Affiliation: | 1. Graduate Program in Marine Biology, College of Charleston of Charleston, Charleston, South Carolina Department of Natural Sciences, University of South Carolina Beaufort, Bluffton, South Carolina These authors contributed equally to this manuscript. Contribution: Formal analysis, Investigation, Methodology, Visualization, Writing - original draft, Writing - review & editing;2. Department of Natural Sciences, University of South Carolina Beaufort, Bluffton, South Carolina Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK Contribution: Data curation, Investigation, Methodology, Writing - review & editing;3. Graduate Program in Marine Biology, College of Charleston of Charleston, Charleston, South Carolina National Marine Mammal Foundation, San Diego, California Contribution: Writing - review & editing;4. Graduate Program in Marine Biology, College of Charleston of Charleston, Charleston, South Carolina Department of Health and Human Performance, College of Charleston of Charleston, Charleston, South Carolina Contribution: Formal analysis, Writing - review & editing;5. Department of Natural Sciences, University of South Carolina Beaufort, Bluffton, South Carolina Graduate Program in Environmental and Sustainability Studies, College of Charleston of Charleston, Charleston, South Carolina Contribution: Data curation, Methodology, Writing - review & editing;6. Graduate Program in Marine Biology, College of Charleston of Charleston, Charleston, South Carolina |
Abstract: | Passive acoustics has been used extensively to study bottlenose dolphins; yet very few studies have examined the spatial, temporal, and environmental influences on vocalization types (echolocation, burst pulse sounds, and whistles), and few are long-term and provide high temporal resolution over multiple years. We used data from 2013 to 2018 to establish baseline acoustic patterns for bottlenose dolphins in the May River estuary, South Carolina. We deployed acoustic recorders at six stations during 2013–2014 and three stations during 2015–2018, with locations spanning the entire estuary (headwaters to the mouth). We discovered that acoustic detection of dolphins varied not only spatially, but also yearly, monthly, and tidally. Higher numbers of echolocation bouts, burst pulse sounds, and whistles were detected at the mouth as compared to the headwaters. At the mouth, vocalization detections were greatest in fall and winter for multiple years, and echolocation detection was greatest during falling and low tides. This study provides an example of another tool, long-term passive acoustics monitoring, to better understand spatial and temporal distribution of dolphins in a typical salt marsh estuary, that can be applied to other ecosystems throughout the southeastern United States and globally. |