Large amount of microplastics discovered in arctic ice algae - study

Large amounts of microplastics have been discovered in ice algae located in the Arctic Ocean, according to a study led by researchers from the Alfred Wegener Institute (AWI).

The study was published last week in the peer-reviewed journal Environmental Science & Technology, where researchers stated that plastic pollution has become extremely common to the extent that quantities are even detected in the Arctic.

Researchers observed the ice algae Melosira Arctica and ambient seawater from three locations in the Fram Strait (a passage located between Greenland and the Norwegian archipelago Svalbard). They did so to assess the "microplastic content and potential as a temporary sink and pathway to the deep seafloor."

Researchers state that M. Arctica contains ten times the amount of microplastic particles as its surrounding seawater.

"The speed at which the Alga descends means that it falls almost in a straight line below the edge of the ice," a biologist from the Helmholtz Centre for Polar and Marine Research (AWI) explained. "Marine snow, on the other hand, is lsower and gets pushed sideways by currents so sinks further away. With the Melosira taking microplastics directly to the bottom, it helps explain why we measure higher microplastic numbers under the ice edge."

The study concludes that the high concentration of microplastics found in the study suggests that they're trapped by the M. arctica from ambient seawater and melting ice. It also states that the algae could act as a "key vector to food webs near the sea surface and on the deep seafloor."

A threat to creatures that feed on algae

The concentration of the food web at the sea surface poses a threat to creatures that feed on the algae, researchers stress.

In 2021, a team of scientists conducted a research expedition to the Arctic circle aboard the RV Polarstern icebreaker. 

During the expedition, the team collected three samples of M. Arctica and corresponding clean seawater samples. The samples were collected from seawater near floating sea ice, and precautions were taken to minimize contamination.

The team found microplastic particles in all subsamples collected in the Arctic circle, regardless of polymer type or particle size. The study collected 12 subsamples, which yielded a total of 400 microplastic particles. 

M. Arctica samples contained 5-66 microplastic particles per milligram of wet weight, with an average of 28 microplastic particles per sample. 

The Arctic ecosystem is facing a serious threat from the effects of the ongoing climate crisis, and now the study has found that microplastics are adding to the problem. 

The harmful impact of microplastics on organisms can further weaken their ability to survive. The combination of these two crises has created a planetary emergency that requires urgent attention.

According to an AWI biologist, the most effective way to combat plastic pollution is to reduce the production of new plastic. This approach should be prioritized in the upcoming global plastics agreement currently being negotiated. 

To ensure this, Melanie Bergmann, an AWI biologist, will be attending the next round of negotiations starting in Paris at the end of May.