Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Sediment Disposals in Estuarine Channels Alter the Eco-Morphology of Intertidal Flats
    Vet, P.L.M. de; Prooijen, B.C. van; Colosimo, I. ; Ysebaert, T. ; Herman, P.M.J. ; Wang, Z.B. - \ 2020
    Journal of Geophysical Research: Earth Surface 125 (2020)2. - ISSN 2169-9003
    ecology - estuaries - intertidal flats - morphology - sediment disposals - sediment management

    Dredging of navigation channels in estuaries affects estuarine morphology and ecosystems. In the Western Scheldt, a two-channel estuary in the Netherlands, the navigation channel is deepened and the sediment is relocated to other parts of the estuary. We analyzed the response of an intertidal flat to sediment disposals in its adjacent channel. Decades of high-frequency monitoring data from the intertidal flat show a shift from erosion toward accretion and reveal a sequence of cascading eco-morphological consequences. We document significant morphological changes not only at the disposal sites, but also at the nearby intertidal flats. Disposals influence channel bank migration, driving changes in the evolution of the intertidal flat hydrodynamics, morphology, and grain sizes. The analyzed disposals related to an expansion of the channel bank, an increase in bed level of the intertidal flat, a decrease in flow velocities on this higher elevated flat, and locally a decrease in grain sizes. These changes in turn affect intertidal flat benthic communities (increased in quantity in this case) and the evolution of the adjacent salt marsh (retreated less or even expanded in this case). The shifts in evolution may occur years after dredged disposal begins, especially in zones of the flats farther away from the disposal locations. The consequences of sediment disposals that we identify stress the urgency of managing such interventions with integrated strategies on a system scale.

    Governance conditions for successful ecological restoration of estuaries: lessons from the Dutch Haringvliet case (first online)
    Buitenhuis, Yannick ; Dieperink, C. - \ 2019
    Journal of Environmental Planning and Management 62 (2019)11. - ISSN 0964-0568 - p. 1990 - 2009.
    delta area - ecological restoration - estuaries - governance - Haringvliet
    Ecological restoration projects may provide solutions for degraded ecosystems in estuaries, but are challenging due to complex governance processes. Scientific studies on the latter are limited. The aim of this paper is to provide a better understanding of the governance process aiming at ecological restoration in estuaries. Based on a literature review, five success conditions for ecological restoration projects in estuaries were formulated. These conditions concern: (1) the presence of options for experimentation; (2) the use of the right communication strategies; (3) a pro-active role of key individuals; (4) sufficient project support; (5) active stakeholder and knowledge integration. These conditions were elaborated upon in a case study on the reopening of the sluices in the Dutch Haringvliet and by conducting seven expert interviews. The case study was a clear “example of failure” due to absence of several conditions. We conclude with some
    recommendations to enhance future ecological restoration projects.
    Natura 2000 in het habitatrichtlijngebied Eems-Dollard
    Baptist, M.J. ; Geelhoed, S.C.V. - \ 2016
    IMARES (Rapport / IMARES C054/16) - 43
    natura 2000 - eems-dollard - habitatrichtlijn - waddenzee - estuaria - habitats - vogels - fauna - natura 2000 - eems-dollard - habitats directive - wadden sea - estuaries - habitats - birds - fauna
    Het doel van dit rapport is uit te werken welke verbeteringen van de Natura 2000-waarden behaald moeten worden in de Eems-Dollard na aanwijzing. Van belang hierbij is met welke referentietoestand moet worden vergeleken. De afspraak is dat de referentietoestand wordt bepaald door het jaar waarin een gebied op de Europese lijst van Gebieden van Communautair Belang wordt bijgeschreven.
    Tidal river dynamics : Implications for deltas
    Hoitink, A.J.F. ; Jay, D.A. - \ 2016
    Reviews of Geophysics 54 (2016)1. - ISSN 8755-1209 - p. 240 - 272.
    delta evolution - estuaries - river discharge - tidal analysis - tidal river - wetlands

    Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion, a realm that can extend inland hundreds of kilometers. One key phenomenon resulting from this interaction is the emergence of large fortnightly tides, which are forced long waves with amplitudes that may increase beyond the point where astronomical tides have become extinct. These can be larger than the linear tide itself at more landward locations, and they greatly influence tidal river water levels and wetland inundation. Exploration of the spectral redistribution and attenuation of tidal energy in rivers has led to new appreciation of a wide range of consequences for fluvial and coastal sedimentology, delta evolution, wetland conservation, and salinity intrusion under the influence of sea level rise and delta subsidence. Modern research aims at unifying traditional harmonic tidal analysis, nonparametric regression techniques, and the existing understanding of tidal hydrodynamics to better predict and model tidal river dynamics both in single-thread channels and in branching channel networks. In this context, this review summarizes results from field observations and modeling studies set in tidal river environments as diverse as the Amazon in Brazil, the Columbia, Fraser and Saint Lawrence in North America, the Yangtze and Pearl in China, and the Berau and Mahakam in Indonesia. A description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges.

    Ecotopenkaart voor het Eems-Dollard estuarium
    Ysebaert, T. ; Wal, J.T. van der; Tangelder, M. ; Groot, A.V. de; Baptist, M.J. - \ 2016
    Yerseke : IMARES (Rapport / IMARES C059/15) - 48
    estuaria - aquatische ecosystemen - habitatbeheer - ecologische beoordeling - aquatische ecologie - eems-dollard - estuaries - aquatic ecosystems - habitat management - ecological assessment - aquatic ecology - eems-dollard
    Dit rapport geeft een eerste aanzet tot het maken van een actuele ecotopenkaart voor het Eems-Dollard estuarium (NL en D deel, excl. Unterems) volgens de ZES.1 methodiek. Dit is één van de instrumenten die kan worden gebruikt voor het evalueren van mogelijke maatregelen in het MIRT-onderzoek en de mogelijke MIRT-verkenning Eems-Dollard. Daarnaast kan deze dienen als aanzet voor een operationele ecotopenkaart van het Eems-Dollard estuarium voor meer algemene beleidsondersteuning. De methode laat tevens toe een vergelijking te maken met ecotopenkaarten van bijv. de Westerschelde.
    Blueprint for an Ems-Dollard ecoystem model study
    Brinkman, A.G. - \ 2015
    Den Helder : IMARES (Report / IMARES C158/15) - 39
    aquatic ecosystems - estuaries - aquatic ecology - models - eems-dollard - aquatische ecosystemen - estuaria - aquatische ecologie - modellen - eems-dollard
    Since in the ecological model study as performed in that research phytoplankton and phytobenthos were included, but no higher trophic levels, it was suggested to perform another ecosystem model study that does include higher trophic levels. In this report, such a model set‐up is presented. First, a short overview of existing (model‐)knowledge will be presented, including their strengths and shortcomings. Next, the present EcoWasp‐model is introduced, and possible improvements or needed extensions are mentioned. Also, the developed WasMo‐model (Gerla et al, 2014) will be mentioned.
    Review van ecologische probleembeschrijvingen voor het Eems estuarium
    Baptist, M.J. ; Tamis, J.E. - \ 2015
    Den Burg : IMARES (Rapport / IMARES Wageningen UR C076/15) - 31
    ecologisch herstel - herstelbeheer - estuaria - ecologische verstoring - waterkwaliteit - aquatische ecologie - eems-dollard - ecological restoration - restoration management - estuaries - ecological disturbance - water quality - aquatic ecology - eems-dollard
    Het Eems estuarium heeft al geruime tijd te kampen met ecologische problemen van diverse aard. In het Bestuurlijk Overleg MIRT (Meerjarenprogramma Infrastructuur, Ruimte en Transport) NoordNederland in het najaar van 2013, is afgesproken dat rijk en regio een MIRT-onderzoek Eems-Dollard starten. Het rijk en de provincie Groningen zijn gezamenlijk de opdrachtgevers voor dit onderzoek. Het doel van het MIRT-onderzoek is het voorbereiden van keuzes rondom de Nederlandse strategie in de bilaterale samenwerking met Duitsland, gericht op het ecologisch behoud en herstel van het EemsDollard estuarium in balans met kustveiligheid, ruimtelijke kwaliteit en economische ontwikkeling. Dit rapport maakt deel uit van MIRT-onderzoek Eems-Dollard Fase II spoor 1, het ecologische kennisspoor. Het bouwt voort op resultaten uit MIRT-onderzoek Fase I en andere bestaande probleembeschrijvingen. Dit rapport is het resultaat van een reviewstudie van ecologische probleembeschrijvingen voor het Eemsestuarium.
