A new study from researchers at the universities of Exeter, Glasgow and Leeds has revealed that marine wind farms are doing more damage to gannets than previously thought.
The study focused on solely gannets and based its conclusions upon the flying height of the birds. It was thought that gannets flew at an average height of 22 metres, well below the reach from a wind turbine blade. The new research has discovered that they actually fly at around 27 metres which puts them directly into the path of wind turbines. The new findings lead the researchers to believe that the number of gannet casualties may be 12% higher than previously thought. Previous studies estimated bird height by eye or with radar but the new study used GPS tags to accurately measure the height.
This has huge implications as four wind farms are being proposed in the Firth of Forth, where the largest gannet colony in the world is located. The study suggests that birds would suffer around 1500 fatalities a year if the wind farms are not made taller. However the researchers stress their figures are based on predictions and the actually number may vary . The proposed wind farm is nearly 50km from the gannet colony, which lives on an island called the Bass Rock.
Co-author of the study Dr Ewan Wakefield suggests moving the wind turbine higher to prevent collisions; “Increasing the distance between the tips of the spinning turbine blades and the sea would give gannets more headroom – so we strongly urge that the current minimum permitted clearance turbine height be raised from 22m to 30m above sea level.”
However the wind farms have already passed through several stages of planning and so it may not be possible to alter their structure at this point.