CLEANING THE OCEAN
Prototype of process to filter the plastic in the Pacific Ocean is being tested
Bottles, bags, tyres, synthetic fibres… Each year millions of tons of plastic are poured into the ocean. Not biodegradable to any helpful extent, often invisible, this rubbish is threatening the marine fauna and progressively entering the food chain. To deal with this pollution, a young Dutchman is testing his invention in the Pacific ocean.
1998, Charles Moore, an oceanographer, was sailing across the North Pacific when he made an unwelcome discovery. “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. “It seemed unbelievable but I never found a clear spot. 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.” What he stumbled on became known as the Great Pacific Garbage Patch or “Pacific trash vortex”. It is thought to be anywhere between the size of Texas (700,000 square kilometers) to several times that size.
2. Most of the plastic waste that ends up in the oceans is thought to become part of these “garbage patches” of rubbish. Described as a “ticking time bomb” by marine scientists, the Great Pacific Garbage Patch is believed to have grown by five times in the past 10 years and will become a greater risk to life as the plastic degrades further. It’s a problem that caught the imagination of a then 16-year- old schoolboy from the Netherlands, Boyan Slat. “I had to do a high-school science project that year and I decided to really dedicate myself to this issue. Everybody told me it would be impossible to clean up, the main problem being that the plastic is extremely dispersed... over a wide area.”
FILTERING OUT PLASTICS
3. The key idea that makes Slat’s concept different to other schemes is the principle of “letting the sea do the work” by having ocean currents run into V-shaped screens that filter out small plastics. When the system is fully operational, the plastics
can then be loaded onto small vessels and taken back to land for recycling. Today the Ocean Clean Up Foundation employs more than 70 people and has around $ 30m (€ 25m) in funding. But the task confronting Slat and his team will require a great deal more than this.
4. Although it’s hard to gain accurate data, today’s estimates suggest roughly five trillion pieces of plastic are now floating in our oceans. Seven million tons are dumped into the sea each year. The Ellen MacArthur Foundation estimates that the volume of plastic waste in our oceans will outweigh the total mass of fish in the sea by 2050.
5. Having tested a prototype model of its system in the North Sea last year, The Ocean Cleanup announced in May that it plans to conduct a trial in the Pacific later this year, and start a full cleanup operation there next spring. “We’re starting with the North Pacific gyre simply because it is the largest accumulation of plastic. A third of all ocean plastic can be found in that area. We’ll gather data and improve the system continuously”.
6. I ask Slat what has troubled him the most about the situation facing our oceans. “Definitely the degradation,” he says. “Plastic doesn’t really go away by itself.” “The concentration of plastic is rapidly increasing in the gyres. Even if you were to close off the tap, and no more plastic entered the ocean, that plastic would stay there, probably for hundreds of years”.
7. Not only a threat to sea life, the degradation of ocean plastics leads to the release of chemicals that are known to be harmful to humans when they enter the food chain. Significant debris can cause damage to shipping, foul up tourist sites and encourage invasive species. Much of our older marine waste is now breaking down into more toxic and hard-to-remove substances, and reaching parts of the sea previously thought to be relatively pristine.
Seven million tons of plastic are dumped into the sea each year.
8. Boyan Slat has other plans as to how the foundation can help solve this problem. “We might work on ways to prevent plastic getting into the ocean in the first place. We published a study in Nature back in June, showing that 86 per cent of the plastic is coming from Asia, and coming from a relatively small number of rivers in those areas. So, in the future, we could do something there within those river mouths.”
Boyan Slat during one of his research expeditions.