Environmental constraints drive the partitioning of the soundscape in fishes

Abstract

The underwater environment is more and more being depicted as particularly noisy, and the inventory of calling fishes is continuously increasing. However, it currently remains unknown how species share the soundscape and are able to communicate without misinterpreting the messages. Different mechanisms of interference avoidance have been documented in birds, mammals, and frogs, but little is known about interference avoidance in fishes. How fish thus partition the soundscape underwater remains unknown, as acoustic communication and its organization have never been studied at the level of fish communities. In this study, passive acoustic recordings were used to inventory sounds produced in a fish community (120 m depth) in an attempt to understand how different species partition the acoustic environment. We uncovered an important diversity of fish sounds, and 16 of the 37 different sounds recorded were sufficiently abundant to use in a quantitative analysis. We show that sonic activity allows a clear distinction between a diurnal and a nocturnal group of fishes. Moreover, frequencies of signals made during the day overlap, whereas there is a clear distinction between the different representatives of the nocturnal callers because of a lack of overlap in sound frequency. This first demonstration, to our knowledge, of interference avoidance in a fish community can be understood by the way sounds are used. In diurnal species, sounds are mostly used to support visual display, whereas nocturnal species are generally deprived of visual cues, resulting in acoustic constraints being more important.

Species Richness (of Insects) Drives the Use of Acoustic Space in the Tropics

“…Some studies have suggested that species avoid competition by partitioning acoustic space in time or frequency [9][10][11][12][13][14], while others have reported temporal synchrony and spectral overlap among species [15,16]. These studies focused on individual taxonomic groups (e.g., fish [14], birds [17], insects [18] and anurans [10,12,15], so any interactions that may have shaped the observed use of acoustic space would be restricted to within a group [16]. To our knowledge, no study has assessed patterns of frequency and time use for all species in the acoustic community (0-22 kHz), and few studies have evaluated how the use of acoustic space varies across a gradient of species richness [19,20].…”

Coral reef soundscapes : spatiotemporal variability and links to species assemblages

“…Alternatively, it is possible that broad-scale community-level summaries, such as the ones presented here, mask nuanced differences among reefs that might emerge from more fine-scale assessments that examine and quantify the sounds being produced, and not just the overall trend. Indeed, the broad trends in reef soundscapes have now been described for several reef systems; however, more granular investigations looking at the occurrence patterns of individual sound types are far rarer (but see Ruppe et al, 2015). Such studies are labor intensive when manual identification of sounds is required.…”

Soundscapes offer unique opportunities for studies of fish communities

“…This includes the "space" to effectively communicate with conspecifics (3). In PNAS, Ruppé et al (4) document apparent resource partitioning in the acoustic communication behavior of a community of nocturnal marine fishes found in a cave environment on the rocky coastline of South Africa. They recorded and analyzed 2,793 instances of 17 distinctive sounds that differed in peak frequency and pulsing characteristics.…”

“…The Ruppé et al study (4) tackles several emerging topics in the area of marine soundscape research. By illuminating differences in daytime and nighttime patterns of acoustic signaling, they are contributing to a developing body of knowledge on the impact of environmental constraints such as daily and lunar cycles on marine soundscapes (e.g., ref.…”