Microplastic pollution in oceans is far worse than feared, say scientists

The number of tiny plastic pieces polluting the world’s oceans is vastly greater than thought, new research indicates.

The work reveals the highest microplastic pollution yet discovered anywhere in the world in a river near Manchester in the UK. It also shows that the major floods in the area in 2015-16 flushed more than 40bn pieces of microplastic into the sea.

The surge of such a vast amount of microplastic from one small river catchment in a single event led the scientists to conclude that the current estimate for the number of particles in the ocean – five trillion – is a major underestimate.

Microplastics include broken-down plastic waste, synthetic fibres and beads found in personal hygiene products. They are known to harm marine life, which mistake them for food, and can be consumed by humans too via seafood, tap water or other food. The risk to people is still not known, but there are concerns that microplastics can accumulate toxic chemicals and that the tiniest could enter the bloodstream.

“Given their pervasive and persistent nature, microplastics have become a global environmental concern and a potential risk to human populations,” said Rachel Hurley from the University of Manchester and colleagues in their report, published in Nature Geoscience.

Microplastics map

The team analysed sediments in 10 rivers within about 20km of Manchester and all but one of the 40 sites showed microplastic contamination. After the winter floods of 2015-16, they took new samples and found that 70% of the microplastics had been swept away, a total of 43bn particles or 850kg. Of those, about 17bn would float in sea water.

“This is a small to medium sized catchment in the north of England, it is one flood event, it is just one year – there is no way that [5tn global] estimate is right,” said Hurley. The researchers said total microplastic pollution in the world’s oceans “must be far higher”.

The worst hotspot, on the River Tame, had more than 500,000 microplastic particles per square metre in the top 10cm of river bed. This is the worst concentration ever reported and 50% more than the previous record, in beach sediments from South Korea. But Hurley said there may well be worse places yet to me measured: “We don’t have much data for huge rivers in the global south, which may have so much more plastic in.”

“There is so much effort going into the marine side of the microplastic problem but this research shows it is really originating upstream in river catchments,” she said. “We need to control those sources to even begin to clean up the oceans.”

About a third of microplastics found by the team before the flooding were microbeads, tiny spheres used in personal care products and banned in the UK in January. This high proportion surprised the scientists, who said the beads may well also derive from industrial uses, which are not covered by the ban.

Erik van Sebille, at Utrecht University in the Netherlands and and not part of the research team, said the work does support a much higher estimate of global microplastic pollution in the oceans: “I’m not surprised by that conclusion. In 2015, we found that 99% of all plastic in the ocean is not on the surface anymore. The problem is that we don’t know where that 99% of plastic is. Is it on beaches, the seafloor, in marine organisms? Before we can start thinking about cleaning up the plastic, we’ll first need to know how it’s distributed.”

Anne Marie Mahon, at the Galway-Mayo Institute of Technology in Ireland and also not part of the research team, said: “I am actually glad to see the estimate going up a bit, just to show there is this huge contribution coming from the freshwater system.” However, she cautioned that not all the microplastics shown in the study to be flushed out by the floods necessarily entered the sea – some may have been washed over the floodplain instead.

“It is very difficult to tell how this plastic may be affecting us,” Hurley said. “But they definitely do enter our bodies. The missing gap is we need to know if we are getting contaminants inside us as a result of plastic particles.”

The smallest particles that could be analysed in the new research were 63 microns, roughly the width of a human hair. But much smaller plastic particles will exist, and Hurley said: “It is the really small stuff we get worried about, as they can get through the membranes in the gut and in the bloodstream – that is the real fear.”

Why the lynx effect would be a boon for Scotland | Kevin McKenna

During a difficult year, the lynx provided a welcome fragment of good cheer. It seems the big cat could be making a return to the wilds of Scotland after an absence of several hundred years. There are many things to like about the reintroduction of a Champions League predator to the Scottish countryside, not least of which is that it would greatly inconvenience and outrage farming and agricultural types. Indeed, Scotland’s farmers were so perturbed by reports of the lynx’s return that several of them undertook a study trip to Norway for the purpose of building a case against the lynx.

Unsurprisingly, the Norwegian harvesters warned their Scottish brethren that reintroduction of the lynx would be an “absolute catastrophe” for Scotland’s sheep population. The Norwegians claimed that 20,000 sheep were lost last year to the predations of the lynx and unnamed others. Curiously, they couldn’t produce a specific number of deceased sheep that were the sole responsibility of the lynx.

