Offshore wind turbine construction could be putting seals' hearing at risk

Noise from pile driving during offshore wind turbine construction could be damaging the hearing of harbour seals around the UK, according to ecologists who attached GPS data loggers to 24 harbor seals while offshore wind turbines were being installed in 2012. Data on the seals' locations and their diving behaviour was combined with information from the wind farm developers on when pile driving was taking place. Models revealed that half of the tagged seals were exposed to noise levels that exceeded hearing damage thresholds.

There are currently 1,184 offshore wind turbines around the coast of the UK. The next round of construction, which began in 2014, will see hundreds more turbines installed.

"These are some of the most powerful man-made sounds produced underwater, noise capable of travelling large distances underwater," said Dr. Gordon Hastie, lead author of the Journal of Applied Ecology study. "Like most marine mammals, harbour seals have very sensitive underwater hearing at a much broader range of frequencies than humans. They probably use underwater hearing during the mating season and to detect and avoid predators. They may also rely on their hearing for navigation and finding prey."