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Investigating the Impact of UV Radiation on High-Altitude Shallow Lake Habitats, Life Diversity, and Life Survival Strategies: Clues for Mars' Past Habitability Potential?We present data and results from an ongoing project of astrobiological high-altitude expeditions investigating the highest and least explored perennial lakes on Earth in the Bolivian and Chilean Andes, including several volcanic crater lakes nearing and beyond 6,000 m in elevation. In the next five years, they will provide the first integrated long-term astrobiological characterization and monitoring of lacustrine environments and their biology for such altitude. These extreme lakes are natural laboratories. They provide the field data missing beyond 4,000 m to complete our understanding of terrestrial lakes and biota. Research on the effects of UV has been performed in lower altitude lakes and models of UV flux over time are being developed. Lakes showing a high content of dissolved organic material (DOM) shield organisms from UV. DOM acts as a natural sunscreen as it influences the water transparency, therefore is a determinant of photic zone depth. In sparsely vegetated alpine areas, lakes are clearer and offer less protection from UV to organisms living in the water. Transparent water and high UV irradiance may maximize the penetration and effect of UV radiation. Shallow-water communities in these lakes are particularly sensitive to UV radiation. The periphyton can live on various susbtrates. While on rocks, it includes immobile species that cannot seek low UV refuges unlike sediment-dwelling periphyton or alpine phytoflagellates which undergo vertical migration. Inhibition of algal photosynthesis by UV radiation has been documented in laboratory and showed that phytoplankton production is reduced by formation of nucleic acid lesions or production of peroxides and free oxygen radicals. of peroxides and free oxygen radicals. Our project is providing the field data that is missing from natural laboratories beyond 4,000 m and will complement the vision of the effects of UV on life and its adaptation modes (or lack thereof).
Document ID
20040065942
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Cabrol, A.
(NASA Ames Research Center Moffett Field, CA, United States)
Grin, E. A.
(NASA Ames Research Center Moffett Field, CA, United States)
Hock, A.
(NASA Ames Research Center Moffett Field, CA, United States)
Kiss, A.
(Budapest Univ. of Technology and Economics Budapest, Hungary)
Borics, G.
(Trans-Tiszanian Reg. Hungary)
Kiss, K.
(Hungarian Academy of Sciences Hungary)
Acs, E.
(Hungarian Academy of Sciences Hungary)
Kovacs, G.
(NASA Ames Research Center Moffett Field, CA, United States)
Chong, G.
(Universidad Catolica del Norte Coquimbo, Chile)
Demergasso, C.
(Universidad Catolica del Norte Coquimbo, Chile)
Date Acquired
August 21, 2013
Publication Date
January 1, 2004
Publication Information
Publication: Lunar and Planetary Science XXXV: Astrobiology Stew: Pinch of Microbes, Smidgen of UV, Touch of Organics, and Dash of Meteorites
Subject Category
Lunar And Planetary Science And Exploration
Distribution Limits
Public
Copyright
Public Use Permitted.
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