Photo by Naja Bertolt Jensen on Unsplash
Remember the giant garbage patch in the middle of the ocean? Known officially as the Great Pacific Garbage Patch and nicknamed “the eighth continent," the patch gained international attention when, back in 1997, a boat captain named Charles Moore reported it took him seven days to pass through it.
An amazing and innovative device is helping clean up the garbage patch, but let’s back up and learn a bit about the garbage patch itself. Large systems of ocean currents known as gyres act like slow moving conveyer belts that circulate waters around the globe. Marine debris gets caught up in these currents and form giant whirlpools of floating garbage. There are five gyres in the planet’s oceans, but the most infamous one is the North Pacific Gyre because it contains the Great Pacific Garbage Patch (GPGP). The GPGP lies between California and Hawaii and is roughly twice the size of Texas or three times the size of France in area. Forty-six percent of the patch’s total mass is made up of derelict fishing nets, baskets, and cages. Waste from ships is also a huge contributor. But the worst and most offending constituents of the patch by far are microplastics – minute fragments of plastic eroded from larger pieces. Ninety-four percent of the patch is made up of 1.8 trillion pieces of microplastics less than 5mm in length (about the size of a fingernail). This makes the patch resemble more of a giant cloudy soup rather than what we may envision as a solid island of empty plastic bottles you could stand on. In fact, the patch’s density is so low that it is mostly invisible to the naked eye and even invisible to satellites.
Effect of the garbage patch on marine life
It’s bad enough when fish, birds, and other marine life get entangled in man-made debris or mistake plastic for food (remember the famous photos of albatross carcasses showing stomachs full of plastic pieces?), but when they ingest microplastics, chemicals in the plastic may absorb toxic chemicals that cause brain damage and behavioral disorders. Humans are also unknowingly eating plastic – and not just from eating affected seafood. Merely by eating, drinking, and breathing, the average American ingests 74,000 microplastic particles each year, according to the journal Environmental Science Technology.)
Dutch entrepreneur vows to clean up the Garbage Patch
In 2013, a non-profit organization based in the Netherlands called The Ocean Cleanup developed a 2,000-foot long U-shaped floating barrier that is not unlike containment booms used to contain oil spills. This device is pushed by wind, waves, and currents and skims litter from the ocean’s surface. Crewed boats tow the U-shaped barrier through water at 1.5 knots and a permeable screen catches subsurface debris. In 2015, the device was named one of Time magazine’s best inventions. Since then, prototypes have had various mechanical issues and undergone several design updates, but the goal has always been to extract pollution from the oceans, especially the Great Pacific Garbage Patch.
In October 2021, the organization’s latest design, known as System 002 or “Jenny,” gathered 62,000 lbs. of trash from the patch! See this short video or this more comprehensive one (go to the 2:00 mark to see the dramatic haul of plastic). This short video depicts the technology behind the device.
The long-term goal is to build sixty systems that will remove 50% of the Great Garbage Patch in five years. Another version of the device, called the Interceptor, is used to clean rivers, known as the main source of ocean pollution. The Interceptor is an automated, solar-powered system that captures and extracts waste before it reaches the ocean and then sends it to local waste management facilities.
What happens to the collected garbage?
Periodically, a support vessel removes the haul of plastic and transports it to land so it can be recycled into new products. Go here for a short "Trash Tour" of objects found in the patch with Boyan Slat, the founder and CEO of the Ocean Cleanup. He shows an odd sampling of objects collected in one haul that includes toilet seat covers, toothbrushes, sleds, scuba fins, and tons of fishing buoys and crates. He points out that objects have writing on them in many different languages and it’s clear they come from all over the world. According to Scientific American, researchers have found that the discarded plastic and debris come from six primary sources: China, Indonesia, the Philippines, Vietnam, Sri Lanka, and Thailand, -- more than all other countries combined. Scientists agree that China is responsible for 30% of worldwide plastic ocean pollution. You can play around with this "Plastic Tracker" to see the trajectory of litter as it makes its way around the globe.
Downsides of the device
The Ocean Cleanup has made some amazing strides, but it is not without criticism. Their device may not be robust enough to survive the open seas; should be closer to shore for easier maintenance; can imperil sea life, particularly organisms like jellyfish that live near the ocean’s surface; and does not capture plastics that are beyond the reach of gyres. Additionally, experts believe less than 5% of plastic pollution entering the ocean even makes its way into garbage patches where it could be collected, and microplastics are so small that they often escape the system altogether, eventually sinking to the bottom of the ocean.
British scientists from the Imperial College also feel it is more effective for plastic collectors like The Ocean Cleanup to prioritize clearing plastics around dense coastal economic and population centers (where there is a lot of marine life) before they can inflict more harm. Their view is that plastics that have travelled great distances (e.g. to the garbage patch) have already done about as much harm as they are going to do.
Why is it so hard to clean up garbage patches?
The size of the garbage patch is so immense that some calculations estimate it would take 67 ships one year to clean up less than one percent. Wikipedia says the patch is believed to have increased 10-fold each decade since 1945. The gyre actually contains around six pounds of plastic for every pound of plankton (a crucial source of food for aquatic organisms). Needless to say, the big solution to all this would be to stop manufacturing so much plastic. As global citizens, we can try to avoid buying items made of plastic and actively establish habits for saying no to plastic we don’t even use. (“Thanks, I don’t need the straw.”) Here is an article by Global Citizen on "Five Easy Ways You Can Avoid Microplastics in Your Life."
Sources:
https://www.iberdrola.com/environment/plastic-island-in-pacific-eighth-continent
https://www.cnet.com/news/plastic-is-ruining-the-oceans-but-there-are-ways-you-can-help/
https://en.wikipedia.org/wiki/Great_Pacific_garbage_patch
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