A Herman Nelson heater provides warmth in the lake water sampling tent on Lake Bonney. John Priscu, Montana State University, and his research team, study lakes in Taylor Valley during the transition to polar night, testing the hypothesis that the onset of darkness induces physiological changes in microplankton. The researchers studied biological components of the lakes using genomic and physiological tools to understand not only how individual organisms survive, but how they control ecosystem function during this seasonal transition.