    Onderzoekprogramma ecologisch herstel Eems-Dollard
    Brinkman, A.G. ; Baptist, M.J. - \ 2015
    Den Burg : IMARES (Rapport / IMARES Wageningen UR C008/15) - 40
    estuaria - aquatische ecosystemen - ecologisch herstel - wetlands - eems-dollard - onderzoeksprojecten - estuaries - aquatic ecosystems - ecological restoration - wetlands - eems-dollard - research projects
    Al vele jaren spelen er discussies over de ecologische kwaliteit van het Nederlandse Waddengebied. Vijftig jaar geleden speelde de mogelijke inpoldering. Contaminanten als dieldrin en PCB’s waren een belangrijk thema in de jaren erna en vanaf de jaren ’90 tot (deels) nu toe is schelpdiervisserij onderwerp van studie waarbij ook gesteld wordt dat er een verzanding van het systeem optreedt. Streefdoelen voor de waterkwaliteit zijn in de Kaderrichtlijn Water vastgelegd, het gehele Waddengebied (inclusief dus de Eems-Dollard) is aangewezen als Vogel- en Habitatrichtlijngebied, en is daarmee Natura2000-gebied. Hiermee zijn vele kwaliteitsdoelen geformuleerd, waarmee de beheerder verplicht wordt maatregelen te treffen opdat daar aan voldaan wordt.
    Maatregelen ter verbetering van het Eems - Dollard estuarium: Quick scan van 92 MIRT maatregelen en relatie met DPSIR
    Slijkerman, D.M.E. ; Tamis, J.E. ; Baptist, M.J. - \ 2014
    Den Helder : IMARES (Rapport / IMARES Wageningen UR C114/14) - 123
    estuaria - effectvoorspelling - aquatische ecosystemen - waterkwaliteit - aquatische toxicologie - eems-dollard - groningen - estuaries - impact prediction - aquatic ecosystems - water quality - aquatic toxicology - eems-dollard - groningen
    MIRT-onderzoek (Meerjaren Programma Infrastructuur Ruimte en Transport) naar de ecologische verbetermogelijkheden van het Eems-Dollard estuarium in samenhang met de economische en sociale functies die het gebied vervult. Met de DPSIR methode wordt een oorzaak-gevolg keten inzichtelijk gemaakt volgens 5 elementen: Driver-Pressure-State-Impact-Response (DPSIR). Deze methode is ontwikkeld door de Europese Environment Agency.
    Samenhang in de Delta, ontwikkelingsvarianten voor de Zuidwestelijke Delta: ecologische ontwikkeling van habitats en levensgemeenschappen (deel 2)
    Ysebaert, T. ; Tangelder, M. ; Wijsman, J.W.M. - \ 2013
    Yerseke : IMARES (Rapport / IMARES Wageningen UR C159/13) - 64
    zuidwest-nederland - estuaria - aquatische ecologie - delta's - habitats - zoet water - zout water - south-west netherlands - estuaries - aquatic ecology - deltas - habitats - fresh water - saline water
    De Deltawerken brachten weliswaar veiligheid, maar daarmee verdween ook een groot deel van een zeer waardevol estuarien ecosysteem. Het oorspronkelijk stelsel van estuaria veranderde in een serie van elkaar gescheiden waterbekkens. Zoet en zout water zijn in de huidige situatie grotendeels gescheiden. Alleen de Westerschelde behield het karakter van een estuarium. Voorliggende rapportage geeft inzicht in de ecologische potenties van verschillende ontwikkelingsvarianten voor de Zuidwestelijke Delta (ZW Delta) als geheel en voor de verschillende waterbekkens binnen de ZW Delta. Hierbij gaat het om de ecologische potenties binnen de buitendijkse gebieden. In een eerdere studie, (IMARES, 2013), is een ecologische indeling ontwikkeld van systeem- en habitattypen die gebruikt kan worden om de verschillende ontwikkelvarianten op een gestandaardiseerde manier met elkaar te vergelijken. Voorliggende studie betreft de vervolgstap waarin een analyse is uitgevoerd naar het potentieel voorkomen van habitats en daarbij horende levensgemeenschappen in de verschillende ontwikkelvarianten
    River flow controls on tides an tide-mean water level profiles in a tidel freshwater river
    Sassi, M.G. ; Hoitink, A.J.F. - \ 2013
    Journal of Geophysical Research: Oceans 118 (2013)9. - ISSN 2169-9275 - p. 4139 - 4151.
    wavelet transform - salmonid habitat - mahakam delta - discharge - propagation - estuaries - channels - friction - impacts - cycles
    [1] Tidal rivers feature oscillatory and steady gradients in the water surface, controlled by interactions between river flow and tides. The river discharge attenuates the tidal motion, and tidal motion increases tidal-mean friction in the river, which may act as a barrier to the river discharge. Time series of tidal water level amplitudes at five gauge stations along the River Mahakam in Indonesia, and tidal flow velocity amplitudes at a discharge monitoring station were obtained applying wavelet analysis. Temporal variations in tidal damping coefficients for quaterdiurnal, semidiurnal, and diurnal tidal species were quantified from the observed amplitude profiles. The analysis shows that tidal damping during the rising limb of a discharge wave differs from damping during the falling limb. Wavelet cross-correlations between surface levels yielded empirical estimates of wave numbers. An empirical relation between tidal damping and river flow is derived to describe subtidal bottom friction along an idealized tidal river resembling the Mahakam. The subtidal friction is decomposed into contributions from the river flow only, from river-tide interaction, and from tidal asymmetry. Even for high river flow and low tidal velocity, river flow enhances friction attributed to river-tide interaction, causing subtidal water level setup. A simple multilinear regression model using subtidal bottom friction is employed to predict subtidal water levels at locations upstream, with a relatively good agreement between predictions and observations. The explicit expression shows the nonlinear dependence of subtidal friction on river flow velocity, explaining the complex behavior of tidal-mean surface level profiles.
    Water and suspended sediment division at a stratified tidal junction
    Buschman, F.A. ; Vegt, M. van der; Hoitink, A.J.F. ; Hoekstra, P. - \ 2013
    Journal of Geophysical Research: Oceans 118 (2013)3. - ISSN 2169-9275 - p. 1459 - 1472.
    lateral circulation - river discharge - residual flows - estuaries - channel - curvature - bay - fronts - driven - delta
    [1] Tidal junctions play a crucial role in the transport of water, salt, and sediment through a delta distributary network. Water, salt and sediment are exchanged at tidal junctions, thereby influencing the transports in the connecting branches and the overall dynamics of the system. This paper presents observations of water, salt and sediment transports in three channels that connect at a stratified tidal junction. Flow variation in one channel was found to lag behind flow variation in a connected channel by more than 1¿h, which is largely attributed to channel length differences from the junction to the sea. The water columns in the three channels were periodically stratified during spring tide, whereas the salinity structure represented a salt wedge during neap tide. Salinity differences between the three channels were substantial. The channels contain water bodies of different salinity and act largely independently. Flow velocities in the upper and lower layers differed substantially. Flow in the lower layer was generally in the direction of acceleration produced by the baroclinic pressure gradient. Interestingly, baroclinic pressure gradients were sometimes directed landward, indicating the presence of saltier water at the land side of the estuary. In sharp channel bends close to the junction, secondary flow was strongest at the highest axial flow velocity during spring tide. In one channel bend, these circulations steered the suspended sediment toward the inner bend, which affected the suspended sediment division.
    Energiehuishouding van steltlopers en de effecten van verandering in foerageer-oppervlak op populaties: Studie uitgevoerd in het kader van ANT-Ooscerschelde & LTV-Natuurlijkheid
    Schellekens, T. ; Ens, B.J. ; Ysebaert, T. - \ 2013
    Yerseke : IMARES (Rapport / IMARES nr. C 067/13) - 26
    watervogels - foerageren - estuaria - oppervlakte (areaal) - oosterschelde - westerschelde - energiebalans - waterfowl - foraging - estuaries - acreage - eastern scheldt - western scheldt - energy balance
    Er doen zich grootschalige morfologische veranderingen voor in de Zuidwestelijke Delta: in de Oosterschelde t.g.v. de zandhongerproblematiek, en in de Westerschelde ten gevolge van de vaarwegverruiming. In beide watersystemen leiden deze processen tot een verandering van het areaal droogvallende platen en slikken (met als gevolg veranderingen in voedselbeschikbaarheid en beschikbare foerageertijd). Deze intergetijdengebieden zijn belangrijke foerageergebieden voor steltlopers. De energiehuishouding (het verschil tussen opname en verbruik van energie) van steltlopers speelt een belangrijke rol in de bepaling van de effecten van dergelijke veranderingen op steltlopers. Voor beide gebieden gelden N200 instandhoudingsdoelstellingen voor steltlopers
    Final report on impact of catchment scale processes and climate change on cause-effect and recovery-chains
    Verdonschot, P.F.M. ; Keizer-Vlek, H.E. ; Spears, B. ; Brucet, S. ; Johnson, R. ; Feld, C. ; Kernan, M. - \ 2012
    Brussel : European Commission - 116
    ecologisch herstel - beheer van waterbekkens - rivieren - meren - estuaria - kustwateren - degradatie - biologische indicatoren - verzuring - eutrofiëring - morfologie - ecologische beoordeling - ecological restoration - watershed management - rivers - lakes - estuaries - coastal water - degradation - biological indicators - acidification - eutrophication - morphology - ecological assessment
    Catchment wide integrated basin management requires knowledge on cause-effect and recovery chains within water bodies as well as on the interactions between water bodies and categories. In the WISER WP6.4 recovery processes in rivers, lakes and estuarine and coastal waters were evaluated. The major objectives were: - to analyse and compare (cause-effect and) recovery chains within water categories based on processes and structural and functional features; - to detect commonalities among different chains in different water categories ( to compare recovery chains between water categories); - to link recovery chains to over-arching biological processes and global change; - to develop a method to combine recovery effects in a summarising ‘catchment’ metric. The main stressors studied to reach these objectives were acidification, eutrophication and hydromorphological changes.
