Your Digital Self: This is how the plastic that’s choking oceans can be cleaned up

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The world is being buried — or drowning — in plastic garbage.

It is estimated that about 3,330 tons of plastic waste is generated globally each year — nearly equivalent to the weight of the entire human population. Of that mass of plastic waste, 8.8 tons end up in world oceans each year. If we keep this up, the oceans might contain more plastic than fish by 2050, according to an estimate by the UN’s Ocean Conference.

So where did this plastic come from, where is it going, and what can we do to stop this worrying trend?

Source of pollution

A study published in Science concluded that the majority of plastic debris comes from six primary sources: China, Indonesia, the Philippines, Vietnam, Sri Lanka and Thailand. Of those, five countries excluding Sri Lanka dump more plastic trash in the sea than the rest of the world combined. Thirty percent of plastic ocean pollution comes from China.

At first, it seems the culprits have been caught. However, the truth is more complex: From 1992 to 2017, China was the largest importer of plastic waste, taking in a total of 45%. It was a mutually beneficial arrangement at first — low-cost Chinese labor was used to repurpose the plastic waste into products like sandals, phones and bottles, and rich Western countries such as the U.S. and the U.K. found it more profitable to sell their trash than recycle it on their own.

This arrangement lasted for 25 years, until the Chinese decided it was unsustainable. China stopped the imports, citing health and environmental problems. (To learn more about this topic, see the shocking documentary “Plastic China.”)

During that 25-year period, China imported 106 million metric tons of plastic. According to Statista, China is also the world’s largest plastic producer as of 2013, accounting for nearly one-fourth of global plastics production.

Most of the plastic trash currently floating in our oceans may come from China and the rest of the above mentioned Asian countries, but a substantial part of the debris is, in fact, recycled and reused plastic from the West. For example, despite the Chinese ban, the U.S. still manages to sell 81% of its waste to Asian buyers.

Thanks to the research published in Proceedings of the National Academy of Sciences, conducted in September of 2019, we now know that much of ocean plastic comes from Chinese cargo ships that throw their waste overboard, and not from land-based sources, as is often thought. The author of the paper argues that the “rapid growth in Asian debris, mainly from China, coupled with the recent manufacture of these items, indicates that ships are responsible for most of the bottles floating in the central South Atlantic Ocean, in contravention of International Convention for the Prevention of Pollution from Ships regulations.”

Enormous masses of ever-growing trash

Plastic waste can be divided into two distinct types: The first is plastic that originates from and around beaches and urban centers. This includes bottles, plastic bags, product packages and similar items that sink rather than being carried away by currents. The other group consists of items dumped by fishing boats and cargo-carrying vessels: fishing nets, barrels, ropes, plastic bottles and so on.

This other group of items is buoyant and susceptible to currents that form five major oceanic gyres. (A gyre is a system of circulating ocean currents.) Because of the circulatory nature of gyres, the plastic waste is not only carried by them, it is also accumulated (see visualization), forming the five great garbage patches of the world.

The most “popular” one is the Great Pacific garbage patch (GPGP), also known as Pacific trash vortex. Located in the North Pacific Ocean, halfway between California and Hawaii, it’s the largest offshore plastic accumulation zone in the world.

According to data acquired by Ocean Cleanup researchers, the patch covers 1.6 million square kilometers, which is two times the size of Texas and three times the size of France. While it’s easy to imagine it as a giant island of floating refuse, in reality it’s nothing like that.

Instead, GPGP is a widely dispersed area of microscopic particles concentrated in the upper water column. Its inner region contains 80,000 tonnes (88,100 tons) of plastic, which is equal to the weight of 500 jumbo jets. If its 1.8 trillion pieces of plastic particles were to be distributed, each human would get 250. According to the research results, GPGP isn’t static in size — in fact, since the 1970s, it has been growing exponentially. Mass-wise, most of the plastic in the patch (92%) is larger than 0.5 cm (0.2 in.), while in terms of object count, 94% is smaller than that, putting it in the microplastic category.

Why is plastic waste dangerous?

