This presentation provides an overview of the significant contribution that Clay and his students made to the understanding of the statistical nature of the acoustic signals scattered from fish and the methods for removing the effect of the beam pattern from the received echo statistics to measure the underlying fish backscattering statistics. By making measurements of the acoustic scattering from live fish, he showed that the probability density function of the envelope amplitude of the echo signal scattered from the fish could be modeled by a Ricean PDF. He further showed that as the ratio of the length of the fish to the acoustic wavelength became large, the PDF became Rayleigh distributed. Clay and his students were interested in using the measured echo statistics to obtain information about the size distribution of the fish producing the scattering. They developed a method for deconvolving the effect of the acoustic beam pattern from the received echo statistics to provide an estimate of the fish sca...