    N2000 habitas in 2011
    Sluis, Christiaan van - \ 2012
    aquatic ecology - natura 2000 - estuaries - eastern scheldt - western scheldt - grevelingen
    Ecologische veerkracht
    Tangelder, Marijn - \ 2012
    resilience of nature - ecology - biodiversity - estuaries - south-west netherlands
    Downstream hydraulic geometry of a tidally influenced river delta
    Sassi, M.G. ; Hoitink, A.J.F. ; Brye, B. de; Deleersnijder, E. - \ 2012
    Journal of Geophysical Research: Earth Surface 117 (2012). - ISSN 2169-9003 - 13 p.
    sediment transport - mahakam delta - flow - estuaries - discharge - model - tides - propagation - channels - bifurcations
    Channel geometry in tidally influenced river deltas can show a mixed scaling behavior between that of river and tidal channel networks, as the channel forming discharge is both of river and tidal origin. We present a method of analysis to quantify the tidal signature on delta morphology, by extending the hydraulic geometry concept originally developed for river channel networks to distributary channels subject to tides. Based on results from bathymetric surveys, a systematic analysis is made of the distributary channels in the Mahakam Delta (East Kalimantan, Indonesia). Results from a finite element numerical model are used to analyze the spatial variation of river and tidal discharges throughout the delta. The channel geometry of the fluvial distributary network scales with bifurcation order, until about halfway the radial distance from the delta apex to the sea. In the seaward part of the delta, distributary channels resemble funnel shaped estuarine channels. The break in morphology, which splits the delta into river- and tide-dominated parts, coincides with a break in the ratio between tidal to fluvial discharges. Downstream hydraulic geometry exponents of the cross-sectional area show a transition from the landward part to the seaward part of the delta. The numerical simulations show that the tidal impact on river discharge division at bifurcations increases with the bifurcation order, and that the variation of river discharge throughout the network is largely affected by the tides. The tidal influence is reflected by the systematic variation of downstream hydraulic geometry exponents.
    Ecologische begrippen: veerkracht en verwante begrippen in het kader van Beleid Ondersteuning Programmabureau Zuidwestelijke Delta
    Tangelder, M. ; Troost, K. ; Ende, D. van den - \ 2012
    Yerseke : IMARES (Rapport / IMARES Wageningen UR C068/12) - 33
    biodiversiteit - estuaria - veerkracht van de natuur - aquatische ecologie - zuidwest-nederland - biodiversity - estuaries - resilience of nature - aquatic ecology - south-west netherlands
    De term ”veerkracht” of “ecologische veerkracht” wordt met toenemende mate gebruikt als een gewenste eigenschap van een deltasysteem. Maar wat is ecologische veerkracht precies en wanneer is een systeem veerkrachtig? Dit zijn centrale vragen in dit rapport, die een eerste aanzet is om de betekenis van het concept ecologische veerkracht en verwante begrippen te bediscussiëren en concretiseren.
    ANT Oosterschelde: Long-term trends of waders and their dependence on intertidal foraging grounds
    Troost, K. ; Ysebaert, T. - \ 2011
    Yerseke : IMARES (Report / IMARES Wageningen UR C063/11) - 100
    waadvogels - habitats - foerageren - natuurbescherming - natura 2000 - estuaria - oosterschelde - waders - habitats - foraging - nature conservation - natura 2000 - estuaries - eastern scheldt
    The ANT study (“Autonomous Negative Trend” of the Oosterschelde estuary) aims to deliver the scientific support needed to assess the feasibility and affordability of the different conservation goals of Natura 2000. The main aim is to advise in which locations in the Oosterschelde estuary what kind of measures can be taken in order to meet (part of) the Natura2000 conservation goals for quality and quantity of the habitat of protected shorebird species. To meet this aim we first need to get insight in how the birds use the intertidal areas, and what factors determine their presence. That we do not fully understand the autonomous trends in bird numbers is clear from a discrepancy between expected and observed trends in wader numbers. Although we would expect to see declining wader numbers because of the ongoing erosion of the intertidal, we in fact see steady and even increasing numbers of several species. The present study aims to describe and explain observed trends in bird numbers by exploring relationships between bird numbers and biotic and morphological changes in the intertidal area of the Oosterschelde estuary.
    Zoet-zoutovergangen in Nederland; stand van zaken en kansen voor de toekomst : achtergronddocument bij Natuurverkenning 2011
    Kuijs, E.K.M. ; Steenbergen, J. - \ 2011
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 259) - 62
    natuurbescherming - ecologisch herstel - estuaria - zoet water - zout water - recreatie - ecosysteemdiensten - aquacultuur - delta's - nature conservation - ecological restoration - estuaries - fresh water - saline water - recreation - ecosystem services - aquaculture - deltas
    Deze natuurverkenning voor de zoet-zoutovergangen in Nederland is onderdeel van de Natuurverkenning 2011, en heeft tot doel beleidsmakers een beeld te geven van de verschillende denkrichtingen waarmee ze beleid op kunnen stellen over hoe in de toekomst met zoet-zoutovergangen om te gaan. Er is uitgegaan van de huidige situatie, en van de problemen en kansen die in deze estuariene gebieden aanwezig zijn. Dit heeft geresulteerd in vier uitgewerkte kijkrichtingen, (vitale natuur, functionele natuur, beleefbare natuur en inpasbare natuur) waarin getracht is inzicht te geven in de manier waarop we de zoet-zoutovergangen in onze delta in 2040 zouden kunnen inrichten en gebruiken. Dit varieert van een situatie volledig gericht op het herstel en behoud van de natuur tot een situatie waarin er geen rekening wordt gehouden met de natuur. De estuaria kunnen hierbij intensiever gebruikt worden voor bijvoorbeeld vormen van aquacultuur, recreatie en visserij.
    Conflicterende of convergerende ambities in de Eems-Dollard
    Dirkx, G.H.P. ; Arnouts, R.C.M. ; Heer, M. de - \ 2011
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-paper 10) - 8
    eems-dollard - natuurwaarde - economische ontwikkeling - havens - groningen - duitsland - natuurbeheer - estuaria - eems-dollard - natural value - economic development - harbours - groningen - germany - nature management - estuaries
    Het Eems-Dollardgebied is één van de laatste nog open estuaria in Nederland. Het gebied herbergt belangrijke (internationale) natuurwaarden, maar vormt ook de toegangspoort tot havens met een grote economische betekenis voor de regio. De huidige economische ontwikkeling vraagt om voortdurende ingrepen in het estuarium. Dat zet de natuurwaarden onder grote druk. Bedrijfsleven, overheden en natuurbeschermers zoeken naar mogelijkheden om de economische en de ecologische betekenis van het gebied beter in balans te brengen. In WOt-paper 10 wordt verkend met de kijkrichtingen uit de Natuurverkenning 2010-2040 als hulpmiddel hoe dat er uit zou kunnen zien.
    Subtidal flow division at a shallow tidal junction
    Buschman, F.A. ; Hoitink, A.J.F. ; Vegt, M. van der; Hoekstra, P. - \ 2010
    Water Resources Research 46 (2010). - ISSN 0043-1397 - 12 p.
    river discharge - channel - propagation - model - stability - estuaries - impacts
    Tides influence distribution of river discharge at tidally affected channel junctions. At the apex of a channel network in an Indonesian delta, observations of flow division suggest that tidally averaged flow division depends on the tidal range. To understand the mechanisms governing the subtidal flow division, an idealized hydrodynamic junction model inspired by the observations has been set up. The barotropic model consists of two exponentially converging tidal channels that connect to a tidal river at the junction and solves the nonlinear shallow water equations. By varying the depth, length, e-folding length scale of the channel width, and hydraulic roughness in one of the two tidal channels, the sensitivity of the subtidal flow division to those four parameters was investigated. For depth, length, and e-folding length scale differences between channels the effect of tides is generally to enhance unequal subtidal flow division that occurs in the case of river flow only. In contrast, for hydraulic roughness differences, the tidal effect partly cancels the inequality in river flow division. The tidal effect may even reverse the horizontal flow circulation that would occur in the absence of tides.
