Wildlife conservationists have started an investigation after a section of a south Devon river was found to be littered with plastic. During a recent clean-up, 10 volunteers collected about 30 bags of rubbish between Dittisham and Lower Gurrow Point on the River Dart.
The Devon Wildlife Trust is looking at how a high number of plastic drinks containers came to be in the river.
The trust said such litter was a persistent problem to wildlife.
Sian Rees, the trust's Dart catchment project officer, said: "Litter is a problem because it can be mistaken for food and ingestion can lead to infections, starvation, fatal blockages and the build up of toxic substances.
"Plastic is of particular environmental concern as it does not degrade quickly, it simply breaks down into smaller pieces.
"All litter once belonged to someone and it is important for both people and wildlife that everyone takes steps to reduce the amount of litter they create and to dispose of it responsibly."