Sperm whales (Physeter macrocephalus) in the Mediterranean Sea are classified as “Endangered,” and face threats from bycatch, vessel strikes, pollution, and declining prey availability. Despite their ecological significance, key aspects of their diving and acoustic behavior remain poorly understood, largely due to the limitations of traditional visual boat-based surveys. As part of the DIVES project (Deep-sea Investigation with a View to Protect Elusive Cetacean Species), we address this gap by integrating passive acoustic monitoring (PAM) and non-invasive bio-logging tags in the central Mediterranean Sea. PAM efforts involve various autonomous recorders and the IPANEMA cabled observatory, featuring an array of four broadband hydrophones for real-time monitoring off eastern Sicily. Additionally, suction-cup bio-logging tags have been deployed to capture fine-scale diving and vocal activity. These analyses reveal dives reaching depths of about 1300 m, frequent use of echolocation clicks during both descent and bottom phases, and communication signals, with the dominance of the Mediterranean-specific 3 + 1 coda pattern. During active foraging behavior, the typical buzzes signals (creaks) were linked to specific kinematic signatures. These findings offer new insights into the behavior of this endangered population, contributing to conservation efforts and advancing non-invasive methods for deep-sea cetacean monitoring.
Capasso et al. (Wed,) studied this question.