1. Large River Investigations Research Station Iowa Department of Natural Resources Des Moines Iowa USA
2. Department of Mathematics and Statistics and Department of Biology University of Minnesota Duluth Duluth Minnesota USA
3. Department of Oceanography University of Hawaii at Manoa Honolulu Hawaii USA
4. Department of Aquatic Resources Swedish University of Agricultural Sciences Lysekil Sweden
5. Geological Institute ETH Zürich Zürich Switzerland
6. Laboratory of Ion Beam Physics ETH Zürich Zürich Switzerland