1. Large Lakes Observatory, University of Minnesota, 10 University Drive, Duluth, MN55812, USA
2. Department of Biology, Ghent University, Ledeganckstraat 35, B–9000 Gent, Belgium
3. Department of Fisheries and Oceans, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6
4. Center for Great Lakes Studies, University of Wisconsin, Milwaukee, WI 53201, USA
5. Limnology Laboratory, Department of Biology, University of Regina, Regina, Saskatchewan, Canada S4S 0A2
6. Geological Institute, University of Bergen, Allegt. 41, N–5007 Bergen, Norway
7. Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1