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.”

Billions of pieces of plastic on coral reefs send disease soaring, research reveals

A major new study estimates 11bn pieces of plastic contaminate vital reefs and result in infections: ‘It’s like getting gangrene,’ scientists warn

Spawning coral wrapped in plastic.






Spawning coral wrapped in plastic.
Photograph: Lalita Putchim/Science

Billions of pieces of plastic pollution are snagged on coral reefs, sending disease rates soaring, new research has revealed. The discovery compounds the damage being done to a vital habitat that already faces an existential threat from the warming caused by climate change.

Scientists examined 125,000 corals across the Asia-Pacific region, home to half the world’s reefs, and found 89% of those fouled by plastic were suffering disease. On plastic-free reefs, only 4% of the corals were diseased.

The work is highly significant because it is the first to examine the impact of plastic on disease in any marine organism and also the first to produce a large-scale estimate of how much plastic pollutes the sea floor. Coral reefs in the region are contaminated with 11bn pieces of plastic, the research indicates.

At least 8 million tonnes of plastic are dumped in the ocean every year and it now pollutes even the remotest corners. Microplastics, formed when plastics are broken up, can be mistaken for food by sea creatures and early studies have shown this causes harm.

The scientists who conducted the new study did not set out to research plastic but were confronted by it across the regions they surveyed. The correlation between plastic pollution and high rates of disease was very striking and the researchers think sharp plastic fragments cut the coral organisms, while plastic fabrics smother them and block out light and oxygen.

“Corals are animals just like me and you – they become wounded and then infected,” said Joleah Lamb, at Cornell University in the US, who led the new research, published in the journal Science. “Plastics are ideal vessels for microorganisms, with pits and pores, so it’s like cutting yourself with a really dirty knife.”

During dives Lamb found objects from plastic chairs to baby nappies to a Nike-branded quick-dry towel: “I saw a big white Nike swoosh, right there where the disease was and thought, ‘oh gosh, this is not great’.”

She said that once a coral is infected, disease usually spreads across the colony: “It’s like getting gangrene on your toe and watching it eat your body. There’s not much you can do to stop it. If a piece of plastic happens to entangle on a coral it has a pretty bad chance of survival.”

Coral reefs are not only a wonder of the natural world, home to myriad spectacular creatures, but they are also vital for at least 275 million people who rely on them for food, coastal protection from storms and income from tourism. The scientists said it is “critical” to cut plastic pollution.

Logos from manufacturing giants, like Nike, can be found along the bottom of the ocean.



Logos from manufacturing giants, like Nike, can be found along the bottom of the ocean. Photograph: Dr. Joleah Lamb/Science

The international team of scientists examined corals spread across 159 reefs off the coasts of Indonesia, Thailand, Myanmar and Australia between 2011 and 2014. They found plastic snared on a third of the individual specimens, with the problem much worse on Indonesian reefs than on the Great Barrier Reef in Australia, where plastic waste is better managed.

The diseases particularly associated with plastic were skeletal eroding band disease, white syndromes and black band disease. Corals with complex branching structures, which provide crucial “nursery” niches for young fish, were eight times more likely to have entangled plastic.

The scientists were only able to record items of plastic more than 5cm in length, so did not assess the impact of microplastics. Lamb also warned: “There are a lot of other pollutants [such as toxic chemicals] in the water that are probably just as bad as plastic – you just can’t see them.”

Prof Terry Hughes, at James Cook University in Australia and not part of the study team, said: “I’d never thought of bits of plastic as a vector of disease spread from the slime that coats them, but the study shows convincingly that corals entangled in plastic are 20 times more likely to be infected.”

Earlier in January, a team led by Hughes published work warning that repeated bleaching events are now “the new normal” due to global warming and pose a fatal threat to reefs. “The new study shows that remote reefs have much less plastic and disease. Unfortunately, there’s nowhere to hide from global warming, and even the most pristine reefs are vulnerable to bleaching,” he said.

Debris lining the beach in Sulawesi, Indonesia.



Debris lining the beach in Sulawesi, Indonesia. Photograph: Dr. Joleah Lamb/Science

Prof Alasdair Edwards, at Newcastle University, UK, and also not involved in the new study, said the combined impact of plastic-related disease and climate change could be very serious: “Warming oceans are still the major threat to corals, but this paper shows that in areas more affected by humans, as exemplified by plastic debris, the chance of corals recovering from mass-bleaching and mortality events may be severely compromised. Corals need all the help they can get.”

Lamb said the one hopeful aspect of the plastic pollution problem was that people can take direct action: “The take-home message for individuals is to be more considered about the amount of single-use plastics you are using and think about where your plastic goes. These little things do matter.”

The researchers also estimated that the plastic pollution tarnishing coral reefs in Asia-Pacific will soar by 40% by 2025 to 16bn pieces, unless action is taken. The true number is likely to be higher, as China and Singapore were not included in the analysis.