    Past and future trends in nutrients export by rivers to the coastal waters of China
    Qu, H.J. ; Kroeze, C. - \ 2010
    Science of the Total Environment 408 (2010)9. - ISSN 0048-9697 - p. 2075 - 2086.
    phosphorus transport - continental shelves - nitrogen inputs - global system - consequences - estuaries - ocean - limitation - marine - carbon
    We analyzed the past and future trends in river export of dissolved and particulate nitrogen (N), phosphorus (P) and carbon (C) to the coastal waters of China, for sixteen rivers, as calculated by the Global NEWS models (Nutrient Export from WaterSheds). Between 1970 and 2000, the dissolved N and P export increased significantly, while export of other nutrients changed less. We analyzed the future trends (2000–2050) for the Millennium Ecosystem Assessment (MEA) scenarios. In general, the largest increases of dissolved nutrients export are projected for the Global Orchestration scenario, assuming a globalized world and a reactive approach toward environmental management. Future trends in river export of nutrients vary largely among basins, nutrient forms and scenarios. We calculate both increasing and decreasing trends between 2000 and 2050. We also identify the sources contributing to the nutrient export. For selected river basins we present results for alternative scenarios, which are based on the Global Orchestration scenario, but assume more environmental management. This illustrates how the NEWS models can be useful in regional analyses for decision making
    Subtidal water level variation controlled by river flow and tides
    Buschman, F.A. ; Hoitink, A.J.F. ; Vegt, M. van der; Hoekstra, P. - \ 2009
    Water Resources Research 45 (2009). - ISSN 0043-1397 - 12 p.
    probability-distribution functions - tidal analysis-methods - semi-diurnal tide - salmonid habitat - propagation - discharge - asymmetries - estuaries - impacts - areas
    Subtidal water level dynamics in the Berau river, East Kalimantan, Indonesia, feature a pronounced fortnightly variation. The daily mean water levels at a station about 60 km from the sea are 0.2–0.6 m higher during spring tide than during neap tide. To explain the underlying mechanisms, a local subtidal momentum balance is set up from field data, using continuous discharge estimates inferred from measurements taken with a horizontal acoustic Doppler current profiler. It is demonstrated that terms accounting for friction and variation in the water surface gradient are dominant in the subtidal momentum balance. To further investigate the sources of subtidal water level variation, a generic method of analysis is proposed to decompose the subtidal friction term into contributions caused by river flow, by interaction between tidal motions and river flow, and by the tidal motions alone. At the station under study, mainly the river-tide interaction term is responsible for generating fortnightly variation of the subtidal water level. The contribution from interaction between diurnal, semidiurnal, and quarterdiurnal tides to subtidal friction is significantly smaller. Provided that the reduction of tidal velocity amplitudes with increasing discharges can be predicted from a regression model, the results presented herein can be used to predict changes in subtidal water levels as a result of increased river discharges.
    Trends in Wadden Sea Fish Fauna, Part I: Trilateral Cooperation
    Bolle, L.J. ; Neudecker, T. ; Vorberg, R. ; Damm, U. ; Diederichs, B. ; Jager, Z. ; Scholle, J. ; Daenhardt, A. ; Luerssen, G. ; Marencic, H. - \ 2009
    IJmuiden : IMARES (Report / Wageningen IMARES C108/08) - 69
    vissen - soorten - onderzoek - karteren - kustgebieden - estuaria - waddenzee - fishes - species - research - surveying - coastal areas - estuaries - wadden sea
    The shallow waters of the Wadden Sea and the connected estuaries and coastal waters provide indispensable habitats for a whole range of fish species in the course of their life-cycle. These areas provide spawning, feeding and nursery grounds and serve as transit route for diadromous species migrating between marine and fresh water habitats. Environmental changes (e.g. climate change) and anthropogenic pressures (e.g. fisheries) will likely result in changes in the abundance and species composition of the fish fauna in the Wadden Sea. An overview of fish monitoring programs carried out in the Wadden Sea revealed 2 mayor limitations. Firstly, the spatial coverage of surveys targeting pelagic species is limited. Secondly, the seasonal coverage of the beam trawl surveys is limited. Improved spatial and seasonal coverage will provide more insight in the dynamics of fish populations in the Wadden Sea.
    Primary production and eddy correlation measurements of CO2 exchange over an intertidal estuary
    Zemmelink, H.J. ; Slagter, H.A. ; Slooten van, C. ; Snoek, J.W. ; Heusinkveld, B.G. ; Elbers, J.A. ; Bink, N.J. ; Klaassen, W. ; Philippart, C.J.M. ; Baar, H. de - \ 2009
    Geophysical Research Letters 36 (2009)19. - ISSN 0094-8276 - 5
    mariene gebieden - waterkwaliteit - primaire productie - kooldioxide - waddenzee - noordzee - estuaria - broeikasgassen - marine areas - water quality - primary production - carbon dioxide - wadden sea - north sea - estuaries - greenhouse gases - gas transfer velocity - continental-shelf - carbon-dioxide - sea - ocean - fluxes - variability - scheldt - budget - flow
    Field measurements by eddy correlation indicate an average CO2 uptake of 1.9 g C m-2 d-1 by the intertidal Wadden Sea estuary in spring 2008. The flux did not show a dependency on the tide and fluxes during high and low tide were comparable. We hypothesize that biological production in the water column and in microbial mats that cover sediments lead to an undersaturation of CO2 that is strong enough to support the observed fluxes. The total carbon uptake by this intertidal estuary from day of the year 101–168 is estimated to be -1.7 Tg C. Extrapolation of this flux over three months in spring suggests that the uptake of CO2 by this estuary over this period is comparable to 24% of the yearly carbon flux over the North Sea and the European estuaries
    Profieldocument Habitattype 1130 Estuaria
    Imares, - \ 2008
    habitats - estuaries - deltas - eems-dollard - western scheldt
    Werken aan deltanatuur: compenseren of versterken?
    Groenendijk, F.C. - \ 2008
    IJmuiden : IMARES (IMARES nr. C038/08) - 13
    aquatische ecologie - natuurwaarde - natuurtechniek - estuaria - ecologische beoordeling - eilanden - natuurcompensatie - kustgebieden - westerschelde - oosterschelde - kustbeheer - aquatic ecology - natural value - ecological engineering - estuaries - ecological assessment - islands - nature compensation - coastal areas - western scheldt - eastern scheldt - coastal management
    De Deltacommissie heeft IMARES om een expert-opinie gevraagd omtrent mogelijkheden om in de buitendelta van de Wester- en Oosterschelde ecologische waarden te versterken of te creëren als antwoord op verlies van ecologische waarden binnen die estuaria. Met name is gevraagd een ecologische beoordeling te geven van de creatie van een eiland op de Vlakte van de Raan. IMARES heeft zich over de vraagstelling gebogen met een aantal experts. Daarbij is de vraag breder getrokken dan alleen een eiland.
    Gezondheidsindicatoren voor het Schelde estuarium : een inventarisatie en evaluatie van biologische graadmeters voorgesteld in nationale en internationale kaders, toegepast op het Nederlandse deel van het Schelde-estuarium
    Craeymeersch, J.A.M. ; Mesel, I.G. de; Goudswaard, P.C. ; Heessen, H.J.L. ; Henkens, R.J.H.G. ; Jongbloed, R.H. ; Kaag, N.H.B.M. - \ 2008
    Yerseke : IMARES (Rapport / Wageningen IMARES C020/08) - 65
    estuaria - waterkwaliteit - biologische indicatoren - monitoring - eu regelingen - kaderrichtlijn water - natura 2000 - natuurgebieden - westerschelde - estuaries - water quality - biological indicators - monitoring - eu regulations - water framework directive - natura 2000 - natural areas - western scheldt
    In dit rapport is een inventarisatie gemaakt van de parameters die worden benut in het kader van een aantal Europese richtlijnen (water, natura 2000) en nationaal beleid (ecologische hoofdstructuur) aangevuld met parameters voorgesteld door het Milieu en Natuurplanbureau. Deze zijn vervolgens beorrdeeld op de bruikbaarheid als graadmeters vor deze gezondheidstoestand. Conclusie is dat de meeste graadmeters die zijn opgesteld, ook voor het Schelde estuarium bruikbaar zijn.
    Least-inference methods for constructing networks of trophic flows
    Ulanowicz, R.E. ; Scharler, U.M. - \ 2008
    Ecological Modelling 210 (2008)3. - ISSN 0304-3800 - p. 278 - 286.
    ecosystem attributes - environ analysis - bay ecosystem - steady-state - dynamics - estuaries
    The construction of material and energy budgets within ecosystems has long been accomplished via manual calculation. Recently, optimization techniques have been adapted to automate the procedure, but these methods require assumptions that may not square with biological reality. Two algorithms are developed to construct ecosystem budgets under minimal inference. Although the methods do not recapitulate the model used to generate the input data, analysis reveals that the results do not differ statistically from networks that were constructed manually.
