Once a year, scientists Megan Balks and Jackie Aislabie venture to the coldest place on earth, visiting climate research stations in Antarctica.
Since the mid-1990s, Jackie, a microbiologist at Landcare, and Megan, a soil scientist, have been studying old oil spills, to assess the impact of human activity in Antarctica. The conditions in this unique environment mean the decomposition of oil, whether by biodegradation or evaporation, is much slower than in other parts of the world.
Megan and Jackie have to go through special medical and safety training before they can set foot on the icy continent. They also have to get their equipment ready and prepare their research programme.
Jackie and Megan’s backgrounds complement each other. While Megan looks at the soil physics, the ways that the fuel moves through the soil, how fast it moves, and where it ends up, Jackie works on the biodegradation of the fuel by the micro-organisms that are growing in the soil in response to fuel spills.
The two scientists look at factors like nutrients and soil moisture. “Moisture is definitely part of it,” says Megan. “The Antarctic environment is very dry, so when you are studying exposed soil materials, you have to consider that the rate of evaporation is greater than the rate of precipitation
Megan also points out that, during the 24-hour days of the Antarctic summer, the surface of the soil can get quite warm. “We regularly had temperatures up to 20°C on some of the soil surfaces, so for short periods of time, the temperature is quite high. If you are trying to investigate the limitations for microbial activity, temperature may not be the limiting factor.”
Jackie is looking at bacteria in the soil and began by searching for hydrocarbon degraders – bacteria that break down spilt fuels. She found that, where hydrocarbons had been spilled, the soil was enriched with the degraders, but the population numbers were much lower than she would expect to find in New Zealand soil.
The scientists are intrigued about the amount of microbial diversity in Antarctic soils and want to know more about the factors which might affect this diversity – temperature, moisture and nutrients.
An international effort
Having started measuring soil temperature and moisture content, Megan and Jackie were able to draw on the expertise of scientists from other countries, such as the United States and Italy, who have set up testing stations measuring soil temperature and moisture in oil spill sites, as well as three control sites at places with no spills. These climate stations record 69 different sets of data every hour – that adds up to a lot of numbers! – so by now, the researchers have millions of data points.
What have they found?
Scientists have recognised that data from the soil probes is related to the above-ground climate, and that data such as air temperature, humidity, solar radiation, wind speed and direction are really useful in describing the Antarctic environment.
Nature of science
The process of science is often the result of collaboration of a group of scientists. Most research takes too long, is too expensive and needs more knowledge and expertise than an individual scientist working alone. Collaboration with other scientists that have expertise in a particular field or in a particular area of knowledge is essential.
Find out more about Soil Climate Research Stations in Antarctica.