Why 99% of ocean plastic pollution is "missing"

00:09:00
https://www.youtube.com/watch?v=fsjvwQclGLo

摘要

TLDRThe video explores the Great Pacific Garbage Patch, a massive accumulation of plastic debris between Hawaii and California. Scientists have found that only a fraction of the plastic in the ocean is on the surface, leading them to investigate where the rest might be. Studies suggest that missing plastic could be in the form of microplastics in sea sediments or nearer to coastlines than previously thought. The video also highlights the persistence of plastics in the ocean and the role of coastal clean-ups in mitigating the problem. Efforts are underway to model and track oceanic plastic to better understand its fate and prevent further pollution.

心得

  • 🌊 The Great Pacific Garbage Patch is vast but isn't where most oceanic plastic resides.
  • 🔍 Scientists search for missing plastics, suspecting sea floor and coastal proximity.
  • 📈 Plastic particles in sediments increase with global production rates.
  • 🦠 Microplastics, from breakdown or synthetic fibers, are endangering marine life.
  • 📅 Plastic debris can persist in the ocean for decades or longer.
  • 🌐 Ocean current models predict plastic movements and accumulations.
  • ⚓ Dense plastics may sink to the ocean floor without breaking down.
  • 🏝️ Large quantities of plastics remain close to shorelines.
  • 🧼 Beach clean-ups play a crucial role in controlling ocean pollution.
  • ❌ Preventing plastic entry into oceans starts with better waste management.

时间轴

  • 00:00:00 - 00:09:00

    The Great Pacific Garbage Patch, located between Hawaii and California, is one of several oceanic garbage patches filled with plastic debris accumulated over decades due to ocean currents. Despite the vast amount of plastic expected in oceans, recent findings show only a small fraction is visible at the surface. This mystery of the missing plastic suggests that some could be microplastics embedded in sea floor sediments or submerged large objects due to their density or biological colonization. Notably, older debris is found in the open ocean, while newer plastic remains closer to shorelines, constantly moving between beaches and the ocean, fragmenting over time. This cycle helps explain the widespread presence of microplastics. Efforts to model ocean currents and plastic movement enhance understanding, suggesting much plastic stays near coasts. Preventing plastic from entering oceans through improved recycling or reduced use, and conducting beach clean-ups are crucial strategies to mitigate pollution.

思维导图

视频问答

  • What is the Great Pacific Garbage Patch?

    The Great Pacific Garbage Patch is a large area between Hawaii and California, where tons of plastic debris accumulates due to ocean currents.

  • How much plastic waste is in the ocean's surface?

    There are a few hundred thousand metric tons of plastic on the ocean’s surface, which is only about 1% of the estimated 8 million tonnes emitted annually.

  • Where might the missing ocean plastic be?

    Missing ocean plastic may be buried in sea floor sediments, floating near coastlines, or degraded into microplastics.

  • What are microplastics, and how do they form?

    Microplastics are particles smaller than 5mm, formed from the breakdown of larger plastic items or from synthetic fibers.

  • Why is it significant that some plastic objects are old?

    Old plastic objects suggest that they persist in the ocean for decades, contradicting the idea that all plastics degrade quickly or sink.

  • What role do coastal areas play in plastic pollution?

    Coastal areas are significant in plastic pollution, with much debris getting washed up on beaches or staying near shorelines.

  • How is plastic pollution impacting marine life?

    Plastic is found in the guts of marine creatures like plankton and can impact ecosystems as it fragments and breaks down.

  • What are the implications of plastic on the sea floor?

    Plastic on the sea floor, often older, suggests that much debris sinks and remains intact for extended periods.

  • What methods are used to study oceanic plastic distribution?

    Researchers use ocean current simulations and deep-sea camera surveys to understand how plastic moves and accumulates.

  • How can beach clean-ups help?

    Beach clean-ups can reduce the amount of plastic entering the ocean, thus preventing further environmental damage.