Any study produced after a farmers’ jolly to Scandinavia ought to be treated with extreme caution. These eternal European subsidy junkies have always represented a compelling reason to dislike the European Union. Yet having lived off the fat of farming subsidies for decades, many of them voted to bring us out of Europe. In the case of foot-and-mouth disease, an epidemic that made many farmers rich with swollen payouts, animal hygiene issues were a factor. There was an official investigation into reports that some farmers had deliberately infected their livestock once they discovered the compensation levels.

Reintroduction of the lynx, as well as other big beasties, would be a boon for Scotland. The Lynx UK Trust believes there are many ecological benefits springing from the cat’s return to the Scottish wild. Among these are helping to control deer populations and protecting the capercaillie, one of Scotland’s most cherished big birds, the welfare of which causes many to fret. The trust also points out that overpopulation of deer in Scotland is damaging forest habitats and restricting woodland regeneration.

There are significant ancillary benefits. Scotland’s mountains contribute greatly to the country being consistently voted the world’s most beautiful. Hardly a year passes without Scotland receiving another garland for the beauty and grandeur of its rural landscapes. These jaggy wildernesses are made for top predators, yet apart from a few golden eagles, some osprey and a few wee peregrines, our big spaces have little else but sheep, cows and goats. Even the few decent raptors we’ve got left are at risk of extinction because landowners want to eradicate them to leave plenty of grouse for Prince Harry and his indolent chums to exterminate.

A Eurasian beaver in Tayside, Scotland.

A Eurasian beaver in Tayside, Scotland. Photograph: Nick Upton/Alamy Stock Photo

You can’t get within yards of a decent mountain without a moving sea of blue, yellow and green tramping all over our hills and glens morning, noon and night. Scotland’s national emblem shouldn’t be a thistle – it should be a rucksack. It would be grand to replace some of this seething, sweating river of humanity disfiguring our beautiful places with a few species of serious hunters and biters.

The potential benefits are eye-watering. First, you’d get David Attenborough and his team up here when he gets round to doing a Green Planet or Jaggy Planet series. That would bring in more proper tourism than a few thousand Munro-botherers. And there’s always the joyous possibility of bear or wolves preying on hill walkers and keeping their numbers down to manageable levels.

Yes, yes, yes – I know tourism and “outdoor activities” bring a “much-needed boost” to our economy. Isn’t it curious how that phrase “much-needed boost to the economy” is deployed when the middle classes want to have a party or stretch their legs? Thus Edinburgh’s Hogmanay gives a “much-needed boost” to the economy; hunting and shooting deliver one, too, as do the writhing and perspiring rucksack and cagoule army. Little scrutiny of the phrase “much-needed boost” ever occurs. I doubt whether Edinburgh’s edgier neighbourhoods, such as Pilton and Wester Hailes, share greatly in the “much-needed boost”.

The same siren voices were raised when the beaver was reintroduced to Scotland in Argyll’s Knapdale Forest. Last month, three more beavers were introduced to the forest seven years after the first ones. The success of their reintroduction has exceeded all expectations. Their construction skills make them expert at habitat management to the benefit of Scotland. Their dam-building can stabilise important wetlands during dry months and create still-water pools that become perfect environments for diverse types of insects, such as dragonflies. They can improve biodiversity by ensuring a variety of native tree species flourish.

Unsurprisingly, as with the lynx, the narrow interests of similar opposition groups coalesced in a familiar pattern around the beaver’s reintroduction. Landowners, rich residents, farmers and anglers all opposed the beasts for the flimsiest reasons: houses and business premises could be at risk of flooding. There could be crop damage and an adverse impact on fish stocks. None of this has happened, nor was it ever likely to. As usual, the over-protected interests of privileged groups were being advanced before the interests of the nation. And as usual, their claims went untested.

Some of these landowners are descended from families who participated in an illegal land grab over several hundred years. Having driven people off their lands to make way for sheep, they now try to justify their continued stewardship of these places by saying they are not fit for human communities and that only they possess the skills and experience to manage them properly. So we won’t treat seriously anything they have to say about land conservation and the mix of species that we permit to thrive on them.

Scotland was a home for many of these species well before greedy humans arrived. Our country was designed principally for them. So let’s bring them all back – the lynxes, wolves and bears. This land is their land.