Modelling underwater sound fields from noise events contained in the ACCOBAMS impulsive noise register to address cumulative impact and acoustic pollution assessment.

The need to monitor and assess marine noise pollution from impulsive signals in European waters has been especially tackled by the European Union through the Marine Strategy Framework Directive, whereby the establishment of a register of impulsive noise sources is recommended. Today, this register is primarily meant at recording data on the location and time of the use of noise sources, with the aim of computing and mapping the number of days with impulsive noise over a year and over a regular spatial grid (Pulse-block days). While this system allows identifying areas with concentrating noise-producing human activities, it leaves many questions unsolved such as those addressing the cumulative acoustic effects on marine wildlife of multiple sources. In the Mediterranean Sea and the Black Sea, the development of a common noise register following the framework described above is led by ACCOBAMS in cooperation with the Barcelona Convention. This work presents an approach for enriching the ACCOBAMS register with sound propagation models based on the following steps: modelling the propagation of sound from noise events contained in the register; applying sound exposure criteria available in the scientific literature to convert estimated sound fields into potential disturbance to marine life; calculating and mapping the area and periods of disturbance. Test results obtained by applying this approach are presented and can be used to feed the discussion on the future development of impact indicators for the Mediterranean and the Black Sea. Further, this approach opens interesting doors by showing the potential of the register to act as a planning tool, and to contribute to processes belonging to different legal frameworks such as the EU regulation on the Environmental Impact Assessments and Strategic Environmental Assessments, and for the implementation of the provisions of different international fora on environmental conservation.