Precise Fish Volume Estimation Using Underwater Double Cavity Helmholtz Resonator

Abstract

The precise estimation of fish volume is important for monitoring fish growth. In this study, we fabricated and utilised an underwater double cavity Helmholtz resonator consisting of a generating cavity and a portable light-weight acrylic sample cavity for fish volume estimation. A sinusoidal chirp wave with a frequency range of 100 to 500 Hz was generated and captured using an underwater speaker attached to the generating cavity. As the cumulative volume of both the Japanese rice fish (Oryzias latipes) and the Japanese dace fish (Tribolodon hakonensis) increased in the sample cavity, resonance frequency decreased. For both fish species, a high linear correlation with an R² of 0.99 between the actual and predicted volume was obtained.