Marine Biology Seminar: Dr. Scott Perl (NASA Jet Propulsion Laboratory)
"Halophilic Microorganism Preservation using Evaporite Mineralogy within Closed-Basin Lake Systems"
Abstract: Terrestrial closed-basin lake systems tend to have salinities that are significantly greater than marine and oceanic environments. Minerals precipitated within these systems can preserve halophilic microorganisms within crystal matrices and capture micron-scale fragments of the present or former ecology from modern or ancient lake systems, respectively. Moreover, these systems can be maintained over geologic time and in buried cases, provide ample protection from solar radiation. Extant halophilic microorganisms can also modify the mineral-microbial record and even after desiccation, can yield evidence of former habitats, gene expressions, microbial community diversity, and relative dating and duration of habitability due to the longevity of the mineral matrix. I will discuss closed-basin lake systems on Earth where previous and current in-situ campaigns are taking place, ongoing geobiological laboratory analyses that contribute to constraining the halophilic preservation timeline, and upcoming investigations that continue these efforts. Finally, I will discuss how these systems are direct analogues for ancient Martian paleolakes and hydrated mineral datasets that refine the duration of stable water on Mars with implications for the ecologies there should life have ever independently originated on our nearest neighbor.