British litter-pickers and scientists have teamed up to create an international benchmark for measuring the amount of plastic entering the world’s oceans.
Around 40 volunteers used everyday materials such as jam jars and squeeze bottles to come up with a gold standard for tracking how polluted our rivers are.
They pilot-tested the technique by researchers from the University of Birmingham at dozens of sites across the English Channel, sailing 1,000miles last summer.
The project’s toolkit and results are now being presented at a six-day conference General Assembly of the European Geosciences Union (EGU) in Vienna, Austria.
Professor Stefan Krause, of Birmingham University, in charge of the 100 Plastic Rivers programme, said: “Even if we all stopped using plastic right now, there would still be decades, if not centuries-worth of plastics being washed down rivers and into our seas.
“We’re getting more and more aware of the problems this is causing in our oceans, but we are now only starting to look at where these plastics are coming from, and how they’re accumulating in our river systems.
“We need to understand this before we can really begin to understand the scale of the risk that we’re facing.”
Skipper Nick Beck, 50, ran the Clean Seas Odyssey citizen science scheme with Dr Rebecca Sykes, 36, for three months along the western part of the English Channel.
Mr Beck, of Nottingham, said Prof Krause ordered all their everyday items to conduct their research from online retailer Amazon and had it waiting for them in Plymouth.
He said: “It’s all about proving that anybody can do it – from across the world.
“We were essentially road testing their citizen science idea – which was how to source the samples of micro-plastics collected in a reasonably clean way from river estuaries – although in the end we ended up expanding that.
“There were jar jars. Then a whole lot of distilled water and a few other bits and pieces – squeezy bottles to fire the water out into the jam jars.
“The volunteer group was very similar to what you get if you got to any of the organised beach cleans – it was precisely the same sort of cross section you see there.
“We had quite a cross section from student age all the way through to 70s.
“In the final parts of it we submitted how it could be adapted – we said ‘right, we are going to have to put in in English!'”
He explained volunteers worked across 60 river mouth sites and estuaries.
Across three river depth levels, they waved an empty jam jar in the air and gathered three samples of river water – before analysing what micro-plastics they contained.
Mr Beck, who has skippered the Amelie Rose sailing boat along the Cornish coast since 2009, added: “Every year I’ve been going, the pollution on the beaches has been getting worse and worse.
“That was the trigger for me – that this is just getting completely out of hand.
“The problem is getting worse and the worse thing is we keep pouring the stuff in.
“Essentially good data is how you change public policy.
“When you hand them that and have a replicable tool you can use and a lot of citizens from across the world can use the same tool – that’s the basis with how you can get that change.”
The 100 Plastic Rivers programme is analysing both primary microplastics, such as micro-beads used in cosmetics, and secondary microplastics – from larger plastic items that have broken down in the environment or fibres from clothing.
A key part has been creating a standard method for the sampling and analysis of microplastics in river networks.
The Birmingham research team’s toolkit contains detailed instructions for sampling water and river sediments at locations where stream flow is known or measured.
They also developed methods of automating and thus, objectifying the identification and analysis of microplastics.
They collaborated with the Clean Seas Odyssey citizen science project to test parts of their methodology.
They tested their protocol using the volunteers’ collected samples.
They also conducted data analysis to produce a picture of the different types of plastics accumulated in river sediments at their confluence with the sea.
Prof Krause said the results of this initial survey showed a much wider variety of plastic types in the samples than feared despite the UK’s relative good environmental regulations.