    Herstel van estuariene dynamiek in de zuidwestelijke Delta; managementsamenvatting
    Baptist, M.J. ; Mesel, I.G. de; Stuyt, L.C.P.M. ; Henkes, R. ; Molenaar, J.G. de; Wijsman, J.W.M. ; Dankers, N.M.J.A. ; Kimmel, V. - \ 2007
    Texel : IMARES (Rapport / Wageningen IMARES C119/07) - 6
    estuaria - ecologie - gebruikswaarde - effecten - aquatische ecologie - ecologisch herstel - zuidwest-nederland - estuaries - ecology - use value - effects - aquatic ecology - ecological restoration - south-west netherlands
    In deze studie wordt beschreven wat estuariene dynamiek is, worden opties voor herstel onderzocht en wordt bekeken wat de consequenties zijn voor natuur- en gebruiksfuncties. De hierin gepresenteerde varianten voor herstel richten zich op de lange-termijn en zijn projecties voor het jaar 2100.
    Creation and restoration of coastal and estuarine habitats, a review of practical examples and a description of sequential guidelines for habitat creation and restoration in port areas
    Bracke, S. ; Bucx, T. ; Frost, N. ; Jaspers, H. ; Groot, J. de; Quemeneur, G. ; Sahin, F. ; Slim, P.A. ; Slootweg, H. ; Smit, C.J. ; Swart, E. de; Tessier, T. ; Vermeersch, L. ; Vanoutrive, T. - \ 2007
    [S.l.] : NEW! Delta (New Delta thema 3 ) - 186
    kustgebieden - estuaria - habitats - natuurbescherming - havens - belgië - nederland - natura 2000 - noordwest-europa - ecologisch herstel - coastal areas - estuaries - habitats - nature conservation - harbours - belgium - netherlands - natura 2000 - northwestern europe - ecological restoration
    One of the themes of the NEW! Delta project is theme 3 "Creation and restoration of coastal and estuarine habitats" Within this theme two demonstration projects of habitat creation and restoration schemes have been implemented: one in the port of Antwerp and the other in the dune area "De Zilk" along the Dutch coast. The contributers of this study are from: ABP MER (United Kingdom), Alterra, Vlaamse overheid Afdeling Kust, DIREN Haute-Normandie, Grontmij, IMIEU Brussel, Haven van Antwerpen, Haven van Rotterdam, provincie Zuid-Holland
    Herstel van estuariene dynamiek in de zuidwestelijke Delta
    Baptist, M.J. ; Mesel, I.G. de; Stuyt, L.C.P.M. ; Henkes, R. ; Molenaar, H. de; Wijsman, J.W.M. ; Dankers, N.M.J.A. ; Kimmel, V. - \ 2007
    Texel : IMARES (Rapport / Wageningen IMARES C119/07) - 172
    estuaria - herstel - verzilting - landgebruik - landbouw - recreatie - evaluatie - aquatische ecologie - natura 2000 - estuaries - rehabilitation - salinization - land use - agriculture - recreation - evaluation - aquatic ecology - natura 2000
    Dit rapport bevat de resultaten van een studie naar herstel van estuariene dynamiek in de Delta. In deze studie wordt beschreven wat estuariene dynamiek is, worden opties voor herstel onderzocht en wordt bekeken wat de consequenties zijn voor natuur en gebruiksfuncties. De hierin gepresenteerde varianten voor herstel richten zich op de lange termijn en zijn projecties voor het jaar 2100
    Literature review of available techniques to characterize marine and estuarine food webs; with emphasis for application in the model OMEGA
    Lange, H.J. de; Brink, N.W. van den - \ 2006
    Wageningen : Alterra (Alterra-rapport 1372) - 55
    voedselwebben - ecologie - marien milieu - estuaria - karakterisering - modellen - merkers - food webs - ecology - marine environment - estuaries - characterization - models - markers
    Food webs can be characterized by use of markers. These are increasingly used in food web studies since they are the only tool that can be used to infer relations through multiple trophic levels. Such a marker is a characteristic of an organism that can be objectively measured and evaluated as an indicator of normal biologic processes. These include fatty acids, stable isotopes, and molecular markers such as immunological markers and DNA markers. This report presents the results of a literature survey on these marker techniques, their use in describing marine and estuarine food webs, and an evaluation of their usefulness for the model OMEGA. Stable isotope analysis is advised as the best method to characterize food webs by means of trophic position and carbon source. Fatty acids can be used to differentiate within trophic groups, especially within the group of primary producers.
    Ecologische en bestuurlijk-juridische argumenten voor een integraal kustzonebeleid en -beheer in Nederland; "een amfibische benadering"
    Klijn, J.A. ; Apeldoorn, R.C. van; Dankers, N.M.J.A. - \ 2006
    Wageningen : Alterra (Alterra-rapport 1293) - 125
    kustgebieden - estuaria - kusten - duinen - bedrijfsvoering - noordzee - ecologie - wetgeving - milieubeleid - nederland - zeeniveau - coastal areas - estuaries - coasts - dunes - management - north sea - ecology - legislation - environmental policy - netherlands - sea level
    In opdracht van RIKZ (Rijks Instituut voor Kust en Zee) is verkend welke ecologische en bestuurlijk-juridische inzichten gehanteerd kunnen worden op weg naar een meer geïntegreerd kustbeheer, waarbij zowel de landgedeelten als de ondiepe wateren in samenhang worden beschouwd ten dienste van een duurzame bestemming, inrichting en beheer. Ruimte-en tijdschalen van kusten en kustprocessen, maar ook de “span of control” van overheden zijn belangrijk. Gekeken is naar actuele en toekomstige ontwikkelingen, die een integrale aanpak vragen. Op grond van de analyse is aangegeven wat hoofd- en bijzaken zijn, waar kansen liggen voor verbetering van de ecologische situatie en wat bestuurlijk gezien gedaan kan worden om beleidsvoornemens effectief en efficiënt te kunnen realiseren. Voor integraal kustzonebeheer worden voorstellen gedaan
    Toxicological profiling of sediments with in vitro mechanisms-based bioassays for endocrine disruption
    Houtman, C.J. ; Cenijn, P.H. ; Hamers, T. ; Lamoree, M.H. ; Legler, J. ; Murk, A.J. ; Brouwer, A. - \ 2004
    Environmental Toxicology and Chemistry 23 (2004)1. - ISSN 0730-7268 - p. 32 - 40.
    biotesten - sediment - toxiciteit - hormonen - estuaria - rivieren - nederland - hormoonverstoorders - waterbodems - ecotoxicologie - rijn - maas - bioassays - sediment - toxicity - hormones - estuaries - rivers - netherlands - endocrine disruptors - water bottoms - ecotoxicology - river rhine - river meuse - reporter gene assays - estrogenic activity - aromatic-hydrocarbons - human transthyretin - expression assays - toxic potency - extracts - chemicals - exposure - wildlife
    In vitro bioassays are valuable tools for screening environmental samples for the presence of bioactive (e.g., endocrine-disrupting) compounds. They can be used to direct chemical analysis of active compounds in toxicity identification and evaluation (TIE) approaches. In the present study, five in vitro bioassays were used to profile toxic potencies in sediments, with emphasis on endocrine disruption. Nonpolar total and acid-treated stable extracts of sediments from 15 locations in the Rhine Meuse estuary area in The Netherlands were assessed. Dioxin-like and estrogenic activities (using dioxin-responsive chemical-activated luciferase gene expression [DR-CALUX] and estrogen-responsive chemical-activated luciferase gene expression [ER-CALUX] assays) as well as genotoxicity (UMU test) and nonspecific toxic potency (Vibrio fischeri assay) were observed in sediment extracts. For the first time, to our knowledge, in vitro displacement of thyroid hormone thyroxine (T4) from the thyroid hormone transport protein thransthyretin by sediment extracts was observed, indicating the presence of compounds potentially able to disrupt T4 plasma transport processes. Antiestrogenic activity was also observed in sediment. The present study showed the occurrence of endocrine-disrupting potencies in sediments from the Dutch delta and the suitability of the ER- and DR-CALUX bioassays to direct endocrine-disruption TIE studies.
