Data collected on the permanently ice-covered lakes of the McMurdo Dry Valleys (MCM) during the late 1950's as part of the International Geophysical Year (IGY) showed that they were the only year round liquid water environments on the continent. Organisms in the lakes must possess novel physiological strategies that allow them to survive at low temperature and under extended darkness. Subsequent research has now shown that most organisms in the lakes are not just "surviving the extremes" but are actively feeding, growing and reproducing. However, nearly all research on the MCM lakes is restricted to the austral spring and summer when logistical support is provided. The unique aspects of physiological adaptation and metabolic function during the permanently cold and prolonged darkness of the Antarctic winter remain unknown. As part of the "International Polar Year 2007-2008" (IPY), the proposed research will study lakes within the Taylor Valley during the transition to polar night to test the overarching hypothesis that the onset of darkness induces a cascade of physiological changes that alters the functional role of autotrophic and heterotrophic microplankton within the lakes. This overarching theme will be addressed through an interdisciplinary study of selected biological components of the lake ecosystems using genomic and physiological tools to understand not only how individual organisms survive, but how they control ecosystem function during this seasonal transition.
This project is directly relevant to IPY objectives as it addresses a major identified theme (Adaptations to Life in Extreme Cold and Prolonged Darkness) with an international (UK, NZ), multidisciplinary team. The research has substantial broader impacts, as it will add to the body of long-term data accumulated by the MCM LTER and MCM Microbial Observatory projects in a synergistic manner; and it will include three undergraduates, a graduate student and two young female investigators. The project is linked to a highly visible education, outreach and human diversity programs supported by the McMurdo LTER, and initiates new outreach programs, including the Passport to Knowledge program.
