Water is one of the most important ingredients for life on Earth. The presence or absence of biologically available water determines whether or not life will exist. In Antarctica most water exists as ice and is not available for sustaining life. It is usually only during December and January that temperatures will rise above zero and melt water becomes available (Kennedy, 1993). For this reason Antarctica is regarded as the driest desert in the world (Peck et al., 2006, McKnight et al., 1999).