Comparing coastal marine habitats by combining passive acoustics with metagenomics

Abstract

Past studies have combined passive acoustic monitoring with environmental genetic methods to detect target organisms, however, no studies to date have employed metagenomics concurrent with passive acoustic monitoring of soundscapes for comparison of marine habitats. The present study used both approaches simultaneously for holistic observation of marine habitats to reveal information beyond using either technique independently. Water samples for metabarcoding (four primer sets) were collected during periods of passive acoustic monitoring from three different marine habitats, each at four different geographic locations along the New Hampshire/Maine coastlines. Multivariate analyses compared discrimination among habitat types and geographic locations by analyzing acoustic metrics generated using the Soundscape Code and metagenomic taxonomic assignments. Passive acoustic monitoring provided insight into environmental features that were unobservable with metagenomics, especially anthropogenic activity and geophysical processes, whereas metagenomics provided a more complete picture of the biological composition of habitats through detection of organisms that were not actively producing sound. This enables simultaneous evaluation of biological and functional connectivity of marine habitats by detecting what organisms are present and their contributions to the soundscape. In future, genetic and acoustic indicators will be used for prediction of substrate characteristics and sound sources to model acoustic propagation environments.