The study area (Figure 1) is an old disconnected oxbow lake of the river Elbe situated in
Central Bohemia (Czech Republic, GPS 50◦1048.005N, 14◦4732.713E). This lake was formerly
part of the river Elbe but has been isolated since around 1930, when the river was
channelised. The lake has one small inflow and no outflow. From November to March ice and
snow may occur. The extent of the ice cover is directly dependent on weather conditions.
During ice cover periods, ice holes approximately 5 × 10 m in size are cut by members of
the local anglers’ organisation. Holes are cut irregularly about twice a month. The lake represents
a highly valuable natural habitat that is part of the “Hrbácˇ kovy tu° neˇ ” natural reserve and
also part of the European Ecological Network Natura 2000. The maximum depth of the lake
reaches 2.3 m. The field work was authorised by the Regional Office of the Central Bohemia
Region, Department of Environment and Agriculture (permit No. 114123/2010/KUSK-3).