1. Laboratory for Ecological Risk Assessment, National Institute for Public Health and the Environment, Bilthoven, 3720 BA, The Netherlands
2. Department of Environmental Science, Institute for
Water and Wetland Research, Radboud University Nijmegen, Nijmegen, 6500 GL, The Netherlands
3. Department of Conservation Biology, Institute of Environmental Sciences
(CML), Leiden University, Leiden, 2300
RA, The Netherlands