Microplastics have been found in the sharks that live near the seabed off the Cornwall coast.
University of Exeter scientists studied four species of seabed-dwelling shark.
Of the 46 sharks examined, 67% contained microplastics and other man-made fibres.
A total of 379 particles were found and – though the impact on the sharks’ health is unknown – the researchers say it highlights the “pervasive nature of plastic pollution”.
"Our study presents the first evidence of microplastics and anthropogenic fibre contaminants in a range of native UK shark species," said lead author Kristian Parton, of the Centre for Ecology and Conservation at the Penryn Campus in Cornwall
He added: "We were surprised to find not only microplastics but also particles such as synthetic cellulose, which is most commonly found in textiles (including disposable hygiene items like facemasks) and clothing.
"When clothes are washed, or items are discarded as litter, tiny fibres are released and these often flow into water sources and out to sea."
Once in the sea, microfibres can either float or sink to the bottom, which is where these sharks live.
"The fibres could then be ingested via the sharks’ food, which is mostly crustaceans, or directly through the sediment on the seabed.
"In terms of the other types of microplastics we found, many of these may have come from fishing lines or nets."
The research team examined the stomachs and digestive tracts of four species: small-spotted catshark, starry smooth-hound, spiny dogfish and bull huss.
Though the study is based on a modest sample size, the findings suggest larger sharks contained more particles. No differences were found based on sex or species.
The study was conducted using sharks caught as “bycatch”, or by accident, in a demersal hake fishery.
Study co-author Professor Tamara Galloway, said: “We were not expecting to find microfibres from textiles in so many of our native shark species.
“Our study highlights how important it is to think before we throw things away.”