Scientists at the University of Cádiz found single-use bags, plastic bottles, food containers and food wrappers are the four most widespread items polluting the seas and accumulating along shorelines and near-shore waters.
Just 10 plastic products, also including plastic lids and fishing gear, accounted for three-quarters of the litter, due to their extensive use and slow degradation.
The results from the study led to scientists calling for bans on some common throwaway items and for producers behind the items to take more responsibly.
Carmen Morales-Caselles, at the University of Cádiz, Spain, who led the new research, told the Guardian: “We were not surprised about plastic being 80 per cent of the litter, but the high proportion of takeaway items did surprise us, which will not just be McDonald’s litter, but water bottles, beverage bottles like Coca-Cola, and cans.
“This information will make it easier for policymakers to actually take action to try to turn off the tap of marine litter flowing into the ocean, rather than just clean it up,” she said.
Straws and stirrers made up 2.3 per cent of the litter and cotton buds and lolly sticks were 0.16 per cent.
“It’s good that there is action against plastic cotton buds, but if we don’t add to this action the top litter items, then we are not dealing with the core of the problem – we’re getting distracted,” Ms Morales-Caselles said.
The research, published in the journal Nature Sustainability, concluded: “In terms of litter origins, take-out consumer items – mainly plastic bags and wrappers, food containers and cutlery, plastic and glass bottles, and cans – made up the largest share.”
It comes as 80 countries signed up to an international target to protect at least 30 per cent of the world’s ocean by 2030.
Countries including India, Guyana, South Korea and Austria have pledged to support the “30by30” commitment which is being championed by the UK-led Global Ocean Alliance and the High Ambition Coalition for Nature and People, co-chaired by the UK, Costa Rica and France.
Environment Secretary, George Eustice, said: “The UK is a global leader in marine protection, and we are leading the way internationally to deliver healthy and sustainable seas.
“We must strike a balance in supporting sustainable industries while increasing protections for our seas.”