An unusual psychrophilic green alga was isolated from the deepest portion of the photic zone (o0.1% of incident PAR) at a depth of 17m in the permanently ice-covered lake, Lake Bonney, Antarctica. Here we identify and report the first detailed morphological and molecular examination of this Antarctic green alga, which we refer to as strain UWO 241. To determine the taxonomic identity, UWO 241 w...

The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry ...

The distribution and activity of communities of sulfate-reducing bacteria (SRB) and methanogenic archaea in two contrasting Antarctic sediments were investigated. Methanogenesis dominated in freshwater Lake Heywood, while sulfate reduction dominated in marine Shallow Bay. Slurry experiments indicated that 90% of the methanogenesis in Lake Heywood was acetoclastic. This finding was supported by ...

Although anoxygenic photosynthesis is thought to play an important role in the primary productivity of permanently frozen lakes in the Antarctic dry valleys, the bacterial communities responsible for this metabolism remain uncharacterized. Here we report the composition and activity of phototrophic purple bacteria in Lake Fryxell, Antarctica, as determined by analysis of a photosynthesis-specif...

Interest in brines in extreme and cold environments has recently increased after they have been found on Mars. Those brines can be potential new subsurface habitats for peculiar ecosystems. In the McMurdo Dry Valleys of the Antarctic, the best analogue for Mars conditions, only a few cases of brines have been identified in some perennially frozen lakes and in one case in an underground aquifer....

Constraining East Antarctic Ice Sheet (EAIS) evolution during the Holocene is important for exploring forcing mechanisms behind ice sheet retreat and to constrain numerical models that aid predictions of future sea-level rise. Beryllium (Be) isotope analysis bedrock marine sediments have offered unparalleled insight into history since Pliocene, but much EAIS remains poorly studied. Here, we rep...

Ice surface altimetry from ICESat-1 and NASA aircraft altimeter overflights spanning 2002– 09 indicate that a region of lower Crane Glacier, Antarctic Peninsula, shows an unusual temporal pattern of elevation loss: a period of very rapid drawdown ( 91ma between September 2004 and September 2005) bounded by periods of large but more moderate rates (23ma until September 2004; 12ma after September...

Lake Vostok is the largest of the nearly 400 subglacial Antarctic lakes and has been continuously buried by glacial ice for 15 million years. Extreme cold, heat (from possible hydrothermal activity), pressure (from the overriding glacier) and dissolved oxygen (delivered by melting meteoric ice), in addition to limited nutrients and complete darkness, combine to produce one of the most extreme e...