Searching for life in the Dead Sea: Microbiological study using imaging spectroscopy

The Dead Sea is very harsh environment even for microorganisms adapted to hypersaline environment. Not only does the Dead Sea contain the highest salt concentration of all natural lakes inhabited by living organisms, but the peculiar ionic composition of its water, with its high concentration of divalent cations magnesium and calcium, is highly inhibitory even to those microorganisms that are the most adapted to life in the sea. In this research imaging spectroscopy and microbiological studied used to investigate the spatial distribution of various Archaea populations according to the salty saturation of Mor swamp, Dead Sea Basin. Data from the DLR airborne sensor DAIS-7915 in the spectral range between 0.4 to 2.4 μm were acquired along with field and laboratory spectral measurements. The spatial and spectral data were completed by microbiological analysis. The spectral information helped to detect a concentric distribution of the Archaea population, which seems linked to the state of the salty substrate. In the wet muddy central zone lives an Archaea with the relatively lowest salt tolerance. From this centre to the peripheries, the tolerance to salt of the Archaea population was found to be increasing, as the substation changes from salty pools to salty muds and finally to massive salt layers.