    Eindrapport EVA II (Evaluatie Schelpdiervisserij tweede fase) Deelproject A1: Visserij-inspanning
    Kamermans, P. ; Schuiling, E. ; Baars, J.M.D.D. ; Riet, M. van - \ 2003
    IJmuiden : RIVO (RIVO rapport nr. C057/03) - 97
    schaal- en schelpdierenvisserij - nadelige gevolgen - habitats - estuaria - waddenzee - zeeland - shellfish fisheries - adverse effects - habitats - estuaries - wadden sea - zeeland
    In het kader van de evaluatie structuurnota fase II (EVA II) is informatie nodig over de omvang van de schelpdiervisserij-activiteiten in Waddenzee en Zeeuwse Delta, de wijze van vissen, de vangsten, de locatie van vissen en de bodemberoering. Dit rapport heeft vooral een beschrijvend karakter
    Ecologisch profiel van de Japanse oester
    Kater, B.J. - \ 2003
    IJmuiden : RIVO (Rapport / RIVO nr. C032/03) - 32
    oesters - crassostrea gigas - habitats - estuaria - oosterschelde - oysters - crassostrea gigas - habitats - estuaries - eastern scheldt
    Een van de onderdelen binnen EVA II is het voedselreserveringsbeleid in de Oosterschelde. Binnen het deelproject zijn vragen gesteld omtrent de ontwikkeling van vogel- en kokkelpopulaties. Een van de onderdelen van het onderzoek moet antwoord geven op de vraag in hoeverre de Japanse oester Crassostrea gigas de ontwikkeling van de kokkelbestanden heeft beïnvloed. Daartoe is een ecologisch profiel van de Japanse oester opgesteld. In dit profiel wordt de bekende literatuur omtrent de ecologie van de Japanse oester gebundeld.
    Europese delta-landschappen; een verkenning naar de gemeenschappelijke problematiek in Europese delta's, de mogelijkheden om in Interreg-programma's te participeren en de bereidheid van partners om samen te werken in initiatieven
    Schröder, R.R.G. ; Steekelenburg, M.G.N. van; Wijermans, M.P. ; Blom, G.E. ; Hondt, F. D' - \ 2003
    Wageningen : Alterra (Alterra-rapport 700) - 51
    delta's - estuaria - europa - nederland - landschapsbescherming - bedrijfsvoering - coöperatieve onderhandeling - vennootschappen - beleid - deltas - estuaries - europe - netherlands - landscape conservation - management - cooperative bargaining - partnerships - policy
    Op verzoek van de Rijn-Scheldedelta heeft Alterra in samenwerking met O2 Consult een onderzoek gedaan naar de mogelijkheden voor regionale samenwerkingsprojecten binnen de Europese Interreg-fondsen tussen de Rijn-Scheldedelta en ander Europese regio's. Hiertoe is eerst een landschappelijke analyse van de Rijn-Scheldedelta, andere deltagebieden en vergelijkbare landschappen gedaan. Dit rapport vormt de weerslag van zowel de analyse als de zoektocht naar partners.
    Een eerste indicatie van mogelijkheden en knelpunten bij het realiseren van een geleidelijke zout-zoet overgang in het Balgzandkanaal
    Wintermans, G. ; Dankers, N.M.J.A. - \ 2003
    Wageningen : Alterra (Alterra-rapport 685) - 31
    waterbeheer - kanalen - zout water - zoet water - brakwater - estuaria - vismigratie - vissen - sluizen - noord-holland - waterstand - water management - canals - saline water - fresh water - brackish water - estuaries - fish migration - fishes - sluices - noord-holland - water level
    In Nederland wordt de overgang tussen het zoete en zoute water op de meeste plaatsen gekenmerkt door een plotselinge verandering in plaats van een gradiënt. Bijna overal liggen dijken, spuisluizen of gemalen. Karakteristieke brakke gebieden en mogelijkheden voor vismigratie zijn daardoor verloren gegaan. Vanuit verschillende ministeries wordt gestreefd naar anders omgaan met water en bij dat beleid neemt het herstel van zoet-zoutgradiënten een belangrijke plaats in. Door de lage ligging, onder het hoogwaterniveau van de zee, van het overgrote deel van het Nederlandse kustgebied zijn natuurlijke overgangen nauwelijks te realiseren. Door slim gebruik te maken van spuimiddelen zijn er wellicht wel mogelijkheden om redelijk natuurlijke situaties te scheppen. In de kop van Noord-Holland lijkt een mogelijkheid aanwezig die nadere uitwerking en studie zou verdienen.
    Vegetation change in a man-made salt marsh affected by a reduction in both grazing and drainage
    Esselink, P. ; Fresco, L.F.M. ; Dijkema, K.S. - \ 2002
    Applied Vegetation Science 5 (2002)1. - ISSN 1402-2001 - p. 17 - 32.
    drainage - plantengemeenschappen - zoutmoerassen - vegetatiekartering - wetlands - estuaria - begrazing - eems-dollard - ecologie - kwelder - natuurontwikkeling - ontwatering - vegetatie - drainage - grazing - plant communities - vegetation mapping - mapping - wetlands - estuaries - eems-dollard
    Distribution, speciation and bioavailability of Lanthanides in the Rhine-Meuse estuary, The Netherlands
    Moermond, C.T.A. ; Tijink, J. ; Wezel, A.P. van; Koelmans, A.A. - \ 2001
    Environmental Toxicology and Chemistry 20 (2001)9. - ISSN 0730-7268 - p. 1916 - 1926.
    rivieren - estuaria - zeldzame aardelementen - biologische beschikbaarheid - chemische speciatie - distributie - nederland - rijn - maas - aquatische ecosystemen - rivers - estuaries - rare earth elements - bioavailability - chemical speciation - distribution - netherlands - river rhine - river meuse - aquatic ecosystems
    Changing environmental conditions may influence the fate and bioavailability of lanthanides (part of the rare earth elements [Ln]) in estuaries. The aim of this study was to quantify the variation in estuarine lanthanide solid/water distribution, speciation, and bioaccumulation. The latter was studied in the amphipod Corophium volutator under field and laboratory conditions. Calculations with the chemical equilibrium model MINEQL indicate that dissolved lanthanides are complexed mainly to carbonates and dissolved organic matter. In the water phase, the relative abundance of the free ion, LnCO3, and humic complexes decreases from lanthanum to lutetium, whereas the relative abundance of Ln(CO3)2 increases. Cerium and europium anomalies were found in the water. Europium anomalies were also found in some biota. The biota sediment accumulation factors (BSAFs) decreased across the series from lanthanum to lutetium. Regression analysis revealed that alkalinity correlated negatively with lanthanide uptake. This suggests that increasing complexation reduced bioavailability under the prevailing conditions. The BSAFs did not depend on salinity or pH, which may simplify sediment-quality criteria for fresh versus saline waters. Field BSAFs were significantly lower than laboratory values for the same sediments, which is explained by adaptation of the organisms to lanthanides.
    Ontwikkeling van de biomassa van het microfytobenthos in het Eems-Dollard estuarium in de periode 1992-1999
    Boer, W.F. de - \ 2000
    Haren : Koeman & Bijkerk - 66
    benthos - waterplanten - biomassa productie - habitats - estuaria - nederland - primaire productie - groningen - eems-dollard - aquatic plants - biomass production - estuaries - netherlands - primary production
    Functionele biodiversiteit in estuaria; natuurlijke zuivering
    Dankers, N.M.J.A. ; Brinkman, A.G. ; Duin, W.E. van; Dijkema, K.S. - \ 1999
    In: Biodiversiteit en natuurlijke zuivering in oppervlaktewater : een literatuurstudie naar de stand van de wetenschap / Ietswaart, T., Hersbach, J., - p. 87 - 131.
    kustgebieden - estuaria - waterzuivering - sediment - biodiversiteit - ecosystemen - nederland - aquatische ecosystemen - natuur - waddenzee - coastal areas - estuaries - water treatment - sediment - biodiversity - ecosystems - netherlands - aquatic ecosystems - nature - wadden sea
    Intertidal deposits: river mouths, tidal flats, and coastal lagoons
    Eisma, D. ; Boer, P.L. de; Cadee, G.C. ; Dijkema, K. ; Ridderinkhof, H. ; Phillippart, C. - \ 1998
    Boca Raton : CRC - ISBN 9780849380495 - 525
    kustgebieden - kustvlakten - kustwateren - geologische sedimentatie - mariene sedimenten - estuaria - lagunes - geomorfologie - wadden - coastal areas - coastal plains - coastal water - geological sedimentation - marine sediments - estuaries - lagoons - geomorphology - tidal flats
    Intertidal Deposits: River Mouths, Tidal Flats, and Coastal Lagoons combines the authors personal and professional experience with the mass of available literature to present a cohesive overview of intertidal deposits and the widely diverse conditions of their formation worldwide. This includes the strong influence of water movements, climate, sediment particle characteristics, vegetation, fauna, and man. Intertidal areas are important for many reasons both scientifically and economically and recently, a growing concern for conservation of these fragile regions strives to preserve and protect their natural balance. This book, written by an international expert in the field, concentrates on the more important intertidal areas distinguished by size and morphology, tidal range, the degree and type of vegetational cover, the amount and type of benthic fauna, the extent of human exploitation, and the degree of previous study. Discusses the more important intertidal areas, subdivided by tidal range. Includes a series of chapters on the morphology of intertidal areas (including channels and creeks), the composition and structures of intertidal sediments, the processes of sediment transport, deposition and erosion, and the influence of intertidal flora and fauna. Presents separate sections on benthic fauna and microflora, saltmarshes, mangroves, and algal mats and seagrasses. Addresses the influence of man on existing intertidal areas. Provides a short chapter on the Holocene history of intertidal areas.
