The British Antarctic Survey (BAS) has recently reported that a tiny flightless midge, known as Eretmoptera murphyi, is causing significant shifts in the soil composition of Signy Island in Antarctica. This small insect is not native to the island but has rapidly proliferated and reshaped the island’s ecosystem and the survival of other species.
Understanding Eretmoptera Murphyi
Eretmoptera Murphyi is a species native to South Georgia, an island in the sub-Antarctic region. The insect found its way to Signy Island in the 1960s due to an accidental introduction during a botany experiment and their rampant spread was noticed in the1980s. Being a type of midge, this tiny insect relies on dead organic matter for sustenance which in turn accelerates the process of plant decomposition. This process has increased soil nitrate levels by three-five times in areas where the insect is present compared to parts of the island inhabited only by native invertebrates.
Nitrate Levels and their Effect on the Ecosystem
Excessive nitrate levels in the soil can be harmful for other plant species and have the potential to contaminate groundwater sources. High nitrate levels disrupt aquatic ecosystems by promoting excessive algae growth. This growth can result in oxygen depletion, jeopardizing aquatic life in these ecosystems.
Spread of the Midge: A Human Induced Problem
Scientists attribute the spread of Eretmoptera Murphyi in Antarctica to human activity, specifically to people potentially carrying these insects on their shoes. The implication of this observation is serious, as it points out human-induced changes to delicate ecosystems that would otherwise remain isolated.
Survival Prowess and Potential Threats
The midge’s ability to survive in water raises the possibility of this invasive species spreading to other islands. This is a source of major concern as the bug has already occupied a larger area than expected and the populations are increasing. The unique Antarctic ecosystem, already vulnerable to climate change, is at risk from these invasive species.
Threats to the Antarctic Ecosystem
Despite Antarctica’s harsh conditions, the midge invasion demonstrates that the continent is not protected from invasive species. There are fears that the activities of the midges, coupled with climate change, will pave the way for other invasive species to establish themselves in Antarctica. This could accelerate the negative effects of climate change on the already vulnerable Antarctic ecosystem.
