Dynamics of phytoplankton detritus in a shallow, eutrophic lake (Lake Loosdrecht, The Netherlands)

Otten, Jerko H.; Gons, Herman J.; Rijkeboer, Machteld

doi:10.1007/bf00016096

Cited by 28 publications

(8 citation statements)

References 22 publications

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“…Van Der Vlugt et al (1992) reported that the remaining refractory detritus, resuspended frequently by wind action created high turbidity and thus hindered growth of waterplants needed to balance the system after the biomanipulation. This conclusion is supported by the research outcome of Loosdrecht lakes (Gons & Otten, 1991;Gons et al, 1992;Otten et al, 1992). It still needs to be demonstrated whether fixation with iron(III)chloride will stabilize the extremely loose sediment particles .…”

Section: Resume Recovery Of Shallow Inland Watersmentioning

confidence: 90%

“…According to model calculations these measures will reduce chlorophyll a concentration (lanse et al, 1992). This will mark the beginning of recovery, since production of phytoplankton, thus also of the newlyformed detritus, will be reduced (GOllS et al, 1992;Otten et al, 1992). After reduction of external phosphorus and response of the ecosystem, the supplementary measures are more feasible (lanse et al, 1992).…”

Section: Resume Recovery Of Shallow Inland Watersmentioning

confidence: 99%

See 1 more Smart Citation

Restoration and recovery of shallow eutrophic lake ecosystems in The Netherlands: epilogue

Liere

Gulati²

1992

Restoration and Recovery of Shallow Eutrophic Lake Ecosystems in the Netherlands

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During the symposium 'Restoration and recovery of shallow lake ecosystems in The Netherlands' studies on restoration of eutrophic lakes were addressed and discussed. Many Dutch shallow lakes have received high external loadings of phosphorus through supply water that is influenced by the River Rhine and loadings in The Netherlands. Two important Action Plans (the Rhine Action Plan, the North Sea Action Plan) are now in operation to reduce nutrient emissions. The targets set are not likely to be fully reached, so that supplementary reduction of phosphorus supplied to inland fresh waters will be required. In several shallow lakes such a reduction has been achieved recently, but without leading to discernible recovery. The main causes of delay are phosphorus storage and its subsequent release from sediments and foodweb; however, the remaining extraneous phosphorus supply is often still too high. Supplementary actions are, therefore, called for. A further reduction of phosphorus inputs is suggested, besides supplementary measures proposed, viz. dredging, flushing, biomanipulation, chemomanipulation. Restoration to the past situation via upwelling groundwater appeares to be feasible in some cases. There is a common consensus that each lake behaves differently depending to its morphology, hydrology and history of eutrophication. Therefore each lake has to be studied before restoration measures can be applied. Besides, the ecosystem should not only be studied as a separate entity, but as a part of systems of a higher integration level.

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Section: Resume Recovery Of Shallow Inland Watersmentioning

confidence: 90%

Section: Resume Recovery Of Shallow Inland Watersmentioning

confidence: 99%

Restoration and recovery of shallow eutrophic lake ecosystems in The Netherlands: epilogue

Liere

Gulati²

1992

Restoration and Recovery of Shallow Eutrophic Lake Ecosystems in the Netherlands

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“…The winter values of chlorophyll-a are often underpredicted, possibly because the phytoplankton can survive some days in the upper sediment layer (Otten et al, 1992) and, if resuspended within that period, will be measured in the water again. The measured summer chlorophyll-a concentration in Lake Loosdrecht in 1982, when the loading was still high, is lower than simulated by the model and also lower than the concentration in 1983.…”

Section: Discussionmentioning

confidence: 99%

“…In both phases, a distinction is made between soluble reactive phosphorus (SRP), which is assumed to be biologically available, and adsorbed inorganic phosphorus. The organic matter in the lake, which is rich in iron, has a high adsorption capacity for phosphorus (Otten et al, 1992).…”

Section: General Featuresmentioning

confidence: 99%

A mathematical model of the phosphorus cycle in Lake Loosdrecht and simulation of additional measures

