Microplastics, such as those used in commercial fishing, have been discovered in Antarctic sea ice in what researchers say is a first.
The study, led by an Institute for Marine and Antarctic Studies team, found 96 microplastic particles in an ice core collected from the frozen continent's east in 2009.
Lead author Anna Kelly says plastic pollution had previously been recorded in Antarctic waters and sediments but never in sea ice.
"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," Ms Kelly said.
The ice core, made of coastal land-fast sea ice, contained 14 different types of polymer, or plastic, and averaged almost 12 particles of microplastic per litre.
Ms Kelly said the particles were larger than those found in ice in the northern hemisphere's Arctic and may indicate local pollution rather than transportation via ocean currents.
"Local sources could include clothing and equipment used by tourists and researchers," she said.
"The fact that we also identified fibres of varnish and plastics commonly used in the fishing industry suggests a maritime source."
The presence of microplastics in the ice keeps them for longer near the sea surface, Ms Kelly said, making them more likely to be eaten by organisms such as krill.
Formed from seawater, around 80 per cent of Antarctica's sea ice melts and re-forms each year.
"It is worth noting that plastic contamination of west Antarctic sea ice may be even greater than in our ice core from the east as the Antarctic peninsula hosts the bulk of the continent's tourism, research stations and marine traffic," Ms Kelly said.
The research was published in a May edition of scientific journal Marine Pollution Bulletin.
Australian Associated Press