘Beat the Microbead’, which was launched by the Plastic Soup Foundation in 2012. As a result, a number of multinational cosmetic companies have pledged to phase out microbeads, though many have not set definite timetables. Moreover, the Dutch government is pushing for a ban in Europe, which would be similar to bans in some US states; following concern about microplastic dispersion in the Great Lakes, Illinois and New York have banned the manufacture and sale of products containing microbeads, with Michigan and Ohio looking to follow suit.



Since completing the study, Slat tells me, they have also done some experiments into recycling the plastic through injection moulding, and that “the quality by far exceeded our expectations”. “The injection moulding was 50 per cent polypropylene, 50 per cent polyethylene. The only preprocessing was washing to remove any organic contaminants. Of course, it will certainly be downcycling in a way because you can’t use it for food packaging, and we’re still doing some chemical analysis of it to see if there’s any contamination that we should worry about.” That being said, he still anticipates any number of things could be made out of the material – “computer screens or chairs or anything you can imagine”. 


Putting the plastic to good use will also offset some of the costs of the project, and perhaps even make it profitable: “Because of the premium of it being ocean plastic, I think there’s definitely a market for it, and I’m confident that it can cover at least part of the costs of the execution”, Slat says. The study estimates that it would cost €317 million (£247.5 million) to remove 42 per cent of waste from the North Pacific Gyre over 10 years; to break even, the project would need to receive €4.53 (£3.54) per kilogramme of collected plastic.

But all this is still a few years off. Following the triumphant launch of the feasibility study, The Ocean Cleanup created another crowdfunding campaign, this time seeking US$2 million (£1.2 million) to proceed to the next phase of testing. When I spoke to Slat several days before the deadline, the pledges were still US$70,000 (£42,900) short, and the situation was “rather tense”, though he assured me the research would continue with or without the funding, albeit at a much slower pace in the latter case. As it happened, the campaign raised more than US$2.15 million (£1.32 million), making the next steps much easier. 

“Now, we’ll start the pilot stage and through a series of upscale tests, we’ll work towards this large-scale operation of a pilot in about three to four years’ time”, Slat explains. “We’ve shown that the concept is likely feasible, but now we have to also make it executable. There are some factors that primarily influence the costs as well as the efficiency. So, there is a large uncertainty of the amount of plastic in the area, so that’s something that we will be working on. And then there’s the variability of the current, which will likely influence the collection efficiency. In the next year, we will mostly be doing controlled environment tests, then we’ll go to coastal waters and then in two years’ time, we’ll be ready to go to the centres of the gyres to do tests there and deploy a large-scale device. That should be the final stepping stone before actually doing it on the full scale.”

In the coming years, The Ocean Cleanup will also be continuing to emphasise the importance of preventing plastics from reaching the oceans in the first place: “Just because we have a way to clean up what’s already out there, it shouldn’t be an excuse to continue pollution, but now should be the time that we really do our best to make sure that the tap is closed, as well”, Slat says, and indicates that the project could also look at ways to intercept plastic before it reaches the ocean.

So there is still a lot of work to be done, but there are certainly reasons to be optimistic. And even the famous Garbage Patch discoverer and cleanup naysayer isn’t overly pessimistic about the project’s prospects: Slat tells me he had “a wonderful four or five hour discussion” with Charles Moore about his concept, and the captain “wasn’t too negative about it” (though he was “definitely sceptical”).


“Human history is basically a list of things that couldn’t be done and then were done”, the tireless and optimistic young man proclaimed when launching the feasibility study. Here’s hoping we can soon add cleaning up the oceans to that list. By Libby Peake



Wilson 01 the ocean cleanup floating boom scooper





Boyan Slat is a 20-year-old on a mission - to rid the world's oceans of floating plastic. He has dedicated his teenage years to finding a way of collecting it. But can the system really work - and is there any point when so much new plastic waste is still flowing into the sea every day?

"I don't understand why 'obsessive' has a negative connotation, I'm an obsessive and I like it," says Boyan Slat. "I get an idea and I stick to it."

This idea came to him at the age of 16, in the summer of 2011, when diving in Greece. "I saw more plastic bags than fish," says Slat. He was shocked, and even more shocked that there was no apparent solution. "Everyone said to me: 'Oh there's nothing you can do about plastic once it gets into the oceans,' and I wondered whether that was true."

Over the last 30 to 40 years, millions of tonnes of plastic have entered the oceans. Global production of plastic now stands at 288 million tonnes per year, of which 10% ends up in the ocean in time. Most of that - 80% - comes from land-based sources. Litter gets swept into drains, and ends up in rivers - so that plastic straw or cup lid you dropped, the cigarette butt you threw on the road… they could all end up in the sea.

