caa a22 4500 465825508 CHVBK 20180323112148.0 cr unu---uuuuu 170327e19900701xx s 000 0 eng 10.1007/BF02256749 doi (NATIONALLICENCE)springer-10.1007/BF02256749 The Reeuwijk lakes: A five years water quality study in an eutrophic ecosystem [Elektronische Daten] [J. Van Der Vlugt, S. Klapwijk] The Reeuwijk Lakes (The Netherlands) present a typical example of eutrophication in the lower Rhine catchment area. In 1986 restoration of these lakes started by reducing the external P-loading. Two lakes, Lake Elfhoeven and Lake Nieuwenbroek, differing in P-load and residence time were selected for monitoring water quality parameters before (1983-1985) and after (1986-1987) these restoration measures. Reduction of the external P-loading did not result in lower P-concentrations in both lakes. In contrast, P and N increased. This may have been caused by an increase in diffuse discharges. However, seasonal cycles of P and N point to a strong internal loading of nutrients. The concentrations of chlorophyll a and carotene decreased, indicating a lower phytoplankton biomass. However, as C-phycocyanine concentrations increased the relative abundance of cyanobacteria became higher. Seston concentrations and zooplankton densities did not change. Transparency in the lakes slightly decreased after P-reduction and is far too low for the development of any vegetation of submerged waterplants. The typical differences between both lakes remained after restoration measures. The inverse relationship between the concentrations of chlorophyll a and total phosphorus at the two sampled stations remained constant. The differences in phytoplankton composition and the zooplankton biomass give a plausible explanation for this inverse relationship, between the two stations. Restoring the lakes after four decades of P-loading can presumably, not simply be done by lowering the external P-load alone. Supplementary in-lake measures may accelerate the restoration process. Netherlands Hydrobiological Society, 1990 eutrophication nationallicence lake restoration nationallicence water quality nationallicence carbon/chlorophyll ratio nationallicence zooplankton grazing nationallicence Van Der Vlugt J. National Institute of Public Health and Environmental Protection (RIVM), P. O. Box 1, 3720 BA, Bilthoven, The Netherlands aut Klapwijk S. Waterboard of Rijnland, P. O. Box 156, 2300 AD, Leiden, The Netherlands aut Hydrobiological Bulletin Kluwer Academic Publishers 24/1(1990-07-01), 57-67 0165-1404 24:1<57 1990 24 10452 https://doi.org/10.1007/BF02256749 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02256749 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Van Der Vlugt J. National Institute of Public Health and Environmental Protection (RIVM), P. O. Box 1, 3720 BA, Bilthoven, The Netherlands aut NATIONALLICENCE 700 1- Klapwijk S. Waterboard of Rijnland, P. O. Box 156, 2300 AD, Leiden, The Netherlands aut NATIONALLICENCE 773 0- Hydrobiological Bulletin Kluwer Academic Publishers 24/1(1990-07-01), 57-67 0165-1404 24:1<57 1990 24 10452 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer