1. Department of Systems Ecology, Stockholm University, SE-106 91 Stockholm, Sweden;
2. Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden
3. Center for Limnology, University of Wisconsin, Madison, Wisconsin 53706;
4. Sustainable Ecosystems, CSIRO, Canberra, ACT, 2601, Australia;
5. Aquatic Ecology and Water Quality Management Group, Wageningen Agricultural University, Wageningen, The Netherlands;
6. Department of Environmental Studies, Emory University, Atlanta, Georgia 30322;
7. 16871 Sturgis Circle, Cedar Key, Florida 32625;