An assessment of the impacts of a tidal renewable energy scheme on the eutrophication potential of the Severn Estuary, UK

Authors Organisations
  • Margaret Kadiri(Author)
    Prifysgol Caerdydd | Cardiff University
  • Reza Ahmadian(Author)
    Prifysgol Caerdydd | Cardiff University
  • Bettina Bockelmann-Evans(Author)
    Prifysgol Caerdydd | Cardiff University
  • Roger A. Falconer(Author)
    Prifysgol Caerdydd | Cardiff University
  • David Kay(Author)
Type Article
Original languageEnglish
Pages (from-to)3-10
JournalComputers and Geosciences
Volume71
Early online date08 Aug 2014
DOI
Publication statusPublished - Oct 2014
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Abstract

The potential impacts of ebb-only (one-way) and flood-ebb (two-way) modes of operation of a tidal barrage on the eutrophication potential of the Severn Estuary were investigated in this study using the simple modelling approach adopted by the UK’s Comprehensive Studies Task Team (CSTT). The model predictions were compared against CSTT thresholds for assessing eutrophication in estuaries and coastal waters. For the no barrage scenario, as well as the ebb-only and flood-ebb operating modes, the estuary was found to be potentially eutrophic as the predicted equilibrium nutrient concentrations and potential maximum phytoplankton biomass chlorophyll concentrations exceeded the threshold limits. Potential maximum phytoplankton primary productivity under both ebb-only and flood-ebb operating modes were found to be noticeably higher than that for the no barrage scenario. This is believed to be due to a combination of increased water residence time and greater light availability behind the barrage. However, the conditions for phytoplankton production are likely to be more favourable under ebb-only operating mode as the potential for maximum phytoplankton primary production was found to be significantly increased under ebb-only operating mode, with largely decreased suspended particulate matter concentration compared to flood-ebb operating mode where only a small reduction in suspended particulate matter concentration is predicted.

Keywords

  • tidal barrage, eutrophication, marine renewable energy, Severn Estuary, primary production