Tahtalı Dam Lake is one of the most important drinking water reservoir of Izmir. To determine of zooplankton composition of the reservoir, field studies were arranged monthly, between May 2006 and April 2007. Samples were taken from 3 stations by using plankton net with a mesh size of 55µm. both horizontally and vertically. The collected materials were immediately fixed in 4% formalin. At the end of the study, totally 65 taxa were determined; of them 37 belong to Rotifera, 20 belong to Cladocera and 8 belong to Copepoda.