    Aantalsfluctuaties van enige niet commerciële vissoorten in het Schelde estuarium en de Voordelta, 1987-1995
    Jong, P.D. de - \ 1997
    IJmuiden etc. : DLO-Rijksinstituut voor de Visserijonderzoek (RIVO rapport nr. C024/97) - 27
    vissen - soorten - estuaria - nederland - voordelta - fishes - species - estuaries - netherlands - voordelta
    Hydrodynamics, sediment transport and light extinction off Cape Bolinao, Philippines
    Rivera, P.C. - \ 1997
    Agricultural University. Promotor(en): L. Lijklema; W. van Vierssen. - Rotterdam : Balkema - ISBN 9789054104087 - 244
    delta's - estuaria - hydraulica - hydrodynamica - rivieren - waterlopen - kanalen - water - geologische sedimentatie - kusten - modellen - theorie - onderzoek - oceanografie - deltas - estuaries - hydraulics - hydrodynamics - rivers - streams - canals - water - geological sedimentation - coasts - models - theory - research - oceanography

    Observational and numerical modelling studies of the hydrodynamics, sediment transport, and light extinction were undertaken in the marine environment around Cape Bolinao in the Lingayen Gulf (Northwest Philippines). Abundant with ecologically important seagrasses and benthic organisms, Cape Bolinao is presently threatened with siltation and eutrophication problems. For this reason intensive field measurements of relevant enviromnental variables which include currents, tides, temperature, salinity, total suspended solids (TSS), ash-free dry weight (AFDW), sedimentation flux, grain size distribution and organic content of bottom sediments, gilvin absorption, phytoplankton concentration, and light extinction were executed from August 1993 to June 1995. Laboratory experiments were simultaneously undertaken to determine the sedimentation and light extinction characteristics of various sediment fractions. Using time series and regression analyses, the results were analyzed and presented. A set of numerical models were developed and applied in the area around Cape Bolinao and the Lingayen Gulf. A prognostic model for the hydrodynamics, driven by realistic wind and tide forces, was developed independently for the cape (fine-resolution model) and the gulf (coarse resolution model). An operational open boundary condition based on the method of wave propagation is discussed. The hydrodynamical predictions were used, in conjunction with a diagnostic surface wave model, to force the suspended sediment transport model. The transport model, which is based on the time-dependent advection-diffusion equation, is third order accurate in space and time. For a realistic description of the suspended sediment transport process in Cape Bolinao, resuspension and sedimentation fluxes were included in the numerical model using existing parameterizations. The predicted suspended sediment concentrations were used in a diagnostic model for light extinction. This later model is based on the assumption that the contributions of the optically active components to the attenuation of the photosynthetically available radiation (PAR) are linearly additive. Calibration of the numerical models using field observations produced a set of parameter values which is deemed representative for the area of investigation. Using these parameter values, the overall model predictions were in good agreement with field observations. Finally, using the integrated model, the impact of river sediment loads (treated as a conservative tracer) in the Bolinao reef system was quantified.

    Het fenomeen delta : landschap van Nico de Jonge = The phenomenon Delta : a Nico de Jonge's landscape
    Boekhorst, J.K.M. te; Deroose, P. ; Harsema, H. ; Illés, V. ; Jonge, N. de - \ 1996
    Wageningen : Blauwdruk - ISBN 9789075271034 - 82
    plattelandsplanning - plattelandsontwikkeling - landgebruik - bedrijfsvoering - landschap - landschapsbouw - ruimtelijke ordening - landbouwgrond - estuaria - nederland - belgië - cultuurlandschap - wadden - rural planning - rural development - land use - management - landscape - landscaping - physical planning - agricultural land - estuaries - netherlands - belgium - cultural landscape - tidal flats
    Nico M. De Jonge, emeritus hoogleraar landschapsarchitectuur aan de Landbouwuniversiteit Wageningen, heeft een belangrijk deel van zijn leven gewijd aan de vormgeving van landschappen in de Rijn-Scheldedelta. Het boek gaat over het unieke landschap van de delta, op de grens van land en water, van cultuur en natuur, van bestaan en verbeelding. Er wordt ingegaan op ontwikkelingen en planning aan Nederlandse en Vlaamse kant van de delta, er wordt een vergelijking gemaakt tussen deltagebieden over de wereld, en De Jonges visie op de ontwikkeling van de landschapsarchitectuur komt aan bod.
    Sulfate reduction in fine-grained sediments in the Eastern Scheldt, southwest Netherlands
    Oenema, O. - \ 1990
    Biogeochemistry 9 (1990)1. - ISSN 0168-2563 - p. 53 - 74.
    eigenschappen - estuaria - delta's - kattekleigronden - wetlands - polders - sulfaten - zeeland - schelde - waterbodems - properties - estuaries - deltas - acid sulfate soils - wetlands - polders - sulfates - zeeland - river scheldt - water bottoms
    Sulfate reduction and sulfide accumulation were examined in fine-grained sediments from rapidly accreting abandoned channels and mussel culture areas in the Eastern Scheldt, which covered 4 and 5% of the total surface area, respectively. Reduction rates were measured in batch experiments in which the SO4 2– depletion was measured during anoxic incubation. The reduction rates in summer varied between 14–68 mmol SO4 2– m–2 day–1 and were related to the sedimentation rate. In the most rapidly accreting channels, SO4 2– was exhausted below 15–50 cm and methanogenesis became the terminal process of organic carbon oxidation One-dimensional modelling of sulfate profiles in mussel banks indicated that the subsurface influx of SO4 2– was almost of the same order as the diffusive flux at the sediment-seawater interface, during the initial stages of the mussel bank accretion. The energy dissipation of waves and tidal currents on the mussel bank surface increased the apparent sediment diffusivity up to 3-fold, especially in the winter The results indicate that acid volatile sulfide (AVS) was the major, in-situ reduced, sulfur compound in the sediment. The sulfidation of easily extractable iron was nearly complete. Pyrite concentrations (40–80 M S cm–3) were as high as the AVS concentrations, but there was apparently no in-situ transformation of AVS into pyrite. The detrital pyrite originated from eroding marine sediments elsewhere
    Pyrite accumulation in salt marshes in the Eastern Scheldt, southwest Netherlands
    Oenema, O. - \ 1990
    Biogeochemistry 9 (1990)1. - ISSN 0168-2563 - p. 75 - 98.
    water - eigenschappen - estuaria - delta's - kattekleigronden - zoutmoerassen - vegetatie - wetlands - polders - pyriet - zeeland - schelde - water - properties - estuaries - deltas - acid sulfate soils - salt marshes - vegetation - wetlands - polders - pyrites - zeeland - river scheldt
    Pore water composition, pyrite distribution and pyrite crystal morphology of sediments from salt marshes in the Eastern Scheldt, southwestern Netherlands, were examined from July 1984 to October 1986. Hydrology and marsh vegetation were the chief determinants of pyrite accumulation. In the bare sediments of pans in the low marsh, highly reducing conditions prevailed just below the surface. At these sites, practically all the incoming detrital pyrite (0.5–1% FeS2) was preserved. The in-situ formation of pyrites was negligible in these anoxic sediments. All incoming detrital pyrite was oxidized in the surface layers (0–10 cm) of the medium-high marsh overgrown withSpartina anglica. Pyrite was formed at a rate of 2.6–3.8 mol S-FeS2m–2yr–1 in a narrow range of depths (15–20cm), at the interface of the oxidizing and underlying reducing sediment. At this interface the concentration profiles of Fe2 and dissolved S intersected. The role of the rhizosphere is discussed in connection with pyrite formation. No further pyrite formation occurred deeper in the sediment. This resulted in the build up of high concentrations of dissolved S and acid volatile sulfides (AVS). The decrease with depth in oxalate-extractable Fe indicated that most of the iron oxyhydroxides (70–80%) had been transformed to pyrite. Another 10–20% of oxalate-extractable Fe was present as AVS. The abundance of framboidal pyrite particles and the high concentrations of AVS and dissolved S indicated that the formation of pyrite occurred via iron monosulfide intermediates There was a linear relationship between the organic carbon and the S-FeS2 content in theSpartina overgrown reducing sediment. The mean C/S ratio was 4.2.
    Anthropogenic influences and management of estuaries.
