Acoustic localization, validation, and characterization of Rice's whale calls

Area of Science:

• Marine Biology
• Bioacoustics
• Conservation Science

Background:

• Rice's whale is critically endangered, residing in the Gulf of Mexico.
• Understanding their spatiotemporal occurrence is vital for conservation.
• Accurate identification of their vocalizations is crucial for passive acoustic monitoring.

Purpose of the Study:

• To validate the source of potential Rice's whale calls.
• To characterize the vocal repertoire of Rice's whales.
• To establish foundational data for conservation using passive acoustic monitoring.

Main Methods:

• Concurrent visual and acoustic surveys were conducted.
• Acoustic-directed approaches were used to verify sound sources.
• Sonobuoys and passive acoustic tagging were employed to record and attribute calls.

Main Results:

• 79% of acoustic-directed approaches resulted in sightings of balaenopterid whales.
• 10 Rice's whales were positively identified, linking specific calls to the species.
• Long-moan, downsweep, and tonal sequences were attributed to Rice's whales; a new low-frequency downsweep sequence was identified.

Conclusions:

• The study successfully validated and characterized the Rice's whale call repertoire.
• This provides essential data for utilizing passive acoustic monitoring in Rice's whale conservation.
• The findings support improved understanding and protection strategies for this endangered species.