Polarforschung 66 (1/2),33- 52,1996 (erschienen 1999) The Chemical Stratification and Microbial Communities of Ace Lake, Antarctica: A Review of the Characteristics of a Marine-Derived

• Main Author: Meromictic Lake
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Ace Lake; Saline Lake; Vestfold; Antarc*; Antarctica; Ice cap; Polar Ice Cap
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.456.7961; http://epic.awi.de/28380/1/Polarforsch1996_1-2_4.pdf

Abstract: This article reviews the history, chcmical stratification. biology and biogeochemisuy of Ace Lake, which is one of the many marine-derrved meromictic (permanently stratified) lakes in the Vestfold Hil ls, Eastern Antarctica. The lake has an area of 18 ha, a maximum depth of 25 m, and a salinity range from 7 to 43 g I". The lake mixes to a depth of 7 m in late winter as a result of brine freeze out during ice Ionnation. Deeper mixing is precluded by a sharp halocline. The water beneath 12 m is permanently anoxic, The lake was formed approximately 10,800 yr BP as the polar ice cap mclted. Sea level rise 7,800 yr BP rcsultcd in invasion of seawater into thc initially freshwater lake. Subsequently, sea level dropped, and rhe now saline lake became isolated from the ocean. The biota of the lake was derived from spccies trapped whcn the connection betwecn the lake and the occan was cut off. The oxic zone above 12 m supports a relatively simple community which includes microbial mats, four major species of phytoplankton (including a picocyanobacterium), two copcpod species, and a variety of heterotrophic flagellatcs and ciliatcs. The anoxic zone