A young Dutch engineer named Boyan Slat is currently conducting a feasibility study for a device that could help clean up our oceans. The device, dubbed The Ocean Cleanup Array, would consist of a series of floating booms and 24 manta ray-styled processing platforms that could collect and filter floating debris. The processing platforms would be anchored to the ocean floor, letting the sea’s currents direct the debris into the booms and eventually through the processing platform.
While estimates vary, it is widely agreed that there are some tens of billions of kilograms of garbage in our oceans. Most of the ocean’s pollution comes from land, travelling through rivers and waterways, then washing out to sea. This pollution gets caught up in ocean currents, with the majority of it accumulating in five areas of the oceans: North Pacific, South Pacific, North Atlantic, South Atlantic, and in the Indian Ocean. These are called gyres, systems of rotating ocean currents that act like slow moving whirlpools, gathering up debris on the water’s surface and pulling it toward their centers. Most of the debris located in gyres will take decades to break down, and some of it has been there for decades already.
The gyre in the North Pacific is the largest, being roughly the same size as Texas, and has been called the “Great Pacific garbage patch” or the “trash vortex.” It is estimated that there are six kilograms of plastic for every kilogram of natural plankton in this patch. While visible debris ranges from bottles and plastic bags to large fishing nets and buoys, there is also a multitude of microscopic debris from broken-down plastics. According to the Save Our Seas Foundation, 60-80% of marine debris is plastic, with concentrations of 90-95% in some areas.
The pollution in our oceans kills hundreds of thousands of aquatic animals and birds annually, as animals either consume the plastic products or get tangled up in the debris. Consumption of the plastics can harm other animals indirectly, including humans, as pollutants like PCB and DDT accumulate in animals’ bodies and move up the food chain. If successfully implemented, it is predicted the Ocean Cleanup Array could clean up a third of the ocean’s surface plastic pollution in five years’ time.
Slat started The Ocean Cleanup Foundation in January 2013 to fund the development of the Ocean Cleanup Array. They are now working with a large team of experts to conduct a comprehensive feasibility study in the fields of engineering, oceanography, economics, recycling and maritime law. The Ocean Cleanup Array would consist of 24 processing platforms, along with a series of booms, and be located across the radius of each of the world’s five ocean gyres. The processing platforms would be anchored to the ocean floor and would operate on a combination of solar and hydroelectric power. The design of the processing platforms is similar to that of a manta ray, with flexible, wing-like areas being connected to the booms in order to ensure sustained contact with the surface of the ocean. The floating booms would act as giant funnels, using the force of the surface current to direct the debris toward the processing platform. Once the debris entered the platform it would be filtered out from the water, then stored in containers until it could be collected, taken ashore and recycled.
The floating booms are expected to result in virtually no by-catch; they do not have any netting, and the current washes the debris toward the processing platform at such a slow speed that marine life could easily escape. The Ocean Cleanup Array would not interfere with shipping traffic either, as most would be installed in areas that are rarely travelled. Where necessary, the system would be set up parallel to existing shipping routes and contain a series of gaps throughout the array.
It’s not clear how much the project will cost, however the Ocean Cleanup team believes that it would be profitable. The Ocean Cleanup Foundation is currently completing their feasibility study with the help of PayPal donations, but if the project were implemented then the sale of the plastic retrieved from the five gyres is expected to generate roughly 500 million US dollars. The Ocean Cleanup Foundation expects to publish the results of their feasibility study in May of this year.