According to a study from 2015 1, between 4.8 to 12.7 million tons of plastic end up in the ocean per year. Everyone has already heard about the “plastic continent” of macro- but mostly microplastic swirling in the world’s gyres. But, everything is connected.
Text: Marie Stetzler
The ocean currents are a huge two-lane-highway around the globe with the water’s salinity and temperature gradients as the main motor of transport: surface currents hence stream in a different (mostly opposite) direction than deep-sea currents. And like on a proper highway, there are plenty of exits, branching out in complex, always thinner paths, leading the currents to the most remote places. That plastic would also end up in the Arctic, transported by the West Spitsbergen Current, was just a matter of time.
Still, it is a bitter reality-check when the lights of our underwater robot the ROV (Remotely Operated Vehicle) laid down on a white plastic bottle. And this at 353m depths and 80° N, miles away from the next soul, and even hundreds from the closest settlement. Our environmental consciousness forbidding us to leave this piece of trash behind, we pick it up with the ROV’s pliers. But even for a piece of plastic scientific interest can be found: the “fouling”, so micro- and macroorganisms which inevitably settle on all submerged surfaces after a while, are worth investigating.
Plastic is a light material, nevertheless, most of it won’t float on the ocean’s surface. It is the weight of the fouling that will drag it down to the bottom of the ocean, as will currents. Around 80% of the plastic in our seas is therefore lying on the ground 2. In absence of light, oxygen, and weathering, it won’t be degraded and can remain there, preserved for centuries, eventually becoming a new habitat for organisms. Not the nicest trace left behind by humankind, but at least this white bottle won’t go down in the geological records of the Anthropocene.
1 Jambeck,J.R., Geyer,R., Wilcox,C., Siegler,T.R., Perryman,M., Andrady,A. ,Narayan, R.,
Law,K.L. (2015) Plastic waste inputs from land into the ocean. Science. 347, 6223, 768–771.
2 François Galgani, French research scientist about ocean plastic at IFREMER. Personal
communication.
