In recent years, many studies have evaluated the effects of anthropogenic acoustic disturbance on marine organisms. Sounds associated with shipping, seismic surveys, sonar, and many other such sources induce several types of effect on fish and marine mammals. In this regard, the European Marine Strategy Framework Directive 2008/56/EC has not only defined underwater acoustic noise as “the intentional or accidental introduction of acoustic energy in the water column from impulsive and diffuse sources”, but has also expressly identified it as a form of pollution.
In 2014, the first Italian proposal has been defined with the aim of developing a widespread monitoring plan for sub-regions in European Union waters with respect to two different sub-programs concerning impulsive (Descriptor 11.1) and continuous low frequency (Descriptor 11.2) sounds. The objective of Marine Strategy Framework Directive is the implementation of a recording system for temporal-spatial data regarding impulsive sound sources arising from anthropogenic activities. The pressure, for Descriptor 11.1, is measured by evaluating the source level, or a suitable proxy for anthropogenic sound sources, measured over the frequency band 10 Hz–10 kHz (and up to 40 kHz for cetacean detection), that could have an impact on marine organisms.
The Descriptor 11.2 would monitor trends in the ambient noise level within the 1/3 octave bands 63 and 125 Hz (centre frequency) (re 1 μΡa RMS; average noise level in these octave bands over a year) via observation stations. This monitoring plan aims to obtain noise maps of sea regions for the frequency band 10 Hz–10 kHz (and up to 40 kHz for cetacean detection) by improving existing geophysical/acoustic observation stations, e.g. those of the National Institute of Geophysics and Volcanology (INGV) and the National Institute of Nuclear Physics (INFN), as well as other medium- and long-term monitoring stations. The program also wants to define the level of damage caused by underwater noise, using underwater noise as an example to evaluate the impact of this type of noise on different marine organisms.
Maritime spatial planning (MSP) and integrated coastal management (ICZM) have to employ an ecosystem-based approach that ensures the protection of the natural resources and provides the basis for carrying out the various monitoring activities. The Italian monitoring proposal on Descriptor 11 of Marine Strategy Framework Directive (MSFD) was used in order to analyze the strategic vision of the integrated maritime policy (IMP) between MSFD and MSP programs in terms of achieving Good Environmental Status (GES).