The common house fly might not be a problem in towns and cities in North America. Sure, they’re a little pesky, but we wouldn’t consider them invaders or contaminators. Unfortunately, in a pristine and vulnerable environment like Antarctica, it’s not the same story. With the introduction of new species, like the common house fly, conservation efforts in Antarctica are increasingly put at risk.
How Do the Flies Get to Antarctica?
Flies and other similar invasive species generally arrive in Antarctica via ship. They thrive in the kitchens on board and then make a new home in Antarctica once the ship docks. As the environment in Antarctica begins to warm, flies and other species find it easier to survive on land.
These invasive species generally carry pathogens that native Antarctic lifeforms cannot survive. There are several indigenous insects, mosses and lichens native to Antarctica that are now at risk. Thus, a seemingly harmless house fly becomes a killer when exposed to native plants, animals and insects that are not used to interacting with flies.
How Do the Flies Survive in Antarctica?
On coastal areas near the south pole, temperatures have risen more than 3 degrees Celsius over the last 30 years. These warm areas are the perfect breeding ground for invasive species in the form of larvae and seeds. The increase in temperature also causes glaciers to retreat, which means there is more exposed land that plants and animals can colonize. For example, the vulnerable Antarctic peninsula has become home to a quick growing thick moss. The moss, an invasive species in itself, is also the perfect setting for other new species to take hold.
The Problem with Tourists and Researchers
Visiting researchers and tourists are one of the biggest threats to Antarctica’s native species of plants, animals and insects. In the 2015-2016 tourist season, more than 38,000 tourists visited Antarctica. That number was expected to increase to 43,000 tourists in the 2016-2017 season.
Dominic Hodgson of the British Antarctic Survey explains that while the tourists don’t mean to cause a problem, it’s hard to be 100% safe. He says, “These tourists are often very scrupulous about not leaving waste or having mud – which could carry seeds or bugs from other areas – on their boots when they set foot on the Antarctic peninsula. However, it is still very difficult to avoid contamination. Camera bags are a particular problem. People take them from one continent to the next and rarely clean them. They put them on the ground and seeds picked up elsewhere get shaken loose. It is a real issue.”
The Problem with Climate Change
Despite the issues of contamination with tourists and researchers, Hodgson and his colleagues recognize that the real problem isn’t with Antarctica’s visitors, it’s with climate change. Global warming is making Antarctica a warmer and greener space. The peninsula has been rising in temperature since temperature data was first collected in the areas in the 1950s.
With rising temperatures, Antarctica’s native plant life has reacted dramatically. The native plants in Antarctica only cover 0.3% of the continent, so any response to an invasive species could spell the end of a native species.
British researcher Dan Charman from Exeter University studied moss banks in Antarctica. He found that the non-native moss was growing 4-5 times faster than it was in 1950. Charman explains, “The sensitivity of moss growth to past temperature rises suggests that ecosystems will alter rapidly under future warming, leading to major changes in the biology and landscape of the region. In short, we could see Antarctic greening to parallel well-established observations in the Arctic.”
How Can We Fix This Problem?
Current biosecurity to control invasive species in Antarctica, according to Kevin Hughes of the British Antarctic Survey, is inadequate. Invasive species are still coming onto the continent and contaminating the environment and native species before they can be efficiently removed.
The British Antarctic Survey calls for better education for tourists and scientists visiting Antarctica. All visitors should understand the importance of conservation and very real threat of contamination. The group also calls for contingency plans to be put into place to deal with invasive plant and animal species based on the knowledge of scientific experts.
Hodgson sums up the survey with a warning, “The insects and plants that are native to Antarctica have survived there for thousands of years. We have got to act now if we want to save this last, pristine environment.”