Narrator: In 2012,
a teenager came up with an ambitious plan
to eliminate plastic in the ocean.
Boyan Slat wanted to harness natural currents
to collect floating debris inside a giant U-shaped barrier.
I believe the Great Pacific Garbage Patch
can completely clean itself
in just five years.
Narrator: That timeline didn't work out,
and there's still a garbage truck's worth of plastic
entering the ocean every minute on average.
But The Ocean Cleanup has made progress.
The nonprofit has removed more than 200 metric tons
of trash from the Pacific.
Many people said that it couldn't be done,
that it was a fool's errand, a pipe dream.
Narrator: But to really make a dent in plastic pollution,
the organization's going closer to the source.
Most ocean plastic comes from rivers,
so the Dutch entrepreneur invented these big machines
that capture waste before it ever makes it to open waters.
Rivers are the arteries
that carry the trash from land to sea.
Narrator: They're called Interceptors,
and the founder plans to deploy 1,000 of them.
But some experts worry
these machines could strip rivers and oceans
of things that are supposed to be there, too.
So can a network of trash barriers
clean the world's most polluted rivers?
And are cleaner rivers the key to a plastic-free ocean?
The Rio Ozama in the Dominican Republic
flows into the Caribbean Sea.
It's one of the dirtiest rivers in the world,
and Carmen Encarnacion has lived nearby for 24 years.
Narrator: The Ocean Cleanup installed an Interceptor
about a mile down the river from her home in 2020.
Narrator: The idea is to let the current
do most of the work.
As trash travels downstream,
this 700-foot-long arm redirects it
toward the machine's opening.
Boyan: So what the barriers do is they let the water pass,
but they stop everything that's floating.
On the roof, we have these solar panels
that are connected to batteries, which store the energy,
so that even at night we can keep intercepting plastic.
Narrator: Conveyor belts carry the waste
to one of six dumpsters.
They can fill up in just three days during the rainy season.
A lot of today's haul is plants.
And in this case, that's probably not a bad thing.
These are invasive water hyacinths.
They grow naturally in the Amazon,
but over the past century,
humans have introduced them to new places
where they don't have any predators,
like the Ozama River, where they're taking over,
blocking light and oxygen
and killing plants and animals beneath them.
The plant tends to thrive in polluted water,
and its roots cling to trash.
Narrator: Nearby factories and farms have used this river
as a dumping ground for decades.
But in Santo Domingo,
many people who live on the Ozama's banks
depend on it for drinking water.
A lot of them also have limited options
for dealing with waste.
Erik: It has to do with urban planning,
and these communities here
don't have the access roads for the trucks to come in.
Narrator: So some locals dump their trash
and drainage ditches called cañadas.
So right behind me, we have the Cañada Bonavides.
It's one of the worst cañadas
we have here in the Ozama River.
Just like the rivers are the arteries
that take the plastic to the ocean,
these cañadas here are the arteries
that take the plastic to the river.
Narrator: The Ocean Cleanup estimates the Ozama carries
up to 22,000 metric tons of plastic
into the Caribbean Sea each year.
The nonprofit has 10 other Interceptors
in rivers around the globe.
The devices can't remove all types of pollution,
like chemicals, or plastic that doesn't float.
And until residents have more options
for dealing with trash,
it'll keep ending up in the Ozama.
Erik: We rely heavily on working with local partners,
such as the Dominican navy here, or the UNDP,
precisely to work on this upstream problem.
Narrator: The Navy handles day-to-day operations
for the river cleaner,
and it works with the national government
to manually collect trash that slips by the Interceptor.
Erik: They have proven to be the perfect partners for us,
and by the end of the year,
they should be owning the Interceptor.
Narrator: Once that happens,
The Ocean Cleanup will shift its focus to other rivers,
like the Rio Motagua in Guatemala,
which the nonprofit says might have more plastic
than any other in the world.
Boyan: In Guatemala,
there's so much trash coming down the river
that these machines would be filled within a few seconds.
So there, again, we have a different type of Interceptor.
