So why are we here?

Taylor Valley Via Wikimedia Commons

Being here is exciting and amazing, but I’m not here to have an adventure (that’s just a bonus).  We’re here to study the microbiology in the Dry Valleys, a region in Coastal Antarctica.  The Dry Valleys are a network of valleys in coastal Antarctica, about 50 miles from my current location in McMurdo Station.

Like most of Antarctica, the Dry Valleys are a desert, although unlike the vast majority of the continent, they are not covered in ice.  In fact they are the largest region not iced over, covering about 1,900 square miles or 0.03 percent of the landmass.  Cold, dry air blows down from the mountains, and prevents precipitation.  Any snow that does fall sublimates into water vapor before there is time for it to accumulate.

Landsat 7 satellite image Via Wikimedia Commons

The only water sources to the Valleys are streams.  During the summer, the glaciers surrounding the region melt a bit, and the meltwater flows through the valley floors.  These rivers support a unique micro-ecology.  The major vegetation in the dry valleys is microbial mats. Primarily composed of the prokaryotic algae Nostoc commune, they go dormant during the dry winter and burst to life as soon as the water begins to flow. 

Nostoc commune forms, via Wikimedia Commons
left - multicellular thallus (simple plant body)
right - microscopic trichomes (filaments)

Nostoc is photosynthetic and can convert nitrogen from the air into ammonium, an important nutrient.  Therefore, the algae supports a diverse ecosystem, composed mostly of bacteria, along with some protists, like nematodes and tardigrades.  The organisms have some interesting physiologies, and are well suited to the extreme conditions.  Enzymes found in these organisms may be commercially useful, to do things like catalyzing polymerase chain reactions (PCR) at low temperatures.

There's a much cooler rationale for our research here.  The valleys are similar in climate and geology to what we may find on Mars, and the organisms living there may be similar to what once lived on the red planet.

-Andrew