This plastic water bottle is  about to go on an adventure.

Not to a landfill, although  hundreds of billions like it certainly end up there every year. And not to a recycling plant, which would be better.

No, this bottle gets caught in a gust of wind and makes its way to a nearby river. From there, it’s off to see the world! It has a ticket to the  Pacific Ocean, and eventually, the 1.6 million-square-kilometer Great Pacific Garbage Patch.

And unfortunately for all of us, the adventure doesn’t end there. It’s going to break into tiny  pieces and wind up in places even the most seasoned travelers rarely go. Are your bags packed?

Because we’re going to tag along with this plastic bottle on its entire trip. We’ll see the bottom of the  ocean and the North Pole! We can't promise it will be pretty, but understanding this journey is the first step in stopping other plastics from taking the same disturbing path. [SciShow Intro Music] This episode was made in  partnership with Wild Hope.

Wild Hope is a series of short, free documentaries right here on YouTube that bring you stories about scientists and changemakers who are restoring our wild  places and sparking new hope for the future of our planet’s biodiversity. Worldwide, as many as 34 billion plastic bottles end up in the ocean each year. That’s four bottles for every person on Earth.

Most of them come from countries that have a lot of coastline like the U. S. So our water bottle has plenty of company as it floats down a river in the American West and into the North Pacific.

Rivers are one of the main ways that plastic gets from the land to the sea. As much as 2.7 million tons of plastic makes this trip every year. And once our bottle plastic does reach the sea, ocean currents take it for quite a ride.

The Earth’s prevailing winds, together with the force from  the rotation of the planet, create a number of large circular currents called gyres. These pull floating plastics  towards their centers. In the North Pacific, this creates the infamous  Great Pacific Garbage Patch.

Our water bottle’s journey can take a few years, but once it reaches the patch, it joins as many as 3.6 trillion  other pieces of plastic. Everything from fishing equipment to buckets and crates to other food and drink packages. And despite that being an unbelievably big number, there is weirdly less plastic floating on the surface of the ocean than scientists expect there to be.

We’ve been churning out plastics since the 1950s, yet less than 1% of the plastic that has ever entered the ocean is floating on the surface today. So where did the other 99% go? The vast majority of it  appears to sink and degrade.

Take our bottle, for example. The only reason it’s still bobbing along on the surface is that it still has its cap. That cap is made of a durable plastic called high-density polyethylene or HDPE.

This will float on its own and will stick around the garbage patch for a long time. But the bottle itself is made  of polyethylene terephthalate, or PET. This is a lot less durable and crucially, it doesn’t float very well.

So once the cap separates, the two part ways forever as the bottle takes on a little water and sinks down into the abyss. We’ll get to its fate in a minute. But back on the surface, the cap keeps bobbing away.

While plastic takes an incredibly long time to completely decompose, it does fragment and break apart. And out in the open ocean, there are a ton of forces  helping that process along. UV radiation and oxidation slowly degrade the chemical bonds holding the plastic together, which makes it easier for wind, waves, and grinding against other trash to break it up into smaller pieces.

This is how macroplastics  gradually turn into microplastics, pieces that are less than 5 millimeters. And that’s a big part of how 99% of the plastic that has ever entered the  ocean can seemingly vanish. They’re not gone forever.

The plastics just get too small to see with the naked eye. Microplastics are very hard to track, but thanks to the diligent work of scientists, we’ve begun to figure out that they go … everywhere. Seriously, it would almost be easier to list the places we haven’t found microplastics.

So our story of a single plastic water bottle now splits into the stories of thousands of microplastic pieces spreading out throughout the world’s oceans. One small floating piece gets gobbled up by a hungry albatross. Other bits are eaten by fish and sea turtles.

As you might expect, these pieces aren’t great for the animals’ digestive systems. Seabirds are especially vulnerable because they don’t tend to regurgitate things they can’t digest. Ingested plastic makes animals feel more full and eat less.

A 1995 study found the more  plastic birds ingested, the less they weighed. And a 2023 study documented  a new disease in seabirds called plasticosis. This is when plastic pieces damage and scar the inside of a bird’s digestive system.

As the remaining bits of the cap break up into smaller and smaller pieces, algae and plankton build up on them, weighing them down and causing them to sink. In surveys, scientists have observed  more little pieces of plastic below garbage patches than elsewhere in the oceans. They refer to this plastic fallout.

Eventually many of these join the rest of the bottle on the seafloor. Researchers estimate that the plastic sitting on the ocean floor could weigh as much as 11 million metric tons. That’s at least 10 times as much plastic as is floating on the surface.

