Map of the Kopački Rit floodplain (floodplain location in the north-east of Croatia is marked with a black dot) during (A) low-water period (Danube water level between 1 and 1.5 m) and (B) high-water period (Danube water level around 5 m) (maps of the floodplain area are modified from Schwarz (2005) and Mihaljević and Stević (2011)). Dotted line represents the border of the floodplain area. Study area (Lake Sakadaš) is located in the western part of the floodplain. The sampling station in the lake is marked with a grey dot.