Narrator: The nonprofit built an Interceptor fence
to catch plastic in a flash-flood zone
that flows into the river.
Boyan: Every river is unique.
You really need to adapt it
to the specific circumstances of that river.
Narrator: The fence lets some plastics through,
but Boyan expects to have an updated Interceptor
by the end of 2023.
Meanwhile, the founder hasn't given up on his initial dream:
cleaning the Great Pacific Garbage Patch.
He founded The Ocean Cleanup in 2013,
and a decade later, the patch is still growing.
One challenge is that it isn't really a patch.
It's actually two swirling clouds of debris,
which often aren't visible on the surface.
Natural currents have created
five whirlpools like it around the world, called gyres,
and each one collects trash.
The nonprofit is working on cleaning up
the North Pacific Gyre using this thing.
It's a flexible barrier stretched between two ships
with a shallow screen hanging off.
The idea is to consolidate floating plastic,
making it easier to collect about once a week.
The Ocean Cleanup says in total,
it's removed more than 200 metric tons of plastic
from the Pacific Gyre.
Yet, it's only about two-tenths of a percent
of all the plastic that might be floating here.
The team is working on a system
three times bigger than this one,
which should be ready sometime in 2023.
Some researchers worry
these cleaning machines can disrupt ecosystems
by scooping up living things along with trash.
The Ocean Cleanup says the screen creates a downward flow
that carries living creatures under it.
But the system still catches some fish,
crabs, barnacles, and other animals.
The nonprofit says it's continually fine-tuning the device
to try to keep creatures out,
but it's impossible to avoid them completely.
That's partially because sea life
is all mixed up with the plastic
and can even live right on it.
Martin: Sea urchins,
sea stars,
pretty much anything that you can imagine,
you can also find on these plastic flows.
There's a lot of organisms that also attach their eggs
to these floating plastics.
Narrator: Some critics say the whole idea
of passively harvesting plastic is risky.
Martin: Once it is in the ocean,
it is connected
with marine life.
It's too late to remove it.
Narrator: A potential alternative
is targeting clusters of trash
instead of sweeping the whole gyre.
Plastic in the open ocean tends to form
these plastic dust bunnies at sea.
Collecting the plastic debris is also pretty easy
once it's clumped into these dust bunnies,
because then you have a single targeted area
with an extremely high amount of plastic.
Narrator: Those clumps are mostly fishing gear,
which does the most damage.
Rebecca: By focusing on things like ghost gear,
which are really, really dangerous to marine life,
you're collecting the most harmful plastic out of the ocean,
not necessarily collecting
some of the less harmful plastic things,
like laundry baskets or buckets,
which may have a lot of life growing on them.
Narrator: The Ocean Cleanup says that in the long run,
its ocean systems will be more scalable
than manual cleaning.
When it comes to its river cleanup,
experts were more optimistic.
I loved it, and the diagrams,
how it sort of funnels it in.
I was like, that is so perfect.
Once it's in the ocean, it's a problem
that really becomes much harder to manage.
Narrator: That tracks with Boyan's results.
As of April 2023, his team has collected more than 10 times
as much plastic from rivers as from the ocean.
In Santo Domingo,
members of the Dominican navy empty the dumpsters
and send the haul to the Duquesa landfill.
Boyan: Of course, landfill's not ideal,
but at least it's a million times better
than it flowing into the ocean.
Narrator: Boyan says the river plastics
can't be recycled as easily as the ones from the ocean.
Boyan: It's much more of a mix, and also it's much more polluted.
So you have sewage water that's often in these rivers.
Narrator: Ultimately, restoring a polluted ecosystem
requires big changes.
The best way to keep plastic out of rivers and oceans
is to make less of it.
Martin: Everybody can do something,
but we also need the companies to do their part.
This needs to be a collaboration
between all sectors of society.
Narrator: In the meantime,
Carmen does what she can to clean up her own neighborhood.
In her free time, she collects water hyacinths
and transforms them into art.
Narrator: She dries the plant and weaves it into hats,
bags, and more.
Narrator: Much like plastic, the plant can be useful,
but Carmen still wants to see it gone.