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Exploring cyanobacterial diversity in Antarctica Blog

3 Posts tagged with the diving tag
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Diving in Lake Fryxell

Posted by Anne D Jungblut Nov 27, 2012

As I wrote previously, all our microbial mat samples are collected by the divers in our team. AND the divers are back in the water! The diving is happening through a hole in the ice. It takes several days to make the hole. First a smaller hole is drilled and then a coil called a hot finger is used to widen the hole to ca 1 m in diameter.

 

We are not only collecting benthic cyanobacterial mat samples, but the divers are also collecting water from above the microbial mats for nutrient analysis and to determine oxygen concentration, as well as measuring the light conditions under the ice.

 

The scientific diving at Lake Fryxell is done with surface supplied air and there are always several dive tenders at each dive. Their responsibilities include tendering to the tethered diver or operating the console for the air supply and communication between the tender and diver.

 

We are getting ready for a dive

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My job is dive tender

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It is the end of a dive and we are getting the diver out of the water

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Full face mask diving set-up

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The objectives of our project are to study the cyanobacterial mats and microbial structures in Lake Joyce to better understand the diversity and processes that create these microbial structures.

 

In order to study the structures the samples need to be collected by  diving. Once they are brought back to our field lab directly on the ice of Lake Joyce, they are documented, the diversity studied using microscopy and samples preserved for further analysis back at our home institutions. I am particularly interested in collecting material for DNA-based tools to study cyanobacterial diversity.

 

 

Diving in Lake Joyce

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Microscopy analysis of cyanobacteria from Lake Joyce

 

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Filtration of water samples

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Lake Joyce, Antarctica

Posted by Anne D Jungblut Dec 4, 2010

Lake Joyce is in the Pearse Valley, a westward extension of the Taylor Valley next to the Taylor Glacier and fed by the meltwater of the glacier. Lake Joyce is one of the smaller Dry Valley lakes. It is perennially ice-covered and the ice is about five meters thick and the ice is not smooth as known from lakes in Europe. The ice is rugged due to irregular freeze-thawing of the top-layer of the ice and deposition of soil from the surrounding hills by the wind.

 

 

Lake Joyce and Taylor Glacier with research tents

 

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Lake ice

 

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Research tents on Lake Joyce ice

 

As the lake is ice-covered samples are collected through diving. The diving is done by three members of our team that are very experienced scientific divers. In order to directly process our samples we had two tents on the ice next to the dive hole.

 

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