First assessment of underwater sound levels in the Northern Adriatic Sea at the basin scale

Abstract

The protection of marine habitats from human-generated underwater noise is an emerging challenge. Baseline information on sound levels, however, is poorly available, especially in the Mediterranean Sea. To bridge this knowledge gap, the SOUNDSCAPE project ran a basin-scale, cross-national, long-term underwater monitoring in the Northern Adriatic Sea. A network of nine monitoring stations, characterized by different natural conditions and anthropogenic pressures, ensured acoustic data collection from March 2020 to June 2021, including the full lockdown period related to the COVID-19 pandemic. Calibrated stationary recorders featured with an omnidirectional Neptune Sonar D60 Hydrophone recorded continuously 24 h a day (48 kHz sampling rate, 16 bit resolution). Data were analysed to Sound Pressure Levels (SPLs) with a specially developed and validated processing app. Here, we release the dataset composed of 20 and 60 seconds averaged SPLs (one-third octave, base 10) output files and a Python script to postprocess them. This dataset represents a benchmark for scientists and policymakers addressing the risk of noise impacts on marine fauna in the Mediterranean Sea and worldwide.

Who Goes There? Evaluating the Performance of a CNN for Monitoring Delphinid Presences to That of the C-Pod Within Diverse Marine Soundscapes

“…This work encourages the collection of broadband acoustic to provide context to detector performances and the ambient environment in which the animals are residing. As marine habitats get noisier a range of national and international regulations 35,36,37 have arisen to understand and quantify noise levels regionally. Using a CNN as part of the analysis pipeline allows automated signal extraction to occur in a timely manner and encourages researchers to gather large PAM datasets which can be used to address a wealth of ecological questions.…”

Whales and dolphins of the Adriatic Sea

“…In Croatian waters, noise caused by boat traffic is known to affect dolphin whistle frequencies (Rako-Gospić and Picciulin, 2016) and one study showed a significant seasonal displacement of dolphins from areas with intense traffic of leisure boats (Rako et al, 2013a). In recent years, extensive underwater acoustic data in the northern and central Adriatic Sea were recorded in the context of project SOUNDSCAPE, and this effort has provided baseline information on sound levels (Petrizzo et al, 2023;Picciulin et al, 2023), useful to assess acoustic threats to marine life including cetaceans.…”

First basin scale spatial-temporal characterization of underwater sound in the Mediterranean Sea

“…Typically, a measurement period lasted 3 months, after which each recorder needed to be recovered to download data and to remove biological fouling. The SOUNDSCAPE measurement period covers 16 months (from 1 March 2020 to 30 June 2021); the data coverage per each monitoring station is represented by Figure S1 (Supplementary Materials) and it is described in detail by 23 .…”

“…Other stations, however, were in proximity to important conservation areas like Natura 2000 sites (Parco del Conero, Italia, MS3, and Losinj archipelago, Croatia, MS6) or sh reproductive areas (Žirje, Croatia; MS7). This study aims to describe the spatial and temporal variations in the NAS ambient sound pressure levels over one year period, on the base of the recently released dataset 23 and to discuss the results in the light of available literature.…”

“…The elaboration of all the collected data to obtain Sound Pressure Levels was performed by the same acoustic processing tool (Audio Noise Processing App; ANP) based on a Python code speci cally developed for SOUNDSCAPE by the University of Gdansk together with CNR. Detailed information on the processing chain is given in23 . Used metric in this paper is the 20 seconds averaged SPLs data in the one third decidecade octave band (hereafter TOB), according to 58 .…”