Henderson Island Displays Devastating Scale of Plastic Pollution
A remote, uninhabited island in the South Pacific has been discovered to contain the world’s largest documented accumulation of debris by area.
Henderson Island, a British overseas territory and part of the Pitcairn Islands group, is just over 14 square miles in size and is more than 3,000 miles from the nearest major landmass, and yet is reported to swamped by at least 17 tonnes of plastic and other debris.
A report published in the Proceedings of the National Acadamy of Sciences (PNAS), by Jennifer Lavers (Institute for Marine and Antarctic Studies, University of Tasmania) and Alexander Bond (Centre for Conservation Science, Royal Society for the Protection of Birds), contains some absolutely staggering information regarding the scale of plastic accumulation on the small island’s beaches.
The report estimates that up to 37.7 million debris items have accumulated on the island, with up to 671.6 individual items per square metre, ranging in size from particles of just a few millimetres in size to much larger objects. The report calculates that around 26.8 new items per square metre wash up along the shoreline – an average of almost 28,000 individual pieces of debris in total – every day.
Furthermore, the report later states that ‘Although alarming, these values underestimate the true amount of debris, because items buried [more than] 10cm below the surface and particles [smaller than] 2mm (5mm in the beach-back area) and debris along cliff areas and rocky coastlines could not be sampled.’
Part of the reason for the accumulation of plastic debris lies in the location of Henderson Island at the western boundary of the South Pacific Gyre, the prevailing current which rotates anticlockwise along the western coast of South America in the direction of Australia.
Oceanic gyres are known to accumulate a huge amount of plastic debris – indeed – the North Pacific Gyre has become colloquially known as the ‘Great Pacific Garbage Patch,’ although the name is somewhat misleading as the vast majority of the ‘garbage’ consists of microscopic particulate matter, rather than a floating waste disposal site.
Nevertheless, the horrific figures from Henderson Island put the scale of the world’s plastic pollution problem into perspective, when one considers that Henderson is but a minute landmass in a circular current which rotates around an area of ocean approximately twice the size of Australia.
'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,' said Dr. Lavers. 'Research has shown that more than 200 species are known to be at risk from eating plastic, and 55 per cent of the word's seabirds, including two species found on Henderson Island, are at risk from marine debris.'
Some 98 per cent of the debris found on Henderson Island is plastic, and packaging information shows that it comes from locations as distant as Japan and Chile, much of it several years old. The report notes that 61.8 per cent of the recorded items found on the beaches are classed as 'microplastics', a much greater threat to many species than larger items, as they are too small to be seen and therefore easily ingested.
According to some statistics, An estimated 300 million tons of plastic products are produced every year, of which some 8 million tons ends up in the ocean, a sobering thought considering that 17 tons of it have found their way to this tiny little island in the middle of the South Pacific Ocean.