PET, which our bottle is made of, is thought to stay relatively intact for around 15 years in the ocean. But it too will fragment eventually. Invertebrates living on the seafloor like worms or sea cucumbers can ingest those microplastic fragments, contaminating a deep sea ecosystem we still barely understand.

Some pieces of our bottle end  up traveling even farther. They get caught by ocean  currents flowing northwards and make it all the way to the Arctic. There they freeze into sea ice, only to be released back out and continue the journey a few years later.

A gray whale swallows another  microplastic fragment, but it doesn’t stay put in  the whale’s digestive tract. A 2023 study found that microplastics can migrate between cells or  through a whale’s circulatory system and end up lodged in its blubber. And microplastics can be toxic.

The plastic itself can include toxins, but we also need to worry about everything that piece of plastic picked  up on its long journey. Smaller plastic pieces have  comparatively more surface area than bigger ones. And most plastics are hydrophobic, meaning they repel water.

But that surface can attract  other hydrophobic substances. This includes toxic chemicals like PCBs. So microplastics act as little  collectors of these chemicals.

This means PCBs can be  concentrated a million times more on microplastics than in the surrounding water. When animals ingest microplastics, they get a huge dose of all these chemicals. And yes, animals include us humans.

A final microplastic fragment from our bottle washes towards shore where it flows through a shellfish farm. It gets ingested by an oyster, which is eventually harvested, shucked, and slurped down by an enthusiastic foodie. Fish, shellfish, and drinking water are the main ways that microplastics end up in us.

They’ve been found in human lungs, blood, intestines, and more. Most of what we know about  the effects of microplastics on our health comes from laboratory experiments. These have shown microplastics can be toxic to cells and cause DNA damage.

Experiments on human organoids, which are lab-grown tissue samples, have shown potential toxic effects to airways, intestines, the liver, and brain. We’re just beginning to see results from the first studies looking at microplastics in actual living humans. A 2024 study found that people who had microplastics in their arteries had a higher chance of stroke, heart attack, and death.

Now I know this sounds like a lot of gloom and doom. But we are making progress on stopping plastic from making this journey. And at every step of our water bottle’s trip, there are people working on ways to give this story a happier ending.

It all starts with waste management. That means making sure  bottles either get recycled, or disposed of in a sealed landfill so they don’t escape into the environment in the first place. And we kinda have to say this every time, but the best solution to plastic waste is to create less of it to begin with.

What if we just replaced 1 in  10 plastic bottle purchases in coastal countries with a refillable bottle? Even that small fraction could prevent as many as 7.6 billion plastic bottles every year from going on a similar journey as ours did. Still, we need to tackle the problems that we’re facing today.

That means doing our best to  clean up the mess we’ve created. And there are promising  efforts to clean up the plasti c that does slip through the cracks. Since the width of rivers is a lot smaller than the  vast expanse of the ocean, it would have been a lot  easier to catch our bottle when it was still in the river.

People have tried everything from floating booms, to cleanup boats, to simply collecting plastics  by hand along the shoreline. These have had a lot of success. In the early 2020s, an organization called The Ocean Cleanup deployed floating barriers across drainage gullies in Jamaica, Guatemala, and elsewhere.

These catch and hold floating plastics until they can be scooped up by a small barge. In Baltimore, two trash wheels have scooped 750,000 plastic bottles like ours out of the harbor so far. And even once our bottle made it to the Great Pacific Garbage Patch, it wasn’t beyond reach.

The Ocean Cleanup has designed a net specifically for this purpose that can be towed between two ships to capture floating plastic. They’ve demonstrated that we can clean up ocean  garbage patches directly. But that doesn’t mean it’s going to be easy.

A 2019 study estimated that achieving a significant reduction worldwide would require nearly 2,000 more  Ocean Cleanup sized projects. There’s no easy way to rid  the planet of microplastics. But cleaning up rivers, beaches, and even the Great Pacific Garbage Patch represents an opportunity.

This is a chance for us to  rescue all of that plastic before it fragments into microplastics, slips through our grasp, and ends up in the worst possible places. This video was inspired by  the episode from Wild

Hope: The Great Ocean Cleanup. Watch that episode now, and many more from Wild Hope, right here on YouTube – or follow @wildhopetv on Instagram to discover countless more stories of changemakers working to restore biodiversity around the globe. Change is closer than you think. [ OUTRO MUSIC ]