An uninhabited Pacific island thousands of miles away from the nearest city has been named as the most plastic-polluted place on earth. The beaches of the World Heritage-listed Henderson Island, in the Pitcairn Group off South America, contain an estimated 38 million items of debris with a total weight of 17 tonnes.

Image: PNAS

The scientists who discovered the extraordinary level of pollution say this gives the island the highest density of plastic rubbish anywhere in the world. They believe their study is a wake-up call that plastic pollution is as grave a threat as climate change.

International debris

The researchers who surveyed the island’s beaches found rubbish from around the world. Dr Jennifer Lavers found only around 7% of the junk was connected to fishing-related activities.

Image: PNAS

She said most of the things found on the beaches were everyday household items such as cigarette lighters, plastic razors, toothbrushes, plastic scoops used in detergents or baby formula, and babies’ dummies.

“It speaks to the fact that these items that we call “disposable” or “single-use” are neither of those things, and that items that were constructed decades ago are still floating around there in the ocean today, and for decades to come,” said Dr Lavers, “there is nowhere left in the world that is safe — plastic is ubiquitous.”

Just over a quarter of the rubbish came from South America and was the result of the movement of currents in the South Pacific gyre, which flows anti-clockwise after travelling north up the continent.

Image: PNAS

Wider problem

The discovery echoes the findings of a 2016 report by the Ellen MacArthur Foundation, launched at Davos last year, which analysed the flow of materials around the world and predicted that, given the projected growth in production, by 2050 oceans could contain more plastics than fish.

Annual production of plastic has increased from 1.7 million tonnes in 1954 to 311 million tonnes in 2014. An estimated five trillion plastic items — mostly less than five millimetres in size — are already circulating in the surface layer of the world's oceans.

Local impact

Image: PNAS

Not surprisingly, wildlife on Henderson Island has been severely impacted by the plastic waste. While crabs were found to be making use of things like empty cosmetic jars as new homes, dead sea turtles were found tangled in the rubbish.

The island, a territory of the UK, is a sanctuary to a host of threatened species including the Henderson Petrel and Henderson Crake while its beaches are a nesting site for the endangered green turtle.