Eddy Lammens

Rijkswaterstaat · Waterquality

The hypothesis that the variability in prey-size selection of filter-feeding bream (Abramis brama) is related to sieve adjustment was tested by feeding bream of approximately 20 and 30 cm standard length with daphnids. The size-selective feeding observed in experiments was compared with predicted selectivity curves derived from the channel width of...

Industrial sieves retained all cycloid copepods with a width larger than their mesh size, but Daphnia, with a width up to 1.4 times the mesh size, still passed through them. Daphnia have a lower depth/width ratio than copepods (0.599 and 0.882, respectively). Therefore, Daphnia could pass through the square meshes diagonally. In filter-feeding expe...

The growth rate of young-of-the-year of the six most abundant fish species (smelt (Osmerus eperlanus), pikeperch (Stizostedion lucioperca), perch (Perca fluviatilis), ruffe (Gymnocephalus cernua), bream (Abramis brama), and roach (Rutilus rutilus)) in Lake Tjeukemeer was predicted from water temperature using the model . For each species the model...

The resource partitioning of the bream (Abramis brama) and eel (Anguilla anguilla) populations in Lake Tjeukemeer, The Netherlands, was related to the variation in abundance of their most important food organisms, Daphnia hyalina and larval chironomids. Niche shifts of both bream and eel populations were related to the abundance of young planktivor...

Projet OLIGO financé par Veolia Eaux et des entreprises berlinoises

IJsselmeer was formed in 1932 through the closure of the Afsluitdijk that separated the artificial lake from the former Zuiderzee estuary. The palaeoecology of IJsselmeer was studied on a 63-cm-long sediment core. Lithology and microfossil data, particularly the diatom flora, clearly show the transition from the marine Zuiderzee into the freshwater...

An individual-based model describing the growth of zebra mussels (Dreissena polymorpha) is presented. The model is spatially explicit and predicts length¿frequency distributions of zebra mussels. The parameters and model inputs with the strongest effect on the model outcomes were identified using a Monte Carlo sensitivity analysis. Using a cluster...

The European Water Framework Directive (WFD) obliges EU member states to define ecological goals for water bodies and, if necessary, to take measures to achieve these goals by 2015. The goals and measures for the water bodies in the IJsselmeer area of The Netherlands are elaborated in this study, following an approach described by Irmer & Pollard (...

For a century eutrophication has been the most serious environmental threat to lakes in the densely populated or agricultural areas of Europe. During the last decades, however, major efforts have been used to reduce the external nutrient loading, not least from point sources. Despite these comprehensive efforts, lake eutrophication remains a major...

Summary 1. Eutrophication constitutes a serious threat to many European lakes and many approaches have been used during the past 20-30 years to improve lake water quality. Results from the various lake restoration initiatives are diverse and the long-term effects are not well described. 2. In this study we evaluated data from more than 70 restorati...

In this paper we analyze a long-term dataset on the recovery from eutrophication of Lake Veluwe (The Netherlands). Clear hysteresis was observed in a number of ecosystem variables: the route to recovery differed significantly from the route that led to loss of clear water. The macrophyte dominated state disappeared in the late 1960s at TP above 0.2...

Since the late 1980s, shallow lakes in Europe and North America have been receiving concerted attention from limnologists, fishery biologists and lake managers. These developments relate to deterioration of water quality in the lakes due to pollution and accelerated eutrophication, caused by increased urbanization and agriculture in the lake catchm...

In deze studie evalueren we gegevens van 28 Nederlandse en 50 Deense meren waar effectgericht maatregelen zijn toegepast, waaronder voornamelijk actief biologisch beheer door afvissen van brasem en blankvoorn. Daarnaast zijn in sommige meren ook andere maatregelen toegepast, zoals baggeren en chemische fosfaatfixatie in het sediment. In meer dan de...

