Lakes are calm and dark, for now.
Even the lakes in Antarctica contain lots of separate and different habitats. Imagine what it’s like under a permanent cover of ice: some sunlight gets through, but the water gets darker and colder the deeper you go. It’s very still. There are different conditions—distinct chemistry, even—depending on the depth. So, of course, the organisms that grow at each depth differ, too.
Now imagine more and warmer water spilling into the lakes in summer from the melting glaciers and streams higher up the valleys. This increased flow teems with organisms and nutrients from everywhere else in the landscape. The ice thins, more light penetrates, water starts moving around. Eventually, the lake’s ecosystem has fewer diverse pockets.
A big part of the research in the Dry Valleys lakes is focused on the environmental adaptations that allow microorganisms to thrive in extreme habitats. The permanently low temperature lakes represent some of the most poorly understood “extreme” habitats in the world, despite the extraordinary biological diversity and global importance of these regions. We are working to understand: what is the physiology of the organisms that call the lakes home? What kinds of genes and proteins allow them to survive and thrive where they do? What species live in which parts of the lakes and why?
Photo: Dr. Rachael Morgan-Kiss collects water from a large ice-free “moat” in Lake Fryxell which forms during the short summer. (Rachael Morgan-Kiss / NSF)