Subtropical ocean gyres are known to be zones of accumulated floating plastic debris, but polar accumulation has been studied by the EU-funded MICRO B3 project, revealing interesting results.
The FP7-funded MICRO B3 (Marine Microbial Biodiversity, Bioinformatics and Biotechnology) project ended in 2015, but found that although pollution sources were distant, and plastic debris absent in most of the Arctic waters surveyed, it reached high concentrations in the farthest northern and eastern areas of the Greenland and Barents seas.
The scientists analysed the magnitude, distribution and sources of the plastic pollution on the surface waters of the Arctic Ocean based on the Tara Oceans 2013 circumpolar expedition.
During the circumpolar expedition, Dr Andrés Cózar and his colleagues collected floating plastic debris, including fishing lines and a variety of plastic films, fragments and granules. The fragmentation and typology of which led the researchers to conclude the plastic was old and from distant sources.
The paper says: ’The total load of floating plastic for the ice-free waters of the Arctic Ocean was estimated to range from around 100 to 1,200 tonnes, with 400 tonnes composed of an estimated 300 billion plastic items as a midrange estimate.’
Given the wide range, the researchers say the study needs to be considered as a preliminary, first-order approximation.
Testing showed that although the Arctic Polar Circle was slightly polluted with plastic debris, in the Greenland and Barents seas debris was both abundant and widespread.
The team also found that maximum concentrations were lower than in the subtropical accumulation zones but the median values were similar.