Lost and abandoned fishing gear that is fatal to marine life makes up the majority of major plastic pollution in the oceans, according to a Greenpeace report.

Over 640,000 tonnes of nets, lines, pots and pots used in commercial fishing are thrown and discarded at sea each year, the same weight as 55,000 double-decker buses.

The report, which draws on the most recent research into “ghost craft” polluting the oceans, calls for international action to stop plastic pollution, which is deadly to marine life.

About 300 sea turtles were found dead following an entanglement in ghost craft off the coast of Oaxaca, Mexico, last year. And in October, a pregnant whale was found entangled in ghost gear off the Orkney coast. The fishing gear was stuck in the animal’s baleen, the filter system inside its mouth, and scientists said the net significantly altered the minke’s whale’s feeding and movement.

Louisa Casson, ocean activist at Greenpeace UK, said: “Ghost gear is a major source of plastic pollution in the oceans and it affects marine life in the UK as much as anywhere else.

“The waters of the UK do not exist in a vacuum because the oceans have no borders. Governments around the world must take action to protect our global oceans and hold the under-regulated fishing industry accountable for its hazardous waste. It should start with a strong global ocean treaty to be concluded at the United Nations next year. “

The report says abandoned fishing gear is particularly deadly. “Nets and lines can pose a threat to wildlife for years or decades, trapping everything from small fish and shellfish to endangered turtles, seabirds and even whales,” he said.

“Spreading across the ocean with the tides and currents, lost and discarded fishing gear now drifts to the Arctic coasts, washing up on isolated Pacific islands, entangled in coral reefs and littering the seabed . “

It is estimated that ghost equipment accounts for 10% of plastic pollution in the oceans, but makes up the majority of the large plastics that litter the waters. One study found that up to 70% (by weight) of macroplastics (over 20cm) found floating on the ocean surface were related to fishing.

A recent study of the “Great Pacific Garbage Zone”, an area of ​​plastic accumulation in the North Pacific, estimated that it contained 42,000 tonnes of megaplastics, 86% of which were fishing nets.

Another expedition to the South Pacific found about 18 tons of plastic debris on a 2.5 km stretch of beach on the uninhabited Henderson Island and is believed to be piling up at a rate of several thousand pieces per day. In a collection of 6 tonnes of waste, about 60% came from industrial fishing.

Greenpeace said ghost gear was particularly prevalent in illegal, unregulated and unreported fishing, but overcrowded fisheries also contributed to the problem. “Poor regulation and slow political progress in creating ocean sanctuaries that are closed to industrial fishing allow this problem to exist and persist,” the report said.

Greenpeace calls for the United Nations treaty to provide a comprehensive framework for marine protection, paving the way for a global network of ocean sanctuaries covering 30% of the world’s oceans by 2030.