Hydromorphological characterization of benthic habitats and species distributions in the Scheldt Estuary

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    Abstract

    within Session : Biology and ecology of coastal and estuarine systems: Evolution, adaptation and shifting baselines

    Hydromorphological characterization of benthic habitats and species distributions in the Scheldt Estuary

    Over the last decades the Scheldt Estuary has been altered by anthropogenic measures such as channel widening and enhanced wastewater treatment. At the same time, macrobenthic invertebrate abundance decreased whereas hyperbenthic (including mysid, shrimps, and decapod shrimps) and fish species reappeared in the upstream freshwater part. To assess effects of future modifications (maintain accessibility, dumping,...) on benthic species and their communities, a better understanding of the relation with hydro- and morphodynamics is necessary.
    Combining hydrodynamic and ecological modelling we have investigated the relation of benthic species and communities with morphological and hydrodynamic variables in subtidal habitats of the fresh and brackish water part of the Scheldt. Flow velocities, derived from a 2D hydrodynamic modelling, water depth, sediment characteristics and organic matter are used.
    Firstly, a multivariate analysis allowed for a distinction of a brackish and freshwater subtidal macrobenthic community. Secondly, within these salinity zones, maximum flood velocity explains the response of the benthic species and communities. This reflected in a typical high and low dynamic subtidal benthic community. Additionally hyperbenthic species preferred flood dominant areas within high dynamic areas. Based on a threshold analysis taking into account the most relevant variables, benthic and hyperbenthic community composition, a new habitat typology has been constructed. This typology provides an improved, ecologically validated instrument for monitoring and the assessment of future measures.
    Original languageEnglish
    Publication statusPublished - 9-Sep-2015

    Thematic list

    • Coast and estuaries

    EWI Biomedical sciences

    • B003-ecology

    Policy

    • decision making instruments

    Geographic list

    • Scheldt

    Technological

    • modelling

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