ESR 54:311-329 (2024)  -  DOI: https://doi.org/10.3354/esr01336

ABSTRACT: Studying underwater soundscapes of critical habitats of marine mammals can provide valuable information on the acoustic environment utilized by sound-reliant animals. For the endangered Hawaiian monk seal Neomonachus schauinslandi (HMS), the acoustic scene of their aquatic habitats is poorly understood. We measured ambient noise levels and characterized sound sources at 4 shallow critical habitats of the HMS. Broadband levels ranged from 107.8-123.4 dB re 1 µPa. Octave band levels showed diel patterns associated with biological and anthropogenic sources that mask HMS vocalizations. Biological sources dominated the soundscape at all sites. We opportunistically recorded 2 large-scale geophonic events: Hurricane Douglas (Category 4) and a 6.2 magnitude earthquake. This study provides the first description of underwater soundscapes at critical habitats of the HMS across its expansive range. These measurements serve as a baseline for future studies to understand the impacts of human activities on underwater soundscapes.

KEY WORDS: Acoustics · Vocalizations · Marine mammals · Geophony · Anthropogenic noise · Hawaiian monk seal

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Cite this article as: Parnell K, Merkens K, Huetz C, Charrier I, Robinson SJ, Pacini A, Bejder L (2024) Underwater soundscapes within critical habitats of the endangered Hawaiian monk seal: implications for conservation. Endang Species Res 54:311-329. https://doi.org/10.3354/esr01336 Export citation Share:    Facebook - - linkedIn