2010, Subacoustech, Ormonde, Subsea Acoustic Survey

This series presents the results of underwater noise monitoring carried out by Subacoustech Environmental Ltd between May and June 2010 during impact piling operations to install jacket pile foundations at the Ormonde Offshore Windfarm (Ormonde) site. The results have been interpreted in terms of the potential avoidance response this noise might have on selected marine species. Field measurements were carried out using calibrated hydrophones along four transects extending up to 30 km from turbine positions, supplemented by background noise recordings, literature review, and comparative analysis with established injury and behavioral criteria (US NMFS, Southall et al. 2007, UK BERR). The study employed both unweighted and species-specific dBht and M-weighted acoustic metrics to analyze noise exposure, accounting for hearing sensitivities and including predictive modeling for impact range estimation. Results showed low likelihood of lethal effects but potential for physical injury within 13 m, auditory injury for harbour porpoise up to 570 m, and behavioral avoidance at substantial distances (up to 17 km for porpoise).