Om de visstand in de Nederlandse grote rivieren te kunnen beoordelen, worden ieder jaar routinematige bemonsteringen uitgevoerd. Deze gegevens worden verzameld ten behoeve van beleidsvorming en evaluatie van het Ministerie van Landbouw, Natuurbeheer en Voedselveiligheid (LNV, Directie Visserij) en het Ministerie van Verkeer en Waterstaat. Deze moni...

1. The effect of benthivorous bream and carp on sediment resuspension and the concentrations of nutrients and chlorophyll a were studied in sixteen experimental ponds (mean depth 1m, mean area 0.1 ha, sandy clay/clay sediment), stocked with bream or carp at densities varying from 0 to 500 kg ha−1. Planktivorous perch (Perca fluviatilis L.) were add...

Shallow lakes and reservoirs are very common in Europe. They harbour a wide variety of organisms and are an important component of the landscape structure. In addition to their ecological role, they also support a wide array of socio-economic activities, such as fisheries, recreation, water storage (flood prevention) and water supply for agricultur...

Climate change will alter freshwater ecosystems but specific effects will vary among regions and the type of water body. Here, we give an integrative review of the observed and predicted impacts of climate change on shallow lakes in the Netherlands and put these impacts in an international perspective. Most of these lakes are man-made and have pres...

1. This synthesis examines 35 long-term (5–35 years, mean: 16 years) lake re-oligotrophication studies. It covers lakes ranging from shallow (mean depth <5 m and/or polymictic) to deep (mean depth up to 177 m), oligotrophic to hypertrophic (summer mean total phosphorus concentration from 7.5 to 3500 ug L-1 before loading reduction), subtropical to...

The fish community in the shallow Lake Veluwe (3400 ha) has recently changed in composition. The total biomass of fish decreased to ca. 35% of the original biomass. The change in fish biomass followed the introduction of a commercial fishery and was in its turn followed by a rapid expansion of macrophyte beds dominated by Chara aspera Deth. ex Will...

Various approaches to modeling the population dynamics and demography of Daphnia have been published. These methods range from the simple egg-ratio method, to mathematically complex models based on partial differential equations and numerically complex individual-based Daphnia population models. The usefulness of these models in unraveling the popu...

SUMMARY 1. The development of bream populations, water transparency, chlorophyll-a concentration, extent of submerged vegetation and densities of the zebra mussel, Dreissena polymorpha, were analysed in three shallow eutrophic lake systems subject to different fish management. 2. In Lake Veluwemeer, the bream population was reduced from c. 100 to 2...

Unraveling the mechanisms that drive dynamics of multi-species fish communities is notoriously difficult. Not only are the interactions between fish populations complex, but also the functional niche of individual animals changes profoundly as they grow, making variation in size within populations and even within cohorts highly important to conside...

The central role of fish in lake restoration and management has a practical purpose: fish are much easier to manipulate than nutrients, phytoplankton and zooplankton, and therefore they are a relatively easy (additional) instrument in restoration and management. The management of the fish stock may be a measure of water quality, of fish stock compo...

Formation of year-class strength of bream Abramis brama, the most abundant fish in shallow eutrophic Lake Tjeukemeer, was studied during a 14-year period. Although the size of the spawning stock of bream was rather stable during this period, analysis of length—frequency distributions indicates that it comprised only a few year-classes. The strength...

Formation of year-class strength of bream Abramis brama, the most abundant fish in shallow eutrophic Lake Tjeukemeer, was studied during a 14-year period. Although the size of the spawning stock of bream was rather stable during this period, analysis of length-frequency distributions indicates that it comprised only a few year-classes. The strength...

Biomanipulation measures in the Netherlands are usually a combination of a drastic fish stock reduction and an introduction of pike fingerlings. In three small shallow lakes (Noorddiep, Bleiswijkse Zoom and Zwemlust) these measures resulted in a clear water state and the development of macrophytes. After the measures the fish community developed di...

A model of an animal cohort foraging on logistically growing food is analyzed. The problem is captured in three differential equations, one for food density and two for the state of the animal cohort, keeping track of body weight and number of individuals, respectively. When the animals efficiently exploit their food to low densities, the model pro...

