2023_programme: Underwater noise risk assessment using uncertain noise maps and measurements

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  • Session: 20. Underwater noise in the EU Marine Strategy Framework Directive: monitoring and impacts on marine ecosystems
    Organiser(s): Jakob Tougaard, Aristides Prospathopoulos and Emmanuel Skarsoulis
  • Lecture: Underwater noise risk assessment using uncertain noise maps and measurements
    Paper ID: 2039
    Author(s): Dellong David, Ceyrac Laura, Le Courtois Florent
    Presenter: Dellong David
    Abstract: In the context of emerging regulations on underwater noise pollution in the Marine Strategy Framework Directive (MSFD-D11C2), member states of the EU are mandated to assess continuous noise pollution in their waters. This remains a complicated task to perform, and advances on the methodology and threshold values to consider were recently made. The methodology provided by the Technical Group on Noise (TG-Noise) heavily relies on modelled noise maps, but the uncertainty of the modelling process remains a concern. Moreover, this methodology could in principle be applied to in-situ measurements, but it remains to be demonstrated. Measurements are not exempt from uncertainties, and valuable indicators should be extracted before proceeding to the continuous noise pollution assessment.\nThis study investigates the impact of noise map uncertainties on the resulting risk assessment and explore a methodology for an assessment based on measurement data.\nA case-study set in the French EEZ is presented and relies on noise maps modelled during the JONAS project as well as acoustic measurements from the Shom. The methodology applied follows the recommendation of TG-Noise. Noise maps uncertainties were propagated up to the risk assessment using a Monte Carlo method. The results are investigated to provide insights on the risk assessment sensitivity regarding the model uncertainties. Certain threshold values appear to be more sensitive than others to the model uncertainties. Measurement data were processed to extract only the continuous noise component of the signal. The measurement-based assessment at local points is partially following the TG-Noise methodology (spatial dimension being absent). The results of the assessment performed on the model and the measurements at these locations will be compared and presented.
  • Corresponding author: Dr David DELLONG
    Affiliation: Research fellow at Shom
    Country: France
    e-mail:

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