Comparing Observed and Theoretical Acoustic Range of the Sciaena umbra Calls in a Marine Protected Area

This study investigates the acoustic propagation of reproductive calls produced by the brown meagre (Sciaena umbra) within the Miramare Marine Protected Area (Gulf of Trieste, Italy). Sound pressure levels recorded along three radial transects extending from the center of vocal activity were compared with pre- dictions from transmission loss modeling. The presence of chorusing was assessed through manual inspection of audio recordings and spectrograms. Although the shallow coastal environment imposes strong constraints on sound transmission, choruses were detectable at distances of up to 400 m under low anthropogenic sound conditions. This detection range, together with the spatial distribution of calling activity, suggests the presence of multiple aggregations and supports the hypothesis of lek-like reproductive behavior. Because chorusing is a reliable proxy for spawning in this Vulnerable species, these findings underscore the ecological importance of the Miramare MPA in facilitating successful repro- duction and sustaining long-term population viability