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Plastic Pollution Remains Much Longer Than Previously Thought in River Systems, New Research Finds

24th September 2021
Plastic pollution in our rivers - research has found single-use plastic bottles require UV light to break down over more than 450 years
Plastic pollution in our rivers and seas - research has found single-use plastic bottles require UV light to break down over more than 450 years

Plastic pollution remains in river systems for much longer than previously thought, new research has found. 

Microplastics may travel at less than 0.01km per hour, a University of Leicester study indicates.

Polyethylene terephthalate (PET), a common material for single-use plastic bottles, requires UV light to break down over more than 450 years.

The study involved tracking 90 PET sample plastic bottle ‘tracers’, released into a river Soar tributary near Wistow, Leicester.

The average travel distance for each tracer was 231m in 24 hours, with the furthest at just under 1.1km.

The study was conducted by University of Leicester School of Geography, geology and environment PhD researcher Robert Newbould, alongside Dr Mark Powell and Professor Mick Whelan.

“We were surprised at how easily the plastic bottles were trapped, and their relatively low travel distance,” Newbould said.

“Our work supports other research that existing estimates of riverine plastic flux to the ocean may have been overestimated, but more research is needed to confirm this,”he said.

Researchers recovered 96% of plastic tracers from the river system, and also retrieved other litter to reduce macroplastic pollution.

The University of Leicester is home to the Centre for Landscape and Climate Research, which applies research to pressing global challenges, often in collaboration with industry.

‘Macroplastic Debris Transfer in Rivers: A Travel Distance Approach’ is published in the journal Frontiers in Water.

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Lorna Siggins

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Lorna Siggins

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Lorna Siggins is a print and radio reporter, and a former Irish Times western correspondent. She is the author of Search and Rescue: True stories of Irish Air-Sea Rescues and the Loss of R116 (2022); Everest Callling (1994) on the first Irish Everest expedition; Mayday! Mayday! (2004); and Once Upon a Time in the West: the Corrib gas controversy (2010). She is also co-producer with Sarah Blake of the Doc on One "Miracle in Galway Bay" which recently won a Celtic Media Award

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Marine Wildlife Around Ireland One of the greatest memories of any day spent boating around the Irish coast is an encounter with marine wildlife.  It's a thrill for young and old to witness seabirds, seals, dolphins and whales right there in their own habitat. As boaters fortunate enough to have experienced it will testify even spotting a distant dorsal fin can be the highlight of any day afloat.  Was that a porpoise? Was it a whale? No matter how brief the glimpse it's a privilege to share the seas with Irish marine wildlife.

Thanks to the location of our beautiful little island, perched in the North Atlantic Ocean there appears to be no shortage of marine life to observe.

From whales to dolphins, seals, sharks and other ocean animals this page documents the most interesting accounts of marine wildlife around our shores. We're keen to receive your observations, your photos, links and youtube clips.

Boaters have a unique perspective and all those who go afloat, from inshore kayaking to offshore yacht racing that what they encounter can be of real value to specialist organisations such as the Irish Whale and Dolphin Group (IWDG) who compile a list of sightings and strandings. The IWDG knowledge base has increased over the past 21 years thanks in part at least to the observations of sailors, anglers, kayakers and boaters.

Thanks to the IWDG work we now know we share the seas with dozens of species who also call Ireland home. Here's the current list: Atlantic white-sided dolphin, beluga whale, blue whale, bottlenose dolphin, common dolphin, Cuvier's beaked whale, false killer whale, fin whale, Gervais' beaked whale, harbour porpoise, humpback whale, killer whale, minke whale, northern bottlenose whale, northern right whale, pilot whale, pygmy sperm whale, Risso's dolphin, sei whale, Sowerby's beaked whale, sperm whale, striped dolphin, True's beaked whale and white-beaked dolphin.

But as impressive as the species list is the IWDG believe there are still gaps in our knowledge. Next time you are out on the ocean waves keep a sharp look out!