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Climate change may be priming antarctica for more plastic pollution, invasive species

19 July 2018 | Mitigation

Long believed to be isolated from the rest of the world, oceanic currents could be connecting Antarctica in ways scientists never imagined. Research published in Nature Climate Change shows that when paired with climate change, this interconnectedness could allow for drifting plastics and invasive species to make their way to the continent, altering its environment.

It all started with an out-of-place bundle of bull kelp discovered on an Antarctic beach last year. DNA samples of the kelp indicated one specimen had come from the Kerguelen Islands in the Southern Indian Ocean and another from South Georgia. When factoring in ocean circulation models, the international multidisciplinary team determined that the kelp would have passed through barriers like polar winds and currents once believed to be impenetrable in order to have reached Antarctica.

It’s the longest known “biological rafting event” ever recorded and among the first evidence showing something such as kelp could drift as much as 20,000 kilometers (12,400) to reach the continent, making it the longest known “biological rafting event” ever recorded.

Southern bull kelp (Durvillaea antarctica) like those pictured here floated some 20,000 kilometers to Antarctica. Pi-Lens/Shutterstock

“This study shows that Antarctica is not as biologically isolated as previously thought – by demonstrating that rafting biological material can cross Southern Ocean barriers to reach the shores of Antarctica,” explained study author Jon Waters in a statement. 

The theory holds that if kelp can ride currents to Antarctica’s remote reaches, then so can plastic and other small species known to hitch rides.

“The results suggest that Antarctica won’t be immune from drifting plastics that are increasingly a problem in the world’s marine ecosystems,” said Waters.

It changes the way scientists not only think about oceanography in this part of the world but the science behind ocean drifting in tracking plastics, debris from airplane crashes, and other material floating through the world’s oceans. In the face of a changing climate, this can affect the environment of the entire continent.

Parts of Antarctica are among the fastest warming places on Earth. If plants and animals can float across the ocean, they could establish and colonize the continent once the environment becomes more suitable to them. It means Antarctica is even more vulnerable to the effects of climate change.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research suggests these differences are almost entirely due to environmental extremes, not isolation,” said co-author Ceridwen Fraser.

 

 

Source: IFL Science