    Wolff, W.J. - \ 1990
    Limnology and Oceanography 20 (1990). - ISSN 0024-3590 - p. 153 - 156.
    biocenose - duurzaamheid (sustainability) - natuurlijke hulpbronnen - hulpbronnengebruik - bescherming - herstel - ecologie - hydrologie - marien milieu - aquatisch milieu - estuaria - delta's - milieu - nadelige gevolgen - milieueffect - menselijke activiteit - nederland - natuurbescherming - beleid - bedrijfsvoering - aquatische ecosystemen - ecohydrologie - waddenzee - wadden - biocoenosis - sustainability - natural resources - resource utilization - protection - rehabilitation - ecology - hydrology - marine environment - aquatic environment - estuaries - deltas - environment - adverse effects - environmental impact - human activity - netherlands - nature conservation - policy - management - aquatic ecosystems - ecohydrology - wadden sea - tidal flats
    Estuariene nematoden en organische verontreiniging in de Dollard
    Romeyn, K. - \ 1988
    Texel : Rijksinstituut voor Natuurbeheer (RIN-rapport 88/62) - 23
    diergedrag - delta's - ecologie - estuaria - zoet water - gewoonten - vermenging - Nematoda - organische verbindingen - eigenschappen - zout water - water - waterverontreiniging - eems-dollard - animal behaviour - deltas - ecology - estuaries - fresh water - habits - mixing - Nematoda - organic compounds - properties - saline water - water - water pollution - eems-dollard
    The soil environment of the intertidal area in the Westerschelde Netherlands Belgium
    Oenema, O. ; Steneker, R. ; Reynders, J. - \ 1988
    Hydrobiological Bulletin 22 (1988)1. - ISSN 0165-1404 - p. 21 - 30..
    kanalen - delta's - estuaria - zoet water - geologie - zware metalen - vermenging - morfologie - nederland - rivierwater - rivieren - zout water - waterlopen - oppervlaktewater - waterverontreiniging - waterkwaliteit - biologische eigenschappen - westerschelde - zeeland - waterbodems - canals - deltas - estuaries - fresh water - geology - heavy metals - mixing - morphology - netherlands - river water - rivers - saline water - streams - surface water - water pollution - water quality - biological properties - western scheldt - zeeland - water bottoms
    hydrodynamic forces and sediment discharges determine the sedimentary environment and surface morphology of the intertidal area in the Westerschelde estuary in the S.W. Netherlands. Sandflats (clay, content < 8%) are found in the central part, mudfla
    Te verwachten ecologische effecten van pekellozing in het Eems-Dollardgebied
    Dessel, B. van - \ 1987
    Texel : RIN (RIN-rapport 87/22) - 71
    delta's - ecosystemen - estuaria - zoet water - vermenging - zout water - zoutgehalte - water - waterverontreiniging - nederland - groningen - waddenzee - deltas - ecosystems - estuaries - fresh water - mixing - saline water - salinity - water - water pollution - netherlands - groningen - wadden sea
    De milieu-effecten van lozing van ongezuiverd veenkoloniaal afvalwater in de Dollard via een persleiding
    Dankers, N. - \ 1984
    Texel : R.I.N. (RIN-rapport no. 84/2) - 12
    aquatisch milieu - afvoer - estuaria - zoet water - marien milieu - pijpleidingen - aardappelzetmeel - zout water - rioolwater - zetmeelverwerkende industrie - transport - afvalverwijdering - afvalwater - waterverontreiniging - nederland - groningen - eems-dollard - veenkolonien - aquatic environment - discharge - estuaries - fresh water - marine environment - pipelines - potato starch - saline water - sewage - starch industry - transport - waste disposal - waste water - water pollution - netherlands - groningen - eems-dollard - veenkolonien
    Systematics, ecology and feeding biology of estuarine nematodes
    Bouwman, L.A. - \ 1983
    Landbouwhogeschool Wageningen. Promotor(en): C. den Hartog, co-promotor(en): W. Wieser. - Wageningen : Bouwman - 173
    aquatisch milieu - benthos - estuaria - marien milieu - nematoda - eems-dollard - aquatic environment - benthos - estuaries - marine environment - nematoda - eems-dollard
    As part of extensive biological and chemical investigations in the Ems estuary, the nematode fauna of this area (mainly located in the sediments of tidal flats) was studied.
    First, a new method of isolating nematodes was developed, as none of the existing methods appeared to be quantitatively reliable for the isolation of organisms from silty sediments. The new method is based on differences in specific weight between nematodes (and other meiobenthos),and sediment particles: sediment samples are suspended in Ludox-TM, a colloidal silica, and, whereas organisms float to the surface of this suspension, sediment particles sink to the bottom. The isolation method can be used for either preserved or fresh sediment samples.
    In a survey of the estuary 121 nematode species were identified and during subsequent investigations 12 other species were noticed: thus, in all 133 species were identified, 4 of which were new to science. The distribution of species over the estuary was studied and the genesis of species associations was related to environmental conditions. Two main faunas were distinguished: one in the Wadden Sea part of the estuary, the other in the Dollart, both extending into the middle reaches of the estuary. In the lower sediment layers a characteristic nematode fauna was found that consisted of species that were mainly absent from the upper sediment layers It was concluded that faunal associations from the lower sediment layers originate from marine subtidal locations, whereas the associations from the upper sediment layers of tidal flats are specific to estuarine tidal environments.
    Several nematode species were cultured in agar in the laboratory and their feeding-biology was studied. From these investigations it appeared that nematodes, specific to the surface of littoral macrophytes 3 use non-selective feeding methods, consuming large amounts of bacteria, and, when their buccal cavity is large enough, also diatoms and other algae; the food organisms are ingested by means of continuous oesophageal pulsations. The interstitial nematodes, on the other hand, probably all feed selectively, oesophageal pulsations only being triggered off when a useful food organism is sensed among an overwhelming majority of similarly sized inedible particles. The larger food organisms, diatoms and other algae, protozoa, and small metazoans (including prey-nematodes) may be ingested whole or punctured and subsequently sucked out; specific buccal structures determine which consumption technique is used: when armature is absent food items are ingested whole, when armature is present food items are attacked and sucked out. Individual bacteria are probably too small for most interstitial nematodes and consequently are ignored as food.
    Special attention was focused on the ecosystem of the tidal flats close to the outfall in the southeast Dollart. It appeared that in that area the benthic ecosystem was dominated by a herbivorous food-chain, comprising diatoms and diatomconsuming nematodes (throughout the year) and oligochaetes (only in the warmer part of the year).
    It is concluded that the success of nematodes in colonizing almost all estuarine biotopes is due to their size, their sophisticated methods of food acquisition and their tolerance of environmental stress. The discharge of organic waste enhances the effects of natural gradients occurring in the estuary. The main effect is the overall decrease of species diversity and the indirect promotion of a herbivorous foodchain in which nematodes predominate the grazing fauna.

    De ecologische consequenties van het omleggen van de Eems door de Dollard
    Bergman, M. ; Dankers, N. - \ 1978
    Arnhem etc. : Rijksinstituut voor Natuurbeheer - 128
    milieu - nadelige gevolgen - milieueffect - menselijke activiteit - hydrobiologie - biocenose - waterwegen - ruimtelijke ordening - estuaria - delta's - nederland - aquatische ecosystemen - groningen - eems-dollard - environment - adverse effects - environmental impact - human activity - hydrobiology - biocoenosis - waterways - physical planning - estuaries - deltas - netherlands - aquatic ecosystems - groningen - eems-dollard
    Lijst van publikaties over het Waddengebied = List of publications on the Wadden region = Liste von Veroeffentlichungen ueber das Wattengebied
    Boekschoten, M. - \ 1975
    Leersum : R.I.N. - 191
    bibliografieën - biogeografie - plantkunde - ecologie - estuaria - geologie - hydrobiologie - natuurlijke historie - natuurbescherming - nederland - bescherming - zoölogie - aardwetenschappen - natuur - wadden - bibliographies - biogeography - botany - ecology - estuaries - geology - hydrobiology - natural history - nature conservation - netherlands - protection - zoology - earth sciences - nature - tidal flats
    Het stroomgebied van de Barito : landbouwkundige kenschets en landbouwvoorlichting
    Schophuys, H.J. - \ 1936
    Wageningen University. Promotor(en): J.E. van der Stok. - Wageningen : Veenman - 207
    hydrologie - rivieren - waterlopen - kanalen - systemen - landbouw - estuaria - delta's - stroomgebieden - drainage - geografie - regio's - reizen - beschrijvingen - nederlands indië - hydrology - rivers - streams - canals - systems - agriculture - estuaries - deltas - watersheds - drainage - geography - regions - travel - descriptions - netherlands east indies
    A description was given of the geology, topography, vegetation, climate and other characteristics of the Barito watershed in Borneo with a classification of soils and agricultural regions. For the lowlands and swamps wet rice cultivation was used as a criterion. Details were given of rice growing and its adaptation to the specific conditions of these lowlands and swamps, some of which were tidal.

    An analysis was given of the population, its composition, origin and social and economic characteristics, the relation of agricultural and cultural phases of the population, and the function and working of the agricultural advisory service. This service succeeded in restoring local institutions to organize provisional water boards and encourage wet rice cultivation. The advisory service also promoted rural handicrafts.

    More local participation was needed from the beginning in all development efforts, such as reclamation, irrigation and drainage projects, to develop self reliance and initiative. There were great opportunities for rural development even on lands earlier classified unsuitable for commercial agriculture. A soil survey of the main agricultural regions was urgently needed. 3 maps were added.

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