Boyan Slat has spent his teenage years on a mission to clean the World’s oceans. His invention, which began as a school science project was triggered by his own experiences of the problem of plastic pollution in the sea around Greece.
Previous thinking has always been that it is a fruitless task to try to clean the ocean. The areas clogged with plastic debris are so vast, that it was estimated that cleaning one single ‘garbage patch’ would take in the region of 79,000 years using vessels and nets to catch the particles.
Unfortunately, this vessel and net technique would cause real harm to sea life who could easily be caught up in the nets. The ships would also release CO2 into the atmosphere, causing further environmental damage. Slat decided to think outside of the box and came up with a revolutionary concept.
The video below shows an 18 year old Slat hosting a TEDtalk which discusses his ideas. He “combines environmentalism, entrepreneurism and technology to tackle global issues of sustainability. After diving in Greece, and coming across more plastic bags than fish, he wondered; “why can’t we clean this up?””
“Taking care of the world’s ocean garbage problem is one of the largest environmental challenges mankind faces today. Not only will this first cleanup array contribute to cleaner waters and coasts but it simultaneously is an essential step towards our goal of cleaning up the Great Pacific Garbage Patch. This deployment will enable us to study the system’s efficiency and durability over time.” ~ Boyan Slat, founder and CEO of The Ocean Cleanup”
A study by Jambeck et al published in 2015 reported that approximately 8 million tonnes of plastic makes its way into the ocean each year. There are 5 hot spots known as gyres, where the floating debris tends to accumulate.
Eriksen et al, 2014 estimate that there are at least 5.25 trillion pieces of plastic in the oceans! They take the form of packaging, carrier bags, toothbrushes, toys, tampon applicators, pellets and anything else that we carelessly discard.
The Pacific Garbage Patch is one of the most notorious collections of floating marine debris. It spans the space from the West Coast of North America across to Japan – an area roughly the size of Texas. It consists almost entirely of tiny micro plastic particles, which create a kind of plastic soup. Cozar et al, 2014 have reported that around a third of the Ocean’s plastic pollution converges here.
Seabirds and marine animals are particularly vulnerable to plastic debris – with a reported 1,000,000 sea birds and 100,000 mammals (Laist 1997) dying each year as a result of ingesting, poisoning, entrapment and other plastic related causes.
The albatross is attracted to eating red plastic particles, and also accidentally consumes debris which becomes attached to flying fish eggs.
Plastic bags also pose a terrible threat to turtles. They can look very similar to jellyfish when under water. Sadly the turtles are unable to reject the plastic bags once they start to eat them, because of biological nuances that have adapted over times. Dr Jan Andries van Franeker from the Institute for Marine Resources and Ecosystem Studies (IMARES) explains: “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.”
A secondary problem with the micro plastic particles is that they soak up many chemicals which leak into the water cycle. Nancy Wallace, director of the US National Oceanic and Atmospheric Administration’s Marine Debris Program says: “There are a lot of pollutants in the oceans now, things like DDT. 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?”
The impact could be devastating when we consider that we too are a part of this chain. The toxins become more concentrated as they go up the food chain, meaning that the whole ecosystem will be infiltrated by poison. PCBs and DDTs are some of the more common toxic chemicals absorbed by the plastic. Mato et al 2001 explained that this increased the concentration a million times.
Health risks linked to these chemicals include cancer, hormone disruption and reduced fertility in humans.
Many industries are affected by the plastic pollution that is choking the ocean. Fishing, shipping, tourism and the clean up of coastlines is though to cost $13 billion globally.
Unlike the traditional methods of trawling the ocean with a vessel and nets, Slat has turned the thinking on it’s head. His plan is to harness the Ocean’s own movement to allow debris to come to his clean up stations. The beauty is that it is solar powered too – so there will be no carbon emissions.
It will be the longest floating structure ever created – and is to be shaped like a manta-ray which can move with the currents. It is set to be deployed as soon as 2016!
The roll out may initially take place off the coast of Tsushima, which is a small island located between Japan and South-Korea. This island sees a massive one whole cubic metre of plastic pollution per person washed up on its shores every year. It will be operational for at least two years, and the accumulated plastic could be used as an alternative energy source.
The Ocean Clean Up’s structure will cross an area of 2,000 meters – double the length of the Tokyo Mega Float, which holds the current record for the World’s largest floating structure.
Slat plans to set up more stations over the next five years, with a flagship system intended to span a 100 km stretch between Hawaii and California.
The device is a series of floating booms and processing platforms, anchored into the sea bed. Large floating barriers will use the flow of the ocean itself to clean the plastic pollution – as the current will naturally move under the booms, significantly reducing the sea life that is caught.
The floating barriers will catch the plastic debris, enabling it to be easily flitered and then stored ready for recycling. The following diagrams are taken from the Ocean Clean Up Site and explain the process simply.
Why move through the oceans, if the oceans can move through you? Instead of going after the plastic using boats and nets, The Ocean Cleanup will use long floating barriers, using the natural movement of the ocean currents to passively concentrate the plastic itself.
Virtually all of the current flows underneath these booms, taking away all (neutrally buoyant) sea life, preventing by-catch, while the lighter-than-water plastic collects in front of the floating barrier.
The scalable array of floating barriers, attached to the seabed, is designed for large-magnitude deployment, covering millions of square kilometers without moving a centimeter.
Slat has a team of more than 100 volunteers, including scientists, that have been working tirelessly to research his idea. They have found that:
“using a single 100 km cleanup array, deployed for 10 years, will passively remove 42% of the great pacific garbage patch. We conservatively estimate this to be 70,320,000 kg. This (conservative estimate) would imply a cleanup cost of € 4,53 per kilo.”
So the answer is a resounding YES! This really could work.
Thanks to the motivating TEDtalk (posted at the top of this article) going viral, Slat started to receive thousands of emails from people wanting to contribute.
“It was unbelievable,” Slat 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 decided to set up a crowd-funding platform that made $80,000 in 15 days!
The Pilot Phase was also funded this way – raising a staggering 2.1 million dollars (U.S).
There is also a donation page set up for anyone who would still like to make a contribution.
Slat’s plan is indeed revolutionary and could have a real impact to the Ocean once it gets going. However, there has been a backlash of criticism from the science community.
The main concern is that Slat’s filter doesn’t remove micro plastics. Anything smaller than 2 mm wouldn’t be caught in the system. It must be said that removing the larger debris would result in less micro plastics over time.
Another limitation on the Ocean Clean Up is that is only deals with surface debris, and does not tackle the plastic which is distributed throughout the ocean, at all depths and even the ocean floor.
Prof Richard Thompson of Plymouth University feels that the focus should be on preventing the pollution in the first place:
“It seems a foolish strategy to focus on approaches to take litter out of the oceans, when we could prevent it from getting there in the first place. If I had a sum of money to invest in the problem then I would spend 95% of it on approaches to stop the plastic from entering the oceans. Of course we want to find ways to remove litter but we shouldn’t delude ourselves. It’s like trying to mop up the bathroom floor while leaving the bath overflowing and the taps turned on full.”
The fact is that there is plenty of pollution in the ocean already. Slat recognises that other strategies are required to address the whole problem, but his solution is a huge step in the right direction – and I for one applaud his determination and courage!
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