Beaked whale acoustic versus visual detection

Because of their sensitivity to anthropogenic noise, research on beaked whale habitat is particularly important. During 2010 and 2011, NATO Undersea Research Centre (NURC) conducted sea trials dedicated to marine mammals, in areas of potential beaked whale habitat. The first one took place in North Eastern Atlantic Ocean, Southwest of Portugal, and the second one took place in the Gulf of Genoa, Mediterranean Sea. For both trials: weather conditions allowing, during daylight there were two teams of visual observers, working in two shifts, scanning the horizon and taking note of marine mammal encounters. Acoustic data were collected with the CPAM (Compact Passive Acoustic Monitoring), designed by NURC. The total usable bandwidth is up to 80 kHz. The CPAM was deployed at a depth between 100 and 200 m for about 20 h a day Beaked whale detection obtained by visual observers and by passive acoustic are analyzed. The number of detections and the information obtained by each method are compared. The advantages a...