1. Faculty of Biology, Aquatic Ecology Department, University of Duisburg-Essen, Essen, Germany
2. The Steinhardt Museum of Natural History and National Research Center, Tel Aviv University, Tel Aviv, Israel
3. Y. Allon Kinneret Limnological Laboratory, Israel Oceanographic & Limnological Research, Migdal, Israel
4. Umweltbüro Essen, Essen, Germany