Between Hawaii and California,Â
--in an area about twice the size of Texas-- Is the Great Pacific Garbage Patch.  For decades, tons of our plastic debris has
accumulated there because of swirling ocean currents. It looks like a cloudy soup: and that’s
because the plastic objects are spaced far apart, and they range in size from large debris
to microscopic.There are at least 4 other garbage patches like this in the world, And
after scientists discovered them, starting in the 90s.  They thought that this might be where a lot
of the plastic ended up, out there floating on the surface. But recently, scientists brought large nets
to the Great Pacific Garbage Patch, and took a closer look at the objects they pulled out. They found water bottles And hard hats
And bottle caps And toothbrushes
And toilet seats And laundry baskets
And using what they found, they were able to calculate how much debris was in all of
the garbage patches. There were about a few hundred thousand tons
of plastics at the surface of the ocean, which is a huge number. It is a big number. But a few hundred thousand metric tons of
plastic is only about 1% of the estimated 8 million tonnes of plastic scientists believe
is emitted into the ocean every year. So scientists have been left investigating
a mystery: Where does the rest of the ocean’s plastic go? Â
This is clue number 1 in the case of the missing plastic: a sea floor sediment sampleÂ
It was taken from the bottom of the Santa Barbara Basin, off the coast of California. It represents a measure of time, from 1870
at its deepest layer of sediment, up until 2009. But this period, from 1945 to 2009, is where
the study authors were focused on. It’s the era of plastic production. In these layers, the study authors found plastic
fibers and fragments that were 1 millimeter or smaller in size. They found more and more plastic particles
as the years went on, doubling every 15 years. That rate is nearly identical to the rate
of global plastic production. Ss soon as you see a layer of microplastic
you pass the 1950’s and that's the legacy of our generation. This is Laurent Lebreton—he works at the
Ocean Cleanup, and led the study of the objects in the Great Pacific Garbage Patch. And this will be there forever. We know that. The sea sediment study looked at microplastics—particles
smaller than 5 millimeters. These either come from clothing fibers, or
they are the result of larger plastics breaking down. We’ve found these tiny particles floating
throughout the ocean, And even in the guts of the ocean’s tiniest creatures, like plankton. But the sediment study shows thatÂ
some of our plastic is likely hiding, buried in the sea floor, too. But here’s another clue: This is a plastic
bag, captured 2,500 meters below the surface of the Arctic deep sea. It’s one of over 2,100 photographs taken
with this deep sea camera. Part of the work that we're doing is to look
at the impact of climate change in the Arctic. We use towed camera surveys to look at the
impact on large animals like starfish and snails, sponges. And while I was doing these surveys, I saw
that more and more plastic debris was on the sea floor. Melanie Bergmann’s research shows that large
plastic objects don’t just float on the surface or degrade into microplastic — some
of them sink without breaking down. One study found that about 50% of plastic
in landfills is more dense than seawater, which means these objects could sink on their
own. But even those other 50 percent may actually
travel to the sea floor with time, because what we see is that the debris which is floating
on the ocean surface becomes colonized with biota over time… barnacles, mussels, all
sorts of different organisms… then it becomes heavier and heavier and at certain at a certain
point and then starts to sink. Bergmann’s research is difficult to replicate
throughout the ocean, because of the challenge of surveying the deep sea environments. But it suggests that some of that missing
plastic might be sitting on the seafloor, intact. Another clue complicates the mystery, though:
this plastic crate, from Taiwan. It’s one of the objects excavated during
that harvest in the Great Pacific Garbage Patch. And what struck researchers was its production
date: 1971. When they looked at the production dates of
other objects, they saw a trend: a lot of it was old trash. This was a new lead: because if the majority
of plastic pollution degraded into microplastic or fell to the ocean floor, then what you’d
see in garbage patches would be new plastic. And that changed the story...the plastic that
is accumulated at the surface of the ocean is actually very persistent. The plastic we find in subtropical oceans
may actually be there for decades, if not centuries. It turns out the new plastic is far closer
than the open ocean or the bottom of the deep sea. Lebreton’s research found that plastic objects
on coastlines have more recent production dates than plastic in the open ocean. This clue led scientists to think a lot of
debris actually stays close to shorelines around the world—hidden in plain sight. Some of that will end up in the middle of
the ocean and garbage patch, but actually a lot of it stays fairly near shore and hop
from beach to beach to beach. Erik Van Sebille is an oceanographer, and
is building an ocean model that predicts where our missing plastic ends up. The completed model will be finished in 2022,
but in the meantime he and his team publish initial results to a Twitter feed. We use simulations of the ocean currents and
they're a bit like weather models for the ocean. So they tell us how the currents are moving
stuff around. And then we put in virtual plastic… And then we move that plastic with the ocean
flow. At the same time the plastic and fragment,
it can degrade, organisms start growing on it that weighs down the plastic so that it
slowly starts to sink into the deeper ocean. So in that way, we're doing like this gigantic
simulation of all of the ocean, of all the plastic moving around. Van Sebille thinks that a majority of plastic
pollution is within 100 miles of shorelines, continually getting washed back up on beaches,
down coastlines, or up and down to the sea floor. If the plastic continuously goes back and
forth between the coastline and offshore, that's a lot of rubbing and fragmenting and
scraping over the sand. This commotion helps explain the presence
of microplastics in sediments and animal guts, too. Laurent’s organization is working on cleaning
up the garbage patches in the middle of the ocean. But that won’t do much for the other 99%
of our plastic: The microplastics becoming part of our food web and geologic record. The larger debris sinking to the bottom of
the ocean. And, more likely than not, getting washed
up on beaches. Like this one, where I recently visited, where
I found a mix of micro and larger plastics. But knowing where plastics end up can help
us keep this plastic heap from growing. These photos were taken by volunteers at an
annual, international coastal clean-up event, organized by the Ocean Conservancy. Where people volunteer to pick up plastic
on beaches near them. The most common objects they find are food
wrappers. Cigarette butts. Plastic bottle caps
And plastic cups and plates. The easiest way to get plastic like this out
of the ocean, is to prevent it from entering in the first place. With better recycling programs. Or producing and using less plastic altogether. There are nearly 400,000 miles of coastline
around the world, not all of it accessible for people. But, knowing that most of our plastic pollution
hangs out along shorelines before it becomes microplastics or floats out to the open sea,
means beach clean-ups can go a long way in preventing further damage. So if you see plastic pollution on a beach—all
the more reason to pick it up.
I watched the whole thing. One thing that I have thought about is that plastic will become like fossils. Archeological digs 1000 years from now will be able to date sites based on the presence of plastics.