The growth rate of young-of-the-year of the six most abundant fish species (smelt (Osmerus eperlanus), pikeperch (Stizostedion lucioperca), perch (Perca fluviatilis), ruffe (Gymnocephalus cernua), bream (Abramis brama), and roach (Rutilus rutilus)) in Lake Tjeukemeer was predicted from water temperature using the model . For each species the model...

The effects of fish stock reduction have been studied in 3 Dutch lakes (Lake Zwemlust, Lake Bleiswijkse Zoom and Lake Noorddiep) and 1 Danish lake (Lake Væng) during 4–5 years. A general response is described. The fish stock reduction led in general to a low fish stock, low chlorophyll-a, high Secchi-disc transparency and high abundance of macrophy...

In 1990 an experiment started in the large and shallow lake Wolderwijd (2700 ha, mean depth 1.5 m) to improve the water quality. About 75% of the fish stock was removed (425 000 kg fish). The fish was mainly composed of bream and roach. In May 600 000 young pikes (3–4 cm) were introduced. In May 1991 the water became very clear (Secchi depth 1.8 m)...

In October–December 1990, the large barbs (Barbus) that contribute more than 35% of the catch in lake Tana (northern Ethiopia) were studied. Previous authors (Rüppell 1837, Boulenger 1902,1911, Bini 1940) described from 6 to 23 (sub)species for the lake. Banister (1973) lumped all of these into one subspecies: Barbus intermedius intermedius Rüppell...

Most of the lakes in The Netherlands are turbid and without vegetation. This is regarded as the result of increasing eutrophication within the last decades. Under these conditions common bream, roach, and white bream are the most common cyprinids. In six shallow (1–3 m), wind exposed lakes the abundance of common bream and roach was linked to the a...

The fish community in the Loosdrecht lakes is dominated by bream, pikeperch and smelt and is characteristic of shallow eutrophic lakes in The Netherlands. The biomasses of the respective fish species amount to ca. 250, 25 and 10 kg ha–1 and correspond to those in Tjeukemeer, another lake in The Netherlands. The average size of bream, however, is mu...

A model has been developed to describe the process of switching between particulate- and filter-feeding in common bream, Abramis brama, in relation to fish size and zooplankton density. The model assumes that the encounter rate of fish and zooplankton is determined by the density of zooplankton and the swimming speed of fish. However, if zooplankto...

The effect of benthivorous bream and carp on resuspension was studied in 16 ponds (mean depth lm, 0.1 ha, clay sediment). The ponds were stocked with biomasses varying from 50–500 kg/ha with and without perch (Perca fluviatilis). Two reference ponds were used, one with only perch and one without fish. Sediment traps were used to determine the amoun...

A new model for filter feeding in bream (Abramis brama, Cyprinidae) is presented based on the three dimensional architecture of the branchial sieve. Transverse ridges on the upper surface of the gill arches form a system of channels in which food particles appear to be retained. These ridges are formed by a fleshy interconnection between the middle...

Cyprinids comprise a wide variety of specialists and generalists feeding on all trophic levels. Detailed knowledge is available about the common European cyprinids from running and stagnant fresh water. Most feed on the secondary producers: Zooplankton, macrocrustaceans, larvae, pupae and adults of insects, oligochaetes, bryozoans, snails, and muss...

The interactions between the higher trophic levels in a shallow eutrophic lake were studied during the course of a year. Three fish species determined the main pathways of organic matter flow within the system: the predominantly planktivorous bream (Abramis brama), the obligate planktivorous smelt (Osmerus eperlanus), and the piscivorous pikeperch...

At the First Biomanipulation Conference held in Amsterdam (8–11 August 1989), studies presented considered mainly trophic interactions in lakes, enclosures and laboratory systems. Studies on the interactions between phytoplankton and zooplankton emphasized the edibility of the phytoplankton in relation to the zooplankton size structure and the trop...

