“Aliens in Antarctica” is a hard-to-beat, eye-catching headline. And it’s true; they (outsiders!!!) are slowly taking root in a place long considered the most isolated, and pristine, corner of the planet.
But it’s not what you think.
We’re not talking cellophane-skinned, one-eyed creatures from another universe, but rather much more pedestrian invaders, including bluegrass, springtails, and weeds.
By happenstance, I participated in the research that discovered this growing threat to Antarctica. During a 2008 sailing expedition along the Peninsula, my team and I agreed to be sucked by hoses (vacuumed!) on a regular basis. The detritus collected from our clothing, pockets, cuffs, boots, hair and duffle bags was carefully put into sealed bags and sent off to be dissected by scientists at South Africa’s Stellenbosch University and its Center for Invasion Biology.
That year, 2008, also witnessed the height of visitors to Antarctica by both tourists and scientists—more than 40,000. The goal of the “Aliens in Antarctica” project, initiated by the Antarctic Treaty members, was to gauge just how many different invasive species all these visitors were carrying with them.
“We’re not talking cellophane-skinned, one-eyed creatures from another universe, but rather much more pedestrian invaders, including bluegrass, springtails, and weeds.”
The result of all that hosing and bagging from 1,000 volunteers has recently been reported in the Proceedings of the National Academy of Sciences Journal, which gives the alien invasion a hard number: Based on calculations, that season more than 71,000 seeds were carried ashore (31,732 on tourists, 38,897 on scientists), suggesting that on average every person who visits the remote continent unknowingly carries 9.5 seeds with them.
Formally, the aliens are known as plant propagules—detachable structures, such as seeds. At least four alien grasses have been identified and taken root, a reality one Australian scientist labeled a “substantial threat.”
Visiting humans changing an environment by transporting non-native plants is an old story. In Chile, algae arriving on the boots of fly fishermen have recently killed off entire lakes. The Hudson River, where I live, is choked with water chestnuts, which first showed up clinging to tanker ships arriving from afar. Today in the Galapagos, invasive species of plants outnumber native ones.
Until recently, Antarctica had staved off invasives thanks to its isolation and cold. But as more and more people come to visit, and as temperatures warm around its edges, particularly along the Peninsula where most of the tourists visit, all these hitchhiking invasives have a far better chance of surviving.
The tourists are not the worst culprits; the study puts most of the blame on visiting scientists who pack up their cold-weather gear at season’s end, take it home, use it in a variety of natural settings and then return with it to Antarctica accompanied by undetected stowaways.
Stemming the problem is a challenge. Asking Antarctic visitors to be more dutiful is a start. Visitors should wash boots and vacuum clothes and bags before arriving. In the words of Steven Chown, the invasive biology expert who co-authored the “Aliens in Antarctica” report, “Good biosecurity begins with personal responsibility.”
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This article was posted in Antarctic Treaty, Antarctica.