LMG 0201A

Cetacean passive acoustics

Sonobuoy deployments and results

Sonobuoys were deployed both when marine mammals were visually detected and also randomly throughout the cruise.A total of 39 sonobuoys was deployed – 34 omnidirectionals (19 of type 41B and 15 of type 57B) and 5 DiFARs (53B).The locations of all the deployments are shown in Figure 2.Species heard on the sonobuoys were blue whales, minke whales, and possibly a fin whale (Figure 2).Sperm whales clicks, as well as unidentified beaked whale species (possibly Hector’s beaked whale) whistles were heard on sonobuoys deployed in the Drake Passage.

Figure 2.Sonobuoy deployment locations with species heard on the sonobuoy marked.Calling whales can be heard at large distances from the sonobuoy so a detected call does not necessarily indicate vicinity of whales.