Research team including UYA member Erik van Sebille: The global 'plastic flood' reaches the Arctic
Even the High North can’t escape the global threat of plastic pollution. This alarming picture emerges from an inventory of dozens of studies into microscopically small plastic particles in the Arctic region. An international team of researchers, including Utrecht University oceanographer and UYA member Erik van Sebille, publishes the inventory today in the journal Nature Reviews Earth & Environment.
The numbers speak for themselves. Today, between 19 and 23 million metric tons of plastic litter per year end up in the waters of the world – that’s two truckloads per minute. Since plastic is also very stable, it accumulates in the oceans, where it gradually breaks down into ever smaller pieces. The tiniest bits of plastic, microplastics, and nanoplastics, can even enter the human bloodstream. And the flood of debris is bound to get worse: global plastic production is expected to double by 2045.
Ocean currents transport our waste
The consequences are serious. Today, virtually all investigated marine organisms, from plankton to sperm whales, encounter plastic debris and microplastics. And this applies to all areas of the world’s oceans, from tropical beaches to the deepest oceanic trenches.
As the study by Erik van Sebille and colleagues shows, the High North is no exception. "This overview study shows once again how ocean currents transport our waste to the most remote corners of our planet," said Van Sebille.The inventory was a joint effort between researchers from Canada, Germany, Norway and the Netherlands, led by scientists from Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI).
"The Arctic is still assumed to be a largely untouched wilderness," says AWI researcher Dr Melanie Bergmann. "Our northernmost ecosystems are already particularly hard hit by climate change. This is now exacerbated by plastic pollution. And our own research has shown that the pollution continues to worsen."
The inventory paints a grim picture. Although sparsely populated, virtually habitats in the Arctic show a similar level of plastic pollution as densely populated regions around the globe. The pollution stems from both local and distant sources. Especially ocean currents from the Atlantic and the North Sea, and from the North Pacific over the Bering Strait, contribute to this.
Plastic pollution in rivers
Tiny microplastic particles are also carried northward by the wind. In addition, rivers also contribute to plastic pollution. Although the Arctic Ocean makes up only one percent of the total volume of the world’s oceans, it receives more than 10 percent of the global water discharge from rivers. These rivers carry plastic into the ocean, for example from Siberia. When seawater off the coast of Siberia freezes in the autumn, suspended microplastic becomes trapped in the ice. The Transpolar Drift transports the ice flows to Fram Strait between Greenland and Svalbard, where it melts in the summer, releasing its plastic cargo.
Sources of plastic pollution
Major local sources of pollution include municipal waste and wastewater from Arctic communities. Plastic debris also originates from ships. Especially nets and ropes from fishing vessels pose a serious problem. Either intentionally dumped in the ocean or unintentionally lost, they account for a large share of the plastic debris in the European sector of the Arctic. On one beach on Svalbard, almost 100 percent of the plastic mass washed ashore came from fisheries.
Microplastic could affect sea ice and snow
"Unfortunately, there are very few studies on the effects of plastic on marine organisms in the Arctic," Bergmann explains. "But there is evidence that the consequences there are similar to those in better-studied regions. Many Arctic animals, such as polar bears, seals, reindeer, and seabirds become entangled in plastic and die. And just as in any other part of the world, unintentionally ingested microplastic likely leads to reduced growth and reproduction, to physiological stress and inflammations in the tissues of marine animals."
The available data on potential feedback effects between plastic debris and climate change is particularly thin. "There is an urgent need for further research into this," says Bergmann. "Initial studies indicate that trapped microplastic changes the characteristics of sea ice and snow."
Intensifying global warming
For example, dark plastic particles could mean the ice absorbs more sunlight and therefore melts more rapidly. In turn, due to what is known as ice-albedo feedback this can intensify global warming. Moreover, plastic particles in the atmosphere provide condensation nuclei for clouds and rain, which means they could influence the weather and, in the long term, the climate. And last but not least, throughout their lifecycle, plastics are currently responsible for 4.5 percent of global greenhouse-gas emissions.
Same pollution levels, worse consequences
"Our review shows that the levels of plastic pollution in the Arctic match those of other regions around the world. This concurs with model simulations that predict an additional accumulation zone in the Arctic," said Bergmann. "But the consequences might be even more serious. As climate change progresses, the Arctic is warming three times faster than the rest of the world. Consequently, the plastic flood is hitting ecosystems that are already seriously strained."
This gives us yet another reason to prevent plastic from entering our environment.
Van Sebille strongly advocates reducing plastic waste worldwide, to prevent further pollution. This also holds true for his home country the Netherlands. "Plastic pollution that enters Dutch sea waters, may eventually end up in the Arctic. Ecosystems over there are already under enormous pressure due to climate change. This gives us yet another reason to prevent plastic from entering our environment."