Don't Eat the Natives
Taste of Life in a Dry Valley
11 , 2002
is little to smell or taste when hiking through the Dry Valleys
of Antarctica. The air, water, ice and rock give off few molecules
detectable by the human taste buds or nose. But, lack of smell
or taste in water does not mean that it is safe to drink,
as the men in Scott's expedition discovered when they drank
the water of Lake Chad in the Taylor Dry Valley. This is the
story of how they came to name this lake, as told to me by
Dr. John Priscu, and expert on the native life in the Dry
Hoare is down the valley from Lake Chad. The water bottle
I had with me was filled with water pumped and filtered from
Lake Hoare, water that tasted clean cool and refreshing. Lake
Chad probably tasted just as good to Scott's men.
as I walked along the shore of lake Chad, I spotted something
very strange; a pile of brown stuff about the size and thickness
of a cow patty. It was wet, brown and had thin fibrous layers.
I had hiked for days in the Dry Valleys and seen no life,
and yet this looked like a living mass. After I returned to
McMurdo, I showed a picture of the brown mass to Dr. Priscu,
and he immediately identified it as cyanobacteria. He said
that the brown coloration was pigment to protect it against
ultraviolet light, and that it made antifreeze to give it
some protection against freezing and also released toxins
into the lake water.
at the image, I felt as If I had traveled back in time a billion
years to witness the origin of life on earth. This lump of
brown sitting on the wet ground of the Antarctic was, to the
human eye, the apparent ruler of this domain. Not even a single
blade of grass added greenery to this landscape.
and his men ingested the cyanobacterial toxins along with
the lake water. It gave them diarrhea and caused them to use
vast quantities of toilet paper. The brand name of the toilet
paper was Chad, and so, the lake acquired a name.
lesson that you cannot tell the safety of a water supply by
smell or taste is a good one that applies just as much in
California as it does in Antarctica. But there is so little
life in Antarctica that an undrinkable lake is a rare surprise.