Institution: | (1) Limnological Institute, Tjeukemeer Laboratory, De Akkers 47, 8536 VD Oosterzee, The Netherlands;(2) Limnological Institute, Vijverhof Laboratory, Rijksstraatweg 6, 3631 AC Nieuwersluis, The Netherlands;(3) Institute of Inland Water Management and Waste Water Treatment, P.O. Box 17, 8200 AA Lelystad;(4) Department of Nature Conservation, Laboratory of Aquatic Ecology, Agricultural University Wageningen, P.O. Box 8080, 6700 DD Wageningen, The Netherlands |