The Northern Adriatic Sea (NAS) represents a transboundary area encompassing three different nations (Italy, Slovenia and Croatia) that is characterized by many anthropic activities (maritime traffic, mussel and fish farms, industrial activities and tourist development) but also by high biodiversity and protected areas. This paper reviews the sea ambient noise data collected along the NAS coasts in three study areas, ie. (i) the Gulf of Trieste (ii) the Venice Lagoon (Italy) and (iii) the Cres and Losinj Archipelago (Croatia), from 2006 to 2015.
Sound Pressure Level (SPL) wideband values range from 88 dB re 1 uPa to 154 dB re 1 uPa (125 ± 11 dB re 1 uPa, average value). For 63 Hz and 125 Hz 1/3 octave bands SPL levels do not exceed 132 and 136 dB re 1 uPa, respectively. Data indicate spatial variations in the noise levels between the investigated areas with more similar levels between Trieste and Venice in contrast to the Cres and Losinj archipelago. The SPLs recorded in this study are higher than reported for other coastal areas characterized by vessel traffic, confirming the need to further studies in the area.