Tiny particles, bags, bottles: When plastic lands in the ocean, it harms wildlife and the environment. But how much plastic does end up there, and where does it come from? An overview of problems and solutions.
Every single piece of plastic that has ever been produced still exists today. It isn't in the same place anymore, and probably unrecognizable - but it's certainly still there, just no longer visible to most of us. As the global production of plastic increases, so does the amount of "invisible" plastic garbage somewhere in the world.
How much plastic do we produce and use?
Since its invention, the production of plastic has been growing almost exponentially. Today, 4 percent of the world's oil goes directly toward its production, with another 4 percent being used to supply the necessary energy to produce plastic.
That alone makes plastic a material that isn't particularly environmentally friendly. Furthermore, a lot of plastic is used to make disposable products rather than lasting ones.
Today, plastic products in all shapes and sizes exist throughout the world. But while the average human uses 45 kilograms (99 pounds) of plastic per year, there are vast differences among the different geographic regions.
With a share of 26 percent, China may be the largest plastic producer in the world - yet the largest plastic consumer is neighboring Japan. The people living in the island nation have a consumption that exceeds even that of the entire rest of Asia and Africa combined.
What happens to plastic waste?
Depending on the country, a little more than 22 to 43 percent of plastic waste ends up in landfills.
How much plastic trash a country recycles on average is not recorded in a standardized manner throughout the world. In defense of big plastic consumer Japan, it has to be said that its recycling rate of 77 percent is among the highest in the world. Many countries don't even get close: the European Union, which is often a pioneer when it comes to environmental issues, only recycles 26 percent of its plastic trash.
However, there is recycling - and then there is recycling. The EU, for example, exports half of its plastic recycling trash abroad, most of to China. Nobody knows what happens to it there. According to a report by the International Solid Waste Association, there is no reliable information about what happens to the imported material once it has reached China.
One thing is clear, however: not all plastic trash stays on land. A portion of it ends up in the ocean, where it causes damages amounting to at least $13 billion (about 12.3 billion euros) per year.
A little less than half of the plastic garbage in the ocean originates in the coastal regions of just five countries: China, Indonesia, the Philippines, Vietnam and Sri Lanka.
Where in the ocean does the plastic end up, and what impact does it have?
Plastic particles can be found at the surface, in the depths, in the sediment and in the water of the ocean - anywhere between the South Pacific and the drift ice of the Arctic.
Regardless of where in the ocean plastic is, one thing is certain: The amount is too large, and most particles too small, to be able to collect it all.
Which makes one question all the more pressing: What impact does the plastic have where it is? After all, the plastic runs into various life forms at every ocean depth. A study conducted in 2014 showed that 267 different species had either ingested plastic or gotten entangled in it.
Some plastic products are very light and therefore float at the surface but most plastic products have a higher density than sea water and sink down to the ground. The life expectancy of the products is an estimate since no empirical data is available yet
Plastic has long since become an inherent part of the oceans. An estimated 5 trillion plastic particles are floating at the ocean's surface. The large majority of them are so-called microplastic particles - particles that are smaller than 5 millimeters in diameter.
Half of them gather in five garbage patches throughout the world. They don't consist only of a layer of trash that floats at the surface, but are rather like soup containing many mostly very small particles.
These garbage patches are vortexes that are connected to one another. As a result, practically any piece of plastic makes a trip around the world sooner or later. How long this world tour takes depends on where and when the piece reaches the ocean and how heavy it is. On the website Adrift, you can throw a virtual rubber duck into the ocean and have the site generate a simulation of its most likely path.
On its real-world travels, microplatic encounters plankton, among other things - an encounter with far-reaching consequences because this is where the plastic enters the food chain. Fish eat it, whales and clams absorb it as they filter large amounts of water. That way, it comes back to us in the form of grilled herring or steamed mussels. And the health impacts of that are not yet clear.
Plastic doesn't just end up on our plates, but also on beaches. Seven of the 10 most common objects that the volunteers of the Ocean Conservancy collected on beaches worldwide in 2015 were made of plastic. Among them: plastic bottles, food packaging, bottle caps, drinking straws and plastic bags.
Even in the deep sea - one of the most inhospitable places in the world - scientists have found plastic bottles that were almost completely intact. Because there is no sunlight there and the oxygen level is lower, plastic biodegrades particularly slowly here. On some expeditions, researchers found samples that had been produced during the 1960s.
As plastic breaks down, it doesn't simply disappear - no matter how long the process takes. At some point, tiny microplastic particles take on their own life. On such particles sampled from the Mediterranean, researchers found microscopic organisms like paramecia, algae, bacteria and fungi. These cover the entire surface of the small particles, turn them into their own tiny ecosystems.
So the plastic particles never travel alone. Instead, they become a means of transport for tiny species all around the world.
What are the possible solutions?
But there are some rays of hope from nature: In the miniature ecosystems on the microplastic particles, biologists have discovered a film of bacteria that covers the surface of the plastic. In the lab, they discovered that these bacteria can break down the plastic completely - thus accomplishing something the elements themselves cannot.
Although this may sound like a silver bullet in the fight against plastic garbage in the ocean, scientists are quick to dampen such illusions: the amount of unwanted waste plastic is simply too big for the bacteria to eliminate it on their own.
A second approach is to produce plastic in a different way to make it biodegradable. Experts criticize that this has been largely a marketing strategy. Bio-plastic only degrades at 50 degrees Celsius (122 degrees Fahrenheit) - not an easy temperature to find in nature. At the same time, bio-plastics are heavier than conventional plastic, and would therefore sink below surface. As a result, it would be exposed to less ultraviolet radiation, which could accelerate the degradation process.
The third idea is to recycle more - and to establish binding standards for plastics recycling. However, even today there are no standardized and global surveys of which country produces how much plastic, what percentage gets recycled (including how exactly "recycling" is defined), how much ends up in landfills, and how much in the oceans. It wasn't until 2009 that the United Nations Environment Programme presented guidelines for evaluation and data surveys related to this issue.
Scientists believe it is high time that recycling rates improve. If nothing changes by 2025, the amount of plastic that reaches the ocean every year will grow tenfold, increasing to more than 80 million tons.
Environmental organizations have already demonstrated the great potential of recycling: Five recycled PET bottles can provide enough fibres to make a T-shirt.
Recycling 100 million mobile phones saves enough energy to power almost 200,000 homes in the United States for one year.
Old plastic cups can get a second life as garbage cans, park benches, playgrounds, or kayaks. But the idea with the most potential is very simple: Use less. Understandably, that's not a very popular concept in the plastics industry, which generates revenues of $600 billion per year. Which, many believe, is why government action to ban plastic bags and disposable cutlery is all the more important.
If a small country like São Tomé & Príncipe gives up plastic, this only slows down the global plastic bag counter slightly - although every bit helps.
And if a whole country can do it, then maybe so can you?
Please also have a look on this picture gallery from June 8, 2016.