The plastic is carried by currents and congregates in five revolving water systems, called gyres, in the major oceans, the most infamous being the huge Pacific Garbage Patch, half way between Hawaii and California.

Although the concentration of plastic in these areas is high - it's sometimes described as a plastic soup - it's still spread out over an area twice the size of Texas. What's more, the plastic does not stay in one spot, it rotates. These factors make a clean-up incredibly challenging.

"Most people have this image of an island of trash that you can almost walk on, but that's not what it's like," says Slat. "It stretches for millions of square kilometres - if you went there to try and clean up by ship it would take thousands of years." Not only that, it would be very costly in terms of both money and energy, and fish would be accidentally caught in the nets.

Slat had always enjoyed working out solutions to puzzles, and while pondering this one, it came to him - rather than chase plastic, why not harness the currents and wait for it to come to you?

At school, Slat developed his idea further as part of a science project. An array of floating barriers, anchored to the sea bed, would first catch and concentrate the floating debris. The plastic would move along the barriers towards a platform, where it could then be efficiently extracted. The ocean current would pass underneath the barriers, taking all buoyant sea life with it. There would be no emissions, and no nets for marine life to get entangled in. The collected ocean plastic would be recycled and made into products - or oil.



Boyan Slat on the docks at Rotterdam



The high school science project was awarded Best Technical Design at Delft University of Technology. For most teenagers, it would probably have ended there, but Slat was different. He had been interested in engineering from a very young age. "First I built tree houses, then zip-wires, then it evolved towards bigger things," he says. "By the time I was 13, I was very interested in rocketry." This led him to set a Guinness World Record for the most water rockets launched at the same time: 213, from a sports field in his native Delft. "The experience taught me how to get people crazy enough to do things you want, and how to approach sponsors." Useful skills, as it turned out.


When Slat began studying aerospace engineering at Delft University, the idea of cleaning up the oceans just wouldn't let him go - he says it niggled at him like "an asymmetrically positioned label" on a pair of boxer shorts. He set up a foundation, The Ocean Cleanup, and explained his concept in a TedX Talk: How the Oceans can Clean Themselves. Then, six months into his course, he made the decision to pause both university and social life to try make it a reality.


His entire budget consisted of 200 euros (£160) of saved-up pocket money, so he spent a few desolate months trying to get sponsorship. "It was so disheartening, because no-one was interested," he says. "I remember one day contacting 300 companies for sponsorship - only one replied, and that, too, resulted in a dead end."


But then something happened. On 26 March 2013, months after it had gone online, Slat's TedX talk went viral. "It was unbelievable," he says. "Suddenly we got hundreds of thousands of people clicking on our site every day. I received about 1,500 emails per day in my personal mailbox from people volunteering to help." He set up a crowd-funding platform that made $80,000 in 15 days.

Slat still doesn't know what made his idea take off like that, but he describes it as a great relief. "A year ago I wasn't sure it would succeed," he says. "But considering the size of the problem it was important to at least try."

The amount of plastic being discarded into the marine environment is such that we could eventually see an ocean where the amount of plastics is roughly one third the total biomass of fish - 1lb of plastic for every 2lbs of fish, according to Nicholas Mallos from Ocean Conservancy, which organises coastal clean-ups.

According to the UN Environment Programme there are on average 13,000 pieces of floating plastic per square kilometre of ocean - but that goes up to millions of pieces in the gyres. Many of these particles end up being accidentally ingested by marine animals, which can die of starvation because of the plastic filling their stomachs.


Albatrosses are particularly vulnerable because they feed on the eggs of flying fish, which are attached to floating objects - now most likely a piece of plastic. Dr Jan Andries van Franeker from the Institute for Marine Resources and Ecosystem Studies (IMARES) in the Netherlands has some of these objects in a pot in his office: a toothbrush, cigarette lighters, floaters from fish nets, a golf ball, a tampon applicator - all found in albatross chick's carcasses. "The plastics may not directly kill the bird, but it will have less energy reserves and it will have a higher load of chemicals so if things get problematic at sea, or if you have to raise a chick, those are the ones that die first," he told the BBC.


Turtles tend to be the victims of plastic bags, which when immersed in water look just like jellyfish. Evolutionary adaptations make it impossible for turtles to reject bags once they've started to eat. "Because jellyfish are so slippery, turtles have a system in their throat that stops their prey from slipping out, so even if you find out it's a plastic bag, it has to go in all the way," says van Franeker.


