LAUSR

It is well established that attenuation due to swim bladder bearing fish can have profound effects on transmission loss (TL) in continental shelf and slope environments (Weston, 1967; Diachok, 1999). Realistic estimates of geoacoustic parameters from TL measurements in such environments may be derived by application of the concurrent bio and geo inversion method (Diachok and Wales, 2005; Diachok and Wadsworth, 2014). This method assumes that the biological environment may be characterized by bio-alpha (attenuation coefficient within the layer), layer depth, and layer thickness. Application of this method to broadband TL measurements between 0.3 and 5 kHz in the Santa Barbara Channel resulted in realistic estimates of geo and bioacoustic parameters. Inverted geoacoustic parameters were consistent with coincident core and chirp sonar measurements. Inverted bioacoustic parameters were consistent with concurrent measurements of fish depths and length distributions of dominant species. The latter permitted cal...