The remote island of Henderson—a tiny dot in the South Pacific Ocean—lies approximately halfway between New Zealand and Chile. It is one of four islands that make up the Pitcairn Group. It was here, in 1789, the mutineers of the HMS Bounty sought safe heaven, eventually settling on the island of Pitcairn, located some 190 km away from Henderson. Pitcairn is the only inhabited island in the group. No one lives on Henderson Island, and aside from an occasional visit from scientists and Pitcairn’s dwindling population, there are hardly any tourists here. The nearest major landmass is more than 5,000 kilometers away.

Photo credit: Jennifer Lavers

Yet strangely, Henderson Island is not untouched by human influence. What should have been pristine sandy beaches are littered with trash—fishing nets and floats, water bottles, helmets, and large, rectangular pieces of plastic. Researchers estimate there are some 38 million pieces of plastic, weighing 18,000 kg in total, scattered around the island’s waterfront. The majority of the debris—approximately 68 percent—is not even visible; they are buried under the sand.

Every square meter of Henderson’s beaches has between 20 and 670 pieces of plastic on the surface and between 50 and 4,500 pieces buried in the topmost 10 centimeters. About 3,750 new pieces of litter wash up on the island’s north beach everyday. If these estimates are correct, Henderson Island might have the highest densities of plastic pollution reported anywhere in the world.

Where do all these trash come from? The giant plastic soup called the ocean, of course. Henderson Island lies on the outskirts of the Southern Pacific Gyre, a large rotating ocean current circling between Australia and South America, bounded by the Equator. The gyre's rotational pattern draws in trash from across the South Pacific Ocean and far-off continents and deposits them on Henderson’s shore. A similar phenomenon occurs in the Northern hemisphere, where plastic from around the North Pacific Ocean gets washed onto Hawaii’s Kamilo beach.

Jennifer Lavers, a scientist at the University of Tasmania who lead the research, have traced the source of the debris on Henderson Island to 24 different countries from every continent.

Once plastic lands on the island, irradiation from the sun’s UV rays makes the plastic brittle and they break apart into hundreds or even thousands of pieces, some of which are less than 2 millimeters across. They become buried in the sand and became a permanent part of the island.

Sadly, the whole place was declared a World Heritage Site by the United Nations in 1988. The UNESCO’s website still describes the island as “one of the few atolls in the world whose ecology has been practically untouched by human presence.”

A purple hermit crab on Henderson Island. Photo credit: Jennifer Lavers

Trash on Henderson Island. Photo credit: Jennifer Lavers

Photo credit: Ron Van Oers/Wikimedia