1992

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The phosphorus cycle in the ecosystem of the shallow, hypertrophic Loosdrecht lakes (The Netherlands) was simulated by means of the dynamic eutrophication model PCLOOS. The model comprises three algal groups, zooplankton, fish, detritus, zoobenthos, sediment detritus and some inorganic phosphorus fractions. All organic compartments are modelled in two elements, carbon and phosphorus. Within the model system, the phosphorus cycle is considered as completely closed. Carbon and phosphorus are described independently, so that the dynamics of the P/C ratios can be modelled. The model has been partly calibrated by a method based on Bayesian statistics combined with a Range Check procedure.Simulations were carried out for Lake Loosdrecht for the periods before and after the restoration measures in 1984, which reduced the external phosphorus loading to the lake from ca. 2 mgP m-* d-' to lmgPm-*d-l.The model outcome was largely comparable with the measured data. Total phosphorus has slowly decreased from an average 130 PgP l-' to ca. 80 PgP l-', but chlorophyll-a (ca. 15opg1-', summer-averaged) and seston concentrations (8-15 mgC l-') hardly changed since the restoration measures. About two-thirds of the seston consisted of detritus, while the phytoplankton remained dominated by filamentous cyanobacteria. The P/C ratio of the seston decreased from ca. 1.0% to 0.7 %, while the P/C ratios of zooplankton, zoobenthos and fish have remained constant and are much higher. The system showed a delayed response to the decreased phosphorus loading until a new equilibrium was reached in ca. five years. Major reasons for the observed resilience of the lake in responding to the load reduction are the high phosphorus assimilation efficiency of the cyanobacteria and the high internal recycling of phosphorus. A further reduction of nutrient loading, perhaps in combination with additional measures like biomanipulation, will be the most fruitful additional restoration measure.

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“…Because the lakes are shallow, wind-induced resuspension of epipelon and peat fragments frequently occurs (Gons et al, 1986;Gons & Otten, 199 1;Otten et al, 1992). The light climate is negatively affected by the resuspended matter, which favours the filamentous cyanobacteria (Gons & Otten, 1991).…”

Section: Introductionmentioning

confidence: 99%

Multivariate analysis of the plankton communities in the Loosdrecht lakes: relationship with the chemical and physical environment

Tongeren¹,

Liere²,

Gulati³

et al. 1992

Hydrobiologia

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Data on the water temperature, Secchi depth, water chemistry and phytoplankton and zooplankton of the Loosdrecht lakes, collected during an eight-years monitoring study (1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990), were examined using Principal Components Analysis (PCA) and Redundancy Analysis (RDA). The Loosdrecht lakes are highly eutrophic lakes, in which several restoration measures were taken from 1970 to 1986. These measures included the diversion of sewage by the construction of sewerage and additional reduction of external phosphorus-loading by supplying from 1984 onwards water from the Amsterdam Rhine Canal, which had phosphorus removed from it, and which replaced the inlet of highly eutrophic water from the River Vecht. The descriptive statistical models based on this study show that, although the total P in the lake was decreasing, probably because of the reduced external loading, the sum of the densities of cyanobacteria and Prochlorothrix hollandica was increasing. The dominant species of the zooplankton community (rotifers and crustaceans) did not show changes related to the restoration measures. It is concluded that the available data are insufficient to predict future changes, but that the changes in the past can be described well by a simple linear ordination model.

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Dynamics of phytoplankton detritus in a shallow, eutrophic lake (Lake Loosdrecht, The Netherlands)

Cited by 28 publications

References 22 publications

Restoration and recovery of shallow eutrophic lake ecosystems in The Netherlands: epilogue

Restoration and recovery of shallow eutrophic lake ecosystems in The Netherlands: epilogue

A mathematical model of the phosphorus cycle in Lake Loosdrecht and simulation of additional measures

Multivariate analysis of the plankton communities in the Loosdrecht lakes: relationship with the chemical and physical environment

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