Microplastics: Researchers discover record levels in Arctic ice
25 Apr 2018 --- The highest amounts of microplastics ever recorded have been discovered in the Arctic Sea ice. On average, 12,000 pieces of microscopic particles were detected per liter of ice across five sample locations, with the research team identifying plastic packaging and increased shipping and fishing in the Arctic as the primary causes.
The research – published in Nature Communications – found that the microplastics had been locked in the ice for up to seven years and that the levels were two to three times higher than previous measurements. Different samples identified higher concentrations of certain types of plastic, with particularly high amounts of polyethylene – plastic commonly used in packaging – traced from the Pacific inflow via the Bering Strait to the waters of the Arctic.
Ice cores were tested from five regions of the Arctic Ocean in the spring of 2014 and summer of 2015. "Using this approach, we also discovered plastic particles that were only 11 micrometers across," said co-researcher Gunnar Gerdts of the Alfred Wegener Institute. "That's roughly one-sixth the diameter of a human hair, and also explains why we found concentrations of over 12,000 particles per liter of sea ice - which is two to three times higher than what we'd found in past measurements."
Overall, 17 different types of plastics were discovered in the ice, including those commonly used in packaging materials, paint particles from ships and fishing nets, and cellulose acetate from cigarette filters.
Lead author, Dr. Ilka Peeken, states concern over the potential impact on local marine life: “Microplastics could easily be ingested by Arctic (single-celled) microorganisms like ciliates, but also by copepods (a group of small crustaceans. No one can say for certain how harmful these tiny plastic particles are for marine life, or ultimately also for human beings."
The study suggests that “these fragments represent remains of the so-called Great Pacific Garbage Patch,” a gyre of marine debris comprising plastic and other forms of material waste in the central North Pacific ocean, discovered between 1985 and 1988.
The microplastics could remain frozen in the ice for up to 11 years before melting into the sea. Scientists are unaware of what happens at this point, although a popular theory is that the particles end up on the seafloor.
"Free-floating microplastic particles are often colonized by bacteria and algae, which makes them heavier and heavier. Sometimes they clump together with algae, which makes them drift down to the seafloor much faster," explains AWI biologist and co-author Dr. Melanie Bergmann. "We recently recorded microplastic concentrations of up to 6,500 plastic particles per kilogram of the seafloor; those are extremely high values."
The experiment has been described as a “landmark study” by sea ice physicist at the British Antarctic Survey, Dr. Jeremy Wilkinson. "Microplastic particles were found throughout all cores sampled. It suggests that microplastics are now ubiquitous within the surface waters of the world's ocean. Nowhere is immune."
Dr. Jason Holt of the National Oceanography Centre says: “It is therefore vital to understand the transport and fate of plastic waste in the Arctic and how it impacts on the marine environment there, and what can be done to reduce this impact.”
Recent research conducted at the State University of New York found microplastics in the water bottles of 11 leading brands. The impact of microplastics on human health is currently unknown.
By Joshua Poole
