Beach Rubish The Ocean Cleanup has been collecting plastic waste using a 600-metre floating barrier. © Claire Sambrook, Flickr.


The world produces 300 million tonnes of plastic a year. There are 5 trillion pieces of plastic in the ocean, and 90% of seabirds have swallowed plastic.

The stats about ocean plastic are so stark and the problem so seemingly insurmountable, you could be forgiven for wondering what on Earth we're going to do about it.

But Dutch inventor Boyan Slat thinks he has a solution: a giant floating barrier, or boom, that uses natural forces to passively scoop up the waste. And it seems to be working in the Great Pacific Garbage Patch (GPGP).


Raft of ideas

After some false starts and six months of the barrier bobbing in the GPGP – an area between Hawaii and California about three times the size of France – the system has returned 60 bags of trash to the shore in Vancouver.

Everything from massive discarded fishing nets to microplastics 1 millimetre in size have been caught in the bags, which measure 1 cubic metre each.

Operated by Slat's environmental start-up The Ocean Cleanup, the system consists of a 600-metre-long barrier that sits on the surface of the water as well as a skirt that prevents debris from escaping underneath. The wind, waves and current push waste into the barrier, which is slowed down by an anchor so it moves at slower speeds than the trash.


Natural forces sweep trash into the system, which is slowed down by an anchor to allow it to trap the debris. © Ocean Cleanup.


A gyre purpose

The Ocean Cleanup says it could rid the GPGP of 50% of its waste in five years. Conventional methods of clearing the water, like vessels and nets, would take vast sums of money and thousands of years.

The area is the biggest ocean garbage patch on the planet, but it's just one of five around the world's major ocean gyres.

Like slow-moving whirlpools, gyres play an important role, circulating currents and redistributing the sun's energy around the globe. But they also suck in marine debris, turning vast areas of the ocean into plastic soup.


We're gonna need some robot boats

While The Ocean Cleanup's success so far might seem like a drop in the ocean (pun intended) compared to the scale of the problem, the organization says it has proven the concept works.

And the project has even more ambitious goals. In what it calls "the largest ocean clean-up in history," it wants to remove 90% of ocean plastic pollution by 2040.

It's also attempting to stop this pollution at its source: in the world's rivers. It has developed the "Interceptor," an autonomous, solar-powered catamaran that works in conjunction with a barrier to scoop plastic out of the water. Capable of extracting 50,000 kilogrammes of plastic a day, two of these craft are already at work, in Jakarta and Malaysia.

The Ocean Cleanup wants to send Interceptors to 1,000 rivers worldwide by 2025.



Boom or bust?

Whether these interventions are the answer to the world's growing ocean plastic problem remains to be seen. Some researchers claim that, as well as collecting trash, the boom design used in the GPGP could be hazardous to floating marine life.

The organization says it has not observed any entrapment of marine animals, and people will always be present to check the water while waste is being extracted.

Plastic is now so ubiquitous in the natural environment that scientists are suggesting our era will go down in history as the "Plastic Age."

But, with projects like The Ocean Cleanup working to find solutions, perhaps the plastic problem is not entirely insurmountable.



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Originally published in weforum.org.

Author: David Elliott.

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