Things have become so bad with the human predilection for dumping plastic in the seas that, by the latest predictions, there are now more than five trillion pieces of plastic floating in our oceans.
The study, published this week in PLoS One, saw scientists from across the US, France, Chile, Australia, and New Zealand use data from 24 ocean expeditions in 1,571 locations to reach their conclusions. They found that a staggering 250,000 tonnes of the stuff now bobs in our seas.
Largely it comes from food packaging and clothing, as well as other manmade products. Calling their estimates "highly conservative", they also warn that plastics are now spread across all of the world's oceans. Plastic is now pervasive in our seas.
A back-of-the-envelope calculation shows that the number is equivalent to each human being on the planet having dropped 700 pieces of plastic into the sea. Most of these fragments are small—measuring less than five millimetres—but that isn't necessarily a good thing. Those smaller pieces can, after all, enter the food chain, via fish then all the way up to humans, bringing toxins with them. Julia Reisser, one of the researchers, told the Guardian:
"We saw turtles that ate plastic bags and fish that ingested fishing lines. But there are also chemical impacts. When plastic gets into the water it acts like a magnet for oily pollutants. Bigger fish eat the little fish and then they end up on our plates. It's hard to tell how much pollution is being ingested but certainly plastics are providing some of it."
The study doesn't account for plastics littered along shorelines, nor that already ingested by animals. But given there's so much plastic in our seas that there's a new type of stone that's made up of the stuff, the message is clear: now is a good time to clean up our act. [PLoS One via Verge]
Image by Andrea Zanivan under Creative Commons license.