EU Marine Strategy Framework Directive-Compatible Approaches for Impulsive Noise Assessment

The Marine Strategy Framework Directive (MSFD) (Directive 2008/56/EC) promotes sustainable use of the seas by requiring member states to achieve and maintain Good Environmental Status (GES), including underwater noise as one of of the eleven specific criteria for evaluating GES. In 2022, the EU established quantitative threshold values for addressing the consequences of impulsive underwater noise input into the marine environment. In this chapter, a data-driven stepwise approach is introduced for the implementation of an MSFD compatible assessment methodology. Corresponding standardized practices are presented. For the data-driven evaluation of regional requirements and of the applicability of harmonized methodologies within EU regions, exemplary regional case studies were performed for the Baltic Sea, North Sea, and Mediterranean Sea. Further, the estimation of effect ranges and corresponding risks of adverse effects is important for an impulsive noise assessment. Regional differences in the marine environment were addressed. Main challenges of impulsive noise propagation modelling were identified based on both numerical and analytical/empirical propagation modelling. Finally, recommendations for the impulsive noise registries are presented.