{"id":5933,"date":"2017-11-30T13:12:35","date_gmt":"2017-11-30T08:12:35","guid":{"rendered":"http:\/\/www.cawater-info.net\/all_about_water\/en\/?p=5933"},"modified":"2017-11-30T13:01:41","modified_gmt":"2017-11-30T08:01:41","slug":"scientists-and-tourists-bring-thousands-of-alien-seeds-into-antarctica","status":"publish","type":"post","link":"http:\/\/www.cawater-info.net\/all_about_water\/en\/?p=5933","title":{"rendered":"Scientists and tourists bring thousands of alien seeds into Antarctica"},"content":{"rendered":"

Aliens are invading Antarctica. Thanks largely to scientists, they have already established a foothold on the frozen continent, and their numbers are set to increase. This might sound like the plot of John Carpenter\u2019s classic film\u00a0The Thing,\u00a0but it is very real.<\/em><\/p>\n

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The aliens in question are not body-snatching monsters, but plants from other parts of the world.\u00a0Steven Chown\u00a0from Stellenbosch University found that in just one summer, visitors unwittingly imported around 70,000 seeds to Antarctica. And even though the continent has a reputation for being harsh and desolate, many of these immigrants have already founded populations in their new homes.<\/p>\n

This is a new chapter in an old story. Wherever humans go, seeds hitch a lift on our clothes and belongings. If these foreigners germinate where they don\u2019t belong, they can often out-compete native plants and uproot local ecosystems. From Japanese knotweed to kudzu vines, these\u00a0invasive species\u00a0cause problems throughout the world. Inhospitable though Antarctica is, it\u2019s not immune to such invasions. It does, however, present a valuable opportunity to study them.<\/p>\n

In most cases, we can only see the results of plant invasions when it\u2019s too late. We know that many species are brought into new places accidentally, but it\u2019s hard to quantify how often this happens. You can hardly stop everyone entering a country and count the number of seeds that they\u2019re carrying. Except when you can. Travel to Antarctica is so limited that Chown managed to stop 2 per cent of all the visitors in a single summer and count the number of seeds on their persons and belongings.<\/p>\n

Around 850 people \u2013 scientists, tourists, support personnel, and ships\u2019 crew \u2013 submitted their clothes, equipment, shoes and bags for inspection. Chown\u2019s team ran a vacuum cleaner over everything and sorted through the accumulated fluff by eye. Extrapolating their sample to the total number of Antarctic visitors, they estimated that 70,000 seeds are brought into the continent each year.<\/p>\n

They also found, perhaps surprisingly, that scientists were a bigger problem than the tourists. Even though they should be most aware of the problem of invasive species, around 7,000 of them brought in around 39,000 seeds. By comparison, 33,000 tourists imported just 32,000 seeds. \u201cScientists tend to have gear they use more than once and tend also to visit many natural sites,\u201d Chown explains. \u201cOften tourists are issued with new outer gear for a visit or make only a single visit to Antarctica and have special gear for the trip.\u201d<\/p>\n

The team managed to identify most of the seeds that they found. The list included many familiar faces, including species that have invaded other cold areas like the Arctic and the islands around Antarctica. You might think that foreign plants would have a tough time surviving in such frozen wastes, but that\u2019s not the case. Chown found half of the visitors he surveyed had previously travelled to cold parts of the world, including other high mountains and other polar regions. And at least half of the seeds they brought in came from those environments. They were already primed for their new home.<\/p>\n

By mapping the entry points for seeds, and matching these to the local climate, Chown produced a map of Antarctica that shows where invaders are most likely to gain a foothold. The Western Antarctic Peninsula \u2013 the continent\u2019s sinuous tail \u2013 is the area of greatest risk.<\/p>\n

There have been signs of these problems for years. For example, annual bluegrass, an important invasive species, has already spread from outlying islands to several stations in the western peninsula. But Chown\u2019s study is the first comprehensive assessment of the risk that Antarctica faces from invasive plants.<\/p>\n

Antarctica is harsh and cold, yes, but also relatively pristine. It has its\u00a0own collection of flora and fauna that have adapted to life in this toughest of environments. They could be displaced by invaders, especially since more and more people are visiting, and parts of the continent are losing their ice in the face of climate change.<\/p>\n

Fortunately, Chown thinks that there are simple ways of holding back future invasions. \u201cTake gear that\u2019s new,\u201d he advises, \u201cand if this is not possible, then clean gear thoroughly. Vacuum clean the pockets, check Velcro very closely and remove seeds. Remove inner linings from camera bags and clean everything out. Wash walking poles, tripods and boots \u2013 easy and very effective. Cargo in pallets is harder, but a good hot wash does wonders.\u201d<\/p>\n

Source:\u00a0http:\/\/phenomena.nationalgeographic.com\/<\/a><\/p>\n

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