Microplastic pollution in oceans vastly underestimated

Microplastic pollution in oceans vastly underestimated

SOURCE: The Guardian DATE: May 22, 2020 SNIP: The abundance of microplastic pollution in the oceans is likely to have been vastly underestimated, according to research that suggests there are at least double the number of particles as previously thought. Scientists trawled waters off the coasts of the UK and US and found many more particles using nets with a fine mesh size than when using coarser ones usually used to filter microplastics. The addition of these smaller particles to global estimates of surface microplastics increases the range from between 5tn and 50tn particles to 12tn-125tn particles, the scientists say. Plastic pollution is known to harm the fertility, growth and survival of marine life. Smaller particles are especially concerning because they are the same size as the food eaten by zooplankton, which underpin the marine food chain and play an important role in regulating the global climate. The new data suggests there may be more microplastic particles than zooplankton in some waters. “The estimate of marine microplastic concentration could currently be vastly underestimated,” said Prof Pennie Lindeque, of the Plymouth Marine Laboratory in the UK, who led the research. She said there may well be even smaller particles than those caught by the fine mesh nets, meaning the numbers “could be even larger again”. Another new study shows how microplastics have entered the food chain in rivers, with birds found to be consuming hundreds of particles a day via the aquatic insects on which they feed. Microplastic pollution has contaminated the whole planet, from Arctic snow and mountain soils to many rivers and the deepest oceans. It is also...
Microplastics disrupt hermit crabs’ ability to choose shell, study suggests

Microplastics disrupt hermit crabs’ ability to choose shell, study suggests

SOURCE: The Guardian DATE: April 29, 2020 SNIP: When it comes to moving home, hermit crabs are experts, often swapping shells for the optimal abode. But now researchers have found that exposure to microplastics disrupts this key behaviour. The finds are the latest to suggest such pollution could be having an impact on the world’s marine creatures. “Usually a so-called ‘normal’ hermit crab will always want to go for the better shell,” said Dr Gareth Arnott, co-author of the new research from Queen’s University Belfast, adding such shells are typically those of sea snails. “The striking thing in this study was when [we offered them a better shell], lots of the crabs that had been exposed to the microplastics didn’t make the optimal decision to take [it],” he said. Microplastics – pieces of plastic 5mm or smaller – are a growing subject of research, with previous studies showing they are present even in the depths of the ocean and are ending up in the bodies of living organisms, from seals to crabs and seabirds. However, while there is some evidence that exposure to such pollution has affected growth and reproduction in some animals, research into specific effects on animal behaviour and cognition remains scarce. Writing in the journal Biology Letters, the team report how they kept each group in the tanks for five days, before removing each crab from its shell and giving it a new shell – crucially, these shells were about half the ideal weight for each crab. After two hours in their new shell, each crab was then put into a deep dish of seawater and...
Penguins’ plastic peril: Scientists warn of growing threat to endangered birds from toxic fibres polluting the ocean

Penguins’ plastic peril: Scientists warn of growing threat to endangered birds from toxic fibres polluting the ocean

SOURCE: Sunday Post DATE: February 10, 2020 SNIP: A study in Antarctic has found that over three quarters of the penguins surveyed in South Georgia had microfibres in their stomachs. Smaller than a baby’s fingernail, and often coated in toxic chemicals, they can lodge in a bird’s stomach, and as they break down into even smaller nanoparticles, wreak havoc throughout the body. Until recently it was believed that the Antarctic, protected by the Circumpolar Current flowing eastward around the uninhabited continent, was a haven from the menace. The island is home to one of the world’s largest colonies of King Penguins, with around 100,000 pairs, and was praised by Sir David Attenborough as one of the most extraordinary places on Earth. Standing over three feet tall, the birds raise just one chick every two years, and have a striking patch of orange-gold feathers on their neck. Lead researcher Camille Le Guen from St Andrews University, who spent over two months on the island, said: “The seas are suffering from climate change, and over-fishing. Plastic pollution is an added and growing threat. “The Southern Ocean was supposed to be the cleanest ocean in the world – but maybe this is not such an isolated place after all. “The Antarctic Circumpolar Current is like a semi-barrier for microfibres, but once they manage to get in, they are stuck because of that current and then they will accumulate.” She added: “We found 77% of birds had microfibres in their diet, birds with chicks and even non-breeding birds.” And almost 300m tonnes of plastic debris are estimated to be floating at sea surface...
The missing 99%: why can’t we find the vast majority of ocean plastic?

The missing 99%: why can’t we find the vast majority of ocean plastic?

SOURCE: The Guardian DATE: December 31, 2019 SNIP: Every year, 8m tons of plastic enters the ocean. Images of common household waste swirling in vast garbage patches in the open sea, or tangled up with whales and seabirds, have turned plastic pollution into one of the most popular environmental issues in the world. But for at least a decade, the biggest question among scientists who study marine plastic hasn’t been why plastic in the ocean is so abundant, but why it isn’t. What scientists can see and measure, in the garbage patches and on beaches, accounts for only a tiny fraction of the total plastic entering the water. So where is the other 99% of ocean plastic? Unsettling answers have recently begun to emerge. What we commonly see accumulating at the sea surface is “less than the tip of the iceberg, maybe a half of 1% of the total,” says Erik Van Sebille, an oceanographer at Utrecht University in the Netherlands. “I often joke that being an ocean plastic scientist should be an easy job, because you can always find a bit wherever you look,” says Van Sebille. But, he adds, the reality is that our maps of the ocean essentially end at the surface, and solid numbers on how much plastic is in any one location are lacking. It is becoming apparent that plastic ends up in huge quantities in the deepest parts of the ocean, buried in sediment on the seafloor, and caught like clouds of dust deep in the water column. Perhaps most frighteningly, says Helge Niemann, a biogeochemist at the Royal Netherlands Institute for Sea...
‘Everywhere we looked’: trillions of microplastics found in San Francisco bay

‘Everywhere we looked’: trillions of microplastics found in San Francisco bay

SOURCE: The Guardian DATE: October 4, 2019 SNIP: The most comprehensive study to date of microplastics in California has turned up a mind-boggling amount of plastic particles in the San Francisco bay. An estimated 7tn pieces of microplastics flow into the San Francisco bay via stormwater drains alone, researchers discovered. Nearly half of the microscopic particles found in stormwater looked suspiciously like tiny fragments of car tires, which rainfall washes off the streets and into the ocean. Treated wastewater contributed an additional 17bn particles of plastic, according to the study. Researchers also found plastic in sediment collected from the bay and its many tributaries and inside the digestive tracts of fish. “It was basically everywhere we looked,” said Rebecca Sutton, an environmental scientist at the San Francisco Estuary Institute, a local institution that led the three-year, $1.1m research effort. [R]esearchers accounted for two types of debris: microplastics, which are particles identified by a laser as fragments of plastic, and microparticles, which are particles the researchers suspect to be plastic, but couldn’t identify as such with the laser. The fragments and fibers they analyzed included the remnants of plastic packaging and bottles, microscopic shreds of cigarette butts and fibers from clothing. Nearly half the particles found in stormwater were “these squishy black particles that we think might be from tires”, Sutton said. “But it’s really hard to get a definitive sense of where exactly it’s all coming from because there are so many sources of plastic pollution.” The study is “extremely comprehensive”, said Stefan Krause, a microplastics researcher at the University of Birmingham. Even as scientists and engineers strive to...