It has rained for three consecutive years for the first time in 500 years in the world’s driest desert and the water has devastated the microbes in what was an incredibly rare ecosystem used to surviving without water for 150 million years.
The region is constantly under observation from experts because the extreme dryness is regarded as a good analogue for Mars studies. As with Mars, the soil is extremely poor in organic life and yet it is still inhabited by microbial species from the three domains of life which are both dryness and radiation tolerant, and have lived in the region since the Jurassic period.
The situation in the ‘hyperarid’ heart of the Atacama desert in northern Chile that has seen consecutive rains for the first time in 500 years has shocked scientists, as rather than supporting the development of life in the desert, they say the rain has destroyed it.
The team from the Centre of Astrobiology say that the rain has devastated the microbial species that live there and were accustomed to no rain, according to the study published in Scientific Reports magazine.
The recent rains have been attributed to climate change and investigator Armando Azua-Bustos explained: “Our group has discovered that, contrary to what could be expected intuitively, the contribution of water has not meant a development of life in the Atacama, but on the contrary the rains have caused a huge devastation of the microbial species that lived in these places before the precipitation.
They added: “… the sudden and massive input of water in regions that have remained hyperarid for millions of years is harmful for most of the surface soil microbial species, which are exquisitely adapted to survive with meagre amounts of liquid water, and quickly perish from osmotic shock when water becomes suddenly abundant.”
The study said the indigenous micro-organisms that were perfectly adapted to live in the extremely dry conditions were unable to adapt to the new conditions and 85 percent of microbial life in the areas studied has been destroyed.
The Atacama desert is one of the driest places in the world and is the only true desert to receive less precipitation than the polar deserts.