Plastic Waste On The High Seas Comes From Merchant Ships And Fishing Vessels


Rachel Baxter

Copy Editor & Staff Writer

A cargo ship crossing the open ocean. Avigator Fortuner/Shutterstock

Inaccessible Island, an extinct volcano at the heart of the South Atlantic, sandwiched between South America and Africa but incredibly far from each, is perhaps one of the last places on Earth you’d expect to be littered with plastic trash. But, like many remote islands, it is, and a new study sheds light on why.

After it was highlighted by distressing footage in the BBC series Blue Planet 2, the plastic crisis surged into the spotlight. Various governments pledged to ban single-use plastics and reduce waste, while many members of the public turned away from bottled water and plastic straws, cutlery, and Q-tips in favor of less environmentally damaging alternatives.


However, a new study published in the Proceedings of the National Academy of Sciences suggests that consumers of plastics on land are just a part of the problem. It seems huge amounts of ocean plastics originate on merchant ships.

The team behind the new study collected thousands of pieces of plastic on Inaccessible Island in 1984, 2009, and 2018 and worked out where they came from. At first, much of the plastic appeared to have traveled to the islands from South America, however, by 2018 three-quarters of the plastic was found to have come from Asia, with China being the biggest culprit.

Study co-author Maëlle Connan assessing plastic bottles on Inaccessible Island. University of Cape Town

An overwhelming majority of plastic bottles washed up on the island had arrived there since 2016, but it would take at least three years for them to be swept across the oceans from East Asia. Therefore, it seems China’s rapidly expanding fleet of merchant ships is to blame.

Many of the bottles had been squashed in a space-saving fashion to maximize onboard storage. However, it seems crew aboard merchant vessels toss their vast collections of plastic waste overboard, instead of disposing of it once reaching port. Chucking waste overboard in this way has been banned since 1989 under the International Convention for the Prevention of Pollution from Ships.


So much plastic builds up on Inaccessible Island because it sits in the South Atlantic gyre, an immense collection of swirling currents. Plastic caught up in these currents gets swept into a grim assemblage of floating waste, known as an oceanic garbage patch. When it comes to who to blame for these masses of trash, the finger is often pointed at consumers and their penchant for buying throwaway plastics. While this is certainly part of the problem, and is responsible for much of the litter found in coastal areas, it’s important to remember the huge role that industry plays in polluting our seas. Today, about 2,400 ships pass by Inaccessible Island each year.

The countries where Inaccessible Island's plastic bottles were manufactured. University of Cape Town

“Recent studies of litter in the North Pacific garbage patch and remote islands in the Pacific Ocean show that fishing gear and other shipping-related equipment account for much of the mass of plastic at sea,” said lead researcher Peter Ryan, an expert on marine plastics at the University of Cape Town.

“The challenge comes in understanding the origin of ‘general’ litter – food packaging and domestic products – which could come from ships or land-based sources.”

To tackle the issue, we need to identify the source of the problem, and out on the high seas that source is cargo ships and fishing vessels.


"Everyone talks about saving the oceans by stopping using plastic bags, straws and single-use packaging. That's important, but when we head out on the ocean, that's not necessarily what we find," oceanographer Laurent Lebreton told AFP.