Gerard N. J. ter Heerdt

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The effects of fish stock reduction (biomanipulation) was studied in an 85 ha shallow peaty turbid lake. The lake cleared in a 4-week period in April–May 2004, which demonstrated that biomanipulation can be effective in peaty lakes. We demonstrated that it is possible to reduce the fish stock to <25 kg ha−1 benthivorous fish and <15 kg ha−1 planktivorous(More)
Biomanipulation of eutropicated peaty lakes has rarely been successful; clear water with dense macrophyte stands fails to develop in most cases. It was unclear whether (1) high turbidity due to resuspension by benthivorous fish or wind is the major cause of low macrophyte density or whether (2) the establishment of submerged macrophyte stands is prevented(More)
For 7 years, development of submerged vegetation was monitored after fish stock removal during the final phase of a restoration program in the shallow, 2.1 km2 Lake Loenderveen (The Netherlands). The lake shifted from a turbid, phytoplankton-dominated state, to a clear, macrophyte-dominated state. Vegetation development was very dynamic during years 1–5.(More)
In order to set ecological goals and determine measures for the European Water Framework Directive, the effects of climate change on lake ecosystems should be estimated. It is thought that the complexity of lake ecosystems makes this effect inherently unpredictable. However, models that deal with this complexity are available and well calibrated and tested.(More)
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