Microbial Mats in Antarctica as Models for the Search of Life on the Jovian Moon Europa

Abstract

Cryo-ecosystems dominate cold environments such as the Antarctic and are characterised by persistent cold temperatures with freeze−thaw cycles, extreme light conditions (including ultraviolet radiation) and high variability in nutrient availability and salinity (Vincent, 2007). In Antarctica, freshwater cryo-ecosystems can be found in the form of ice-based habitats such as the meltwater ponds on the McMurdo Ice Shelf (Fig. 1) which contain liquid water during the summer months but completely freeze-over in the winter (Howard-Williams et al., 1990). These systems are dominated by microbial life including complex sustainable cyanobacterial-dominated microbial mat communities. Analogous cryo-ecosystems have also been discovered in the Arctic and have been considered as models for how microorganisms may have survived and evolved during major cooling and freeze-up events on early Earth (Vincent and Howard-Williams, 2000; Vincent et al., 2004a).