Record Concentrations of Microplastics Found in Arctic Sea Ice

In recent years, research has revealed the troubling extent to which the world's oceans have become inundated with plastic pollution. The situation is so bad that plastic waste has been spotted even in seemingly pristine regions, such as the Arctic or the ocean floor.

Now researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Germany have detected record concentrations of microplastics in Arctic sea ice, according to a study published in the journal Nature Communications.

In addition, they found that this ice transports microplastics across the region and can act as a temporary trap for them, with the potential for large quantities to be released into the oceans as sea ice melts.

Microplastics are tiny plastic particles, fibers, pellets and other fragments with dimensions ranging from just a few micrometers—thousandths of millimeter—to under five millimeters. Many of these plastic particles result from the gradual degradation of larger pieces of plastic waste in the ocean. However, they can also be created directly by various industrial processes on land.

Over the course of three Arctic expeditions in 2014 and 2015 aboard the German icebreaker Polarstern, the AWI researchers collected ice samples from five regions along the Transpolar Drift Stream—a major Arctic Ocean current which transports sea ice to the North Atlantic—and the Fram Strait.

Via a technique known as Fourier Transform Infrared Spectroscopy—which shines infrared light on a sample and uses special mathematical analysis to detect the various substances inside—the team found that the ice contained up to 12,000 microplastic particles per liter, two to three times higher than the team's previous measurements.

Germany's research icebreaker POLARSTERN above the Lomonossov Ridge in the central Arctic Ocean. Alfred-Wegener-Institut / Ruediger Stein

Gunnar Gerdts, one of the authors of the study from AWI, told Newsweek that these values were "extraordinarily" high. "At first, I was surprised since usually we do not find such high numbers in other areas, for instance, the North Sea, etc."

Most of these microplastics were microscopically small, with 67% measuring less than 50 micrometers. This is worrying, according to the researchers, because it means they could easily be ingested by Arctic microorganisms before making their way up the food chain, potentially even reaching humans.

Currently, the effects of consuming microplastics on the health of marine animals and humans are unclear as research is still lacking in this area. And of the studies that have been conducted, many are experimental or work with unrealistically high microplastic concentrations, according to Melanie Bergmann, another author of the Nature study from AWI.

Nevertheless, "we know by now that 1,465 species are affected by litter and microplastic in some way through entanglement, ingestion or colonization of plastic," she told Newsweek. "This number is increasing all the time."

Researchers from the Alfred Wegener Institute collecting Arctic ice samples. Alfred Wegener Institute / M.Fernandez

"I think that evidence is increasing that microplastics have detrimental effects in many cases, such as reduced feeding rates, reduced growth rates, immunological stress, lowered reproductive rates, behavioral changes, decreased fecundity and sometimes mortality," she added.

"When we eat fish, or especially animals that we consume as a whole—such as mussels—humans may also consume microplastics and the associated toxins. But there is still a huge knowledge gap, especially when it comes to particles in the nano-size range."

The researchers also analyzed the unique compositions of the microplastics they found, enabling them to trace the particles back to possible sources. At least 17 different types were identified, including packaging materials like polyethylene and polypropylene, paints, nylon, polyester and cellulose acetate–which is used in the manufacture of cigarette filters.

A view from above of the POLARSTERN research ship. Alfred Wegener Institute / S.Arndt

The high percentage of paint and nylon particles points towards intensified shipping activities in some parts of the Arctic, according to the study, while much of the polyethylene particles are likely remnants of the so-called Great Pacific Garbage Patch. The scientists think these pieces are transported along the Bering Strait and into the Arctic by ocean currents.

The study also shows how ice can transport large quantities of microplastics across the Arctic for several years, before depositing them when it melts. However, it is still unclear whether the deposited particles remain in the Arctic, get transported further south or begin sinking into deeper waters.

So, what insights does the latest research provide with regards to reducing the quantity of microplastics we are pumping into the sea?

An Arctic sea-ice core. Alfred-Wegener-Institut / Tristan Vankann

In the Arctic region, at least, Bergmann thinks curbing the impact of shipping and fishing would be useful.

"In this part of the world, ships have to break the ice and, thereby, probably abrade a greater deal of ship paint then elsewhere, so, the use of other paint may help," she said. "We have to make sure that the gray water of ships that increasingly operate in the area does not contain any microplastic. In addition, I suspect that a number of particles originate from fishing gear. So, we need to work with the fishing industry to reduce gear losses but also switch to the use of nets that don't lose particles."

"Still, since the majority of the pollution is likely transported to the North via the Atlantic, we need to make sure that we reduce our inputs downstream in Europe, but also as far away as the U.S. and South America, from which we also found litter items on Arctic beaches. If we don't turn off the tap and decrease plastic production, the problem will increase."