Using automated overwinter sampling devices, we collected preserved phytoplankton samples from multiple depths in Lake Fryxell, a permanently ice-covered lake in southern Victoria Land, Antarctica. Photosynthetic algae were maintained in a stable water column throughout winter darkness. The algal taxa overwintered in different ways in a species-specific manner. Typical vegetative cells were the most abundant form for all species found in the water column. Populations of one chlorophyte, Stichococcus sp., were observed in winter, but the species was absent in both summers.
Lake Bonney (McMurdo Dry Valleys, east Antarctica) represents a year-round refugia for life adapted to extreme conditions. Lake level has risen by more than 3 m since 2004, but impacts of rapid lake level rise on phytoplankton community structure is also poorly understood.