Microplastics have been found in the sea ice of Antarctica for the first time. While the levels of microplastics are relatively low, it suggests that even Earth's most remote continent is not immune from the perils of plastic pollution and human-made trash.

Reporting their findings in the journal Marine Pollution Bulletin, scientists from the Institute for Marine and Antarctic Studies at the University of Tasmania in Australia took a deep look at an ice core collected in East Antarctica in 2009. Electron spectroscopy imaging of the melted sea ice revealed it contained 96 microplastic particles – about 12 per liter – from 14 different types of polymer.

The researchers believe this is the first time microplastics have been documented in sea ice samples from Antarctica, although microplastics have previously been found in sea ice in the comparatively bustling Arctic in the Northern Hemisphere. Back in 2018, Norwegian researchers found that everywhere they looked in the Arctic – no matter how remote the location – there were traces of plastic, with certain areas even containing a significant build-up of plastic pollution. The concentrations of microplastic recently found in the Antarctic are slightly lower than those found previously in the Arctic, but this milestone is nonetheless unwelcome. 

“The remoteness of the Southern Ocean has not been enough to protect it from plastic pollution, which is now pervasive across the world’s oceans,” Anna Kelly, lead study author and IMAS student, said in a statement.

So, where is this stuff coming from? Up to 75 percent of the plastics identified were polymers most notably used in maritime industries, indicating they were likely shed from plastic nets and fishing equipment in the Southern Ocean. The researchers note that the microplastic particles are relatively large, suggesting they were released into the environment locally.

“The microplastic polymers in our ice core were larger than those in the Arctic, which may indicate local pollution sources because the plastic has less time to breakdown into smaller fibres than if transported long distances on ocean currents,” explained Kelly.

“Local sources could include clothing and equipment used by tourists and researchers, while the fact that we also identified fibres of varnish and plastics commonly used in the fishing industry suggests a maritime source,” she said.

As for the consequences of this discovery, it’s hard to say. Broadly speaking, scientists know relatively little about the long-term biological effects of microplastics on life. We do know, however, that larger microplastics can be a danger when ingested by animals and it’s becoming increasingly clear that plastics could present a risk to both marine animals and humans as they may contain toxic chemicals like phthalates and bisphenol-A.

As such, the researchers conclude that microplastics in the Antarctic sea ice “may have consequences for Southern Ocean food webs and biogeochemistry.”