State of Play in Marine Soundscape Assessments

Abstract

A soundscape is the recording of all sounds present in an area, creating a holistic view of the acoustic profile in an ecosystem. Studying acoustic parameters of marine soundscapes as a whole has been shown to give an indication of the health status of the location, as well as correlate to which species may be present and using the area. With the rapid innovation of technology, especially data storage and declining cost of equipment, marine soundscape research is fast increasing, and these previous limitations have been switched for computing capacity for data analysis. Here, we perform a systematic assessment of literature of marine soundscape studies, from 1978, when the first soundscape study was reported, until 2021. We identified 200 primary research studies that recorded soundscapes and captured their geographical location, depth, habitat, duration of the study, and number of sites in each study. Using this data, we summarize the state of play in marine soundscapes studies, and identify knowledge gaps in the spatial coverage, depth profiles, habitat representation and study duration. Spatially, studies are biased towards the northern hemisphere. They are also more prevalent in more easily accessible ecosystems, in order from most to least studied, in coastal (38%), pelagic (20%), tropical coral reef (17%), rocky reef (7%), polar (5.5%), seagrass meadows, oyster reef and kelp/algal forest (<5% each) areas, with zones of cold-water coral the least studied (0.3%). Continuing the trend of accessibility, studies also tended to focus on shallow ecosystems. Most recordings (68%) were conducted in the upper 50 m, with 13% in 50-200 m depths, and only 0.6% at a depth >4000 m. With anthropogenic noise and other pollution sources increasing globally, these gaps in research should be further addressed, especially as they pertain to vulnerable ecosystems, many of which are affected by global climate change and anthropogenic influences. It is crucial that marine soundscape studies continue to be developed and pursued, to establish baselines for healthy ecosystems and/or document recovery following management actions.

Worldwide Soundscapes: a synthesis of passive acoustic monitoring across realms

“…Previous quantitative syntheses were typically systematic reviews focusing on single realms (Greenhalgh et al 2020; Havlik, Predragovic, and Duarte 2022; Sugai et al 2019), freshwater syntheses were rather focused on bioacoustics, and the only cross-realm synthesis known to us was a qualitative review (Lindseth and Lobel 2018). However, recent case studies underline the potential of ecoacoustics for cross-realm syntheses: the discovery of universal distributions of sound and silence durations for freshwater, marine, and terrestrial realms (de Sousa et al 2022) and the demonstration that soundscapes can track resilience and recovery of terrestrial and marine animals from natural disasters (Gottesman et al 2021).…”

“…The state of ecoacoustic research has only been reviewed separately for each realm for now (Duarte et al 2021; Greenhalgh et al 2020; Havlik, Predragovic, and Duarte 2022; Lindseth and Lobel 2018; Sugai et al 2019), but cross-realm syntheses bear potential to answer new questions. PAM can help to address fundamental questions in ecology (Ross et al 2023).…”

“…Interdisciplinary syntheses have great potential, as the state of ecoacoustic research has only been reviewed separately for each realm for now (Duarte et al 2021; Greenhalgh et al 2020; Havlik, Predragovic, and Duarte 2022; Lindseth and Lobel 2018; Sugai et al 2019). What questions could be answered with such holistic approaches?…”

Submarine optical fiber communication provides an unrealized deep-sea observation network

“…Ocean soundscapes have been highlighted as an integrative measure of biological, human, and physical processes in the ocean 3 , which could capture the desired metrics synoptically. However, the density and frequency of measurements of essential ocean variables 4 , such as temperature 1 or soundscapes 3 , 5 remain minimal in the deep sea. Therefore, addressing our current gap in observing the deep sea and informing a pending assessment of the environment and ecology of the deep sea and its changes are major goals of the UN Decade of Ocean Science 6 .…”

Acoustic twilight: A year‐long seafloor monitoring unveils phenological patterns in the abyssal soundscape

“…Despite the growing recognition of the ecological importance of sound, the sonic environment in deep-sea ecosystems remains largely uncharted (Bolgan and Parmentier 2020;Havlik et al 2022). To date, only a handful of studies have investigated soundscapes in the bathyal zone over several months (Melc on et al 2012;Bohnenstiehl et al 2013;Wiggins et al 2016;Martin et al 2019;Warren et al 2021;Weiss et al 2021), and even fewer have done so in the abyssal and hadal zones (Dziak et al 2017;Chen et al 2021).…”