SAEF scientists embark on expedition to study microbial life in the water beneath Antarctica’s Dry Valleys

A team of SAEF microbiologists has departed on a research expedition to the McMurdo Dry Valleys, the largest ice-free desert in Antarctica, to investigate the region’s little-known groundwater system and the unusual microbial life it supports. 

Over the next month, Monash University researchers Dr Ry Holland, Dr Tess Hutchinson and PhD candidate Zachary Galvani, together with University of Waikato scientist Professor Gary Wilson and two Blake Ambassadors, will travel with Antarctica New Zealand to the region’s third-largest valley, Taylor Valley.

Its extremely cold, dry, nutrient poor conditions make it inhospitable for almost all forms of Antarctic life. However, its incredible microbial communities have evolved to survive and thrive in its polar desert soils in surprising and remarkable ways. Many have evolved to “live on air”, drawing energy from trace atmospheric gases such as hydrogen, carbon monoxide and methane. 

“This fascinating process has recently been termed ‘aerotrophy’ and means these microbes have access to an endless energy source: air! This gives them a huge advantage over other microbes that require sunlight, which is only present during Antarctic summer, or nutrients such as organic carbon, which is scarce in this harsh environment,” said Dr Hutchinson. 

In 2015, scientists discovered a groundwater system beneath this dry polar desert and, in 2023, that it is likely contributing to patches of extremely high greenhouse gasses in the overlying soils. This season, a collaborative project will bring together complementary expertise from Monash University and the University of Waikato in microbiology and permafrost processes. The SAEF team will apply their microbiology expertise to uncover, for the first time, how microbes in the soil and groundwater might be interacting to mitigate or amplify the proportion of these gases that escape to the atmosphere. The team also hopes to determine where this ancient, briny water originates from and whether it connects to groundwater systems further inland. 

“The groundwater underneath Taylor Valley has probably been isolated from the surface for millions of years, so on one hand it’s just incredibly interesting to understand how microbial life survives down there, and that could also provide clues to how life might survive elsewhere in the universe,” said Dr Holland. 

The cold, ancient brines may be analogous to subsurface brines on other planets, such as Mars, where water may be found below the surface.  

The team will also be looking to understand how the microbial communities are likely to respond as the climate continues to warm. 

“Previously, the extremely cold temperatures in Antarctica meant that there is a thick layer of permafrost, permanently frozen soil, which acts like a lid containing everything underneath it. But with warming temperatures, this layer can crack or become thinner, letting more of these gases reach the surface. This season, we want to understand what role microbes in the overlying soil might play in this system, to better understand how it will respond to climate change,” said Dr Holland. 

The fieldwork will involve collecting soil and water samples throughout the valley. Back in the lab, the team will conduct the first metagenomic analysis of the microbes in the region, allowing them to identify the traits, such as the ability to survive on hydrogen or produce water, that enable these organisms to survive in such extreme conditions, and to understand the roles they perform within the environment. 

In addition, PhD student Zachary Galvani is investigating how microbial communities form and interact with various microhabitats, such as cryoconite and gas seeps in the ice. 

“Warmer temperatures are resulting in more of these tiny worlds appearing in the Dry Valleys, and overall very few of the studies here have clarified how microbes collaborate or compete for energy acquisition. This expedition will be a wonderful opportunity to look at the specialised life that lives here from a new perspective – something which is very exciting and important as Antarctica continues to evolve under climate change.”

The team will travel with SAEF partner Antarctica New Zealand, flying from Christchurch to Scott Base and then onto the Dry Valleys in late-December. The project is part of a collaborative research partnership between SAEF partners Monash University and the University of Waikato. Follow their expedition via SAEF’s Instagram and LinkedIn.