1. Department of Aquatic Sciences and Assessment; Swedish University of Agricultural Sciences; Uppsala Sweden
2. CNR; Istituto per lo Studio degli Ecosistemi; Verbania Pallanza Italy
3. Centre for Limnology; Institute of Agricultural and Environmental Sciences; Estonian University of Life Sciences; Tartu Estonia
4. Institute of Geology; Tallinn University of Technology; Tallinn Estonia
5. Department of Geography; Kansas State University; Manhattan KS USA