Maximum Side-Aspect Target Strength of an Individual Fish

Experiments are described in which the target strengths of a number of individual fish were measured at various frequencies. The results of these experiments are combined with results from six other sources and an empirical equation approximating the maximum side-aspect target strength of an individual fish determined for 1 ⩽ L/λ ⩽ 100, where L is the fish length and λ is the acoustic wavelength. This result is combined with a theoretical estimate of the resonance of a fish containing a swimbladder, to produce a curve approximating the maximum side-aspect target strength of an individual bladder fish for L/λ⩽100.