Invasive plant species introduced by visitors and scientists

Antarctica is no longer one of the “most pristine environments on earth.” Visitors are introducing invasive plant species alien to Antarctica at a much higher level, says a study published today (March 6) in the Proceedings of the National Academy of Sciences. It is based on a continent-wide risk assessment undertaken there.

Of all the regions in Antarctica, it is in the Antarctic Peninsula, the Ross Sea region and several landing places in East Antarctica where alien plant seed introduction has been the highest.

‘Primary causes'

Introduction of species not normally found in a region is one of the “primary causes of biodiversity change globally,” says the study.

The seeds were introduced by visitors — scientists and tourists. Though nearly 33,000 tourists visited the ice continent every year as against 7,000 scientists, the latter carried more seeds, the study found.

In all, the visitors introduced about 9.5 seeds per person during the International Polar Year's first season (2007-2008).

Apparently, tourists brought in 31,732 plant species seeds, while scientists carried 38,897 during the study period, say the authors.

In all, 2,686 seeds were collected from people landing on the ice continent. The scientists traced 88 per cent of the seeds to the family level and 43 per cent to the species level.

What makes the study all the more important is the fact that the authors have traced the origin of the seeds to the sub-Antarctic or Arctic regions.

The numbers are staggering — 49 to 61 per cent of seeds are “capable of surviving the conditions likely to be encountered” in Antarctica.

The introduction of such high numbers became possible as people who landed on the continent had travelled to other cold regions like the alpine, the cold temperate and Polar regions a year prior to their Antarctica visit.

This article has been corrected for a grammatical error

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