title: Do Changes in Current Flow as a Result of Arrays of Tidal Turbines Have an Effect on Benthic Communities?
abstract: Arrays of tidal energy converters have the potential to provide clean renewable energy for future generations. Benthic communities may, however, be affected by changes in current speeds resulting from arrays of tidal converters located in areas characterised by strong currents. Current speed, together with bottom type and depth, strongly influence benthic community distributions; however the interaction of these factors in controlling benthic dynamics in high energy environments is poorly understood. The Strangford Lough Narrows, the location of SeaGen, the world's first single full-scale, grid-compliant tidal energy extractor, is characterised by spatially heterogenous high current flows. A hydrodynamic model was used to select a range of benthic community study sites that had median flow velocities between 1.5-2.4 m/s in a depth range of 25-30 m. 25 sites were sampled for macrobenthic community structure using drop down video survey to test the sensitivity of the distribution of benthic communities to changes in the flow field. A diverse range of species were recorded which were consistent with those for high current flow environments and corresponding to very tide-swept faunal communities in the EUNIS classification. However, over the velocity range investigated, no changes in benthic communities were observed. This suggested that the high physical disturbance associated with the high current flows in the Strangford Narrows reflected the opportunistic nature of the benthic species present with individuals being continuously and randomly affected by turbulent forces and physical damage. It is concluded that during operation, the removal of energy by marine tidal energy arrays in the far-field is unlikely to have a significant effect on benthic communities in high flow environments. The results are of major significance to developers and regulators in the tidal energy industry when considering the environmental impacts for site licences.
authors: School of Natural and Built Environment, Queen's University Belfast, Belfast, Northern Ireland, BT7 1NN, United Kingdom.|Queen's University Marine Laboratory, Queen's University Belfast, (The Strand) Portaferry, Northern Ireland, BT22 1PF, United Kingdom.
authors: Louise
authors: L
authors: Kregting
authors: School of Natural and Built Environment, Queen's University Belfast, Belfast, Northern Ireland, BT7 1NN, United Kingdom.
authors: Bjoern
authors: B
authors: Elsaesser
authors: School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
authors: Robert
authors: R
authors: Kennedy
authors: School of Natural and Built Environment, Queen's University Belfast, Belfast, Northern Ireland, BT7 1NN, United Kingdom.
authors: David
authors: D
authors: Smyth
authors: School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
authors: Jack
authors: J
authors: O'Carroll
authors: Queen's University Marine Laboratory, Queen's University Belfast, (The Strand) Portaferry, Northern Ireland, BT22 1PF, United Kingdom.
authors: Graham
authors: G
authors: Savidge
mesh_terms: D000818:Animals; D044822:Biodiversity; D058448:Biota / Q000502:physiology*; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D019015:Geologic Sediments; D007091:Image Processing, Computer-Assisted; D009660:Northern Ireland; D059205:Renewable Energy; D014741:Video Recording