UK river more polluted than Great Pacific Garbage Patch

The UK’s River Mersey contains proportionally more plastic pollution than the infamous Great Pacific Garbage Patch, an area recognised by scientists as one of the most plastic-polluted expanses of water on earth


This was one of the findings of a new scientific study released by Greenpeace (2) which reveals that every one of 13 UK rivers tested were contaminated with microplastics (3).

  • Every UK river tested by Greenpeace found to contain microplastics
  • River Mersey is proportionally more polluted than the Great Pacific Garbage patch
  • Government urged to introduce plastic reduction targets and create environmental watchdog in upcoming Environment Bill

Greenpeace is urging the UK government to set legally-binding plastic reduction targets in the upcoming Environment Bill and to create an independent environmental watchdog with proper powers to enforce those targets.

Scientists and campaigners collected water samples in February and March at separate points along each of the 13 rivers, which were analysed by Greenpeace scientists at the University of Exeter using a cutting-edge infrared plastic detector called a fourier-transform infrared spectrometer (FTIR).

In the first nationwide exercise of its kind, experts found:

  • All 13 UK rivers tested contained microplastics
  • A total of 1,271 pieces of plastic, ranging in size from straw and bottle-top fragments to tiny microbeads less than 1mm across
  • The River Mersey was proportionally more polluted than the Great Pacific Garbage Patch – containing equivalent to 2 million pieces of microplastic per square km
  • Five out of 13 rivers contained microbeads – which were partially banned in 2017
  • More than half the rivers tested contained plastic pellets called ‘nurdles’, which are used as a raw material in the production of plastic products

Microplastics are small plastic particles, less than 5 mm in diameter, that are often fragments of larger degraded items like plastic bottles, packaging and bags. Scientific research has found that when eaten by wildlife, such as fish, microplastics can cause gut blockage, alter feeding behaviour, growth rates and reproduction(4). Previous research has shown that bacteria are able to latch onto pieces of plastic which can cause disease to spread (5) and also that microplastics can both attract and leach out harmful chemicals (6)

Last week it emerged that humans could be ingesting the equivalent of one credit card’s worth of microplastic every week, via drinking common beverages including bottled water and beer and eating common food-stuffs such as shellfish and salt (7). The human health impact of this is not yet clear.

The report findings will be presented at a parliamentary event today [19 June] where wildlife expert and TV presenter Steve Backshall will speak and MPs will be urged to sign up in support of plastic reduction targets . 90 MPS have already pledged their support (8).

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 simply 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”.

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.”

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”.


(1). In the Mersey, researchers found a total of 942 plastic pieces across both samples taken. Using the same measure other studies have used, if we were to extrapolate our findings for the Mersey, we would find it contains more than 2 million pieces of microplastic per square kilometre, a number higher than that found at the infamous Great Pacific Garbage Patch that accumulates within the North Pacific Gyre (Moore et al. 2001, found a max. of 334,271 pieces per square kilometre; Law et al. 2014, found more than 1 million pieces per square kilometre).

(2) Download our report here:

(3) We tested rivers across England, Wales, Scotland and Northern Island –  the Exe, Thames, Severn, Great Ouse Trent, Mersey,Aire, Derwent, Wear, Conwy, Wye, Clyde and Lagan.







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