The amount of industrial plastic pellets van Franeker finds in the birds has halved since the 1980s - it seems the industry has at least partially cleaned up its act. "It's an economic loss if the factory loses raw product," he says. "Unfortunately with consumer plastic, there is little profit in taking back waste. It doesn't cost us anything to throw it away."

But the cost to us could be very high, in the long term.

Plastics can act as a sponge and soak up chemicals in the water. "There are a lot of pollutants in the oceans now, things like DDT," Nancy Wallace, director of the US National Oceanic and Atmospheric Administration's Marine Debris Program, told the BBC. "Those chemicals adsorb on to the plastic and we know birds and fish are eating those pieces of plastic - so the question is, how does that transfer up the food chain and what is the impact?"


It is a grave situation - so when Slat came along with a seemingly simple solution, he began making headlines across the world. Could a teenager save the world's oceans? His enthusiasm fired up millions of people, but along with the offers of help and donations, came criticism. It wouldn't work, some said. Others argued that it would be better to collect litter from beaches, where it gets deposited by waves.


"It's in my nature that when people say something is impossible I like to prove them wrong," Slat says. Having caught the world's attention, the first thing he did was to disappear from sight. He needed scientific evidence to back up his theory and answer his critics.

He assembled a team of 100 people, mostly volunteers, who were spread out across the world - the lead oceanographer was based in Australia. To manage so many people at such a young age was "interesting", says Slat. "We had an intern who was 24 and we weren't too satisfied with him - I remember some colleagues saying: 'Oh, he's so young, he'll learn,' not realising that they were talking to a 19-year-old."

During the feasibility study Slat visited the gyre known as the North Atlantic Garbage Patch, where the platform is destined to be built. "I was pretty seasick the first three days. There were winds of 25-30 knots and waves 3m high. It was quite an experience," he says.


In June, a month before his 20th birthday, Slat re-emerged with a 530-page feasibility report, the cover of which was made out of recycled ocean plastic. The report, based on extensive testing and computer simulations and authored by 70 scientists and engineers, answered many of the questions which had been levelled at him by his critics. It was followed by another crowd-funding campaign which swiftly reached its target of $2m. This will fund a larger pilot next year and Slat hopes the North Atlantic platform could be a reality in 2020.

But if Slat expected all experts in the field of ocean plastics to welcome his concept this time, he was wrong.





The Ocean Cleanup is non-government engineering environmental organization based in Netherlands, that develops technology to extract plastic pollution from the oceans.





Boyan Slat is not alone in the fight against ocean plastic. These emerging technologies could all play a part in containing the mountain of plastic that is accumulating on the oceans floors, by recovering floating debris before it sinks. New ideas are welcomed.








2012 - TED Talk

2013 - Company Formation

2014 - Concept Revisions

2015 - Scale Model Tests

2016 - North Sea Trial

2017 - Pipe Size Reduction

2018 - Wilson & Scale Test

2019 - Sea Trials Pacific

2019 - River skimming barges

2020 - The Future

2021 - Qualified success Sept 16 (Reuters)





* Aliance to end Plastic Waste

* Boyan Slat's ocean booms

* 4Ocean recycled plastic bracelets

* Kulo Luna graphic novel

* Ocean Voyages Institute

* Ocean Waste Plastic

* Seabin

* Sea Litter Critters

* SeaVax autonomous drones

* World Oceans Day











WIND AND WAVES - The floating boom systems are designed to capture plastics ranging from small pieces just millimeters in size, up to large debris, including massive discarded fishing nets (ghost nets), which can be tens of meters wide.

Models show that a full-scale cleanup system roll-out (a fleet of approximately 60 systems) could clean 50% of the Great Pacific Garbage Patch in just five years.

After fleets of systems are deployed into every ocean gyre, combined with source reduction, The Ocean Cleanup projects to be able to remove 90% of ocean plastic by 2040.

The system consists of a 600-meter-long floater that sits at the surface of the water and a tapered 3-meter-deep skirt attached below. The boom floater provides buoyancy to the system and prevents plastic from flowing over it, while the skirt stops debris from escaping underneath.

Both the plastic and system are being carried by the currents. However, wind and waves propel only the system, as the floater sits just above the water surface, while the plastic is primarily just beneath it. The system thus moves faster than the plastic, allowing the plastic to be captured.

It's a giant version of fishing nets as used for centuries by fishermen. A secondary net and modified fishing vessels then capture and land the plastic on a vessel where it is transported to land for recycling.













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