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  • 00:00:01
    Between Hawaii and California,  --in an area about twice the size of Texas--
  • 00:00:05
    Is the Great Pacific Garbage Patch.
  • 00:00:08
    For decades, tons of our plastic debris has accumulated there because of swirling ocean
  • 00:00:13
    currents.
  • 00:00:14
    It looks like a cloudy soup: and that’s because the plastic objects are spaced far
  • 00:00:18
    apart, and they range in size from large debris to microscopic.There are at least 4 other
  • 00:00:25
    garbage patches like this in the world, And after scientists discovered them, starting
  • 00:00:30
    in the 90s.
  • 00:00:31
    They thought that this might be where a lot of the plastic ended up, out there floating
  • 00:00:36
    on the surface.
  • 00:00:37
    But recently, scientists brought large nets to the Great Pacific Garbage Patch, and took
  • 00:00:43
    a closer look at the objects they pulled out.
  • 00:00:46
    They found water bottles And hard hats And bottle caps
  • 00:00:51
    And toothbrushes And toilet seats
  • 00:00:54
    And laundry baskets And using what they found, they were able
  • 00:00:57
    to calculate how much debris was in all of the garbage patches.
  • 00:01:01
    There were about a few hundred thousand tons of plastics at the surface of the ocean, which
  • 00:01:05
    is a huge number.
  • 00:01:06
    It is a big number.
  • 00:01:08
    But a few hundred thousand metric tons of plastic is only about 1% of the estimated
  • 00:01:13
    8 million tonnes of plastic scientists believe is emitted into the ocean every year.
  • 00:01:19
    So scientists have been left investigating a mystery: Where does the rest of the ocean’s
  • 00:01:25
    plastic go?
  • 00:01:32
    This is clue number 1 in the case of the missing
  • 00:01:34
    plastic: a sea floor sediment sample  It was taken from the bottom of the Santa
  • 00:01:39
    Barbara Basin, off the coast of California.
  • 00:01:42
    It represents a measure of time, from 1870 at its deepest layer of sediment, up until
  • 00:01:48
    2009.
  • 00:01:49
    But this period, from 1945 to 2009, is where the study authors were focused on.
  • 00:01:55
    It’s the era of plastic production.
  • 00:01:58
    In these layers, the study authors found plastic fibers and fragments that were 1 millimeter
  • 00:02:03
    or smaller in size.
  • 00:02:06
    They found more and more plastic particles as the years went on, doubling every 15 years.
  • 00:02:12
    That rate is nearly identical to the rate of global plastic production.
  • 00:02:16
    Ss soon as you see a layer of microplastic you pass the 1950’s and that's the legacy
  • 00:02:21
    of our generation.
  • 00:02:23
    This is Laurent Lebreton—he works at the Ocean Cleanup, and led the study of the objects
  • 00:02:27
    in the Great Pacific Garbage Patch.
  • 00:02:29
    And this will be there forever.
  • 00:02:32
    We know that.
  • 00:02:34
    The sea sediment study looked at microplastics—particles smaller than 5 millimeters.
  • 00:02:39
    These either come from clothing fibers, or they are the result of larger plastics breaking
  • 00:02:45
    down.
  • 00:02:46
    We’ve found these tiny particles floating throughout the ocean, And even in the guts
  • 00:02:50
    of the ocean’s tiniest creatures, like plankton.
  • 00:02:54
    But the sediment study shows that  some of our plastic is likely hiding, buried
  • 00:02:59
    in the sea floor, too.
  • 00:03:02
    But here’s another clue: This is a plastic bag, captured 2,500 meters below the surface
  • 00:03:11
    of the Arctic deep sea.
  • 00:03:13
    It’s one of over 2,100 photographs taken with this deep sea camera.
  • 00:03:18
    Part of the work that we're doing is to look at the impact of climate change in the Arctic.
  • 00:03:25
    We use towed camera surveys to look at the impact on large animals like starfish and
  • 00:03:34
    snails, sponges.
  • 00:03:35
    And while I was doing these surveys, I saw that more and more plastic debris was on the
  • 00:03:41
    sea floor.
  • 00:03:42
    Melanie Bergmann’s research shows that large plastic objects don’t just float on the
  • 00:03:47
    surface or degrade into microplastic — some of them sink without breaking down.
  • 00:03:54
    One study found that about 50% of plastic in landfills is more dense than seawater,
  • 00:03:59
    which means these objects could sink on their own.
  • 00:04:02
    But even those other 50 percent may actually travel to the sea floor with time, because
  • 00:04:09
    what we see is that the debris which is floating on the ocean surface becomes colonized with
  • 00:04:15
    biota over time… barnacles, mussels, all sorts of different organisms… then it becomes
  • 00:04:20
    heavier and heavier and at certain at a certain point and then starts to sink.
  • 00:04:25
    Bergmann’s research is difficult to replicate throughout the ocean, because of the challenge
  • 00:04:30
    of surveying the deep sea environments.
  • 00:04:32
    But it suggests that some of that missing plastic might be sitting on the seafloor,
