| Summary: | The vocalization source level distribution is estimated for four distinct baleen whale species: blue, fin, minke and sei, in the Gulf of Maine. The vocalizations were received using a large-aperture, densely sampled, coherent hydrophone array system deployed to monitor the marine mammals over instantaneous wide areas using the passive ocean acoustic waveguide remote sensing technique. For each baleen whale species, between 500 to over 2,000 measured vocalizations with significantly high signal-to-noise ratios after coherent beamforming and localized with high accuracy (< 5% localization error) over ranges spanning 1.2 to 53.7 km are included in the analysis. The received baleen whale mean and maximum vocalization pressure levels are corrected for broadband transmission loss modelled using a range-dependent parabolic equation based ocean acoustic waveguide propagation model. The source level distribution is characterized by the following mean and standard deviation in units of dB re 1 Pa at 1 m, 178.4 ? 4.9 for blue whale type D calls, 185.2 ? 6.1 for fin whale 20 Hz pulses, 178.1 ? 5.3 for minke whale buzzes, and 183.1 ? 6.0 for sei whale double downsweep calls. The source distribution is essential for determining the detection region for the baleen whale vocalizations for both a single sensor as well as a coherent hydrophone array system.
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