Plastic Bag Found at the Bottom of the Mariana Trench

The Mariana Trench—the deepest point in the ocean—extends nearly
36,000 feet down in a remote part of the Pacific Ocean. But if you
thought the trench could escape the global onslaught of plastics
pollution, you would be wrong.

A recent study^[1]
revealed that a plastic bag, like the kind given away at grocery
stores, is now the deepest known piece of plastic trash, found at a
depth of 36,000 feet inside the Mariana Trench. Scientists found it
by looking through the Deep-Sea
Debris Database^[2], a collection of photos
and videos taken from 5,010 dives over the past 30 years that was
recently made public.

Of the classifiable debris logged in the database, plastic was
the most prevalent, and plastic bags in particular made up the
greatest source of plastic trash. Other debris came from material
like rubber, metal, wood, and cloth, and some is yet to be
classified.

Most of the plastic—a whopping 89 percent—was the type of
plastic that is used once and then thrown away, like a plastic
water bottle or disposable utensil.

While the Mariana Trench may seem like a dark, lifeless pit, it
hosts more life than you might think. NOAA’s Okeanos
Explorer vessel searched
the region’s depths in 2016^[3]
and found diverse life-forms, including species like coral,
jellyfish, and octopus. The recent study also found that 17 percent
of the images of plastic logged in the database showed interactions
of some kind with marine life, like animals becoming entangled in
the debris.

The new study is just one among many showing just how prevalent
plastic pollution has become worldwide. Single-use plastics are
virtually everywhere, and they may take hundreds of years or more
to break down once in the wild.

Last February, a separate study^[4]
showed that the Mariana Trench has higher levels of overall
pollution in certain regions than some of the most polluted rivers
in China. The study’s authors theorized that the chemical
pollutants in the trench may have come in part from the breakdown
of plastic in the water column.

Plastic has recently become a greater focus of the environmental
movement, being featured prominently this
past Earth Day^[5], for example. While
plastic can enter the ocean directly, such as trash blown from a
beach or discarded from ships, a study^[6]
published in 2017 found that most of it is flowing into the sea
from 10 rivers that run through heavily populated regions.

Discarded fishing gear is also a major source of plastic
pollution, and a study published last March found that the material
comprised the bulk of the Texas-size Great
Pacific Garbage Patch^[7]
floating between Hawaii and California.

While the ocean clearly contains much more plastic than a single
plastic bag, the item has now gone from a wind-flung metaphor for
listlessness to an example of how deep an impact humans can have on
the planet.