Characterization of the acoustic community of vocal fishes in the Azores

Abstract

Sounds produced by teleost fishes are an important component of marine soundscapes, making passive acoustic monitoring (PAM) an effective way to map the presence of vocal fishes with a minimal impact on ecosystems. Based on a literature review, we list the known soniferous fish species occurring in Azorean waters and compile their sounds. We also describe new fish sounds recorded in Azores seamounts. From the literature, we identified 20 vocal fish species present in Azores. We analysed long-term acoustic recordings carried out since 2008 in Condor and Princesa Alice seamounts and describe 20 new putative fish sound sequences. Although we propose candidates as the source of some vocalizations, this study puts into evidence the myriad of fish sounds lacking species identification. In addition to identifying new sound sequences, we provide the first marine fish sound library for Azores. Our acoustic library will allow to monitor soniferous fish species for conservation and management purposes.

Vocal repertoire and consistency of call features in the meagre Argyrosomous regius (Asso, 1801)

“…However, acoustic indices, such as the Acoustic Complexity Index, cannot discern between fish sound diversity and abundance [ 26 ]. In this context, approaches based on manual or automated detection of fish sound types and sequences appear to be the key for describing high resolution fish biodiversity dynamics through passive acoustic monitoring [ 11 , 27 , 28 ].…”

Temporal dynamics in diversity patterns of fish sound production in the Condor seamount (Azores, NE Atlantic)

“…Hence, the reduced time after the reserve establishment (2 years) may have not been enough to produce positive observable effects in species and sound abundances as reserve effects typically take more than 10 years to get established (Edgar et al 2014). Indeed, more recent data from demersal longline fishing in Condor revealed an increase in the abundance and biomass of the commercial specie Pagelus bogaraveo (Giacomello, personal communication;Rosa et al 2018), which is a potentially vocal species (Carriço et al 2019). Future studies comparing acoustic data with fishing surveys from more recent years, are necessary to ascertain the relation between the acoustic and the fishing data observed in this study and its relation with MPA effects.…”

“…In Carriço et al (2019) we uncovered an important diversity of fish sounds from two Azorean seamounts. Here, we report on the annual, seasonal and diel patterns of 1 occurrence of fish sounds recorded by acoustic data loggers at ca.…”

“…Fig. S1; see alsoCarriço et al 2019). The remaining sound sequences, due to their lower abundance (abundance range: 1-21 sounds found in the analysed dataset (20 days per year, 3 years)) were included in a single category called 'Others'.…”

“…2.5 Patterns of fish assemblages Data on the temporal and spatial patterns of variation of benthic and benthopelagic fish assemblages on the Condor seamount were obtained from a previously published study (Menezes & Giacomello 2013) that collected longline samples in the 151-1200 m depth interval, from 2003 to 2012 (between September and November). These samples were conducted in autumn: 19 and 20 of November 2003; 15-25 of September 2009; 25 September 2010 to 1 of October 2010; 22 of September to 7 of October 2011; 29 of September to 15 of October 2012; according to Table 1 in Menezes & Giacomello 2013.From all the species inTable 2from, we selected the species that were caught with the fishing gear at 150-250 m, whose depth range was within the presumed detection range of the hydrophone (see results) and noted the ones that were vocal or potentially vocal (species belonging to the same genus or family of other confirmed vocal species;Carriço et al 2019). Although some fish species could theoretically be detected several hundred meters away we chose to select fish with its upper catch distribution limit ranging from 150-250 m, to be conservative.…”