More than 90% of countries involved in a pollution survey were found to have hundreds of thousands of plastic pellets littering their coastlines, a survey found.

Nurdles, small round pellets produced by the plastics industry, were discovered in 91% of countries (21 out of 23) that took part in the study, including the UK.

The small pellets are melted down to make plastic products, from car parts to medical supplies in countries around the world.

The research was done by the environmental charity Fidra, which organised a Great Global Nurdle Hunt that saw more than 900 volunteers spend a total of 730 hours scouring beaches for the tiny microplastic pellets during October.

The charity’s report said it is estimated 230,000 tonnes – trillions of nurdles – could be lost to the oceans globally, every year.

It references scientific studies which claim nurdles are almost impossible to remove, reuse, or recycle, and have shown that plastic on beaches can release Co2, ethylene, methane and propane gases that all contribute to the greenhouse effect.

Members of the charity, which is based in North Berwick, East Lothian, will be presenting the results of the Nurdle Hunt and the damaging environmental impact of the micro plastic pellets at Cop26 in Glasgow on Tuesday.

Megan Kirton, of Fidra, said: “Cop26 is a real opportunity to highlight pellet pollution to international decision makers and we can’t thank all our volunteers enough for helping us show that this is a widespread global pollution issue that needs action now.

“We can’t keep using energy and fossil fuels to make plastic that ends up in the environment.

“Nurdle pollution demonstrates plastic is being wasted before it has even been used to make anything, which is a huge waste of resources and a threat to wildlife.”

Melissa Nel, a volunteer coordinator and research assistant for the Orca Foundation in South Africa, took part in the hunt and found 10,000 nurdles in two days.

She said: “About one year ago nurdles started washing up in huge numbers along Plettenberg Bays beaches and there has been a huge community drive to help assist in the nurdle problem – which has been amazing.

“But there is still a lot of work to do.

“It is the worst of times, but it is the best of times because we still have a chance to make a difference.”

The 23 countries involved in the survey were: United Arab Emirates, Australia, Belgium, Bangladesh, Brazil, Canada, Chile, China, Costa Rica, Spain, United Kingdom, Guernsey, Greece, Kenya, Sri Lanka, Maldives, Mexico, Netherlands, New Zealand, Portugal, United States, South Africa and Italy.