Offshore wind farm construction noise can displace harbour porpoises

Source: Science for Environment Policy

Noise caused by construction of Germany’s first offshore wind farm caused significant habitat disturbance for harbour porpoises, according to a recent study. Its results suggest that porpoises avoided areas up to 20 kilometres from the noise source during construction of the wind farm’s foundations.

Development of offshore wind farms plays a major role in the shift towards renewable energies. The construction of Germany’s first offshore wind farm began in the North Sea in September 2008. Offshore wind turbines require solid foundations; typically these are made of heavy posts driven into the seabed with a hydraulic hammer, a process known as pile-driving. With each hammer impact, energy is transmitted into the surrounding water as sound. Sound that causes negative effects, in this context, is referred to as ‘noise’.

Manmade marine noise has been found to have negative effects on some species, such as cetaceans (whales, dolphins, and porpoises), including hearing damage and displacement. Germany has only one resident cetacean, the harbour porpoise, a species considered particularly vulnerable to disturbance, injury or death from human activity. Marine noise is one of these disturbances, potentially capable of damaging hearing and driving away prey species that harbour porpoises feed upon.

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