The tiniest of invaders have been entering Antarctica and could alter an ecosystem that has been isolated for eons. The invasive species is a non-biting midge, Eretmoptera murphyi, that is very likely brought in via mud on the soles of people’s boots.
The number of people visiting Antarctica, scientists as well as tourists, has grown greatly in recent years. About 5,000 scientific staff and 30,000 tourists now visit Antarctica every year.
At the recent annual meeting of the British Ecological Society, Peter Convey of the British Antarctic Survey explained how the tiny flies have found their way to a new ecosystem after centuries on centuries. People traveling to Antarctica first stop on South Georgia Island in sub-Antarctica which is on its own tectonic plate. This plate, Convey explains to the BBC, has been moving away from South America for 30 to 40 million years. Antarctica is on a different tectonic plate “and there are things on there that have got a similar multi-million, if not multi-tens of million-year histories.”
The midges, which can survive in extreme conditions, are changing conditions for native species in Antarctica by releasing nutrients into the soil at a heightened rate, Convey explains:
“In terms of function, their job is litter turnover – they help things decay in the soil – and the population density of this thing in the area where it has been introduced is responsible for more litter turnover than the community that was already there.”
“So basically it is bringing a function into an ecosystem that is not very active already. In principle, it can be a fundamental change in the way that ecosystem works.”
The flies could even “drive locally or generally extinct some of the unique species that already exist in part of the Antarctic,” Convey emphasizes, as well as that ”If we are not careful about the way we move around then we could be a very good carrying vector.”
The flies are actually being carried all the way to the tip of the Antarctic peninsula, when people visit the ice-covered, mountainous Elephant Island.
In archaeology, it is said that to excavate something is both to make it possible for us humans to study it, and to destroy it. An artifact, from a coin to an arrowhead to the remains of an ancient house, have all been preserved for years in the soil; contact with oxygen means the site is exposed to a whole new range of elements it had been protected from.
Something analogous is now occurring in the no longer isolated, fragile ecosystem of Antarctica, exposed to a whole new world of creatures (humans, midges) who could be wreaking potential, irreversible havoc.
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