By S. Mathur
Everyone has heard of the Great Pacific Garbage Patch and the damage caused to marine life by plastic pollution in the oceans. The good news is that The Ocean Cleanup, a project envisioned in 2012 by a Dutch teenager, has finally started operations and hauled in its first 60 bags of trash, captured by a floating U-shaped barrier in the Pacific Ocean. The project has faced and overcome several design challenges, such as ensuring that the floating device captures trash without trapping sea creatures as well. The plan is to find a way to recycle the recovered plastics so that the project begins to pay for itself.
While cleaning up plastic pollution in the oceans will take multiple strategies, including reducing plastic usage and preventing the garbage from reaching the ocean, The Ocean Cleanup’s project is driven by the urgent need to reduce the size of the massive garbage patches that are actively harming sea life. Unlike earlier efforts to remove the garbage, which relied on mechanical collection using nets that trapped fish and dolphins, The Ocean Cleanup uses the ocean currents to sweep the garbage into the nets which hold it until it can be collected by a pick-up vessel. The next stage is to deploy interceptors at or near river mouths to capture garbage before it can reach the oceans. The Ocean Cleanup already has two Interceptors in operation and many more planned.
The garbage patches and the Ocean Cleanup
The Great Pacific Garbage Patch, is one of the five major floating conglomerations of garbage in the world’s oceans. They are made up of garbage that has been washed into the oceans from rivers and carried by the currents to form the five patches, two each in the Atlantic and Pacific Oceans and one in the Indian Ocean. The Great Pacific Garbage Patch, estimated to be twice the size of Texas, is located between Hawaii and California. For a long time, the experts believed that cleaning up the gyres was impossible: it would take too long and be too costly as well as energy-intensive.
Earlier efforts relied on vessels using nets to pick up garbage, and were in fact too inefficient as well as harmful in terms of by-catch. The nets were also limited in their ability to pick up microplastics, which are formed by larger pieces breaking down in the water. The Ocean Cleanup is the brainchild of a young Dutch inventor, Boyan Slat, who began, at the age of 19, to work out a way of cleaning up the floating plastic in the oceans without harming fish and other sea creatures in the process.
Slat came up with the idea of passively collecting garbage using a floating boom that would rely on the ocean currents instead of fossil fuels to power the system . The current U-shaped boom is the latest design which allows fish and other sea animals to swim underneath, while it captures floating plastic debris ranging in size from microplastics to discarded tires. The floating device also picks ‘ghost nets’, drifting pieces of fishing equipment that entangle and endanger sea life. Each year around 600,000 to 800,000 metric tonnes of fishing gear is dumped or lost at sea.
System 001/B is now operational
After many trials and setbacks, the current model, System 001/B, was finally put into operation last year. The design of the autonomous garbage collecting system is simple and effective. A floating U-shaped boom moves slowly through the water following the ocean currents, passively collecting garbage as it goes. A sea anchor creates a drag so that it moves slower than the floating garbage. This enables the system to concentrate and then collect garbage. A 10-foot net under the boom keeps plastic from escaping underneath, but fish and other creatures can swim under it.
System 001/B is fitted with sensors and transmitters so its position can be tracked as it floats through the Pacific picking up garbage. The sensors also alert a pick-up vessel when the system is full and the garbage collected needs to be brought ashore. The next stage of the project involves the recovered plastics,. They will be recycled and turned into premium products. The Ocean Cleanup is also ready to scale up System 001/B, but needs more financial backing. Models estimate that a fully scaled-up system could clean up as much as 50% of the Great Pacific Garbage Patch in just five short years. And by 2040, it could remove as much as 90% of existing ocean plastic.
Next up, the Interceptor
The next stage in cleaning up ocean pollution is to prevent garbage from washing down rivers into the sea. The Ocean Cleanup already has two Interceptors deployed on rivers in Indonesia and Malaysia, and has plans for more. Their research pinpointed the thousand most polluting rivers in the world, that are responsible for about 80% of the garbage that washes into into the sea. The goal is to have Interceptors installed at all of these within the next five years.
As the name suggests, the Interceptor collects garbage from the river water flowing through it. It works autonomously, using a conveyor belt to distribute the garbage among dumpsters lined up inside. Its solar-powered onboard computer is connected via the internet, and notifies a collection vessel when the dumpsters are full. Perhaps most importantly, it is scalable and can be used in rivers anywhere in the world. Similar devices are in use elsewhere, like water wheel in Baltimore harbor that has been collecting garbage since 2014, though they lack the scalability of the Interceptor.
A complete solution to the problem of plastic pollution would of course require turning off the tap by way of a drastic reduction in the production and use of plastics, as well as the development of biodegradable alternatives. But for tackling the problem cleaning up the legacy plastic that is choking the seas, The Ocean Cleanup is an inspiring start.