The most common trash was plastic bags, aluminum cans and fishing equipment. A full third of the garbage was plastic and half of that plastic was bags, which can smother or choke some marine life. Metal junk came in second with aluminum, steel or tin cans making up the majority of that. The rest of the debris was rope, glass, fishing gear, paper and textiles.
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They also discovered that gravity works just the same at sea as on land: Most of the trash was seen below 2,000 meters (6,500 feet). At those depths, the water is pitch black, near freezing and there isn't much oxygen, so biodegrading the debris could take decades.
"I'm sure that there's a lot more debris in the canyon that we're not seeing," said Schlining. "A lot of it gets buried by underwater landslides and sediment movement. Some of it may also be carried into deeper water, farther down the canyon.
She also expressed frustration that the bulk of the trash are recyclables. Ultimately, wrote Schlining and her colleagues, the best approach to reducing deep sea trash is by increasing public awareness.