River Mersey contains more plastic pollution than the Great Pacific Garbage Patch

Researchers collected 942 microplastic pieces by sampling the water surface at two locations on the Mersey for half an hour each - equating to more than 2 million pieces of microplastic per square kilometre.

This is double the 1 million pieces per sq km found at one of the most plastic-polluted expanses of water on earth the Great Pacific Garden Patch.

The research was conducted by scientists and campaigners who collected water samples in February and March at separate points along 13 rivers.

Each of the samples were then analysed by Greenpeace scientists at the University of Exeter by using a cutting-edge infrared plastic detector called a fourier-transform infrared spectrometer (FTIR).

Greenpeace are now putting pressure on the Government to set 'legally-binding' plastic reduction targets in the upcoming Environment Bill.

Steve Backshall, wildlife expert and TV presenter, said: “I’ve seen the impact that plastic pollution has on wildlife first-hand, and it’s crushing to see birds feeding plastic to their young and using it to build their nests.

"Greenpeace's study has discovered that the River Mersey is even more polluted than the Great Pacific Garbage Patch – surely this will galvanise us all into doing something about this.

“Plastic pollution isn't just a domestic issue, its impacts are seen on wildlife and humans all over the world.

"For the sake of nature and for the sake of future generations we need to stop producing so much of it – it’s the only way forward."

Plastic samples from the River Mersey (Alex Hyde / Greenpeace)

Each of the 13 UK rivers tested contained microplastics, which are small plastic particles less than 5 mm in diameter and are often fragments from degraded items like plastic bottles, packaging and bags.

Five out of the 13 contained microbeads which were partially banned in 2017 and more than half the rivers tested contained plastic pellets called ‘nurdles’which are used as a raw material in the production of plastic products.

Dr David Santillo, senior scientist with the Greenpeace Research Laboratories at the University of Exeter said: “The results of this report speak for themselves.

"Every single river we tested contained microplastic, and given what is known already about the effects of plastics on marine wildlife, it is reasonable to assume that the plastic pollution of our rivers poses some level of threat to river wildlife. "There is an urgent need for research to better understand those threats, as well as the risks to human health.

“We ignore this problem at our peril. Once microplastics are in the river, they become impossible to remove again, so we have to solve the problem at the source."

Last week it emerged that humans could be ingesting the equivalent of one credit card’s worth of microplastic every week through dinking the likes of bottled water and beer and eating things such as shellfish and salt but it is not known what impact this will have on human health.

Fiona Nicholls ocean plastics campaigner for Greenpeace UK, said: “It’s been almost two years since Blue Planet 2 – and yet plastic use is still set to skyrocket.

“This study is a wake-up call for government.

"Fiddling around the edges of the plastic pollution problem by banning straws just doesn’t cut it.

"We need to see bold new plastic reduction targets in the upcoming Environment Bill, and aim to at least halve single use plastic production by 2025."

The report findings will be presented at a parliamentary event today (June 19) where Steve will speak and MPs will be urged to sign up in support of plastic reduction targets.