Each year 14 million items of plastic end up in canals and rivers in England and Wales, according to a new report.
The Canal and River Trust said more than half a million of these items reach the world’s oceans annually.
The charity said it was “on a mission to eradicate plastic” from its waterways and urged people to pick up any rubbish they find.
It said if every visitor picked up one piece of plastic, the canals and rivers could be plastic-free in a year.
The trust worked with Coventry University to carry out the research for the report.
It took a “snapshot” of the amount of plastics and litter observed at representative locations along 2,000 miles of waterways and found plastics such as bags, bottles, disposable cups and food wrappers accounted for 59% of the waste.
Locations included Leicester, Birmingham, Sheffield, Burnley, Devizes, Tottenham Hale, Torfaen, Milton Keynes, Manchester, Ellesmere Port, Brentford, Worcester, Stratford-upon-Avon, Liverpool, Hemel Hempstead, Oxford and Erewash.
Peter Birch, national environmental policy advisor at the charity, said: “By taking a little care of their local waterway, everyone can have beauty on their doorstep.
“The Canal and River Trust is on a mission to eradicate plastics from our vast network of canals and rivers – helping us all to live in better, more beautiful neighbourhoods, whilst tackling a global issue, and making life better by water.”
Mr Birch added canals and rivers potentially acted as “plastic highways” which was a “huge problem for wildlife”.
The latest study found litter was being dropped over boundary walls from nearby buildings, off bridges and being blown or washed in from areas near the waterways.
The trust said it makes a great effort to minimise litter along waterways and empties 900 public litter bins more than 46,000 times annually.
Volunteers for the charity spend more than 100,000 hours clearing litter from towpaths and canals each year.
The Canal and River Trust
- Launched in 2012, the trust looks after British Waterways’ canals, rivers, reservoirs and docks in England and Wales
- The charity cares for 2,000 miles of waterways
- It spends more than £1m each year to help keep its waters free of plastic and other waste
- Four million people visit the trust’s canals and rivers every two weeks
- The trust also cares for 2,980 bridges, 1,580 locks and 335 aqueducts