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Exploring cyanobacterial diversity in Antarctica Blog

2 Posts tagged with the leptolyngbya tag
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Today we went to an area that is classified as Antarctic Specially Protected Area or ASPA. These are sites that are of special historic or ecological significance and a permit is required for entry.

 

The area comprises sloping ice-free ground with summer ponds and small meltwater streams draining from the Canada Glacier to Lake Fryxell. It is  is on the other side of the Canada Glacier and  the hike took ca 1.5 hours including the crossing of Canada Glacier.

 

                                                                             Canada_glacier.jpg                                             

 

 

The Canada Glacier stream area has high biomass accumulations in comparison to most other regions of the Dry Valleys. Several moss species (Bryum argenteum, Hennediella heimii and Bryum pseudotriquetrum), lichens (Lecanora expectans, Caloplaca citrina) and freshwater algae (Prasiola calophylla, Tribonema elegans) have been described from the stream area (Management Plan for Antarctic Specially Protected Area No. 131).

 

         

                                                                                                      Canada stream and Lake Fryxell

                                                                                stream.jpg

 

 

Cyanobacterial mats are also abundant. Oscillatoria, Leptolyngbya, Phormidium, Calothrix, Nostoc and Gloeocapsa are the common cyanobacterial genera the mats growing in the streams.

 

 

                                                                                                   Cyanobacerial mats

 

                                                                                 Mat.jpg

 

                                                                                       Nostoc and other cyanobacteria growing on moss

                                                                                     moss.jpg

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In Lake Hoare the mats are vertically stratified. Each year one layer is formed and they can be used as indicators of growth and environmental conditions just like tree rings. Similar to microbial mats in other lakes the layers have different pigmentations for light capturing and protection.

 

                                                                                Cyanobacterial mats in Lake Hoare

 

                                                                      LHmat1.jpg

 

After the divers had brought up mat samples from a depth of ca 10 m, we went back to the lab and identified the diversity using light microscopy. The microbial mats contained different cyanobacteria including the genera Oscillatoria, Phormidium, Leptolyngbya and Nostoc.

 

After returning to the Natural History Museum, we will carry out DNA-based methods to characterise their evolutionary relationship to other Antarctica cyanobacteria.