Having written about ocean plastics yesterday, I thought I might mention a new bit of research from a friend of mine from university. Andrew Watts, a marine biologist at Exeter University, is suggesting that the danger to marine life from plastics may be worse than previously thought, because plastics can be inhaled as well as ingested.
Working with fluorescently labelled polystyrene, the team showed how tiny microspheres of plastic can be absorbed into the bodies of shore crabs through the gills. Studies into plastic in the marine environment have so far focused on how sea creatures ingest it through eating. The possibility that it can be breathed in as well hasn’t had as much attention, but it may be important – the study shows that plastic absorbed in this way remains in the body longer, and therefore increases the chances of it passing up the food chain.
It is estimated that 11 million tonnes of plastic end up in the oceans every year, much of it packaging. Plastic does not biodegrade, but UV light and the movement of the waves break it down into smaller and smaller pieces, and eventually into microparticles small enough to enter through the gills.
Some plastic comes in micro-size from the start, such as the microbeads used to give texture to cosmetics and toothpastes. We used to use salt crystals or ground nut shells for this sort of thing, but plastics are now common. A tub of exfoliant scrub could be 10% plastic beads. Since they are too tiny to be caught by filtering systems, they end up in the sea, then in fish, and potentially in our own bodies.
There are campaigns working to get microbeads banned, with some success. The Plastic Soup Foundation is one of them, and Andy recommends their Beat the Microbeads app, which you can use to scan barcodes and see if companies use the material in their products.
The images that spring to mind when thinking about plastics in our oceans tend to be dolphins caught in nets, or the contents of birds’ stomachs that photographer Chris Jordan recorded in his Midway project. The tiny bits of plastic that we don’t see could be just as dangerous, and we’re only just beginning to understand their effects.