MEPS 608:183-197 (2019)  -  DOI: https://doi.org/10.3354/meps12812

ABSTRACT: Assessing fish biodiversity patterns is a major concern in aquatic science and conservation. To be effectively used, fish diversity assessments benefit from the use of integrated complementary approaches. Passive acoustics has received increasing attention as a non-invasive, long-term monitoring tool, as it uses biological sounds produced incidentally or intentionally as natural tags to identify and estimate animal diversity. In the marine environment, there is little evidence about the link between taxonomic diversity (different species) and acoustic diversity (different sound types). Here we used underwater visual census fish data collected over multiple years from 3 sites within a Mediterranean Marine Protected Area as comprehensive information on local fish assemblages to be compared with acoustic recordings obtained in September 2015. Richness, diversity and community similarity indices as well as abundance analyses revealed a strong relationship between taxonomic diversity and acoustic diversity. Overall, acoustic communities showed pronounced differences between the study sites that were not observed in the respective taxonomic assemblages. Despite the lower number of sound type categories (12) compared to taxa (53) and the short recording period, passive acoustics showed a high discriminating potential, which supports its suitability as a complementary approach to visual-based surveys. The fish sound repertoire established here was organized into a dichotomous tree based on acoustic characteristics that are valuable for the development of automatic acoustic biodiversity appraisal tools for resource monitoring and management.

KEY WORDS: Biodiversity · Fish sounds · Species richness · Biophony · Underwater visual census · Passive acoustic monitoring · Soundscape · Community ecology