05/11/2018 – Sustainability series / Plastics, Ocean / Clean-up
Tackling ocean waste: ‘Pac Man’ and the great Pacific clean-up
After years of conducting reconnaissance expeditions, scale model tests and the deployment of prototypes on the North Sea, the world’s first full-scale marine plastic clean-up system – emulating the action of ‘80s video game icon Pac Man – has just been deployed in the so-called ‘Great Pacific Garbage Patch’ to gobble up one of the world’s most unwieldy manifestations of manmade waste.
Located halfway between Hawaii and California, the Great Pacific Garbage Patch is the largest accumulation zone for ocean plastics on Earth. Covering an area approximately twice the size of Texas, the Patch took shape in the gyre of the North Pacific Subtropical Convergence Zone, where the prevailing currents create relatively stable waters that make it perfect for plastic bottles, bags, six-pack beer rings and fishing gear to clump together en masse. Rivers play a particularly important role in transporting such mismanaged plastic waste from land into the ocean – and remarkably, just 20 are responsible for two-thirds of the global plastic input. The result of such contributions is truly startling. Analysis from earlier this year revealed that the Great Pacific Garbage Patch contains as much as 16 times more plastic than previously estimated, with around 1.8 trillion pieces of plastic weighing 80,000 metric tons currently afloat in the region – and the situation is rapidly getting worse.
Enter ‘The Ocean Cleanup’. On 8th September, the Dutch non-profit organisation launched the world’s first ocean clean-up system from San Francisco Bay with the aim of ridding the Pacific Ocean of the humungous floating plastic island – a permanent, sprawling by-product of 21st century consumerism.
Attack the Patch
Towed from the Bay by vessel Maersk Launcher, the so-called ‘System 001’ headed to a location 240 nautical miles offshore for a two-week trial before continuing its journey toward the Great Pacific Garbage Patch, 1,200
nautical miles offshore, to start the clean-up operation.
Hundreds of scale-model tests, a series of prototypes, research expeditions and multiple iterations have led to The Ocean Cleanup having sufficient confidence in its technology to launch its first full-scale clean-up system. System 001 consists of a 600-metre-long U-shaped floating barrier with a three-metre skirt attached below. The system is designed to be propelled by wind and waves, allowing it to passively catch and concentrate plastic debris in front of it. Due to its shape, the debris will be funnelled to the centre of the system. Moving slightly faster than the plastic, the system will act like a giant Pac-Man, skimming the surface of the ocean.
Return to sender
System 001 will be deployed in the Great Pacific Garbage Patch, the world’s largest accumulation zone of ocean plastics, and The Ocean Cleanup anticipates that the first plastic will be collected and returned to land within six months after deployment. This will mark the first time that free-floating plastic will have been successfully collected at sea. After returning the plastic to land, The Ocean Cleanup plans to recycle the material into products and use the proceeds to help fund the clean-up operations.
While the main objective of System 001 is to prove the technology and start the clean-up, a secondary goal is to collect performance data to improve the design for future deployments. As a result, the system is equipped with solar-powered and satellite-connected sensors, cameras and navigation lights to communicate the position of System 001 to passing marine traffic, and enable extensive monitoring (of both the system and the environment). After delivery of the system to the Great Pacific Garbage Patch, the Maersk Launcher – whose assistance has been offered to the project by shipping giant AP Moller–Maersk – is set to remain active as an observation platform for several weeks thereafter.
Ready to float
The size of the task faced by The Ocean Cleanup cannot be overstated – nor can the scope of the hazard that the Great Pacific Garbage Patch poses to sea life and the wider environment as the pollution persists. Surface waters of the Great Pacific Garbage Patch contain 180 times more plastic than marine life by weight, according to an international team of scientists from The Ocean Cleanup and six universities from five countries. And a study in the journal Environmental Science and Technology reports that plastics floating in such oceanic accumulation zones carry chemical pollutants whose levels seem high enough to pose a health risk to organisms that ingest them.
While the presence of pollutants on ocean plastics is well known, the environmental chemistry and toxicological hazard of those substances remain poorly understood. Yet clearly, the sheer quantity of plastic encountered by sea surface feeders in the GPGP should be of concern. So too should the persistence of such material in nature cause alarm. A good example of this was collected from a research expedition to the Patch last year, when The Ocean Cleanup team recovered an almost perfectly intact plastic crate bobbing on the sea surface – its date of production was 1977. Remarkably, durable plastic items such as that – alongside PET bottles, disposable nappies and beer holders – can actually take up to 450 years to fully biodegrade.
The fact that the individual behind arguably the biggest solution to date to this gargantuan problem established his non-profit organisation at the tender age of just 18 is no less remarkable. “I am incredibly grateful for the tremendous amount of support we have received over the past few years from people around the world, which has allowed us to develop, test, and launch a system with the potential to begin to mitigate this ecological disaster,” enthuses Boyan Slat, the Dutch-born founder and CEO of The Ocean Cleanup, who set up the organisation five years ago in his hometown of Delft. “This makes me confident that, if we manage to make the technology work, the clean-up will happen.”
Mr Slat says the recent launch of System 001 represents “an important milestone” for the project, although notes that the real celebration will come once the first plastic returns to shore. “For 60 years, mankind has been putting plastic into the oceans; from that day onwards, we’ll be taking it back out again.”
Once successful, and assuming that funding becomes available, The Ocean Cleanup aims to scale up to a fleet of approximately 60 systems focused on the Great Pacific Garbage Patch over the next two years. Impressively, the firm projects that the full fleet could remove half of the plastic in the Great Pacific Garbage Patch within five years’ time. After full-scale deployment in the GPGP – also known as the North Pacific gyre – the firm intends on gradually expanding to the planet’s other four gyres: in the Indian Ocean, North Atlantic, South Atlantic and South Pacific. Such lofty aims are in line with The Ocean Cleanup’s ultimate goal: reducing the amount of plastic in the world’s oceans by at least 90 per cent by 2040.