Tourists are being urged to reduce their use of plastic as new figures reveal holidaymakers cause a 40% spike in marine litter in the Mediterranean each summer.

Nearly all the waste created by the surge in tourism over the summer months in countries like Italy, France and Turkey is plastic litter, says WWF in a new report.

In a matter of weeks over the holiday season the rise in plastic marine pollution contributes to the estimated 150m tonnes of plastic in the ocean.

Quick guide Plastics and our throwaway society Show Hide Why is plastic being demonised? Since the 1950s, 8.3bn tonnes of plastic has been produced. Plastic is seen as a versatile, indispensable product, but the environmental impact is becoming more stark. Plastic is now so pervasive that recycling systems cannot keep up and the leakage into the environment is such that by 2050 plastic in the ocean will outweigh fish. In 2017 scientists found plastic fibres in tap water, and plastic has been found in the stomachs of sea creatures in the deepest part of the ocean. Most plastic waste ends up in landfill sites or leaks into the natural environment, where it is causing huge damage to eco-systems on land and sea, creating near permanent contamination. According to academics in the United States, by 2015, of all the plastic waste generated since the 1950s, only 9% has been recycled, with 12% incinerated and 79% accumulated in landfill sites or the environment. Why are the supermarkets under fire? Producers of plastic include retailers, drinks companies and supermarkets. Supermarkets create more than half of the plastic waste in the household stream in the UK. But they refuse to reveal how much they put on to the streets and how much they pay towards recycling it. Supermarkets are under pressure to reduce their plastic packaging and campaigners argue they have the power to turn off the tap. Much of the packaging they sell to consumers is not recyclable: plastic film, black plastic trays, sleeves on drinks bottles and some coloured plastic. The Recycling Association and other experts believe supermarkets could do much more to make packaging 100% recyclable and reduce the use of plastic. Who pays to clean up the waste? The taxpayer, overwhelmingly. UK producers and retailers pay among the lowest towards recycling and dealing with their waste in Europe. In other countries, the “polluter” is forced to pay much more. In France, a sliding system of charges means those who put more non- recyclable material on the market pay more. What can shoppers do to help? Supermarkets are under pressure, not least from the prime minister, to create plastic-free aisles. A growing number of zero-waste shops are springing up and consumers are being encouraged to ask for products to be sold without plastic. Sandra Laville Photograph: ermingut/E+

WWF said in its report the majority of plastic waste polluting the Mediterranean Sea comes from Turkey and Spain, followed by Italy, Egypt and France – countries to which more than 34 million British holidaymakers are preparing to travel this year.

Tanya Steele, chief executive of WWF, said holidaymakers were leaving behind a toxic legacy of plastic waste.

“The birds, fish and turtles of the Mediterranean are choking on plastic … plastic is ending up in the fish and seafood we eat on holiday.

“We’re asking people to think about how they can cut down on the amount of single-use plastic they use and throw away on holiday,” she said.

Steele urges holidaymakers to drink tap water where it is safe to do so, refuse plastic straws and skip the purchase of inflatable pool toys.

“We can all be part of the solution and not the problem,” she said.

Recent pictures of Bournemouth beach after the Bank Holiday weekend in the UK showed mountains of plastic waste littered across the sand.

In Europe plastics account for 95% of the waste in the open sea, posing a major threat to marine life, says WWF.

After China, Europe is the second largest producer of plastic in the world, producing 27m tonnes of plastic waste. The continent dumps up to an estimated 500,000 tonnes of macroplastics and 130,000 tonnes of microplastics in the sea every year, the report says.

But delays and gaps in plastic waste management in most Mediterranean countries mean only a third of the 60m tonnes of plastic produced is recycled. Half of all plastic waste in Italy, France and Spain ends up in landfills.

Home to almost 25,000 plant and animal species – of which 60% are unique to the region – the Mediterranean holds only 1% of the world’s water but contains 7% of all of the world’s microplastic waste. Plastics have also been found in oysters and mussels, while crisp packets and cigarettes have been found in large fish, WWF says.

Plastic waste remains in the environment for hundreds of years. Every plastic cup left by a tourist on a beach takes 50 years to break down, every plastic bag takes 20 years, and a fishing line can remain in the sea for up to 600 years, the report said.

The Mediterranean, semi-enclosed by three continents and home to intense human activity, creates a trap for plastics which today account for 95% of marine litter in the sea.

But Europe is in danger of being left behind on action against single-use plastic by emerging economies. In the most ambitious global action yet to curb plastic waste, India this week announced it was banning all single use plastics by 2022.