Decline in plastic bags on seabed suggests measures to tackle waste are working

The number of plastic bags found on the seabed has plummeted, suggesting efforts to combat plastic pollution are working.

Government scientists compiled data on 25 years’ worth of plastic trawled from the bottom of the sea to examine litter trends in the waters surrounding the UK.

While the findings have been heralded as evidence of successful policies to reduce plastic pollution, experts say the report shows that other items need to be dealt with as vigorously as plastic bags.

Despite the reduction in carrier bags, the overall amount of deep-sea litter remained roughly constant due to an increase in the number of other plastic items, including bottles and fishing debris.

The new research comes shortly after another report produced for the government that concluded the amount of plastic in the world’s oceans is set to treble within a decade.

Pledging to tackle this “scourge”, the government has implemented various measures to deal with plastic waste – most recently bottle deposit schemes.

Charges on supermarket carrier bags have led to an 80 per cent drop in plastic bag use across England, and ministers have hailed this move as a victory in the war on plastic waste.

The scientists behind the new research at the Centre for Environment, Fisheries and Aquaculture Science (Cefas) have suggested the trend they observed on the sea floor could be partly a result of this action.

“It is encouraging to see that efforts by all of society, whether the public, industry, NGOs or government to reduce plastic bags are having an effect,” said Dr Thomas Maes, a marine litter scientist at Cefas and the report’s lead author.

“We observed sharp declines in the percentage of plastic bags as captured by fishing nets trawling the seafloor around the UK compared to 2010 and this research suggests that by working together we can reduce, reuse and recycle to tackle the marine litter problem.”

The findings by Dr Maes and his colleagues were based on the analysis of nearly 2500 ocean trawls conducted by ships between 1992 and 2017.

Over the entire 25-year period, more than 60 per cent of all trawls contained plastic litter. These results were published in the journal Science of the Total Environment.

Past research has found plastic to be pervasive across marine ecosystems, with litter found at the poles and at the bottom of deep sea trenches.

The impact of plastic in the marine environment is still poorly understood. However, animals are known to die after consuming or becoming tangled in litter, and plastic has even been implicated in spreading diseases around coral reefs.

In Theresa May’s 25-year environment plan, launched in January, she said the success of the 5p plastic bag charge “shows the difference which government action can make”.

Since then, minsters have considered the introduction of a similar charge on disposable coffee cups, as recommended by the Environmental Audit Committee.

Such measures have been backed by The Independent’s own Cut the Cup Waste campaign, which found the majority of the British public would be in favour of a 25p charge added to coffee cups.

However, ministers rejected the levy proposal in March, drawing criticism from environmental organisations.

Mary Creagh, who chairs the committee, said the new evidence from Cefas supported the need for such a levy.

“This research shows how effective charges are at reducing plastic waste,” she said.

“The UK has used 9 billion fewer plastic bags since the 5p charge was introduced. Ministers should introduce a 25p ‘latte levy’ to tackle the UK’s mountain of coffee cup waste.”

This sentiment was echoed by environmentalists, who welcomed the apparent decline in plastic bags but urged the need for further action.

“It’s great that the bag levy appears to have cut plastic bags in our seas, but much tougher action is needed if we’re to tackle the huge plastic pollution crisis – including microplastics – swamping our marine environment,” said Friends of the Earth plastics campaigner Julian Kirby.

“Our seabeds are becoming dumping grounds for plastic, which is proving devastating for wildlife. Out of sight, shouldn’t mean out of mind,” said Dr Lyndsey Dodds, head of marine policy at WWF.

“Taxes and levies are a good step – the reduction in plastic bags entering the ocean is proof of this – but we need the government to be thinking bigger and putting an end to the use of all avoidable single-use plastic by 2025.”

Commenting on the Cefas report, a spokesperson from the Department for Environment, Food and Rural Affairs said: “This report clearly shows our 5p plastic bag charge has made a significant impact in reducing plastic in our oceans, taking 9 billion bags out of circulation since it was introduced.

“While we have made great strides, we recognise more needs to be done – which is why we’re introducing a deposit return scheme, subject to consultation, and exploring how changes to the tax system could reduce waste from single-use plastics such as coffee cups.”