Of the known alien (non-native) species found inhabiting Antarctica, a non-biting species of midge currently is believed to represent one of the greatest risks to terrestrial ecosystems, researchers have found.
A miniature crawly alien species is slowly invading one of the most isolated continents on Earth, Antarctica, and scientists say that its mere presence poses a great risk to the terrestrial, and fragile ecosystems of the icy continent.
The species, known as Eretmoptera murphyi is a miniature fly-like yet wingless insect native to the nearby sub-Antarctic South Georgia Island.
And while it can’t travel on its own across great distances, scientists have found it on Signy Island, located in the maritime Antarctic. It is believed that the ‘midge’ hitched a ride during plant experiments performed in the 1960s.
Now, scientists from the University of Birmingham and the British Antarctic Survey are studying how the midge is able to survive in extreme polar conditions and what sort of impact it has on the ecosystems of the region. To do so, they collected a plethora of information about the midge, and other invertebrates, microbes, and looked at the water content, organic carbon, soil nitrogen content, and other factors. They then compared the data against other areas where the ‘alien’ species wasn’t found.
On Signy Island, this equates to a three- to four-fold increase relative to areas where the midge is not found.
As noted by the University of Birmingham, the ‘alien species’ feeds on dead organic matter, and with no competitors or predators on the island, the creature can release massive volumes of nutrients into the soil, which in turn will affect peat decomposition and soil structure, thereby having wider impacts on all levels of biodiversity.
“This is concerning as Signy Island hosts some of the best examples of moss banks in the Antarctic region. It is also home to Antarctica’s only two flowering plant species, the hair grass, and pearlwort,” said researcher Jesamine Bartlett, from the University of Birmingham, in a statement.
“Visitors to Antarctica are subject to increasingly strict biosecurity measures but accidental introductions continue to occur,” said Peter Convey of the British Antarctic Survey.
“Midge larvae, for instance, are tiny and cannot be seen easily with the naked eye. Tourists and researchers may be bringing them in from their stopovers in the sub-Antarctic and moving them around the continent in the mud on their boots.”