Yet more research has highlighted the escalating environmental threat posed by microplastics.
British scientists found small synthetic fibres in the guts of every one of the 102 sea turtles they studied: more than 800 particles in all, and they only looked at a part of each gut. The total present, they suspect, was as much as 20 times higher.
And the problem is widespread. The turtles were from seven species and three parts of the world: off North Carolina, US, in the Atlantic Ocean, Northern Cyprus in the Mediterranean, and off Queensland in the Pacific.
The most common particles were fibres, which can come from such diverse sources as clothing, tyres, cigarette filters, ropes and fishing nets.
The most affected turtles were from the Mediterranean, but the sample size and methodology did not allow for detailed geographical comparisons.
The study was carried out by the University of Exeter and Plymouth Marine Laboratory, working with the Greenpeace Research Laboratories. The findings are reported in a paper published in the journal Global Change Biology.
The researchers don’t know how synthetic particles are ingested by turtles – the likely sources are polluted seawater and sediments and eating via prey or plants – or what their effect is. But they’d like to.
“Their small size means they can pass through the gut without causing a blockage, as is frequently reported with larger plastic fragments,” says lead author Emily Duncan.
“However, future work should focus on whether microplastics may be affecting aquatic organisms more subtly. For example, they may possibly carry contaminants, bacteria or viruses, or they may affect the turtle at a cellular or subcellular level.”
Nick Carne is the editor of Cosmos Online and editorial manager for The Royal Institution of Australia.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.