Sperm whale clicks observed with a cabled observatory on deep seafloor in Sagami Bay

Through the waveform analysis of click sounds that have been observed with a bottom installed single hydrophone of the multidisciplinary cabled observatory on deep seafloor off Hatsushima Island in Sagami Bay, some features of sperm whales, such as diving depth, speed and body length were studied. In addition, echo intensity variations of Acoustic Doppler Current Profiler (ADCP) were observed that indicate diving whales roughly consistent with the result of waveform analysis on hydrophone data. Those results show that multidisciplinary long term observation with the cabled observatory might be a strong apparatus to investigate the ecology of whales along with a huge amount of its past data, even though it did not aimed at the whale monitoring originally.