Captain’s Log No. 3 – A Tale of Survival

November 11-14, 2008

Science is now going full steam in the altiplano (no pun intended for Lascar). When I look at this team and the expertise present, it is clear that this year represents the most integrated science in the field. This is not surprising as the project has matured and our objectives are clearer. The central objective is still to understand how increased UV impacts life and along this six year journey: geologists, geophysicists, microbiologists, limnologists, and UV ecologists have joined the High Lakes Project. This year, all these disciplines are represented. This is the most unique and the greatest strength of Astrobiology. Each of these team members brings their own perspective, and when combined, they offer a more profound vision to our question.

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First day in the field – Nathalie pointing to Laguna Lejia

So many lakes and so little time and for “Cookie” (Ingrid), our fearless geologist, so many volcanoes, so little time. She tells us about the history of the parent-rocks of the sediments we collect in the lakes, their changes through time, sometimes about the fury of the volcanoes which entombs life in the lakes for decades after an eruption. This is the case for Laguna Lejia, too close to the volcano Lascar for comfort. The ecosystem in the lake is barely recovering from the last eruption of 1993.

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Ingrid studying the stratigraphy of Laguna Lejia’s ancient terraces

Erich and Eric, one from Ames and one from UCN Antofagasta, along with Lee, also from Ames, investigate the lakes in search of clues about microbial life, its adaptation – or lack thereof- to UV 170% higher than sea level, ozone level below ozone hole definition (40% depletion) for 36 days per year on average and between 25-35% depletion the rest of the year. Temperature daily variability can reach 50 degrees Celsius, aridity averages 30% but values around 10% are far from rare. An almost exclusively volcanic and lacustrine environment gives our sites an air of early Mars or early Earth.


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Laguna Aguas Calientes with Simbad and Pili Volcanoes in the background

Understanding how life survives here provides clues not only to document the question of life and its survival potential on Mars in the past but also points toward our own past, our own journey from a time when life on Earth was barely hanging, a fragile miracle in an adverse environment of no ozone and constant impact bombardment to today, when life has become complex and advanced enough that it starts asking questions about its own origin.

How does climate variability affect habitability and diversity? What kind of changes does it trigger and how fast? Kevin, Jeremy, Edmond and myself are trying to document this point, Edmond and I by documenting the geophysical and meteorological environment, assisted by Jutson, Kevin and Jeremy by looking at the consequences of climate variability in the water column.

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Team at work at Aguas Calientes. From r to l: Jeremy, Kevin, Nathalie, Erich & Eric

We have seen the chemistry of these lakes change yearly in a significant fashion for the past 6 years. Still, life keeps up, at least so far. We do not have the data yet to tell how life’s diversity is affected by this variability. What we observe is that life is present and some species have very dense populations, such as some species of zooplankton and many species of algae. They seem, to all of us, to have presented adaptation strategies against UV, some totally counter-intuitive. They hold important clues for our past and our future, and that of other planets. Tirelessly, we sample, analyze, question, and sample again in an infinite spiral that gathers knowledge along the way and raises even more questions.

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Microbial mat at Aguas Calientes

In the process, we become more integrated into a unique landscape that little by little reveals other wonders as important as our quest, still talking about life’s survival and perpetuation. Three days ago, as we arrived on the shores of Laguna Aguas Calientes for a full day of science there, we witnessed a unique spectacle, unfortunately so foreign to the city dwellers we all are. Our pick-up trucks stopped about 50 meters away from two ñandus, probably two females which ran away into the hills as we approached. We soon realized that while running, they had left behind a little crew of 13 chicks led by the inevitable fearless little leader. They were obviously distressed by the disappearance of their moms and the presence of these strange creatures, two-legged ones just like them but with no feathers (expect maybe for Edmond’s down jacket). They were about 40 cm high, with dark and grey feathers and running everywhere. We left them behind with regret but decided not to disturbed them anymore.

We reached the shore of the lake where we started to prepare for sampling, donning waders, grabbing our plankton nets and our sample bottles, our multi-parameter meter to analyze the water chemistry and the radiometer to analyze UV. Then, something totally unexpected happened. The little guys, all 13 of them, showed up on the shore and went right for Macario, our guide. I do not know if this happened because Macario was wearing a sweater which its dark color could have reminded them of their moms. Anyway, here is Macario at the head of a 13-strong crew, whistling them back towards land and as on cue, the feathered team started to follow him…Priceless! They finally decided to stay far away from the water. During the day, we could see the moms higher in the hills observing us. They must have come back to claim their little gang after we left because when we came back two days later, moms and chicks were nowhere to be seen.

This little gang represents another face of the tale of life’s survival. They are still fragile but resilient and resourceful. They may err along the way but they have already in them this force to prevail no matter what and they give us a message of hope for the future of our planet.

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Fearless baby ñandus in the vast Altiplano, Chiliques Volcano in the background

Good night from up high,
Nath