Coastlines of remote, sparsely inhabited South Atlantic territories such as Tristan da Cunha, Ascension and the Falkland Islands, have, until recently, showed minimal evidence of human interference. ‘Three decades ago these islands, which are some of the most remote on the planet, were near-pristine,’ says Dr David Barnes, from the British Antarctic Survey (BAS). This is no longer true.
BAS research reveals that these island outcrops have experienced a one hundred-fold increase in debris – predominantly plastic, comprising more than 90 per cent – washing in from the ocean over the intervening 30 years. ‘In 2018 we recorded up to 300 items per metre of shoreline on East Falkland and St Helena,’ says Barnes. ‘This is ten times higher than recorded a decade ago.
In recent years the BAS research ship RRS James Clark Ross undertook four research cruises in the South Atlantic, surveying the density of plastic and other debris on the sea surface, on the seabed, in the water column, inside native fauna and on shorelines. Levels of shoreline plastic are now comparable to those observed on highly populated coasts in North America, with around a third being comprised of microplastics (smaller than 5mm). They also counted plastic inside 2,243 animals, spanning 26 different species and the entire food chain, from zooplankton up to seabirds.
‘With all the initiatives and awareness, I had expected stabilisation – or possibly even an improvement – of the problem,’ says Barnes. While he emphasises the importance of cutting off the supply of plastic waste at the source, he also points to a series of local engagement projects on these islands that look to minimise the issue. ‘There are only small communities on Ascension Island and Tristan da Cunha, but there have been beach cleans and even scuba operations to try and clean plastics up in local environments,’ he outlines. ‘In the Falklands there have been even more concerted efforts with substantial clean-ups and surveys, and they have already been in contact with us about trying to do more. St Helena is really pushing on this, and as well as surveys, beach and scuba cleans, and nearshore water sampling, now it has won a new grant specifically to target plastic waste.’