This report presents modelling of the acoustic output of operational off-shore wind turbines and its dependence on the type of foundation structure used.
This report presents modelling of the acoustic output of operational off-shore wind turbines and its dependence on the type of foundation structure used. Three foundation types are examined: jacket, monopile and gravity foundation. The acoustic output from each of these foundation types is then compared to curves representing the hearing and behavioural response of marine species likely to come into contact with off-shore wind farms in Scottish Waters. The marine species examined are minke whales, harbour porpoise, grey seals, harbour seals, bottlenose dolphins, European eels, allis shad, sea trout and Atlantic salmon.
The modelled noise levels are likely to be audible to marine mammals particularly at 15 ms-1 when the generic wind turbines are producing maximum power. Jacket foundations generate the lowest marine mammal impact ranges compared to monopile and gravity foundations. Species with hearing specialised to low frequency, such as minke whales, may in certain circumstances detect the wind farm at least 18 km away and are the species most likely to be affected by noise from operational wind turbines. Harbour seals, grey seals and bottlenose dolphins are not considered to be at risk of displacement by the operational wind farm modelled.
Atlantic salmon and European eels are able to detect the presence of monopiles at greater ranges than gravity bases, though this may not affect their behaviour. Allis shad and sea trout appear to not be able to detect noise produced by operationalwind turbines except at close range (<100 m).
The report can be accessed through the Scottish Government website: