| Summary: | Monitoring of physical properties of terrestrial lakes belongs to one of key research activities performed by Czech scientists at James Ross Island. Throughout 2011, water temperature was measured and recorded by dataloggers in 1 h interval in two Antarctic lakes of different size and morphology. The first lake is a large shallow one located in a depression of sedimentary rock (Lachman Lake 1) at the altitude of 10m a.s.l. Lake Dulanek, the second one, is typical small-area water body located on stony glacier surface at the altitude of 220 m a.s.l. Dulanek Lake, thanks to higher altitude, remained frozen for longer period (274 d) of austral winter than Lachman Lake 1 (205 d). Presence of thick snow cover over Dulanek lake during winter period, however, caused higher values of winter minimal temperature (-17.5°C) than those recorded for Lachman lake 1 (several periods below -20.0°C). Mean annual temperature reached -4.6°C and -5.2°C for Lake Dulanek, and Lachman Lake 1, respectively. Shorter summer season accompanied by lower water temperature in Lake Dulanek however, did not bring unfovourable conditions for growth and reproduction of autotrophic organisms. Biomass of autotrophic organisms found in Lake Dulanek was quite high.
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