Off-line observation system based on acoustic video camera for understanding behavior of underwater life

We have developed an off-line acoustic video camera system for observation of underwater lives. This system consists of acoustic video camera “DIDSON”, power control unit and frame unit. DIDSON is commercially available acoustic lens-based imaging sonar. It can work even in turbid or dark water where optical systems fail. The power control unit was newly developed. It controls power supply to DIDSON and allows DIDSON to work in stand-alone mode at seafloor. This acoustic video camera system was used in order to observe behaviors of dugongs living in coastal area of Mindanao Island, Philippines, as its first field trial. Though the acoustic video camera system could not capture the images of dugongs due to limitation of observation period, quality of the captured images was good enough to indicate that the off-line acoustic video camera system has a practical use.