Antarctic blue whales in the southern Indian Ocean: a multi-year and multi-site database of Z-call detections

As part of the OHASISBIO project, since January 2010, a network of 6 to 8 autonomous hydrophones is deployed in the southern Indian Ocean (Fig. 1) to monitor the low-frequency sounds (0-120 Hz) carried by the ocean. These acoustic data provide unique information on the seasonal presence of several species and sub-species of large baleen whales. Among them, the Antarctic blue whale (Balaenoptera musculus intermedia) has a distinct call between 18 and 26 Hz, easily recognizable by its Z-shape in a time-frequency diagram. We designed an automatic Z-detector (Socheleau et al., 2015) to cense the Z-calls in our multi-year, multi-site acoustic dataset. The resulting database consists of several metrics: time of detection of each individual call, the ambient noise level between 40 and 60 Hz, and the ratio between the whale chorus between 25 and 27 Hz over the noise level between 30 and 33 Hz.

The rationale for these metrics and the interpretation of the results can be found in the paper by Leroy et al. (2016; see reference below).

Figure 1: Acoustic records available for Antarctic blue whale Z-call detections.

Figure 2: Acoustic records available for Antarctic blue whale Z-call detections.

Date (Publication): 2016-09

Date (Revision): 2021-05-12

Other citation details: Leroy Emmanuelle C., Royer Jean-Yves, Bonnel Julien, Samaran Flore (2016). Antarctic blue whales in the southern Indian Ocean: a multi-year and multi-site database of Z-call detections. SEANOE. https://doi.org/10.17882/46124

Credit: The authors wish to thank the Captains and crews of RV Marion Dufresne for the successful deployments and recoveries of the hydrophones of the OHASISBIO experiment and of ORV Sagar Kanya for the recovery of the RAMA hydrophone. French cruises were funded by the French Polar Institute (IPEV; cruises VT109/112-MD174/175, VT115-MD185, VT119-MD189, VT128-MD193, VT135-MD197, VT141-MD200 and VT146-MD201), with additional support from INSU-CNRS. We thank NOAA/PMEL and INCOIS for the opportunity to recover the RAMA hydrophone.

The hydroacoustic stations were funded by INSU-CNRS and by Région Bretagne (CPER ODO 2007-2015).

Author

CNRS & Université de Brest, Laboratoire Géosciences Océan, IUEM rue Dumont d’Urville, 29280 Plouzané - Leroy Emmanuelle C.

Author

CNRS & Université de Brest, Laboratoire Géosciences Océan, IUEM rue Dumont d’Urville, 29280 Plouzané - Royer Jean-Yves

Author

ENSTA-Bretagne, Lab-STICC, 2 rue François Verny, 29806 Brest Cedex 9 - Bonnel Julien

Author

ENSTA-Bretagne, Lab-STICC, 2 rue François Verny, 29806 Brest Cedex 9 - Samaran Flore

Publisher

SEANOE

Theme

Environment

ODATIS aggregation parameters and Essential Variable names

Marine turtles, birds, mammals

SeaDataNet Parameter Disciplines

Environment

Type de jeux de donnée ODATIS

/Observational data/in-situ

Use limitation: CC-BY-NC (Creative Commons - Attribution, No commercial usage)

Use constraints: Other restrictions

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