Underwater soundscape of marine protected areas in the south Brazilian coast

•First underwater sound monitoring of two marine protected areas (XJSP and LSMSP) in the Santos Port vicinity, Brazil.•24-h mean spectrograms underline periodicities evinced in collected data.•Although shipping noise is present, daily biological chorus dominate the underwater soundscapes at both sites.•The origin of biological choruses seems to be related to fish shoals.•By its proximity to the port, XJSP shows the highest SPL values.

The Laje de Santos Marine State Park (LSMSP) and Xixová-Japuí State Park (XJSP) are two protected areas (PA), close to the Santos Bay in the south Brazilian coast. The region encompasses both important biodiversity and anthropogenic activities. This study aims to serve as a first reference survey of the underwater soundscape of these PAs. Additionally it evaluates the presence of the anthropogenic and biological sound in these areas. One month of continuous recorded underwater sound, at selected locations in XJSP and LSMSP, is used in this study. The data were characterized by its spectral content and by the temporal evolution of Sound Pressure Levels (SPL). Both locations showed sound events with daily periodicities, mainly related with boats and fish chorus.