Footprint of Sound Emissions from Fishing Vessels in the Adriatic Sea

An underwater sound modeling assessment was performed of fishing boats in the Jabuka/Pomo Pit Fisheries Restricted Area (FRA) in the Adriatic Sea, offshore of Italy and Croatia. Underwater sound fields were modeled for two types of fishing vessels employing either longlines (LLS) or otter-bottom trawls (OTB). Estimated broadband source levels ranged between 149 and 153 dB re 1 μPa m for LLS vessels and 171 and 175 dB re 1 μPa m for OTB vessels. Sound fields were calculated for sound pressure levels (SPL) to compare with available impact criteria. The SPL thresholds for recoverable barotrauma injury and temporary hearing threshold shift (TTS) pressure-sensitive fish from Popper et al. (2014) of 170 and 158 dB re 1 μPa, respectively, were not reached for any vessel at any location. The modeled levels considered only the sound generated from fishing vessels and did not account for other sound sources. The maximum modeled range to the behavioral response threshold for marine mammals from NOAA (ESA Section 7 consultation tools for marine mammals on the west coast (webpage), 2019) of 120 dB re 1 μPa was 0.91 km. Modeling results indicate that underwater noise produced by LLS and OTB on marine fauna do not represent a threat to biodiversity.