The Arctic Ocean was for a long time considered as virtually untouched by pollution. But in the past decade, the amount of plastic garbage on the ocean floor has doubled and is now “higher than the amount recorded from a deep-sea canyon not far from the industrialized Portuguese capital Lisbon,” according to a new study.
Plastic garbage doesn’t just float around in the high seas: these remnants of modern civilization also sink to the bottom of the world’s oceans.
Research conducted by the Alfred Wegener Institut für Polar und Meeresforschung (Alfred Wegener Institute for Polar and Marine Research/AWI) shows that it has not only found its way to one of the most remote corners of the planet, but that the amount of plastic debris on the floor of the Arctic Ocean has doubled in the last 10 years.
For her study, published in the Marine Pollution Bulletin, marine biologist Melanie Bergmann compared 2,100 photographs of the deep seafloor taken at the institute’s deep-sea Hausgarten observatory. This observatory is located in the eastern Fram Strait, the sea route between Greenland and Norway’s Spitsbergen Island. The set-up at the station consists of a remote-controlled camera system at a depth of 2,500 meters – about 1.5 meters above the ocean floor – that takes pictures of the seafloor every 30 seconds.
These photographs are generally used to record changes in biodiversity, but as she reviewed the images, Bergmann was struck by the fact that in 2011 a great deal more garbage was visible than had been on photographs from earlier expeditions. "Waste can be seen in around 1% of the images from 2002, primarily plastic," she reports. In 2011, about 2% of the pictures show garbage, leading Bergmann to conclude that the amount of garbage on the ocean has doubled in the past ten years.
The pictures do not reveal where the garbage in the Arctic Ocean comes from. Bergmann suspects that the increased amounts are due to the shrinking and thinning of the Arctic ice, as well as the intensification of ship traffic in the area. Research on the trash picked up on Spitsbergen beaches shows that it comes from high seas fishing boats.
On the ocean floor, “67% of the plastic litter was entangled or colonized by invertebrates such as sponges (41%) or sea anemones (15%).” As plastic bags can affect gas exchange processes, Bergmann believes that it is possible that long-term the trash could change the composition of species and biodiversity on the ocean floor.