There are now at least five major garbage patches in the world's oceans, and much of that trash is plastic. But last month researchers said they can only account for one percent of the plastic they'd expect to find in the oceans. So, where'd the rest of it go?
Well, animals eat some of it. Plastic has been found in turtles, seabirds, fish, plankton, shellfish, even bottom-feeding invertebrates. But there's another way sea creatures might be accumulating plastic: by sucking up tiny plastic particles with their siphons and gills.
Researchers added common shore crabs—Carcinus maenas—to tanks of seawater containing millions of tiny plastic particles, just 10 microns in diameter. After 16 hours, all the crabs had plastic lodged in their gills. And the particles stuck around for up to three weeks, too. The results are in the journal Environmental Science and Technology. [Andrew J. R. Watts et al, Uptake and Retention of Microplastics by the Shore Crab Carcinus maenas]
The longer plastic sits in an animal, researchers say, the better the chances it will travel up the food chain. Meaning all our plastic waste could come back to bite us—or rather be bitten by us.
"Of course we eat mussels whole, without the shells. But we're potentially eating plastic, if they're from a site where there's plastic present." Lead researcher Andrew Watts, of the University of Exeter. "We don't know how much plastic we have in our stomachs… chances are we do have some."
[The above text is a transcript of this podcast.]