Nearly 38 million pieces of plastic have washed up on the beaches of one of the most remote places on earth, with crabs turning discarded rubbish into homes.
Henderson Island, an uninhabited island in the South Pacific Ocean, has the highest density of anthropogenic debris recorded anywhere in the world, with plastic accounting for 99.8% of the pollution.
The island, a Unesco World Heritage Site, is near the centre of the the South Pacific Gyre ocean current, meaning the rubbish carried from South America or deposited by fishing boats accumulates there.
It is located more than 5,000km from the nearest major population centre and has an estimated 37.7 million pieces of plastic.
Experts have been shocked at the volume of plastic found on the island, which is so remote that it is only visited every five to ten years for research purposes.
The expedition was led by the Royal Society for the Protection of Birds (RSPB) and Dr Jennifer Lavers, from the University of Tasmania’s institute for marine and antarctic studies.
Researchers found that the beaches were littered by up to 671 items per square metre, the highest density ever recorded.
Lavers said: “What’s happened on Henderson Island shows there’s no escaping plastic pollution even in the most distant parts of our oceans.
“Far from being the pristine ‘deserted island’ that people might imagine of such a remote place, Henderson Island is a shocking but typical example of how plastic debris is affecting the environment on a global scale.
“Based on our sampling at five sites we estimated that more than 17 tonnes of plastic debris has been deposited on the island, with more than 3,570 new pieces of litter washing up each day on one beach alone.
“It’s likely that our data actually underestimates the true amount of debris on Henderson Island as we were only able to sample pieces bigger than two millimetres down to a depth of 10 centimetres, and we were unable to sample along cliffs and rocky coastline.”
Purple hermit crabs made their homes in plastic containers that had washed up on the beach, the study said, and researchers found an adult female green turtle entangled in fishing line.
Speaking about the sight of the crabs living in rubbish, Lavers told the Guardian: “From the looks on people’s faces, it was quite grotesque,” she said. “That was how I felt about all these crabs – we are not providing them a home, this is not a benefit to them.
“This plastic is old, it’s brittle, it’s sharp, it’s toxic. It was really quite tragic seeing these gorgeous crabs scuttling about, living in our waste.”
The authors of the study, which was published in the journal Proceedings of the National Academy of Sciences, wrote: “The isolation of remote islands has, until recently, afforded protection from most human activities.
“However, society’s increasing desire for plastic products has resulted in plastic becoming ubiquitous in the marine environment, where it persists for decades.”
Lavers said that the majority of the 300 million tonnes of plastic produced worldwide every year is not recycled.
She added: “Plastic debris is an entanglement and ingestion hazard for many species, creates a physical barrier on beaches to animals such as sea turtles, and lowers the diversity of shoreline invertebrates.
“Research has shown that more than 200 species are known to be at risk from eating plastic, and 55 per cent of the world’s seabirds, including two species found on Henderson Island, are at risk from marine debris.”
The study said that most of the debris researchers found on the island originated from fishing-related activities or land-based sources in China, Japan and Chile.