Plastic is a man-made material, most often derived from petrochemicals. It is designed to last. Most of it is not biodegradable, which means it cannot be decomposed by bacteria or other living organisms. Instead, it persists in the environment and, under the influence of the elements, is torn into smaller parts without changing its chemical makeup.

These small pellets, known as microplastics, are often swallowed by birds and fish, resulting in death by starvation (animals mistake fullness for satiety) or gastrointestinal complications. This is especially true for larger pieces of plastic (aka macroplastic) with which birds often feed their young.

Furthermore, many harmful chemicals are associated with plastics. These chemicals, many of which are toxic, carcinogenic or mutagenic, are released from the plastic as it fragments in the environment.

Finally, larger pieces of plastic can entrap animals, strangulate them or wrap around their necks or limbs, incapacitating them. Plastic waste kills up to a million seabirds, 100,000 sea mammals, marine turtles and countless fish each year.

Even worse, the circle doesn’t end at the sea. Plastic that enters the animal food chain eventually contaminates human food as well. As for economic implications, cleaning all this plastic mess is by no means a cheap business. The UN reports environmental damage caused by plastic in the marine ecosystem has reached $13 billion. As pollution increases, so does the price.

What’s being done to stop this?

There are many initiatives going on currently — some political, some engaging companies to change the way they produce, purchase and use single-use plastic goods (National Geographic is tracking these developments) — but the most interesting are those that actively seek to counter the pollution. Here are a few:

One of the most famous initiatives that aims to clean the oceans is The Ocean Cleanup — an NGO based in the Netherlands and run by Boyan Slat. The company has been developing technology to extract plastic pollutants from the ocean. The latest revision, introduced in October 2019, relies on natural forces to navigate garbage patches, following the same route as the plastics. Ocean Cleanup uses a water-borne parachute as a sea anchor, designed to slow the cleanup system and capture the plastics as it passes by it.

With successful implementation, Ocean Cleanup claims its system could erase 50% of the GPGP in only five years, and 90% of the ocean plastic after fleets of systems are deployed in all five gyres by 2040.

In 2016, a previously unknown type of bacteria was discovered in a sediment sample taken outside of a plastic bottle recycling plant in Sakai, Japan. To their amazement, Japanese researchers discovered that the bacteria, dubbed Ideonella sakaiensis, was able to dissolve PET plastics previously thought to be undegradable by secreting a special enzyme, PETase.

PETase chemically breaks down plastic into molecules that bacteria use for energy and growth, and the byproduct is carbon. Currently, however, it takes Ideonella sakaiensis a bit too long to chomp through plastic — it needs six weeks and ideal temperatures to eat through a film made of PET. A team of scientists from the National Renewable Energy Lab in Golden, Colo., is trying to speed up the process by improving the PETase enzyme. Their enzyme is 30% faster at working its way through PET than the one originally produced by Ideonella sakaiensis, but they’re hard at work on improving that result further.

Biologically breaking down PET is superior to what is currently being done with plastic, i.e. breaking it into smaller components without changing it chemically. Those components are then reused in lower-grade polymers for textiles or carpets. Byproducts released by breaking down PET chemically, however, yield components that are used in creating materials like Kevlar, which is two to three times more valuable than recycled PET plastic, and can be used for making bulletproof vests, racing sails and even bicycle tires. This would provide the economic incentive the recycling industry needs to increase its efforts and work more efficiently at getting rid of the global plastic pollution problem.

Finally, there is a company that takes a more mundane approach to solving the pollution problem. A U.S. for-profit company called 4ocean pledges to remove one pound of trash from the oceans for each product purchased in its online shop. It offers 100% cotton T-shirts, bracelets made of recycled plastic, educational books and more. With the money provided, the company invests in equipment and technology to stop the flow of plastic from land to oceans, as well as hire captains and cleanup crews that recover ocean plastic and harmful marine debris seven days a week.

It may take a while before all the plastic disappears from our oceans, but it is something the world is aware of, and it seems like real, honest effort is being put into this finally happening. Even though most of us are not directly engaged in these projects, we can at least do our best not to make the job harder. Here’s a handy list we all can use to start doing our part toward a cleaner planet.

Jurica Dujmovic is a MarketWatch columnist.

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