There's concern floating plastic in the world's oceans could one day be a threat to wildlife in Antarctica.
Researchers from University of Otago are rethinking their views on ocean drift after some unusual clumps of seaweed were discovered on an Antarctic beach. Antarctica is one of the world's most unspoilt locations.
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Scientists have long believed the continent was protected by the Roaring Forties winds, and the world's strongest ocean currents.
"We thought Antarctica was isolated, that there are these barriers out there in the ocean, almost like a brick wall - and stuff couldn't get across. So we thought Antarctica is isolated ecology," University of Otago zoology department Professor Jon Waters says.
That view's now changing, after unusual clumps of bull kelp were found washed up near the Antarctic Peninsula.
Dr Ceridwen Fraser and a team from University of Otago used genetic tests to trace the seaweed's origin right back to islands in the Southern Indian Ocean.
"The journeys that these kelps must have taken were about 20,000 kilometres, which is a world record for how long we know stuff to have travelled at sea,"Mr Waters says.
Storms driving floating objects across the ocean's barriers could change marine ecosystems. It could also bring more unwanted debris like microplastics already found in Antarctic waters.
The research suggests there is a viable pathway for floating plastic patches from the South Atlantic and South Pacific to one day reach the icy continent.
"There's a real sense now that Antarctica is not immune from plastics," Mr Waters says.
"The plastics that are accumulating around the world, there's a real sense that they might be showing up more and more in Antarctic waters."
The research will create a better understanding of how the world's oceans are connected.
It'll also change the way scientists calculate the journeys of floating objects from plastic garbage through to aeroplane crash debris.