Underwater Noise Monitoring at an Operational Nearshore Wind Farm: First Results from the SWIM Project

Offshore wind energy is growing rapidly, as are concerns about the risks to marine species from underwater noise associated with it. The SWIM project aims to better understand and predict these impacts by monitoring an existing wind farm in the Gulf of Taranto (Italy). This work reports the first results obtained from analysing data acquired during the project’s surveys. Several natural and anthropogenic factors contribute to the Sound Pressure Level (SPL). We aim to identify and isolate them in order to understand the share and contribution due to wind turbine activity, and to test whether and how the wind regime can be considered a proxy for it. Components such as marine traffic and tides have been filtered using statistics and periodicities, while events associated with turbine activity have been identified through their correlation with the wind speed and the typical signature they leave in the spectrograms. Supported by preliminary evidence, the analysis suggests that noise can propagate up to 1400 m from the south-west-tip turbine of the wind farm, where wind speeds exceeding 10 m/s can increase the SPL by approximately 6 dB. Future work will model noise propagation and validate it with new recordings.