Source levels of dugong (Dugong dugon) vocalizations recorded in Shark Bay

Research in Shark Bay, Western Australia, reveals that dugongs (Dugong dugon) produce vocalizations with distinct source levels, ranging from 135 to 158 dB re 1 μPa at 1 m. These findings provide critical insights into the acoustic communication of dugongs, which are often active in shallow, turbid waters where visual cues are limited. The study used passive acoustic recording, a non-invasive method for detecting vocal marine animals, to estimate source levels for five call types: chirp (two variants), bark, squeak, and quack. Unlike traditional aerial surveys, this approach avoids logistical constraints and biases related to animal availability or perception. By analyzing recordings taken at 5.1 m from tagged dugongs in March 2012, the study offers a foundation for understanding the detection range of dugong calls, which could improve monitoring efforts for this vulnerable marine species.

Parsons, M. J. G., Holley, D., & McCauley, R. D. (2013). Source levels of dugong (Dugong dugon) vocalizations recorded in Shark Bay. The Journal of the Acoustical Society of America, 134(3), 2582–2588. https://doi.org/10.1121/1.4816583