Inter- and intra-annual frequency variations of large-whale calls in the southern Indian ocean ...

• Main Authors: Leroy, Emmanuelle C, Royer, Jean-Yves, Bonnel, Julien, Samaran, Flore
• Format: Dataset
• Language: unknown
• Published: SEANOE 2017
• Subjects: Antarc*; Antarctic; Balaenoptera musculus; baleen whales; Blue whale
• Online Access: https://dx.doi.org/10.17882/51007; https://www.seanoe.org/data/00399/51007/

In the past decades, an inter-annual decline of the frequency of blue whale calls is been observed worldwide (Mc Donald et al., 2009), along with an intra-annual variation, best described for the Antarctic blue whale calls (Balaenoptera musculus intermedia) (Gavrilov et al., 2011; Gavrilov et al., 2012; Miller et al., 2014). The reasons for this decline and variations are still not understood. During the DEFLOHYDRO project, a network of 3 autonomous hydrophones (MAD, NEAMS and SWAMS sites; Fig. 1) was deployed in the southern Indian Ocean from November 2006 to January 2008 to monitor the low-frequency sounds (0-120 Hz) carried by the ocean, and provided a complete year of acoustic data in 2007. It was continued by the OHASISBIO project, a network of 6 to 8 autonomous hydrophones deployed in January 2010 and still operational (August 2017; Fig. 1). These acoustic data sets reveal the seasonal presence of several species and sub-species of large baleen whales: the Antarctic blue whale (Balaenoptera musculus ...