Nine out of 10 seabirds have plastic in their bellies, and by 2050 it will be 99% if humanity keeps clotting the ocean with billions of tons of polyethylene waste, according to a groundbreaking new study.
To come up with those numbers, researchers began by looking at half century of scholarly work on seabirds and plastic. They found that 80 of 135 species had ingested plastic, according to those existing studies, and about a third of those birds still had the plastic pieces—toothpaste caps, shredded bags, cheap toys—swimming in their stomachs when autopsied.
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But those studies date back all the way to 1962, when plastic pollution was a much smaller problem. What if those same studies were all run on birds today? The scholars developed a model to answer that question, and using today's higher concentrations of plastic in the ocean, they came up with that eye-popping figure: 90% of seabirds.
The results were published in the official journal of the National Academy of Sciences.
"They are really striking," lead author Chris Wilcox said in a statement. “This is a huge amount and really points to the ubiquity of plastic pollution."
Plastic production is doubling every 11 years, he and his coauthors report. It has created a soup of plastic in some parts of the ocean, namely the five great garbage patches, where concentrations are as high as 580,000 pieces per square kilometer, and increasing “exponentially.”
“Thus, between 2015 and 2026 we will make as much plastic as has been made since production began,” the authors write. They don’t yet know whether this plastic is tied to the fact that half of all seabird species are in decline, but that’s one hypothesis.
Earlier this year, a different team of scientists published a study that demonstrated just how vast the plastic problem had become, pound for pound. Other studies had looked at the amount of plastic in the oceans; this study, published in the journal Science, looked at plastic at the point of production.
It calculated the annual production of plastic for all 192 coastal countries on Earth, and, among other data, the percentage of plastic that gets “mishandled," ending up in the oceans. The result is hard to comprehend: 10.5 billion to 28 billion pounds of plastic end up in the ocean, every year.
Just imagine how light and thin a piece of plastic can be in your hand. Now imagine how many pieces of plastic it would take to add up to between 10.5 billion and 28 billion pounds.
Jenna Jambeck is a University of Georgia environmental engineer who led the study. She also struggled to help people visualize the amount of plastic we were putting in the oceans. So she came up with a nifty comparison. The scale of humanity's plastic pollution is identical to what would happen if every foot of coastline on Earth were the dumping ground for five grocery bags of plastic trash, Jambeck told National Geographic.
“And by 2025, those five grocery bags are going to be 10 bags,” Jambeck said.
One of the mysteries she and her colleagues uncovered was where all this plastic ends up. Turns out there’s a gap between the amount of plastic sent into the oceans, and the amount of plastic actually found in the oceans when researchers skim the water.
So where does it all go? One partial explanation, it seems, is seabirds.