  • 00:04:39
    intact.
  • 00:04:41
    Another clue complicates the mystery, though: this plastic crate, from Taiwan.
  • 00:04:45
    It’s one of the objects excavated during that harvest in the Great Pacific Garbage
  • 00:04:50
    Patch.
  • 00:04:51
    And what struck researchers was its production date: 1971.
  • 00:04:56
    When they looked at the production dates of other objects, they saw a trend: a lot of
  • 00:05:00
    it was old trash.
  • 00:05:03
    This was a new lead: because if the majority of plastic pollution degraded into microplastic
  • 00:05:08
    or fell to the ocean floor, then what you’d see in garbage patches would be new plastic.
  • 00:05:14
    And that changed the story...the plastic that is accumulated at the surface of the ocean
  • 00:05:19
    is actually very persistent.
  • 00:05:21
    The plastic we find in subtropical oceans may actually be there for decades, if not
  • 00:05:30
    centuries.
  • 00:05:32
    It turns out the new plastic is far closer than the open ocean or the bottom of the deep
  • 00:05:37
    sea.
  • 00:05:39
    Lebreton’s research found that plastic objects on coastlines have more recent production
  • 00:05:45
    dates than plastic in the open ocean.
  • 00:05:47
    This clue led scientists to think a lot of debris actually stays close to shorelines
  • 00:05:51
    around the world—hidden in plain sight.
  • 00:05:54
    Some of that will end up in the middle of the ocean and garbage patch, but actually
  • 00:05:58
    a lot of it stays fairly near shore and hop from beach to beach to beach.
  • 00:06:03
    Erik Van Sebille is an oceanographer, and is building an ocean model that predicts where
  • 00:06:08
    our missing plastic ends up.
  • 00:06:09
    The completed model will be finished in 2022, but in the meantime he and his team publish
  • 00:06:15
    initial results to a Twitter feed.
  • 00:06:17
    We use simulations of the ocean currents and they're a bit like weather models for the
  • 00:06:21
    ocean.
  • 00:06:22
    So they tell us how the currents are moving stuff around.
  • 00:06:23
    And then we put in virtual plastic…
  • 00:06:24
    And then we move that plastic with the ocean flow.
  • 00:06:27
    At the same time the plastic and fragment, it can degrade, organisms start growing on
  • 00:06:33
    it that weighs down the plastic so that it slowly starts to sink into the deeper ocean.
  • 00:06:38
    So in that way, we're doing like this gigantic simulation of all of the ocean, of all the
  • 00:06:43
    plastic moving around.
  • 00:06:45
    Van Sebille thinks that a majority of plastic pollution is within 100 miles of shorelines,
  • 00:06:52
    continually getting washed back up on beaches, down coastlines, or up and down to the sea
  • 00:06:56
    floor.
  • 00:06:57
    If the plastic continuously goes back and forth between the coastline and offshore,
  • 00:07:04
    that's a lot of rubbing and fragmenting and scraping over the sand.
  • 00:07:09
    This commotion helps explain the presence of microplastics in sediments and animal guts,
  • 00:07:16
    too.
  • 00:07:18
    Laurent’s organization is working on cleaning up the garbage patches in the middle of the
  • 00:07:24
    ocean.
  • 00:07:25
    But that won’t do much for the other 99% of our plastic: The microplastics becoming
  • 00:07:30
    part of our food web and geologic record.
  • 00:07:33
    The larger debris sinking to the bottom of the ocean.
  • 00:07:35
    And, more likely than not, getting washed up on beaches.
  • 00:07:40
    Like this one, where I recently visited, where I found a mix of micro and larger plastics.
  • 00:07:46
    But knowing where plastics end up can help us keep this plastic heap from growing.
  • 00:07:52
    These photos were taken by volunteers at an annual, international coastal clean-up event,
  • 00:07:57
    organized by the Ocean Conservancy.
  • 00:07:59
    Where people volunteer to pick up plastic on beaches near them.
  • 00:08:03
    The most common objects they find are food wrappers.
  • 00:08:06
    Cigarette butts.
  • 00:08:08
    Plastic bottle caps And plastic cups and plates.
  • 00:08:11
    The easiest way to get plastic like this out of the ocean, is to prevent it from entering
  • 00:08:16
    in the first place.
  • 00:08:17
    With better recycling programs.
  • 00:08:19
    Or producing and using less plastic altogether.
  • 00:08:22
    There are nearly 400,000 miles of coastline around the world, not all of it accessible
  • 00:08:28
    for people.
  • 00:08:29
    But, knowing that most of our plastic pollution hangs out along shorelines before it becomes
  • 00:08:33
    microplastics or floats out to the open sea, means beach clean-ups can go a long way in
  • 00:08:39
    preventing further damage.
  • 00:08:42
    So if you see plastic pollution on a beach—all the more reason to pick it up.
标签
  • Ocean pollution
  • Plastic debris
  • Microplastics
  • Great Pacific Garbage Patch
  • Sea floor
  • Ocean currents
  • Marine life
  • Plastic waste
  • Environmental impact
  • Coastal clean-up