Changes in the abundance, species richness, and size structure of zooplankton under the influence of environmental conditions in the shallow littoral zone of a heated lake

The aim of the study was to analyze the zooplankton abundance and species richness in 2001-2002 in the littoral zone of Lake Gos3awskie and also to determine the impact of environmental conditions (temperature, oxygen content, macrophytes) on the studied zooplankton. The analysis of the biological samples indicated the occurrence of 64 zooplankton species, of which 42 were representatives of Rotifera and 22 of Crustacea. Species richness and biodiversity during the study period were high, while the zooplankton community structure, in additional to the form classified as littoral, also included pelagic species that often dominated the assemblages. The number of zooplankton species decreased as the area occupied by macrophytes increased as well as when water temperature rose. The abundance of zooplankton was low and remained at similar levels in the study years compared. The dominant taxonomic groups in the zooplankton assemblages throughout the study period were Rotifera or Copepoda naupli.