Henderson Island is an uninhabited island in the south Pacific Ocean, the largest of the four islands of the Pitcairn Island group and a part of the South Pacific British Overseas Territory. It is also a UNESCO World Heritage Site. UNESCO describes the island as “one of the few atolls in the world whose ecology has been practically untouched by a human presence. Its isolated location provides the ideal context for studying the dynamics of insular evolution and natural selection. ”
Sadly, that description in no longer wholly complete or accurate. It is no longer untouched by humans, nor is it strictly speaking isolated. It lies on the western edge of the South Pacific gyre, a vortex of ocean currents which captures and concentrates floating plastic and trash, at least until the currents wash the plastic onto the beaches of islands like Henderson.
A new study by Dr Jennifer Lavers and Dr. Alexander L. Bond, published in the Proceedings of the National Academy of Sciences, reports that in a 2015 expedition, the researchers documented an estimated 38 million pieces of trash washed up on Henderson’s beaches, amounting to an estimated 17.6 tons of debris on the shores of the tiny island. Dr. Lavers, a research scientist at the University of Tasmania in Australia, told the Australian Broadcasting Corporation that what she saw on Henderson Island was “the highest density of plastic I’ve really seen in the whole of my career.”
Sadly, Henderson Island is not unique. In our post, Choking the Oceans With Plastic, from 2014, we noted that the uninhabited Palmyra Atoll, which lies on the edge of the North Pacific gyre, is also hit by plastic and trash washed ashore by the currents. The beaches are littered with trash and debris. Plastic mooring buoys and plastic bottles are plentiful.
There are five such gyres in oceans around the world. More than 8 million tons of plastic is dumped into our oceans every year.
Thanks to Alaric Bond and David Rye for contributing to this post.