Study finds Thames is home to some of the highest levels of microplastics of any river in the world

Fall into the Thames these days and you are more likely to choke than drown.

Because the River Thames has some of the highest levels of microplastics of any river in the world, a new study reveals.

Scientists have recorded 94,000 microplastics a second flowing down the river – beating the biggest European rivers, the Danube and Rhine, as well as the Chicago River in the US.

There is some doubt on whether China’s Yangzte river is worse.

Tiny bits of plastic have been found inside the bodies of crabs which live in the Thames.

And flushed away wet wipes are clogging up the shoreline, forming ‘wet wipe reefs’, including on the South Bank near Hammersmith Bridge.

Researchers at Royal Holloway, University of London, are calling for stricter regulations on single-use plastics after finding the native shore crab and the Chinese mitten crab are ingesting microplastics.

And careless disposal of plastic gloves and masks during the coronavirus pandemic might make the problem worse, they warn.

Professor Dave Morritt, from Royal Holloway, said: “The increased use of single-use plastic items, and the inappropriate disposal of such items, including masks and gloves, along with plastic-containing cleaning products, during the current Covid-19 pandemic, may well exacerbate this problem.”

The Thames is cleaner than it used to be for some pollutants, such as trace metals, they say.

But glitter and microbeads from cosmetics, fibres from washing machine outflows and potentially from sewage outfalls were among the pollutants.

Most of the microplastics were from large bottles and food packaging.

Crabs contained tangled plastic in their stomachs, including fibres and microplastics from sanitary pads, balloons, elastic bands and carrier bags.

About 95 per cent of mitten crabs were found to have tangled plastic in their stomachs.

Clams near the wet wipe ‘reefs’ contained synthetic polymers, possibly from the wet wipes and sanitary items.

Researcher Alex McGoran said: “Tangles of plastic were particularly prevalent in the invasive Chinese mitten crab, and we still don’t fully understand the reason for this.”

The research was carried out by the Royal Holloway with Natural History Museum (NHM) and the Zoological Society of London (ZSL).

In total, 135 crabs were examined and 874 pieces and tangles of plastic, mainly in the form of fibres, were removed from their bodies.

Frequently these fibres form tangles of up to 100 pieces of plastic, filling the stomach of many crabs.

Anna Cucknell, ZSL’s Thames Project Manager, said: “Plastic pollution is devastating for aquatic ecosystems, and I was shocked by the densities we found.

“Thanks to decades of conservation two species of seal and more than 100 species of fish including sharks, seahorses and the Critically Endangered European eel, call the Thames Estuary home.

“We must not let plastic pollution threaten their survival.”