TY - JOUR
T1 - Do Changes in Current Flow as a Result of Arrays of Tidal Turbines Have an Effect on Benthic Communities?
AU - Kregting, Louise
AU - Elsaesser, Bjoern
AU - Kennedy, Robert
AU - Smyth, David
AU - O'Carroll, Jack
AU - Savidge, Graham
PY - 2016/8/25
Y1 - 2016/8/25
N2 - 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.
AB - 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.
U2 - 10.1371/journal.pone.0161279
DO - 10.1371/journal.pone.0161279
M3 - Article
SN - 1932-6203
VL - 11
JO - PLoS ONE
JF - PLoS ONE
IS - 8
M1 - e0161279
ER -