For the last 18 months Alyce H and I (Sarah P) have been known as the lake sampling team. We have been working at Davis on Professor Rick Cavicchioli’s project titled: Monitoring Ecosystem Stability in Model Marine-Derived Antarctic Lake (and near-shore) Systems. This expedition builds on two previous summer expeditions (2006 and 2008), and the aims were to:
- Monitor the microbial communities within lakes across an entire yearly cycle
- Develop a further understanding of the microbial communities both within and between years
- Predict how the communities within the lakes will respond to ecosystem change
- Develop a new level of understanding about:
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- molecular mechanisms behind growth, adaptation and survival of microbes
- interactions, gene exchange and evolution of microbial communities
In practice for Alyce and I here in Antarctica, this has involved collecting and filtering water throughout the summer-winter-summer, in all conditions.
The focus of our studies has been on three saline lakes — Ace Lake, Organic Lake and Deep Lake -and a marine site off Davis.
During our time we have sampled Ace Lake nine times, Organic Lake seven times, Deep Lake six times and the marine site three times. These sampling trips came in a variety of forms, ranging from a simple helicopter trip to bring water back to station for filtering, to towing a mobile work shelter and setting up the filtering gear on the lake ice for a few days, and man hauling 200 litres of water one kilometre uphill in knee deep snow (thanks again guys).
After collection (or when set up on the ice in the mobile work shelter) we filtered this water to collect the microbes within it. Each time we visited a site we collected between 70 and 400 samples (depending on how many depths were sampled at each lake). These included filtered biomass, and water samples ranging between one millilitre and one litre.
On top of our main sampling regime, we also took a one-off small sample from another 85 lakes around the Vestfold Hills and Rauer Islands. The majority of these were accessed by walking and filtering one to two litres of water at the lake.
This has been a very rewarding expedition, during which we had to overcome many challenges associated with working in the isolation, extreme cold and changing conditions.
We would like to thank everyone from Davis station, across the summer 2013/14, winter 2014, and summer 2014/15 for all their help. It is appreciated very much.
Sarah P