Bream Abramis brama, pikeperch Stizostedion lucioperca and smelt Osmerus eperlanus were the most dominant fishes; roach Rutilus rutilus, white bream Blicca bjoerkna, perch Perca fluviatilis and ruffe Gymnocephalus cernuus comprised <10% of the total catches. After the termination in 1977 of the intensive gillnet fishery both pikeperch >50 cm and br...

To study the impact of cyprinids on algae, zooplankton and physical and chemical water quality, ten drainable ponds of 0.1 ha (depth 1.3 m) were each divided into two equal parts. One half of each pond was stocked with 0 + cyprinids (bream, carp and roach of 10–15 mm), the other was free of fish. The average biomass of the 0 + fish at draining of t...

During the summer months of 1974–1985 chlorophyll-a and total P concentration, biomass of Daphnia hyalina, smelt Osmerus eperlanus, bream Abramis brema and pikeperch Stizostedion lucioperca, water temperature and water intake from lake IJsselmeer were monitored in Tjeukemeer. During this period there were manipulations with the bream and pikeperch...

External phosphorus loads to three shallow lakes in the Netherlands were reduced by eliminating waste-water discharge and by dephosphorization of the supply water, with which water level is controlled. Concentrations of total-phosphorus and chlorophyll a were significantly reduced during 1980–1986 in L. Breukeleveen, but not in L. Vuntus and L. Loo...

Two experiments (I and II) were performed in drainable ponds. Yellow eels Anguilla anguilla (L.) were stocked in early June at three biomasses: 10, 20 and 60 kg · ha−1 in experiment I; and 10, 20 and 40 kg · ha−1 in experiment II. The mean body weights were 27.0 and 24.2 g respectively. Glass eels were stocked only in experiment II at equal densiti...

The technique of X-ray cinematography was used to study pharyngeal movements in Abramis brama (L.). The theoretical and practical problems in X-ray cinematography of feeding fish are discussed, as well as criteria for the selection of images suited for detailed measurements. Respiration and filter-feeding on Daphnia pulex (length c. 1 mm) show diff...

Mouth widths of eels in three Dutch lakes were compared relative to feeding conditions over two years. Average mouth width varied by season and year and per lake. Of two groups of feeding specialists distinguished in each population chironomid feeders showed a smaller mouth width compared to fish feeders of the same body length. Proportions of thes...

In the last decennia eutrophication has caused a shift in the species composition of fish communities in Dutch fresh waters. The changes have led to the disappearance of vegetation in lakes and ponds; zooplankton and chironomids are now the most abundant food organisms for fish. In the turbid, open waters bream and pikeperch are the dominant fish s...

This thesis describes the structure of fish communities in Tjeukemeer (21 km <sup> 2 </SUP>) and some other surrounding very eutrophic lakes and emphasizes the interactions of the fishes with each other and their food organisms (predation and (exploitative) competition). It is a compilation of seven articles which appeared in international journals...

The planktivorous feeding of bream, Abramis brama on Daphnia hyalina and Bosmina coregoni was analyzed in a stepwise regression analysis with the average size (and standard deviation) of consumed organisms as dependent variable and the size of the fish, the average size (and standard deviation) of the organisms and their density in the environment...

The bream (Abramis brama L.) population of Tjeukemeer was studied for three successive years. The growth, condition, gonad development, diet and feeding conditions of the fish are described. Food competition for two years with the then abundant young planktivorous smelt (Osmerus eperlanus) and perch (Perca fluviatilis) resulted in a decreased growt...

The macrophyte production and the transport of particulate organic matter between marsh and adjacent estuary have been investigated for a 0.3 km2 salt marsh along the Oosterschelde estuary, The Netherlands.The primary production of macrophytes, measured with Smalley's (1959) method was 837 to 1030 g dry organic matter·m−2·y−1. Measurements of amoun...

In spring, summer and autumn, there is a continuous decomposition of Nymphoides leaves by means of physiological and consumptive or damaging processes.The first process can take place in two ways: viz. by gradually dying off of the oldest leaves and by mass decomposition after the flowering period. In autumn, when the growth stops, this process of...